Merge branch 'LTCv3-with-presence' into master

pom.xml

@@ -7,7 +7,8 @@
 	<packaging>jar</packaging>
 	<properties>
 		<skipTests>true</skipTests>
-		<bitcoinj.version>0.15.5</bitcoinj.version>
+		<altcoinj.version>bf9fb80</altcoinj.version>
+		<bitcoinj.version>0.15.6</bitcoinj.version>
 		<bouncycastle.version>1.64</bouncycastle.version>
 		<build.timestamp>${maven.build.timestamp}</build.timestamp>
 		<ciyam-at.version>1.3.8</ciyam-at.version>
@@ -199,6 +200,10 @@
 							<pattern>org.qortal.api.model**</pattern>
 							<template>${project.build.sourceDirectory}/org/qortal/data/package-info.java</template>
 						</package>
+						<package>
+							<pattern>org.qortal.api.model.**</pattern>
+							<template>${project.build.sourceDirectory}/org/qortal/data/package-info.java</template>
+						</package>
 					</packages>
 					<outputDirectory>${project.build.directory}/generated-sources/package-info</outputDirectory>
 				</configuration>
@@ -383,6 +388,11 @@
 			<name>project</name>
 			<url>file:${project.basedir}/lib</url>
 		</repository>
+		<!-- jitpack for build-on-demand of altcoinj -->
+		<repository>
+			<id>jitpack.io</id>
+			<url>https://jitpack.io</url>
+		</repository>
 	</repositories>
 	<dependencies>
 		<!-- https://mvnrepository.com/artifact/org.codehaus.mojo/build-helper-maven-plugin -->
@@ -417,6 +427,12 @@
 			<artifactId>bitcoinj-core</artifactId>
 			<version>${bitcoinj.version}</version>
 		</dependency>
+		<!-- For Litecoin, etc. support, requires bitcoinj -->
+		<dependency>
+			<groupId>com.github.jjos2372</groupId>
+			<artifactId>altcoinj</artifactId>
+			<version>${altcoinj.version}</version>
+		</dependency>
 		<!-- Utilities -->
 		<dependency>
 			<groupId>com.googlecode.json-simple</groupId>

src/main/java/org/qortal/api/ApiError.java

@@ -15,7 +15,7 @@ public enum ApiError {
 	// COMMON
 	// UNKNOWN(0, 500),
 	JSON(1, 400),
-	// NO_BALANCE(2, 422),
+	INSUFFICIENT_BALANCE(2, 402),
 	// NOT_YET_RELEASED(3, 422),
 	UNAUTHORIZED(4, 403),
 	REPOSITORY_ISSUE(5, 500),
@@ -126,10 +126,10 @@ public enum ApiError {
 	// Groups
 	GROUP_UNKNOWN(1101, 404),
 
-	// Bitcoin
-	BTC_NETWORK_ISSUE(1201, 500),
-	BTC_BALANCE_ISSUE(1202, 402),
-	BTC_TOO_SOON(1203, 408);
+	// Foreign blockchain
+	FOREIGN_BLOCKCHAIN_NETWORK_ISSUE(1201, 500),
+	FOREIGN_BLOCKCHAIN_BALANCE_ISSUE(1202, 402),
+	FOREIGN_BLOCKCHAIN_TOO_SOON(1203, 408);
 
 	private static final Map<Integer, ApiError> map = stream(ApiError.values()).collect(toMap(apiError -> apiError.code, apiError -> apiError));
 

src/main/java/org/qortal/api/ApiService.java

@@ -43,6 +43,7 @@ import org.qortal.api.websocket.ActiveChatsWebSocket;
 import org.qortal.api.websocket.AdminStatusWebSocket;
 import org.qortal.api.websocket.BlocksWebSocket;
 import org.qortal.api.websocket.ChatMessagesWebSocket;
+import org.qortal.api.websocket.PresenceWebSocket;
 import org.qortal.api.websocket.TradeBotWebSocket;
 import org.qortal.api.websocket.TradeOffersWebSocket;
 import org.qortal.settings.Settings;
@@ -200,6 +201,7 @@ public class ApiService {
 			context.addServlet(ChatMessagesWebSocket.class, "/websockets/chat/messages");
 			context.addServlet(TradeOffersWebSocket.class, "/websockets/crosschain/tradeoffers");
 			context.addServlet(TradeBotWebSocket.class, "/websockets/crosschain/tradebot");
+			context.addServlet(PresenceWebSocket.class, "/websockets/presence");
 
 			// Start server
 			this.server.start();

src/main/java/org/qortal/api/model/CrossChainBitcoinP2SHStatus.java

@@ -1,31 +0,0 @@
-package org.qortal.api.model;
-
-import java.math.BigDecimal;
-
-import javax.xml.bind.annotation.XmlAccessType;
-import javax.xml.bind.annotation.XmlAccessorType;
-
-import io.swagger.v3.oas.annotations.media.Schema;
-
-@XmlAccessorType(XmlAccessType.FIELD)
-public class CrossChainBitcoinP2SHStatus {
-
-	@Schema(description = "Bitcoin P2SH address", example = "3CdH27kTpV8dcFHVRYjQ8EEV5FJg9X8pSJ (mainnet), 2fMiRRXVsxhZeyfum9ifybZvaMHbQTmwdZw (testnet)")
-	public String bitcoinP2shAddress;
-
-	@Schema(description = "Bitcoin P2SH balance")
-	public BigDecimal bitcoinP2shBalance;
-
-	@Schema(description = "Can P2SH redeem yet?")
-	public boolean canRedeem;
-
-	@Schema(description = "Can P2SH refund yet?")
-	public boolean canRefund;
-
-	@Schema(description = "Secret extracted by P2SH redeemer")
-	public byte[] secret;
-
-	public CrossChainBitcoinP2SHStatus() {
-	}
-
-}

src/main/java/org/qortal/api/model/CrossChainBitcoinyHTLCStatus.java

@@ -0,0 +1,31 @@
+package org.qortal.api.model;
+
+import java.math.BigDecimal;
+
+import javax.xml.bind.annotation.XmlAccessType;
+import javax.xml.bind.annotation.XmlAccessorType;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+
+@XmlAccessorType(XmlAccessType.FIELD)
+public class CrossChainBitcoinyHTLCStatus {
+
+	@Schema(description = "P2SH address", example = "3CdH27kTpV8dcFHVRYjQ8EEV5FJg9X8pSJ (mainnet), 2fMiRRXVsxhZeyfum9ifybZvaMHbQTmwdZw (testnet)")
+	public String bitcoinP2shAddress;
+
+	@Schema(description = "P2SH balance")
+	public BigDecimal bitcoinP2shBalance;
+
+	@Schema(description = "Can HTLC redeem yet?")
+	public boolean canRedeem;
+
+	@Schema(description = "Can HTLC refund yet?")
+	public boolean canRefund;
+
+	@Schema(description = "Secret used by HTLC redeemer")
+	public byte[] secret;
+
+	public CrossChainBitcoinyHTLCStatus() {
+	}
+
+}

src/main/java/org/qortal/api/model/CrossChainOfferSummary.java

@@ -4,7 +4,7 @@ import javax.xml.bind.annotation.XmlAccessType;
 import javax.xml.bind.annotation.XmlAccessorType;
 import javax.xml.bind.annotation.adapters.XmlJavaTypeAdapter;
 
-import org.qortal.crosschain.BTCACCT;
+import org.qortal.crosschain.AcctMode;
 import org.qortal.data.crosschain.CrossChainTradeData;
 
 import io.swagger.v3.oas.annotations.media.Schema;
@@ -16,26 +16,41 @@ public class CrossChainOfferSummary {
 	// Properties
 
 	@Schema(description = "AT's Qortal address")
-	public String qortalAtAddress;
+	private String qortalAtAddress;
 
 	@Schema(description = "AT creator's Qortal address")
-	public String qortalCreator;
+	private String qortalCreator;
+
+	@Schema(description = "AT creator's ephemeral trading key-pair represented as Qortal address")
+	private String qortalCreatorTradeAddress;
 
 	@XmlJavaTypeAdapter(value = org.qortal.api.AmountTypeAdapter.class)
 	private long qortAmount;
 
+	@Schema(description = "Bitcoin amount - DEPRECATED: use foreignAmount")
 	@XmlJavaTypeAdapter(value = org.qortal.api.AmountTypeAdapter.class)
+	@Deprecated
 	private long btcAmount;
 
+	@Schema(description = "Foreign blockchain amount")
+	@XmlJavaTypeAdapter(value = org.qortal.api.AmountTypeAdapter.class)
+	private long foreignAmount;
+
 	@Schema(description = "Suggested trade timeout (minutes)", example = "10080")
 	private int tradeTimeout;
 
-	private BTCACCT.Mode mode;
+	@Schema(description = "Current AT execution mode")
+	private AcctMode mode;
 
 	private long timestamp;
 
+	@Schema(description = "Trade partner's Qortal receiving address")
 	private String partnerQortalReceivingAddress;
 
+	private String foreignBlockchain;
+
+	private String acctName;
+
 	protected CrossChainOfferSummary() {
 		/* For JAXB */
 	}
@@ -43,12 +58,16 @@ public class CrossChainOfferSummary {
 	public CrossChainOfferSummary(CrossChainTradeData crossChainTradeData, long timestamp) {
 		this.qortalAtAddress = crossChainTradeData.qortalAtAddress;
 		this.qortalCreator = crossChainTradeData.qortalCreator;
+		this.qortalCreatorTradeAddress = crossChainTradeData.qortalCreatorTradeAddress;
 		this.qortAmount = crossChainTradeData.qortAmount;
-		this.btcAmount = crossChainTradeData.expectedBitcoin;
+		this.foreignAmount = crossChainTradeData.expectedForeignAmount;
+		this.btcAmount = this.foreignAmount; // Duplicate for deprecated field
 		this.tradeTimeout = crossChainTradeData.tradeTimeout;
 		this.mode = crossChainTradeData.mode;
 		this.timestamp = timestamp;
 		this.partnerQortalReceivingAddress = crossChainTradeData.qortalPartnerReceivingAddress;
+		this.foreignBlockchain = crossChainTradeData.foreignBlockchain;
+		this.acctName = crossChainTradeData.acctName;
 	}
 
 	public String getQortalAtAddress() {
@@ -59,6 +78,10 @@ public class CrossChainOfferSummary {
 		return this.qortalCreator;
 	}
 
+	public String getQortalCreatorTradeAddress() {
+		return this.qortalCreatorTradeAddress;
+	}
+
 	public long getQortAmount() {
 		return this.qortAmount;
 	}
@@ -67,11 +90,15 @@ public class CrossChainOfferSummary {
 		return this.btcAmount;
 	}
 
+	public long getForeignAmount() {
+		return this.foreignAmount;
+	}
+
 	public int getTradeTimeout() {
 		return this.tradeTimeout;
 	}
 
-	public BTCACCT.Mode getMode() {
+	public AcctMode getMode() {
 		return this.mode;
 	}
 
@@ -83,10 +110,18 @@ public class CrossChainOfferSummary {
 		return this.partnerQortalReceivingAddress;
 	}
 
+	public String getForeignBlockchain() {
+		return this.foreignBlockchain;
+	}
+
+	public String getAcctName() {
+		return this.acctName;
+	}
+
 	// For debugging mostly
 
 	public String toString() {
-		return String.format("%s: %s", this.qortalAtAddress, this.mode.name());
+		return String.format("%s: %s", this.qortalAtAddress, this.mode);
 	}
 
 }

src/main/java/org/qortal/api/model/CrossChainTradeSummary.java

@@ -6,6 +6,8 @@ import javax.xml.bind.annotation.adapters.XmlJavaTypeAdapter;
 
 import org.qortal.data.crosschain.CrossChainTradeData;
 
+import io.swagger.v3.oas.annotations.media.Schema;
+
 // All properties to be converted to JSON via JAXB
 @XmlAccessorType(XmlAccessType.FIELD)
 public class CrossChainTradeSummary {
@@ -15,9 +17,14 @@ public class CrossChainTradeSummary {
 	@XmlJavaTypeAdapter(value = org.qortal.api.AmountTypeAdapter.class)
 	private long qortAmount;
 
+	@Deprecated
+	@Schema(description = "DEPRECATED: use foreignAmount instead")
 	@XmlJavaTypeAdapter(value = org.qortal.api.AmountTypeAdapter.class)
 	private long btcAmount;
 
+	@XmlJavaTypeAdapter(value = org.qortal.api.AmountTypeAdapter.class)
+	private long foreignAmount;
+
 	protected CrossChainTradeSummary() {
 		/* For JAXB */
 	}
@@ -25,7 +32,8 @@ public class CrossChainTradeSummary {
 	public CrossChainTradeSummary(CrossChainTradeData crossChainTradeData, long timestamp) {
 		this.tradeTimestamp = timestamp;
 		this.qortAmount = crossChainTradeData.qortAmount;
-		this.btcAmount = crossChainTradeData.expectedBitcoin;
+		this.foreignAmount = crossChainTradeData.expectedForeignAmount;
+		this.btcAmount = this.foreignAmount;
 	}
 
 	public long getTradeTimestamp() {
@@ -40,4 +48,7 @@ public class CrossChainTradeSummary {
 		return this.btcAmount;
 	}
 
+	public long getForeignAmount() {
+		return this.foreignAmount;
+	}
 }

src/main/java/org/qortal/api/model/SimpleForeignTransaction.java

@@ -0,0 +1,157 @@
+package org.qortal.api.model;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.Objects;
+
+import javax.xml.bind.annotation.XmlAccessType;
+import javax.xml.bind.annotation.XmlAccessorType;
+
+@XmlAccessorType(XmlAccessType.FIELD)
+public class SimpleForeignTransaction {
+
+	public static class AddressAmount {
+		public final String address;
+		public final long amount;
+
+		protected AddressAmount() {
+			/* For JAXB */
+			this.address = null;
+			this.amount = 0;
+		}
+
+		public AddressAmount(String address, long amount) {
+			this.address = address;
+			this.amount = amount;
+		}
+	}
+
+	private String txHash;
+	private long timestamp;
+
+	private List<AddressAmount> inputs;
+
+	public static class Output {
+		public final List<String> addresses;
+		public final long amount;
+
+		protected Output() {
+			/* For JAXB */
+			this.addresses = null;
+			this.amount = 0;
+		}
+
+		public Output(List<String> addresses, long amount) {
+			this.addresses = addresses;
+			this.amount = amount;
+		}
+	}
+	private List<Output> outputs;
+
+	private long totalAmount;
+	private long fees;
+
+	private Boolean isSentNotReceived;
+
+	protected SimpleForeignTransaction() {
+		/* For JAXB */
+	}
+
+	private SimpleForeignTransaction(Builder builder) {
+		this.txHash = builder.txHash;
+		this.timestamp = builder.timestamp;
+		this.inputs = Collections.unmodifiableList(builder.inputs);
+		this.outputs = Collections.unmodifiableList(builder.outputs);
+
+		Objects.requireNonNull(this.txHash);
+		if (timestamp <= 0)
+			throw new IllegalArgumentException("timestamp must be positive");
+
+		long totalGrossAmount = this.inputs.stream().map(addressAmount -> addressAmount.amount).reduce(0L, Long::sum);
+		this.totalAmount = this.outputs.stream().map(addressAmount -> addressAmount.amount).reduce(0L, Long::sum);
+
+		this.fees = totalGrossAmount - this.totalAmount;
+
+		this.isSentNotReceived = builder.isSentNotReceived;
+	}
+
+	public String getTxHash() {
+		return this.txHash;
+	}
+
+	public long getTimestamp() {
+		return this.timestamp;
+	}
+
+	public List<AddressAmount> getInputs() {
+		return this.inputs;
+	}
+
+	public List<Output> getOutputs() {
+		return this.outputs;
+	}
+
+	public long getTotalAmount() {
+		return this.totalAmount;
+	}
+
+	public long getFees() {
+		return this.fees;
+	}
+
+	public Boolean isSentNotReceived() {
+		return this.isSentNotReceived;
+	}
+
+	public static class Builder {
+		private String txHash;
+		private long timestamp;
+		private List<AddressAmount> inputs = new ArrayList<>();
+		private List<Output> outputs = new ArrayList<>();
+		private Boolean isSentNotReceived;
+
+		public Builder txHash(String txHash) {
+			this.txHash = Objects.requireNonNull(txHash);
+			return this;
+		}
+
+		public Builder timestamp(long timestamp) {
+			if (timestamp <= 0)
+				throw new IllegalArgumentException("timestamp must be positive");
+
+			this.timestamp = timestamp;
+			return this;
+		}
+
+		public Builder input(String address, long amount) {
+			Objects.requireNonNull(address);
+			if (amount < 0)
+				throw new IllegalArgumentException("amount must be zero or positive");
+
+			AddressAmount input = new AddressAmount(address, amount);
+			inputs.add(input);
+			return this;
+		}
+
+		public Builder output(List<String> addresses, long amount) {
+			Objects.requireNonNull(addresses);
+			if (amount < 0)
+				throw new IllegalArgumentException("amount must be zero or positive");
+
+			Output output = new Output(addresses, amount);
+			outputs.add(output);
+			return this;
+		}
+
+		public Builder isSentNotReceived(Boolean isSentNotReceived) {
+			this.isSentNotReceived = isSentNotReceived;
+			return this;
+		}
+
+		public SimpleForeignTransaction build() {
+			return new SimpleForeignTransaction(this);
+		}
+	}
+
+}

src/main/java/org/qortal/api/model/TradeBotRespondRequest.java

@@ -1,23 +0,0 @@
-package org.qortal.api.model;
-
-import javax.xml.bind.annotation.XmlAccessType;
-import javax.xml.bind.annotation.XmlAccessorType;
-
-import io.swagger.v3.oas.annotations.media.Schema;
-
-@XmlAccessorType(XmlAccessType.FIELD)
-public class TradeBotRespondRequest {
-
-	@Schema(description = "Qortal AT address", example = "Aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa")
-	public String atAddress;
-
-	@Schema(description = "Bitcoin BIP32 extended private key", example = "xprv___________________________________________________________________________________________________________")
-	public String xprv58;
-
-	@Schema(description = "Qortal address for receiving QORT from AT", example = "Qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq")
-	public String receivingAddress;
-
-	public TradeBotRespondRequest() {
-	}
-
-}

src/main/java/org/qortal/api/model/crosschain/BitcoinSendRequest.java

@@ -1,4 +1,4 @@
-package org.qortal.api.model;
+package org.qortal.api.model.crosschain;
 
 import javax.xml.bind.annotation.XmlAccessType;
 import javax.xml.bind.annotation.XmlAccessorType;
@@ -9,16 +9,20 @@ import io.swagger.v3.oas.annotations.media.Schema;
 @XmlAccessorType(XmlAccessType.FIELD)
 public class BitcoinSendRequest {
 
-	@Schema(description = "Bitcoin BIP32 extended private key", example = "tprv8ZgxMBicQKsPdahhFSrCdvC1bsWyzHHZfTneTVqUXN6s1wEtZLwAkZXzFP6TbTVGajEB55L1HYLg2aQMecZLXLre5YJcawpdFG66STVAWPJ")
+	@Schema(description = "Bitcoin BIP32 extended private key", example = "tprv___________________________________________________________________________________________________________")
 	public String xprv58;
 
 	@Schema(description = "Recipient's Bitcoin address ('legacy' P2PKH only)", example = "1BitcoinEaterAddressDontSendf59kuE")
 	public String receivingAddress;
 
-	@Schema(description = "Amount of BTC to send")
+	@Schema(description = "Amount of BTC to send", type = "number")
 	@XmlJavaTypeAdapter(value = org.qortal.api.AmountTypeAdapter.class)
 	public long bitcoinAmount;
 
+	@Schema(description = "Transaction fee per byte (optional). Default is 0.00000100 BTC (100 sats) per byte", example = "0.00000100", type = "number")
+	@XmlJavaTypeAdapter(value = org.qortal.api.AmountTypeAdapter.class)
+	public Long feePerByte;
+
 	public BitcoinSendRequest() {
 	}
 

src/main/java/org/qortal/api/model/crosschain/LitecoinSendRequest.java

@@ -0,0 +1,29 @@
+package org.qortal.api.model.crosschain;
+
+import javax.xml.bind.annotation.XmlAccessType;
+import javax.xml.bind.annotation.XmlAccessorType;
+import javax.xml.bind.annotation.adapters.XmlJavaTypeAdapter;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+
+@XmlAccessorType(XmlAccessType.FIELD)
+public class LitecoinSendRequest {
+
+	@Schema(description = "Litecoin BIP32 extended private key", example = "tprv___________________________________________________________________________________________________________")
+	public String xprv58;
+
+	@Schema(description = "Recipient's Litecoin address ('legacy' P2PKH only)", example = "LiTecoinEaterAddressDontSendhLfzKD")
+	public String receivingAddress;
+
+	@Schema(description = "Amount of LTC to send", type = "number")
+	@XmlJavaTypeAdapter(value = org.qortal.api.AmountTypeAdapter.class)
+	public long litecoinAmount;
+
+	@Schema(description = "Transaction fee per byte (optional). Default is 0.00000100 LTC (100 sats) per byte", example = "0.00000100", type = "number")
+	@XmlJavaTypeAdapter(value = org.qortal.api.AmountTypeAdapter.class)
+	public Long feePerByte;
+
+	public LitecoinSendRequest() {
+	}
+
+}

src/main/java/org/qortal/api/model/crosschain/TradeBotCreateRequest.java

@@ -1,9 +1,11 @@
-package org.qortal.api.model;
+package org.qortal.api.model.crosschain;
 
 import javax.xml.bind.annotation.XmlAccessType;
 import javax.xml.bind.annotation.XmlAccessorType;
 import javax.xml.bind.annotation.adapters.XmlJavaTypeAdapter;
 
+import org.qortal.crosschain.SupportedBlockchain;
+
 import io.swagger.v3.oas.annotations.media.Schema;
 
 @XmlAccessorType(XmlAccessType.FIELD)
@@ -12,22 +14,30 @@ public class TradeBotCreateRequest {
 	@Schema(description = "Trade creator's public key", example = "2zR1WFsbM7akHghqSCYKBPk6LDP8aKiQSRS1FrwoLvoB")
 	public byte[] creatorPublicKey;
 
-	@Schema(description = "QORT amount paid out on successful trade", example = "80.40200000")
+	@Schema(description = "QORT amount paid out on successful trade", example = "80.40000000", type = "number")
 	@XmlJavaTypeAdapter(value = org.qortal.api.AmountTypeAdapter.class)
 	public long qortAmount;
 
-	@Schema(description = "QORT amount funding AT, including covering AT execution fees", example = "81")
+	@Schema(description = "QORT amount funding AT, including covering AT execution fees", example = "80.50000000", type = "number")
 	@XmlJavaTypeAdapter(value = org.qortal.api.AmountTypeAdapter.class)
 	public long fundingQortAmount;
 
-	@Schema(description = "Bitcoin amount wanted in return", example = "0.00864200")
+	@Deprecated
+	@Schema(description = "Bitcoin amount wanted in return. DEPRECATED: use foreignAmount instead", example = "0.00864200", type = "number", hidden = true)
 	@XmlJavaTypeAdapter(value = org.qortal.api.AmountTypeAdapter.class)
-	public long bitcoinAmount;
+	public Long bitcoinAmount;
+
+	@Schema(description = "Foreign blockchain. Note: default (BITCOIN) to be removed in the future", example = "BITCOIN", implementation = SupportedBlockchain.class)
+	public SupportedBlockchain foreignBlockchain;
+
+	@Schema(description = "Foreign blockchain amount wanted in return", example = "0.00864200", type = "number")
+	@XmlJavaTypeAdapter(value = org.qortal.api.AmountTypeAdapter.class)
+	public Long foreignAmount;
 
 	@Schema(description = "Suggested trade timeout (minutes)", example = "10080")
 	public int tradeTimeout;
 
-	@Schema(description = "Bitcoin address for receiving", example = "1BitcoinEaterAddressDontSendf59kuE")
+	@Schema(description = "Foreign blockchain address for receiving", example = "1BitcoinEaterAddressDontSendf59kuE")
 	public String receivingAddress;
 
 	public TradeBotCreateRequest() {

src/main/java/org/qortal/api/model/crosschain/TradeBotRespondRequest.java

@@ -0,0 +1,29 @@
+package org.qortal.api.model.crosschain;
+
+import javax.xml.bind.annotation.XmlAccessType;
+import javax.xml.bind.annotation.XmlAccessorType;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+
+@XmlAccessorType(XmlAccessType.FIELD)
+public class TradeBotRespondRequest {
+
+	@Schema(description = "Qortal AT address", example = "Aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa")
+	public String atAddress;
+
+	@Deprecated
+	@Schema(description = "Bitcoin BIP32 extended private key. DEPRECATED: use foreignKey instead", hidden = true,
+			example = "xprv___________________________________________________________________________________________________________")
+	public String xprv58;
+
+	@Schema(description = "Foreign blockchain private key, e.g. BIP32 'm' key for Bitcoin/Litecoin starting with 'xprv'",
+			example = "xprv___________________________________________________________________________________________________________")
+	public String foreignKey;
+
+	@Schema(description = "Qortal address for receiving QORT from AT", example = "Qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq")
+	public String receivingAddress;
+
+	public TradeBotRespondRequest() {
+	}
+
+}

src/main/java/org/qortal/api/resource/CrossChainBitcoinACCTv1Resource.java

@@ -0,0 +1,363 @@
+package org.qortal.api.resource;
+
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.media.Content;
+import io.swagger.v3.oas.annotations.media.Schema;
+import io.swagger.v3.oas.annotations.parameters.RequestBody;
+import io.swagger.v3.oas.annotations.responses.ApiResponse;
+import io.swagger.v3.oas.annotations.tags.Tag;
+
+import java.util.Arrays;
+import java.util.Random;
+
+import javax.servlet.http.HttpServletRequest;
+import javax.ws.rs.POST;
+import javax.ws.rs.Path;
+import javax.ws.rs.core.Context;
+import javax.ws.rs.core.MediaType;
+
+import org.qortal.account.PublicKeyAccount;
+import org.qortal.api.ApiError;
+import org.qortal.api.ApiErrors;
+import org.qortal.api.ApiExceptionFactory;
+import org.qortal.api.Security;
+import org.qortal.api.model.CrossChainBuildRequest;
+import org.qortal.api.model.CrossChainSecretRequest;
+import org.qortal.api.model.CrossChainTradeRequest;
+import org.qortal.asset.Asset;
+import org.qortal.crosschain.BitcoinACCTv1;
+import org.qortal.crosschain.Bitcoiny;
+import org.qortal.crosschain.AcctMode;
+import org.qortal.crypto.Crypto;
+import org.qortal.data.at.ATData;
+import org.qortal.data.crosschain.CrossChainTradeData;
+import org.qortal.data.transaction.BaseTransactionData;
+import org.qortal.data.transaction.DeployAtTransactionData;
+import org.qortal.data.transaction.MessageTransactionData;
+import org.qortal.data.transaction.TransactionData;
+import org.qortal.group.Group;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.repository.RepositoryManager;
+import org.qortal.transaction.DeployAtTransaction;
+import org.qortal.transaction.MessageTransaction;
+import org.qortal.transaction.Transaction;
+import org.qortal.transaction.Transaction.TransactionType;
+import org.qortal.transaction.Transaction.ValidationResult;
+import org.qortal.transform.TransformationException;
+import org.qortal.transform.Transformer;
+import org.qortal.transform.transaction.DeployAtTransactionTransformer;
+import org.qortal.transform.transaction.MessageTransactionTransformer;
+import org.qortal.utils.Base58;
+import org.qortal.utils.NTP;
+
+@Path("/crosschain/BitcoinACCTv1")
+@Tag(name = "Cross-Chain (BitcoinACCTv1)")
+public class CrossChainBitcoinACCTv1Resource {
+
+	@Context
+	HttpServletRequest request;
+
+	@POST
+	@Path("/build")
+	@Operation(
+		summary = "Build Bitcoin cross-chain trading AT",
+		description = "Returns raw, unsigned DEPLOY_AT transaction",
+		requestBody = @RequestBody(
+			required = true,
+			content = @Content(
+				mediaType = MediaType.APPLICATION_JSON,
+				schema = @Schema(
+					implementation = CrossChainBuildRequest.class
+				)
+			)
+		),
+		responses = {
+			@ApiResponse(
+				content = @Content(mediaType = MediaType.TEXT_PLAIN, schema = @Schema(type = "string"))
+			)
+		}
+	)
+	@ApiErrors({ApiError.INVALID_PUBLIC_KEY, ApiError.INVALID_DATA, ApiError.INVALID_REFERENCE, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
+	public String buildTrade(CrossChainBuildRequest tradeRequest) {
+		Security.checkApiCallAllowed(request);
+
+		byte[] creatorPublicKey = tradeRequest.creatorPublicKey;
+
+		if (creatorPublicKey == null || creatorPublicKey.length != Transformer.PUBLIC_KEY_LENGTH)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_PUBLIC_KEY);
+
+		if (tradeRequest.hashOfSecretB == null || tradeRequest.hashOfSecretB.length != Bitcoiny.HASH160_LENGTH)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_DATA);
+
+		if (tradeRequest.tradeTimeout == null)
+			tradeRequest.tradeTimeout = 7 * 24 * 60; // 7 days
+		else
+			if (tradeRequest.tradeTimeout < 10 || tradeRequest.tradeTimeout > 50000)
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_DATA);
+
+		if (tradeRequest.qortAmount <= 0)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_DATA);
+
+		if (tradeRequest.fundingQortAmount <= 0)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_DATA);
+
+		// funding amount must exceed initial + final
+		if (tradeRequest.fundingQortAmount <= tradeRequest.qortAmount)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_DATA);
+
+		if (tradeRequest.bitcoinAmount <= 0)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_DATA);
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PublicKeyAccount creatorAccount = new PublicKeyAccount(repository, creatorPublicKey);
+
+			byte[] creationBytes = BitcoinACCTv1.buildQortalAT(creatorAccount.getAddress(), tradeRequest.bitcoinPublicKeyHash, tradeRequest.hashOfSecretB,
+					tradeRequest.qortAmount, tradeRequest.bitcoinAmount, tradeRequest.tradeTimeout);
+
+			long txTimestamp = NTP.getTime();
+			byte[] lastReference = creatorAccount.getLastReference();
+			if (lastReference == null)
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_REFERENCE);
+
+			long fee = 0;
+			String name = "QORT-BTC cross-chain trade";
+			String description = "Qortal-Bitcoin cross-chain trade";
+			String atType = "ACCT";
+			String tags = "QORT-BTC ACCT";
+
+			BaseTransactionData baseTransactionData = new BaseTransactionData(txTimestamp, Group.NO_GROUP, lastReference, creatorAccount.getPublicKey(), fee, null);
+			TransactionData deployAtTransactionData = new DeployAtTransactionData(baseTransactionData, name, description, atType, tags, creationBytes, tradeRequest.fundingQortAmount, Asset.QORT);
+
+			Transaction deployAtTransaction = new DeployAtTransaction(repository, deployAtTransactionData);
+
+			fee = deployAtTransaction.calcRecommendedFee();
+			deployAtTransactionData.setFee(fee);
+
+			ValidationResult result = deployAtTransaction.isValidUnconfirmed();
+			if (result != ValidationResult.OK)
+				throw TransactionsResource.createTransactionInvalidException(request, result);
+
+			byte[] bytes = DeployAtTransactionTransformer.toBytes(deployAtTransactionData);
+			return Base58.encode(bytes);
+		} catch (TransformationException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.TRANSFORMATION_ERROR, e);
+		} catch (DataException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
+		}
+	}
+
+	@POST
+	@Path("/trademessage")
+	@Operation(
+		summary = "Builds raw, unsigned 'trade' MESSAGE transaction that sends cross-chain trade recipient address, triggering 'trade' mode",
+		description = "Specify address of cross-chain AT that needs to be messaged, and signature of 'offer' MESSAGE from trade partner.<br>"
+			+ "AT needs to be in 'offer' mode. Messages sent to an AT in any other mode will be ignored, but still cost fees to send!<br>"
+			+ "You need to sign output with trade private key otherwise the MESSAGE transaction will be invalid.",
+		requestBody = @RequestBody(
+			required = true,
+			content = @Content(
+				mediaType = MediaType.APPLICATION_JSON,
+				schema = @Schema(
+					implementation = CrossChainTradeRequest.class
+				)
+			)
+		),
+		responses = {
+			@ApiResponse(
+				content = @Content(
+					schema = @Schema(
+						type = "string"
+					)
+				)
+			)
+		}
+	)
+	@ApiErrors({ApiError.INVALID_PUBLIC_KEY, ApiError.INVALID_ADDRESS, ApiError.INVALID_CRITERIA, ApiError.REPOSITORY_ISSUE})
+	public String buildTradeMessage(CrossChainTradeRequest tradeRequest) {
+		Security.checkApiCallAllowed(request);
+
+		byte[] tradePublicKey = tradeRequest.tradePublicKey;
+
+		if (tradePublicKey == null || tradePublicKey.length != Transformer.PUBLIC_KEY_LENGTH)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_PUBLIC_KEY);
+
+		if (tradeRequest.atAddress == null || !Crypto.isValidAtAddress(tradeRequest.atAddress))
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_ADDRESS);
+
+		if (tradeRequest.messageTransactionSignature == null || !Crypto.isValidAddress(tradeRequest.messageTransactionSignature))
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_ADDRESS);
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			ATData atData = fetchAtDataWithChecking(repository, tradeRequest.atAddress);
+			CrossChainTradeData crossChainTradeData = BitcoinACCTv1.getInstance().populateTradeData(repository, atData);
+
+			if (crossChainTradeData.mode != AcctMode.OFFERING)
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+
+			// Does supplied public key match trade public key?
+			if (!Crypto.toAddress(tradePublicKey).equals(crossChainTradeData.qortalCreatorTradeAddress))
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_PUBLIC_KEY);
+
+			TransactionData transactionData = repository.getTransactionRepository().fromSignature(tradeRequest.messageTransactionSignature);
+			if (transactionData == null)
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.TRANSACTION_UNKNOWN);
+
+			if (transactionData.getType() != TransactionType.MESSAGE)
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.TRANSACTION_INVALID);
+
+			MessageTransactionData messageTransactionData = (MessageTransactionData) transactionData;
+			byte[] messageData = messageTransactionData.getData();
+			BitcoinACCTv1.OfferMessageData offerMessageData = BitcoinACCTv1.extractOfferMessageData(messageData);
+			if (offerMessageData == null)
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.TRANSACTION_INVALID);
+
+			// Good to make MESSAGE
+
+			byte[] aliceForeignPublicKeyHash = offerMessageData.partnerBitcoinPKH;
+			byte[] hashOfSecretA = offerMessageData.hashOfSecretA;
+			int lockTimeA = (int) offerMessageData.lockTimeA;
+
+			String aliceNativeAddress = Crypto.toAddress(messageTransactionData.getCreatorPublicKey());
+			int lockTimeB = BitcoinACCTv1.calcLockTimeB(messageTransactionData.getTimestamp(), lockTimeA);
+
+			byte[] outgoingMessageData = BitcoinACCTv1.buildTradeMessage(aliceNativeAddress, aliceForeignPublicKeyHash, hashOfSecretA, lockTimeA, lockTimeB);
+			byte[] messageTransactionBytes = buildAtMessage(repository, tradePublicKey, tradeRequest.atAddress, outgoingMessageData);
+
+			return Base58.encode(messageTransactionBytes);
+		} catch (DataException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
+		}
+	}
+
+	@POST
+	@Path("/redeemmessage")
+	@Operation(
+		summary = "Builds raw, unsigned 'redeem' MESSAGE transaction that sends secrets to AT, releasing funds to partner",
+		description = "Specify address of cross-chain AT that needs to be messaged, both 32-byte secrets and an address for receiving QORT from AT.<br>"
+			+ "AT needs to be in 'trade' mode. Messages sent to an AT in any other mode will be ignored, but still cost fees to send!<br>"
+			+ "You need to sign output with account the AT considers the trade 'partner' otherwise the MESSAGE transaction will be invalid.",
+		requestBody = @RequestBody(
+			required = true,
+			content = @Content(
+				mediaType = MediaType.APPLICATION_JSON,
+				schema = @Schema(
+					implementation = CrossChainSecretRequest.class
+				)
+			)
+		),
+		responses = {
+			@ApiResponse(
+				content = @Content(
+					schema = @Schema(
+						type = "string"
+					)
+				)
+			)
+		}
+	)
+	@ApiErrors({ApiError.INVALID_PUBLIC_KEY, ApiError.INVALID_ADDRESS, ApiError.INVALID_DATA, ApiError.INVALID_CRITERIA, ApiError.REPOSITORY_ISSUE})
+	public String buildRedeemMessage(CrossChainSecretRequest secretRequest) {
+		Security.checkApiCallAllowed(request);
+
+		byte[] partnerPublicKey = secretRequest.partnerPublicKey;
+
+		if (partnerPublicKey == null || partnerPublicKey.length != Transformer.PUBLIC_KEY_LENGTH)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_PUBLIC_KEY);
+
+		if (secretRequest.atAddress == null || !Crypto.isValidAtAddress(secretRequest.atAddress))
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_ADDRESS);
+
+		if (secretRequest.secretA == null || secretRequest.secretA.length != BitcoinACCTv1.SECRET_LENGTH)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_DATA);
+
+		if (secretRequest.secretB == null || secretRequest.secretB.length != BitcoinACCTv1.SECRET_LENGTH)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_DATA);
+
+		if (secretRequest.receivingAddress == null || !Crypto.isValidAddress(secretRequest.receivingAddress))
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_ADDRESS);
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			ATData atData = fetchAtDataWithChecking(repository, secretRequest.atAddress);
+			CrossChainTradeData crossChainTradeData = BitcoinACCTv1.getInstance().populateTradeData(repository, atData);
+
+			if (crossChainTradeData.mode != AcctMode.TRADING)
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+
+			String partnerAddress = Crypto.toAddress(partnerPublicKey);
+
+			// MESSAGE must come from address that AT considers trade partner
+			if (!crossChainTradeData.qortalPartnerAddress.equals(partnerAddress))
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_ADDRESS);
+
+			// Good to make MESSAGE
+
+			byte[] messageData = BitcoinACCTv1.buildRedeemMessage(secretRequest.secretA, secretRequest.secretB, secretRequest.receivingAddress);
+			byte[] messageTransactionBytes = buildAtMessage(repository, partnerPublicKey, secretRequest.atAddress, messageData);
+
+			return Base58.encode(messageTransactionBytes);
+		} catch (DataException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
+		}
+	}
+
+	private ATData fetchAtDataWithChecking(Repository repository, String atAddress) throws DataException {
+		ATData atData = repository.getATRepository().fromATAddress(atAddress);
+		if (atData == null)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.ADDRESS_UNKNOWN);
+
+		// Must be correct AT - check functionality using code hash
+		if (!Arrays.equals(atData.getCodeHash(), BitcoinACCTv1.CODE_BYTES_HASH))
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+
+		// No point sending message to AT that's finished
+		if (atData.getIsFinished())
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+
+		return atData;
+	}
+
+	private byte[] buildAtMessage(Repository repository, byte[] senderPublicKey, String atAddress, byte[] messageData) throws DataException {
+		long txTimestamp = NTP.getTime();
+
+		// senderPublicKey could be ephemeral trade public key where there is no corresponding account and hence no reference
+		String senderAddress = Crypto.toAddress(senderPublicKey);
+		byte[] lastReference = repository.getAccountRepository().getLastReference(senderAddress);
+		final boolean requiresPoW = lastReference == null;
+
+		if (requiresPoW) {
+			Random random = new Random();
+			lastReference = new byte[Transformer.SIGNATURE_LENGTH];
+			random.nextBytes(lastReference);
+		}
+
+		int version = 4;
+		int nonce = 0;
+		long amount = 0L;
+		Long assetId = null; // no assetId as amount is zero
+		Long fee = 0L;
+
+		BaseTransactionData baseTransactionData = new BaseTransactionData(txTimestamp, Group.NO_GROUP, lastReference, senderPublicKey, fee, null);
+		TransactionData messageTransactionData = new MessageTransactionData(baseTransactionData, version, nonce, atAddress, amount, assetId, messageData, false, false);
+
+		MessageTransaction messageTransaction = new MessageTransaction(repository, messageTransactionData);
+
+		if (requiresPoW) {
+			messageTransaction.computeNonce();
+		} else {
+			fee = messageTransaction.calcRecommendedFee();
+			messageTransactionData.setFee(fee);
+		}
+
+		ValidationResult result = messageTransaction.isValidUnconfirmed();
+		if (result != ValidationResult.OK)
+			throw TransactionsResource.createTransactionInvalidException(request, result);
+
+		try {
+			return MessageTransactionTransformer.toBytes(messageTransactionData);
+		} catch (TransformationException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.TRANSFORMATION_ERROR, e);
+		}
+	}
+
+}

src/main/java/org/qortal/api/resource/CrossChainBitcoinResource.java

@@ -0,0 +1,167 @@
+package org.qortal.api.resource;
+
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.media.ArraySchema;
+import io.swagger.v3.oas.annotations.media.Content;
+import io.swagger.v3.oas.annotations.media.Schema;
+import io.swagger.v3.oas.annotations.parameters.RequestBody;
+import io.swagger.v3.oas.annotations.responses.ApiResponse;
+import io.swagger.v3.oas.annotations.tags.Tag;
+
+import java.util.List;
+
+import javax.servlet.http.HttpServletRequest;
+import javax.ws.rs.POST;
+import javax.ws.rs.Path;
+import javax.ws.rs.core.Context;
+import javax.ws.rs.core.MediaType;
+
+import org.bitcoinj.core.Transaction;
+import org.qortal.api.ApiError;
+import org.qortal.api.ApiErrors;
+import org.qortal.api.ApiExceptionFactory;
+import org.qortal.api.Security;
+import org.qortal.api.model.crosschain.BitcoinSendRequest;
+import org.qortal.crosschain.Bitcoin;
+import org.qortal.crosschain.BitcoinyTransaction;
+import org.qortal.crosschain.ForeignBlockchainException;
+
+@Path("/crosschain/btc")
+@Tag(name = "Cross-Chain (Bitcoin)")
+public class CrossChainBitcoinResource {
+
+	@Context
+	HttpServletRequest request;
+
+	@POST
+	@Path("/walletbalance")
+	@Operation(
+		summary = "Returns BTC balance for hierarchical, deterministic BIP32 wallet",
+		description = "Supply BIP32 'm' private/public key in base58, starting with 'xprv'/'xpub' for mainnet, 'tprv'/'tpub' for testnet",
+		requestBody = @RequestBody(
+			required = true,
+			content = @Content(
+				mediaType = MediaType.TEXT_PLAIN,
+				schema = @Schema(
+					type = "string",
+					description = "BIP32 'm' private/public key in base58",
+					example = "tpubD6NzVbkrYhZ4XTPc4btCZ6SMgn8CxmWkj6VBVZ1tfcJfMq4UwAjZbG8U74gGSypL9XBYk2R2BLbDBe8pcEyBKM1edsGQEPKXNbEskZozeZc"
+				)
+			)
+		),
+		responses = {
+			@ApiResponse(
+				content = @Content(mediaType = MediaType.TEXT_PLAIN, schema = @Schema(type = "string", description = "balance (satoshis)"))
+			)
+		}
+	)
+	@ApiErrors({ApiError.INVALID_PRIVATE_KEY, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE})
+	public String getBitcoinWalletBalance(String key58) {
+		Security.checkApiCallAllowed(request);
+
+		Bitcoin bitcoin = Bitcoin.getInstance();
+
+		if (!bitcoin.isValidDeterministicKey(key58))
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_PRIVATE_KEY);
+
+		Long balance = bitcoin.getWalletBalance(key58);
+		if (balance == null)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE);
+
+		return balance.toString();
+	}
+
+	@POST
+	@Path("/wallettransactions")
+	@Operation(
+		summary = "Returns transactions for hierarchical, deterministic BIP32 wallet",
+		description = "Supply BIP32 'm' private/public key in base58, starting with 'xprv'/'xpub' for mainnet, 'tprv'/'tpub' for testnet",
+		requestBody = @RequestBody(
+			required = true,
+			content = @Content(
+				mediaType = MediaType.TEXT_PLAIN,
+				schema = @Schema(
+					type = "string",
+					description = "BIP32 'm' private/public key in base58",
+					example = "tpubD6NzVbkrYhZ4XTPc4btCZ6SMgn8CxmWkj6VBVZ1tfcJfMq4UwAjZbG8U74gGSypL9XBYk2R2BLbDBe8pcEyBKM1edsGQEPKXNbEskZozeZc"
+				)
+			)
+		),
+		responses = {
+			@ApiResponse(
+				content = @Content(array = @ArraySchema( schema = @Schema( implementation = BitcoinyTransaction.class ) ) )
+			)
+		}
+	)
+	@ApiErrors({ApiError.INVALID_PRIVATE_KEY, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE})
+	public List<BitcoinyTransaction> getBitcoinWalletTransactions(String key58) {
+		Security.checkApiCallAllowed(request);
+
+		Bitcoin bitcoin = Bitcoin.getInstance();
+
+		if (!bitcoin.isValidDeterministicKey(key58))
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_PRIVATE_KEY);
+
+		try {
+			return bitcoin.getWalletTransactions(key58);
+		} catch (ForeignBlockchainException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE);
+		}
+	}
+
+	@POST
+	@Path("/send")
+	@Operation(
+		summary = "Sends BTC from hierarchical, deterministic BIP32 wallet to specific address",
+		description = "Currently only supports 'legacy' P2PKH Bitcoin addresses. Supply BIP32 'm' private key in base58, starting with 'xprv' for mainnet, 'tprv' for testnet",
+		requestBody = @RequestBody(
+			required = true,
+			content = @Content(
+				mediaType = MediaType.APPLICATION_JSON,
+				schema = @Schema(
+					implementation = BitcoinSendRequest.class
+				)
+			)
+		),
+		responses = {
+			@ApiResponse(
+				content = @Content(mediaType = MediaType.TEXT_PLAIN, schema = @Schema(type = "string", description = "transaction hash"))
+			)
+		}
+	)
+	@ApiErrors({ApiError.INVALID_PRIVATE_KEY, ApiError.INVALID_CRITERIA, ApiError.INVALID_ADDRESS, ApiError.FOREIGN_BLOCKCHAIN_BALANCE_ISSUE, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE})
+	public String sendBitcoin(BitcoinSendRequest bitcoinSendRequest) {
+		Security.checkApiCallAllowed(request);
+
+		if (bitcoinSendRequest.bitcoinAmount <= 0)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+
+		if (bitcoinSendRequest.feePerByte != null && bitcoinSendRequest.feePerByte <= 0)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+
+		Bitcoin bitcoin = Bitcoin.getInstance();
+
+		if (!bitcoin.isValidAddress(bitcoinSendRequest.receivingAddress))
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_ADDRESS);
+
+		if (!bitcoin.isValidDeterministicKey(bitcoinSendRequest.xprv58))
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_PRIVATE_KEY);
+
+		Transaction spendTransaction = bitcoin.buildSpend(bitcoinSendRequest.xprv58,
+				bitcoinSendRequest.receivingAddress,
+				bitcoinSendRequest.bitcoinAmount,
+				bitcoinSendRequest.feePerByte);
+
+		if (spendTransaction == null)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_BALANCE_ISSUE);
+
+		try {
+			bitcoin.broadcastTransaction(spendTransaction);
+		} catch (ForeignBlockchainException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE);
+		}
+
+		return spendTransaction.getTxId().toString();
+	}
+
+}

src/main/java/org/qortal/api/resource/CrossChainHtlcResource.java

@@ -0,0 +1,175 @@
+package org.qortal.api.resource;
+
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.media.Content;
+import io.swagger.v3.oas.annotations.media.Schema;
+import io.swagger.v3.oas.annotations.responses.ApiResponse;
+import io.swagger.v3.oas.annotations.tags.Tag;
+
+import java.math.BigDecimal;
+import java.util.List;
+
+import javax.servlet.http.HttpServletRequest;
+import javax.ws.rs.GET;
+import javax.ws.rs.Path;
+import javax.ws.rs.PathParam;
+import javax.ws.rs.core.Context;
+import javax.ws.rs.core.MediaType;
+
+import org.bitcoinj.core.TransactionOutput;
+import org.qortal.api.ApiError;
+import org.qortal.api.ApiErrors;
+import org.qortal.api.ApiExceptionFactory;
+import org.qortal.api.Security;
+import org.qortal.api.model.CrossChainBitcoinyHTLCStatus;
+import org.qortal.crosschain.Bitcoiny;
+import org.qortal.crosschain.ForeignBlockchainException;
+import org.qortal.crosschain.SupportedBlockchain;
+import org.qortal.crosschain.BitcoinyHTLC;
+import org.qortal.utils.NTP;
+
+import com.google.common.hash.HashCode;
+
+@Path("/crosschain/htlc")
+@Tag(name = "Cross-Chain (Hash time-locked contracts)")
+public class CrossChainHtlcResource {
+
+	@Context
+	HttpServletRequest request;
+
+	@GET
+	@Path("/address/{blockchain}/{refundPKH}/{locktime}/{redeemPKH}/{hashOfSecret}")
+	@Operation(
+		summary = "Returns HTLC address based on trade info",
+		description = "Blockchain can be BITCOIN or LITECOIN. Public key hashes (PKH) and hash of secret should be 20 bytes (hex). Locktime is seconds since epoch.",
+		responses = {
+			@ApiResponse(
+				content = @Content(mediaType = MediaType.TEXT_PLAIN, schema = @Schema(type = "string"))
+			)
+		}
+	)
+	@ApiErrors({ApiError.INVALID_PUBLIC_KEY, ApiError.INVALID_CRITERIA})
+	public String deriveHtlcAddress(@PathParam("blockchain") String blockchainName,
+			@PathParam("refundPKH") String refundHex,
+			@PathParam("locktime") int lockTime,
+			@PathParam("redeemPKH") String redeemHex,
+			@PathParam("hashOfSecret") String hashOfSecretHex) {
+		SupportedBlockchain blockchain = SupportedBlockchain.valueOf(blockchainName);
+		if (blockchain == null)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+
+		byte[] refunderPubKeyHash;
+		byte[] redeemerPubKeyHash;
+		byte[] hashOfSecret;
+
+		try {
+			refunderPubKeyHash = HashCode.fromString(refundHex).asBytes();
+			redeemerPubKeyHash = HashCode.fromString(redeemHex).asBytes();
+
+			if (refunderPubKeyHash.length != 20 || redeemerPubKeyHash.length != 20)
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_PUBLIC_KEY);
+		} catch (IllegalArgumentException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_PUBLIC_KEY);
+		}
+
+		try {
+			hashOfSecret = HashCode.fromString(hashOfSecretHex).asBytes();
+			if (hashOfSecret.length != 20)
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+		} catch (IllegalArgumentException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+		}
+
+		byte[] redeemScript = BitcoinyHTLC.buildScript(refunderPubKeyHash, lockTime, redeemerPubKeyHash, hashOfSecret);
+
+		Bitcoiny bitcoiny = (Bitcoiny) blockchain.getInstance();
+
+		return bitcoiny.deriveP2shAddress(redeemScript);
+	}
+
+	@GET
+	@Path("/status/{blockchain}/{refundPKH}/{locktime}/{redeemPKH}/{hashOfSecret}")
+	@Operation(
+		summary = "Checks HTLC status",
+		description = "Blockchain can be BITCOIN or LITECOIN. Public key hashes (PKH) and hash of secret should be 20 bytes (hex). Locktime is seconds since epoch.",
+		responses = {
+			@ApiResponse(
+				content = @Content(mediaType = MediaType.APPLICATION_JSON, schema = @Schema(implementation = CrossChainBitcoinyHTLCStatus.class))
+			)
+		}
+	)
+	@ApiErrors({ApiError.INVALID_CRITERIA, ApiError.INVALID_ADDRESS, ApiError.ADDRESS_UNKNOWN})
+	public CrossChainBitcoinyHTLCStatus checkHtlcStatus(@PathParam("blockchain") String blockchainName,
+			@PathParam("refundPKH") String refundHex,
+			@PathParam("locktime") int lockTime,
+			@PathParam("redeemPKH") String redeemHex,
+			@PathParam("hashOfSecret") String hashOfSecretHex) {
+		Security.checkApiCallAllowed(request);
+
+		SupportedBlockchain blockchain = SupportedBlockchain.valueOf(blockchainName);
+		if (blockchain == null)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+
+		byte[] refunderPubKeyHash;
+		byte[] redeemerPubKeyHash;
+		byte[] hashOfSecret;
+
+		try {
+			refunderPubKeyHash = HashCode.fromString(refundHex).asBytes();
+			redeemerPubKeyHash = HashCode.fromString(redeemHex).asBytes();
+
+			if (refunderPubKeyHash.length != 20 || redeemerPubKeyHash.length != 20)
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_PUBLIC_KEY);
+		} catch (IllegalArgumentException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_PUBLIC_KEY);
+		}
+
+		try {
+			hashOfSecret = HashCode.fromString(hashOfSecretHex).asBytes();
+			if (hashOfSecret.length != 20)
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+		} catch (IllegalArgumentException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+		}
+
+		byte[] redeemScript = BitcoinyHTLC.buildScript(refunderPubKeyHash, lockTime, redeemerPubKeyHash, hashOfSecret);
+
+		Bitcoiny bitcoiny = (Bitcoiny) blockchain.getInstance();
+
+		String p2shAddress = bitcoiny.deriveP2shAddress(redeemScript);
+
+		long now = NTP.getTime();
+
+		try {
+			int medianBlockTime = bitcoiny.getMedianBlockTime();
+
+			// Check P2SH is funded
+			long p2shBalance = bitcoiny.getConfirmedBalance(p2shAddress.toString());
+
+			CrossChainBitcoinyHTLCStatus htlcStatus = new CrossChainBitcoinyHTLCStatus();
+			htlcStatus.bitcoinP2shAddress = p2shAddress;
+			htlcStatus.bitcoinP2shBalance = BigDecimal.valueOf(p2shBalance, 8);
+
+			List<TransactionOutput> fundingOutputs = bitcoiny.getUnspentOutputs(p2shAddress.toString());
+
+			if (p2shBalance > 0L && !fundingOutputs.isEmpty()) {
+				htlcStatus.canRedeem = now >= medianBlockTime * 1000L;
+				htlcStatus.canRefund = now >= lockTime * 1000L;
+			}
+
+			if (now >= medianBlockTime * 1000L) {
+				// See if we can extract secret
+				htlcStatus.secret = BitcoinyHTLC.findHtlcSecret(bitcoiny, htlcStatus.bitcoinP2shAddress);
+			}
+
+			return htlcStatus;
+		} catch (ForeignBlockchainException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE);
+		}
+	}
+
+	// TODO: refund
+
+	// TODO: redeem
+
+}

src/main/java/org/qortal/api/resource/CrossChainLitecoinResource.java

@@ -0,0 +1,167 @@
+package org.qortal.api.resource;
+
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.media.ArraySchema;
+import io.swagger.v3.oas.annotations.media.Content;
+import io.swagger.v3.oas.annotations.media.Schema;
+import io.swagger.v3.oas.annotations.parameters.RequestBody;
+import io.swagger.v3.oas.annotations.responses.ApiResponse;
+import io.swagger.v3.oas.annotations.tags.Tag;
+
+import java.util.List;
+
+import javax.servlet.http.HttpServletRequest;
+import javax.ws.rs.POST;
+import javax.ws.rs.Path;
+import javax.ws.rs.core.Context;
+import javax.ws.rs.core.MediaType;
+
+import org.bitcoinj.core.Transaction;
+import org.qortal.api.ApiError;
+import org.qortal.api.ApiErrors;
+import org.qortal.api.ApiExceptionFactory;
+import org.qortal.api.Security;
+import org.qortal.api.model.crosschain.LitecoinSendRequest;
+import org.qortal.crosschain.BitcoinyTransaction;
+import org.qortal.crosschain.ForeignBlockchainException;
+import org.qortal.crosschain.Litecoin;
+
+@Path("/crosschain/ltc")
+@Tag(name = "Cross-Chain (Litecoin)")
+public class CrossChainLitecoinResource {
+
+	@Context
+	HttpServletRequest request;
+
+	@POST
+	@Path("/walletbalance")
+	@Operation(
+		summary = "Returns LTC balance for hierarchical, deterministic BIP32 wallet",
+		description = "Supply BIP32 'm' private/public key in base58, starting with 'xprv'/'xpub' for mainnet, 'tprv'/'tpub' for testnet",
+		requestBody = @RequestBody(
+			required = true,
+			content = @Content(
+				mediaType = MediaType.TEXT_PLAIN,
+				schema = @Schema(
+					type = "string",
+					description = "BIP32 'm' private/public key in base58",
+					example = "tpubD6NzVbkrYhZ4XTPc4btCZ6SMgn8CxmWkj6VBVZ1tfcJfMq4UwAjZbG8U74gGSypL9XBYk2R2BLbDBe8pcEyBKM1edsGQEPKXNbEskZozeZc"
+				)
+			)
+		),
+		responses = {
+			@ApiResponse(
+				content = @Content(mediaType = MediaType.TEXT_PLAIN, schema = @Schema(type = "string", description = "balance (satoshis)"))
+			)
+		}
+	)
+	@ApiErrors({ApiError.INVALID_PRIVATE_KEY, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE})
+	public String getLitecoinWalletBalance(String key58) {
+		Security.checkApiCallAllowed(request);
+
+		Litecoin litecoin = Litecoin.getInstance();
+
+		if (!litecoin.isValidDeterministicKey(key58))
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_PRIVATE_KEY);
+
+		Long balance = litecoin.getWalletBalance(key58);
+		if (balance == null)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE);
+
+		return balance.toString();
+	}
+
+	@POST
+	@Path("/wallettransactions")
+	@Operation(
+		summary = "Returns transactions for hierarchical, deterministic BIP32 wallet",
+		description = "Supply BIP32 'm' private/public key in base58, starting with 'xprv'/'xpub' for mainnet, 'tprv'/'tpub' for testnet",
+		requestBody = @RequestBody(
+			required = true,
+			content = @Content(
+				mediaType = MediaType.TEXT_PLAIN,
+				schema = @Schema(
+					type = "string",
+					description = "BIP32 'm' private/public key in base58",
+					example = "tpubD6NzVbkrYhZ4XTPc4btCZ6SMgn8CxmWkj6VBVZ1tfcJfMq4UwAjZbG8U74gGSypL9XBYk2R2BLbDBe8pcEyBKM1edsGQEPKXNbEskZozeZc"
+				)
+			)
+		),
+		responses = {
+			@ApiResponse(
+				content = @Content(array = @ArraySchema( schema = @Schema( implementation = BitcoinyTransaction.class ) ) )
+			)
+		}
+	)
+	@ApiErrors({ApiError.INVALID_PRIVATE_KEY, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE})
+	public List<BitcoinyTransaction> getLitecoinWalletTransactions(String key58) {
+		Security.checkApiCallAllowed(request);
+
+		Litecoin litecoin = Litecoin.getInstance();
+
+		if (!litecoin.isValidDeterministicKey(key58))
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_PRIVATE_KEY);
+
+		try {
+			return litecoin.getWalletTransactions(key58);
+		} catch (ForeignBlockchainException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE);
+		}
+	}
+
+	@POST
+	@Path("/send")
+	@Operation(
+		summary = "Sends LTC from hierarchical, deterministic BIP32 wallet to specific address",
+		description = "Currently only supports 'legacy' P2PKH Litecoin addresses. Supply BIP32 'm' private key in base58, starting with 'xprv' for mainnet, 'tprv' for testnet",
+		requestBody = @RequestBody(
+			required = true,
+			content = @Content(
+				mediaType = MediaType.APPLICATION_JSON,
+				schema = @Schema(
+					implementation = LitecoinSendRequest.class
+				)
+			)
+		),
+		responses = {
+			@ApiResponse(
+				content = @Content(mediaType = MediaType.TEXT_PLAIN, schema = @Schema(type = "string", description = "transaction hash"))
+			)
+		}
+	)
+	@ApiErrors({ApiError.INVALID_PRIVATE_KEY, ApiError.INVALID_CRITERIA, ApiError.INVALID_ADDRESS, ApiError.FOREIGN_BLOCKCHAIN_BALANCE_ISSUE, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE})
+	public String sendBitcoin(LitecoinSendRequest litecoinSendRequest) {
+		Security.checkApiCallAllowed(request);
+
+		if (litecoinSendRequest.litecoinAmount <= 0)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+
+		if (litecoinSendRequest.feePerByte != null && litecoinSendRequest.feePerByte <= 0)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+
+		Litecoin litecoin = Litecoin.getInstance();
+
+		if (!litecoin.isValidAddress(litecoinSendRequest.receivingAddress))
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_ADDRESS);
+
+		if (!litecoin.isValidDeterministicKey(litecoinSendRequest.xprv58))
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_PRIVATE_KEY);
+
+		Transaction spendTransaction = litecoin.buildSpend(litecoinSendRequest.xprv58,
+				litecoinSendRequest.receivingAddress,
+				litecoinSendRequest.litecoinAmount,
+				litecoinSendRequest.feePerByte);
+
+		if (spendTransaction == null)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_BALANCE_ISSUE);
+
+		try {
+			litecoin.broadcastTransaction(spendTransaction);
+		} catch (ForeignBlockchainException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE);
+		}
+
+		return spendTransaction.getTxId().toString();
+	}
+
+}

src/main/java/org/qortal/api/resource/CrossChainTradeBotResource.java

@@ -0,0 +1,286 @@
+package org.qortal.api.resource;
+
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.Parameter;
+import io.swagger.v3.oas.annotations.media.ArraySchema;
+import io.swagger.v3.oas.annotations.media.Content;
+import io.swagger.v3.oas.annotations.media.Schema;
+import io.swagger.v3.oas.annotations.parameters.RequestBody;
+import io.swagger.v3.oas.annotations.responses.ApiResponse;
+import io.swagger.v3.oas.annotations.tags.Tag;
+
+import java.util.List;
+import java.util.stream.Collectors;
+
+import javax.servlet.http.HttpServletRequest;
+import javax.ws.rs.DELETE;
+import javax.ws.rs.GET;
+import javax.ws.rs.POST;
+import javax.ws.rs.Path;
+import javax.ws.rs.QueryParam;
+import javax.ws.rs.core.Context;
+import javax.ws.rs.core.MediaType;
+
+import org.qortal.account.Account;
+import org.qortal.account.PublicKeyAccount;
+import org.qortal.api.ApiError;
+import org.qortal.api.ApiErrors;
+import org.qortal.api.ApiExceptionFactory;
+import org.qortal.api.Security;
+import org.qortal.api.model.crosschain.TradeBotCreateRequest;
+import org.qortal.api.model.crosschain.TradeBotRespondRequest;
+import org.qortal.asset.Asset;
+import org.qortal.controller.tradebot.AcctTradeBot;
+import org.qortal.controller.tradebot.TradeBot;
+import org.qortal.crosschain.ForeignBlockchain;
+import org.qortal.crosschain.SupportedBlockchain;
+import org.qortal.crosschain.ACCT;
+import org.qortal.crosschain.AcctMode;
+import org.qortal.crypto.Crypto;
+import org.qortal.data.at.ATData;
+import org.qortal.data.crosschain.CrossChainTradeData;
+import org.qortal.data.crosschain.TradeBotData;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.repository.RepositoryManager;
+import org.qortal.utils.Base58;
+
+@Path("/crosschain/tradebot")
+@Tag(name = "Cross-Chain (Trade-Bot)")
+public class CrossChainTradeBotResource {
+
+	@Context
+	HttpServletRequest request;
+
+	@GET
+	@Operation(
+		summary = "List current trade-bot states",
+		responses = {
+			@ApiResponse(
+				content = @Content(
+					array = @ArraySchema(
+						schema = @Schema(
+							implementation = TradeBotData.class
+						)
+					)
+				)
+			)
+		}
+	)
+	@ApiErrors({ApiError.REPOSITORY_ISSUE})
+	public List<TradeBotData> getTradeBotStates(
+			@Parameter(
+					description = "Limit to specific blockchain",
+					example = "LITECOIN",
+					schema = @Schema(implementation = SupportedBlockchain.class)
+				) @QueryParam("foreignBlockchain") SupportedBlockchain foreignBlockchain) {
+		Security.checkApiCallAllowed(request);
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			List<TradeBotData> allTradeBotData = repository.getCrossChainRepository().getAllTradeBotData();
+
+			if (foreignBlockchain == null)
+				return allTradeBotData;
+
+			return allTradeBotData.stream().filter(tradeBotData -> tradeBotData.getForeignBlockchain().equals(foreignBlockchain.name())).collect(Collectors.toList());
+		} catch (DataException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
+		}
+	}
+
+	@POST
+	@Path("/create")
+	@Operation(
+		summary = "Create a trade offer (trade-bot entry)",
+		requestBody = @RequestBody(
+			required = true,
+			content = @Content(
+				mediaType = MediaType.APPLICATION_JSON,
+				schema = @Schema(
+					implementation = TradeBotCreateRequest.class
+				)
+			)
+		),
+		responses = {
+			@ApiResponse(
+				content = @Content(mediaType = MediaType.TEXT_PLAIN, schema = @Schema(type = "string"))
+			)
+		}
+	)
+	@ApiErrors({ApiError.INVALID_PUBLIC_KEY, ApiError.INVALID_ADDRESS, ApiError.INVALID_CRITERIA, ApiError.INSUFFICIENT_BALANCE, ApiError.REPOSITORY_ISSUE})
+	@SuppressWarnings("deprecation")
+	public String tradeBotCreator(TradeBotCreateRequest tradeBotCreateRequest) {
+		Security.checkApiCallAllowed(request);
+
+		if (tradeBotCreateRequest.foreignBlockchain == null)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+
+		ForeignBlockchain foreignBlockchain = tradeBotCreateRequest.foreignBlockchain.getInstance();
+
+		// We prefer foreignAmount to deprecated bitcoinAmount
+		if (tradeBotCreateRequest.foreignAmount == null)
+			tradeBotCreateRequest.foreignAmount = tradeBotCreateRequest.bitcoinAmount;
+
+		if (!foreignBlockchain.isValidAddress(tradeBotCreateRequest.receivingAddress))
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_ADDRESS);
+
+		if (tradeBotCreateRequest.tradeTimeout < 60)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+
+		if (tradeBotCreateRequest.foreignAmount == null || tradeBotCreateRequest.foreignAmount <= 0)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+
+		if (tradeBotCreateRequest.qortAmount <= 0 || tradeBotCreateRequest.fundingQortAmount <= 0)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			// Do some simple checking first
+			Account creator = new PublicKeyAccount(repository, tradeBotCreateRequest.creatorPublicKey);
+
+			if (creator.getConfirmedBalance(Asset.QORT) < tradeBotCreateRequest.fundingQortAmount)
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INSUFFICIENT_BALANCE);
+
+			byte[] unsignedBytes = TradeBot.getInstance().createTrade(repository, tradeBotCreateRequest);
+			if (unsignedBytes == null)
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+
+			return Base58.encode(unsignedBytes);
+		} catch (DataException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
+		}
+	}
+
+	@POST
+	@Path("/respond")
+	@Operation(
+		summary = "Respond to a trade offer. NOTE: WILL SPEND FUNDS!)",
+		description = "Start a new trade-bot entry to respond to chosen trade offer.",
+		requestBody = @RequestBody(
+			required = true,
+			content = @Content(
+				mediaType = MediaType.APPLICATION_JSON,
+				schema = @Schema(
+					implementation = TradeBotRespondRequest.class
+				)
+			)
+		),
+		responses = {
+			@ApiResponse(
+				content = @Content(mediaType = MediaType.TEXT_PLAIN, schema = @Schema(type = "string"))
+			)
+		}
+	)
+	@ApiErrors({ApiError.INVALID_PRIVATE_KEY, ApiError.INVALID_ADDRESS, ApiError.INVALID_CRITERIA, ApiError.FOREIGN_BLOCKCHAIN_BALANCE_ISSUE, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE, ApiError.REPOSITORY_ISSUE})
+	@SuppressWarnings("deprecation")
+	public String tradeBotResponder(TradeBotRespondRequest tradeBotRespondRequest) {
+		Security.checkApiCallAllowed(request);
+
+		final String atAddress = tradeBotRespondRequest.atAddress;
+
+		// We prefer foreignKey to deprecated xprv58
+		if (tradeBotRespondRequest.foreignKey == null)
+			tradeBotRespondRequest.foreignKey = tradeBotRespondRequest.xprv58;
+
+		if (tradeBotRespondRequest.foreignKey == null)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_PRIVATE_KEY);
+
+		if (atAddress == null || !Crypto.isValidAtAddress(atAddress))
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_ADDRESS);
+
+		if (tradeBotRespondRequest.receivingAddress == null || !Crypto.isValidAddress(tradeBotRespondRequest.receivingAddress))
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_ADDRESS);
+
+		// Extract data from cross-chain trading AT
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			ATData atData = fetchAtDataWithChecking(repository, atAddress);
+
+			// TradeBot uses AT's code hash to map to ACCT
+			ACCT acct = TradeBot.getInstance().getAcctUsingAtData(atData);
+			if (acct == null)
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_ADDRESS);
+
+			if (!acct.getBlockchain().isValidWalletKey(tradeBotRespondRequest.foreignKey))
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_PRIVATE_KEY);
+
+			CrossChainTradeData crossChainTradeData = acct.populateTradeData(repository, atData);
+			if (crossChainTradeData == null)
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_ADDRESS);
+
+			if (crossChainTradeData.mode != AcctMode.OFFERING)
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+
+			AcctTradeBot.ResponseResult result = TradeBot.getInstance().startResponse(repository, atData, acct, crossChainTradeData,
+					tradeBotRespondRequest.foreignKey, tradeBotRespondRequest.receivingAddress);
+
+			switch (result) {
+				case OK:
+					return "true";
+
+				case BALANCE_ISSUE:
+					throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_BALANCE_ISSUE);
+
+				case NETWORK_ISSUE:
+					throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE);
+
+				default:
+					return "false";
+			}
+		} catch (DataException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
+		}
+	}
+
+	@DELETE
+	@Operation(
+		summary = "Delete completed trade",
+		requestBody = @RequestBody(
+			required = true,
+			content = @Content(
+				mediaType = MediaType.TEXT_PLAIN,
+				schema = @Schema(
+					type = "string",
+					example = "93MB2qRDNVLxbmmPuYpLdAqn3u2x9ZhaVZK5wELHueP8"
+				)
+			)
+		),
+		responses = {
+			@ApiResponse(
+				content = @Content(mediaType = MediaType.TEXT_PLAIN, schema = @Schema(type = "string"))
+			)
+		}
+	)
+	@ApiErrors({ApiError.INVALID_ADDRESS, ApiError.REPOSITORY_ISSUE})
+	public String tradeBotDelete(String tradePrivateKey58) {
+		Security.checkApiCallAllowed(request);
+
+		final byte[] tradePrivateKey;
+		try {
+			tradePrivateKey = Base58.decode(tradePrivateKey58);
+
+			if (tradePrivateKey.length != 32)
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_PRIVATE_KEY);
+		} catch (NumberFormatException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_PRIVATE_KEY);
+		}
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			// Handed off to TradeBot
+			return TradeBot.getInstance().deleteEntry(repository, tradePrivateKey) ? "true" : "false";
+		} catch (DataException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
+		}
+	}
+
+	private ATData fetchAtDataWithChecking(Repository repository, String atAddress) throws DataException {
+		ATData atData = repository.getATRepository().fromATAddress(atAddress);
+		if (atData == null)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.ADDRESS_UNKNOWN);
+
+		// No point sending message to AT that's finished
+		if (atData.getIsFinished())
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+
+		return atData;
+	}
+
+}

src/main/java/org/qortal/api/resource/TransactionsResource.java

@@ -510,14 +510,19 @@ public class TransactionsResource {
 		if (!Controller.getInstance().isUpToDate())
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.BLOCKCHAIN_NEEDS_SYNC);
 
+		byte[] rawBytes = Base58.decode(rawBytes58);
+
+		TransactionData transactionData;
+		try {
+			transactionData = TransactionTransformer.fromBytes(rawBytes);
+		} catch (TransformationException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.TRANSFORMATION_ERROR, e);
+		}
+
+		if (transactionData == null)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_DATA);
+
 		try (final Repository repository = RepositoryManager.getRepository()) {
-			byte[] rawBytes = Base58.decode(rawBytes58);
-
-			TransactionData transactionData = TransactionTransformer.fromBytes(rawBytes);
-
-			if (transactionData == null)
-				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_DATA);
-
 			Transaction transaction = Transaction.fromData(repository, transactionData);
 
 			if (!transaction.isSignatureValid())
@@ -535,16 +540,9 @@ public class TransactionsResource {
 				blockchainLock.unlock();
 			}
 
-			// Notify controller of new transaction
-			Controller.getInstance().onNewTransaction(transactionData, null);
-
 			return "true";
 		} catch (NumberFormatException e) {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_DATA, e);
-		} catch (TransformationException e) {
-			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.TRANSFORMATION_ERROR, e);
-		} catch (ApiException e) {
-			throw e;
 		} catch (DataException e) {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
 		} catch (InterruptedException e) {

src/main/java/org/qortal/api/websocket/ApiWebSocket.java

@@ -107,7 +107,9 @@ abstract class ApiWebSocket extends WebSocketServlet {
 
 	public void onWebSocketClose(Session session, int statusCode, String reason) {
 		synchronized (SESSIONS_BY_CLASS) {
-			SESSIONS_BY_CLASS.get(this.getClass()).remove(session);
+			List<Session> sessions = SESSIONS_BY_CLASS.get(this.getClass());
+			if (sessions != null)
+				sessions.remove(session);
 		}
 	}
 

src/main/java/org/qortal/api/websocket/PresenceWebSocket.java

@@ -0,0 +1,244 @@
+package org.qortal.api.websocket;
+
+import java.io.IOException;
+import java.io.StringWriter;
+import java.util.Collections;
+import java.util.EnumMap;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+import javax.xml.bind.annotation.XmlAccessType;
+import javax.xml.bind.annotation.XmlAccessorType;
+
+import org.eclipse.jetty.websocket.api.Session;
+import org.eclipse.jetty.websocket.api.annotations.OnWebSocketClose;
+import org.eclipse.jetty.websocket.api.annotations.OnWebSocketConnect;
+import org.eclipse.jetty.websocket.api.annotations.OnWebSocketError;
+import org.eclipse.jetty.websocket.api.annotations.OnWebSocketMessage;
+import org.eclipse.jetty.websocket.api.annotations.WebSocket;
+import org.eclipse.jetty.websocket.servlet.WebSocketServletFactory;
+import org.qortal.controller.Controller;
+import org.qortal.crypto.Crypto;
+import org.qortal.data.transaction.PresenceTransactionData;
+import org.qortal.data.transaction.TransactionData;
+import org.qortal.event.Event;
+import org.qortal.event.EventBus;
+import org.qortal.event.Listener;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.repository.RepositoryManager;
+import org.qortal.transaction.PresenceTransaction.PresenceType;
+import org.qortal.transaction.Transaction.TransactionType;
+import org.qortal.utils.Base58;
+import org.qortal.utils.NTP;
+
+@WebSocket
+@SuppressWarnings("serial")
+public class PresenceWebSocket extends ApiWebSocket implements Listener {
+
+	@XmlAccessorType(XmlAccessType.FIELD)
+	@SuppressWarnings("unused")
+	private static class PresenceInfo {
+		private final PresenceType presenceType;
+		private final String publicKey;
+		private final long timestamp;
+		private final String address;
+
+		protected PresenceInfo() {
+			this.presenceType = null;
+			this.publicKey = null;
+			this.timestamp = 0L;
+			this.address = null;
+		}
+
+		public PresenceInfo(PresenceType presenceType, String pubKey58, long timestamp) {
+			this.presenceType = presenceType;
+			this.publicKey = pubKey58;
+			this.timestamp = timestamp;
+			this.address = Crypto.toAddress(Base58.decode(this.publicKey));
+		}
+
+		public PresenceType getPresenceType() {
+			return this.presenceType;
+		}
+
+		public String getPublicKey() {
+			return this.publicKey;
+		}
+
+		public long getTimestamp() {
+			return this.timestamp;
+		}
+
+		public String getAddress() {
+			return this.address;
+		}
+	}
+
+	/** Outer map key is PresenceType (enum), inner map key is public key in base58, inner map value is timestamp */
+	private static final Map<PresenceType, Map<String, Long>> currentEntries = Collections.synchronizedMap(new EnumMap<>(PresenceType.class));
+
+	/** (Optional) PresenceType used for filtering by that Session. */
+	private static final Map<Session, PresenceType> sessionPresenceTypes = Collections.synchronizedMap(new HashMap<>());
+
+	@Override
+	public void configure(WebSocketServletFactory factory) {
+		factory.register(PresenceWebSocket.class);
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			populateCurrentInfo(repository);
+		} catch (DataException e) {
+			// How to fail properly?
+			return;
+		}
+
+		EventBus.INSTANCE.addListener(this::listen);
+	}
+
+	@Override
+	public void listen(Event event) {
+		// We use NewBlockEvent as a proxy for 1-minute timer
+		if (!(event instanceof Controller.NewTransactionEvent) && !(event instanceof Controller.NewBlockEvent))
+			return;
+
+		removeOldEntries();
+
+		if (event instanceof Controller.NewBlockEvent)
+			// We only wanted a chance to cull old entries
+			return;
+
+		TransactionData transactionData = ((Controller.NewTransactionEvent) event).getTransactionData();
+
+		if (transactionData.getType() != TransactionType.PRESENCE)
+			return;
+
+		PresenceTransactionData presenceData = (PresenceTransactionData) transactionData;
+		PresenceType presenceType = presenceData.getPresenceType();
+
+		// Put/replace for this publickey making sure we keep newest timestamp
+		String pubKey58 = Base58.encode(presenceData.getCreatorPublicKey());
+		long ourTimestamp = presenceData.getTimestamp();
+		long computedTimestamp = mergePresence(presenceType, pubKey58, ourTimestamp);
+
+		if (computedTimestamp != ourTimestamp)
+			// nothing changed
+			return;
+
+		List<PresenceInfo> presenceInfo = Collections.singletonList(new PresenceInfo(presenceType, pubKey58, computedTimestamp));
+
+		// Notify sessions
+		for (Session session : getSessions()) {
+			PresenceType sessionPresenceType = sessionPresenceTypes.get(session);
+
+			if (sessionPresenceType == null || sessionPresenceType == presenceType)
+				sendPresenceInfo(session, presenceInfo);
+		}
+	}
+
+	@OnWebSocketConnect
+	@Override
+	public void onWebSocketConnect(Session session) {
+		Map<String, List<String>> queryParams = session.getUpgradeRequest().getParameterMap();
+		List<String> presenceTypes = queryParams.get("presenceType");
+
+		// We only support ONE presenceType
+		String presenceTypeName = presenceTypes == null || presenceTypes.isEmpty() ? null : presenceTypes.get(0);
+
+		PresenceType presenceType = presenceTypeName == null ? null : PresenceType.fromString(presenceTypeName);
+
+		// Make sure that if caller does give a presenceType, that it is a valid/known one.
+		if (presenceTypeName != null && presenceType == null) {
+			session.close(4003, "unknown presenceType: " + presenceTypeName);
+			return;
+		}
+
+		// Save session's requested PresenceType, if given
+		if (presenceType != null)
+			sessionPresenceTypes.put(session, presenceType);
+
+		List<PresenceInfo> presenceInfo;
+
+		synchronized (currentEntries) {
+			presenceInfo = currentEntries.entrySet().stream()
+					.filter(entry -> presenceType == null ? true : entry.getKey() == presenceType)
+					.flatMap(entry -> entry.getValue().entrySet().stream().map(innerEntry -> new PresenceInfo(entry.getKey(), innerEntry.getKey(), innerEntry.getValue())))
+					.collect(Collectors.toList());
+		}
+
+		if (!sendPresenceInfo(session, presenceInfo)) {
+			session.close(4002, "websocket issue");
+			return;
+		}
+
+		super.onWebSocketConnect(session);
+	}
+
+	@OnWebSocketClose
+	@Override
+	public void onWebSocketClose(Session session, int statusCode, String reason) {
+		// clean up
+		sessionPresenceTypes.remove(session);
+
+		super.onWebSocketClose(session, statusCode, reason);
+	}
+
+	@OnWebSocketError
+	public void onWebSocketError(Session session, Throwable throwable) {
+		/* ignored */
+	}
+
+	@OnWebSocketMessage
+	public void onWebSocketMessage(Session session, String message) {
+		/* ignored */
+	}
+
+	private boolean sendPresenceInfo(Session session, List<PresenceInfo> presenceInfo) {
+		try {
+			StringWriter stringWriter = new StringWriter();
+			marshall(stringWriter, presenceInfo);
+
+			String output = stringWriter.toString();
+			session.getRemote().sendStringByFuture(output);
+		} catch (IOException e) {
+			// No output this time?
+			return false;
+		}
+
+		return true;
+	}
+
+	private static void populateCurrentInfo(Repository repository) throws DataException {
+		// We want ALL PRESENCE transactions
+
+		List<TransactionData> presenceTransactionsData = repository.getTransactionRepository().getUnconfirmedTransactions(TransactionType.PRESENCE, null);
+
+		for (TransactionData transactionData : presenceTransactionsData) {
+			PresenceTransactionData presenceData = (PresenceTransactionData) transactionData;
+
+			PresenceType presenceType = presenceData.getPresenceType();
+
+			// Put/replace for this publickey making sure we keep newest timestamp
+			String pubKey58 = Base58.encode(presenceData.getCreatorPublicKey());
+			long ourTimestamp = presenceData.getTimestamp();
+
+			mergePresence(presenceType, pubKey58, ourTimestamp);
+		}
+	}
+
+	private static long mergePresence(PresenceType presenceType, String pubKey58, long ourTimestamp) {
+		Map<String, Long> typedPubkeyTimestamps = currentEntries.computeIfAbsent(presenceType, someType -> Collections.synchronizedMap(new HashMap<>()));
+		return typedPubkeyTimestamps.compute(pubKey58, (somePubKey58, currentTimestamp) -> (currentTimestamp == null || currentTimestamp < ourTimestamp) ? ourTimestamp : currentTimestamp);
+	}
+
+	private static void removeOldEntries() {
+		long now = NTP.getTime();
+
+		currentEntries.entrySet().forEach(entry -> {
+			long expiryThreshold = now - entry.getKey().getLifetime();
+			entry.getValue().entrySet().removeIf(pubkeyTimestamp -> pubkeyTimestamp.getValue() < expiryThreshold);
+		});
+	}
+
+}

src/main/java/org/qortal/api/websocket/TradeBotWebSocket.java

@@ -15,7 +15,8 @@ import org.eclipse.jetty.websocket.api.annotations.OnWebSocketError;
 import org.eclipse.jetty.websocket.api.annotations.OnWebSocketMessage;
 import org.eclipse.jetty.websocket.api.annotations.WebSocket;
 import org.eclipse.jetty.websocket.servlet.WebSocketServletFactory;
-import org.qortal.controller.TradeBot;
+import org.qortal.controller.tradebot.TradeBot;
+import org.qortal.crosschain.SupportedBlockchain;
 import org.qortal.data.crosschain.TradeBotData;
 import org.qortal.event.Event;
 import org.qortal.event.EventBus;
@@ -30,7 +31,9 @@ import org.qortal.utils.Base58;
 public class TradeBotWebSocket extends ApiWebSocket implements Listener {
 
 	/** Cache of trade-bot entry states, keyed by trade-bot entry's "trade private key" (base58) */
-	private static final Map<String, TradeBotData.State> PREVIOUS_STATES = new HashMap<>();
+	private static final Map<String, Integer> PREVIOUS_STATES = new HashMap<>();
+
+	private static final Map<Session, String> sessionBlockchain = Collections.synchronizedMap(new HashMap<>());
 
 	@Override
 	public void configure(WebSocketServletFactory factory) {
@@ -42,7 +45,7 @@ public class TradeBotWebSocket extends ApiWebSocket implements Listener {
 				// How do we properly fail here?
 				return;
 
-			PREVIOUS_STATES.putAll(tradeBotEntries.stream().collect(Collectors.toMap(entry -> Base58.encode(entry.getTradePrivateKey()), TradeBotData::getState)));
+			PREVIOUS_STATES.putAll(tradeBotEntries.stream().collect(Collectors.toMap(entry -> Base58.encode(entry.getTradePrivateKey()), TradeBotData::getStateValue)));
 		} catch (DataException e) {
 			// No output this time
 		}
@@ -59,35 +62,59 @@ public class TradeBotWebSocket extends ApiWebSocket implements Listener {
 		String tradePrivateKey58 = Base58.encode(tradeBotData.getTradePrivateKey());
 
 		synchronized (PREVIOUS_STATES) {
-			if (PREVIOUS_STATES.get(tradePrivateKey58) == tradeBotData.getState())
+			Integer previousStateValue = PREVIOUS_STATES.get(tradePrivateKey58);
+			if (previousStateValue != null && previousStateValue == tradeBotData.getStateValue())
 				// Not changed
 				return;
 
-			PREVIOUS_STATES.put(tradePrivateKey58, tradeBotData.getState());
+			PREVIOUS_STATES.put(tradePrivateKey58, tradeBotData.getStateValue());
 		}
 
 		List<TradeBotData> tradeBotEntries = Collections.singletonList(tradeBotData);
-		for (Session session : getSessions())
-			sendEntries(session, tradeBotEntries);
+
+		for (Session session : getSessions()) {
+			// Only send if this session has this/no preferred blockchain
+			String preferredBlockchain = sessionBlockchain.get(session);
+
+			if (preferredBlockchain == null || preferredBlockchain.equals(tradeBotData.getForeignBlockchain()))
+				sendEntries(session, tradeBotEntries);
+		}
 	}
 
 	@OnWebSocketConnect
 	@Override
 	public void onWebSocketConnect(Session session) {
+		Map<String, List<String>> queryParams = session.getUpgradeRequest().getParameterMap();
+
+		List<String> foreignBlockchains = queryParams.get("foreignBlockchain");
+		final String foreignBlockchain = foreignBlockchains == null ? null : foreignBlockchains.get(0);
+
+		// Make sure blockchain (if any) is valid
+		if (foreignBlockchain != null && SupportedBlockchain.fromString(foreignBlockchain) == null) {
+			session.close(4003, "unknown blockchain: " + foreignBlockchain);
+			return;
+		}
+
+		// save session's preferred blockchain (if any)
+		sessionBlockchain.put(session, foreignBlockchain);
+
 		// Send all known trade-bot entries
 		try (final Repository repository = RepositoryManager.getRepository()) {
 			List<TradeBotData> tradeBotEntries = repository.getCrossChainRepository().getAllTradeBotData();
-			if (tradeBotEntries == null) {
-				session.close(4001, "repository issue fetching trade-bot entries");
-				return;
-			}
+
+			// Optional filtering
+			if (foreignBlockchain != null)
+				tradeBotEntries = tradeBotEntries.stream()
+						.filter(tradeBotData -> tradeBotData.getForeignBlockchain().equals(foreignBlockchain))
+						.collect(Collectors.toList());
 
 			if (!sendEntries(session, tradeBotEntries)) {
 				session.close(4002, "websocket issue");
 				return;
 			}
 		} catch (DataException e) {
-			// No output this time
+			session.close(4001, "repository issue fetching trade-bot entries");
+			return;
 		}
 
 		super.onWebSocketConnect(session);
@@ -96,6 +123,9 @@ public class TradeBotWebSocket extends ApiWebSocket implements Listener {
 	@OnWebSocketClose
 	@Override
 	public void onWebSocketClose(Session session, int statusCode, String reason) {
+		// clean up
+		sessionBlockchain.remove(session);
+
 		super.onWebSocketClose(session, statusCode, reason);
 	}
 

src/main/java/org/qortal/api/websocket/TradeOffersWebSocket.java

@@ -3,10 +3,13 @@ package org.qortal.api.websocket;
 import java.io.IOException;
 import java.io.StringWriter;
 import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.function.Predicate;
+import java.util.function.Supplier;
 import java.util.stream.Collectors;
 
 import org.apache.logging.log4j.LogManager;
@@ -20,7 +23,9 @@ import org.eclipse.jetty.websocket.api.annotations.WebSocket;
 import org.eclipse.jetty.websocket.servlet.WebSocketServletFactory;
 import org.qortal.api.model.CrossChainOfferSummary;
 import org.qortal.controller.Controller;
-import org.qortal.crosschain.BTCACCT;
+import org.qortal.crosschain.SupportedBlockchain;
+import org.qortal.crosschain.ACCT;
+import org.qortal.crosschain.AcctMode;
 import org.qortal.data.at.ATStateData;
 import org.qortal.data.block.BlockData;
 import org.qortal.data.crosschain.CrossChainTradeData;
@@ -30,6 +35,7 @@ import org.qortal.event.Listener;
 import org.qortal.repository.DataException;
 import org.qortal.repository.Repository;
 import org.qortal.repository.RepositoryManager;
+import org.qortal.utils.ByteArray;
 import org.qortal.utils.NTP;
 
 @WebSocket
@@ -38,18 +44,23 @@ public class TradeOffersWebSocket extends ApiWebSocket implements Listener {
 
 	private static final Logger LOGGER = LogManager.getLogger(TradeOffersWebSocket.class);
 
-	private static final Map<String, BTCACCT.Mode> previousAtModes = new HashMap<>();
+	private static class CachedOfferInfo {
+		public final Map<String, AcctMode> previousAtModes = new HashMap<>();
 
-	// OFFERING
-	private static final Map<String, CrossChainOfferSummary> currentSummaries = new HashMap<>();
-	// REDEEMED/REFUNDED/CANCELLED
-	private static final Map<String, CrossChainOfferSummary> historicSummaries = new HashMap<>();
+		// OFFERING
+		public final Map<String, CrossChainOfferSummary> currentSummaries = new HashMap<>();
+		// REDEEMED/REFUNDED/CANCELLED
+		public final Map<String, CrossChainOfferSummary> historicSummaries = new HashMap<>();
+	}
+	// Manual synchronization
+	private static final Map<String, CachedOfferInfo> cachedInfoByBlockchain = new HashMap<>();
 
 	private static final Predicate<CrossChainOfferSummary> isHistoric = offerSummary
-			-> offerSummary.getMode() == BTCACCT.Mode.REDEEMED
-			|| offerSummary.getMode() == BTCACCT.Mode.REFUNDED
-			|| offerSummary.getMode() == BTCACCT.Mode.CANCELLED;
+			-> offerSummary.getMode() == AcctMode.REDEEMED
+			|| offerSummary.getMode() == AcctMode.REFUNDED
+			|| offerSummary.getMode() == AcctMode.CANCELLED;
 
+	private static final Map<Session, String> sessionBlockchain = Collections.synchronizedMap(new HashMap<>());
 
 	@Override
 	public void configure(WebSocketServletFactory factory) {
@@ -75,7 +86,6 @@ public class TradeOffersWebSocket extends ApiWebSocket implements Listener {
 		BlockData blockData = ((Controller.NewBlockEvent) event).getBlockData();
 
 		// Process any new info
-		List<CrossChainOfferSummary> crossChainOfferSummaries;
 
 		try (final Repository repository = RepositoryManager.getRepository()) {
 			// Find any new/changed trade ATs since this block
@@ -84,60 +94,77 @@ public class TradeOffersWebSocket extends ApiWebSocket implements Listener {
 			final Long expectedValue = null;
 			final Integer minimumFinalHeight = blockData.getHeight();
 
-			List<ATStateData> atStates = repository.getATRepository().getMatchingFinalATStates(BTCACCT.CODE_BYTES_HASH,
-					isFinished, dataByteOffset, expectedValue, minimumFinalHeight,
-					null, null, null);
+			for (SupportedBlockchain blockchain : SupportedBlockchain.values()) {
+				Map<ByteArray, Supplier<ACCT>> acctsByCodeHash = SupportedBlockchain.getFilteredAcctMap(blockchain);
 
-			if (atStates == null)
-				return;
+				List<CrossChainOfferSummary> crossChainOfferSummaries = new ArrayList<>();
 
-			crossChainOfferSummaries = produceSummaries(repository, atStates, blockData.getTimestamp());
+				synchronized (cachedInfoByBlockchain) {
+					CachedOfferInfo cachedInfo = cachedInfoByBlockchain.computeIfAbsent(blockchain.name(), k -> new CachedOfferInfo());
+
+					for (Map.Entry<ByteArray, Supplier<ACCT>> acctInfo : acctsByCodeHash.entrySet()) {
+						byte[] codeHash = acctInfo.getKey().value;
+						ACCT acct = acctInfo.getValue().get();
+
+						List<ATStateData> atStates = repository.getATRepository().getMatchingFinalATStates(codeHash,
+								isFinished, dataByteOffset, expectedValue, minimumFinalHeight,
+								null, null, null);
+
+						crossChainOfferSummaries.addAll(produceSummaries(repository, acct, atStates, blockData.getTimestamp()));
+					}
+
+					// Remove any entries unchanged from last time
+					crossChainOfferSummaries.removeIf(offerSummary -> cachedInfo.previousAtModes.get(offerSummary.getQortalAtAddress()) == offerSummary.getMode());
+
+					// Skip to next blockchain if nothing has changed (for this blockchain)
+					if (crossChainOfferSummaries.isEmpty())
+						continue;
+
+					// Update
+					for (CrossChainOfferSummary offerSummary : crossChainOfferSummaries) {
+						String offerAtAddress = offerSummary.getQortalAtAddress();
+
+						cachedInfo.previousAtModes.put(offerAtAddress, offerSummary.getMode());
+						LOGGER.trace(() -> String.format("Block height: %d, AT: %s, mode: %s", blockData.getHeight(), offerAtAddress, offerSummary.getMode().name()));
+
+						switch (offerSummary.getMode()) {
+							case OFFERING:
+								cachedInfo.currentSummaries.put(offerAtAddress, offerSummary);
+								cachedInfo.historicSummaries.remove(offerAtAddress);
+								break;
+
+							case REDEEMED:
+							case REFUNDED:
+							case CANCELLED:
+								cachedInfo.currentSummaries.remove(offerAtAddress);
+								cachedInfo.historicSummaries.put(offerAtAddress, offerSummary);
+								break;
+
+							case TRADING:
+								cachedInfo.currentSummaries.remove(offerAtAddress);
+								cachedInfo.historicSummaries.remove(offerAtAddress);
+								break;
+						}
+					}
+
+					// Remove any historic offers that are over 24 hours old
+					final long tooOldTimestamp = NTP.getTime() - 24 * 60 * 60 * 1000L;
+					cachedInfo.historicSummaries.values().removeIf(historicSummary -> historicSummary.getTimestamp() < tooOldTimestamp);
+				}
+
+				// Notify sessions
+				for (Session session : getSessions()) {
+					// Only send if this session has this/no preferred blockchain
+					String preferredBlockchain = sessionBlockchain.get(session);
+
+					if (preferredBlockchain == null || preferredBlockchain.equals(blockchain.name()))
+						sendOfferSummaries(session, crossChainOfferSummaries);
+				}
+
+			}
 		} catch (DataException e) {
 			// No output this time
-			return;
 		}
-
-		synchronized (previousAtModes) {
-			// Remove any entries unchanged from last time
-			crossChainOfferSummaries.removeIf(offerSummary -> previousAtModes.get(offerSummary.getQortalAtAddress()) == offerSummary.getMode());
-
-			// Don't send anything if no results
-			if (crossChainOfferSummaries.isEmpty())
-				return;
-
-			// Update
-			for (CrossChainOfferSummary offerSummary : crossChainOfferSummaries) {
-				previousAtModes.put(offerSummary.qortalAtAddress, offerSummary.getMode());
-				LOGGER.trace(() -> String.format("Block height: %d, AT: %s, mode: %s", blockData.getHeight(), offerSummary.qortalAtAddress, offerSummary.getMode().name()));
-
-				switch (offerSummary.getMode()) {
-					case OFFERING:
-						currentSummaries.put(offerSummary.qortalAtAddress, offerSummary);
-						historicSummaries.remove(offerSummary.qortalAtAddress);
-						break;
-
-					case REDEEMED:
-					case REFUNDED:
-					case CANCELLED:
-						currentSummaries.remove(offerSummary.qortalAtAddress);
-						historicSummaries.put(offerSummary.qortalAtAddress, offerSummary);
-						break;
-
-					case TRADING:
-						currentSummaries.remove(offerSummary.qortalAtAddress);
-						historicSummaries.remove(offerSummary.qortalAtAddress);
-						break;
-				}
-			}
-
-			// Remove any historic offers that are over 24 hours old
-			final long tooOldTimestamp = NTP.getTime() - 24 * 60 * 60 * 1000L;
-			historicSummaries.values().removeIf(historicSummary -> historicSummary.getTimestamp() < tooOldTimestamp);
-		}
-
-		// Notify sessions
-		for (Session session : getSessions())
-			sendOfferSummaries(session, crossChainOfferSummaries);
 	}
 
 	@OnWebSocketConnect
@@ -146,13 +173,36 @@ public class TradeOffersWebSocket extends ApiWebSocket implements Listener {
 		Map<String, List<String>> queryParams = session.getUpgradeRequest().getParameterMap();
 		final boolean includeHistoric = queryParams.get("includeHistoric") != null;
 
+		List<String> foreignBlockchains = queryParams.get("foreignBlockchain");
+		final String foreignBlockchain = foreignBlockchains == null ? null : foreignBlockchains.get(0);
+
+		// Make sure blockchain (if any) is valid
+		if (foreignBlockchain != null && SupportedBlockchain.fromString(foreignBlockchain) == null) {
+			session.close(4003, "unknown blockchain: " + foreignBlockchain);
+			return;
+		}
+
+		// Save session's preferred blockchain, if given
+		if (foreignBlockchain != null)
+			sessionBlockchain.put(session, foreignBlockchain);
+
 		List<CrossChainOfferSummary> crossChainOfferSummaries = new ArrayList<>();
 
-		synchronized (previousAtModes) {
-			crossChainOfferSummaries.addAll(currentSummaries.values());
+		synchronized (cachedInfoByBlockchain) {
+			Collection<CachedOfferInfo> cachedInfos;
 
-			if (includeHistoric)
-				crossChainOfferSummaries.addAll(historicSummaries.values());
+			if (foreignBlockchain == null)
+				// No preferred blockchain, so iterate through all of them
+				cachedInfos = cachedInfoByBlockchain.values();
+			else
+				cachedInfos = Collections.singleton(cachedInfoByBlockchain.computeIfAbsent(foreignBlockchain, k -> new CachedOfferInfo()));
+
+			for (CachedOfferInfo cachedInfo : cachedInfos) {
+				crossChainOfferSummaries.addAll(cachedInfo.currentSummaries.values());
+
+				if (includeHistoric)
+					crossChainOfferSummaries.addAll(cachedInfo.historicSummaries.values());
+			}
 		}
 
 		if (!sendOfferSummaries(session, crossChainOfferSummaries)) {
@@ -166,6 +216,9 @@ public class TradeOffersWebSocket extends ApiWebSocket implements Listener {
 	@OnWebSocketClose
 	@Override
 	public void onWebSocketClose(Session session, int statusCode, String reason) {
+		// clean up
+		sessionBlockchain.remove(session);
+
 		super.onWebSocketClose(session, statusCode, reason);
 	}
 
@@ -197,22 +250,34 @@ public class TradeOffersWebSocket extends ApiWebSocket implements Listener {
 	private static void populateCurrentSummaries(Repository repository) throws DataException {
 		// We want ALL OFFERING trades
 		Boolean isFinished = Boolean.FALSE;
-		Integer dataByteOffset = BTCACCT.MODE_BYTE_OFFSET;
-		Long expectedValue = (long) BTCACCT.Mode.OFFERING.value;
+		Long expectedValue = (long) AcctMode.OFFERING.value;
 		Integer minimumFinalHeight = null;
 
-		List<ATStateData> initialAtStates = repository.getATRepository().getMatchingFinalATStates(BTCACCT.CODE_BYTES_HASH,
-				isFinished, dataByteOffset, expectedValue, minimumFinalHeight,
-				null, null, null);
+		for (SupportedBlockchain blockchain : SupportedBlockchain.values()) {
+			Map<ByteArray, Supplier<ACCT>> acctsByCodeHash = SupportedBlockchain.getFilteredAcctMap(blockchain);
 
-		if (initialAtStates == null)
-			throw new DataException("Couldn't fetch current trades from repository");
+			CachedOfferInfo cachedInfo = cachedInfoByBlockchain.computeIfAbsent(blockchain.name(), k -> new CachedOfferInfo());
 
-		// Save initial AT modes
-		previousAtModes.putAll(initialAtStates.stream().collect(Collectors.toMap(ATStateData::getATAddress, atState -> BTCACCT.Mode.OFFERING)));
+			for (Map.Entry<ByteArray, Supplier<ACCT>> acctInfo : acctsByCodeHash.entrySet()) {
+				byte[] codeHash = acctInfo.getKey().value;
+				ACCT acct = acctInfo.getValue().get();
 
-		// Convert to offer summaries
-		currentSummaries.putAll(produceSummaries(repository, initialAtStates, null).stream().collect(Collectors.toMap(CrossChainOfferSummary::getQortalAtAddress, offerSummary -> offerSummary)));
+				Integer dataByteOffset = acct.getModeByteOffset();
+				List<ATStateData> initialAtStates = repository.getATRepository().getMatchingFinalATStates(codeHash,
+					isFinished, dataByteOffset, expectedValue, minimumFinalHeight,
+					null, null, null);
+
+				if (initialAtStates == null)
+					throw new DataException("Couldn't fetch current trades from repository");
+
+				// Save initial AT modes
+				cachedInfo.previousAtModes.putAll(initialAtStates.stream().collect(Collectors.toMap(ATStateData::getATAddress, atState -> AcctMode.OFFERING)));
+
+				// Convert to offer summaries
+				cachedInfo.currentSummaries.putAll(produceSummaries(repository, acct, initialAtStates, null).stream()
+										.collect(Collectors.toMap(CrossChainOfferSummary::getQortalAtAddress, offerSummary -> offerSummary)));
+			}
+		}
 	}
 
 	private static void populateHistoricSummaries(Repository repository) throws DataException {
@@ -228,33 +293,44 @@ public class TradeOffersWebSocket extends ApiWebSocket implements Listener {
 		Long expectedValue = null;
 		++minimumFinalHeight; // because height is just *before* timestamp
 
-		List<ATStateData> historicAtStates = repository.getATRepository().getMatchingFinalATStates(BTCACCT.CODE_BYTES_HASH,
-				isFinished, dataByteOffset, expectedValue, minimumFinalHeight,
-				null, null, null);
+		for (SupportedBlockchain blockchain : SupportedBlockchain.values()) {
+			Map<ByteArray, Supplier<ACCT>> acctsByCodeHash = SupportedBlockchain.getFilteredAcctMap(blockchain);
 
-		if (historicAtStates == null)
-			throw new DataException("Couldn't fetch historic trades from repository");
+			CachedOfferInfo cachedInfo = cachedInfoByBlockchain.computeIfAbsent(blockchain.name(), k -> new CachedOfferInfo());
 
-		for (ATStateData historicAtState : historicAtStates) {
-			CrossChainOfferSummary historicOfferSummary = produceSummary(repository, historicAtState, null);
+			for (Map.Entry<ByteArray, Supplier<ACCT>> acctInfo : acctsByCodeHash.entrySet()) {
+				byte[] codeHash = acctInfo.getKey().value;
+				ACCT acct = acctInfo.getValue().get();
 
-			if (!isHistoric.test(historicOfferSummary))
-				continue;
+				List<ATStateData> historicAtStates = repository.getATRepository().getMatchingFinalATStates(codeHash,
+					isFinished, dataByteOffset, expectedValue, minimumFinalHeight,
+					null, null, null);
 
-			// Add summary to initial burst
-			historicSummaries.put(historicOfferSummary.getQortalAtAddress(), historicOfferSummary);
+				if (historicAtStates == null)
+					throw new DataException("Couldn't fetch historic trades from repository");
 
-			// Save initial AT mode
-			previousAtModes.put(historicOfferSummary.getQortalAtAddress(), historicOfferSummary.getMode());
+				for (ATStateData historicAtState : historicAtStates) {
+					CrossChainOfferSummary historicOfferSummary = produceSummary(repository, acct, historicAtState, null);
+
+					if (!isHistoric.test(historicOfferSummary))
+						continue;
+
+					// Add summary to initial burst
+					cachedInfo.historicSummaries.put(historicOfferSummary.getQortalAtAddress(), historicOfferSummary);
+
+					// Save initial AT mode
+					cachedInfo.previousAtModes.put(historicOfferSummary.getQortalAtAddress(), historicOfferSummary.getMode());
+				}
+			}
 		}
 	}
 
-	private static CrossChainOfferSummary produceSummary(Repository repository, ATStateData atState, Long timestamp) throws DataException {
-		CrossChainTradeData crossChainTradeData = BTCACCT.populateTradeData(repository, atState);
+	private static CrossChainOfferSummary produceSummary(Repository repository, ACCT acct, ATStateData atState, Long timestamp) throws DataException {
+		CrossChainTradeData crossChainTradeData = acct.populateTradeData(repository, atState);
 
 		long atStateTimestamp;
 
-		if (crossChainTradeData.mode == BTCACCT.Mode.OFFERING)
+		if (crossChainTradeData.mode == AcctMode.OFFERING)
 			// We want when trade was created, not when it was last updated
 			atStateTimestamp = crossChainTradeData.creationTimestamp;
 		else
@@ -263,11 +339,11 @@ public class TradeOffersWebSocket extends ApiWebSocket implements Listener {
 		return new CrossChainOfferSummary(crossChainTradeData, atStateTimestamp);
 	}
 
-	private static List<CrossChainOfferSummary> produceSummaries(Repository repository, List<ATStateData> atStates, Long timestamp) throws DataException {
+	private static List<CrossChainOfferSummary> produceSummaries(Repository repository, ACCT acct, List<ATStateData> atStates, Long timestamp) throws DataException {
 		List<CrossChainOfferSummary> offerSummaries = new ArrayList<>();
 
 		for (ATStateData atState : atStates)
-			offerSummaries.add(produceSummary(repository, atState, timestamp));
+			offerSummaries.add(produceSummary(repository, acct, atState, timestamp));
 
 		return offerSummaries;
 	}

src/main/java/org/qortal/at/QortalFunctionCode.java

@@ -10,7 +10,7 @@ import org.ciyam.at.ExecutionException;
 import org.ciyam.at.FunctionData;
 import org.ciyam.at.IllegalFunctionCodeException;
 import org.ciyam.at.MachineState;
-import org.qortal.crosschain.BTC;
+import org.qortal.crosschain.Bitcoin;
 import org.qortal.crypto.Crypto;
 import org.qortal.data.transaction.TransactionData;
 import org.qortal.settings.Settings;
@@ -108,7 +108,7 @@ public enum QortalFunctionCode {
 	CONVERT_B_TO_P2SH(0x0511, 0, false) {
 		@Override
 		protected void postCheckExecute(FunctionData functionData, MachineState state, short rawFunctionCode) throws ExecutionException {
-			byte addressPrefix = Settings.getInstance().getBitcoinNet() == BTC.BitcoinNet.MAIN ? 0x05 : (byte) 0xc4;
+			byte addressPrefix = Settings.getInstance().getBitcoinNet() == Bitcoin.BitcoinNet.MAIN ? 0x05 : (byte) 0xc4;
 
 			convertAddressInB(addressPrefix, state);
 		}

src/main/java/org/qortal/controller/BlockMinter.java

@@ -294,8 +294,12 @@ public class BlockMinter extends Thread {
 									newBlock.getMinter().getAddress()));
 						}
 
-						// Notify controller after we're released blockchain lock
+						// Notify network after we're released blockchain lock
 						newBlockMinted = true;
+
+						// Notify Controller
+						repository.discardChanges(); // clear transaction status to prevent deadlocks
+						Controller.getInstance().onNewBlock(newBlock.getBlockData());
 					} catch (DataException e) {
 						// Unable to process block - report and discard
 						LOGGER.error("Unable to process newly minted block?", e);
@@ -306,12 +310,9 @@ public class BlockMinter extends Thread {
 				}
 
 				if (newBlockMinted) {
-					// Notify Controller and broadcast our new chain to network
+					// Broadcast our new chain to network
 					BlockData newBlockData = newBlock.getBlockData();
 
-					repository.discardChanges(); // clear transaction status to prevent deadlocks
-					Controller.getInstance().onNewBlock(newBlockData);
-
 					Network network = Network.getInstance();
 					network.broadcast(broadcastPeer -> network.buildHeightMessage(broadcastPeer, newBlockData));
 				}

src/main/java/org/qortal/controller/Controller.java

@@ -46,6 +46,7 @@ import org.qortal.block.Block;
 import org.qortal.block.BlockChain;
 import org.qortal.block.BlockChain.BlockTimingByHeight;
 import org.qortal.controller.Synchronizer.SynchronizationResult;
+import org.qortal.controller.tradebot.TradeBot;
 import org.qortal.crypto.Crypto;
 import org.qortal.data.account.MintingAccountData;
 import org.qortal.data.account.RewardShareData;
@@ -799,11 +800,14 @@ public class Controller extends Thread {
 
 			List<TransactionData> transactions = repository.getTransactionRepository().getUnconfirmedTransactions();
 
-			for (TransactionData transactionData : transactions)
-				if (now >= Transaction.getDeadline(transactionData)) {
-					LOGGER.info(String.format("Deleting expired, unconfirmed transaction %s", Base58.encode(transactionData.getSignature())));
+			for (TransactionData transactionData : transactions) {
+				Transaction transaction = Transaction.fromData(repository, transactionData);
+
+				if (now >= transaction.getDeadline()) {
+					LOGGER.info(() -> String.format("Deleting expired, unconfirmed transaction %s", Base58.encode(transactionData.getSignature())));
 					repository.getTransactionRepository().delete(transactionData);
 				}
+			}
 
 			repository.saveChanges();
 		} catch (DataException e) {
@@ -1032,11 +1036,31 @@ public class Controller extends Thread {
 		}
 	}
 
-	/** Callback for when we've received a new transaction via API or peer. */
-	public void onNewTransaction(TransactionData transactionData, Peer peer) {
+	public static class NewTransactionEvent implements Event {
+		private final TransactionData transactionData;
+
+		public NewTransactionEvent(TransactionData transactionData) {
+			this.transactionData = transactionData;
+		}
+
+		public TransactionData getTransactionData() {
+			return this.transactionData;
+		}
+	}
+
+	/**
+	 * Callback for when we've received a new transaction via API or peer.
+	 * <p>
+	 * @implSpec performs actions in a new thread
+	 */
+	public void onNewTransaction(TransactionData transactionData) {
 		this.callbackExecutor.execute(() -> {
-			// Notify all peers (except maybe peer that sent it to us if applicable)
-			Network.getInstance().broadcast(broadcastPeer -> broadcastPeer == peer ? null : new TransactionSignaturesMessage(Arrays.asList(transactionData.getSignature())));
+			// Notify all peers
+			Message newTransactionSignatureMessage = new TransactionSignaturesMessage(Arrays.asList(transactionData.getSignature()));
+			Network.getInstance().broadcast(broadcastPeer -> newTransactionSignatureMessage);
+
+			// Notify listeners
+			EventBus.INSTANCE.notify(new NewTransactionEvent(transactionData));
 
 			// If this is a CHAT transaction, there may be extra listeners to notify
 			if (transactionData.getType() == TransactionType.CHAT)
@@ -1215,9 +1239,6 @@ public class Controller extends Thread {
 		} catch (DataException e) {
 			LOGGER.error(String.format("Repository issue while processing transaction %s from peer %s", Base58.encode(transactionData.getSignature()), peer), e);
 		}
-
-		// Notify controller so it can notify other peers, etc.
-		Controller.getInstance().onNewTransaction(transactionData, peer);
 	}
 
 	private void onNetworkGetBlockSummariesMessage(Peer peer, Message message) {

src/main/java/org/qortal/controller/tradebot/AcctTradeBot.java

@@ -0,0 +1,30 @@
+package org.qortal.controller.tradebot;
+
+import java.util.List;
+
+import org.qortal.api.model.crosschain.TradeBotCreateRequest;
+import org.qortal.crosschain.ACCT;
+import org.qortal.crosschain.ForeignBlockchainException;
+import org.qortal.data.at.ATData;
+import org.qortal.data.crosschain.CrossChainTradeData;
+import org.qortal.data.crosschain.TradeBotData;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+
+public interface AcctTradeBot {
+
+	public enum ResponseResult { OK, BALANCE_ISSUE, NETWORK_ISSUE, TRADE_ALREADY_EXISTS }
+
+	/** Returns list of state names for trade-bot entries that have ended, e.g. redeemed, refunded or cancelled. */
+	public List<String> getEndStates();
+
+	public byte[] createTrade(Repository repository, TradeBotCreateRequest tradeBotCreateRequest) throws DataException;
+
+	public ResponseResult startResponse(Repository repository, ATData atData, ACCT acct,
+			CrossChainTradeData crossChainTradeData, String foreignKey, String receivingAddress) throws DataException;
+
+	public boolean canDelete(Repository repository, TradeBotData tradeBotData);
+
+	public void progress(Repository repository, TradeBotData tradeBotData) throws DataException, ForeignBlockchainException;
+
+}

src/main/java/org/qortal/controller/tradebot/LitecoinACCTv1TradeBot.java

@@ -0,0 +1,884 @@
+package org.qortal.controller.tradebot;
+
+import static java.util.Arrays.stream;
+import static java.util.stream.Collectors.toMap;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.bitcoinj.core.Address;
+import org.bitcoinj.core.AddressFormatException;
+import org.bitcoinj.core.Coin;
+import org.bitcoinj.core.ECKey;
+import org.bitcoinj.core.Transaction;
+import org.bitcoinj.core.TransactionOutput;
+import org.bitcoinj.script.Script.ScriptType;
+import org.qortal.account.PrivateKeyAccount;
+import org.qortal.account.PublicKeyAccount;
+import org.qortal.api.model.crosschain.TradeBotCreateRequest;
+import org.qortal.asset.Asset;
+import org.qortal.crosschain.ACCT;
+import org.qortal.crosschain.AcctMode;
+import org.qortal.crosschain.ForeignBlockchainException;
+import org.qortal.crosschain.Litecoin;
+import org.qortal.crosschain.LitecoinACCTv1;
+import org.qortal.crosschain.SupportedBlockchain;
+import org.qortal.crosschain.BitcoinyHTLC;
+import org.qortal.crypto.Crypto;
+import org.qortal.data.at.ATData;
+import org.qortal.data.crosschain.CrossChainTradeData;
+import org.qortal.data.crosschain.TradeBotData;
+import org.qortal.data.transaction.BaseTransactionData;
+import org.qortal.data.transaction.DeployAtTransactionData;
+import org.qortal.data.transaction.MessageTransactionData;
+import org.qortal.group.Group;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.transaction.DeployAtTransaction;
+import org.qortal.transaction.MessageTransaction;
+import org.qortal.transaction.Transaction.ValidationResult;
+import org.qortal.transform.TransformationException;
+import org.qortal.transform.transaction.DeployAtTransactionTransformer;
+import org.qortal.utils.Base58;
+import org.qortal.utils.NTP;
+
+/**
+ * Performing cross-chain trading steps on behalf of user.
+ * <p>
+ * We deal with three different independent state-spaces here:
+ * <ul>
+ * 	<li>Qortal blockchain</li>
+ * 	<li>Foreign blockchain</li>
+ * 	<li>Trade-bot entries</li>
+ * </ul>
+ */
+public class LitecoinACCTv1TradeBot implements AcctTradeBot {
+
+	private static final Logger LOGGER = LogManager.getLogger(LitecoinACCTv1TradeBot.class);
+
+	public enum State implements TradeBot.StateNameAndValueSupplier {
+		BOB_WAITING_FOR_AT_CONFIRM(10, false, false),
+		BOB_WAITING_FOR_MESSAGE(15, true, true),
+		BOB_WAITING_FOR_AT_REDEEM(25, true, true),
+		BOB_DONE(30, false, false),
+		BOB_REFUNDED(35, false, false),
+
+		ALICE_WAITING_FOR_AT_LOCK(85, true, true),
+		ALICE_DONE(95, false, false),
+		ALICE_REFUNDING_A(105, true, true),
+		ALICE_REFUNDED(110, false, false);
+
+		private static final Map<Integer, State> map = stream(State.values()).collect(toMap(state -> state.value, state -> state));
+
+		public final int value;
+		public final boolean requiresAtData;
+		public final boolean requiresTradeData;
+
+		State(int value, boolean requiresAtData, boolean requiresTradeData) {
+			this.value = value;
+			this.requiresAtData = requiresAtData;
+			this.requiresTradeData = requiresTradeData;
+		}
+
+		public static State valueOf(int value) {
+			return map.get(value);
+		}
+
+		@Override
+		public String getState() {
+			return this.name();
+		}
+
+		@Override
+		public int getStateValue() {
+			return this.value;
+		}
+	}
+
+	/** Maximum time Bob waits for his AT creation transaction to be confirmed into a block. (milliseconds) */
+	private static final long MAX_AT_CONFIRMATION_PERIOD = 24 * 60 * 60 * 1000L; // ms
+
+	private static LitecoinACCTv1TradeBot instance;
+
+	private final List<String> endStates = Arrays.asList(State.BOB_DONE, State.BOB_REFUNDED, State.ALICE_DONE, State.ALICE_REFUNDING_A, State.ALICE_REFUNDED).stream()
+			.map(State::name)
+			.collect(Collectors.toUnmodifiableList());
+
+	private LitecoinACCTv1TradeBot() {
+	}
+
+	public static synchronized LitecoinACCTv1TradeBot getInstance() {
+		if (instance == null)
+			instance = new LitecoinACCTv1TradeBot();
+
+		return instance;
+	}
+
+	@Override
+	public List<String> getEndStates() {
+		return this.endStates;
+	}
+
+	/**
+	 * Creates a new trade-bot entry from the "Bob" viewpoint, i.e. OFFERing QORT in exchange for LTC.
+	 * <p>
+	 * Generates:
+	 * <ul>
+	 * 	<li>new 'trade' private key</li>
+	 * </ul>
+	 * Derives:
+	 * <ul>
+	 * 	<li>'native' (as in Qortal) public key, public key hash, address (starting with Q)</li>
+	 * 	<li>'foreign' (as in Litecoin) public key, public key hash</li>
+	 * </ul>
+	 * A Qortal AT is then constructed including the following as constants in the 'data segment':
+	 * <ul>
+	 * 	<li>'native'/Qortal 'trade' address - used as a MESSAGE contact</li>
+	 * 	<li>'foreign'/Litecoin public key hash - used by Alice's P2SH scripts to allow redeem</li>
+	 * 	<li>QORT amount on offer by Bob</li>
+	 * 	<li>LTC amount expected in return by Bob (from Alice)</li>
+	 * 	<li>trading timeout, in case things go wrong and everyone needs to refund</li>
+	 * </ul>
+	 * Returns a DEPLOY_AT transaction that needs to be signed and broadcast to the Qortal network.
+	 * <p>
+	 * Trade-bot will wait for Bob's AT to be deployed before taking next step.
+	 * <p>
+	 * @param repository
+	 * @param tradeBotCreateRequest
+	 * @return raw, unsigned DEPLOY_AT transaction
+	 * @throws DataException
+	 */
+	public byte[] createTrade(Repository repository, TradeBotCreateRequest tradeBotCreateRequest) throws DataException {
+		byte[] tradePrivateKey = TradeBot.generateTradePrivateKey();
+
+		byte[] tradeNativePublicKey = TradeBot.deriveTradeNativePublicKey(tradePrivateKey);
+		byte[] tradeNativePublicKeyHash = Crypto.hash160(tradeNativePublicKey);
+		String tradeNativeAddress = Crypto.toAddress(tradeNativePublicKey);
+
+		byte[] tradeForeignPublicKey = TradeBot.deriveTradeForeignPublicKey(tradePrivateKey);
+		byte[] tradeForeignPublicKeyHash = Crypto.hash160(tradeForeignPublicKey);
+
+		// Convert Litecoin receiving address into public key hash (we only support P2PKH at this time)
+		Address litecoinReceivingAddress;
+		try {
+			litecoinReceivingAddress = Address.fromString(Litecoin.getInstance().getNetworkParameters(), tradeBotCreateRequest.receivingAddress);
+		} catch (AddressFormatException e) {
+			throw new DataException("Unsupported Litecoin receiving address: " + tradeBotCreateRequest.receivingAddress);
+		}
+		if (litecoinReceivingAddress.getOutputScriptType() != ScriptType.P2PKH)
+			throw new DataException("Unsupported Litecoin receiving address: " + tradeBotCreateRequest.receivingAddress);
+
+		byte[] litecoinReceivingAccountInfo = litecoinReceivingAddress.getHash();
+
+		PublicKeyAccount creator = new PublicKeyAccount(repository, tradeBotCreateRequest.creatorPublicKey);
+
+		// Deploy AT
+		long timestamp = NTP.getTime();
+		byte[] reference = creator.getLastReference();
+		long fee = 0L;
+		byte[] signature = null;
+		BaseTransactionData baseTransactionData = new BaseTransactionData(timestamp, Group.NO_GROUP, reference, creator.getPublicKey(), fee, signature);
+
+		String name = "QORT/LTC ACCT";
+		String description = "QORT/LTC cross-chain trade";
+		String aTType = "ACCT";
+		String tags = "ACCT QORT LTC";
+		byte[] creationBytes = LitecoinACCTv1.buildQortalAT(tradeNativeAddress, tradeForeignPublicKeyHash, tradeBotCreateRequest.qortAmount,
+				tradeBotCreateRequest.foreignAmount, tradeBotCreateRequest.tradeTimeout);
+		long amount = tradeBotCreateRequest.fundingQortAmount;
+
+		DeployAtTransactionData deployAtTransactionData = new DeployAtTransactionData(baseTransactionData, name, description, aTType, tags, creationBytes, amount, Asset.QORT);
+
+		DeployAtTransaction deployAtTransaction = new DeployAtTransaction(repository, deployAtTransactionData);
+		fee = deployAtTransaction.calcRecommendedFee();
+		deployAtTransactionData.setFee(fee);
+
+		DeployAtTransaction.ensureATAddress(deployAtTransactionData);
+		String atAddress = deployAtTransactionData.getAtAddress();
+
+		TradeBotData tradeBotData =  new TradeBotData(tradePrivateKey, LitecoinACCTv1.NAME,
+				State.BOB_WAITING_FOR_AT_CONFIRM.name(), State.BOB_WAITING_FOR_AT_CONFIRM.value,
+				creator.getAddress(), atAddress, timestamp, tradeBotCreateRequest.qortAmount,
+				tradeNativePublicKey, tradeNativePublicKeyHash, tradeNativeAddress,
+				null, null,
+				SupportedBlockchain.LITECOIN.name(),
+				tradeForeignPublicKey, tradeForeignPublicKeyHash,
+				tradeBotCreateRequest.foreignAmount, null, null, null, litecoinReceivingAccountInfo);
+
+		TradeBot.updateTradeBotState(repository, tradeBotData, () -> String.format("Built AT %s. Waiting for deployment", atAddress));
+
+		// Return to user for signing and broadcast as we don't have their Qortal private key
+		try {
+			return DeployAtTransactionTransformer.toBytes(deployAtTransactionData);
+		} catch (TransformationException e) {
+			throw new DataException("Failed to transform DEPLOY_AT transaction?", e);
+		}
+	}
+
+	/**
+	 * Creates a trade-bot entry from the 'Alice' viewpoint, i.e. matching LTC to an existing offer.
+	 * <p>
+	 * Requires a chosen trade offer from Bob, passed by <tt>crossChainTradeData</tt>
+	 * and access to a Litecoin wallet via <tt>xprv58</tt>.
+	 * <p>
+	 * The <tt>crossChainTradeData</tt> contains the current trade offer state
+	 * as extracted from the AT's data segment.
+	 * <p>
+	 * Access to a funded wallet is via a Litecoin BIP32 hierarchical deterministic key,
+	 * passed via <tt>xprv58</tt>.
+	 * <b>This key will be stored in your node's database</b>
+	 * to allow trade-bot to create/fund the necessary P2SH transactions!
+	 * However, due to the nature of BIP32 keys, it is possible to give the trade-bot
+	 * only a subset of wallet access (see BIP32 for more details).
+	 * <p>
+	 * As an example, the xprv58 can be extract from a <i>legacy, password-less</i>
+	 * Electrum wallet by going to the console tab and entering:<br>
+	 * <tt>wallet.keystore.xprv</tt><br>
+	 * which should result in a base58 string starting with either 'xprv' (for Litecoin main-net)
+	 * or 'tprv' for (Litecoin test-net).
+	 * <p>
+	 * It is envisaged that the value in <tt>xprv58</tt> will actually come from a Qortal-UI-managed wallet.
+	 * <p>
+	 * If sufficient funds are available, <b>this method will actually fund the P2SH-A</b>
+	 * with the Litecoin amount expected by 'Bob'.
+	 * <p>
+	 * If the Litecoin transaction is successfully broadcast to the network then
+	 * we also send a MESSAGE to Bob's trade-bot to let them know.
+	 * <p>
+	 * The trade-bot entry is saved to the repository and the cross-chain trading process commences.
+	 * <p>
+	 * @param repository
+	 * @param crossChainTradeData chosen trade OFFER that Alice wants to match
+	 * @param xprv58 funded wallet xprv in base58
+	 * @return true if P2SH-A funding transaction successfully broadcast to Litecoin network, false otherwise
+	 * @throws DataException
+	 */
+	public ResponseResult startResponse(Repository repository, ATData atData, ACCT acct, CrossChainTradeData crossChainTradeData, String xprv58, String receivingAddress) throws DataException {
+		byte[] tradePrivateKey = TradeBot.generateTradePrivateKey();
+		byte[] secretA = TradeBot.generateSecret();
+		byte[] hashOfSecretA = Crypto.hash160(secretA);
+
+		byte[] tradeNativePublicKey = TradeBot.deriveTradeNativePublicKey(tradePrivateKey);
+		byte[] tradeNativePublicKeyHash = Crypto.hash160(tradeNativePublicKey);
+		String tradeNativeAddress = Crypto.toAddress(tradeNativePublicKey);
+
+		byte[] tradeForeignPublicKey = TradeBot.deriveTradeForeignPublicKey(tradePrivateKey);
+		byte[] tradeForeignPublicKeyHash = Crypto.hash160(tradeForeignPublicKey);
+		byte[] receivingPublicKeyHash = Base58.decode(receivingAddress); // Actually the whole address, not just PKH
+
+		// We need to generate lockTime-A: add tradeTimeout to now
+		long now = NTP.getTime();
+		int lockTimeA = crossChainTradeData.tradeTimeout * 60 + (int) (now / 1000L);
+
+		TradeBotData tradeBotData =  new TradeBotData(tradePrivateKey, LitecoinACCTv1.NAME,
+				State.ALICE_WAITING_FOR_AT_LOCK.name(), State.ALICE_WAITING_FOR_AT_LOCK.value,
+				receivingAddress, crossChainTradeData.qortalAtAddress, now, crossChainTradeData.qortAmount,
+				tradeNativePublicKey, tradeNativePublicKeyHash, tradeNativeAddress,
+				secretA, hashOfSecretA,
+				SupportedBlockchain.LITECOIN.name(),
+				tradeForeignPublicKey, tradeForeignPublicKeyHash,
+				crossChainTradeData.expectedForeignAmount, xprv58, null, lockTimeA, receivingPublicKeyHash);
+
+		// Check we have enough funds via xprv58 to fund P2SH to cover expectedForeignAmount
+		long p2shFee;
+		try {
+			p2shFee = Litecoin.getInstance().getP2shFee(now);
+		} catch (ForeignBlockchainException e) {
+			LOGGER.debug("Couldn't estimate Litecoin fees?");
+			return ResponseResult.NETWORK_ISSUE;
+		}
+
+		// Fee for redeem/refund is subtracted from P2SH-A balance.
+		// Do not include fee for funding transaction as this is covered by buildSpend()
+		long amountA = crossChainTradeData.expectedForeignAmount + p2shFee /*redeeming/refunding P2SH-A*/;
+
+		// P2SH-A to be funded
+		byte[] redeemScriptBytes = BitcoinyHTLC.buildScript(tradeForeignPublicKeyHash, lockTimeA, crossChainTradeData.creatorForeignPKH, hashOfSecretA);
+		String p2shAddress = Litecoin.getInstance().deriveP2shAddress(redeemScriptBytes);
+
+		// Build transaction for funding P2SH-A
+		Transaction p2shFundingTransaction = Litecoin.getInstance().buildSpend(tradeBotData.getForeignKey(), p2shAddress, amountA);
+		if (p2shFundingTransaction == null) {
+			LOGGER.debug("Unable to build P2SH-A funding transaction - lack of funds?");
+			return ResponseResult.BALANCE_ISSUE;
+		}
+
+		try {
+			Litecoin.getInstance().broadcastTransaction(p2shFundingTransaction);
+		} catch (ForeignBlockchainException e) {
+			// We couldn't fund P2SH-A at this time
+			LOGGER.debug("Couldn't broadcast P2SH-A funding transaction?");
+			return ResponseResult.NETWORK_ISSUE;
+		}
+
+		// Attempt to send MESSAGE to Bob's Qortal trade address
+		byte[] messageData = LitecoinACCTv1.buildOfferMessage(tradeBotData.getTradeForeignPublicKeyHash(), tradeBotData.getHashOfSecret(), tradeBotData.getLockTimeA());
+		String messageRecipient = crossChainTradeData.qortalCreatorTradeAddress;
+
+		boolean isMessageAlreadySent = repository.getMessageRepository().exists(tradeBotData.getTradeNativePublicKey(), messageRecipient, messageData);
+		if (!isMessageAlreadySent) {
+			PrivateKeyAccount sender = new PrivateKeyAccount(repository, tradeBotData.getTradePrivateKey());
+			MessageTransaction messageTransaction = MessageTransaction.build(repository, sender, Group.NO_GROUP, messageRecipient, messageData, false, false);
+
+			messageTransaction.computeNonce();
+			messageTransaction.sign(sender);
+
+			// reset repository state to prevent deadlock
+			repository.discardChanges();
+			ValidationResult result = messageTransaction.importAsUnconfirmed();
+
+			if (result != ValidationResult.OK) {
+				LOGGER.warn(() -> String.format("Unable to send MESSAGE to Bob's trade-bot %s: %s", messageRecipient, result.name()));
+				return ResponseResult.NETWORK_ISSUE;
+			}
+		}
+
+		TradeBot.updateTradeBotState(repository, tradeBotData, () -> String.format("Funding P2SH-A %s. Messaged Bob. Waiting for AT-lock", p2shAddress));
+
+		return ResponseResult.OK;
+	}
+
+	@Override
+	public boolean canDelete(Repository repository, TradeBotData tradeBotData) {
+		State tradeBotState = State.valueOf(tradeBotData.getStateValue());
+		if (tradeBotState == null)
+			return true;
+
+		switch (tradeBotState) {
+			case BOB_WAITING_FOR_AT_CONFIRM:
+			case ALICE_DONE:
+			case BOB_DONE:
+			case ALICE_REFUNDED:
+			case BOB_REFUNDED:
+				return true;
+
+			default:
+				return false;
+		}
+	}
+
+	@Override
+	public void progress(Repository repository, TradeBotData tradeBotData) throws DataException, ForeignBlockchainException {
+		State tradeBotState = State.valueOf(tradeBotData.getStateValue());
+		if (tradeBotState == null) {
+			LOGGER.info(() -> String.format("Trade-bot entry for AT %s has invalid state?", tradeBotData.getAtAddress()));
+			return;
+		}
+
+		ATData atData = null;
+		CrossChainTradeData tradeData = null;
+
+		if (tradeBotState.requiresAtData) {
+			// Attempt to fetch AT data
+			atData = repository.getATRepository().fromATAddress(tradeBotData.getAtAddress());
+			if (atData == null) {
+				LOGGER.warn(() -> String.format("Unable to fetch trade AT %s from repository", tradeBotData.getAtAddress()));
+				return;
+			}
+
+			if (tradeBotState.requiresTradeData) {
+				tradeData = LitecoinACCTv1.getInstance().populateTradeData(repository, atData);
+				if (tradeData == null) {
+					LOGGER.warn(() -> String.format("Unable to fetch ACCT trade data for AT %s from repository", tradeBotData.getAtAddress()));
+					return;
+				}
+			}
+		}
+
+		switch (tradeBotState) {
+			case BOB_WAITING_FOR_AT_CONFIRM:
+				handleBobWaitingForAtConfirm(repository, tradeBotData);
+				break;
+
+			case BOB_WAITING_FOR_MESSAGE:
+				TradeBot.getInstance().updatePresence(repository, tradeBotData, tradeData);
+				handleBobWaitingForMessage(repository, tradeBotData, atData, tradeData);
+				break;
+
+			case ALICE_WAITING_FOR_AT_LOCK:
+				TradeBot.getInstance().updatePresence(repository, tradeBotData, tradeData);
+				handleAliceWaitingForAtLock(repository, tradeBotData, atData, tradeData);
+				break;
+
+			case BOB_WAITING_FOR_AT_REDEEM:
+				TradeBot.getInstance().updatePresence(repository, tradeBotData, tradeData);
+				handleBobWaitingForAtRedeem(repository, tradeBotData, atData, tradeData);
+				break;
+
+			case ALICE_DONE:
+			case BOB_DONE:
+				break;
+
+			case ALICE_REFUNDING_A:
+				TradeBot.getInstance().updatePresence(repository, tradeBotData, tradeData);
+				handleAliceRefundingP2shA(repository, tradeBotData, atData, tradeData);
+				break;
+
+			case ALICE_REFUNDED:
+			case BOB_REFUNDED:
+				break;
+		}
+	}
+
+	/**
+	 * Trade-bot is waiting for Bob's AT to deploy.
+	 * <p>
+	 * If AT is deployed, then trade-bot's next step is to wait for MESSAGE from Alice.
+	 */
+	private void handleBobWaitingForAtConfirm(Repository repository, TradeBotData tradeBotData) throws DataException {
+		if (!repository.getATRepository().exists(tradeBotData.getAtAddress())) {
+			if (NTP.getTime() - tradeBotData.getTimestamp() <= MAX_AT_CONFIRMATION_PERIOD)
+				return;
+
+			// We've waited ages for AT to be confirmed into a block but something has gone awry.
+			// After this long we assume transaction loss so give up with trade-bot entry too.
+			tradeBotData.setState(State.BOB_REFUNDED.name());
+			tradeBotData.setStateValue(State.BOB_REFUNDED.value);
+			tradeBotData.setTimestamp(NTP.getTime());
+			// We delete trade-bot entry here instead of saving, hence not using updateTradeBotState()
+			repository.getCrossChainRepository().delete(tradeBotData.getTradePrivateKey());
+			repository.saveChanges();
+
+			LOGGER.info(() -> String.format("AT %s never confirmed. Giving up on trade", tradeBotData.getAtAddress()));
+			TradeBot.notifyStateChange(tradeBotData);
+			return;
+		}
+
+		TradeBot.updateTradeBotState(repository, tradeBotData, State.BOB_WAITING_FOR_MESSAGE,
+				() -> String.format("AT %s confirmed ready. Waiting for trade message", tradeBotData.getAtAddress()));
+	}
+
+	/**
+	 * Trade-bot is waiting for MESSAGE from Alice's trade-bot, containing Alice's trade info.
+	 * <p>
+	 * It's possible Bob has cancelling his trade offer, receiving an automatic QORT refund,
+	 * in which case trade-bot is done with this specific trade and finalizes on refunded state.
+	 * <p>
+	 * Assuming trade is still on offer, trade-bot checks the contents of MESSAGE from Alice's trade-bot.
+	 * <p>
+	 * Details from Alice are used to derive P2SH-A address and this is checked for funding balance.
+	 * <p>
+	 * Assuming P2SH-A has at least expected Litecoin balance,
+	 * Bob's trade-bot constructs a zero-fee, PoW MESSAGE to send to Bob's AT with more trade details.
+	 * <p>
+	 * On processing this MESSAGE, Bob's AT should switch into 'TRADE' mode and only trade with Alice.
+	 * <p>
+	 * Trade-bot's next step is to wait for Alice to redeem the AT, which will allow Bob to
+	 * extract secret-A needed to redeem Alice's P2SH.
+	 * @throws ForeignBlockchainException
+	 */
+	private void handleBobWaitingForMessage(Repository repository, TradeBotData tradeBotData,
+			ATData atData, CrossChainTradeData crossChainTradeData) throws DataException, ForeignBlockchainException {
+		// If AT has finished then Bob likely cancelled his trade offer
+		if (atData.getIsFinished()) {
+			TradeBot.updateTradeBotState(repository, tradeBotData, State.BOB_REFUNDED,
+					() -> String.format("AT %s cancelled - trading aborted", tradeBotData.getAtAddress()));
+			return;
+		}
+
+		Litecoin litecoin = Litecoin.getInstance();
+
+		String address = tradeBotData.getTradeNativeAddress();
+		List<MessageTransactionData> messageTransactionsData = repository.getMessageRepository().getMessagesByParticipants(null, address, null, null, null);
+
+		for (MessageTransactionData messageTransactionData : messageTransactionsData) {
+			if (messageTransactionData.isText())
+				continue;
+
+			// We're expecting: HASH160(secret-A), Alice's Litecoin pubkeyhash and lockTime-A
+			byte[] messageData = messageTransactionData.getData();
+			LitecoinACCTv1.OfferMessageData offerMessageData = LitecoinACCTv1.extractOfferMessageData(messageData);
+			if (offerMessageData == null)
+				continue;
+
+			byte[] aliceForeignPublicKeyHash = offerMessageData.partnerLitecoinPKH;
+			byte[] hashOfSecretA = offerMessageData.hashOfSecretA;
+			int lockTimeA = (int) offerMessageData.lockTimeA;
+			long messageTimestamp = messageTransactionData.getTimestamp();
+			int refundTimeout = LitecoinACCTv1.calcRefundTimeout(messageTimestamp, lockTimeA);
+
+			// Determine P2SH-A address and confirm funded
+			byte[] redeemScriptA = BitcoinyHTLC.buildScript(aliceForeignPublicKeyHash, lockTimeA, tradeBotData.getTradeForeignPublicKeyHash(), hashOfSecretA);
+			String p2shAddressA = litecoin.deriveP2shAddress(redeemScriptA);
+
+			long feeTimestamp = calcFeeTimestamp(lockTimeA, crossChainTradeData.tradeTimeout);
+			long p2shFee = Litecoin.getInstance().getP2shFee(feeTimestamp);
+			final long minimumAmountA = tradeBotData.getForeignAmount() + p2shFee;
+
+			BitcoinyHTLC.Status htlcStatusA = BitcoinyHTLC.determineHtlcStatus(litecoin.getBlockchainProvider(), p2shAddressA, minimumAmountA);
+
+			switch (htlcStatusA) {
+				case UNFUNDED:
+				case FUNDING_IN_PROGRESS:
+					// There might be another MESSAGE from someone else with an actually funded P2SH-A...
+					continue;
+
+				case REDEEM_IN_PROGRESS:
+				case REDEEMED:
+					// We've already redeemed this?
+					TradeBot.updateTradeBotState(repository, tradeBotData, State.BOB_DONE,
+							() -> String.format("P2SH-A %s already spent? Assuming trade complete", p2shAddressA));
+					return;
+
+				case REFUND_IN_PROGRESS:
+				case REFUNDED:
+					// This P2SH-A is burnt, but there might be another MESSAGE from someone else with an actually funded P2SH-A...
+					continue;
+
+				case FUNDED:
+					// Fall-through out of switch...
+					break;
+			}
+
+			// Good to go - send MESSAGE to AT
+
+			String aliceNativeAddress = Crypto.toAddress(messageTransactionData.getCreatorPublicKey());
+
+			// Build outgoing message, padding each part to 32 bytes to make it easier for AT to consume
+			byte[] outgoingMessageData = LitecoinACCTv1.buildTradeMessage(aliceNativeAddress, aliceForeignPublicKeyHash, hashOfSecretA, lockTimeA, refundTimeout);
+			String messageRecipient = tradeBotData.getAtAddress();
+
+			boolean isMessageAlreadySent = repository.getMessageRepository().exists(tradeBotData.getTradeNativePublicKey(), messageRecipient, outgoingMessageData);
+			if (!isMessageAlreadySent) {
+				PrivateKeyAccount sender = new PrivateKeyAccount(repository, tradeBotData.getTradePrivateKey());
+				MessageTransaction outgoingMessageTransaction = MessageTransaction.build(repository, sender, Group.NO_GROUP, messageRecipient, outgoingMessageData, false, false);
+
+				outgoingMessageTransaction.computeNonce();
+				outgoingMessageTransaction.sign(sender);
+
+				// reset repository state to prevent deadlock
+				repository.discardChanges();
+				ValidationResult result = outgoingMessageTransaction.importAsUnconfirmed();
+
+				if (result != ValidationResult.OK) {
+					LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: %s", messageRecipient, result.name()));
+					return;
+				}
+			}
+
+			TradeBot.updateTradeBotState(repository, tradeBotData, State.BOB_WAITING_FOR_AT_REDEEM,
+					() -> String.format("Locked AT %s to %s. Waiting for AT redeem", tradeBotData.getAtAddress(), aliceNativeAddress));
+
+			return;
+		}
+	}
+
+	/**
+	 * Trade-bot is waiting for Bob's AT to switch to TRADE mode and lock trade to Alice only.
+	 * <p>
+	 * It's possible that Bob has cancelled his trade offer in the mean time, or that somehow
+	 * this process has taken so long that we've reached P2SH-A's locktime, or that someone else
+	 * has managed to trade with Bob. In any of these cases, trade-bot switches to begin the refunding process.
+	 * <p>
+	 * Assuming Bob's AT is locked to Alice, trade-bot checks AT's state data to make sure it is correct.
+	 * <p>
+	 * If all is well, trade-bot then redeems AT using Alice's secret-A, releasing Bob's QORT to Alice.
+	 * <p>
+	 * In revealing a valid secret-A, Bob can then redeem the LTC funds from P2SH-A.
+	 * <p>
+	 * @throws ForeignBlockchainException
+	 */
+	private void handleAliceWaitingForAtLock(Repository repository, TradeBotData tradeBotData,
+			ATData atData, CrossChainTradeData crossChainTradeData) throws DataException, ForeignBlockchainException {
+		if (aliceUnexpectedState(repository, tradeBotData, atData, crossChainTradeData))
+			return;
+
+		Litecoin litecoin = Litecoin.getInstance();
+		int lockTimeA = tradeBotData.getLockTimeA();
+
+		// Refund P2SH-A if we've passed lockTime-A
+		if (NTP.getTime() >= lockTimeA * 1000L) {
+			byte[] redeemScriptA = BitcoinyHTLC.buildScript(tradeBotData.getTradeForeignPublicKeyHash(), lockTimeA, crossChainTradeData.creatorForeignPKH, tradeBotData.getHashOfSecret());
+			String p2shAddressA = litecoin.deriveP2shAddress(redeemScriptA);
+
+			long feeTimestamp = calcFeeTimestamp(lockTimeA, crossChainTradeData.tradeTimeout);
+			long p2shFee = Litecoin.getInstance().getP2shFee(feeTimestamp);
+			long minimumAmountA = crossChainTradeData.expectedForeignAmount + p2shFee;
+
+			BitcoinyHTLC.Status htlcStatusA = BitcoinyHTLC.determineHtlcStatus(litecoin.getBlockchainProvider(), p2shAddressA, minimumAmountA);
+
+			switch (htlcStatusA) {
+				case UNFUNDED:
+				case FUNDING_IN_PROGRESS:
+				case FUNDED:
+					break;
+
+				case REDEEM_IN_PROGRESS:
+				case REDEEMED:
+					// Already redeemed?
+					TradeBot.updateTradeBotState(repository, tradeBotData, State.ALICE_DONE,
+							() -> String.format("P2SH-A %s already spent? Assuming trade completed", p2shAddressA));
+					return;
+
+				case REFUND_IN_PROGRESS:
+				case REFUNDED:
+					TradeBot.updateTradeBotState(repository, tradeBotData, State.ALICE_REFUNDED,
+							() -> String.format("P2SH-A %s already refunded. Trade aborted", p2shAddressA));
+					return;
+
+			}
+
+			TradeBot.updateTradeBotState(repository, tradeBotData, State.ALICE_REFUNDING_A,
+					() -> atData.getIsFinished()
+					? String.format("AT %s cancelled. Refunding P2SH-A %s - aborting trade", tradeBotData.getAtAddress(), p2shAddressA)
+					: String.format("LockTime-A reached, refunding P2SH-A %s - aborting trade", p2shAddressA));
+
+			return;
+		}
+
+		// We're waiting for AT to be in TRADE mode
+		if (crossChainTradeData.mode != AcctMode.TRADING)
+			return;
+
+		// AT is in TRADE mode and locked to us as checked by aliceUnexpectedState() above
+
+		// Find our MESSAGE to AT from previous state
+		List<MessageTransactionData> messageTransactionsData = repository.getMessageRepository().getMessagesByParticipants(tradeBotData.getTradeNativePublicKey(),
+				crossChainTradeData.qortalCreatorTradeAddress, null, null, null);
+		if (messageTransactionsData == null || messageTransactionsData.isEmpty()) {
+			LOGGER.warn(() -> String.format("Unable to find our message to trade creator %s?", crossChainTradeData.qortalCreatorTradeAddress));
+			return;
+		}
+
+		long recipientMessageTimestamp = messageTransactionsData.get(0).getTimestamp();
+		int refundTimeout = LitecoinACCTv1.calcRefundTimeout(recipientMessageTimestamp, lockTimeA);
+
+		// Our calculated refundTimeout should match AT's refundTimeout
+		if (refundTimeout != crossChainTradeData.refundTimeout) {
+			LOGGER.debug(() -> String.format("Trade AT refundTimeout '%d' doesn't match our refundTimeout '%d'", crossChainTradeData.refundTimeout, refundTimeout));
+			// We'll eventually refund
+			return;
+		}
+
+		// We're good to redeem AT
+
+		// Send 'redeem' MESSAGE to AT using both secret
+		byte[] secretA = tradeBotData.getSecret();
+		String qortalReceivingAddress = Base58.encode(tradeBotData.getReceivingAccountInfo()); // Actually contains whole address, not just PKH
+		byte[] messageData = LitecoinACCTv1.buildRedeemMessage(secretA, qortalReceivingAddress);
+		String messageRecipient = tradeBotData.getAtAddress();
+
+		boolean isMessageAlreadySent = repository.getMessageRepository().exists(tradeBotData.getTradeNativePublicKey(), messageRecipient, messageData);
+		if (!isMessageAlreadySent) {
+			PrivateKeyAccount sender = new PrivateKeyAccount(repository, tradeBotData.getTradePrivateKey());
+			MessageTransaction messageTransaction = MessageTransaction.build(repository, sender, Group.NO_GROUP, messageRecipient, messageData, false, false);
+
+			messageTransaction.computeNonce();
+			messageTransaction.sign(sender);
+
+			// Reset repository state to prevent deadlock
+			repository.discardChanges();
+			ValidationResult result = messageTransaction.importAsUnconfirmed();
+
+			if (result != ValidationResult.OK) {
+				LOGGER.warn(() -> String.format("Unable to send MESSAGE to AT %s: %s", messageRecipient, result.name()));
+				return;
+			}
+		}
+
+		TradeBot.updateTradeBotState(repository, tradeBotData, State.ALICE_DONE,
+				() -> String.format("Redeeming AT %s. Funds should arrive at %s",
+						tradeBotData.getAtAddress(), qortalReceivingAddress));
+	}
+
+	/**
+	 * Trade-bot is waiting for Alice to redeem Bob's AT, thus revealing secret-A which is required to spend the LTC funds from P2SH-A.
+	 * <p>
+	 * It's possible that Bob's AT has reached its trading timeout and automatically refunded QORT back to Bob. In which case,
+	 * trade-bot is done with this specific trade and finalizes in refunded state.
+	 * <p>
+	 * Assuming trade-bot can extract a valid secret-A from Alice's MESSAGE then trade-bot uses that to redeem the LTC funds from P2SH-A
+	 * to Bob's 'foreign'/Litecoin trade legacy-format address, as derived from trade private key.
+	 * <p>
+	 * (This could potentially be 'improved' to send LTC to any address of Bob's choosing by changing the transaction output).
+	 * <p>
+	 * If trade-bot successfully broadcasts the transaction, then this specific trade is done.
+	 * @throws ForeignBlockchainException
+	 */
+	private void handleBobWaitingForAtRedeem(Repository repository, TradeBotData tradeBotData,
+			ATData atData, CrossChainTradeData crossChainTradeData) throws DataException, ForeignBlockchainException {
+		// AT should be 'finished' once Alice has redeemed QORT funds
+		if (!atData.getIsFinished())
+			// Not finished yet
+			return;
+
+		// If AT is not REDEEMED then something has gone wrong
+		if (crossChainTradeData.mode != AcctMode.REDEEMED) {
+			// Not redeemed so must be refunded/cancelled
+			TradeBot.updateTradeBotState(repository, tradeBotData, State.BOB_REFUNDED,
+					() -> String.format("AT %s has auto-refunded - trade aborted", tradeBotData.getAtAddress()));
+
+			return;
+		}
+
+		byte[] secretA = LitecoinACCTv1.findSecretA(repository, crossChainTradeData);
+		if (secretA == null) {
+			LOGGER.debug(() -> String.format("Unable to find secret-A from redeem message to AT %s?", tradeBotData.getAtAddress()));
+			return;
+		}
+
+		// Use secret-A to redeem P2SH-A
+
+		Litecoin litecoin = Litecoin.getInstance();
+
+		byte[] receivingAccountInfo = tradeBotData.getReceivingAccountInfo();
+		int lockTimeA = crossChainTradeData.lockTimeA;
+		byte[] redeemScriptA = BitcoinyHTLC.buildScript(crossChainTradeData.partnerForeignPKH, lockTimeA, crossChainTradeData.creatorForeignPKH, crossChainTradeData.hashOfSecretA);
+		String p2shAddressA = litecoin.deriveP2shAddress(redeemScriptA);
+
+		// Fee for redeem/refund is subtracted from P2SH-A balance.
+		long feeTimestamp = calcFeeTimestamp(lockTimeA, crossChainTradeData.tradeTimeout);
+		long p2shFee = Litecoin.getInstance().getP2shFee(feeTimestamp);
+		long minimumAmountA = crossChainTradeData.expectedForeignAmount + p2shFee;
+		BitcoinyHTLC.Status htlcStatusA = BitcoinyHTLC.determineHtlcStatus(litecoin.getBlockchainProvider(), p2shAddressA, minimumAmountA);
+
+		switch (htlcStatusA) {
+			case UNFUNDED:
+			case FUNDING_IN_PROGRESS:
+				// P2SH-A suddenly not funded? Our best bet at this point is to hope for AT auto-refund
+				return;
+
+			case REDEEM_IN_PROGRESS:
+			case REDEEMED:
+				// Double-check that we have redeemed P2SH-A...
+				break;
+
+			case REFUND_IN_PROGRESS:
+			case REFUNDED:
+				// Wait for AT to auto-refund
+				return;
+
+			case FUNDED: {
+				Coin redeemAmount = Coin.valueOf(crossChainTradeData.expectedForeignAmount);
+				ECKey redeemKey = ECKey.fromPrivate(tradeBotData.getTradePrivateKey());
+				List<TransactionOutput> fundingOutputs = litecoin.getUnspentOutputs(p2shAddressA);
+
+				Transaction p2shRedeemTransaction = BitcoinyHTLC.buildRedeemTransaction(litecoin.getNetworkParameters(), redeemAmount, redeemKey,
+						fundingOutputs, redeemScriptA, secretA, receivingAccountInfo);
+
+				litecoin.broadcastTransaction(p2shRedeemTransaction);
+				break;
+			}
+		}
+
+		String receivingAddress = litecoin.pkhToAddress(receivingAccountInfo);
+
+		TradeBot.updateTradeBotState(repository, tradeBotData, State.BOB_DONE,
+				() -> String.format("P2SH-A %s redeemed. Funds should arrive at %s", tradeBotData.getAtAddress(), receivingAddress));
+	}
+
+	/**
+	 * Trade-bot is attempting to refund P2SH-A.
+	 * @throws ForeignBlockchainException
+	 */
+	private void handleAliceRefundingP2shA(Repository repository, TradeBotData tradeBotData,
+			ATData atData, CrossChainTradeData crossChainTradeData) throws DataException, ForeignBlockchainException {
+		int lockTimeA = tradeBotData.getLockTimeA();
+
+		// We can't refund P2SH-A until lockTime-A has passed
+		if (NTP.getTime() <= lockTimeA * 1000L)
+			return;
+
+		Litecoin litecoin = Litecoin.getInstance();
+
+		// We can't refund P2SH-A until median block time has passed lockTime-A (see BIP113)
+		int medianBlockTime = litecoin.getMedianBlockTime();
+		if (medianBlockTime <= lockTimeA)
+			return;
+
+		byte[] redeemScriptA = BitcoinyHTLC.buildScript(tradeBotData.getTradeForeignPublicKeyHash(), lockTimeA, crossChainTradeData.creatorForeignPKH, tradeBotData.getHashOfSecret());
+		String p2shAddressA = litecoin.deriveP2shAddress(redeemScriptA);
+
+		// Fee for redeem/refund is subtracted from P2SH-A balance.
+		long feeTimestamp = calcFeeTimestamp(lockTimeA, crossChainTradeData.tradeTimeout);
+		long p2shFee = Litecoin.getInstance().getP2shFee(feeTimestamp);
+		long minimumAmountA = crossChainTradeData.expectedForeignAmount + p2shFee;
+		BitcoinyHTLC.Status htlcStatusA = BitcoinyHTLC.determineHtlcStatus(litecoin.getBlockchainProvider(), p2shAddressA, minimumAmountA);
+
+		switch (htlcStatusA) {
+			case UNFUNDED:
+			case FUNDING_IN_PROGRESS:
+				// Still waiting for P2SH-A to be funded...
+				return;
+
+			case REDEEM_IN_PROGRESS:
+			case REDEEMED:
+				// Too late!
+				TradeBot.updateTradeBotState(repository, tradeBotData, State.ALICE_DONE,
+						() -> String.format("P2SH-A %s already spent!", p2shAddressA));
+				return;
+
+			case REFUND_IN_PROGRESS:
+			case REFUNDED:
+				break;
+
+			case FUNDED:{
+				Coin refundAmount = Coin.valueOf(crossChainTradeData.expectedForeignAmount);
+				ECKey refundKey = ECKey.fromPrivate(tradeBotData.getTradePrivateKey());
+				List<TransactionOutput> fundingOutputs = litecoin.getUnspentOutputs(p2shAddressA);
+
+				// Determine receive address for refund
+				String receiveAddress = litecoin.getUnusedReceiveAddress(tradeBotData.getForeignKey());
+				Address receiving = Address.fromString(litecoin.getNetworkParameters(), receiveAddress);
+
+				Transaction p2shRefundTransaction = BitcoinyHTLC.buildRefundTransaction(litecoin.getNetworkParameters(), refundAmount, refundKey,
+						fundingOutputs, redeemScriptA, lockTimeA, receiving.getHash());
+
+				litecoin.broadcastTransaction(p2shRefundTransaction);
+				break;
+			}
+		}
+
+		TradeBot.updateTradeBotState(repository, tradeBotData, State.ALICE_REFUNDED,
+				() -> String.format("LockTime-A reached. Refunded P2SH-A %s. Trade aborted", p2shAddressA));
+	}
+
+	/**
+	 * Returns true if Alice finds AT unexpectedly cancelled, refunded, redeemed or locked to someone else.
+	 * <p>
+	 * Will automatically update trade-bot state to <tt>ALICE_REFUNDING_A</tt> or <tt>ALICE_DONE</tt> as necessary.
+	 * 
+	 * @throws DataException
+	 * @throws ForeignBlockchainException
+	 */
+	private boolean aliceUnexpectedState(Repository repository, TradeBotData tradeBotData,
+			ATData atData, CrossChainTradeData crossChainTradeData) throws DataException, ForeignBlockchainException {
+		// This is OK
+		if (!atData.getIsFinished() && crossChainTradeData.mode == AcctMode.OFFERING)
+			return false;
+
+		boolean isAtLockedToUs = tradeBotData.getTradeNativeAddress().equals(crossChainTradeData.qortalPartnerAddress);
+
+		if (!atData.getIsFinished() && crossChainTradeData.mode == AcctMode.TRADING)
+			if (isAtLockedToUs) {
+				// AT is trading with us - OK
+				return false;
+			} else {
+				TradeBot.updateTradeBotState(repository, tradeBotData, State.ALICE_REFUNDING_A,
+						() -> String.format("AT %s trading with someone else: %s. Refunding & aborting trade", tradeBotData.getAtAddress(), crossChainTradeData.qortalPartnerAddress));
+
+				return true;
+			}
+
+		if (atData.getIsFinished() && crossChainTradeData.mode == AcctMode.REDEEMED && isAtLockedToUs) {
+			// We've redeemed already?
+			TradeBot.updateTradeBotState(repository, tradeBotData, State.ALICE_DONE,
+					() -> String.format("AT %s already redeemed by us. Trade completed", tradeBotData.getAtAddress()));
+		} else {
+			// Any other state is not good, so start defensive refund
+			TradeBot.updateTradeBotState(repository, tradeBotData, State.ALICE_REFUNDING_A,
+					() -> String.format("AT %s cancelled/refunded/redeemed by someone else/invalid state. Refunding & aborting trade", tradeBotData.getAtAddress()));
+		}
+
+		return true;
+	}
+
+	private long calcFeeTimestamp(int lockTimeA, int tradeTimeout) {
+		return (lockTimeA - tradeTimeout * 60) * 1000L;
+	}
+
+}

src/main/java/org/qortal/controller/tradebot/TradeBot.java

@@ -0,0 +1,362 @@
+package org.qortal.controller.tradebot;
+
+import java.awt.TrayIcon.MessageType;
+import java.security.SecureRandom;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Random;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.apache.logging.log4j.util.Supplier;
+import org.bitcoinj.core.ECKey;
+import org.qortal.account.PrivateKeyAccount;
+import org.qortal.api.model.crosschain.TradeBotCreateRequest;
+import org.qortal.controller.Controller;
+import org.qortal.controller.tradebot.AcctTradeBot.ResponseResult;
+import org.qortal.crosschain.ACCT;
+import org.qortal.crosschain.BitcoinACCTv1;
+import org.qortal.crosschain.ForeignBlockchainException;
+import org.qortal.crosschain.LitecoinACCTv1;
+import org.qortal.crosschain.SupportedBlockchain;
+import org.qortal.data.at.ATData;
+import org.qortal.data.crosschain.CrossChainTradeData;
+import org.qortal.data.crosschain.TradeBotData;
+import org.qortal.data.transaction.BaseTransactionData;
+import org.qortal.data.transaction.PresenceTransactionData;
+import org.qortal.event.Event;
+import org.qortal.event.EventBus;
+import org.qortal.event.Listener;
+import org.qortal.group.Group;
+import org.qortal.gui.SysTray;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.repository.RepositoryManager;
+import org.qortal.settings.Settings;
+import org.qortal.transaction.PresenceTransaction;
+import org.qortal.transaction.PresenceTransaction.PresenceType;
+import org.qortal.transaction.Transaction.ValidationResult;
+import org.qortal.transform.transaction.TransactionTransformer;
+import org.qortal.utils.NTP;
+
+import com.google.common.primitives.Longs;
+
+/**
+ * Performing cross-chain trading steps on behalf of user.
+ * <p>
+ * We deal with three different independent state-spaces here:
+ * <ul>
+ * 	<li>Qortal blockchain</li>
+ * 	<li>Foreign blockchain</li>
+ * 	<li>Trade-bot entries</li>
+ * </ul>
+ */
+public class TradeBot implements Listener {
+
+	private static final Logger LOGGER = LogManager.getLogger(TradeBot.class);
+	private static final Random RANDOM = new SecureRandom();
+
+	public interface StateNameAndValueSupplier {
+		public String getState();
+		public int getStateValue();
+	}
+
+	public static class StateChangeEvent implements Event {
+		private final TradeBotData tradeBotData;
+
+		public StateChangeEvent(TradeBotData tradeBotData) {
+			this.tradeBotData = tradeBotData;
+		}
+
+		public TradeBotData getTradeBotData() {
+			return this.tradeBotData;
+		}
+	}
+
+	private static final Map<Class<? extends ACCT>, Supplier<AcctTradeBot>> acctTradeBotSuppliers = new HashMap<>();
+	static {
+		acctTradeBotSuppliers.put(BitcoinACCTv1.class, BitcoinACCTv1TradeBot::getInstance);
+		acctTradeBotSuppliers.put(LitecoinACCTv1.class, LitecoinACCTv1TradeBot::getInstance);
+	}
+
+	private static TradeBot instance;
+
+	private final Map<String, Long> presenceTimestampsByAtAddress = Collections.synchronizedMap(new HashMap<>());
+
+	private TradeBot() {
+		EventBus.INSTANCE.addListener(event -> TradeBot.getInstance().listen(event));
+	}
+
+	public static synchronized TradeBot getInstance() {
+		if (instance == null)
+			instance = new TradeBot();
+
+		return instance;
+	}
+
+	public ACCT getAcctUsingAtData(ATData atData) {
+		byte[] codeHash = atData.getCodeHash();
+		if (codeHash == null)
+			return null;
+
+		return SupportedBlockchain.getAcctByCodeHash(codeHash);
+	}
+
+	public CrossChainTradeData populateTradeData(Repository repository, ATData atData) throws DataException {
+		ACCT acct = this.getAcctUsingAtData(atData);
+		if (acct == null)
+			return null;
+
+		return acct.populateTradeData(repository, atData);
+	}
+
+	/**
+	 * Creates a new trade-bot entry from the "Bob" viewpoint,
+	 * i.e. OFFERing QORT in exchange for foreign blockchain currency.
+	 * <p>
+	 * Generates:
+	 * <ul>
+	 * 	<li>new 'trade' private key</li>
+	 * 	<li>secret(s)</li>
+	 * </ul>
+	 * Derives:
+	 * <ul>
+	 * 	<li>'native' (as in Qortal) public key, public key hash, address (starting with Q)</li>
+	 * 	<li>'foreign' public key, public key hash</li>
+	 *	<li>hash(es) of secret(s)</li>
+	 * </ul>
+	 * A Qortal AT is then constructed including the following as constants in the 'data segment':
+	 * <ul>
+	 * 	<li>'native' (Qortal) 'trade' address - used to MESSAGE AT</li>
+	 * 	<li>'foreign' public key hash - used by Alice's to allow redeem of currency on foreign blockchain</li>
+	 * 	<li>hash(es) of secret(s) - used by AT (optional) and foreign blockchain as needed</li>
+	 * 	<li>QORT amount on offer by Bob</li>
+	 * 	<li>foreign currency amount expected in return by Bob (from Alice)</li>
+	 * 	<li>trading timeout, in case things go wrong and everyone needs to refund</li>
+	 * </ul>
+	 * Returns a DEPLOY_AT transaction that needs to be signed and broadcast to the Qortal network.
+	 * <p>
+	 * Trade-bot will wait for Bob's AT to be deployed before taking next step.
+	 * <p>
+	 * @param repository
+	 * @param tradeBotCreateRequest
+	 * @return raw, unsigned DEPLOY_AT transaction
+	 * @throws DataException
+	 */
+	public byte[] createTrade(Repository repository, TradeBotCreateRequest tradeBotCreateRequest) throws DataException {
+		// Fetch latest ACCT version for requested foreign blockchain
+		ACCT acct = tradeBotCreateRequest.foreignBlockchain.getLatestAcct();
+
+		AcctTradeBot acctTradeBot = findTradeBotForAcct(acct);
+		if (acctTradeBot == null)
+			return null;
+
+		return acctTradeBot.createTrade(repository, tradeBotCreateRequest);
+	}
+
+	/**
+	 * Creates a trade-bot entry from the 'Alice' viewpoint,
+	 * i.e. matching foreign blockchain currency to an existing QORT offer.
+	 * <p>
+	 * Requires a chosen trade offer from Bob, passed by <tt>crossChainTradeData</tt>
+	 * and access to a foreign blockchain wallet via <tt>foreignKey</tt>.
+	 * <p>
+	 * @param repository
+	 * @param crossChainTradeData chosen trade OFFER that Alice wants to match
+	 * @param foreignKey foreign blockchain wallet key
+	 * @throws DataException
+	 */
+	public ResponseResult startResponse(Repository repository, ATData atData, ACCT acct,
+			CrossChainTradeData crossChainTradeData, String foreignKey, String receivingAddress) throws DataException {
+		AcctTradeBot acctTradeBot = findTradeBotForAcct(acct);
+		if (acctTradeBot == null) {
+			LOGGER.debug(() -> String.format("Couldn't find ACCT trade-bot for AT %s", atData.getATAddress()));
+			return ResponseResult.NETWORK_ISSUE;
+		}
+
+		// Check Alice doesn't already have an existing, on-going trade-bot entry for this AT.
+		if (repository.getCrossChainRepository().existsTradeWithAtExcludingStates(atData.getATAddress(), acctTradeBot.getEndStates()))
+			return ResponseResult.TRADE_ALREADY_EXISTS;
+
+		return acctTradeBot.startResponse(repository, atData, acct, crossChainTradeData, foreignKey, receivingAddress);
+	}
+
+	public boolean deleteEntry(Repository repository, byte[] tradePrivateKey) throws DataException {
+		TradeBotData tradeBotData = repository.getCrossChainRepository().getTradeBotData(tradePrivateKey);
+		if (tradeBotData == null)
+			// Can't delete what we don't have!
+			return false;
+
+		boolean canDelete = false;
+
+		ACCT acct = SupportedBlockchain.getAcctByName(tradeBotData.getAcctName());
+		if (acct == null)
+			// We can't/no longer support this ACCT
+			canDelete = true;
+		else {
+			AcctTradeBot acctTradeBot = findTradeBotForAcct(acct);
+			canDelete = acctTradeBot == null || acctTradeBot.canDelete(repository, tradeBotData);
+		}
+
+		if (canDelete) {
+			repository.getCrossChainRepository().delete(tradePrivateKey);
+			repository.saveChanges();
+		}
+
+		return canDelete;
+	}
+
+	@Override
+	public void listen(Event event) {
+		if (!(event instanceof Controller.NewBlockEvent))
+			return;
+
+		synchronized (this) {
+			List<TradeBotData> allTradeBotData;
+
+			try (final Repository repository = RepositoryManager.getRepository()) {
+				allTradeBotData = repository.getCrossChainRepository().getAllTradeBotData();
+			} catch (DataException e) {
+				LOGGER.error("Couldn't run trade bot due to repository issue", e);
+				return;
+			}
+
+			for (TradeBotData tradeBotData : allTradeBotData)
+				try (final Repository repository = RepositoryManager.getRepository()) {
+					// Find ACCT-specific trade-bot for this entry
+					ACCT acct = SupportedBlockchain.getAcctByName(tradeBotData.getAcctName());
+					if (acct == null) {
+						LOGGER.debug(() -> String.format("Couldn't find ACCT matching name %s", tradeBotData.getAcctName()));
+						continue;
+					}
+
+					AcctTradeBot acctTradeBot = findTradeBotForAcct(acct);
+					if (acctTradeBot == null) {
+						LOGGER.debug(() -> String.format("Couldn't find ACCT trade-bot matching name %s", tradeBotData.getAcctName()));
+						continue;
+					}
+
+					acctTradeBot.progress(repository, tradeBotData);
+				} catch (DataException e) {
+					LOGGER.error("Couldn't run trade bot due to repository issue", e);
+				} catch (ForeignBlockchainException e) {
+					LOGGER.warn(() -> String.format("Foreign blockchain issue processing trade-bot entry for AT %s: %s", tradeBotData.getAtAddress(), e.getMessage()));
+				}
+		}
+	}
+
+	/*package*/ static byte[] generateTradePrivateKey() {
+		// The private key is used for both Curve25519 and secp256k1 so needs to be valid for both.
+		// Curve25519 accepts any seed, so generate a valid secp256k1 key and use that.
+		return new ECKey().getPrivKeyBytes();
+	}
+
+	/*package*/ static byte[] deriveTradeNativePublicKey(byte[] privateKey) {
+		return PrivateKeyAccount.toPublicKey(privateKey);
+	}
+
+	/*package*/ static byte[] deriveTradeForeignPublicKey(byte[] privateKey) {
+		return ECKey.fromPrivate(privateKey).getPubKey();
+	}
+
+	/*package*/ static byte[] generateSecret() {
+		byte[] secret = new byte[32];
+		RANDOM.nextBytes(secret);
+		return secret;
+	}
+
+	/** Updates trade-bot entry to new state, with current timestamp, logs message and notifies state-change listeners. */
+	/*package*/ static void updateTradeBotState(Repository repository, TradeBotData tradeBotData,
+			String newState, int newStateValue, Supplier<String> logMessageSupplier) throws DataException {
+		tradeBotData.setState(newState);
+		tradeBotData.setStateValue(newStateValue);
+		tradeBotData.setTimestamp(NTP.getTime());
+		repository.getCrossChainRepository().save(tradeBotData);
+		repository.saveChanges();
+
+		if (Settings.getInstance().isTradebotSystrayEnabled())
+			SysTray.getInstance().showMessage("Trade-Bot", String.format("%s: %s", tradeBotData.getAtAddress(), newState), MessageType.INFO);
+
+		if (logMessageSupplier != null)
+			LOGGER.info(logMessageSupplier);
+
+		LOGGER.debug(() -> String.format("new state for trade-bot entry based on AT %s: %s", tradeBotData.getAtAddress(), newState));
+
+		notifyStateChange(tradeBotData);
+	}
+
+	/** Updates trade-bot entry to new state, with current timestamp, logs message and notifies state-change listeners. */
+	/*package*/ static void updateTradeBotState(Repository repository, TradeBotData tradeBotData, StateNameAndValueSupplier newStateSupplier, Supplier<String> logMessageSupplier) throws DataException {
+		updateTradeBotState(repository, tradeBotData, newStateSupplier.getState(), newStateSupplier.getStateValue(), logMessageSupplier);
+	}
+
+	/** Updates trade-bot entry to new state, with current timestamp, logs message and notifies state-change listeners. */
+	/*package*/ static void updateTradeBotState(Repository repository, TradeBotData tradeBotData, Supplier<String> logMessageSupplier) throws DataException {
+		updateTradeBotState(repository, tradeBotData, tradeBotData.getState(), tradeBotData.getStateValue(), logMessageSupplier);
+	}
+
+	/*package*/ static void notifyStateChange(TradeBotData tradeBotData) {
+		StateChangeEvent stateChangeEvent = new StateChangeEvent(tradeBotData);
+		EventBus.INSTANCE.notify(stateChangeEvent);
+	}
+
+	/*package*/ static AcctTradeBot findTradeBotForAcct(ACCT acct) {
+		Supplier<AcctTradeBot> acctTradeBotSupplier = acctTradeBotSuppliers.get(acct.getClass());
+		if (acctTradeBotSupplier == null)
+			return null;
+
+		return acctTradeBotSupplier.get();
+	}
+
+	// PRESENCE-related
+	/*package*/ void updatePresence(Repository repository, TradeBotData tradeBotData, CrossChainTradeData tradeData)
+			throws DataException {
+		String atAddress = tradeBotData.getAtAddress();
+
+		PrivateKeyAccount tradeNativeAccount = new PrivateKeyAccount(repository, tradeBotData.getTradePrivateKey());
+		String signerAddress = tradeNativeAccount.getAddress();
+
+		/*
+		 * There's no point in Alice trying to build a PRESENCE transaction
+		 * for an AT that isn't locked to her, as other peers won't be able
+		 * to validate the PRESENCE transaction as signing public key won't
+		 * be visible.
+		 */
+		if (!signerAddress.equals(tradeData.qortalCreatorTradeAddress) && !signerAddress.equals(tradeData.qortalPartnerAddress))
+			// Signer is neither Bob, nor Alice, or trade not yet locked to Alice
+			return;
+
+		long now = NTP.getTime();
+		long threshold = now - PresenceType.TRADE_BOT.getLifetime();
+
+		long timestamp = presenceTimestampsByAtAddress.compute(atAddress, (k, v) -> (v == null || v < threshold) ? now : v);
+
+		// If timestamp hasn't been updated then nothing to do
+		if (timestamp != now)
+			return;
+
+		int txGroupId = Group.NO_GROUP;
+		byte[] reference = new byte[TransactionTransformer.SIGNATURE_LENGTH];
+		byte[] creatorPublicKey = tradeNativeAccount.getPublicKey();
+		long fee = 0L;
+
+		BaseTransactionData baseTransactionData = new BaseTransactionData(timestamp, txGroupId, reference, creatorPublicKey, fee, null);
+
+		int nonce = 0;
+		byte[] timestampSignature = tradeNativeAccount.sign(Longs.toByteArray(timestamp));
+
+		PresenceTransactionData transactionData = new PresenceTransactionData(baseTransactionData, nonce, PresenceType.TRADE_BOT, timestampSignature);
+
+		PresenceTransaction presenceTransaction = new PresenceTransaction(repository, transactionData);
+		presenceTransaction.computeNonce();
+
+		presenceTransaction.sign(tradeNativeAccount);
+
+		ValidationResult result = presenceTransaction.importAsUnconfirmed();
+		if (result != ValidationResult.OK)
+			LOGGER.debug(() -> String.format("Unable to build trade-bot PRESENCE transaction for %s: %s", tradeBotData.getAtAddress(), result.name()));
+	}
+
+}

src/main/java/org/qortal/crosschain/ACCT.java

@@ -0,0 +1,23 @@
+package org.qortal.crosschain;
+
+import org.qortal.data.at.ATData;
+import org.qortal.data.at.ATStateData;
+import org.qortal.data.crosschain.CrossChainTradeData;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+
+public interface ACCT {
+
+	public byte[] getCodeBytesHash();
+
+	public int getModeByteOffset();
+
+	public ForeignBlockchain getBlockchain();
+
+	public CrossChainTradeData populateTradeData(Repository repository, ATData atData) throws DataException;
+
+	public CrossChainTradeData populateTradeData(Repository repository, ATStateData atStateData) throws DataException;
+
+	public byte[] buildCancelMessage(String creatorQortalAddress);
+
+}

src/main/java/org/qortal/crosschain/AcctMode.java

@@ -0,0 +1,21 @@
+package org.qortal.crosschain;
+
+import static java.util.Arrays.stream;
+import static java.util.stream.Collectors.toMap;
+
+import java.util.Map;
+
+public enum AcctMode {
+	OFFERING(0), TRADING(1), CANCELLED(2), REFUNDED(3), REDEEMED(4);
+
+	public final int value;
+	private static final Map<Integer, AcctMode> map = stream(AcctMode.values()).collect(toMap(mode -> mode.value, mode -> mode));
+
+	AcctMode(int value) {
+		this.value = value;
+	}
+
+	public static AcctMode valueOf(int value) {
+		return map.get(value);
+	}
+}

src/main/java/org/qortal/crosschain/BTC.java

@@ -1,559 +0,0 @@
-package org.qortal.crosschain;
-
-import java.util.ArrayList;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Set;
-import java.util.stream.Collectors;
-
-import org.apache.logging.log4j.LogManager;
-import org.apache.logging.log4j.Logger;
-import org.bitcoinj.core.Address;
-import org.bitcoinj.core.Coin;
-import org.bitcoinj.core.Context;
-import org.bitcoinj.core.ECKey;
-import org.bitcoinj.core.InsufficientMoneyException;
-import org.bitcoinj.core.LegacyAddress;
-import org.bitcoinj.core.NetworkParameters;
-import org.bitcoinj.core.Sha256Hash;
-import org.bitcoinj.core.Transaction;
-import org.bitcoinj.core.TransactionOutput;
-import org.bitcoinj.core.UTXO;
-import org.bitcoinj.core.UTXOProvider;
-import org.bitcoinj.core.UTXOProviderException;
-import org.bitcoinj.crypto.ChildNumber;
-import org.bitcoinj.crypto.DeterministicHierarchy;
-import org.bitcoinj.crypto.DeterministicKey;
-import org.bitcoinj.params.MainNetParams;
-import org.bitcoinj.params.RegTestParams;
-import org.bitcoinj.params.TestNet3Params;
-import org.bitcoinj.script.Script.ScriptType;
-import org.bitcoinj.script.ScriptBuilder;
-import org.bitcoinj.utils.MonetaryFormat;
-import org.bitcoinj.wallet.DeterministicKeyChain;
-import org.bitcoinj.wallet.SendRequest;
-import org.bitcoinj.wallet.Wallet;
-import org.qortal.crypto.Crypto;
-import org.qortal.settings.Settings;
-import org.qortal.utils.BitTwiddling;
-
-import com.google.common.hash.HashCode;
-
-public class BTC {
-
-	public static final long NO_LOCKTIME_NO_RBF_SEQUENCE = 0xFFFFFFFFL;
-	public static final long LOCKTIME_NO_RBF_SEQUENCE = NO_LOCKTIME_NO_RBF_SEQUENCE - 1;
-	public static final int HASH160_LENGTH = 20;
-
-	public static final boolean INCLUDE_UNCONFIRMED = true;
-	public static final boolean EXCLUDE_UNCONFIRMED = false;
-
-	protected static final Logger LOGGER = LogManager.getLogger(BTC.class);
-
-	// Temporary values until a dynamic fee system is written.
-	private static final long OLD_FEE_AMOUNT = 4_000L; // Not 5000 so that existing P2SH-B can output 1000, avoiding dust issue, leaving 4000 for fees.
-	private static final long NEW_FEE_TIMESTAMP = 1598280000000L; // milliseconds since epoch
-	private static final long NEW_FEE_AMOUNT = 10_000L;
-	private static final long NON_MAINNET_FEE = 1000L; // enough for TESTNET3 and should be OK for REGTEST
-
-	private static final int TIMESTAMP_OFFSET = 4 + 32 + 32;
-	private static final MonetaryFormat FORMAT = new MonetaryFormat().minDecimals(8).postfixCode();
-
-	public enum BitcoinNet {
-		MAIN {
-			@Override
-			public NetworkParameters getParams() {
-				return MainNetParams.get();
-			}
-		},
-		TEST3 {
-			@Override
-			public NetworkParameters getParams() {
-				return TestNet3Params.get();
-			}
-		},
-		REGTEST {
-			@Override
-			public NetworkParameters getParams() {
-				return RegTestParams.get();
-			}
-		};
-
-		public abstract NetworkParameters getParams();
-	}
-
-	private static BTC instance;
-	private final NetworkParameters params;
-	private final ElectrumX electrumX;
-	private final Context bitcoinjContext;
-
-	// Let ECKey.equals() do the hard work
-	private final Set<ECKey> spentKeys = new HashSet<>();
-
-	// Constructors and instance
-
-	private BTC() {
-		BitcoinNet bitcoinNet = Settings.getInstance().getBitcoinNet();
-		this.params = bitcoinNet.getParams();
-
-		LOGGER.info(() -> String.format("Starting Bitcoin support using %s", bitcoinNet.name()));
-
-		this.electrumX = ElectrumX.getInstance(bitcoinNet.name());
-		this.bitcoinjContext = new Context(this.params);
-	}
-
-	public static synchronized BTC getInstance() {
-		if (instance == null)
-			instance = new BTC();
-
-		return instance;
-	}
-
-	// Getters & setters
-
-	public NetworkParameters getNetworkParameters() {
-		return this.params;
-	}
-
-	public static synchronized void resetForTesting() {
-		instance = null;
-	}
-
-	// Actual useful methods for use by other classes
-
-	public static String format(Coin amount) {
-		return BTC.FORMAT.format(amount).toString();
-	}
-
-	public static String format(long amount) {
-		return format(Coin.valueOf(amount));
-	}
-
-	public boolean isValidXprv(String xprv58) {
-		try {
-			Context.propagate(bitcoinjContext);
-			DeterministicKey.deserializeB58(null, xprv58, this.params);
-			return true;
-		} catch (IllegalArgumentException e) {
-			return false;
-		}
-	}
-
-	/** Returns P2PKH Bitcoin address using passed public key hash. */
-	public String pkhToAddress(byte[] publicKeyHash) {
-		Context.propagate(bitcoinjContext);
-		return LegacyAddress.fromPubKeyHash(this.params, publicKeyHash).toString();
-	}
-
-	public String deriveP2shAddress(byte[] redeemScriptBytes) {
-		byte[] redeemScriptHash = Crypto.hash160(redeemScriptBytes);
-		Context.propagate(bitcoinjContext);
-		Address p2shAddress = LegacyAddress.fromScriptHash(params, redeemScriptHash);
-		return p2shAddress.toString();
-	}
-
-	/**
-	 * Returns median timestamp from latest 11 blocks, in seconds.
-	 * <p>
-	 * @throws BitcoinException if error occurs
-	 */
-	public Integer getMedianBlockTime() throws BitcoinException {
-		int height = this.electrumX.getCurrentHeight();
-
-		// Grab latest 11 blocks
-		List<byte[]> blockHeaders = this.electrumX.getBlockHeaders(height - 11, 11);
-		if (blockHeaders.size() < 11)
-			throw new BitcoinException("Not enough blocks to determine median block time");
-
-		List<Integer> blockTimestamps = blockHeaders.stream().map(blockHeader -> BitTwiddling.intFromLEBytes(blockHeader, TIMESTAMP_OFFSET)).collect(Collectors.toList());
-
-		// Descending order
-		blockTimestamps.sort((a, b) -> Integer.compare(b, a));
-
-		// Pick median
-		return blockTimestamps.get(5);
-	}
-
-	/**
-	 * Returns estimated BTC fee, in sats per 1000bytes, optionally for historic timestamp.
-	 * 
-	 * @param timestamp optional milliseconds since epoch, or null for 'now'
-	 * @return sats per 1000bytes, or throws BitcoinException if something went wrong
-	 */
-	public long estimateFee(Long timestamp) throws BitcoinException {
-		if (!this.params.getId().equals(NetworkParameters.ID_MAINNET))
-			return NON_MAINNET_FEE;
-
-		// TODO: This will need to be replaced with something better in the near future!
-		if (timestamp != null && timestamp < NEW_FEE_TIMESTAMP)
-			return OLD_FEE_AMOUNT;
-
-		return NEW_FEE_AMOUNT;
-	}
-
-	/**
-	 * Returns confirmed balance, based on passed payment script.
-	 * <p>
-	 * @return confirmed balance, or zero if script unknown
-	 * @throws BitcoinException if there was an error
-	 */
-	public long getConfirmedBalance(String base58Address) throws BitcoinException {
-		return this.electrumX.getConfirmedBalance(addressToScript(base58Address));
-	}
-
-	/**
-	 * Returns list of unspent outputs pertaining to passed address.
-	 * <p>
-	 * @return list of unspent outputs, or empty list if address unknown
-	 * @throws BitcoinException if there was an error.
-	 */
-	public List<TransactionOutput> getUnspentOutputs(String base58Address) throws BitcoinException {
-		List<UnspentOutput> unspentOutputs = this.electrumX.getUnspentOutputs(addressToScript(base58Address), false);
-
-		List<TransactionOutput> unspentTransactionOutputs = new ArrayList<>();
-		for (UnspentOutput unspentOutput : unspentOutputs) {
-			List<TransactionOutput> transactionOutputs = this.getOutputs(unspentOutput.hash);
-
-			unspentTransactionOutputs.add(transactionOutputs.get(unspentOutput.index));
-		}
-
-		return unspentTransactionOutputs;
-	}
-
-	/**
-	 * Returns list of outputs pertaining to passed transaction hash.
-	 * <p>
-	 * @return list of outputs, or empty list if transaction unknown
-	 * @throws BitcoinException if there was an error.
-	 */
-	public List<TransactionOutput> getOutputs(byte[] txHash) throws BitcoinException {
-		byte[] rawTransactionBytes = this.electrumX.getRawTransaction(txHash);
-
-		// XXX bitcoinj: replace with getTransaction() below
-		Context.propagate(bitcoinjContext);
-		Transaction transaction = new Transaction(this.params, rawTransactionBytes);
-		return transaction.getOutputs();
-	}
-
-	/**
-	 * Returns list of transaction hashes pertaining to passed address.
-	 * <p>
-	 * @return list of unspent outputs, or empty list if script unknown
-	 * @throws BitcoinException if there was an error.
-	 */
-	public List<TransactionHash> getAddressTransactions(String base58Address, boolean includeUnconfirmed) throws BitcoinException {
-		return this.electrumX.getAddressTransactions(addressToScript(base58Address), includeUnconfirmed);
-	}
-
-	/**
-	 * Returns list of raw, confirmed transactions involving given address.
-	 * <p>
-	 * @throws BitcoinException if there was an error
-	 */
-	public List<byte[]> getAddressTransactions(String base58Address) throws BitcoinException {
-		List<TransactionHash> transactionHashes = this.electrumX.getAddressTransactions(addressToScript(base58Address), false);
-
-		List<byte[]> rawTransactions = new ArrayList<>();
-		for (TransactionHash transactionInfo : transactionHashes) {
-			byte[] rawTransaction = this.electrumX.getRawTransaction(HashCode.fromString(transactionInfo.txHash).asBytes());
-			rawTransactions.add(rawTransaction);
-		}
-
-		return rawTransactions;
-	}
-
-	/**
-	 * Returns transaction info for passed transaction hash.
-	 * <p>
-	 * @throws BitcoinException.NotFoundException if transaction unknown
-	 * @throws BitcoinException if error occurs
-	 */
-	public BitcoinTransaction getTransaction(String txHash) throws BitcoinException {
-		return this.electrumX.getTransaction(txHash);
-	}
-
-	/**
-	 * Broadcasts raw transaction to Bitcoin network.
-	 * <p>
-	 * @throws BitcoinException if error occurs
-	 */
-	public void broadcastTransaction(Transaction transaction) throws BitcoinException {
-		this.electrumX.broadcastTransaction(transaction.bitcoinSerialize());
-	}
-
-	/**
-	 * Returns bitcoinj transaction sending <tt>amount</tt> to <tt>recipient</tt>.
-	 * 
-	 * @param xprv58 BIP32 extended Bitcoin private key
-	 * @param recipient P2PKH address
-	 * @param amount unscaled amount
-	 * @return transaction, or null if insufficient funds
-	 */
-	public Transaction buildSpend(String xprv58, String recipient, long amount) {
-		Context.propagate(bitcoinjContext);
-		Wallet wallet = Wallet.fromSpendingKeyB58(this.params, xprv58, DeterministicHierarchy.BIP32_STANDARDISATION_TIME_SECS);
-		wallet.setUTXOProvider(new WalletAwareUTXOProvider(this, wallet, WalletAwareUTXOProvider.KeySearchMode.REQUEST_MORE_IF_ANY_SPENT));
-
-		Address destination = Address.fromString(this.params, recipient);
-		SendRequest sendRequest = SendRequest.to(destination, Coin.valueOf(amount));
-
-		if (this.params == TestNet3Params.get())
-			// Much smaller fee for TestNet3
-			sendRequest.feePerKb = Coin.valueOf(2000L);
-
-		try {
-			wallet.completeTx(sendRequest);
-			return sendRequest.tx;
-		} catch (InsufficientMoneyException e) {
-			return null;
-		}
-	}
-
-	/**
-	 * Returns unspent Bitcoin balance given 'm' BIP32 key.
-	 *
-	 * @param xprv58 BIP32 extended Bitcoin private key
-	 * @return unspent BTC balance, or null if unable to determine balance
-	 */
-	public Long getWalletBalance(String xprv58) {
-		Context.propagate(bitcoinjContext);
-		Wallet wallet = Wallet.fromSpendingKeyB58(this.params, xprv58, DeterministicHierarchy.BIP32_STANDARDISATION_TIME_SECS);
-		wallet.setUTXOProvider(new WalletAwareUTXOProvider(this, wallet, WalletAwareUTXOProvider.KeySearchMode.REQUEST_MORE_IF_ANY_SPENT));
-
-		Coin balance = wallet.getBalance();
-		if (balance == null)
-			return null;
-
-		return balance.value;
-	}
-
-	/**
-	 * Returns first unused receive address given 'm' BIP32 key.
-	 *
-	 * @param xprv58 BIP32 extended Bitcoin private key
-	 * @return Bitcoin P2PKH address
-	 * @throws BitcoinException if something went wrong
-	 */
-	public String getUnusedReceiveAddress(String xprv58) throws BitcoinException {
-		Context.propagate(bitcoinjContext);
-		Wallet wallet = Wallet.fromSpendingKeyB58(this.params, xprv58, DeterministicHierarchy.BIP32_STANDARDISATION_TIME_SECS);
-		DeterministicKeyChain keyChain = wallet.getActiveKeyChain();
-
-		keyChain.setLookaheadSize(WalletAwareUTXOProvider.LOOKAHEAD_INCREMENT);
-		keyChain.maybeLookAhead();
-
-		final int keyChainPathSize = keyChain.getAccountPath().size();
-		List<DeterministicKey> keys = new ArrayList<>(keyChain.getLeafKeys());
-
-		int ki = 0;
-		do {
-			for (; ki < keys.size(); ++ki) {
-				DeterministicKey dKey = keys.get(ki);
-				List<ChildNumber> dKeyPath = dKey.getPath();
-
-				// If keyChain is based on 'm', then make sure dKey is m/0/ki
-				if (dKeyPath.size() != keyChainPathSize + 2 || dKeyPath.get(dKeyPath.size() - 2) != ChildNumber.ZERO)
-					continue;
-
-				// Check unspent
-				Address address = Address.fromKey(this.params, dKey, ScriptType.P2PKH);
-				byte[] script = ScriptBuilder.createOutputScript(address).getProgram();
-
-				List<UnspentOutput> unspentOutputs = this.electrumX.getUnspentOutputs(script, false);
-
-				/*
-				 * If there are no unspent outputs then either:
-				 * a) all the outputs have been spent
-				 * b) address has never been used
-				 * 
-				 * For case (a) we want to remember not to check this address (key) again.
-				 */
-
-				if (unspentOutputs.isEmpty()) {
-					// If this is a known key that has been spent before, then we can skip asking for transaction history
-					if (this.spentKeys.contains(dKey)) {
-						wallet.getActiveKeyChain().markKeyAsUsed((DeterministicKey) dKey);
-						continue;
-					}
-
-					// Ask for transaction history - if it's empty then key has never been used
-					List<TransactionHash> historicTransactionHashes = this.electrumX.getAddressTransactions(script, false);
-
-					if (!historicTransactionHashes.isEmpty()) {
-						// Fully spent key - case (a)
-						this.spentKeys.add(dKey);
-						wallet.getActiveKeyChain().markKeyAsUsed(dKey);
-					} else {
-						// Key never been used - case (b)
-						return address.toString();
-					}
-				}
-
-				// Key has unspent outputs, hence used, so no good to us
-				this.spentKeys.remove(dKey);
-			}
-
-			// Generate some more keys
-			keyChain.setLookaheadSize(keyChain.getLookaheadSize() + WalletAwareUTXOProvider.LOOKAHEAD_INCREMENT);
-			keyChain.maybeLookAhead();
-
-			// This returns all keys, including those already in 'keys'
-			List<DeterministicKey> allLeafKeys = keyChain.getLeafKeys();
-			// Add only new keys onto our list of keys to search
-			List<DeterministicKey> newKeys = allLeafKeys.subList(ki, allLeafKeys.size());
-			keys.addAll(newKeys);
-			// Fall-through to checking more keys as now 'ki' is smaller than 'keys.size()' again
-
-			// Process new keys
-		} while (true);
-	}
-
-	// UTXOProvider support
-
-	static class WalletAwareUTXOProvider implements UTXOProvider {
-		private static final int LOOKAHEAD_INCREMENT = 3;
-
-		private final BTC btc;
-		private final Wallet wallet;
-
-		enum KeySearchMode {
-			REQUEST_MORE_IF_ALL_SPENT, REQUEST_MORE_IF_ANY_SPENT;
-		}
-		private final KeySearchMode keySearchMode;
-		private final DeterministicKeyChain keyChain;
-
-		public WalletAwareUTXOProvider(BTC btc, Wallet wallet, KeySearchMode keySearchMode) {
-			this.btc = btc;
-			this.wallet = wallet;
-			this.keySearchMode = keySearchMode;
-			this.keyChain = this.wallet.getActiveKeyChain();
-
-			// Set up wallet's key chain
-			this.keyChain.setLookaheadSize(LOOKAHEAD_INCREMENT);
-			this.keyChain.maybeLookAhead();
-		}
-
-		public List<UTXO> getOpenTransactionOutputs(List<ECKey> keys) throws UTXOProviderException {
-			List<UTXO> allUnspentOutputs = new ArrayList<>();
-			final boolean coinbase = false;
-
-			int ki = 0;
-			do {
-				boolean areAllKeysUnspent = true;
-				boolean areAllKeysSpent = true;
-
-				for (; ki < keys.size(); ++ki) {
-					ECKey key = keys.get(ki);
-
-					Address address = Address.fromKey(btc.params, key, ScriptType.P2PKH);
-					byte[] script = ScriptBuilder.createOutputScript(address).getProgram();
-
-					List<UnspentOutput> unspentOutputs;
-					try {
-						unspentOutputs = btc.electrumX.getUnspentOutputs(script, false);
-					} catch (BitcoinException e) {
-						throw new UTXOProviderException(String.format("Unable to fetch unspent outputs for %s", address));
-					}
-
-					/*
-					 * If there are no unspent outputs then either:
-					 * a) all the outputs have been spent
-					 * b) address has never been used
-					 * 
-					 * For case (a) we want to remember not to check this address (key) again.
-					 */
-
-					if (unspentOutputs.isEmpty()) {
-						// If this is a known key that has been spent before, then we can skip asking for transaction history
-						if (btc.spentKeys.contains(key)) {
-							wallet.getActiveKeyChain().markKeyAsUsed((DeterministicKey) key);
-							areAllKeysUnspent = false;
-							continue;
-						}
-
-						// Ask for transaction history - if it's empty then key has never been used
-						List<TransactionHash> historicTransactionHashes;
-						try {
-							historicTransactionHashes = btc.electrumX.getAddressTransactions(script, false);
-						} catch (BitcoinException e) {
-							throw new UTXOProviderException(String.format("Unable to fetch transaction history for %s", address));
-						}
-
-						if (!historicTransactionHashes.isEmpty()) {
-							// Fully spent key - case (a)
-							btc.spentKeys.add(key);
-							wallet.getActiveKeyChain().markKeyAsUsed((DeterministicKey) key);
-							areAllKeysUnspent = false;
-						} else {
-							// Key never been used - case (b)
-							areAllKeysSpent = false;
-						}
-
-						continue;
-					}
-
-					// If we reach here, then there's definitely at least one unspent key
-					btc.spentKeys.remove(key);
-					areAllKeysSpent = false;
-
-					for (UnspentOutput unspentOutput : unspentOutputs) {
-						List<TransactionOutput> transactionOutputs;
-						try {
-							transactionOutputs = btc.getOutputs(unspentOutput.hash);
-						} catch (BitcoinException e) {
-							throw new UTXOProviderException(String.format("Unable to fetch outputs for TX %s",
-									HashCode.fromBytes(unspentOutput.hash)));
-						}
-
-						TransactionOutput transactionOutput = transactionOutputs.get(unspentOutput.index);
-
-						UTXO utxo = new UTXO(Sha256Hash.wrap(unspentOutput.hash), unspentOutput.index,
-								Coin.valueOf(unspentOutput.value), unspentOutput.height, coinbase,
-								transactionOutput.getScriptPubKey());
-
-						allUnspentOutputs.add(utxo);
-					}
-				}
-
-				if ((this.keySearchMode == KeySearchMode.REQUEST_MORE_IF_ALL_SPENT && areAllKeysSpent)
-						|| (this.keySearchMode == KeySearchMode.REQUEST_MORE_IF_ANY_SPENT && !areAllKeysUnspent)) {
-					// Generate some more keys
-					this.keyChain.setLookaheadSize(this.keyChain.getLookaheadSize() + LOOKAHEAD_INCREMENT);
-					this.keyChain.maybeLookAhead();
-
-					// This returns all keys, including those already in 'keys'
-					List<DeterministicKey> allLeafKeys = this.keyChain.getLeafKeys();
-					// Add only new keys onto our list of keys to search
-					List<DeterministicKey> newKeys = allLeafKeys.subList(ki, allLeafKeys.size());
-					keys.addAll(newKeys);
-					// Fall-through to checking more keys as now 'ki' is smaller than 'keys.size()' again
-				}
-
-				// If we have processed all keys, then we're done
-			} while (ki < keys.size());
-
-			return allUnspentOutputs;
-		}
-
-		public int getChainHeadHeight() throws UTXOProviderException {
-			try {
-				return btc.electrumX.getCurrentHeight();
-			} catch (BitcoinException e) {
-				throw new UTXOProviderException("Unable to determine Bitcoin chain height");
-			}
-		}
-
-		public NetworkParameters getParams() {
-			return btc.params;
-		}
-	}
-
-	// Utility methods for us
-
-	private byte[] addressToScript(String base58Address) {
-		Context.propagate(bitcoinjContext);
-		Address address = Address.fromString(this.params, base58Address);
-		return ScriptBuilder.createOutputScript(address).getProgram();
-	}
-
-}

src/main/java/org/qortal/crosschain/Bitcoin.java

@@ -0,0 +1,195 @@
+package org.qortal.crosschain;
+
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.EnumMap;
+import java.util.Map;
+
+import org.bitcoinj.core.Context;
+import org.bitcoinj.core.NetworkParameters;
+import org.bitcoinj.params.MainNetParams;
+import org.bitcoinj.params.RegTestParams;
+import org.bitcoinj.params.TestNet3Params;
+import org.qortal.crosschain.ElectrumX.Server;
+import org.qortal.crosschain.ElectrumX.Server.ConnectionType;
+import org.qortal.settings.Settings;
+
+public class Bitcoin extends Bitcoiny {
+
+	public static final String CURRENCY_CODE = "BTC";
+
+	// Temporary values until a dynamic fee system is written.
+	private static final long OLD_FEE_AMOUNT = 4_000L; // Not 5000 so that existing P2SH-B can output 1000, avoiding dust issue, leaving 4000 for fees.
+	private static final long NEW_FEE_TIMESTAMP = 1598280000000L; // milliseconds since epoch
+	private static final long NEW_FEE_AMOUNT = 10_000L;
+
+	private static final long NON_MAINNET_FEE = 1000L; // enough for TESTNET3 and should be OK for REGTEST
+
+	private static final Map<ElectrumX.Server.ConnectionType, Integer> DEFAULT_ELECTRUMX_PORTS = new EnumMap<>(ElectrumX.Server.ConnectionType.class);
+	static {
+		DEFAULT_ELECTRUMX_PORTS.put(ConnectionType.TCP, 50001);
+		DEFAULT_ELECTRUMX_PORTS.put(ConnectionType.SSL, 50002);
+	}
+
+	public enum BitcoinNet {
+		MAIN {
+			@Override
+			public NetworkParameters getParams() {
+				return MainNetParams.get();
+			}
+
+			@Override
+			public Collection<ElectrumX.Server> getServers() {
+				return Arrays.asList(
+						// Servers chosen on NO BASIS WHATSOEVER from various sources!
+						new Server("enode.duckdns.org", Server.ConnectionType.SSL, 50002),
+						new Server("electrumx.ml", Server.ConnectionType.SSL, 50002),
+						new Server("electrum.bitkoins.nl", Server.ConnectionType.SSL, 50512),
+						new Server("btc.electroncash.dk", Server.ConnectionType.SSL, 60002),
+						new Server("electrumx.electricnewyear.net", Server.ConnectionType.SSL, 50002),
+						new Server("dxm.no-ip.biz", Server.ConnectionType.TCP, 50001),
+						new Server("kirsche.emzy.de", Server.ConnectionType.TCP, 50001),
+						new Server("2AZZARITA.hopto.org", Server.ConnectionType.TCP, 50001),
+						new Server("xtrum.com", Server.ConnectionType.TCP, 50001),
+						new Server("electrum.srvmin.network", Server.ConnectionType.TCP, 50001),
+						new Server("electrumx.alexridevski.net", Server.ConnectionType.TCP, 50001),
+						new Server("bitcoin.lukechilds.co", Server.ConnectionType.TCP, 50001),
+						new Server("electrum.poiuty.com", Server.ConnectionType.TCP, 50001),
+						new Server("horsey.cryptocowboys.net", Server.ConnectionType.TCP, 50001),
+						new Server("electrum.emzy.de", Server.ConnectionType.TCP, 50001),
+						new Server("electrum-server.ninja", Server.ConnectionType.TCP, 50081),
+						new Server("bitcoin.electrumx.multicoin.co", Server.ConnectionType.TCP, 50001),
+						new Server("esx.geekhosters.com", Server.ConnectionType.TCP, 50001),
+						new Server("bitcoin.grey.pw", Server.ConnectionType.TCP, 50003),
+						new Server("exs.ignorelist.com", Server.ConnectionType.TCP, 50001),
+						new Server("electrum.coinext.com.br", Server.ConnectionType.TCP, 50001),
+						new Server("bitcoin.aranguren.org", Server.ConnectionType.TCP, 50001),
+						new Server("skbxmit.coinjoined.com", Server.ConnectionType.TCP, 50001),
+						new Server("alviss.coinjoined.com", Server.ConnectionType.TCP, 50001),
+						new Server("electrum2.privateservers.network", Server.ConnectionType.TCP, 50001),
+						new Server("electrumx.schulzemic.net", Server.ConnectionType.TCP, 50001),
+						new Server("bitcoins.sk", Server.ConnectionType.TCP, 56001),
+						new Server("node.mendonca.xyz", Server.ConnectionType.TCP, 50001),
+						new Server("bitcoin.aranguren.org", Server.ConnectionType.TCP, 50001));
+			}
+
+			@Override
+			public String getGenesisHash() {
+				return "000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f";
+			}
+
+			@Override
+			public long getP2shFee(Long timestamp) {
+				// TODO: This will need to be replaced with something better in the near future!
+				if (timestamp != null && timestamp < NEW_FEE_TIMESTAMP)
+					return OLD_FEE_AMOUNT;
+
+				return NEW_FEE_AMOUNT;
+			}
+		},
+		TEST3 {
+			@Override
+			public NetworkParameters getParams() {
+				return TestNet3Params.get();
+			}
+
+			@Override
+			public Collection<ElectrumX.Server> getServers() {
+				return Arrays.asList(
+						new Server("electrum.blockstream.info", Server.ConnectionType.TCP, 60001),
+						new Server("electrum.blockstream.info", Server.ConnectionType.SSL, 60002),
+						new Server("electrumx-test.1209k.com", Server.ConnectionType.SSL, 50002),
+						new Server("testnet.qtornado.com", Server.ConnectionType.TCP, 51001),
+						new Server("testnet.qtornado.com", Server.ConnectionType.SSL, 51002),
+						new Server("testnet.aranguren.org", Server.ConnectionType.TCP, 51001),
+						new Server("testnet.aranguren.org", Server.ConnectionType.SSL, 51002),
+						new Server("testnet.hsmiths.com", Server.ConnectionType.SSL, 53012));
+			}
+
+			@Override
+			public String getGenesisHash() {
+				return "000000000933ea01ad0ee984209779baaec3ced90fa3f408719526f8d77f4943";
+			}
+
+			@Override
+			public long getP2shFee(Long timestamp) {
+				return NON_MAINNET_FEE;
+			}
+		},
+		REGTEST {
+			@Override
+			public NetworkParameters getParams() {
+				return RegTestParams.get();
+			}
+
+			@Override
+			public Collection<ElectrumX.Server> getServers() {
+				return Arrays.asList(
+						new Server("localhost", Server.ConnectionType.TCP, 50001),
+						new Server("localhost", Server.ConnectionType.SSL, 50002));
+			}
+
+			@Override
+			public String getGenesisHash() {
+				// This is unique to each regtest instance
+				return null;
+			}
+
+			@Override
+			public long getP2shFee(Long timestamp) {
+				return NON_MAINNET_FEE;
+			}
+		};
+
+		public abstract NetworkParameters getParams();
+		public abstract Collection<ElectrumX.Server> getServers();
+		public abstract String getGenesisHash();
+		public abstract long getP2shFee(Long timestamp) throws ForeignBlockchainException;
+	}
+
+	private static Bitcoin instance;
+
+	private final BitcoinNet bitcoinNet;
+
+	// Constructors and instance
+
+	private Bitcoin(BitcoinNet bitcoinNet, BitcoinyBlockchainProvider blockchain, Context bitcoinjContext, String currencyCode) {
+		super(blockchain, bitcoinjContext, currencyCode);
+		this.bitcoinNet = bitcoinNet;
+
+		LOGGER.info(() -> String.format("Starting Bitcoin support using %s", this.bitcoinNet.name()));
+	}
+
+	public static synchronized Bitcoin getInstance() {
+		if (instance == null) {
+			BitcoinNet bitcoinNet = Settings.getInstance().getBitcoinNet();
+
+			BitcoinyBlockchainProvider electrumX = new ElectrumX("Bitcoin-" + bitcoinNet.name(), bitcoinNet.getGenesisHash(), bitcoinNet.getServers(), DEFAULT_ELECTRUMX_PORTS);
+			Context bitcoinjContext = new Context(bitcoinNet.getParams());
+
+			instance = new Bitcoin(bitcoinNet, electrumX, bitcoinjContext, CURRENCY_CODE);
+		}
+
+		return instance;
+	}
+
+	// Getters & setters
+
+	public static synchronized void resetForTesting() {
+		instance = null;
+	}
+
+	// Actual useful methods for use by other classes
+
+	/**
+	 * Returns estimated BTC fee, in sats per 1000bytes, optionally for historic timestamp.
+	 * 
+	 * @param timestamp optional milliseconds since epoch, or null for 'now'
+	 * @return sats per 1000bytes, or throws ForeignBlockchainException if something went wrong
+	 */
+	@Override
+	public long getP2shFee(Long timestamp) throws ForeignBlockchainException {
+		return this.bitcoinNet.getP2shFee(timestamp);
+	}
+
+}

src/main/java/org/qortal/crosschain/BitcoinACCTv1.java

@@ -1,13 +1,10 @@
 package org.qortal.crosschain;
 
-import static java.util.Arrays.stream;
-import static java.util.stream.Collectors.toMap;
 import static org.ciyam.at.OpCode.calcOffset;
 
 import java.nio.ByteBuffer;
 import java.util.Arrays;
 import java.util.List;
-import java.util.Map;
 
 import org.ciyam.at.API;
 import org.ciyam.at.CompilationException;
@@ -101,11 +98,12 @@ import com.google.common.primitives.Bytes;
  * </li>
  * </ul>
  */
-public class BTCACCT {
+public class BitcoinACCTv1 implements ACCT {
+
+	public static final String NAME = BitcoinACCTv1.class.getSimpleName();
+	public static final byte[] CODE_BYTES_HASH = HashCode.fromString("f7f419522a9aaa3c671149878f8c1374dfc59d4fd86ca43ff2a4d913cfbc9e89").asBytes(); // SHA256 of AT code bytes
 
 	public static final int SECRET_LENGTH = 32;
-	public static final int MIN_LOCKTIME = 1500000000;
-	public static final byte[] CODE_BYTES_HASH = HashCode.fromString("f7f419522a9aaa3c671149878f8c1374dfc59d4fd86ca43ff2a4d913cfbc9e89").asBytes(); // SHA256 of AT code bytes
 
 	/** <b>Value</b> offset into AT segment where 'mode' variable (long) is stored. (Multiply by MachineState.VALUE_SIZE for byte offset). */
 	private static final int MODE_VALUE_OFFSET = 68;
@@ -126,22 +124,31 @@ public class BTCACCT {
 	public static final int REDEEM_MESSAGE_LENGTH = 32 /*secret*/ + 32 /*secret*/ + 32 /*partner's Qortal receiving address padded from 25 to 32*/;
 	public static final int CANCEL_MESSAGE_LENGTH = 32 /*AT creator's Qortal address*/;
 
-	public enum Mode {
-		OFFERING(0), TRADING(1), CANCELLED(2), REFUNDED(3), REDEEMED(4);
+	private static BitcoinACCTv1 instance;
 
-		public final int value;
-		private static final Map<Integer, Mode> map = stream(Mode.values()).collect(toMap(mode -> mode.value, mode -> mode));
-
-		Mode(int value) {
-			this.value = value;
-		}
-
-		public static Mode valueOf(int value) {
-			return map.get(value);
-		}
+	private BitcoinACCTv1() {
 	}
 
-	private BTCACCT() {
+	public static synchronized BitcoinACCTv1 getInstance() {
+		if (instance == null)
+			instance = new BitcoinACCTv1();
+
+		return instance;
+	}
+
+	@Override
+	public byte[] getCodeBytesHash() {
+		return CODE_BYTES_HASH;
+	}
+
+	@Override
+	public int getModeByteOffset() {
+		return MODE_BYTE_OFFSET;
+	}
+
+	@Override
+	public ForeignBlockchain getBlockchain() {
+		return Bitcoin.getInstance();
 	}
 
 	/**
@@ -156,7 +163,6 @@ public class BTCACCT {
 	 * @param qortAmount how much QORT to pay trade partner if they send correct 32-byte secrets to AT
 	 * @param bitcoinAmount how much BTC the AT creator is expecting to trade
 	 * @param tradeTimeout suggested timeout for entire trade
-	 * @return
 	 */
 	public static byte[] buildQortalAT(String creatorTradeAddress, byte[] bitcoinPublicKeyHash, byte[] hashOfSecretB, long qortAmount, long bitcoinAmount, int tradeTimeout) {
 		// Labels for data segment addresses
@@ -419,7 +425,7 @@ public class BTCACCT {
 				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender3, addrCreatorAddress3, calcOffset(codeByteBuffer, labelNotTradeNorCancelTxn)));
 				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender4, addrCreatorAddress4, calcOffset(codeByteBuffer, labelNotTradeNorCancelTxn)));
 				// Partner address is AT creator's address, so cancel offer and finish.
-				codeByteBuffer.put(OpCode.SET_VAL.compile(addrMode, Mode.CANCELLED.value));
+				codeByteBuffer.put(OpCode.SET_VAL.compile(addrMode, AcctMode.CANCELLED.value));
 				// We're finished forever (finishing auto-refunds remaining balance to AT creator)
 				codeByteBuffer.put(OpCode.FIN_IMD.compile());
 
@@ -470,7 +476,7 @@ public class BTCACCT {
 				codeByteBuffer.put(OpCode.EXT_FUN_RET_DAT_2.compile(FunctionCode.ADD_MINUTES_TO_TIMESTAMP, addrRefundTimestamp, addrLastTxnTimestamp, addrRefundTimeout));
 
 				/* We are in 'trade mode' */
-				codeByteBuffer.put(OpCode.SET_VAL.compile(addrMode, Mode.TRADING.value));
+				codeByteBuffer.put(OpCode.SET_VAL.compile(addrMode, AcctMode.TRADING.value));
 
 				// Set restart position to after this opcode
 				codeByteBuffer.put(OpCode.SET_PCS.compile());
@@ -568,7 +574,7 @@ public class BTCACCT {
 				// Pay AT's balance to receiving address
 				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(FunctionCode.PAY_TO_ADDRESS_IN_B, addrQortAmount));
 				// Set redeemed mode
-				codeByteBuffer.put(OpCode.SET_VAL.compile(addrMode, Mode.REDEEMED.value));
+				codeByteBuffer.put(OpCode.SET_VAL.compile(addrMode, AcctMode.REDEEMED.value));
 				// We're finished forever (finishing auto-refunds remaining balance to AT creator)
 				codeByteBuffer.put(OpCode.FIN_IMD.compile());
 
@@ -578,7 +584,7 @@ public class BTCACCT {
 				labelRefund = codeByteBuffer.position();
 
 				// Set refunded mode
-				codeByteBuffer.put(OpCode.SET_VAL.compile(addrMode, Mode.REFUNDED.value));
+				codeByteBuffer.put(OpCode.SET_VAL.compile(addrMode, AcctMode.REFUNDED.value));
 				// We're finished forever (finishing auto-refunds remaining balance to AT creator)
 				codeByteBuffer.put(OpCode.FIN_IMD.compile());
 			} catch (CompilationException e) {
@@ -591,7 +597,7 @@ public class BTCACCT {
 		byte[] codeBytes = new byte[codeByteBuffer.limit()];
 		codeByteBuffer.get(codeBytes);
 
-		assert Arrays.equals(Crypto.digest(codeBytes), BTCACCT.CODE_BYTES_HASH)
+		assert Arrays.equals(Crypto.digest(codeBytes), BitcoinACCTv1.CODE_BYTES_HASH)
 			: String.format("BTCACCT.CODE_BYTES_HASH mismatch: expected %s, actual %s", HashCode.fromBytes(CODE_BYTES_HASH), HashCode.fromBytes(Crypto.digest(codeBytes)));
 
 		final short ciyamAtVersion = 2;
@@ -604,41 +610,34 @@ public class BTCACCT {
 
 	/**
 	 * Returns CrossChainTradeData with useful info extracted from AT.
-	 * 
-	 * @param repository
-	 * @param atAddress
-	 * @throws DataException
 	 */
-	public static CrossChainTradeData populateTradeData(Repository repository, ATData atData) throws DataException {
+	@Override
+	public CrossChainTradeData populateTradeData(Repository repository, ATData atData) throws DataException {
 		ATStateData atStateData = repository.getATRepository().getLatestATState(atData.getATAddress());
 		return populateTradeData(repository, atData.getCreatorPublicKey(), atData.getCreation(), atStateData);
 	}
 
 	/**
 	 * Returns CrossChainTradeData with useful info extracted from AT.
-	 * 
-	 * @param repository
-	 * @param atAddress
-	 * @throws DataException
 	 */
-	public static CrossChainTradeData populateTradeData(Repository repository, ATStateData atStateData) throws DataException {
+	@Override
+	public CrossChainTradeData populateTradeData(Repository repository, ATStateData atStateData) throws DataException {
 		ATData atData = repository.getATRepository().fromATAddress(atStateData.getATAddress());
 		return populateTradeData(repository, atData.getCreatorPublicKey(), atData.getCreation(), atStateData);
 	}
 
 	/**
 	 * Returns CrossChainTradeData with useful info extracted from AT.
-	 * 
-	 * @param repository
-	 * @param atAddress
-	 * @throws DataException
 	 */
-	public static CrossChainTradeData populateTradeData(Repository repository, byte[] creatorPublicKey, long creationTimestamp, ATStateData atStateData) throws DataException {
+	public CrossChainTradeData populateTradeData(Repository repository, byte[] creatorPublicKey, long creationTimestamp, ATStateData atStateData) throws DataException {
 		byte[] addressBytes = new byte[25]; // for general use
 		String atAddress = atStateData.getATAddress();
 
 		CrossChainTradeData tradeData = new CrossChainTradeData();
 
+		tradeData.foreignBlockchain = SupportedBlockchain.BITCOIN.name();
+		tradeData.acctName = NAME;
+
 		tradeData.qortalAtAddress = atAddress;
 		tradeData.qortalCreator = Crypto.toAddress(creatorPublicKey);
 		tradeData.creationTimestamp = creationTimestamp;
@@ -658,9 +657,9 @@ public class BTCACCT {
 		dataByteBuffer.position(dataByteBuffer.position() + 32 - addressBytes.length);
 
 		// Creator's Bitcoin/foreign public key hash
-		tradeData.creatorBitcoinPKH = new byte[20];
-		dataByteBuffer.get(tradeData.creatorBitcoinPKH);
-		dataByteBuffer.position(dataByteBuffer.position() + 32 - tradeData.creatorBitcoinPKH.length); // skip to 32 bytes
+		tradeData.creatorForeignPKH = new byte[20];
+		dataByteBuffer.get(tradeData.creatorForeignPKH);
+		dataByteBuffer.position(dataByteBuffer.position() + 32 - tradeData.creatorForeignPKH.length); // skip to 32 bytes
 
 		// Hash of secret B
 		tradeData.hashOfSecretB = new byte[20];
@@ -671,7 +670,7 @@ public class BTCACCT {
 		tradeData.qortAmount = dataByteBuffer.getLong();
 
 		// Expected BTC amount
-		tradeData.expectedBitcoin = dataByteBuffer.getLong();
+		tradeData.expectedForeignAmount = dataByteBuffer.getLong();
 
 		// Trade timeout
 		tradeData.tradeTimeout = (int) dataByteBuffer.getLong();
@@ -784,26 +783,28 @@ public class BTCACCT {
 
 		// Trade AT's 'mode'
 		long modeValue = dataByteBuffer.getLong();
-		Mode mode = Mode.valueOf((int) (modeValue & 0xffL));
+		AcctMode acctMode = AcctMode.valueOf((int) (modeValue & 0xffL));
 
 		/* End of variables */
 
-		if (mode != null && mode != Mode.OFFERING) {
-			tradeData.mode = mode;
+		if (acctMode != null && acctMode != AcctMode.OFFERING) {
+			tradeData.mode = acctMode;
 			tradeData.refundTimeout = refundTimeout;
 			tradeData.tradeRefundHeight = new Timestamp(tradeRefundTimestamp).blockHeight;
 			tradeData.qortalPartnerAddress = qortalRecipient;
 			tradeData.hashOfSecretA = hashOfSecretA;
-			tradeData.partnerBitcoinPKH = partnerBitcoinPKH;
+			tradeData.partnerForeignPKH = partnerBitcoinPKH;
 			tradeData.lockTimeA = lockTimeA;
 			tradeData.lockTimeB = lockTimeB;
 
-			if (mode == Mode.REDEEMED)
+			if (acctMode == AcctMode.REDEEMED)
 				tradeData.qortalPartnerReceivingAddress = Base58.encode(partnerReceivingAddress);
 		} else {
-			tradeData.mode = Mode.OFFERING;
+			tradeData.mode = AcctMode.OFFERING;
 		}
 
+		tradeData.duplicateDeprecated();
+
 		return tradeData;
 	}
 
@@ -843,7 +844,8 @@ public class BTCACCT {
 	}
 
 	/** Returns 'cancel' MESSAGE payload for AT creator to cancel trade AT. */
-	public static byte[] buildCancelMessage(String creatorQortalAddress) {
+	@Override
+	public byte[] buildCancelMessage(String creatorQortalAddress) {
 		byte[] data = new byte[CANCEL_MESSAGE_LENGTH];
 		byte[] creatorQortalAddressBytes = Base58.decode(creatorQortalAddress);
 
@@ -866,7 +868,7 @@ public class BTCACCT {
 
 	/** Returns P2SH-B lockTime (epoch seconds) based on trade partner's 'offer' MESSAGE timestamp and P2SH-A locktime. */
 	public static int calcLockTimeB(long offerMessageTimestamp, int lockTimeA) {
-		// lockTimeB is halfway between offerMessageTimesamp and lockTimeA
+		// lockTimeB is halfway between offerMessageTimestamp and lockTimeA
 		return (int) ((lockTimeA + (offerMessageTimestamp / 1000L)) / 2L);
 	}
 

src/main/java/org/qortal/crosschain/BitcoinException.java

@@ -1,57 +0,0 @@
-package org.qortal.crosschain;
-
-@SuppressWarnings("serial")
-public class BitcoinException extends Exception {
-
-	public BitcoinException() {
-		super();
-	}
-
-	public BitcoinException(String message) {
-		super(message);
-	}
-
-	public static class NetworkException extends BitcoinException {
-		private final Integer daemonErrorCode;
-
-		public NetworkException() {
-			super();
-			this.daemonErrorCode = null;
-		}
-
-		public NetworkException(String message) {
-			super(message);
-			this.daemonErrorCode = null;
-		}
-
-		public NetworkException(int errorCode, String message) {
-			super(message);
-			this.daemonErrorCode = errorCode;
-		}
-
-		public Integer getDaemonErrorCode() {
-			return this.daemonErrorCode;
-		}
-	}
-
-	public static class NotFoundException extends BitcoinException {
-		public NotFoundException() {
-			super();
-		}
-
-		public NotFoundException(String message) {
-			super(message);
-		}
-	}
-
-	public static class InsufficientFundsException extends BitcoinException {
-		public InsufficientFundsException() {
-			super();
-		}
-
-		public InsufficientFundsException(String message) {
-			super(message);
-		}
-	}
-
-}

src/main/java/org/qortal/crosschain/BitcoinNetworkProvider.java

@@ -1,31 +0,0 @@
-package org.qortal.crosschain;
-
-import java.util.List;
-
-interface BitcoinNetworkProvider {
-
-	/** Returns current blockchain height. */
-	int getCurrentHeight() throws BitcoinException;
-
-	/** Returns a list of raw block headers, starting at <tt>startHeight</tt> (inclusive), up to <tt>count</tt> max. */
-	List<byte[]> getRawBlockHeaders(int startHeight, int count) throws BitcoinException;
-
-	/** Returns balance of address represented by <tt>scriptPubKey</tt>. */
-	long getConfirmedBalance(byte[] scriptPubKey) throws BitcoinException;
-
-	/** Returns raw, serialized, transaction bytes given <tt>txHash</tt>. */
-	byte[] getRawTransaction(String txHash) throws BitcoinException;
-
-	/** Returns unpacked transaction given <tt>txHash</tt>. */
-	BitcoinTransaction getTransaction(String txHash) throws BitcoinException;
-
-	/** Returns list of transaction hashes (and heights) for address represented by <tt>scriptPubKey</tt>, optionally including unconfirmed transactions. */
-	List<TransactionHash> getAddressTransactions(byte[] scriptPubKey, boolean includeUnconfirmed) throws BitcoinException;
-
-	/** Returns list of unspent transaction outputs for address represented by <tt>scriptPubKey</tt>, optionally including unconfirmed transactions. */
-	List<UnspentOutput> getUnspentOutputs(byte[] scriptPubKey, boolean includeUnconfirmed) throws BitcoinException;
-
-	/** Broadcasts raw, serialized, transaction bytes to network, returning success/failure. */
-	boolean broadcastTransaction(byte[] rawTransaction) throws BitcoinException;
-
-}

src/main/java/org/qortal/crosschain/Bitcoiny.java

@@ -0,0 +1,704 @@
+package org.qortal.crosschain;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.bitcoinj.core.Address;
+import org.bitcoinj.core.AddressFormatException;
+import org.bitcoinj.core.Coin;
+import org.bitcoinj.core.Context;
+import org.bitcoinj.core.ECKey;
+import org.bitcoinj.core.InsufficientMoneyException;
+import org.bitcoinj.core.LegacyAddress;
+import org.bitcoinj.core.NetworkParameters;
+import org.bitcoinj.core.Sha256Hash;
+import org.bitcoinj.core.Transaction;
+import org.bitcoinj.core.TransactionOutput;
+import org.bitcoinj.core.UTXO;
+import org.bitcoinj.core.UTXOProvider;
+import org.bitcoinj.core.UTXOProviderException;
+import org.bitcoinj.crypto.ChildNumber;
+import org.bitcoinj.crypto.DeterministicHierarchy;
+import org.bitcoinj.crypto.DeterministicKey;
+import org.bitcoinj.script.Script.ScriptType;
+import org.bitcoinj.script.ScriptBuilder;
+import org.bitcoinj.wallet.DeterministicKeyChain;
+import org.bitcoinj.wallet.SendRequest;
+import org.bitcoinj.wallet.Wallet;
+import org.qortal.api.model.SimpleForeignTransaction;
+import org.qortal.crypto.Crypto;
+import org.qortal.utils.Amounts;
+import org.qortal.utils.BitTwiddling;
+
+import com.google.common.hash.HashCode;
+
+/** Bitcoin-like (Bitcoin, Litecoin, etc.) support */
+public abstract class Bitcoiny implements ForeignBlockchain {
+
+	protected static final Logger LOGGER = LogManager.getLogger(Bitcoiny.class);
+
+	public static final int HASH160_LENGTH = 20;
+
+	protected final BitcoinyBlockchainProvider blockchain;
+	protected final Context bitcoinjContext;
+	protected final String currencyCode;
+
+	protected final NetworkParameters params;
+
+	/** Keys that have been previously marked as fully spent,<br>
+	 * i.e. keys with transactions but with no unspent outputs. */
+	protected final Set<ECKey> spentKeys = Collections.synchronizedSet(new HashSet<>());
+
+	/** How many bitcoinj wallet keys to generate in each batch. */
+	private static final int WALLET_KEY_LOOKAHEAD_INCREMENT = 3;
+
+	/** Byte offset into raw block headers to block timestamp. */
+	private static final int TIMESTAMP_OFFSET = 4 + 32 + 32;
+
+	// Constructors and instance
+
+	protected Bitcoiny(BitcoinyBlockchainProvider blockchain, Context bitcoinjContext, String currencyCode) {
+		this.blockchain = blockchain;
+		this.bitcoinjContext = bitcoinjContext;
+		this.currencyCode = currencyCode;
+
+		this.params = this.bitcoinjContext.getParams();
+	}
+
+	// Getters & setters
+
+	public BitcoinyBlockchainProvider getBlockchainProvider() {
+		return this.blockchain;
+	}
+
+	public Context getBitcoinjContext() {
+		return this.bitcoinjContext;
+	}
+
+	public String getCurrencyCode() {
+		return this.currencyCode;
+	}
+
+	public NetworkParameters getNetworkParameters() {
+		return this.params;
+	}
+
+	// Interface obligations 
+
+	@Override
+	public boolean isValidAddress(String address) {
+		try {
+			ScriptType addressType = Address.fromString(this.params, address).getOutputScriptType();
+
+			return addressType == ScriptType.P2PKH || addressType == ScriptType.P2SH;
+		} catch (AddressFormatException e) {
+			return false;
+		}
+	}
+
+	@Override
+	public boolean isValidWalletKey(String walletKey) {
+		return this.isValidDeterministicKey(walletKey);
+	}
+
+	// Actual useful methods for use by other classes
+
+	public String format(Coin amount) {
+		return this.format(amount.value);
+	}
+
+	public String format(long amount) {
+		return Amounts.prettyAmount(amount) + " " + this.currencyCode;
+	}
+
+	public boolean isValidDeterministicKey(String key58) {
+		try {
+			Context.propagate(this.bitcoinjContext);
+			DeterministicKey.deserializeB58(null, key58, this.params);
+			return true;
+		} catch (IllegalArgumentException e) {
+			return false;
+		}
+	}
+
+	/** Returns P2PKH address using passed public key hash. */
+	public String pkhToAddress(byte[] publicKeyHash) {
+		Context.propagate(this.bitcoinjContext);
+		return LegacyAddress.fromPubKeyHash(this.params, publicKeyHash).toString();
+	}
+
+	/** Returns P2SH address using passed redeem script. */
+	public String deriveP2shAddress(byte[] redeemScriptBytes) {
+		Context.propagate(bitcoinjContext);
+		byte[] redeemScriptHash = Crypto.hash160(redeemScriptBytes);
+		return LegacyAddress.fromScriptHash(this.params, redeemScriptHash).toString();
+	}
+
+	/**
+	 * Returns median timestamp from latest 11 blocks, in seconds.
+	 * <p>
+	 * @throws ForeignBlockchainException if error occurs
+	 */
+	public int getMedianBlockTime() throws ForeignBlockchainException {
+		int height = this.blockchain.getCurrentHeight();
+
+		// Grab latest 11 blocks
+		List<byte[]> blockHeaders = this.blockchain.getRawBlockHeaders(height - 11, 11);
+		if (blockHeaders.size() < 11)
+			throw new ForeignBlockchainException("Not enough blocks to determine median block time");
+
+		List<Integer> blockTimestamps = blockHeaders.stream().map(blockHeader -> BitTwiddling.intFromLEBytes(blockHeader, TIMESTAMP_OFFSET)).collect(Collectors.toList());
+
+		// Descending order
+		blockTimestamps.sort((a, b) -> Integer.compare(b, a));
+
+		// Pick median
+		return blockTimestamps.get(5);
+	}
+
+	/** Returns fee per transaction KB. To be overridden for testnet/regtest. */
+	public Coin getFeePerKb() {
+		return this.bitcoinjContext.getFeePerKb();
+	}
+
+	/**
+	 * Returns fixed P2SH spending fee, in sats per 1000bytes, optionally for historic timestamp.
+	 * 
+	 * @param timestamp optional milliseconds since epoch, or null for 'now'
+	 * @return sats per 1000bytes
+	 * @throws ForeignBlockchainException if something went wrong
+	 */
+	public abstract long getP2shFee(Long timestamp) throws ForeignBlockchainException;
+
+	/**
+	 * Returns confirmed balance, based on passed payment script.
+	 * <p>
+	 * @return confirmed balance, or zero if script unknown
+	 * @throws ForeignBlockchainException if there was an error
+	 */
+	public long getConfirmedBalance(String base58Address) throws ForeignBlockchainException {
+		return this.blockchain.getConfirmedBalance(addressToScriptPubKey(base58Address));
+	}
+
+	/**
+	 * Returns list of unspent outputs pertaining to passed address.
+	 * <p>
+	 * @return list of unspent outputs, or empty list if address unknown
+	 * @throws ForeignBlockchainException if there was an error.
+	 */
+	// TODO: don't return bitcoinj-based objects like TransactionOutput, use BitcoinyTransaction.Output instead
+	public List<TransactionOutput> getUnspentOutputs(String base58Address) throws ForeignBlockchainException {
+		List<UnspentOutput> unspentOutputs = this.blockchain.getUnspentOutputs(addressToScriptPubKey(base58Address), false);
+
+		List<TransactionOutput> unspentTransactionOutputs = new ArrayList<>();
+		for (UnspentOutput unspentOutput : unspentOutputs) {
+			List<TransactionOutput> transactionOutputs = this.getOutputs(unspentOutput.hash);
+
+			unspentTransactionOutputs.add(transactionOutputs.get(unspentOutput.index));
+		}
+
+		return unspentTransactionOutputs;
+	}
+
+	/**
+	 * Returns list of outputs pertaining to passed transaction hash.
+	 * <p>
+	 * @return list of outputs, or empty list if transaction unknown
+	 * @throws ForeignBlockchainException if there was an error.
+	 */
+	// TODO: don't return bitcoinj-based objects like TransactionOutput, use BitcoinyTransaction.Output instead
+	public List<TransactionOutput> getOutputs(byte[] txHash) throws ForeignBlockchainException {
+		byte[] rawTransactionBytes = this.blockchain.getRawTransaction(txHash);
+
+		Context.propagate(bitcoinjContext);
+		Transaction transaction = new Transaction(this.params, rawTransactionBytes);
+		return transaction.getOutputs();
+	}
+
+	/**
+	 * Returns list of transaction hashes pertaining to passed address.
+	 * <p>
+	 * @return list of unspent outputs, or empty list if script unknown
+	 * @throws ForeignBlockchainException if there was an error.
+	 */
+	public List<TransactionHash> getAddressTransactions(String base58Address, boolean includeUnconfirmed) throws ForeignBlockchainException {
+		return this.blockchain.getAddressTransactions(addressToScriptPubKey(base58Address), includeUnconfirmed);
+	}
+
+	/**
+	 * Returns list of raw, confirmed transactions involving given address.
+	 * <p>
+	 * @throws ForeignBlockchainException if there was an error
+	 */
+	public List<byte[]> getAddressTransactions(String base58Address) throws ForeignBlockchainException {
+		List<TransactionHash> transactionHashes = this.blockchain.getAddressTransactions(addressToScriptPubKey(base58Address), false);
+
+		List<byte[]> rawTransactions = new ArrayList<>();
+		for (TransactionHash transactionInfo : transactionHashes) {
+			byte[] rawTransaction = this.blockchain.getRawTransaction(HashCode.fromString(transactionInfo.txHash).asBytes());
+			rawTransactions.add(rawTransaction);
+		}
+
+		return rawTransactions;
+	}
+
+	/**
+	 * Returns transaction info for passed transaction hash.
+	 * <p>
+	 * @throws ForeignBlockchainException.NotFoundException if transaction unknown
+	 * @throws ForeignBlockchainException if error occurs
+	 */
+	public BitcoinyTransaction getTransaction(String txHash) throws ForeignBlockchainException {
+		return this.blockchain.getTransaction(txHash);
+	}
+
+	/**
+	 * Broadcasts raw transaction to network.
+	 * <p>
+	 * @throws ForeignBlockchainException if error occurs
+	 */
+	public void broadcastTransaction(Transaction transaction) throws ForeignBlockchainException {
+		this.blockchain.broadcastTransaction(transaction.bitcoinSerialize());
+	}
+
+	/**
+	 * Returns bitcoinj transaction sending <tt>amount</tt> to <tt>recipient</tt>.
+	 * 
+	 * @param xprv58 BIP32 private key
+	 * @param recipient P2PKH address
+	 * @param amount unscaled amount
+	 * @param feePerByte unscaled fee per byte, or null to use default fees
+	 * @return transaction, or null if insufficient funds
+	 */
+	public Transaction buildSpend(String xprv58, String recipient, long amount, Long feePerByte) {
+		Context.propagate(bitcoinjContext);
+
+		Wallet wallet = Wallet.fromSpendingKeyB58(this.params, xprv58, DeterministicHierarchy.BIP32_STANDARDISATION_TIME_SECS);
+		wallet.setUTXOProvider(new WalletAwareUTXOProvider(this, wallet));
+
+		Address destination = Address.fromString(this.params, recipient);
+		SendRequest sendRequest = SendRequest.to(destination, Coin.valueOf(amount));
+
+		if (feePerByte != null)
+			sendRequest.feePerKb = Coin.valueOf(feePerByte * 1000L); // Note: 1000 not 1024
+		else
+			// Allow override of default for TestNet3, etc.
+			sendRequest.feePerKb = this.getFeePerKb();
+
+		try {
+			wallet.completeTx(sendRequest);
+			return sendRequest.tx;
+		} catch (InsufficientMoneyException e) {
+			return null;
+		}
+	}
+
+	/**
+	 * Returns bitcoinj transaction sending <tt>amount</tt> to <tt>recipient</tt> using default fees.
+	 * 
+	 * @param xprv58 BIP32 private key
+	 * @param recipient P2PKH address
+	 * @param amount unscaled amount
+	 * @return transaction, or null if insufficient funds
+	 */
+	public Transaction buildSpend(String xprv58, String recipient, long amount) {
+		return buildSpend(xprv58, recipient, amount, null);
+	}
+
+	/**
+	 * Returns unspent Bitcoin balance given 'm' BIP32 key.
+	 *
+	 * @param key58 BIP32/HD extended Bitcoin private/public key
+	 * @return unspent BTC balance, or null if unable to determine balance
+	 */
+	public Long getWalletBalance(String key58) {
+		Context.propagate(bitcoinjContext);
+
+		Wallet wallet = walletFromDeterministicKey58(key58);
+		wallet.setUTXOProvider(new WalletAwareUTXOProvider(this, wallet));
+
+		Coin balance = wallet.getBalance();
+		if (balance == null)
+			return null;
+
+		return balance.value;
+	}
+
+	public List<BitcoinyTransaction> getWalletTransactions(String key58) throws ForeignBlockchainException {
+		Context.propagate(bitcoinjContext);
+
+		Wallet wallet = walletFromDeterministicKey58(key58);
+		DeterministicKeyChain keyChain = wallet.getActiveKeyChain();
+
+		keyChain.setLookaheadSize(Bitcoiny.WALLET_KEY_LOOKAHEAD_INCREMENT);
+		keyChain.maybeLookAhead();
+
+		List<DeterministicKey> keys = new ArrayList<>(keyChain.getLeafKeys());
+
+		Set<BitcoinyTransaction> walletTransactions = new HashSet<>();
+
+		int ki = 0;
+		do {
+			boolean areAllKeysUnused = true;
+
+			for (; ki < keys.size(); ++ki) {
+				DeterministicKey dKey = keys.get(ki);
+
+				// Check for transactions
+				Address address = Address.fromKey(this.params, dKey, ScriptType.P2PKH);
+				byte[] script = ScriptBuilder.createOutputScript(address).getProgram();
+
+				// Ask for transaction history - if it's empty then key has never been used
+				List<TransactionHash> historicTransactionHashes = this.blockchain.getAddressTransactions(script, false);
+
+				if (!historicTransactionHashes.isEmpty()) {
+					areAllKeysUnused = false;
+
+					for (TransactionHash transactionHash : historicTransactionHashes)
+						walletTransactions.add(this.getTransaction(transactionHash.txHash));
+				}
+			}
+
+			if (areAllKeysUnused)
+				// No transactions for this batch of keys so assume we're done searching.
+				break;
+
+			// Generate some more keys
+			keys.addAll(generateMoreKeys(keyChain));
+
+			// Process new keys
+		} while (true);
+
+		return walletTransactions.stream().collect(Collectors.toList());
+	}
+
+	/**
+	 * Returns first unused receive address given 'm' BIP32 key.
+	 *
+	 * @param key58 BIP32/HD extended Bitcoin private/public key
+	 * @return P2PKH address
+	 * @throws ForeignBlockchainException if something went wrong
+	 */
+	public String getUnusedReceiveAddress(String key58) throws ForeignBlockchainException {
+		Context.propagate(bitcoinjContext);
+
+		Wallet wallet = walletFromDeterministicKey58(key58);
+		DeterministicKeyChain keyChain = wallet.getActiveKeyChain();
+
+		keyChain.setLookaheadSize(Bitcoiny.WALLET_KEY_LOOKAHEAD_INCREMENT);
+		keyChain.maybeLookAhead();
+
+		final int keyChainPathSize = keyChain.getAccountPath().size();
+		List<DeterministicKey> keys = new ArrayList<>(keyChain.getLeafKeys());
+
+		int ki = 0;
+		do {
+			for (; ki < keys.size(); ++ki) {
+				DeterministicKey dKey = keys.get(ki);
+				List<ChildNumber> dKeyPath = dKey.getPath();
+
+				// If keyChain is based on 'm', then make sure dKey is m/0/ki - i.e. a 'receive' address, not 'change' (m/1/ki)
+				if (dKeyPath.size() != keyChainPathSize + 2 || dKeyPath.get(dKeyPath.size() - 2) != ChildNumber.ZERO)
+					continue;
+
+				// Check unspent
+				Address address = Address.fromKey(this.params, dKey, ScriptType.P2PKH);
+				byte[] script = ScriptBuilder.createOutputScript(address).getProgram();
+
+				List<UnspentOutput> unspentOutputs = this.blockchain.getUnspentOutputs(script, false);
+
+				/*
+				 * If there are no unspent outputs then either:
+				 * a) all the outputs have been spent
+				 * b) address has never been used
+				 * 
+				 * For case (a) we want to remember not to check this address (key) again.
+				 */
+
+				if (unspentOutputs.isEmpty()) {
+					// If this is a known key that has been spent before, then we can skip asking for transaction history
+					if (this.spentKeys.contains(dKey)) {
+						wallet.getActiveKeyChain().markKeyAsUsed(dKey);
+						continue;
+					}
+
+					// Ask for transaction history - if it's empty then key has never been used
+					List<TransactionHash> historicTransactionHashes = this.blockchain.getAddressTransactions(script, false);
+
+					if (!historicTransactionHashes.isEmpty()) {
+						// Fully spent key - case (a)
+						this.spentKeys.add(dKey);
+						wallet.getActiveKeyChain().markKeyAsUsed(dKey);
+						continue;
+					}
+
+					// Key never been used - case (b)
+					return address.toString();
+				}
+
+				// Key has unspent outputs, hence used, so no good to us
+				this.spentKeys.remove(dKey);
+			}
+
+			// Generate some more keys
+			keys.addAll(generateMoreKeys(keyChain));
+
+			// Process new keys
+		} while (true);
+	}
+
+	// UTXOProvider support
+
+	static class WalletAwareUTXOProvider implements UTXOProvider {
+		private final Bitcoiny bitcoiny;
+		private final Wallet wallet;
+
+		private final DeterministicKeyChain keyChain;
+
+		public WalletAwareUTXOProvider(Bitcoiny bitcoiny, Wallet wallet) {
+			this.bitcoiny = bitcoiny;
+			this.wallet = wallet;
+			this.keyChain = this.wallet.getActiveKeyChain();
+
+			// Set up wallet's key chain
+			this.keyChain.setLookaheadSize(Bitcoiny.WALLET_KEY_LOOKAHEAD_INCREMENT);
+			this.keyChain.maybeLookAhead();
+		}
+
+		@Override
+		public List<UTXO> getOpenTransactionOutputs(List<ECKey> keys) throws UTXOProviderException {
+			List<UTXO> allUnspentOutputs = new ArrayList<>();
+			final boolean coinbase = false;
+
+			int ki = 0;
+			do {
+				boolean areAllKeysUnspent = true;
+
+				for (; ki < keys.size(); ++ki) {
+					ECKey key = keys.get(ki);
+
+					Address address = Address.fromKey(this.bitcoiny.params, key, ScriptType.P2PKH);
+					byte[] script = ScriptBuilder.createOutputScript(address).getProgram();
+
+					List<UnspentOutput> unspentOutputs;
+					try {
+						unspentOutputs = this.bitcoiny.blockchain.getUnspentOutputs(script, false);
+					} catch (ForeignBlockchainException e) {
+						throw new UTXOProviderException(String.format("Unable to fetch unspent outputs for %s", address));
+					}
+
+					/*
+					 * If there are no unspent outputs then either:
+					 * a) all the outputs have been spent
+					 * b) address has never been used
+					 * 
+					 * For case (a) we want to remember not to check this address (key) again.
+					 */
+
+					if (unspentOutputs.isEmpty()) {
+						// If this is a known key that has been spent before, then we can skip asking for transaction history
+						if (this.bitcoiny.spentKeys.contains(key)) {
+							this.wallet.getActiveKeyChain().markKeyAsUsed((DeterministicKey) key);
+							areAllKeysUnspent = false;
+							continue;
+						}
+
+						// Ask for transaction history - if it's empty then key has never been used
+						List<TransactionHash> historicTransactionHashes;
+						try {
+							historicTransactionHashes = this.bitcoiny.blockchain.getAddressTransactions(script, false);
+						} catch (ForeignBlockchainException e) {
+							throw new UTXOProviderException(String.format("Unable to fetch transaction history for %s", address));
+						}
+
+						if (!historicTransactionHashes.isEmpty()) {
+							// Fully spent key - case (a)
+							this.bitcoiny.spentKeys.add(key);
+							this.wallet.getActiveKeyChain().markKeyAsUsed((DeterministicKey) key);
+							areAllKeysUnspent = false;
+						} else {
+							// Key never been used - case (b)
+						}
+
+						continue;
+					}
+
+					// If we reach here, then there's definitely at least one unspent key
+					this.bitcoiny.spentKeys.remove(key);
+
+					for (UnspentOutput unspentOutput : unspentOutputs) {
+						List<TransactionOutput> transactionOutputs;
+						try {
+							transactionOutputs = this.bitcoiny.getOutputs(unspentOutput.hash);
+						} catch (ForeignBlockchainException e) {
+							throw new UTXOProviderException(String.format("Unable to fetch outputs for TX %s",
+									HashCode.fromBytes(unspentOutput.hash)));
+						}
+
+						TransactionOutput transactionOutput = transactionOutputs.get(unspentOutput.index);
+
+						UTXO utxo = new UTXO(Sha256Hash.wrap(unspentOutput.hash), unspentOutput.index,
+								Coin.valueOf(unspentOutput.value), unspentOutput.height, coinbase,
+								transactionOutput.getScriptPubKey());
+
+						allUnspentOutputs.add(utxo);
+					}
+				}
+
+				if (areAllKeysUnspent)
+					// No transactions for this batch of keys so assume we're done searching.
+					return allUnspentOutputs;
+
+				// Generate some more keys
+				keys.addAll(Bitcoiny.generateMoreKeys(this.keyChain));
+
+				// Process new keys
+			} while (true);
+		}
+
+		@Override
+		public int getChainHeadHeight() throws UTXOProviderException {
+			try {
+				return this.bitcoiny.blockchain.getCurrentHeight();
+			} catch (ForeignBlockchainException e) {
+				throw new UTXOProviderException("Unable to determine Bitcoiny chain height");
+			}
+		}
+
+		@Override
+		public NetworkParameters getParams() {
+			return this.bitcoiny.params;
+		}
+	}
+
+	// Utility methods for others
+
+	public static List<SimpleForeignTransaction> simplifyWalletTransactions(List<BitcoinyTransaction> transactions) {
+		// Sort by oldest timestamp first
+		transactions.sort(Comparator.comparingInt(t -> t.timestamp));
+
+		// Manual 2nd-level sort same-timestamp transactions so that a transaction's input comes first
+		int fromIndex = 0;
+		do {
+			int timestamp = transactions.get(fromIndex).timestamp;
+
+			int toIndex;
+			for (toIndex = fromIndex + 1; toIndex < transactions.size(); ++toIndex)
+				if (transactions.get(toIndex).timestamp != timestamp)
+					break;
+
+			// Process same-timestamp sub-list
+			List<BitcoinyTransaction> subList = transactions.subList(fromIndex, toIndex);
+
+			// Only if necessary
+			if (subList.size() > 1) {
+				// Quick index lookup
+				Map<String, Integer> indexByTxHash = subList.stream().collect(Collectors.toMap(t -> t.txHash, t -> t.timestamp));
+
+				int restartIndex = 0;
+				boolean isSorted;
+				do {
+					isSorted = true;
+
+					for (int ourIndex = restartIndex; ourIndex < subList.size(); ++ourIndex) {
+						BitcoinyTransaction ourTx = subList.get(ourIndex);
+
+						for (BitcoinyTransaction.Input input : ourTx.inputs) {
+							Integer inputIndex = indexByTxHash.get(input.outputTxHash);
+
+							if (inputIndex != null && inputIndex > ourIndex) {
+								// Input tx is currently after current tx, so swap
+								BitcoinyTransaction tmpTx = subList.get(inputIndex);
+								subList.set(inputIndex, ourTx);
+								subList.set(ourIndex, tmpTx);
+
+								// Update index lookup too
+								indexByTxHash.put(ourTx.txHash, inputIndex);
+								indexByTxHash.put(tmpTx.txHash, ourIndex);
+
+								if (isSorted)
+									restartIndex = Math.max(restartIndex, ourIndex);
+
+								isSorted = false;
+								break;
+							}
+						}
+					}
+				} while (!isSorted);
+			}
+
+			fromIndex = toIndex;
+		} while (fromIndex < transactions.size());
+
+		// Simplify
+		List<SimpleForeignTransaction> simpleTransactions = new ArrayList<>();
+
+		// Quick lookup of txs in our wallet
+		Set<String> walletTxHashes = transactions.stream().map(t -> t.txHash).collect(Collectors.toSet());
+
+		for (BitcoinyTransaction transaction : transactions) {
+			SimpleForeignTransaction.Builder builder = new SimpleForeignTransaction.Builder();
+			builder.txHash(transaction.txHash);
+			builder.timestamp(transaction.timestamp);
+
+			builder.isSentNotReceived(false);
+
+			for (BitcoinyTransaction.Input input : transaction.inputs) {
+				// TODO: add input via builder
+
+				if (walletTxHashes.contains(input.outputTxHash))
+					builder.isSentNotReceived(true);
+			}
+
+			for (BitcoinyTransaction.Output output : transaction.outputs)
+				builder.output(output.addresses, output.value);
+
+			simpleTransactions.add(builder.build());
+		}
+
+		return simpleTransactions;
+	}
+
+	// Utility methods for us
+
+	protected static List<DeterministicKey> generateMoreKeys(DeterministicKeyChain keyChain) {
+		int existingLeafKeyCount = keyChain.getLeafKeys().size();
+
+		// Increase lookahead size...
+		keyChain.setLookaheadSize(keyChain.getLookaheadSize() + Bitcoiny.WALLET_KEY_LOOKAHEAD_INCREMENT);
+		// ...and lookahead threshold (minimum number of keys to generate)...
+		keyChain.setLookaheadThreshold(0);
+		// ...so that this call will generate more keys
+		keyChain.maybeLookAhead();
+
+		// This returns *all* keys
+		List<DeterministicKey> allLeafKeys = keyChain.getLeafKeys();
+
+		// Only return newly generated keys
+		return allLeafKeys.subList(existingLeafKeyCount, allLeafKeys.size());
+	}
+
+	protected byte[] addressToScriptPubKey(String base58Address) {
+		Context.propagate(this.bitcoinjContext);
+		Address address = Address.fromString(this.params, base58Address);
+		return ScriptBuilder.createOutputScript(address).getProgram();
+	}
+
+	protected Wallet walletFromDeterministicKey58(String key58) {
+		DeterministicKey dKey = DeterministicKey.deserializeB58(null, key58, this.params);
+
+		if (dKey.hasPrivKey())
+			return Wallet.fromSpendingKeyB58(this.params, key58, DeterministicHierarchy.BIP32_STANDARDISATION_TIME_SECS);
+		else
+			return Wallet.fromWatchingKeyB58(this.params, key58, DeterministicHierarchy.BIP32_STANDARDISATION_TIME_SECS);
+	}
+
+}

src/main/java/org/qortal/crosschain/BitcoinyBlockchainProvider.java

@@ -0,0 +1,40 @@
+package org.qortal.crosschain;
+
+import java.util.List;
+
+public abstract class BitcoinyBlockchainProvider {
+
+	public static final boolean INCLUDE_UNCONFIRMED = true;
+	public static final boolean EXCLUDE_UNCONFIRMED = false;
+
+	/** Returns ID unique to bitcoiny network (e.g. "Litecoin-TEST3") */
+	public abstract String getNetId();
+
+	/** Returns current blockchain height. */
+	public abstract int getCurrentHeight() throws ForeignBlockchainException;
+
+	/** Returns a list of raw block headers, starting at <tt>startHeight</tt> (inclusive), up to <tt>count</tt> max. */
+	public abstract List<byte[]> getRawBlockHeaders(int startHeight, int count) throws ForeignBlockchainException;
+
+	/** Returns balance of address represented by <tt>scriptPubKey</tt>. */
+	public abstract long getConfirmedBalance(byte[] scriptPubKey) throws ForeignBlockchainException;
+
+	/** Returns raw, serialized, transaction bytes given <tt>txHash</tt>. */
+	public abstract byte[] getRawTransaction(String txHash) throws ForeignBlockchainException;
+
+	/** Returns raw, serialized, transaction bytes given <tt>txHash</tt>. */
+	public abstract byte[] getRawTransaction(byte[] txHash) throws ForeignBlockchainException;
+
+	/** Returns unpacked transaction given <tt>txHash</tt>. */
+	public abstract BitcoinyTransaction getTransaction(String txHash) throws ForeignBlockchainException;
+
+	/** Returns list of transaction hashes (and heights) for address represented by <tt>scriptPubKey</tt>, optionally including unconfirmed transactions. */
+	public abstract List<TransactionHash> getAddressTransactions(byte[] scriptPubKey, boolean includeUnconfirmed) throws ForeignBlockchainException;
+
+	/** Returns list of unspent transaction outputs for address represented by <tt>scriptPubKey</tt>, optionally including unconfirmed transactions. */
+	public abstract List<UnspentOutput> getUnspentOutputs(byte[] scriptPubKey, boolean includeUnconfirmed) throws ForeignBlockchainException;
+
+	/** Broadcasts raw, serialized, transaction bytes to network, returning success/failure. */
+	public abstract void broadcastTransaction(byte[] rawTransaction) throws ForeignBlockchainException;
+
+}

src/main/java/org/qortal/crosschain/BitcoinyHTLC.java

@@ -4,6 +4,7 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.function.Function;
@@ -29,7 +30,7 @@ import org.qortal.utils.BitTwiddling;
 import com.google.common.hash.HashCode;
 import com.google.common.primitives.Bytes;
 
-public class BTCP2SH {
+public class BitcoinyHTLC {
 
 	public enum Status {
 		UNFUNDED, FUNDING_IN_PROGRESS, FUNDED, REDEEM_IN_PROGRESS, REDEEMED, REFUND_IN_PROGRESS, REFUNDED
@@ -38,6 +39,34 @@ public class BTCP2SH {
 	public static final int SECRET_LENGTH = 32;
 	public static final int MIN_LOCKTIME = 1500000000;
 
+	public static final long NO_LOCKTIME_NO_RBF_SEQUENCE = 0xFFFFFFFFL;
+	public static final long LOCKTIME_NO_RBF_SEQUENCE = NO_LOCKTIME_NO_RBF_SEQUENCE - 1;
+
+	// Assuming node's trade-bot has no more than 100 entries?
+	private static final int MAX_CACHE_ENTRIES = 100;
+
+	// Max time-to-live for cache entries (milliseconds)
+	private static final long CACHE_TIMEOUT = 30_000L;
+
+	@SuppressWarnings("serial")
+	private static final Map<String, byte[]> SECRET_CACHE = new LinkedHashMap<>(MAX_CACHE_ENTRIES + 1, 0.75F, true) {
+		// This method is called just after a new entry has been added
+		@Override
+		public boolean removeEldestEntry(Map.Entry<String, byte[]> eldest) {
+			return size() > MAX_CACHE_ENTRIES;
+		}
+	};
+	private static final byte[] NO_SECRET_CACHE_ENTRY = new byte[0];
+
+	@SuppressWarnings("serial")
+	private static final Map<String, Status> STATUS_CACHE = new LinkedHashMap<>(MAX_CACHE_ENTRIES + 1, 0.75F, true) {
+		// This method is called just after a new entry has been added
+		@Override
+		public boolean removeEldestEntry(Map.Entry<String, Status> eldest) {
+			return size() > MAX_CACHE_ENTRIES;
+		}
+	};
+
 	/*
 	 * OP_TUCK (to copy public key to before signature)
 	 * OP_CHECKSIGVERIFY (sig & pubkey must verify or script fails)
@@ -62,24 +91,24 @@ public class BTCP2SH {
 	private static final byte[] redeemScript5 = HashCode.fromString("8768").asBytes(); // OP_EQUAL OP_ENDIF
 
 	/**
-	 * Returns Bitcoin redeemScript used for cross-chain trading.
+	 * Returns redeemScript used for cross-chain trading.
 	 * <p>
-	 * See comments in {@link BTCP2SH} for more details.
+	 * See comments in {@link BitcoinyHTLC} for more details.
 	 * 
 	 * @param refunderPubKeyHash 20-byte HASH160 of P2SH funder's public key, for refunding purposes
 	 * @param lockTime seconds-since-epoch threshold, after which P2SH funder can claim refund
 	 * @param redeemerPubKeyHash 20-byte HASH160 of P2SH redeemer's public key
-	 * @param secretHash 20-byte HASH160 of secret, used by P2SH redeemer to claim funds
-	 * @return
+	 * @param hashOfSecret 20-byte HASH160 of secret, used by P2SH redeemer to claim funds
 	 */
-	public static byte[] buildScript(byte[] refunderPubKeyHash, int lockTime, byte[] redeemerPubKeyHash, byte[] secretHash) {
+	public static byte[] buildScript(byte[] refunderPubKeyHash, int lockTime, byte[] redeemerPubKeyHash, byte[] hashOfSecret) {
 		return Bytes.concat(redeemScript1, refunderPubKeyHash, redeemScript2, BitTwiddling.toLEByteArray((int) (lockTime & 0xffffffffL)),
-				redeemScript3, redeemerPubKeyHash, redeemScript4, secretHash, redeemScript5);
+				redeemScript3, redeemerPubKeyHash, redeemScript4, hashOfSecret, redeemScript5);
 	}
 
 	/**
-	 * Builds a custom transaction to spend P2SH.
+	 * Builds a custom transaction to spend HTLC P2SH.
 	 * 
+	 * @param params blockchain network parameters
 	 * @param amount output amount, should be total of input amounts, less miner fees
 	 * @param spendKey key for signing transaction, and also where funds are 'sent' (output)
 	 * @param fundingOutput output from transaction that funded P2SH address
@@ -87,12 +116,11 @@ public class BTCP2SH {
 	 * @param lockTime (optional) transaction nLockTime, used in refund scenario
 	 * @param scriptSigBuilder function for building scriptSig using transaction input signature
 	 * @param outputPublicKeyHash PKH used to create P2PKH output
-	 * @return Signed Bitcoin transaction for spending P2SH
+	 * @return Signed transaction for spending P2SH
 	 */
-	public static Transaction buildP2shTransaction(Coin amount, ECKey spendKey, List<TransactionOutput> fundingOutputs, byte[] redeemScriptBytes,
+	public static Transaction buildP2shTransaction(NetworkParameters params, Coin amount, ECKey spendKey,
+			List<TransactionOutput> fundingOutputs, byte[] redeemScriptBytes,
 			Long lockTime, Function<byte[], Script> scriptSigBuilder, byte[] outputPublicKeyHash) {
-		NetworkParameters params = BTC.getInstance().getNetworkParameters();
-
 		Transaction transaction = new Transaction(params);
 		transaction.setVersion(2);
 
@@ -105,9 +133,9 @@ public class BTCP2SH {
 			// Input (without scriptSig prior to signing)
 			TransactionInput input = new TransactionInput(params, null, redeemScriptBytes, fundingOutput.getOutPointFor());
 			if (lockTime != null)
-				input.setSequenceNumber(BTC.LOCKTIME_NO_RBF_SEQUENCE); // Use max-value - 1, so lockTime can be used but not RBF
+				input.setSequenceNumber(LOCKTIME_NO_RBF_SEQUENCE); // Use max-value - 1, so lockTime can be used but not RBF
 			else
-				input.setSequenceNumber(BTC.NO_LOCKTIME_NO_RBF_SEQUENCE); // Use max-value, so no lockTime and no RBF
+				input.setSequenceNumber(NO_LOCKTIME_NO_RBF_SEQUENCE); // Use max-value, so no lockTime and no RBF
 			transaction.addInput(input);
 		}
 
@@ -134,17 +162,19 @@ public class BTCP2SH {
 	}
 
 	/**
-	 * Returns signed Bitcoin transaction claiming refund from P2SH address.
+	 * Returns signed transaction claiming refund from HTLC P2SH.
 	 * 
+	 * @param params blockchain network parameters
 	 * @param refundAmount refund amount, should be total of input amounts, less miner fees
-	 * @param refundKey key for signing transaction, and also where refund is 'sent' (output)
-	 * @param fundingOutput output from transaction that funded P2SH address
+	 * @param refundKey key for signing transaction
+	 * @param fundingOutputs outputs from transaction that funded P2SH address
 	 * @param redeemScriptBytes the redeemScript itself, in byte[] form
 	 * @param lockTime transaction nLockTime - must be at least locktime used in redeemScript
-	 * @param receivingAccountInfo Bitcoin PKH used for output
-	 * @return Signed Bitcoin transaction for refunding P2SH
+	 * @param receivingAccountInfo public-key-hash used for P2PKH output
+	 * @return Signed transaction for refunding P2SH
 	 */
-	public static Transaction buildRefundTransaction(Coin refundAmount, ECKey refundKey, List<TransactionOutput> fundingOutputs, byte[] redeemScriptBytes, long lockTime, byte[] receivingAccountInfo) {
+	public static Transaction buildRefundTransaction(NetworkParameters params, Coin refundAmount, ECKey refundKey,
+			List<TransactionOutput> fundingOutputs, byte[] redeemScriptBytes, long lockTime, byte[] receivingAccountInfo) {
 		Function<byte[], Script> refundSigScriptBuilder = (txSigBytes) -> {
 			// Build scriptSig with...
 			ScriptBuilder scriptBuilder = new ScriptBuilder();
@@ -163,21 +193,23 @@ public class BTCP2SH {
 		};
 
 		// Send funds back to funding address
-		return buildP2shTransaction(refundAmount, refundKey, fundingOutputs, redeemScriptBytes, lockTime, refundSigScriptBuilder, receivingAccountInfo);
+		return buildP2shTransaction(params, refundAmount, refundKey, fundingOutputs, redeemScriptBytes, lockTime, refundSigScriptBuilder, receivingAccountInfo);
 	}
 
 	/**
-	 * Returns signed Bitcoin transaction redeeming funds from P2SH address.
+	 * Returns signed transaction redeeming funds from P2SH address.
 	 * 
+	 * @param params blockchain network parameters
 	 * @param redeemAmount redeem amount, should be total of input amounts, less miner fees
-	 * @param redeemKey key for signing transaction, and also where funds are 'sent' (output)
-	 * @param fundingOutput output from transaction that funded P2SH address
+	 * @param redeemKey key for signing transaction
+	 * @param fundingOutputs outputs from transaction that funded P2SH address
 	 * @param redeemScriptBytes the redeemScript itself, in byte[] form
 	 * @param secret actual 32-byte secret used when building redeemScript
 	 * @param receivingAccountInfo Bitcoin PKH used for output
-	 * @return Signed Bitcoin transaction for redeeming P2SH
+	 * @return Signed transaction for redeeming P2SH
 	 */
-	public static Transaction buildRedeemTransaction(Coin redeemAmount, ECKey redeemKey, List<TransactionOutput> fundingOutputs, byte[] redeemScriptBytes, byte[] secret, byte[] receivingAccountInfo) {
+	public static Transaction buildRedeemTransaction(NetworkParameters params, Coin redeemAmount, ECKey redeemKey,
+			List<TransactionOutput> fundingOutputs, byte[] redeemScriptBytes, byte[] secret, byte[] receivingAccountInfo) {
 		Function<byte[], Script> redeemSigScriptBuilder = (txSigBytes) -> {
 			// Build scriptSig with...
 			ScriptBuilder scriptBuilder = new ScriptBuilder();
@@ -198,17 +230,28 @@ public class BTCP2SH {
 			return scriptBuilder.build();
 		};
 
-		return buildP2shTransaction(redeemAmount, redeemKey, fundingOutputs, redeemScriptBytes, null, redeemSigScriptBuilder, receivingAccountInfo);
+		return buildP2shTransaction(params, redeemAmount, redeemKey, fundingOutputs, redeemScriptBytes, null, redeemSigScriptBuilder, receivingAccountInfo);
 	}
 
-	/** Returns 'secret', if any, given list of raw bitcoin transactions. */
-	public static byte[] findP2shSecret(String p2shAddress, List<byte[]> rawTransactions) {
-		NetworkParameters params = BTC.getInstance().getNetworkParameters();
+	/**
+	 * Returns 'secret', if any, given HTLC's P2SH address.
+	 * <p>
+	 * @throws ForeignBlockchainException
+	 */
+	public static byte[] findHtlcSecret(Bitcoiny bitcoiny, String p2shAddress) throws ForeignBlockchainException {
+		NetworkParameters params = bitcoiny.getNetworkParameters();
+		String compoundKey = String.format("%s-%s-%d", params.getId(), p2shAddress, System.currentTimeMillis() / CACHE_TIMEOUT);
+
+		byte[] secret = SECRET_CACHE.getOrDefault(compoundKey, NO_SECRET_CACHE_ENTRY);
+		if (secret != NO_SECRET_CACHE_ENTRY)
+			return secret;
+
+		List<byte[]> rawTransactions = bitcoiny.getAddressTransactions(p2shAddress);
 
 		for (byte[] rawTransaction : rawTransactions) {
 			Transaction transaction = new Transaction(params, rawTransaction);
 
-			// Cycle through inputs, looking for one that spends our P2SH
+			// Cycle through inputs, looking for one that spends our HTLC
 			for (TransactionInput input : transaction.getInputs()) {
 				Script scriptSig = input.getScriptSig();
 				List<ScriptChunk> scriptChunks = scriptSig.getChunks();
@@ -230,92 +273,115 @@ public class BTCP2SH {
 				Address inputAddress = LegacyAddress.fromScriptHash(params, redeemScriptHash);
 
 				if (!inputAddress.toString().equals(p2shAddress))
-					// Input isn't spending our P2SH
+					// Input isn't spending our HTLC
 					continue;
 
-				byte[] secret = scriptChunks.get(0).data;
-				if (secret.length != BTCP2SH.SECRET_LENGTH)
+				secret = scriptChunks.get(0).data;
+				if (secret.length != BitcoinyHTLC.SECRET_LENGTH)
 					continue;
 
+				// Cache secret for a while
+				SECRET_CACHE.put(compoundKey, secret);
+
 				return secret;
 			}
 		}
 
+		// Cache negative result
+		SECRET_CACHE.put(compoundKey, null);
+
 		return null;
 	}
 
-	/** Returns P2SH status, given P2SH address and expected redeem/refund amount, or throws BitcoinException if error occurs. */
-	public static Status determineP2shStatus(String p2shAddress, long minimumAmount) throws BitcoinException {
-		final BTC btc = BTC.getInstance();
+	/**
+	 * Returns HTLC status, given P2SH address and expected redeem/refund amount
+	 * <p>
+	 * @throws ForeignBlockchainException if error occurs
+	 */
+	public static Status determineHtlcStatus(BitcoinyBlockchainProvider blockchain, String p2shAddress, long minimumAmount) throws ForeignBlockchainException {
+		String compoundKey = String.format("%s-%s-%d", blockchain.getNetId(), p2shAddress, System.currentTimeMillis() / CACHE_TIMEOUT);
 
-		List<TransactionHash> transactionHashes = btc.getAddressTransactions(p2shAddress, BTC.INCLUDE_UNCONFIRMED);
+		Status cachedStatus = STATUS_CACHE.getOrDefault(compoundKey, null);
+		if (cachedStatus != null)
+			return cachedStatus;
+
+		byte[] ourScriptPubKey = addressToScriptPubKey(p2shAddress);
+		List<TransactionHash> transactionHashes = blockchain.getAddressTransactions(ourScriptPubKey, BitcoinyBlockchainProvider.INCLUDE_UNCONFIRMED);
 
 		// Sort by confirmed first, followed by ascending height
 		transactionHashes.sort(TransactionHash.CONFIRMED_FIRST.thenComparing(TransactionHash::getHeight));
 
 		// Transaction cache
-		Map<String, BitcoinTransaction> transactionsByHash = new HashMap<>();
+		Map<String, BitcoinyTransaction> transactionsByHash = new HashMap<>();
 		// HASH160(redeem script) for this p2shAddress
 		byte[] ourRedeemScriptHash = addressToRedeemScriptHash(p2shAddress);
 
 		// Check for spends first, caching full transaction info as we progress just in case we don't return in this loop
 		for (TransactionHash transactionInfo : transactionHashes) {
-			BitcoinTransaction bitcoinTransaction = btc.getTransaction(transactionInfo.txHash);
+			BitcoinyTransaction bitcoinyTransaction = blockchain.getTransaction(transactionInfo.txHash);
 
 			// Cache for possible later reuse
-			transactionsByHash.put(transactionInfo.txHash, bitcoinTransaction);
+			transactionsByHash.put(transactionInfo.txHash, bitcoinyTransaction);
 
 			// Acceptable funding is one transaction output, so we're expecting only one input
-			if (bitcoinTransaction.inputs.size() != 1)
+			if (bitcoinyTransaction.inputs.size() != 1)
 				// Wrong number of inputs
 				continue;
 
-			String scriptSig = bitcoinTransaction.inputs.get(0).scriptSig;
+			String scriptSig = bitcoinyTransaction.inputs.get(0).scriptSig;
 
 			List<byte[]> scriptSigChunks = extractScriptSigChunks(HashCode.fromString(scriptSig).asBytes());
 			if (scriptSigChunks.size() < 3 || scriptSigChunks.size() > 4)
-				// Not spending one of these P2SH
+				// Not valid chunks for our form of HTLC
 				continue;
 
 			// Last chunk is redeem script
 			byte[] redeemScriptBytes = scriptSigChunks.get(scriptSigChunks.size() - 1);
 			byte[] redeemScriptHash = Crypto.hash160(redeemScriptBytes);
 			if (!Arrays.equals(redeemScriptHash, ourRedeemScriptHash))
-				// Not spending our specific P2SH
+				// Not spending our specific HTLC redeem script
 				continue;
 
-			// If we have 4 chunks, then secret is present
-			return scriptSigChunks.size() == 4
-					? (transactionInfo.height == 0 ? Status.REDEEM_IN_PROGRESS : Status.REDEEMED)
-					: (transactionInfo.height == 0 ? Status.REFUND_IN_PROGRESS : Status.REFUNDED);
+			if (scriptSigChunks.size() == 4)
+				// If we have 4 chunks, then secret is present, hence redeem
+				cachedStatus = transactionInfo.height == 0 ? Status.REDEEM_IN_PROGRESS : Status.REDEEMED;
+			else
+				cachedStatus = transactionInfo.height == 0 ? Status.REFUND_IN_PROGRESS : Status.REFUNDED;
+
+			STATUS_CACHE.put(compoundKey, cachedStatus);
+			return cachedStatus;
 		}
 
-		String ourScriptPubKey = HashCode.fromBytes(addressToScriptPubKey(p2shAddress)).toString();
+		String ourScriptPubKeyHex = HashCode.fromBytes(ourScriptPubKey).toString();
 
 		// Check for funding
 		for (TransactionHash transactionInfo : transactionHashes) {
-			BitcoinTransaction bitcoinTransaction = transactionsByHash.get(transactionInfo.txHash);
-			if (bitcoinTransaction == null)
+			BitcoinyTransaction bitcoinyTransaction = transactionsByHash.get(transactionInfo.txHash);
+			if (bitcoinyTransaction == null)
 				// Should be present in map!
-				throw new BitcoinException("Cached Bitcoin transaction now missing?");
+				throw new ForeignBlockchainException("Cached Bitcoin transaction now missing?");
 
 			// Check outputs for our specific P2SH
-			for (BitcoinTransaction.Output output : bitcoinTransaction.outputs) {
+			for (BitcoinyTransaction.Output output : bitcoinyTransaction.outputs) {
 				// Check amount
 				if (output.value < minimumAmount)
 					// Output amount too small (not taking fees into account)
 					continue;
 
-				String scriptPubKey = output.scriptPubKey;
-				if (!scriptPubKey.equals(ourScriptPubKey))
+				String scriptPubKeyHex = output.scriptPubKey;
+				if (!scriptPubKeyHex.equals(ourScriptPubKeyHex))
 					// Not funding our specific P2SH
 					continue;
 
-				return transactionInfo.height == 0 ? Status.FUNDING_IN_PROGRESS : Status.FUNDED;
+				cachedStatus = transactionInfo.height == 0 ? Status.FUNDING_IN_PROGRESS : Status.FUNDED;
+				STATUS_CACHE.put(compoundKey, cachedStatus);
+				return cachedStatus;
 			}
 		}
 
-		return Status.UNFUNDED;
+		cachedStatus = Status.UNFUNDED;
+		STATUS_CACHE.put(compoundKey, cachedStatus);
+		return cachedStatus;
 	}
 
 	private static List<byte[]> extractScriptSigChunks(byte[] scriptSigBytes) {

src/main/java/org/qortal/crosschain/BitcoinyTransaction.java

@@ -3,20 +3,43 @@ package org.qortal.crosschain;
 import java.util.List;
 import java.util.stream.Collectors;
 
-public class BitcoinTransaction {
+import javax.xml.bind.annotation.XmlAccessType;
+import javax.xml.bind.annotation.XmlAccessorType;
+import javax.xml.bind.annotation.XmlTransient;
+
+@XmlAccessorType(XmlAccessType.FIELD)
+public class BitcoinyTransaction {
 
 	public final String txHash;
+
+	@XmlTransient
 	public final int size;
+
+	@XmlTransient
 	public final int locktime;
+
 	// Not present if transaction is unconfirmed
 	public final Integer timestamp;
 
 	public static class Input {
+		@XmlTransient
 		public final String scriptSig;
+
+		@XmlTransient
 		public final int sequence;
+
 		public final String outputTxHash;
+
 		public final int outputVout;
 
+		// For JAXB
+		protected Input() {
+			this.scriptSig = null;
+			this.sequence = 0;
+			this.outputTxHash = null;
+			this.outputVout = 0;
+		}
+
 		public Input(String scriptSig, int sequence, String outputTxHash, int outputVout) {
 			this.scriptSig = scriptSig;
 			this.sequence = sequence;
@@ -29,15 +52,34 @@ public class BitcoinTransaction {
 					this.outputTxHash, this.outputVout, this.sequence, this.scriptSig);
 		}
 	}
+	@XmlTransient
 	public final List<Input> inputs;
 
 	public static class Output {
+		@XmlTransient
 		public final String scriptPubKey;
+
 		public final long value;
 
+		public final List<String> addresses;
+
+		// For JAXB
+		protected Output() {
+			this.scriptPubKey = null;
+			this.value = 0;
+			this.addresses = null;
+		}
+
 		public Output(String scriptPubKey, long value) {
 			this.scriptPubKey = scriptPubKey;
 			this.value = value;
+			this.addresses = null;
+		}
+
+		public Output(String scriptPubKey, long value, List<String> addresses) {
+			this.scriptPubKey = scriptPubKey;
+			this.value = value;
+			this.addresses = addresses;
 		}
 
 		public String toString() {
@@ -46,7 +88,20 @@ public class BitcoinTransaction {
 	}
 	public final List<Output> outputs;
 
-	public BitcoinTransaction(String txHash, int size, int locktime, Integer timestamp,
+	public final long totalAmount;
+
+	// For JAXB
+	protected BitcoinyTransaction() {
+		this.txHash = null;
+		this.size = 0;
+		this.locktime = 0;
+		this.timestamp = 0;
+		this.inputs = null;
+		this.outputs = null;
+		this.totalAmount = 0;
+	}
+
+	public BitcoinyTransaction(String txHash, int size, int locktime, Integer timestamp,
 			List<Input> inputs, List<Output> outputs) {
 		this.txHash = txHash;
 		this.size = size;
@@ -54,6 +109,8 @@ public class BitcoinTransaction {
 		this.timestamp = timestamp;
 		this.inputs = inputs;
 		this.outputs = outputs;
+
+		this.totalAmount = outputs.stream().map(output -> output.value).reduce(0L, Long::sum);
 	}
 
 	public String toString() {
@@ -67,4 +124,23 @@ public class BitcoinTransaction {
 				this.inputs.stream().map(Input::toString).collect(Collectors.joining(",\n\t\t")),
 				this.outputs.stream().map(Output::toString).collect(Collectors.joining(",\n\t\t")));
 	}
+
+	@Override
+	public boolean equals(Object other) {
+		if (other == this)
+			return true;
+
+		if (!(other instanceof BitcoinyTransaction))
+			return false;
+
+		BitcoinyTransaction otherTransaction = (BitcoinyTransaction) other;
+
+		return this.txHash.equals(otherTransaction.txHash);
+	}
+
+	@Override
+	public int hashCode() {
+		return this.txHash.hashCode();
+	}
+
 }

src/main/java/org/qortal/crosschain/ElectrumX.java

@@ -1,13 +1,17 @@
 package org.qortal.crosschain;
 
 import java.io.IOException;
+import java.math.BigDecimal;
 import java.net.InetSocketAddress;
 import java.net.Socket;
 import java.net.SocketAddress;
 import java.util.ArrayList;
 import java.util.Arrays;
-import java.util.HashMap;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.EnumMap;
 import java.util.HashSet;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.NoSuchElementException;
@@ -30,33 +34,25 @@ import org.qortal.crypto.TrustlessSSLSocketFactory;
 import com.google.common.hash.HashCode;
 import com.google.common.primitives.Bytes;
 
-/** ElectrumX network support for querying Bitcoin-related info like block headers, transaction outputs, etc. */
-public class ElectrumX {
+/** ElectrumX network support for querying Bitcoiny-related info like block headers, transaction outputs, etc. */
+public class ElectrumX extends BitcoinyBlockchainProvider {
 
 	private static final Logger LOGGER = LogManager.getLogger(ElectrumX.class);
 	private static final Random RANDOM = new Random();
 
 	private static final double MIN_PROTOCOL_VERSION = 1.2;
-
-	private static final int DEFAULT_TCP_PORT = 50001;
-	private static final int DEFAULT_SSL_PORT = 50002;
-
 	private static final int BLOCK_HEADER_LENGTH = 80;
 
-	private static final String MAIN_GENESIS_HASH = "000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f";
-	private static final String TEST3_GENESIS_HASH = "000000000933ea01ad0ee984209779baaec3ced90fa3f408719526f8d77f4943";
-	// We won't know REGTEST (i.e. local) genesis block hash
-
 	// "message": "daemon error: DaemonError({'code': -5, 'message': 'No such mempool or blockchain transaction. Use gettransaction for wallet transactions.'})"
 	private static final Pattern DAEMON_ERROR_REGEX = Pattern.compile("DaemonError\\(\\{.*'code': ?(-?[0-9]+).*\\}\\)\\z"); // Capture 'code' inside curly-brace content
 
-	// Key: Bitcoin network (e.g. "MAIN", "TEST3", "REGTEST"), value: ElectrumX instance
-	private static final Map<String, ElectrumX> instances = new HashMap<>();
+	/** Error message sent by some ElectrumX servers when they don't support returning verbose transactions. */
+	private static final String VERBOSE_TRANSACTIONS_UNSUPPORTED_MESSAGE = "verbose transactions are currently unsupported";
 
-	private static class Server {
+	public static class Server {
 		String hostname;
 
-		enum ConnectionType { TCP, SSL }
+		public enum ConnectionType { TCP, SSL }
 		ConnectionType connectionType;
 
 		int port;
@@ -94,108 +90,61 @@ public class ElectrumX {
 	}
 	private Set<Server> servers = new HashSet<>();
 	private List<Server> remainingServers = new ArrayList<>();
+	private Set<Server> uselessServers = Collections.synchronizedSet(new HashSet<>());
 
-	private String expectedGenesisHash;
+	private final String netId;
+	private final String expectedGenesisHash;
+	private final Map<Server.ConnectionType, Integer> defaultPorts = new EnumMap<>(Server.ConnectionType.class);
+
+	private final Object serverLock = new Object();
 	private Server currentServer;
 	private Socket socket;
 	private Scanner scanner;
 	private int nextId = 1;
 
+	private static final int TX_CACHE_SIZE = 200;
+	@SuppressWarnings("serial")
+	private final Map<String, BitcoinyTransaction> transactionCache = Collections.synchronizedMap(new LinkedHashMap<>(TX_CACHE_SIZE + 1, 0.75F, true) {
+		// This method is called just after a new entry has been added
+		@Override
+		public boolean removeEldestEntry(Map.Entry<String, BitcoinyTransaction> eldest) {
+			return size() > TX_CACHE_SIZE;
+		}
+	});
+
 	// Constructors
 
-	private ElectrumX(String bitcoinNetwork) {
-		switch (bitcoinNetwork) {
-			case "MAIN":
-				this.expectedGenesisHash = MAIN_GENESIS_HASH;
-
-				this.servers.addAll(Arrays.asList(
-						// Servers chosen on NO BASIS WHATSOEVER from various sources!
-						new Server("enode.duckdns.org", Server.ConnectionType.SSL, 50002),
-						new Server("electrumx.ml", Server.ConnectionType.SSL, 50002),
-						new Server("electrum.bitkoins.nl", Server.ConnectionType.SSL, 50512),
-						new Server("btc.electroncash.dk", Server.ConnectionType.SSL, 60002),
-						new Server("electrumx.electricnewyear.net", Server.ConnectionType.SSL, 50002),
-						new Server("dxm.no-ip.biz", Server.ConnectionType.TCP, 50001),
-						new Server("kirsche.emzy.de", Server.ConnectionType.TCP, 50001),
-						new Server("2AZZARITA.hopto.org", Server.ConnectionType.TCP, 50001),
-						new Server("xtrum.com", Server.ConnectionType.TCP, 50001),
-						new Server("electrum.srvmin.network", Server.ConnectionType.TCP, 50001),
-						new Server("electrumx.alexridevski.net", Server.ConnectionType.TCP, 50001),
-						new Server("bitcoin.lukechilds.co", Server.ConnectionType.TCP, 50001),
-						new Server("electrum.poiuty.com", Server.ConnectionType.TCP, 50001),
-						new Server("horsey.cryptocowboys.net", Server.ConnectionType.TCP, 50001),
-						new Server("electrum.emzy.de", Server.ConnectionType.TCP, 50001),
-						new Server("electrum-server.ninja", Server.ConnectionType.TCP, 50081),
-						new Server("bitcoin.electrumx.multicoin.co", Server.ConnectionType.TCP, 50001),
-						new Server("esx.geekhosters.com", Server.ConnectionType.TCP, 50001),
-						new Server("bitcoin.grey.pw", Server.ConnectionType.TCP, 50003),
-						new Server("exs.ignorelist.com", Server.ConnectionType.TCP, 50001),
-						new Server("electrum.coinext.com.br", Server.ConnectionType.TCP, 50001),
-						new Server("bitcoin.aranguren.org", Server.ConnectionType.TCP, 50001),
-						new Server("skbxmit.coinjoined.com", Server.ConnectionType.TCP, 50001),
-						new Server("alviss.coinjoined.com", Server.ConnectionType.TCP, 50001),
-						new Server("electrum2.privateservers.network", Server.ConnectionType.TCP, 50001),
-						new Server("electrumx.schulzemic.net", Server.ConnectionType.TCP, 50001),
-						new Server("bitcoins.sk", Server.ConnectionType.TCP, 56001),
-						new Server("node.mendonca.xyz", Server.ConnectionType.TCP, 50001),
-						new Server("bitcoin.aranguren.org", Server.ConnectionType.TCP, 50001)));
-				break;
-
-			case "TEST3":
-				this.expectedGenesisHash = TEST3_GENESIS_HASH;
-
-				this.servers.addAll(Arrays.asList(
-						new Server("electrum.blockstream.info", Server.ConnectionType.TCP, 60001),
-						new Server("electrum.blockstream.info", Server.ConnectionType.SSL, 60002),
-						new Server("electrumx-test.1209k.com", Server.ConnectionType.SSL, 50002),
-						new Server("testnet.qtornado.com", Server.ConnectionType.TCP, 51001),
-						new Server("testnet.qtornado.com", Server.ConnectionType.SSL, 51002),
-						new Server("testnet.aranguren.org", Server.ConnectionType.TCP, 51001),
-						new Server("testnet.aranguren.org", Server.ConnectionType.SSL, 51002),
-						new Server("testnet.hsmiths.com", Server.ConnectionType.SSL, 53012)));
-				break;
-
-			case "REGTEST":
-				this.expectedGenesisHash = null;
-
-				this.servers.addAll(Arrays.asList(
-						new Server("localhost", Server.ConnectionType.TCP, DEFAULT_TCP_PORT),
-						new Server("localhost", Server.ConnectionType.SSL, DEFAULT_SSL_PORT)));
-				break;
-
-			default:
-				throw new IllegalArgumentException(String.format("Bitcoin network '%s' unknown", bitcoinNetwork));
-		}
-
-		LOGGER.debug(() -> String.format("Starting ElectrumX support for %s Bitcoin network", bitcoinNetwork));
-	}
-
-	/** Returns ElectrumX instance linked to passed Bitcoin network, one of "MAIN", "TEST3" or "REGTEST". */
-	public static synchronized ElectrumX getInstance(String bitcoinNetwork) {
-		if (!instances.containsKey(bitcoinNetwork))
-			instances.put(bitcoinNetwork, new ElectrumX(bitcoinNetwork));
-
-		return instances.get(bitcoinNetwork);
+	public ElectrumX(String netId, String genesisHash, Collection<Server> initialServerList, Map<Server.ConnectionType, Integer> defaultPorts) {
+		this.netId = netId;
+		this.expectedGenesisHash = genesisHash;
+		this.servers.addAll(initialServerList);
+		this.defaultPorts.putAll(defaultPorts);
 	}
 
 	// Methods for use by other classes
 
+	@Override
+	public String getNetId() {
+		return this.netId;
+	}
+
 	/**
 	 * Returns current blockchain height.
 	 * <p>
-	 * @throws BitcoinException if error occurs
+	 * @throws ForeignBlockchainException if error occurs
 	 */
-	public int getCurrentHeight() throws BitcoinException {
+	@Override
+	public int getCurrentHeight() throws ForeignBlockchainException {
 		Object blockObj = this.rpc("blockchain.headers.subscribe");
 		if (!(blockObj instanceof JSONObject))
-			throw new BitcoinException.NetworkException("Unexpected output from ElectrumX blockchain.headers.subscribe RPC");
+			throw new ForeignBlockchainException.NetworkException("Unexpected output from ElectrumX blockchain.headers.subscribe RPC");
 
 		JSONObject blockJson = (JSONObject) blockObj;
 
 		Object heightObj = blockJson.get("height");
 
 		if (!(heightObj instanceof Long))
-			throw new BitcoinException.NetworkException("Missing/invalid 'height' in JSON from ElectrumX blockchain.headers.subscribe RPC");
+			throw new ForeignBlockchainException.NetworkException("Missing/invalid 'height' in JSON from ElectrumX blockchain.headers.subscribe RPC");
 
 		return ((Long) heightObj).intValue();
 	}
@@ -203,12 +152,13 @@ public class ElectrumX {
 	/**
 	 * Returns list of raw block headers, starting from <tt>startHeight</tt> inclusive.
 	 * <p>
-	 * @throws BitcoinException if error occurs
+	 * @throws ForeignBlockchainException if error occurs
 	 */
-	public List<byte[]> getBlockHeaders(int startHeight, long count) throws BitcoinException {
+	@Override
+	public List<byte[]> getRawBlockHeaders(int startHeight, int count) throws ForeignBlockchainException {
 		Object blockObj = this.rpc("blockchain.block.headers", startHeight, count);
 		if (!(blockObj instanceof JSONObject))
-			throw new BitcoinException.NetworkException("Unexpected output from ElectrumX blockchain.block.headers RPC");
+			throw new ForeignBlockchainException.NetworkException("Unexpected output from ElectrumX blockchain.block.headers RPC");
 
 		JSONObject blockJson = (JSONObject) blockObj;
 
@@ -216,14 +166,14 @@ public class ElectrumX {
 		Object hexObj = blockJson.get("hex");
 
 		if (!(countObj instanceof Long) || !(hexObj instanceof String))
-			throw new BitcoinException.NetworkException("Missing/invalid 'count' or 'hex' entries in JSON from ElectrumX blockchain.block.headers RPC");
+			throw new ForeignBlockchainException.NetworkException("Missing/invalid 'count' or 'hex' entries in JSON from ElectrumX blockchain.block.headers RPC");
 
 		Long returnedCount = (Long) countObj;
 		String hex = (String) hexObj;
 
 		byte[] raw = HashCode.fromString(hex).asBytes();
 		if (raw.length != returnedCount * BLOCK_HEADER_LENGTH)
-			throw new BitcoinException.NetworkException("Unexpected raw header length in JSON from ElectrumX blockchain.block.headers RPC");
+			throw new ForeignBlockchainException.NetworkException("Unexpected raw header length in JSON from ElectrumX blockchain.block.headers RPC");
 
 		List<byte[]> rawBlockHeaders = new ArrayList<>(returnedCount.intValue());
 		for (int i = 0; i < returnedCount; ++i)
@@ -236,22 +186,23 @@ public class ElectrumX {
 	 * Returns confirmed balance, based on passed payment script.
 	 * <p>
 	 * @return confirmed balance, or zero if script unknown
-	 * @throws BitcoinException if there was an error
+	 * @throws ForeignBlockchainException if there was an error
 	 */
-	public long getConfirmedBalance(byte[] script) throws BitcoinException {
+	@Override
+	public long getConfirmedBalance(byte[] script) throws ForeignBlockchainException {
 		byte[] scriptHash = Crypto.digest(script);
 		Bytes.reverse(scriptHash);
 
 		Object balanceObj = this.rpc("blockchain.scripthash.get_balance", HashCode.fromBytes(scriptHash).toString());
 		if (!(balanceObj instanceof JSONObject))
-			throw new BitcoinException.NetworkException("Unexpected output from ElectrumX blockchain.scripthash.get_balance RPC");
+			throw new ForeignBlockchainException.NetworkException("Unexpected output from ElectrumX blockchain.scripthash.get_balance RPC");
 
 		JSONObject balanceJson = (JSONObject) balanceObj;
 
 		Object confirmedBalanceObj = balanceJson.get("confirmed");
 
 		if (!(confirmedBalanceObj instanceof Long))
-			throw new BitcoinException.NetworkException("Missing confirmed balance from ElectrumX blockchain.scripthash.get_balance RPC");
+			throw new ForeignBlockchainException.NetworkException("Missing confirmed balance from ElectrumX blockchain.scripthash.get_balance RPC");
 
 		return (Long) balanceJson.get("confirmed");
 	}
@@ -260,15 +211,16 @@ public class ElectrumX {
 	 * Returns list of unspent outputs pertaining to passed payment script.
 	 * <p>
 	 * @return list of unspent outputs, or empty list if script unknown
-	 * @throws BitcoinException if there was an error.
+	 * @throws ForeignBlockchainException if there was an error.
 	 */
-	public List<UnspentOutput> getUnspentOutputs(byte[] script, boolean includeUnconfirmed) throws BitcoinException {
+	@Override
+	public List<UnspentOutput> getUnspentOutputs(byte[] script, boolean includeUnconfirmed) throws ForeignBlockchainException {
 		byte[] scriptHash = Crypto.digest(script);
 		Bytes.reverse(scriptHash);
 
 		Object unspentJson = this.rpc("blockchain.scripthash.listunspent", HashCode.fromBytes(scriptHash).toString());
 		if (!(unspentJson instanceof JSONArray))
-			throw new BitcoinException("Expected array output from ElectrumX blockchain.scripthash.listunspent RPC");
+			throw new ForeignBlockchainException("Expected array output from ElectrumX blockchain.scripthash.listunspent RPC");
 
 		List<UnspentOutput> unspentOutputs = new ArrayList<>();
 		for (Object rawUnspent : (JSONArray) unspentJson) {
@@ -292,57 +244,93 @@ public class ElectrumX {
 	/**
 	 * Returns raw transaction for passed transaction hash.
 	 * <p>
-	 * @throws BitcoinException.NotFoundException if transaction not found
-	 * @throws BitcoinException if error occurs
+	 * NOTE: Do not mutate returned byte[]!
+	 * 
+	 * @throws ForeignBlockchainException.NotFoundException if transaction not found
+	 * @throws ForeignBlockchainException if error occurs
 	 */
-	public byte[] getRawTransaction(byte[] txHash) throws BitcoinException {
+	@Override
+	public byte[] getRawTransaction(String txHash) throws ForeignBlockchainException {
 		Object rawTransactionHex;
 		try {
-			rawTransactionHex = this.rpc("blockchain.transaction.get", HashCode.fromBytes(txHash).toString());
-		} catch (BitcoinException.NetworkException e) {
+			rawTransactionHex = this.rpc("blockchain.transaction.get", txHash, false);
+		} catch (ForeignBlockchainException.NetworkException e) {
 			// DaemonError({'code': -5, 'message': 'No such mempool or blockchain transaction. Use gettransaction for wallet transactions.'})
 			if (Integer.valueOf(-5).equals(e.getDaemonErrorCode()))
-				throw new BitcoinException.NotFoundException(e.getMessage());
+				throw new ForeignBlockchainException.NotFoundException(e.getMessage());
 
 			throw e;
 		}
 
 		if (!(rawTransactionHex instanceof String))
-			throw new BitcoinException.NetworkException("Expected hex string as raw transaction from ElectrumX blockchain.transaction.get RPC");
+			throw new ForeignBlockchainException.NetworkException("Expected hex string as raw transaction from ElectrumX blockchain.transaction.get RPC");
 
 		return HashCode.fromString((String) rawTransactionHex).asBytes();
 	}
 
+	/**
+	 * Returns raw transaction for passed transaction hash.
+	 * <p>
+	 * NOTE: Do not mutate returned byte[]!
+	 * 
+	 * @throws ForeignBlockchainException.NotFoundException if transaction not found
+	 * @throws ForeignBlockchainException if error occurs
+	 */
+	@Override
+	public byte[] getRawTransaction(byte[] txHash) throws ForeignBlockchainException {
+		return getRawTransaction(HashCode.fromBytes(txHash).toString());
+	}
+
 	/**
 	 * Returns transaction info for passed transaction hash.
 	 * <p>
-	 * @throws BitcoinException.NotFoundException if transaction not found
-	 * @throws BitcoinException if error occurs
+	 * @throws ForeignBlockchainException.NotFoundException if transaction not found
+	 * @throws ForeignBlockchainException if error occurs
 	 */
-	public BitcoinTransaction getTransaction(String txHash) throws BitcoinException {
-		Object transactionObj;
-		try {
-			transactionObj = this.rpc("blockchain.transaction.get", txHash, true);
-		} catch (BitcoinException.NetworkException e) {
-			// DaemonError({'code': -5, 'message': 'No such mempool or blockchain transaction. Use gettransaction for wallet transactions.'})
-			if (Integer.valueOf(-5).equals(e.getDaemonErrorCode()))
-				throw new BitcoinException.NotFoundException(e.getMessage());
+	@Override
+	public BitcoinyTransaction getTransaction(String txHash) throws ForeignBlockchainException {
+		// Check cache first
+		BitcoinyTransaction transaction = transactionCache.get(txHash);
+		if (transaction != null)
+			return transaction;
 
-			throw e;
-		}
+		Object transactionObj = null;
+
+		do {
+			try {
+				transactionObj = this.rpc("blockchain.transaction.get", txHash, true);
+			} catch (ForeignBlockchainException.NetworkException e) {
+				// DaemonError({'code': -5, 'message': 'No such mempool or blockchain transaction. Use gettransaction for wallet transactions.'})
+				if (Integer.valueOf(-5).equals(e.getDaemonErrorCode()))
+					throw new ForeignBlockchainException.NotFoundException(e.getMessage());
+
+				// Some servers also return non-standard responses like this:
+				// {"error":"verbose transactions are currently unsupported","id":3,"jsonrpc":"2.0"}
+				// We should probably not use this server any more
+				if (e.getServer() != null && e.getMessage() != null && e.getMessage().contains(VERBOSE_TRANSACTIONS_UNSUPPORTED_MESSAGE)) {
+					Server uselessServer = (Server) e.getServer();
+					LOGGER.trace(() -> String.format("Server %s doesn't support verbose transactions - barring use of that server", uselessServer));
+					this.uselessServers.add(uselessServer);
+					this.closeServer(uselessServer);
+					continue;
+				}
+
+				throw e;
+			}
+		} while (transactionObj == null);
 
 		if (!(transactionObj instanceof JSONObject))
-			throw new BitcoinException.NetworkException("Expected JSONObject as response from ElectrumX blockchain.transaction.get RPC");
+			throw new ForeignBlockchainException.NetworkException("Expected JSONObject as response from ElectrumX blockchain.transaction.get RPC");
 
 		JSONObject transactionJson = (JSONObject) transactionObj;
 
 		Object inputsObj = transactionJson.get("vin");
 		if (!(inputsObj instanceof JSONArray))
-			throw new BitcoinException.NetworkException("Expected JSONArray for 'vin' from ElectrumX blockchain.transaction.get RPC");
+			throw new ForeignBlockchainException.NetworkException("Expected JSONArray for 'vin' from ElectrumX blockchain.transaction.get RPC");
 
 		Object outputsObj = transactionJson.get("vout");
 		if (!(outputsObj instanceof JSONArray))
-			throw new BitcoinException.NetworkException("Expected JSONArray for 'vout' from ElectrumX blockchain.transaction.get RPC");
+			throw new ForeignBlockchainException.NetworkException("Expected JSONArray for 'vout' from ElectrumX blockchain.transaction.get RPC");
 
 		try {
 			int size = ((Long) transactionJson.get("size")).intValue();
@@ -354,7 +342,7 @@ public class ElectrumX {
 					? ((Long) timeObj).intValue()
 					: null;
 
-			List<BitcoinTransaction.Input> inputs = new ArrayList<>();
+			List<BitcoinyTransaction.Input> inputs = new ArrayList<>();
 			for (Object inputObj : (JSONArray) inputsObj) {
 				JSONObject inputJson = (JSONObject) inputObj;
 
@@ -363,40 +351,55 @@ public class ElectrumX {
 				String outputTxHash = (String) inputJson.get("txid");
 				int outputVout = ((Long) inputJson.get("vout")).intValue();
 
-				inputs.add(new BitcoinTransaction.Input(scriptSig, sequence, outputTxHash, outputVout));
+				inputs.add(new BitcoinyTransaction.Input(scriptSig, sequence, outputTxHash, outputVout));
 			}
 
-			List<BitcoinTransaction.Output> outputs = new ArrayList<>();
+			List<BitcoinyTransaction.Output> outputs = new ArrayList<>();
 			for (Object outputObj : (JSONArray) outputsObj) {
 				JSONObject outputJson = (JSONObject) outputObj;
 
 				String scriptPubKey = (String) ((JSONObject) outputJson.get("scriptPubKey")).get("hex");
-				long value = (long) (((Double) outputJson.get("value")) * 1e8);
+				long value = BigDecimal.valueOf((Double) outputJson.get("value")).setScale(8).unscaledValue().longValue();
 
-				outputs.add(new BitcoinTransaction.Output(scriptPubKey, value));
+				// address too, if present
+				List<String> addresses = null;
+				Object addressesObj = ((JSONObject) outputJson.get("scriptPubKey")).get("addresses");
+				if (addressesObj instanceof JSONArray) {
+					addresses = new ArrayList<>();
+					for (Object addressObj : (JSONArray) addressesObj)
+						addresses.add((String) addressObj);
+				}
+
+				outputs.add(new BitcoinyTransaction.Output(scriptPubKey, value, addresses));
 			}
 
-			return new BitcoinTransaction(txHash, size, locktime, timestamp, inputs, outputs);
+			transaction = new BitcoinyTransaction(txHash, size, locktime, timestamp, inputs, outputs);
+
+			// Save into cache
+			transactionCache.put(txHash, transaction);
+
+			return transaction;
 		} catch (NullPointerException | ClassCastException e) {
 			// Unexpected / invalid response from ElectrumX server
 		}
 
-		throw new BitcoinException.NetworkException("Unexpected JSON format from ElectrumX blockchain.transaction.get RPC");
+		throw new ForeignBlockchainException.NetworkException("Unexpected JSON format from ElectrumX blockchain.transaction.get RPC");
 	}
 
 	/**
 	 * Returns list of transactions, relating to passed payment script.
 	 * <p>
 	 * @return list of related transactions, or empty list if script unknown
-	 * @throws BitcoinException if error occurs
+	 * @throws ForeignBlockchainException if error occurs
 	 */
-	public List<TransactionHash> getAddressTransactions(byte[] script, boolean includeUnconfirmed) throws BitcoinException {
+	@Override
+	public List<TransactionHash> getAddressTransactions(byte[] script, boolean includeUnconfirmed) throws ForeignBlockchainException {
 		byte[] scriptHash = Crypto.digest(script);
 		Bytes.reverse(scriptHash);
 
 		Object transactionsJson = this.rpc("blockchain.scripthash.get_history", HashCode.fromBytes(scriptHash).toString());
 		if (!(transactionsJson instanceof JSONArray))
-			throw new BitcoinException.NetworkException("Expected array output from ElectrumX blockchain.scripthash.get_history RPC");
+			throw new ForeignBlockchainException.NetworkException("Expected array output from ElectrumX blockchain.scripthash.get_history RPC");
 
 		List<TransactionHash> transactionHashes = new ArrayList<>();
 
@@ -417,16 +420,17 @@ public class ElectrumX {
 	}
 
 	/**
-	 * Broadcasts raw transaction to Bitcoin network.
+	 * Broadcasts raw transaction to network.
 	 * <p>
-	 * @throws BitcoinException if error occurs
+	 * @throws ForeignBlockchainException if error occurs
 	 */
-	public void broadcastTransaction(byte[] transactionBytes) throws BitcoinException {
+	@Override
+	public void broadcastTransaction(byte[] transactionBytes) throws ForeignBlockchainException {
 		Object rawBroadcastResult = this.rpc("blockchain.transaction.broadcast", HashCode.fromBytes(transactionBytes).toString());
 
 		// We're expecting a simple string that is the transaction hash
 		if (!(rawBroadcastResult instanceof String))
-			throw new BitcoinException.NetworkException("Unexpected response from ElectrumX blockchain.transaction.broadcast RPC");
+			throw new ForeignBlockchainException.NetworkException("Unexpected response from ElectrumX blockchain.transaction.broadcast RPC");
 	}
 
 	// Class-private utility methods
@@ -434,10 +438,10 @@ public class ElectrumX {
 	/**
 	 * Query current server for its list of peer servers, and return those we can parse.
 	 * <p>
-	 * @throws BitcoinException
+	 * @throws ForeignBlockchainException
 	 * @throws ClassCastException to be handled by caller
 	 */
-	private Set<Server> serverPeersSubscribe() throws BitcoinException {
+	private Set<Server> serverPeersSubscribe() throws ForeignBlockchainException {
 		Set<Server> newServers = new HashSet<>();
 
 		Object peers = this.connectedRpc("server.peers.subscribe");
@@ -454,17 +458,17 @@ public class ElectrumX {
 			for (Object rawFeature : features) {
 				String feature = (String) rawFeature;
 				Server.ConnectionType connectionType = null;
-				int port = -1;
+				Integer port = null;
 
 				switch (feature.charAt(0)) {
 					case 's':
 						connectionType = Server.ConnectionType.SSL;
-						port = DEFAULT_SSL_PORT;
+						port = this.defaultPorts.get(connectionType);
 						break;
 
 					case 't':
 						connectionType = Server.ConnectionType.TCP;
-						port = DEFAULT_TCP_PORT;
+						port = this.defaultPorts.get(connectionType);
 						break;
 
 					default:
@@ -472,7 +476,7 @@ public class ElectrumX {
 						break;
 				}
 
-				if (connectionType == null)
+				if (connectionType == null || port == null)
 					// We couldn't extract any peer connection info?
 					continue;
 
@@ -497,32 +501,29 @@ public class ElectrumX {
 	 * Performs RPC call, with automatic reconnection to different server if needed.
 	 * <p>
 	 * @return "result" object from within JSON output
-	 * @throws BitcoinException if server returns error or something goes wrong
+	 * @throws ForeignBlockchainException if server returns error or something goes wrong
 	 */
-	private synchronized Object rpc(String method, Object...params) throws BitcoinException {
-		if (this.remainingServers.isEmpty())
-			this.remainingServers.addAll(this.servers);
+	private Object rpc(String method, Object...params) throws ForeignBlockchainException {
+		synchronized (this.serverLock) {
+			if (this.remainingServers.isEmpty())
+				this.remainingServers.addAll(this.servers);
 
-		while (haveConnection()) {
-			Object response = connectedRpc(method, params);
-			if (response != null)
-				return response;
+			while (haveConnection()) {
+				Object response = connectedRpc(method, params);
+				if (response != null)
+					return response;
 
-			this.currentServer = null;
-			try {
-				this.socket.close();
-			} catch (IOException e) {
-				/* ignore */
+				// Didn't work, try another server...
+				this.closeServer();
 			}
-			this.scanner = null;
-		}
 
-		// Failed to perform RPC - maybe lack of servers?
-		throw new BitcoinException.NetworkException("Failed to perform Bitcoin RPC");
+			// Failed to perform RPC - maybe lack of servers?
+			throw new ForeignBlockchainException.NetworkException(String.format("Failed to perform ElectrumX RPC %s", method));
+		}
 	}
 
 	/** Returns true if we have, or create, a connection to an ElectrumX server. */
-	private boolean haveConnection() throws BitcoinException {
+	private boolean haveConnection() throws ForeignBlockchainException {
 		if (this.currentServer != null)
 			return true;
 
@@ -566,17 +567,9 @@ public class ElectrumX {
 				LOGGER.debug(() -> String.format("Connected to %s", server));
 				this.currentServer = server;
 				return true;
-			} catch (IOException | BitcoinException | ClassCastException | NullPointerException e) {
-				// Try another server...
-				if (this.socket != null && !this.socket.isClosed())
-					try {
-						this.socket.close();
-					} catch (IOException e1) {
-						// We did try...
-					}
-
-				this.socket = null;
-				this.scanner = null;
+			} catch (IOException | ForeignBlockchainException | ClassCastException | NullPointerException e) {
+				// Didn't work, try another server...
+				closeServer();
 			}
 		}
 
@@ -589,10 +582,10 @@ public class ElectrumX {
 	 * @param method
 	 * @param params
 	 * @return response Object, or null if server fails to respond
-	 * @throws BitcoinException if server returns error
+	 * @throws ForeignBlockchainException if server returns error
 	 */
 	@SuppressWarnings("unchecked")
-	private Object connectedRpc(String method, Object...params) throws BitcoinException {
+	private Object connectedRpc(String method, Object...params) throws ForeignBlockchainException {
 		JSONObject requestJson = new JSONObject();
 		requestJson.put("id", this.nextId++);
 		requestJson.put("method", method);
@@ -630,15 +623,18 @@ public class ElectrumX {
 
 		Object errorObj = responseJson.get("error");
 		if (errorObj != null) {
+			if (errorObj instanceof String)
+				throw new ForeignBlockchainException.NetworkException(String.format("Unexpected error message from ElectrumX RPC %s: %s", method, (String) errorObj), this.currentServer);
+
 			if (!(errorObj instanceof JSONObject))
-				throw new BitcoinException.NetworkException(String.format("Unexpected error response from ElectrumX RPC %s", method));
+				throw new ForeignBlockchainException.NetworkException(String.format("Unexpected error response from ElectrumX RPC %s", method), this.currentServer);
 
 			JSONObject errorJson = (JSONObject) errorObj;
 
 			Object messageObj = errorJson.get("message");
 
 			if (!(messageObj instanceof String))
-				throw new BitcoinException.NetworkException(String.format("Missing/invalid message in error response from ElectrumX RPC %s", method));
+				throw new ForeignBlockchainException.NetworkException(String.format("Missing/invalid message in error response from ElectrumX RPC %s", method), this.currentServer);
 
 			String message = (String) messageObj;
 
@@ -649,15 +645,44 @@ public class ElectrumX {
 			if (messageMatcher.find())
 				try {
 					int daemonErrorCode = Integer.parseInt(messageMatcher.group(1));
-					throw new BitcoinException.NetworkException(daemonErrorCode, message);
+					throw new ForeignBlockchainException.NetworkException(daemonErrorCode, message, this.currentServer);
 				} catch (NumberFormatException e) {
 					// We couldn't parse the error code integer? Fall-through to generic exception...
 				}
 
-			throw new BitcoinException.NetworkException(message);
+			throw new ForeignBlockchainException.NetworkException(message, this.currentServer);
 		}
 
 		return responseJson.get("result");
 	}
 
+	/**
+	 * Closes connection to <tt>server</tt> if it is currently connected server.
+	 * @param server
+	 */
+	private void closeServer(Server server) {
+		synchronized (this.serverLock) {
+			if (this.currentServer == null || !this.currentServer.equals(server))
+				return;
+
+			if (this.socket != null && !this.socket.isClosed())
+				try {
+					this.socket.close();
+				} catch (IOException e) {
+					// We did try...
+				}
+
+			this.socket = null;
+			this.scanner = null;
+			this.currentServer = null;
+		}
+	}
+
+	/** Closes connection to currently connected server (if any). */
+	private void closeServer() {
+		synchronized (this.serverLock) {
+			this.closeServer(this.currentServer);
+		}
+	}
+
 }

src/main/java/org/qortal/crosschain/ForeignBlockchain.java

@@ -0,0 +1,9 @@
+package org.qortal.crosschain;
+
+public interface ForeignBlockchain {
+
+	public boolean isValidAddress(String address);
+
+	public boolean isValidWalletKey(String walletKey);
+
+}

src/main/java/org/qortal/crosschain/ForeignBlockchainException.java

@@ -0,0 +1,77 @@
+package org.qortal.crosschain;
+
+@SuppressWarnings("serial")
+public class ForeignBlockchainException extends Exception {
+
+	public ForeignBlockchainException() {
+		super();
+	}
+
+	public ForeignBlockchainException(String message) {
+		super(message);
+	}
+
+	public static class NetworkException extends ForeignBlockchainException {
+		private final Integer daemonErrorCode;
+		private final transient Object server;
+
+		public NetworkException() {
+			super();
+			this.daemonErrorCode = null;
+			this.server = null;
+		}
+
+		public NetworkException(String message) {
+			super(message);
+			this.daemonErrorCode = null;
+			this.server = null;
+		}
+
+		public NetworkException(int errorCode, String message) {
+			super(message);
+			this.daemonErrorCode = errorCode;
+			this.server = null;
+		}
+
+		public NetworkException(String message, Object server) {
+			super(message);
+			this.daemonErrorCode = null;
+			this.server = server;
+		}
+
+		public NetworkException(int errorCode, String message, Object server) {
+			super(message);
+			this.daemonErrorCode = errorCode;
+			this.server = server;
+		}
+
+		public Integer getDaemonErrorCode() {
+			return this.daemonErrorCode;
+		}
+
+		public Object getServer() {
+			return this.server;
+		}
+	}
+
+	public static class NotFoundException extends ForeignBlockchainException {
+		public NotFoundException() {
+			super();
+		}
+
+		public NotFoundException(String message) {
+			super(message);
+		}
+	}
+
+	public static class InsufficientFundsException extends ForeignBlockchainException {
+		public InsufficientFundsException() {
+			super();
+		}
+
+		public InsufficientFundsException(String message) {
+			super(message);
+		}
+	}
+
+}

src/main/java/org/qortal/crosschain/Litecoin.java

@@ -0,0 +1,175 @@
+package org.qortal.crosschain;
+
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.EnumMap;
+import java.util.Map;
+
+import org.bitcoinj.core.Coin;
+import org.bitcoinj.core.Context;
+import org.bitcoinj.core.NetworkParameters;
+import org.libdohj.params.LitecoinMainNetParams;
+import org.libdohj.params.LitecoinRegTestParams;
+import org.libdohj.params.LitecoinTestNet3Params;
+import org.qortal.crosschain.ElectrumX.Server;
+import org.qortal.crosschain.ElectrumX.Server.ConnectionType;
+import org.qortal.settings.Settings;
+
+public class Litecoin extends Bitcoiny {
+
+	public static final String CURRENCY_CODE = "LTC";
+
+	private static final Coin DEFAULT_FEE_PER_KB = Coin.valueOf(10000); // 0.0001 LTC per 1000 bytes
+
+	// Temporary values until a dynamic fee system is written.
+	private static final long MAINNET_FEE = 1000L;
+	private static final long NON_MAINNET_FEE = 1000L; // enough for TESTNET3 and should be OK for REGTEST
+
+	private static final Map<ElectrumX.Server.ConnectionType, Integer> DEFAULT_ELECTRUMX_PORTS = new EnumMap<>(ElectrumX.Server.ConnectionType.class);
+	static {
+		DEFAULT_ELECTRUMX_PORTS.put(ConnectionType.TCP, 50001);
+		DEFAULT_ELECTRUMX_PORTS.put(ConnectionType.SSL, 50002);
+	}
+
+	public enum LitecoinNet {
+		MAIN {
+			@Override
+			public NetworkParameters getParams() {
+				return LitecoinMainNetParams.get();
+			}
+
+			@Override
+			public Collection<ElectrumX.Server> getServers() {
+				return Arrays.asList(
+						// Servers chosen on NO BASIS WHATSOEVER from various sources!
+						new Server("electrum-ltc.someguy123.net", Server.ConnectionType.SSL, 50002),
+						new Server("backup.electrum-ltc.org", Server.ConnectionType.TCP, 50001),
+						new Server("backup.electrum-ltc.org", Server.ConnectionType.SSL, 443),
+						new Server("electrum.ltc.xurious.com", Server.ConnectionType.TCP, 50001),
+						new Server("electrum.ltc.xurious.com", Server.ConnectionType.SSL, 50002),
+						new Server("electrum-ltc.bysh.me", Server.ConnectionType.SSL, 50002),
+						new Server("ltc.rentonisk.com", Server.ConnectionType.TCP, 50001),
+						new Server("ltc.rentonisk.com", Server.ConnectionType.SSL, 50002),
+						new Server("electrum-ltc.petrkr.net", Server.ConnectionType.SSL, 60002),
+						new Server("ltc.litepay.ch", Server.ConnectionType.SSL, 50022));
+			}
+
+			@Override
+			public String getGenesisHash() {
+				return "12a765e31ffd4059bada1e25190f6e98c99d9714d334efa41a195a7e7e04bfe2";
+			}
+
+			@Override
+			public long getP2shFee(Long timestamp) {
+				// TODO: This will need to be replaced with something better in the near future!
+				return MAINNET_FEE;
+			}
+		},
+		TEST3 {
+			@Override
+			public NetworkParameters getParams() {
+				return LitecoinTestNet3Params.get();
+			}
+
+			@Override
+			public Collection<ElectrumX.Server> getServers() {
+				return Arrays.asList(
+						new Server("electrum-ltc.bysh.me", Server.ConnectionType.TCP, 51001),
+						new Server("electrum-ltc.bysh.me", Server.ConnectionType.SSL, 51002),
+						new Server("electrum.ltc.xurious.com", Server.ConnectionType.TCP, 51001),
+						new Server("electrum.ltc.xurious.com", Server.ConnectionType.SSL, 51002));
+			}
+
+			@Override
+			public String getGenesisHash() {
+				return "4966625a4b2851d9fdee139e56211a0d88575f59ed816ff5e6a63deb4e3e29a0";
+			}
+
+			@Override
+			public long getP2shFee(Long timestamp) {
+				return NON_MAINNET_FEE;
+			}
+		},
+		REGTEST {
+			@Override
+			public NetworkParameters getParams() {
+				return LitecoinRegTestParams.get();
+			}
+
+			@Override
+			public Collection<ElectrumX.Server> getServers() {
+				return Arrays.asList(
+						new Server("localhost", Server.ConnectionType.TCP, 50001),
+						new Server("localhost", Server.ConnectionType.SSL, 50002));
+			}
+
+			@Override
+			public String getGenesisHash() {
+				// This is unique to each regtest instance
+				return null;
+			}
+
+			@Override
+			public long getP2shFee(Long timestamp) {
+				return NON_MAINNET_FEE;
+			}
+		};
+
+		public abstract NetworkParameters getParams();
+		public abstract Collection<ElectrumX.Server> getServers();
+		public abstract String getGenesisHash();
+		public abstract long getP2shFee(Long timestamp) throws ForeignBlockchainException;
+	}
+
+	private static Litecoin instance;
+
+	private final LitecoinNet litecoinNet;
+
+	// Constructors and instance
+
+	private Litecoin(LitecoinNet litecoinNet, BitcoinyBlockchainProvider blockchain, Context bitcoinjContext, String currencyCode) {
+		super(blockchain, bitcoinjContext, currencyCode);
+		this.litecoinNet = litecoinNet;
+
+		LOGGER.info(() -> String.format("Starting Litecoin support using %s", this.litecoinNet.name()));
+	}
+
+	public static synchronized Litecoin getInstance() {
+		if (instance == null) {
+			LitecoinNet litecoinNet = Settings.getInstance().getLitecoinNet();
+
+			BitcoinyBlockchainProvider electrumX = new ElectrumX("Litecoin-" + litecoinNet.name(), litecoinNet.getGenesisHash(), litecoinNet.getServers(), DEFAULT_ELECTRUMX_PORTS);
+			Context bitcoinjContext = new Context(litecoinNet.getParams());
+
+			instance = new Litecoin(litecoinNet, electrumX, bitcoinjContext, CURRENCY_CODE);
+		}
+
+		return instance;
+	}
+
+	// Getters & setters
+
+	public static synchronized void resetForTesting() {
+		instance = null;
+	}
+
+	// Actual useful methods for use by other classes
+
+	/** Default Litecoin fee is lower than Bitcoin: only 10sats/byte. */
+	@Override
+	public Coin getFeePerKb() {
+		return DEFAULT_FEE_PER_KB;
+	}
+
+	/**
+	 * Returns estimated LTC fee, in sats per 1000bytes, optionally for historic timestamp.
+	 * 
+	 * @param timestamp optional milliseconds since epoch, or null for 'now'
+	 * @return sats per 1000bytes, or throws ForeignBlockchainException if something went wrong
+	 */
+	@Override
+	public long getP2shFee(Long timestamp) throws ForeignBlockchainException {
+		return this.litecoinNet.getP2shFee(timestamp);
+	}
+
+}

src/main/java/org/qortal/crosschain/LitecoinACCTv1.java

@@ -0,0 +1,853 @@
+package org.qortal.crosschain;
+
+import static org.ciyam.at.OpCode.calcOffset;
+
+import java.nio.ByteBuffer;
+import java.util.Arrays;
+import java.util.List;
+
+import org.ciyam.at.API;
+import org.ciyam.at.CompilationException;
+import org.ciyam.at.FunctionCode;
+import org.ciyam.at.MachineState;
+import org.ciyam.at.OpCode;
+import org.ciyam.at.Timestamp;
+import org.qortal.account.Account;
+import org.qortal.asset.Asset;
+import org.qortal.at.QortalFunctionCode;
+import org.qortal.crypto.Crypto;
+import org.qortal.data.at.ATData;
+import org.qortal.data.at.ATStateData;
+import org.qortal.data.crosschain.CrossChainTradeData;
+import org.qortal.data.transaction.MessageTransactionData;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.utils.Base58;
+import org.qortal.utils.BitTwiddling;
+
+import com.google.common.hash.HashCode;
+import com.google.common.primitives.Bytes;
+
+/**
+ * Cross-chain trade AT
+ * 
+ * <p>
+ * <ul>
+ * <li>Bob generates Litecoin & Qortal 'trade' keys
+ * 		<ul>
+ * 			<li>private key required to sign P2SH redeem tx</li>
+ * 			<li>private key could be used to create 'secret' (e.g. double-SHA256)</li>
+ * 			<li>encrypted private key could be stored in Qortal AT for access by Bob from any node</li>
+ * 		</ul>
+ * </li>
+ * <li>Bob deploys Qortal AT
+ * 		<ul>
+ * 		</ul>
+ * </li>
+ * <li>Alice finds Qortal AT and wants to trade
+ * 		<ul>
+ * 			<li>Alice generates Litecoin & Qortal 'trade' keys</li>
+ * 			<li>Alice funds Litecoin P2SH-A</li>
+ * 			<li>Alice sends 'offer' MESSAGE to Bob from her Qortal trade address, containing:
+ * 				<ul>
+ * 					<li>hash-of-secret-A</li>
+ * 					<li>her 'trade' Litecoin PKH</li>
+ * 				</ul>
+ * 			</li>
+ * 		</ul>
+ * </li>
+ * <li>Bob receives "offer" MESSAGE
+ * 		<ul>
+ * 			<li>Checks Alice's P2SH-A</li>
+ * 			<li>Sends 'trade' MESSAGE to Qortal AT from his trade address, containing:
+ * 				<ul>
+ * 					<li>Alice's trade Qortal address</li>
+ * 					<li>Alice's trade Litecoin PKH</li>
+ * 					<li>hash-of-secret-A</li>
+ * 				</ul>
+ * 			</li>
+ * 		</ul>
+ * </li>
+ * <li>Alice checks Qortal AT to confirm it's locked to her
+ * 		<ul>
+ * 			<li>Alice sends 'redeem' MESSAGE to Qortal AT from her trade address, containing:
+ * 				<ul>
+ * 					<li>secret-A</li>
+ * 					<li>Qortal receiving address of her chosing</li>
+ * 				</ul>
+ * 			</li>
+ * 			<li>AT's QORT funds are sent to Qortal receiving address</li>
+ * 		</ul>
+ * </li>
+ * <li>Bob checks AT, extracts secret-A
+ * 		<ul>
+ * 			<li>Bob redeems P2SH-A using his Litecoin trade key and secret-A</li>
+ * 			<li>P2SH-A LTC funds end up at Litecoin address determined by redeem transaction output(s)</li>
+ * 		</ul>
+ * </li>
+ * </ul>
+ */
+public class LitecoinACCTv1 implements ACCT {
+
+	public static final String NAME = LitecoinACCTv1.class.getSimpleName();
+	public static final byte[] CODE_BYTES_HASH = HashCode.fromString("0fb15ad9ad1867dfbcafa51155481aa15d984ff9506f2b428eca4e2a2feac2b3").asBytes(); // SHA256 of AT code bytes
+
+	public static final int SECRET_LENGTH = 32;
+
+	/** <b>Value</b> offset into AT segment where 'mode' variable (long) is stored. (Multiply by MachineState.VALUE_SIZE for byte offset). */
+	private static final int MODE_VALUE_OFFSET = 61;
+	/** <b>Byte</b> offset into AT state data where 'mode' variable (long) is stored. */
+	public static final int MODE_BYTE_OFFSET = MachineState.HEADER_LENGTH + (MODE_VALUE_OFFSET * MachineState.VALUE_SIZE);
+
+	public static class OfferMessageData {
+		public byte[] partnerLitecoinPKH;
+		public byte[] hashOfSecretA;
+		public long lockTimeA;
+	}
+	public static final int OFFER_MESSAGE_LENGTH = 20 /*partnerLitecoinPKH*/ + 20 /*hashOfSecretA*/ + 8 /*lockTimeA*/;
+	public static final int TRADE_MESSAGE_LENGTH = 32 /*partner's Qortal trade address (padded from 25 to 32)*/
+			+ 24 /*partner's Litecoin PKH (padded from 20 to 24)*/
+			+ 8 /*AT trade timeout (minutes)*/
+			+ 24 /*hash of secret-A (padded from 20 to 24)*/
+			+ 8 /*lockTimeA*/;
+	public static final int REDEEM_MESSAGE_LENGTH = 32 /*secret-A*/ + 32 /*partner's Qortal receiving address padded from 25 to 32*/;
+	public static final int CANCEL_MESSAGE_LENGTH = 32 /*AT creator's Qortal address*/;
+
+	private static LitecoinACCTv1 instance;
+
+	private LitecoinACCTv1() {
+	}
+
+	public static synchronized LitecoinACCTv1 getInstance() {
+		if (instance == null)
+			instance = new LitecoinACCTv1();
+
+		return instance;
+	}
+
+	@Override
+	public byte[] getCodeBytesHash() {
+		return CODE_BYTES_HASH;
+	}
+
+	@Override
+	public int getModeByteOffset() {
+		return MODE_BYTE_OFFSET;
+	}
+
+	@Override
+	public ForeignBlockchain getBlockchain() {
+		return Litecoin.getInstance();
+	}
+
+	/**
+	 * Returns Qortal AT creation bytes for cross-chain trading AT.
+	 * <p>
+	 * <tt>tradeTimeout</tt> (minutes) is the time window for the trade partner to send the
+	 * 32-byte secret to the AT, before the AT automatically refunds the AT's creator.
+	 * 
+	 * @param creatorTradeAddress AT creator's trade Qortal address
+	 * @param litecoinPublicKeyHash 20-byte HASH160 of creator's trade Litecoin public key
+	 * @param qortAmount how much QORT to pay trade partner if they send correct 32-byte secrets to AT
+	 * @param litecoinAmount how much LTC the AT creator is expecting to trade
+	 * @param tradeTimeout suggested timeout for entire trade
+	 */
+	public static byte[] buildQortalAT(String creatorTradeAddress, byte[] litecoinPublicKeyHash, long qortAmount, long litecoinAmount, int tradeTimeout) {
+		if (litecoinPublicKeyHash.length != 20)
+			throw new IllegalArgumentException("Litecoin public key hash should be 20 bytes");
+
+		// Labels for data segment addresses
+		int addrCounter = 0;
+
+		// Constants (with corresponding dataByteBuffer.put*() calls below)
+
+		final int addrCreatorTradeAddress1 = addrCounter++;
+		final int addrCreatorTradeAddress2 = addrCounter++;
+		final int addrCreatorTradeAddress3 = addrCounter++;
+		final int addrCreatorTradeAddress4 = addrCounter++;
+
+		final int addrLitecoinPublicKeyHash = addrCounter;
+		addrCounter += 4;
+
+		final int addrQortAmount = addrCounter++;
+		final int addrLitecoinAmount = addrCounter++;
+		final int addrTradeTimeout = addrCounter++;
+
+		final int addrMessageTxnType = addrCounter++;
+		final int addrExpectedTradeMessageLength = addrCounter++;
+		final int addrExpectedRedeemMessageLength = addrCounter++;
+
+		final int addrCreatorAddressPointer = addrCounter++;
+		final int addrQortalPartnerAddressPointer = addrCounter++;
+		final int addrMessageSenderPointer = addrCounter++;
+
+		final int addrTradeMessagePartnerLitecoinPKHOffset = addrCounter++;
+		final int addrPartnerLitecoinPKHPointer = addrCounter++;
+		final int addrTradeMessageHashOfSecretAOffset = addrCounter++;
+		final int addrHashOfSecretAPointer = addrCounter++;
+
+		final int addrRedeemMessageReceivingAddressOffset = addrCounter++;
+
+		final int addrMessageDataPointer = addrCounter++;
+		final int addrMessageDataLength = addrCounter++;
+
+		final int addrPartnerReceivingAddressPointer = addrCounter++;
+
+		final int addrEndOfConstants = addrCounter;
+
+		// Variables
+
+		final int addrCreatorAddress1 = addrCounter++;
+		final int addrCreatorAddress2 = addrCounter++;
+		final int addrCreatorAddress3 = addrCounter++;
+		final int addrCreatorAddress4 = addrCounter++;
+
+		final int addrQortalPartnerAddress1 = addrCounter++;
+		final int addrQortalPartnerAddress2 = addrCounter++;
+		final int addrQortalPartnerAddress3 = addrCounter++;
+		final int addrQortalPartnerAddress4 = addrCounter++;
+
+		final int addrLockTimeA = addrCounter++;
+		final int addrRefundTimeout = addrCounter++;
+		final int addrRefundTimestamp = addrCounter++;
+		final int addrLastTxnTimestamp = addrCounter++;
+		final int addrBlockTimestamp = addrCounter++;
+		final int addrTxnType = addrCounter++;
+		final int addrResult = addrCounter++;
+
+		final int addrMessageSender1 = addrCounter++;
+		final int addrMessageSender2 = addrCounter++;
+		final int addrMessageSender3 = addrCounter++;
+		final int addrMessageSender4 = addrCounter++;
+
+		final int addrMessageLength = addrCounter++;
+
+		final int addrMessageData = addrCounter;
+		addrCounter += 4;
+
+		final int addrHashOfSecretA = addrCounter;
+		addrCounter += 4;
+
+		final int addrPartnerLitecoinPKH = addrCounter;
+		addrCounter += 4;
+
+		final int addrPartnerReceivingAddress = addrCounter;
+		addrCounter += 4;
+
+		final int addrMode = addrCounter++;
+		assert addrMode == MODE_VALUE_OFFSET : String.format("addrMode %d does not match MODE_VALUE_OFFSET %d", addrMode, MODE_VALUE_OFFSET);
+
+		// Data segment
+		ByteBuffer dataByteBuffer = ByteBuffer.allocate(addrCounter * MachineState.VALUE_SIZE);
+
+		// AT creator's trade Qortal address, decoded from Base58
+		assert dataByteBuffer.position() == addrCreatorTradeAddress1 * MachineState.VALUE_SIZE : "addrCreatorTradeAddress1 incorrect";
+		byte[] creatorTradeAddressBytes = Base58.decode(creatorTradeAddress);
+		dataByteBuffer.put(Bytes.ensureCapacity(creatorTradeAddressBytes, 32, 0));
+
+		// Litecoin public key hash
+		assert dataByteBuffer.position() == addrLitecoinPublicKeyHash * MachineState.VALUE_SIZE : "addrLitecoinPublicKeyHash incorrect";
+		dataByteBuffer.put(Bytes.ensureCapacity(litecoinPublicKeyHash, 32, 0));
+
+		// Redeem Qort amount
+		assert dataByteBuffer.position() == addrQortAmount * MachineState.VALUE_SIZE : "addrQortAmount incorrect";
+		dataByteBuffer.putLong(qortAmount);
+
+		// Expected Litecoin amount
+		assert dataByteBuffer.position() == addrLitecoinAmount * MachineState.VALUE_SIZE : "addrLitecoinAmount incorrect";
+		dataByteBuffer.putLong(litecoinAmount);
+
+		// Suggested trade timeout (minutes)
+		assert dataByteBuffer.position() == addrTradeTimeout * MachineState.VALUE_SIZE : "addrTradeTimeout incorrect";
+		dataByteBuffer.putLong(tradeTimeout);
+
+		// We're only interested in MESSAGE transactions
+		assert dataByteBuffer.position() == addrMessageTxnType * MachineState.VALUE_SIZE : "addrMessageTxnType incorrect";
+		dataByteBuffer.putLong(API.ATTransactionType.MESSAGE.value);
+
+		// Expected length of 'trade' MESSAGE data from AT creator
+		assert dataByteBuffer.position() == addrExpectedTradeMessageLength * MachineState.VALUE_SIZE : "addrExpectedTradeMessageLength incorrect";
+		dataByteBuffer.putLong(TRADE_MESSAGE_LENGTH);
+
+		// Expected length of 'redeem' MESSAGE data from trade partner
+		assert dataByteBuffer.position() == addrExpectedRedeemMessageLength * MachineState.VALUE_SIZE : "addrExpectedRedeemMessageLength incorrect";
+		dataByteBuffer.putLong(REDEEM_MESSAGE_LENGTH);
+
+		// Index into data segment of AT creator's address, used by GET_B_IND
+		assert dataByteBuffer.position() == addrCreatorAddressPointer * MachineState.VALUE_SIZE : "addrCreatorAddressPointer incorrect";
+		dataByteBuffer.putLong(addrCreatorAddress1);
+
+		// Index into data segment of partner's Qortal address, used by SET_B_IND
+		assert dataByteBuffer.position() == addrQortalPartnerAddressPointer * MachineState.VALUE_SIZE : "addrQortalPartnerAddressPointer incorrect";
+		dataByteBuffer.putLong(addrQortalPartnerAddress1);
+
+		// Index into data segment of (temporary) transaction's sender's address, used by GET_B_IND
+		assert dataByteBuffer.position() == addrMessageSenderPointer * MachineState.VALUE_SIZE : "addrMessageSenderPointer incorrect";
+		dataByteBuffer.putLong(addrMessageSender1);
+
+		// Offset into 'trade' MESSAGE data payload for extracting partner's Litecoin PKH
+		assert dataByteBuffer.position() == addrTradeMessagePartnerLitecoinPKHOffset * MachineState.VALUE_SIZE : "addrTradeMessagePartnerLitecoinPKHOffset incorrect";
+		dataByteBuffer.putLong(32L);
+
+		// Index into data segment of partner's Litecoin PKH, used by GET_B_IND
+		assert dataByteBuffer.position() == addrPartnerLitecoinPKHPointer * MachineState.VALUE_SIZE : "addrPartnerLitecoinPKHPointer incorrect";
+		dataByteBuffer.putLong(addrPartnerLitecoinPKH);
+
+		// Offset into 'trade' MESSAGE data payload for extracting hash-of-secret-A
+		assert dataByteBuffer.position() == addrTradeMessageHashOfSecretAOffset * MachineState.VALUE_SIZE : "addrTradeMessageHashOfSecretAOffset incorrect";
+		dataByteBuffer.putLong(64L);
+
+		// Index into data segment to hash of secret A, used by GET_B_IND
+		assert dataByteBuffer.position() == addrHashOfSecretAPointer * MachineState.VALUE_SIZE : "addrHashOfSecretAPointer incorrect";
+		dataByteBuffer.putLong(addrHashOfSecretA);
+
+		// Offset into 'redeem' MESSAGE data payload for extracting Qortal receiving address
+		assert dataByteBuffer.position() == addrRedeemMessageReceivingAddressOffset * MachineState.VALUE_SIZE : "addrRedeemMessageReceivingAddressOffset incorrect";
+		dataByteBuffer.putLong(32L);
+
+		// Source location and length for hashing any passed secret
+		assert dataByteBuffer.position() == addrMessageDataPointer * MachineState.VALUE_SIZE : "addrMessageDataPointer incorrect";
+		dataByteBuffer.putLong(addrMessageData);
+		assert dataByteBuffer.position() == addrMessageDataLength * MachineState.VALUE_SIZE : "addrMessageDataLength incorrect";
+		dataByteBuffer.putLong(32L);
+
+		// Pointer into data segment of where to save partner's receiving Qortal address, used by GET_B_IND
+		assert dataByteBuffer.position() == addrPartnerReceivingAddressPointer * MachineState.VALUE_SIZE : "addrPartnerReceivingAddressPointer incorrect";
+		dataByteBuffer.putLong(addrPartnerReceivingAddress);
+
+		assert dataByteBuffer.position() == addrEndOfConstants * MachineState.VALUE_SIZE : "dataByteBuffer position not at end of constants";
+
+		// Code labels
+		Integer labelRefund = null;
+
+		Integer labelTradeTxnLoop = null;
+		Integer labelCheckTradeTxn = null;
+		Integer labelCheckCancelTxn = null;
+		Integer labelNotTradeNorCancelTxn = null;
+		Integer labelCheckNonRefundTradeTxn = null;
+		Integer labelTradeTxnExtract = null;
+		Integer labelRedeemTxnLoop = null;
+		Integer labelCheckRedeemTxn = null;
+		Integer labelCheckRedeemTxnSender = null;
+		Integer labelPayout = null;
+
+		ByteBuffer codeByteBuffer = ByteBuffer.allocate(768);
+
+		// Two-pass version
+		for (int pass = 0; pass < 2; ++pass) {
+			codeByteBuffer.clear();
+
+			try {
+				/* Initialization */
+
+				// Use AT creation 'timestamp' as starting point for finding transactions sent to AT
+				codeByteBuffer.put(OpCode.EXT_FUN_RET.compile(FunctionCode.GET_CREATION_TIMESTAMP, addrLastTxnTimestamp));
+
+				// Load B register with AT creator's address so we can save it into addrCreatorAddress1-4
+				codeByteBuffer.put(OpCode.EXT_FUN.compile(FunctionCode.PUT_CREATOR_INTO_B));
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(FunctionCode.GET_B_IND, addrCreatorAddressPointer));
+
+				// Set restart position to after this opcode
+				codeByteBuffer.put(OpCode.SET_PCS.compile());
+
+				/* Loop, waiting for message from AT creator's trade address containing trade partner details, or AT owner's address to cancel offer */
+
+				/* Transaction processing loop */
+				labelTradeTxnLoop = codeByteBuffer.position();
+
+				// Find next transaction (if any) to this AT since the last one (referenced by addrLastTxnTimestamp)
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(FunctionCode.PUT_TX_AFTER_TIMESTAMP_INTO_A, addrLastTxnTimestamp));
+				// If no transaction found, A will be zero. If A is zero, set addrResult to 1, otherwise 0.
+				codeByteBuffer.put(OpCode.EXT_FUN_RET.compile(FunctionCode.CHECK_A_IS_ZERO, addrResult));
+				// If addrResult is zero (i.e. A is non-zero, transaction was found) then go check transaction
+				codeByteBuffer.put(OpCode.BZR_DAT.compile(addrResult, calcOffset(codeByteBuffer, labelCheckTradeTxn)));
+				// Stop and wait for next block
+				codeByteBuffer.put(OpCode.STP_IMD.compile());
+
+				/* Check transaction */
+				labelCheckTradeTxn = codeByteBuffer.position();
+
+				// Update our 'last found transaction's timestamp' using 'timestamp' from transaction
+				codeByteBuffer.put(OpCode.EXT_FUN_RET.compile(FunctionCode.GET_TIMESTAMP_FROM_TX_IN_A, addrLastTxnTimestamp));
+				// Extract transaction type (message/payment) from transaction and save type in addrTxnType
+				codeByteBuffer.put(OpCode.EXT_FUN_RET.compile(FunctionCode.GET_TYPE_FROM_TX_IN_A, addrTxnType));
+				// If transaction type is not MESSAGE type then go look for another transaction
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrTxnType, addrMessageTxnType, calcOffset(codeByteBuffer, labelTradeTxnLoop)));
+
+				/* Check transaction's sender. We're expecting AT creator's trade address for 'trade' message, or AT creator's own address for 'cancel' message. */
+
+				// Extract sender address from transaction into B register
+				codeByteBuffer.put(OpCode.EXT_FUN.compile(FunctionCode.PUT_ADDRESS_FROM_TX_IN_A_INTO_B));
+				// Save B register into data segment starting at addrMessageSender1 (as pointed to by addrMessageSenderPointer)
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(FunctionCode.GET_B_IND, addrMessageSenderPointer));
+				// Compare each part of message sender's address with AT creator's trade address. If they don't match, check for cancel situation.
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender1, addrCreatorTradeAddress1, calcOffset(codeByteBuffer, labelCheckCancelTxn)));
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender2, addrCreatorTradeAddress2, calcOffset(codeByteBuffer, labelCheckCancelTxn)));
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender3, addrCreatorTradeAddress3, calcOffset(codeByteBuffer, labelCheckCancelTxn)));
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender4, addrCreatorTradeAddress4, calcOffset(codeByteBuffer, labelCheckCancelTxn)));
+				// Message sender's address matches AT creator's trade address so go process 'trade' message
+				codeByteBuffer.put(OpCode.JMP_ADR.compile(labelCheckNonRefundTradeTxn == null ? 0 : labelCheckNonRefundTradeTxn));
+
+				/* Checking message sender for possible cancel message */
+				labelCheckCancelTxn = codeByteBuffer.position();
+
+				// Compare each part of message sender's address with AT creator's address. If they don't match, look for another transaction.
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender1, addrCreatorAddress1, calcOffset(codeByteBuffer, labelNotTradeNorCancelTxn)));
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender2, addrCreatorAddress2, calcOffset(codeByteBuffer, labelNotTradeNorCancelTxn)));
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender3, addrCreatorAddress3, calcOffset(codeByteBuffer, labelNotTradeNorCancelTxn)));
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender4, addrCreatorAddress4, calcOffset(codeByteBuffer, labelNotTradeNorCancelTxn)));
+				// Partner address is AT creator's address, so cancel offer and finish.
+				codeByteBuffer.put(OpCode.SET_VAL.compile(addrMode, AcctMode.CANCELLED.value));
+				// We're finished forever (finishing auto-refunds remaining balance to AT creator)
+				codeByteBuffer.put(OpCode.FIN_IMD.compile());
+
+				/* Not trade nor cancel message */
+				labelNotTradeNorCancelTxn = codeByteBuffer.position();
+
+				// Loop to find another transaction
+				codeByteBuffer.put(OpCode.JMP_ADR.compile(labelTradeTxnLoop == null ? 0 : labelTradeTxnLoop));
+
+				/* Possible switch-to-trade-mode message */
+				labelCheckNonRefundTradeTxn = codeByteBuffer.position();
+
+				// Check 'trade' message we received has expected number of message bytes
+				codeByteBuffer.put(OpCode.EXT_FUN_RET.compile(QortalFunctionCode.GET_MESSAGE_LENGTH_FROM_TX_IN_A.value, addrMessageLength));
+				// If message length matches, branch to info extraction code
+				codeByteBuffer.put(OpCode.BEQ_DAT.compile(addrMessageLength, addrExpectedTradeMessageLength, calcOffset(codeByteBuffer, labelTradeTxnExtract)));
+				// Message length didn't match - go back to finding another 'trade' MESSAGE transaction
+				codeByteBuffer.put(OpCode.JMP_ADR.compile(labelTradeTxnLoop == null ? 0 : labelTradeTxnLoop));
+
+				/* Extracting info from 'trade' MESSAGE transaction */
+				labelTradeTxnExtract = codeByteBuffer.position();
+
+				// Extract message from transaction into B register
+				codeByteBuffer.put(OpCode.EXT_FUN.compile(FunctionCode.PUT_MESSAGE_FROM_TX_IN_A_INTO_B));
+				// Save B register into data segment starting at addrQortalPartnerAddress1 (as pointed to by addrQortalPartnerAddressPointer)
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(FunctionCode.GET_B_IND, addrQortalPartnerAddressPointer));
+
+				// Extract trade partner's Litecoin public key hash (PKH) from message into B
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(QortalFunctionCode.PUT_PARTIAL_MESSAGE_FROM_TX_IN_A_INTO_B.value, addrTradeMessagePartnerLitecoinPKHOffset));
+				// Store partner's Litecoin PKH (we only really use values from B1-B3)
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(FunctionCode.GET_B_IND, addrPartnerLitecoinPKHPointer));
+				// Extract AT trade timeout (minutes) (from B4)
+				codeByteBuffer.put(OpCode.EXT_FUN_RET.compile(FunctionCode.GET_B4, addrRefundTimeout));
+
+				// Grab next 32 bytes
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(QortalFunctionCode.PUT_PARTIAL_MESSAGE_FROM_TX_IN_A_INTO_B.value, addrTradeMessageHashOfSecretAOffset));
+
+				// Extract hash-of-secret-A (we only really use values from B1-B3)
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(FunctionCode.GET_B_IND, addrHashOfSecretAPointer));
+				// Extract lockTime-A (from B4)
+				codeByteBuffer.put(OpCode.EXT_FUN_RET.compile(FunctionCode.GET_B4, addrLockTimeA));
+
+				// Calculate trade timeout refund 'timestamp' by adding addrRefundTimeout minutes to this transaction's 'timestamp', then save into addrRefundTimestamp
+				codeByteBuffer.put(OpCode.EXT_FUN_RET_DAT_2.compile(FunctionCode.ADD_MINUTES_TO_TIMESTAMP, addrRefundTimestamp, addrLastTxnTimestamp, addrRefundTimeout));
+
+				/* We are in 'trade mode' */
+				codeByteBuffer.put(OpCode.SET_VAL.compile(addrMode, AcctMode.TRADING.value));
+
+				// Set restart position to after this opcode
+				codeByteBuffer.put(OpCode.SET_PCS.compile());
+
+				/* Loop, waiting for trade timeout or 'redeem' MESSAGE from Qortal trade partner */
+
+				// Fetch current block 'timestamp'
+				codeByteBuffer.put(OpCode.EXT_FUN_RET.compile(FunctionCode.GET_BLOCK_TIMESTAMP, addrBlockTimestamp));
+				// If we're not past refund 'timestamp' then look for next transaction
+				codeByteBuffer.put(OpCode.BLT_DAT.compile(addrBlockTimestamp, addrRefundTimestamp, calcOffset(codeByteBuffer, labelRedeemTxnLoop)));
+				// We're past refund 'timestamp' so go refund everything back to AT creator
+				codeByteBuffer.put(OpCode.JMP_ADR.compile(labelRefund == null ? 0 : labelRefund));
+
+				/* Transaction processing loop */
+				labelRedeemTxnLoop = codeByteBuffer.position();
+
+				// Find next transaction to this AT since the last one (if any)
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(FunctionCode.PUT_TX_AFTER_TIMESTAMP_INTO_A, addrLastTxnTimestamp));
+				// If no transaction found, A will be zero. If A is zero, set addrComparator to 1, otherwise 0.
+				codeByteBuffer.put(OpCode.EXT_FUN_RET.compile(FunctionCode.CHECK_A_IS_ZERO, addrResult));
+				// If addrResult is zero (i.e. A is non-zero, transaction was found) then go check transaction
+				codeByteBuffer.put(OpCode.BZR_DAT.compile(addrResult, calcOffset(codeByteBuffer, labelCheckRedeemTxn)));
+				// Stop and wait for next block
+				codeByteBuffer.put(OpCode.STP_IMD.compile());
+
+				/* Check transaction */
+				labelCheckRedeemTxn = codeByteBuffer.position();
+
+				// Update our 'last found transaction's timestamp' using 'timestamp' from transaction
+				codeByteBuffer.put(OpCode.EXT_FUN_RET.compile(FunctionCode.GET_TIMESTAMP_FROM_TX_IN_A, addrLastTxnTimestamp));
+				// Extract transaction type (message/payment) from transaction and save type in addrTxnType
+				codeByteBuffer.put(OpCode.EXT_FUN_RET.compile(FunctionCode.GET_TYPE_FROM_TX_IN_A, addrTxnType));
+				// If transaction type is not MESSAGE type then go look for another transaction
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrTxnType, addrMessageTxnType, calcOffset(codeByteBuffer, labelRedeemTxnLoop)));
+
+				/* Check message payload length */
+				codeByteBuffer.put(OpCode.EXT_FUN_RET.compile(QortalFunctionCode.GET_MESSAGE_LENGTH_FROM_TX_IN_A.value, addrMessageLength));
+				// If message length matches, branch to sender checking code
+				codeByteBuffer.put(OpCode.BEQ_DAT.compile(addrMessageLength, addrExpectedRedeemMessageLength, calcOffset(codeByteBuffer, labelCheckRedeemTxnSender)));
+				// Message length didn't match - go back to finding another 'redeem' MESSAGE transaction
+				codeByteBuffer.put(OpCode.JMP_ADR.compile(labelRedeemTxnLoop == null ? 0 : labelRedeemTxnLoop));
+
+				/* Check transaction's sender */
+				labelCheckRedeemTxnSender = codeByteBuffer.position();
+
+				// Extract sender address from transaction into B register
+				codeByteBuffer.put(OpCode.EXT_FUN.compile(FunctionCode.PUT_ADDRESS_FROM_TX_IN_A_INTO_B));
+				// Save B register into data segment starting at addrMessageSender1 (as pointed to by addrMessageSenderPointer)
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(FunctionCode.GET_B_IND, addrMessageSenderPointer));
+				// Compare each part of transaction's sender's address with expected address. If they don't match, look for another transaction.
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender1, addrQortalPartnerAddress1, calcOffset(codeByteBuffer, labelRedeemTxnLoop)));
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender2, addrQortalPartnerAddress2, calcOffset(codeByteBuffer, labelRedeemTxnLoop)));
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender3, addrQortalPartnerAddress3, calcOffset(codeByteBuffer, labelRedeemTxnLoop)));
+				codeByteBuffer.put(OpCode.BNE_DAT.compile(addrMessageSender4, addrQortalPartnerAddress4, calcOffset(codeByteBuffer, labelRedeemTxnLoop)));
+
+				/* Check 'secret-A' in transaction's message */
+
+				// Extract secret-A from first 32 bytes of message from transaction into B register
+				codeByteBuffer.put(OpCode.EXT_FUN.compile(FunctionCode.PUT_MESSAGE_FROM_TX_IN_A_INTO_B));
+				// Save B register into data segment starting at addrMessageData (as pointed to by addrMessageDataPointer)
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(FunctionCode.GET_B_IND, addrMessageDataPointer));
+				// Load B register with expected hash result (as pointed to by addrHashOfSecretAPointer)
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(FunctionCode.SET_B_IND, addrHashOfSecretAPointer));
+				// Perform HASH160 using source data at addrMessageData. (Location and length specified via addrMessageDataPointer and addrMessageDataLength).
+				// Save the equality result (1 if they match, 0 otherwise) into addrResult.
+				codeByteBuffer.put(OpCode.EXT_FUN_RET_DAT_2.compile(FunctionCode.CHECK_HASH160_WITH_B, addrResult, addrMessageDataPointer, addrMessageDataLength));
+				// If hashes don't match, addrResult will be zero so go find another transaction
+				codeByteBuffer.put(OpCode.BNZ_DAT.compile(addrResult, calcOffset(codeByteBuffer, labelPayout)));
+				codeByteBuffer.put(OpCode.JMP_ADR.compile(labelRedeemTxnLoop == null ? 0 : labelRedeemTxnLoop));
+
+				/* Success! Pay arranged amount to receiving address */
+				labelPayout = codeByteBuffer.position();
+
+				// Extract Qortal receiving address from next 32 bytes of message from transaction into B register
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(QortalFunctionCode.PUT_PARTIAL_MESSAGE_FROM_TX_IN_A_INTO_B.value, addrRedeemMessageReceivingAddressOffset));
+				// Save B register into data segment starting at addrPartnerReceivingAddress (as pointed to by addrPartnerReceivingAddressPointer)
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(FunctionCode.GET_B_IND, addrPartnerReceivingAddressPointer));
+				// Pay AT's balance to receiving address
+				codeByteBuffer.put(OpCode.EXT_FUN_DAT.compile(FunctionCode.PAY_TO_ADDRESS_IN_B, addrQortAmount));
+				// Set redeemed mode
+				codeByteBuffer.put(OpCode.SET_VAL.compile(addrMode, AcctMode.REDEEMED.value));
+				// We're finished forever (finishing auto-refunds remaining balance to AT creator)
+				codeByteBuffer.put(OpCode.FIN_IMD.compile());
+
+				// Fall-through to refunding any remaining balance back to AT creator
+
+				/* Refund balance back to AT creator */
+				labelRefund = codeByteBuffer.position();
+
+				// Set refunded mode
+				codeByteBuffer.put(OpCode.SET_VAL.compile(addrMode, AcctMode.REFUNDED.value));
+				// We're finished forever (finishing auto-refunds remaining balance to AT creator)
+				codeByteBuffer.put(OpCode.FIN_IMD.compile());
+			} catch (CompilationException e) {
+				throw new IllegalStateException("Unable to compile LTC-QORT ACCT?", e);
+			}
+		}
+
+		codeByteBuffer.flip();
+
+		byte[] codeBytes = new byte[codeByteBuffer.limit()];
+		codeByteBuffer.get(codeBytes);
+
+		assert Arrays.equals(Crypto.digest(codeBytes), LitecoinACCTv1.CODE_BYTES_HASH)
+			: String.format("BTCACCT.CODE_BYTES_HASH mismatch: expected %s, actual %s", HashCode.fromBytes(CODE_BYTES_HASH), HashCode.fromBytes(Crypto.digest(codeBytes)));
+
+		final short ciyamAtVersion = 2;
+		final short numCallStackPages = 0;
+		final short numUserStackPages = 0;
+		final long minActivationAmount = 0L;
+
+		return MachineState.toCreationBytes(ciyamAtVersion, codeBytes, dataByteBuffer.array(), numCallStackPages, numUserStackPages, minActivationAmount);
+	}
+
+	/**
+	 * Returns CrossChainTradeData with useful info extracted from AT.
+	 */
+	@Override
+	public CrossChainTradeData populateTradeData(Repository repository, ATData atData) throws DataException {
+		ATStateData atStateData = repository.getATRepository().getLatestATState(atData.getATAddress());
+		return populateTradeData(repository, atData.getCreatorPublicKey(), atData.getCreation(), atStateData);
+	}
+
+	/**
+	 * Returns CrossChainTradeData with useful info extracted from AT.
+	 */
+	@Override
+	public CrossChainTradeData populateTradeData(Repository repository, ATStateData atStateData) throws DataException {
+		ATData atData = repository.getATRepository().fromATAddress(atStateData.getATAddress());
+		return populateTradeData(repository, atData.getCreatorPublicKey(), atData.getCreation(), atStateData);
+	}
+
+	/**
+	 * Returns CrossChainTradeData with useful info extracted from AT.
+	 */
+	public CrossChainTradeData populateTradeData(Repository repository, byte[] creatorPublicKey, long creationTimestamp, ATStateData atStateData) throws DataException {
+		byte[] addressBytes = new byte[25]; // for general use
+		String atAddress = atStateData.getATAddress();
+
+		CrossChainTradeData tradeData = new CrossChainTradeData();
+
+		tradeData.foreignBlockchain = SupportedBlockchain.LITECOIN.name();
+		tradeData.acctName = NAME;
+
+		tradeData.qortalAtAddress = atAddress;
+		tradeData.qortalCreator = Crypto.toAddress(creatorPublicKey);
+		tradeData.creationTimestamp = creationTimestamp;
+
+		Account atAccount = new Account(repository, atAddress);
+		tradeData.qortBalance = atAccount.getConfirmedBalance(Asset.QORT);
+
+		byte[] stateData = atStateData.getStateData();
+		ByteBuffer dataByteBuffer = ByteBuffer.wrap(stateData);
+		dataByteBuffer.position(MachineState.HEADER_LENGTH);
+
+		/* Constants */
+
+		// Skip creator's trade address
+		dataByteBuffer.get(addressBytes);
+		tradeData.qortalCreatorTradeAddress = Base58.encode(addressBytes);
+		dataByteBuffer.position(dataByteBuffer.position() + 32 - addressBytes.length);
+
+		// Creator's Litecoin/foreign public key hash
+		tradeData.creatorForeignPKH = new byte[20];
+		dataByteBuffer.get(tradeData.creatorForeignPKH);
+		dataByteBuffer.position(dataByteBuffer.position() + 32 - tradeData.creatorForeignPKH.length); // skip to 32 bytes
+
+		// We don't use secret-B
+		tradeData.hashOfSecretB = null;
+
+		// Redeem payout
+		tradeData.qortAmount = dataByteBuffer.getLong();
+
+		// Expected LTC amount
+		tradeData.expectedForeignAmount = dataByteBuffer.getLong();
+
+		// Trade timeout
+		tradeData.tradeTimeout = (int) dataByteBuffer.getLong();
+
+		// Skip MESSAGE transaction type
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip expected 'trade' message length
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip expected 'redeem' message length
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip pointer to creator's address
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip pointer to partner's Qortal trade address
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip pointer to message sender
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip 'trade' message data offset for partner's Litecoin PKH
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip pointer to partner's Litecoin PKH
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip 'trade' message data offset for hash-of-secret-A
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip pointer to hash-of-secret-A
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip 'redeem' message data offset for partner's Qortal receiving address
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip pointer to message data
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip message data length
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip pointer to partner's receiving address
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		/* End of constants / begin variables */
+
+		// Skip AT creator's address
+		dataByteBuffer.position(dataByteBuffer.position() + 8 * 4);
+
+		// Partner's trade address (if present)
+		dataByteBuffer.get(addressBytes);
+		String qortalRecipient = Base58.encode(addressBytes);
+		dataByteBuffer.position(dataByteBuffer.position() + 32 - addressBytes.length);
+
+		// Potential lockTimeA (if in trade mode)
+		int lockTimeA = (int) dataByteBuffer.getLong();
+
+		// AT refund timeout (probably only useful for debugging)
+		int refundTimeout = (int) dataByteBuffer.getLong();
+
+		// Trade-mode refund timestamp (AT 'timestamp' converted to Qortal block height)
+		long tradeRefundTimestamp = dataByteBuffer.getLong();
+
+		// Skip last transaction timestamp
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip block timestamp
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip transaction type
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip temporary result
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip temporary message sender
+		dataByteBuffer.position(dataByteBuffer.position() + 8 * 4);
+
+		// Skip message length
+		dataByteBuffer.position(dataByteBuffer.position() + 8);
+
+		// Skip temporary message data
+		dataByteBuffer.position(dataByteBuffer.position() + 8 * 4);
+
+		// Potential hash160 of secret A
+		byte[] hashOfSecretA = new byte[20];
+		dataByteBuffer.get(hashOfSecretA);
+		dataByteBuffer.position(dataByteBuffer.position() + 32 - hashOfSecretA.length); // skip to 32 bytes
+
+		// Potential partner's Litecoin PKH
+		byte[] partnerLitecoinPKH = new byte[20];
+		dataByteBuffer.get(partnerLitecoinPKH);
+		dataByteBuffer.position(dataByteBuffer.position() + 32 - partnerLitecoinPKH.length); // skip to 32 bytes
+
+		// Partner's receiving address (if present)
+		byte[] partnerReceivingAddress = new byte[25];
+		dataByteBuffer.get(partnerReceivingAddress);
+		dataByteBuffer.position(dataByteBuffer.position() + 32 - partnerReceivingAddress.length); // skip to 32 bytes
+
+		// Trade AT's 'mode'
+		long modeValue = dataByteBuffer.getLong();
+		AcctMode mode = AcctMode.valueOf((int) (modeValue & 0xffL));
+
+		/* End of variables */
+
+		if (mode != null && mode != AcctMode.OFFERING) {
+			tradeData.mode = mode;
+			tradeData.refundTimeout = refundTimeout;
+			tradeData.tradeRefundHeight = new Timestamp(tradeRefundTimestamp).blockHeight;
+			tradeData.qortalPartnerAddress = qortalRecipient;
+			tradeData.hashOfSecretA = hashOfSecretA;
+			tradeData.partnerForeignPKH = partnerLitecoinPKH;
+			tradeData.lockTimeA = lockTimeA;
+
+			if (mode == AcctMode.REDEEMED)
+				tradeData.qortalPartnerReceivingAddress = Base58.encode(partnerReceivingAddress);
+		} else {
+			tradeData.mode = AcctMode.OFFERING;
+		}
+
+		tradeData.duplicateDeprecated();
+
+		return tradeData;
+	}
+
+	/** Returns 'offer' MESSAGE payload for trade partner to send to AT creator's trade address. */
+	public static byte[] buildOfferMessage(byte[] partnerBitcoinPKH, byte[] hashOfSecretA, int lockTimeA) {
+		byte[] lockTimeABytes = BitTwiddling.toBEByteArray((long) lockTimeA);
+		return Bytes.concat(partnerBitcoinPKH, hashOfSecretA, lockTimeABytes);
+	}
+
+	/** Returns info extracted from 'offer' MESSAGE payload sent by trade partner to AT creator's trade address, or null if not valid. */
+	public static OfferMessageData extractOfferMessageData(byte[] messageData) {
+		if (messageData == null || messageData.length != OFFER_MESSAGE_LENGTH)
+			return null;
+
+		OfferMessageData offerMessageData = new OfferMessageData();
+		offerMessageData.partnerLitecoinPKH = Arrays.copyOfRange(messageData, 0, 20);
+		offerMessageData.hashOfSecretA = Arrays.copyOfRange(messageData, 20, 40);
+		offerMessageData.lockTimeA = BitTwiddling.longFromBEBytes(messageData, 40);
+
+		return offerMessageData;
+	}
+
+	/** Returns 'trade' MESSAGE payload for AT creator to send to AT. */
+	public static byte[] buildTradeMessage(String partnerQortalTradeAddress, byte[] partnerBitcoinPKH, byte[] hashOfSecretA, int lockTimeA, int refundTimeout) {
+		byte[] data = new byte[TRADE_MESSAGE_LENGTH];
+		byte[] partnerQortalAddressBytes = Base58.decode(partnerQortalTradeAddress);
+		byte[] lockTimeABytes = BitTwiddling.toBEByteArray((long) lockTimeA);
+		byte[] refundTimeoutBytes = BitTwiddling.toBEByteArray((long) refundTimeout);
+
+		System.arraycopy(partnerQortalAddressBytes, 0, data, 0, partnerQortalAddressBytes.length);
+		System.arraycopy(partnerBitcoinPKH, 0, data, 32, partnerBitcoinPKH.length);
+		System.arraycopy(refundTimeoutBytes, 0, data, 56, refundTimeoutBytes.length);
+		System.arraycopy(hashOfSecretA, 0, data, 64, hashOfSecretA.length);
+		System.arraycopy(lockTimeABytes, 0, data, 88, lockTimeABytes.length);
+
+		return data;
+	}
+
+	/** Returns 'cancel' MESSAGE payload for AT creator to cancel trade AT. */
+	@Override
+	public byte[] buildCancelMessage(String creatorQortalAddress) {
+		byte[] data = new byte[CANCEL_MESSAGE_LENGTH];
+		byte[] creatorQortalAddressBytes = Base58.decode(creatorQortalAddress);
+
+		System.arraycopy(creatorQortalAddressBytes, 0, data, 0, creatorQortalAddressBytes.length);
+
+		return data;
+	}
+
+	/** Returns 'redeem' MESSAGE payload for trade partner to send to AT. */
+	public static byte[] buildRedeemMessage(byte[] secretA, String qortalReceivingAddress) {
+		byte[] data = new byte[REDEEM_MESSAGE_LENGTH];
+		byte[] qortalReceivingAddressBytes = Base58.decode(qortalReceivingAddress);
+
+		System.arraycopy(secretA, 0, data, 0, secretA.length);
+		System.arraycopy(qortalReceivingAddressBytes, 0, data, 32, qortalReceivingAddressBytes.length);
+
+		return data;
+	}
+
+	/** Returns refund timeout (minutes) based on trade partner's 'offer' MESSAGE timestamp and P2SH-A locktime. */
+	public static int calcRefundTimeout(long offerMessageTimestamp, int lockTimeA) {
+		// refund should be triggered halfway between offerMessageTimestamp and lockTimeA
+		return (int) ((lockTimeA - (offerMessageTimestamp / 1000L)) / 2L / 60L);
+	}
+
+	public static byte[] findSecretA(Repository repository, CrossChainTradeData crossChainTradeData) throws DataException {
+		String atAddress = crossChainTradeData.qortalAtAddress;
+		String redeemerAddress = crossChainTradeData.qortalPartnerAddress;
+
+		// We don't have partner's public key so we check every message to AT
+		List<MessageTransactionData> messageTransactionsData = repository.getMessageRepository().getMessagesByParticipants(null, atAddress, null, null, null);
+		if (messageTransactionsData == null)
+			return null;
+
+		// Find 'redeem' message
+		for (MessageTransactionData messageTransactionData : messageTransactionsData) {
+			// Check message payload type/encryption
+			if (messageTransactionData.isText() || messageTransactionData.isEncrypted())
+				continue;
+
+			// Check message payload size
+			byte[] messageData = messageTransactionData.getData();
+			if (messageData.length != REDEEM_MESSAGE_LENGTH)
+				// Wrong payload length
+				continue;
+
+			// Check sender
+			if (!Crypto.toAddress(messageTransactionData.getSenderPublicKey()).equals(redeemerAddress))
+				// Wrong sender;
+				continue;
+
+			// Extract secretA
+			byte[] secretA = new byte[32];
+			System.arraycopy(messageData, 0, secretA, 0, secretA.length);
+
+			byte[] hashOfSecretA = Crypto.hash160(secretA);
+			if (!Arrays.equals(hashOfSecretA, crossChainTradeData.hashOfSecretA))
+				continue;
+
+			return secretA;
+		}
+
+		return null;
+	}
+
+}

src/main/java/org/qortal/crosschain/SupportedBlockchain.java

@@ -0,0 +1,113 @@
+package org.qortal.crosschain;
+
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import java.util.function.Supplier;
+import java.util.stream.Collectors;
+
+import org.qortal.utils.ByteArray;
+import org.qortal.utils.Triple;
+
+public enum SupportedBlockchain {
+
+	BITCOIN(Arrays.asList(
+				Triple.valueOf(BitcoinACCTv1.NAME, BitcoinACCTv1.CODE_BYTES_HASH, BitcoinACCTv1::getInstance)
+				// Could add improved BitcoinACCTv2 here in the future
+			)) {
+		@Override
+		public ForeignBlockchain getInstance() {
+			return Bitcoin.getInstance();
+		}
+
+		@Override
+		public ACCT getLatestAcct() {
+			return BitcoinACCTv1.getInstance();
+		}
+	},
+
+	LITECOIN(Arrays.asList(
+			Triple.valueOf(LitecoinACCTv1.NAME, LitecoinACCTv1.CODE_BYTES_HASH, LitecoinACCTv1::getInstance)
+		)) {
+		@Override
+		public ForeignBlockchain getInstance() {
+			return Litecoin.getInstance();
+		}
+
+		@Override
+		public ACCT getLatestAcct() {
+			return LitecoinACCTv1.getInstance();
+		}
+	};
+
+	private static final Map<ByteArray, Supplier<ACCT>> supportedAcctsByCodeHash = Arrays.stream(SupportedBlockchain.values())
+			.map(supportedBlockchain -> supportedBlockchain.supportedAccts)
+			.flatMap(List::stream)
+			.collect(Collectors.toUnmodifiableMap(triple -> new ByteArray(triple.getB()), Triple::getC));
+
+	private static final Map<String, Supplier<ACCT>> supportedAcctsByName = Arrays.stream(SupportedBlockchain.values())
+			.map(supportedBlockchain -> supportedBlockchain.supportedAccts)
+			.flatMap(List::stream)
+			.collect(Collectors.toUnmodifiableMap(Triple::getA, Triple::getC));
+
+	private static final Map<String, SupportedBlockchain> blockchainsByName = Arrays.stream(SupportedBlockchain.values())
+			.collect(Collectors.toUnmodifiableMap(Enum::name, blockchain -> blockchain));
+
+	private final List<Triple<String, byte[], Supplier<ACCT>>> supportedAccts;
+
+	SupportedBlockchain(List<Triple<String, byte[], Supplier<ACCT>>> supportedAccts) {
+		this.supportedAccts = supportedAccts;
+	}
+
+	public abstract ForeignBlockchain getInstance();
+	public abstract ACCT getLatestAcct();
+
+	public static Map<ByteArray, Supplier<ACCT>> getAcctMap() {
+		return supportedAcctsByCodeHash;
+	}
+
+	public static SupportedBlockchain fromString(String name) {
+		return blockchainsByName.get(name);
+	}
+
+	public static Map<ByteArray, Supplier<ACCT>> getFilteredAcctMap(SupportedBlockchain blockchain) {
+		if (blockchain == null)
+			return getAcctMap();
+
+		return blockchain.supportedAccts.stream()
+				.collect(Collectors.toUnmodifiableMap(triple -> new ByteArray(triple.getB()), Triple::getC));
+	}
+
+	public static Map<ByteArray, Supplier<ACCT>> getFilteredAcctMap(String specificBlockchain) {
+		if (specificBlockchain == null)
+			return getAcctMap();
+
+		SupportedBlockchain blockchain = blockchainsByName.get(specificBlockchain);
+		if (blockchain == null)
+			return Collections.emptyMap();
+
+		return getFilteredAcctMap(blockchain);
+	}
+
+	public static ACCT getAcctByCodeHash(byte[] codeHash) {
+		ByteArray wrappedCodeHash = new ByteArray(codeHash);
+
+		Supplier<ACCT> acctInstanceSupplier = supportedAcctsByCodeHash.get(wrappedCodeHash);
+
+		if (acctInstanceSupplier == null)
+			return null;
+
+		return acctInstanceSupplier.get();
+	}
+
+	public static ACCT getAcctByName(String acctName) {
+		Supplier<ACCT> acctInstanceSupplier = supportedAcctsByName.get(acctName);
+
+		if (acctInstanceSupplier == null)
+			return null;
+
+		return acctInstanceSupplier.get();
+	}
+
+}

src/main/java/org/qortal/data/crosschain/CrossChainTradeData.java

@@ -4,7 +4,7 @@ import javax.xml.bind.annotation.XmlAccessType;
 import javax.xml.bind.annotation.XmlAccessorType;
 import javax.xml.bind.annotation.adapters.XmlJavaTypeAdapter;
 
-import org.qortal.crosschain.BTCACCT;
+import org.qortal.crosschain.AcctMode;
 
 import io.swagger.v3.oas.annotations.media.Schema;
 
@@ -20,12 +20,16 @@ public class CrossChainTradeData {
 	@Schema(description = "AT creator's Qortal address")
 	public String qortalCreator;
 
-	@Schema(description = "AT creator's Qortal trade address")
+	@Schema(description = "AT creator's ephemeral trading key-pair represented as Qortal address")
 	public String qortalCreatorTradeAddress;
 
-	@Schema(description = "AT creator's Bitcoin trade public-key-hash (PKH)")
+	@Deprecated
+	@Schema(description = "DEPRECATED: use creatorForeignPKH instead")
 	public byte[] creatorBitcoinPKH;
 
+	@Schema(description = "AT creator's foreign blockchain trade public-key-hash (PKH)")
+	public byte[] creatorForeignPKH;
+
 	@Schema(description = "Timestamp when AT was created (milliseconds since epoch)")
 	public long creationTimestamp;
 
@@ -58,28 +62,48 @@ public class CrossChainTradeData {
 	@Schema(description = "Actual Qortal block height when AT will automatically refund to AT creator (after trade begins)")
 	public Integer tradeRefundHeight;
 
-	@Schema(description = "Amount, in BTC, that AT creator expects Bitcoin P2SH to pay out (excluding miner fees)")
+	@Deprecated
+	@Schema(description = "DEPRECATED: use expectedForeignAmount instread")
 	@XmlJavaTypeAdapter(value = org.qortal.api.AmountTypeAdapter.class)
 	public long expectedBitcoin;
 
-	public BTCACCT.Mode mode;
+	@Schema(description = "Amount, in foreign blockchain currency, that AT creator expects trade partner to pay out (excluding miner fees)")
+	@XmlJavaTypeAdapter(value = org.qortal.api.AmountTypeAdapter.class)
+	public long expectedForeignAmount;
 
-	@Schema(description = "Suggested Bitcoin P2SH-A nLockTime based on trade timeout")
+	@Schema(description = "Current AT execution mode")
+	public AcctMode mode;
+
+	@Schema(description = "Suggested P2SH-A nLockTime based on trade timeout")
 	public Integer lockTimeA;
 
-	@Schema(description = "Suggested Bitcoin P2SH-B nLockTime based on trade timeout")
+	@Schema(description = "Suggested P2SH-B nLockTime based on trade timeout")
 	public Integer lockTimeB;
 
-	@Schema(description = "Trade partner's Bitcoin public-key-hash (PKH)")
+	@Deprecated
+	@Schema(description = "DEPRECATED: use partnerForeignPKH instead")
 	public byte[] partnerBitcoinPKH;
 
+	@Schema(description = "Trade partner's foreign blockchain public-key-hash (PKH)")
+	public byte[] partnerForeignPKH;
+
 	@Schema(description = "Trade partner's Qortal receiving address")
 	public String qortalPartnerReceivingAddress;
 
+	public String foreignBlockchain;
+
+	public String acctName;
+
 	// Constructors
 
 	// Necessary for JAXB
 	public CrossChainTradeData() {
 	}
 
+	public void duplicateDeprecated() {
+		this.creatorBitcoinPKH = this.creatorForeignPKH;
+		this.expectedBitcoin = this.expectedForeignAmount;
+		this.partnerBitcoinPKH = this.partnerForeignPKH;
+	}
+
 }

src/main/java/org/qortal/data/crosschain/TradeBotData.java

@@ -1,10 +1,5 @@
 package org.qortal.data.crosschain;
 
-import static java.util.Arrays.stream;
-import static java.util.stream.Collectors.toMap;
-
-import java.util.Map;
-
 import javax.xml.bind.annotation.XmlAccessType;
 import javax.xml.bind.annotation.XmlAccessorType;
 import javax.xml.bind.annotation.XmlTransient;
@@ -18,22 +13,13 @@ public class TradeBotData {
 
 	private byte[] tradePrivateKey;
 
-	public enum State {
-		BOB_WAITING_FOR_AT_CONFIRM(10), BOB_WAITING_FOR_MESSAGE(15), BOB_WAITING_FOR_P2SH_B(20), BOB_WAITING_FOR_AT_REDEEM(25), BOB_DONE(30), BOB_REFUNDED(35),
-		ALICE_WAITING_FOR_P2SH_A(80), ALICE_WAITING_FOR_AT_LOCK(85), ALICE_WATCH_P2SH_B(90), ALICE_DONE(95), ALICE_REFUNDING_B(100), ALICE_REFUNDING_A(105), ALICE_REFUNDED(110);
+	private String acctName;
+	private String tradeState;
 
-		public final int value;
-		private static final Map<Integer, State> map = stream(State.values()).collect(toMap(state -> state.value, state -> state));
-
-		State(int value) {
-			this.value = value;
-		}
-
-		public static State valueOf(int value) {
-			return map.get(value);
-		}
-	}
-	private State tradeState;
+	// Internal use - not shown via API
+	@XmlTransient
+	@Schema(hidden = true)
+	private int tradeStateValue;
 
 	private String creatorAddress;
 	private String atAddress;
@@ -50,19 +36,25 @@ public class TradeBotData {
 	private byte[] secret;
 	private byte[] hashOfSecret;
 
+	private String foreignBlockchain;
 	private byte[] tradeForeignPublicKey;
 	private byte[] tradeForeignPublicKeyHash;
 
+	@Deprecated
+	@Schema(description = "DEPRECATED: use foreignAmount instead", type = "number")
 	@XmlJavaTypeAdapter(value = org.qortal.api.AmountTypeAdapter.class)
 	private long bitcoinAmount;
 
+	@Schema(description = "amount in foreign blockchain currency", type = "number")
+	@XmlJavaTypeAdapter(value = org.qortal.api.AmountTypeAdapter.class)
+	private long foreignAmount;
+
 	// Never expose this via API
 	@XmlTransient
 	@Schema(hidden = true)
-	private String xprv58;
+	private String foreignKey;
 
 	private byte[] lastTransactionSignature;
-
 	private Integer lockTimeA;
 
 	// Could be Bitcoin or Qortal...
@@ -72,14 +64,18 @@ public class TradeBotData {
 		/* JAXB */
 	}
 
-	public TradeBotData(byte[] tradePrivateKey, State tradeState, String creatorAddress, String atAddress,
+	public TradeBotData(byte[] tradePrivateKey, String acctName, String tradeState, int tradeStateValue,
+			String creatorAddress, String atAddress,
 			long timestamp, long qortAmount,
 			byte[] tradeNativePublicKey, byte[] tradeNativePublicKeyHash, String tradeNativeAddress,
 			byte[] secret, byte[] hashOfSecret,
-			byte[] tradeForeignPublicKey, byte[] tradeForeignPublicKeyHash,
-			long bitcoinAmount, String xprv58, byte[] lastTransactionSignature, Integer lockTimeA, byte[] receivingAccountInfo) {
+			String foreignBlockchain, byte[] tradeForeignPublicKey, byte[] tradeForeignPublicKeyHash,
+			long foreignAmount, String foreignKey,
+			byte[] lastTransactionSignature, Integer lockTimeA, byte[] receivingAccountInfo) {
 		this.tradePrivateKey = tradePrivateKey;
+		this.acctName = acctName;
 		this.tradeState = tradeState;
+		this.tradeStateValue = tradeStateValue;
 		this.creatorAddress = creatorAddress;
 		this.atAddress = atAddress;
 		this.timestamp = timestamp;
@@ -89,10 +85,13 @@ public class TradeBotData {
 		this.tradeNativeAddress = tradeNativeAddress;
 		this.secret = secret;
 		this.hashOfSecret = hashOfSecret;
+		this.foreignBlockchain = foreignBlockchain;
 		this.tradeForeignPublicKey = tradeForeignPublicKey;
 		this.tradeForeignPublicKeyHash = tradeForeignPublicKeyHash;
-		this.bitcoinAmount = bitcoinAmount;
-		this.xprv58 = xprv58;
+		// deprecated copy
+		this.bitcoinAmount = foreignAmount;
+		this.foreignAmount = foreignAmount;
+		this.foreignKey = foreignKey;
 		this.lastTransactionSignature = lastTransactionSignature;
 		this.lockTimeA = lockTimeA;
 		this.receivingAccountInfo = receivingAccountInfo;
@@ -102,14 +101,26 @@ public class TradeBotData {
 		return this.tradePrivateKey;
 	}
 
-	public State getState() {
+	public String getAcctName() {
+		return this.acctName;
+	}
+
+	public String getState() {
 		return this.tradeState;
 	}
 
-	public void setState(State state) {
+	public void setState(String state) {
 		this.tradeState = state;
 	}
 
+	public int getStateValue() {
+		return this.tradeStateValue;
+	}
+
+	public void setStateValue(int stateValue) {
+		this.tradeStateValue = stateValue;
+	}
+
 	public String getCreatorAddress() {
 		return this.creatorAddress;
 	}
@@ -154,6 +165,10 @@ public class TradeBotData {
 		return this.hashOfSecret;
 	}
 
+	public String getForeignBlockchain() {
+		return this.foreignBlockchain;
+	}
+
 	public byte[] getTradeForeignPublicKey() {
 		return this.tradeForeignPublicKey;
 	}
@@ -162,12 +177,12 @@ public class TradeBotData {
 		return this.tradeForeignPublicKeyHash;
 	}
 
-	public long getBitcoinAmount() {
-		return this.bitcoinAmount;
+	public long getForeignAmount() {
+		return this.foreignAmount;
 	}
 
-	public String getXprv58() {
-		return this.xprv58;
+	public String getForeignKey() {
+		return this.foreignKey;
 	}
 
 	public byte[] getLastTransactionSignature() {
@@ -192,7 +207,7 @@ public class TradeBotData {
 
 	// Mostly for debugging
 	public String toString() {
-		return String.format("%s: %s", this.atAddress, this.tradeState.name());
+		return String.format("%s: %s (%d)", this.atAddress, this.tradeState, this.tradeStateValue);
 	}
 
 }

src/main/java/org/qortal/data/transaction/PresenceTransactionData.java

@@ -0,0 +1,73 @@
+package org.qortal.data.transaction;
+
+import javax.xml.bind.Unmarshaller;
+import javax.xml.bind.annotation.XmlAccessType;
+import javax.xml.bind.annotation.XmlAccessorType;
+
+import org.qortal.transaction.PresenceTransaction.PresenceType;
+import org.qortal.transaction.Transaction.TransactionType;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+import io.swagger.v3.oas.annotations.media.Schema.AccessMode;
+
+// All properties to be converted to JSON via JAXB
+@XmlAccessorType(XmlAccessType.FIELD)
+@Schema(allOf = { TransactionData.class })
+public class PresenceTransactionData extends TransactionData {
+
+	// Properties
+	@Schema(description = "sender's public key", example = "2tiMr5LTpaWCgbRvkPK8TFd7k63DyHJMMFFsz9uBf1ZP")
+	private byte[] senderPublicKey;
+
+	@Schema(accessMode = AccessMode.READ_ONLY)
+	private int nonce;
+
+	private PresenceType presenceType;
+
+	@Schema(description = "timestamp signature", example = "2yGEbwRFyhPZZckKA")
+	private byte[] timestampSignature;
+
+	// Constructors
+
+	// For JAXB
+	protected PresenceTransactionData() {
+		super(TransactionType.PRESENCE);
+	}
+
+	public void afterUnmarshal(Unmarshaller u, Object parent) {
+		this.creatorPublicKey = this.senderPublicKey;
+	}
+
+	public PresenceTransactionData(BaseTransactionData baseTransactionData,
+			int nonce, PresenceType presenceType, byte[] timestampSignature) {
+		super(TransactionType.PRESENCE, baseTransactionData);
+
+		this.senderPublicKey = baseTransactionData.creatorPublicKey;
+		this.nonce = nonce;
+		this.presenceType = presenceType;
+		this.timestampSignature = timestampSignature;
+	}
+
+	// Getters/Setters
+
+	public byte[] getSenderPublicKey() {
+		return this.senderPublicKey;
+	}
+
+	public int getNonce() {
+		return this.nonce;
+	}
+
+	public void setNonce(int nonce) {
+		this.nonce = nonce;
+	}
+
+	public PresenceType getPresenceType() {
+		return this.presenceType;
+	}
+
+	public byte[] getTimestampSignature() {
+		return this.timestampSignature;
+	}
+
+}

src/main/java/org/qortal/data/transaction/TransactionData.java

@@ -40,7 +40,7 @@ import io.swagger.v3.oas.annotations.media.Schema.AccessMode;
 	GroupApprovalTransactionData.class, SetGroupTransactionData.class,
 	UpdateAssetTransactionData.class,
 	AccountFlagsTransactionData.class, RewardShareTransactionData.class,
-	AccountLevelTransactionData.class, ChatTransactionData.class
+	AccountLevelTransactionData.class, ChatTransactionData.class, PresenceTransactionData.class
 })
 //All properties to be converted to JSON via JAXB
 @XmlAccessorType(XmlAccessType.FIELD)

src/main/java/org/qortal/event/EventBus.java

@@ -3,9 +3,14 @@ package org.qortal.event;
 import java.util.ArrayList;
 import java.util.List;
 
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
 public enum EventBus {
 	INSTANCE;
 
+	private static final Logger LOGGER = LogManager.getLogger(EventBus.class);
+
 	private static final List<Listener> LISTENERS = new ArrayList<>();
 
 	public void addListener(Listener newListener) {
@@ -22,18 +27,25 @@ public enum EventBus {
 
 	/**
 	 * <b>WARNING:</b> before calling this method,
-	 * make sure repository holds no locks, e.g. by calling
+	 * make sure current thread's repository session
+	 * holds no locks, e.g. by calling
+	 * <tt>repository.saveChanges()</tt> or
 	 * <tt>repository.discardChanges()</tt>.
 	 * <p>
 	 * This is because event listeners might open a new
 	 * repository session which will deadlock HSQLDB
 	 * if it tries to CHECKPOINT.
 	 * <p>
-	 * The HSQLDB deadlock occurs because the caller's
-	 * repository session blocks the CHECKPOINT until
-	 * their transaction is closed, yet event listeners
-	 * new sessions are blocked until CHECKPOINT is
-	 * completed, hence deadlock.
+	 * The HSQLDB deadlock path is:
+	 * <ul>
+	 * <li>write-log <tt>blockchain.log</tt> has grown past CHECKPOINT threshold (50MB)</li>
+	 * <li>alternatively, another thread has explicitly requested CHECKPOINT</li>
+	 * <li>HSQLDB won't begin CHECKPOINT until all pending (SQL) transactions are committed or rolled back</li>
+	 * <li>Same thread calls <tt>EventBus.INSTANCE.notify()</tt> <i>before</i> (SQL) transaction closed</li>
+	 * <li>EventBus listener (same thread) requests a new repository session via <tt>RepositoryManager.getRepository()</tt></li>
+	 * <li>New repository sessions are blocked pending completion of CHECKPOINT</li>
+	 * <li>Caller is blocked so never has a chance to close (SQL) transaction - hence deadlock</li>
+	 * </ul>
 	 */
 	public void notify(Event event) {
 		List<Listener> clonedListeners;
@@ -43,6 +55,11 @@ public enum EventBus {
 		}
 
 		for (Listener listener : clonedListeners)
-			listener.listen(event);
+			try {
+				listener.listen(event);
+			} catch (Exception e) {
+				// We don't want one listener to break other listeners, or caller
+				LOGGER.warn(() -> String.format("Caught %s from a listener processing %s", e.getClass().getSimpleName(), event.getClass().getSimpleName()), e);
+			}
 	}
 }

src/main/java/org/qortal/repository/ATRepository.java

@@ -1,9 +1,11 @@
 package org.qortal.repository;
 
 import java.util.List;
+import java.util.Set;
 
 import org.qortal.data.at.ATData;
 import org.qortal.data.at.ATStateData;
+import org.qortal.utils.ByteArray;
 
 public interface ATRepository {
 
@@ -24,6 +26,9 @@ public interface ATRepository {
 	/** Returns list of ATs with matching code hash, optionally executable only. */
 	public List<ATData> getATsByFunctionality(byte[] codeHash, Boolean isExecutable, Integer limit, Integer offset, Boolean reverse) throws DataException;
 
+	/** Returns list of all ATs matching one of passed code hashes, optionally executable only. */
+	public List<ATData> getAllATsByFunctionality(Set<ByteArray> codeHashes, Boolean isExecutable) throws DataException;
+
 	/** Returns creation block height given AT's address or null if not found */
 	public Integer getATCreationBlockHeight(String atAddress) throws DataException;
 
@@ -75,6 +80,26 @@ public interface ATRepository {
 			Integer dataByteOffset, Long expectedValue, Integer minimumFinalHeight,
 			Integer limit, Integer offset, Boolean reverse) throws DataException;
 
+	/**
+	 * Returns final ATStateData for ATs matching codeHash (required)
+	 * and specific data segment value (optional), returning at least
+	 * <tt>minimumCount</tt> entries over a span of at least
+	 * <tt>minimumPeriod</tt> ms, given enough entries in repository.
+	 * <p>
+	 * If searching for specific data segment value, both <tt>dataByteOffset</tt>
+	 * and <tt>expectedValue</tt> need to be non-null.
+	 * <p>
+	 * Note that <tt>dataByteOffset</tt> starts from 0 and will typically be
+	 * a multiple of <tt>MachineState.VALUE_SIZE</tt>, which is usually 8:
+	 * width of a long.
+	 * <p>
+	 * Although <tt>expectedValue</tt>, if provided, is natively an unsigned long,
+	 * the data segment comparison is done via unsigned hex string.
+	 */
+	public List<ATStateData> getMatchingFinalATStatesQuorum(byte[] codeHash, Boolean isFinished,
+			Integer dataByteOffset, Long expectedValue,
+			int minimumCount, long minimumPeriod) throws DataException;
+
 	/**
 	 * Returns all ATStateData for a given block height.
 	 * <p>

src/main/java/org/qortal/repository/CrossChainRepository.java

@@ -8,6 +8,9 @@ public interface CrossChainRepository {
 
 	public TradeBotData getTradeBotData(byte[] tradePrivateKey) throws DataException;
 
+	/** Returns true if there is an existing trade-bot entry relating to given AT address, excluding trade-bot entries with given states. */
+	public boolean existsTradeWithAtExcludingStates(String atAddress, List<String> excludeStates) throws DataException;
+
 	public List<TradeBotData> getAllTradeBotData() throws DataException;
 
 	public void save(TradeBotData tradeBotData) throws DataException;

src/main/java/org/qortal/repository/TransactionRepository.java

@@ -239,6 +239,18 @@ public interface TransactionRepository {
 		return getUnconfirmedTransactions(null, null, null);
 	}
 
+	/**
+	 * Returns list of unconfirmed transactions with specified type and/or creator.
+	 * <p>
+	 * At least one of <tt>txType</tt> or <tt>creatorPublicKey</tt> must be non-null.
+	 * 
+	 * @param txType optional
+	 * @param creatorPublicKey optional
+	 * @return list of transactions, or empty if none.
+	 * @throws DataException
+	 */
+	public List<TransactionData> getUnconfirmedTransactions(TransactionType txType, byte[] creatorPublicKey) throws DataException;
+
 	/**
 	 * Remove transaction from unconfirmed transactions pile.
 	 * 

src/main/java/org/qortal/repository/hsqldb/HSQLDBATRepository.java

@@ -4,6 +4,7 @@ import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Set;
 
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
@@ -11,6 +12,7 @@ import org.qortal.data.at.ATData;
 import org.qortal.data.at.ATStateData;
 import org.qortal.repository.ATRepository;
 import org.qortal.repository.DataException;
+import org.qortal.utils.ByteArray;
 
 import com.google.common.primitives.Longs;
 
@@ -201,6 +203,80 @@ public class HSQLDBATRepository implements ATRepository {
 		}
 	}
 
+	@Override
+	public List<ATData> getAllATsByFunctionality(Set<ByteArray> codeHashes, Boolean isExecutable) throws DataException {
+		StringBuilder sql = new StringBuilder(512);
+		List<Object> bindParams = new ArrayList<>();
+
+		sql.append("SELECT AT_address, creator, created_when, version, asset_id, code_bytes, ")
+				.append("is_sleeping, sleep_until_height, is_finished, had_fatal_error, ")
+				.append("is_frozen, frozen_balance, code_hash ")
+				.append("FROM ");
+
+		// (VALUES (?), (?), ...) AS ATCodeHashes (code_hash)
+		sql.append("(VALUES ");
+
+		boolean isFirst = true;
+		for (ByteArray codeHash : codeHashes) {
+			if (!isFirst)
+				sql.append(", ");
+			else
+				isFirst = false;
+
+			sql.append("(CAST(? AS VARBINARY(256)))");
+			bindParams.add(codeHash.value);
+		}
+		sql.append(") AS ATCodeHashes (code_hash) ");
+
+		sql.append("JOIN ATs ON ATs.code_hash = ATCodeHashes.code_hash ");
+
+		if (isExecutable != null) {
+			sql.append("AND is_finished != ? ");
+			bindParams.add(isExecutable);
+		}
+
+		List<ATData> matchingATs = new ArrayList<>();
+
+		try (ResultSet resultSet = this.repository.checkedExecute(sql.toString(), bindParams.toArray())) {
+			if (resultSet == null)
+				return matchingATs;
+
+			do {
+				String atAddress = resultSet.getString(1);
+				byte[] creatorPublicKey = resultSet.getBytes(2);
+				long created = resultSet.getLong(3);
+				int version = resultSet.getInt(4);
+				long assetId = resultSet.getLong(5);
+				byte[] codeBytes = resultSet.getBytes(6); // Actually BLOB
+				boolean isSleeping = resultSet.getBoolean(7);
+
+				Integer sleepUntilHeight = resultSet.getInt(8);
+				if (sleepUntilHeight == 0 && resultSet.wasNull())
+					sleepUntilHeight = null;
+
+				boolean isFinished = resultSet.getBoolean(9);
+
+				boolean hadFatalError = resultSet.getBoolean(10);
+				boolean isFrozen = resultSet.getBoolean(11);
+
+				Long frozenBalance = resultSet.getLong(12);
+				if (frozenBalance == 0 && resultSet.wasNull())
+					frozenBalance = null;
+
+				byte[] codeHash = resultSet.getBytes(13);
+
+				ATData atData = new ATData(atAddress, creatorPublicKey, created, version, assetId, codeBytes, codeHash,
+						isSleeping, sleepUntilHeight, isFinished, hadFatalError, isFrozen, frozenBalance);
+
+				matchingATs.add(atData);
+			} while (resultSet.next());
+
+			return matchingATs;
+		} catch (SQLException e) {
+			throw new DataException("Unable to fetch matching ATs from repository", e);
+		}
+	}
+
 	@Override
 	public Integer getATCreationBlockHeight(String atAddress) throws DataException {
 		String sql = "SELECT height "
@@ -375,6 +451,92 @@ public class HSQLDBATRepository implements ATRepository {
 		}
 	}
 
+	@Override
+	public List<ATStateData> getMatchingFinalATStatesQuorum(byte[] codeHash, Boolean isFinished,
+			Integer dataByteOffset, Long expectedValue,
+			int minimumCount, long minimumPeriod) throws DataException {
+		// We need most recent entry first so we can use its timestamp to slice further results
+		List<ATStateData> mostRecentStates = this.getMatchingFinalATStates(codeHash, isFinished,
+				dataByteOffset, expectedValue, null,
+				1, 0, true);
+
+		if (mostRecentStates == null)
+			return null;
+
+		if (mostRecentStates.isEmpty())
+			return mostRecentStates;
+
+		ATStateData mostRecentState = mostRecentStates.get(0);
+
+		StringBuilder sql = new StringBuilder(1024);
+		List<Object> bindParams = new ArrayList<>();
+
+		sql.append("SELECT AT_address, height, state_data, state_hash, fees, is_initial "
+				+ "FROM ATs "
+				+ "CROSS JOIN LATERAL("
+					+ "SELECT height, state_data, state_hash, fees, is_initial "
+					+ "FROM ATStates "
+					+ "JOIN ATStatesData USING (AT_address, height) "
+					+ "WHERE ATStates.AT_address = ATs.AT_address ");
+
+		// Order by AT_address and height to use compound primary key as index
+		// Both must be the same direction (DESC) also
+		sql.append("ORDER BY ATStates.AT_address DESC, ATStates.height DESC "
+					+ "LIMIT 1 "
+				+ ") AS FinalATStates "
+				+ "WHERE code_hash = ? ");
+		bindParams.add(codeHash);
+
+		if (isFinished != null) {
+			sql.append("AND is_finished = ? ");
+			bindParams.add(isFinished);
+		}
+
+		if (dataByteOffset != null && expectedValue != null) {
+			sql.append("AND SUBSTRING(state_data FROM ? FOR 8) = ? ");
+
+			// We convert our long on Java-side to control endian
+			byte[] rawExpectedValue = Longs.toByteArray(expectedValue);
+
+			// SQL binary data offsets start at 1
+			bindParams.add(dataByteOffset + 1);
+			bindParams.add(rawExpectedValue);
+		}
+
+		// Slice so that we meet both minimumCount and minimumPeriod
+		int minimumHeight = mostRecentState.getHeight() - (int) (minimumPeriod / 60 * 1000L); // XXX assumes 60 second blocks
+
+		sql.append("AND (FinalATStates.height >= ? OR ROWNUM() < ?) ");
+		bindParams.add(minimumHeight);
+		bindParams.add(minimumCount);
+
+		sql.append("ORDER BY FinalATStates.height DESC");
+
+		List<ATStateData> atStates = new ArrayList<>();
+
+		try (ResultSet resultSet = this.repository.checkedExecute(sql.toString(), bindParams.toArray())) {
+			if (resultSet == null)
+				return atStates;
+
+			do {
+				String atAddress = resultSet.getString(1);
+				int height = resultSet.getInt(2);
+				byte[] stateData = resultSet.getBytes(3); // Actually BLOB
+				byte[] stateHash = resultSet.getBytes(4);
+				long fees = resultSet.getLong(5);
+				boolean isInitial = resultSet.getBoolean(6);
+
+				ATStateData atStateData = new ATStateData(atAddress, height, stateData, stateHash, fees, isInitial);
+
+				atStates.add(atStateData);
+			} while (resultSet.next());
+
+			return atStates;
+		} catch (SQLException e) {
+			throw new DataException("Unable to fetch matching AT states from repository", e);
+		}
+	}
+
 	@Override
 	public List<ATStateData> getBlockATStatesAtHeight(int height) throws DataException {
 		String sql = "SELECT AT_address, state_hash, fees, is_initial "

src/main/java/org/qortal/repository/hsqldb/HSQLDBCrossChainRepository.java

@@ -3,6 +3,7 @@ package org.qortal.repository.hsqldb;
 import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 
 import org.qortal.data.crosschain.TradeBotData;
@@ -19,12 +20,13 @@ public class HSQLDBCrossChainRepository implements CrossChainRepository {
 
 	@Override
 	public TradeBotData getTradeBotData(byte[] tradePrivateKey) throws DataException {
-		String sql = "SELECT trade_state, creator_address, at_address, "
+		String sql = "SELECT acct_name, trade_state, trade_state_value, "
+				+ "creator_address, at_address, "
 				+ "updated_when, qort_amount, "
 				+ "trade_native_public_key, trade_native_public_key_hash, "
 				+ "trade_native_address, secret, hash_of_secret, "
-				+ "trade_foreign_public_key, trade_foreign_public_key_hash, "
-				+ "bitcoin_amount, xprv58, last_transaction_signature, locktime_a, receiving_account_info "
+				+ "foreign_blockchain, trade_foreign_public_key, trade_foreign_public_key_hash, "
+				+ "foreign_amount, foreign_key, last_transaction_signature, locktime_a, receiving_account_info "
 				+ "FROM TradeBotStates "
 				+ "WHERE trade_private_key = ?";
 
@@ -32,49 +34,80 @@ public class HSQLDBCrossChainRepository implements CrossChainRepository {
 			if (resultSet == null)
 				return null;
 
-			int tradeStateValue = resultSet.getInt(1);
-			TradeBotData.State tradeState = TradeBotData.State.valueOf(tradeStateValue);
-			if (tradeState == null)
-				throw new DataException("Illegal trade-bot trade-state fetched from repository");
-
-			String creatorAddress = resultSet.getString(2);
-			String atAddress = resultSet.getString(3);
-			long timestamp = resultSet.getLong(4);
-			long qortAmount = resultSet.getLong(5);
-			byte[] tradeNativePublicKey = resultSet.getBytes(6);
-			byte[] tradeNativePublicKeyHash = resultSet.getBytes(7);
-			String tradeNativeAddress = resultSet.getString(8);
-			byte[] secret = resultSet.getBytes(9);
-			byte[] hashOfSecret = resultSet.getBytes(10);
-			byte[] tradeForeignPublicKey = resultSet.getBytes(11);
-			byte[] tradeForeignPublicKeyHash = resultSet.getBytes(12);
-			long bitcoinAmount = resultSet.getLong(13);
-			String xprv58 = resultSet.getString(14);
-			byte[] lastTransactionSignature = resultSet.getBytes(15);
-			Integer lockTimeA = resultSet.getInt(16);
+			String acctName = resultSet.getString(1);
+			String tradeState = resultSet.getString(2);
+			int tradeStateValue = resultSet.getInt(3);
+			String creatorAddress = resultSet.getString(4);
+			String atAddress = resultSet.getString(5);
+			long timestamp = resultSet.getLong(6);
+			long qortAmount = resultSet.getLong(7);
+			byte[] tradeNativePublicKey = resultSet.getBytes(8);
+			byte[] tradeNativePublicKeyHash = resultSet.getBytes(9);
+			String tradeNativeAddress = resultSet.getString(10);
+			byte[] secret = resultSet.getBytes(11);
+			byte[] hashOfSecret = resultSet.getBytes(12);
+			String foreignBlockchain = resultSet.getString(13);
+			byte[] tradeForeignPublicKey = resultSet.getBytes(14);
+			byte[] tradeForeignPublicKeyHash = resultSet.getBytes(15);
+			long foreignAmount = resultSet.getLong(16);
+			String foreignKey = resultSet.getString(17);
+			byte[] lastTransactionSignature = resultSet.getBytes(18);
+			Integer lockTimeA = resultSet.getInt(19);
 			if (lockTimeA == 0 && resultSet.wasNull())
 				lockTimeA = null;
-			byte[] receivingAccountInfo = resultSet.getBytes(17);
+			byte[] receivingAccountInfo = resultSet.getBytes(20);
 
-			return new TradeBotData(tradePrivateKey, tradeState,
+			return new TradeBotData(tradePrivateKey, acctName,
+					tradeState, tradeStateValue,
 					creatorAddress, atAddress, timestamp, qortAmount,
 					tradeNativePublicKey, tradeNativePublicKeyHash, tradeNativeAddress,
 					secret, hashOfSecret,
-					tradeForeignPublicKey, tradeForeignPublicKeyHash,
-					bitcoinAmount, xprv58, lastTransactionSignature, lockTimeA, receivingAccountInfo);
+					foreignBlockchain, tradeForeignPublicKey, tradeForeignPublicKeyHash,
+					foreignAmount, foreignKey, lastTransactionSignature, lockTimeA, receivingAccountInfo);
 		} catch (SQLException e) {
 			throw new DataException("Unable to fetch trade-bot trading state from repository", e);
 		}
 	}
 
+	@Override
+	public boolean existsTradeWithAtExcludingStates(String atAddress, List<String> excludeStates) throws DataException {
+		if (excludeStates == null)
+			excludeStates = Collections.emptyList();
+
+		StringBuilder whereClause = new StringBuilder(256);
+		whereClause.append("at_address = ?");
+
+		Object[] bindParams = new Object[1 + excludeStates.size()];
+		bindParams[0] = atAddress;
+
+		if (!excludeStates.isEmpty()) {
+			whereClause.append(" AND trade_state NOT IN (?");
+			bindParams[1] = excludeStates.get(0);
+
+			for (int i = 1; i < excludeStates.size(); ++i) {
+				whereClause.append(", ?");
+				bindParams[1 + i] = excludeStates.get(i);
+			}
+
+			whereClause.append(")");
+		}
+
+		try {
+			return this.repository.exists("TradeBotStates", whereClause.toString(), bindParams);
+		} catch (SQLException e) {
+			throw new DataException("Unable to check for trade-bot state in repository", e);
+		}
+	}
+
 	@Override
 	public List<TradeBotData> getAllTradeBotData() throws DataException {
-		String sql = "SELECT trade_private_key, trade_state, creator_address, at_address, "
+		String sql = "SELECT trade_private_key, acct_name, trade_state, trade_state_value, "
+				+ "creator_address, at_address, "
 				+ "updated_when, qort_amount, "
 				+ "trade_native_public_key, trade_native_public_key_hash, "
 				+ "trade_native_address, secret, hash_of_secret, "
-				+ "trade_foreign_public_key, trade_foreign_public_key_hash, "
-				+ "bitcoin_amount, xprv58, last_transaction_signature, locktime_a, receiving_account_info "
+				+ "foreign_blockchain, trade_foreign_public_key, trade_foreign_public_key_hash, "
+				+ "foreign_amount, foreign_key, last_transaction_signature, locktime_a, receiving_account_info "
 				+ "FROM TradeBotStates";
 
 		List<TradeBotData> allTradeBotData = new ArrayList<>();
@@ -85,36 +118,36 @@ public class HSQLDBCrossChainRepository implements CrossChainRepository {
 
 			do {
 				byte[] tradePrivateKey = resultSet.getBytes(1);
-				int tradeStateValue = resultSet.getInt(2);
-				TradeBotData.State tradeState = TradeBotData.State.valueOf(tradeStateValue);
-				if (tradeState == null)
-					throw new DataException("Illegal trade-bot trade-state fetched from repository");
-
-				String creatorAddress = resultSet.getString(3);
-				String atAddress = resultSet.getString(4);
-				long timestamp = resultSet.getLong(5);
-				long qortAmount = resultSet.getLong(6);
-				byte[] tradeNativePublicKey = resultSet.getBytes(7);
-				byte[] tradeNativePublicKeyHash = resultSet.getBytes(8);
-				String tradeNativeAddress = resultSet.getString(9);
-				byte[] secret = resultSet.getBytes(10);
-				byte[] hashOfSecret = resultSet.getBytes(11);
-				byte[] tradeForeignPublicKey = resultSet.getBytes(12);
-				byte[] tradeForeignPublicKeyHash = resultSet.getBytes(13);
-				long bitcoinAmount = resultSet.getLong(14);
-				String xprv58 = resultSet.getString(15);
-				byte[] lastTransactionSignature = resultSet.getBytes(16);
-				Integer lockTimeA = resultSet.getInt(17);
+				String acctName = resultSet.getString(2);
+				String tradeState = resultSet.getString(3);
+				int tradeStateValue = resultSet.getInt(4);
+				String creatorAddress = resultSet.getString(5);
+				String atAddress = resultSet.getString(6);
+				long timestamp = resultSet.getLong(7);
+				long qortAmount = resultSet.getLong(8);
+				byte[] tradeNativePublicKey = resultSet.getBytes(9);
+				byte[] tradeNativePublicKeyHash = resultSet.getBytes(10);
+				String tradeNativeAddress = resultSet.getString(11);
+				byte[] secret = resultSet.getBytes(12);
+				byte[] hashOfSecret = resultSet.getBytes(13);
+				String foreignBlockchain = resultSet.getString(14);
+				byte[] tradeForeignPublicKey = resultSet.getBytes(15);
+				byte[] tradeForeignPublicKeyHash = resultSet.getBytes(16);
+				long foreignAmount = resultSet.getLong(17);
+				String foreignKey = resultSet.getString(18);
+				byte[] lastTransactionSignature = resultSet.getBytes(19);
+				Integer lockTimeA = resultSet.getInt(20);
 				if (lockTimeA == 0 && resultSet.wasNull())
 					lockTimeA = null;
-				byte[] receivingAccountInfo = resultSet.getBytes(18);
+				byte[] receivingAccountInfo = resultSet.getBytes(21);
 
-				TradeBotData tradeBotData = new TradeBotData(tradePrivateKey, tradeState,
+				TradeBotData tradeBotData = new TradeBotData(tradePrivateKey, acctName,
+						tradeState, tradeStateValue,
 						creatorAddress, atAddress, timestamp, qortAmount,
 						tradeNativePublicKey, tradeNativePublicKeyHash, tradeNativeAddress,
 						secret, hashOfSecret,
-						tradeForeignPublicKey, tradeForeignPublicKeyHash,
-						bitcoinAmount, xprv58, lastTransactionSignature, lockTimeA, receivingAccountInfo);
+						foreignBlockchain, tradeForeignPublicKey, tradeForeignPublicKeyHash,
+						foreignAmount, foreignKey, lastTransactionSignature, lockTimeA, receivingAccountInfo);
 				allTradeBotData.add(tradeBotData);
 			} while (resultSet.next());
 
@@ -129,7 +162,9 @@ public class HSQLDBCrossChainRepository implements CrossChainRepository {
 		HSQLDBSaver saveHelper = new HSQLDBSaver("TradeBotStates");
 
 		saveHelper.bind("trade_private_key", tradeBotData.getTradePrivateKey())
-				.bind("trade_state", tradeBotData.getState().value)
+				.bind("acct_name", tradeBotData.getAcctName())
+				.bind("trade_state", tradeBotData.getState())
+				.bind("trade_state_value", tradeBotData.getStateValue())
 				.bind("creator_address", tradeBotData.getCreatorAddress())
 				.bind("at_address", tradeBotData.getAtAddress())
 				.bind("updated_when", tradeBotData.getTimestamp())
@@ -137,11 +172,13 @@ public class HSQLDBCrossChainRepository implements CrossChainRepository {
 				.bind("trade_native_public_key", tradeBotData.getTradeNativePublicKey())
 				.bind("trade_native_public_key_hash", tradeBotData.getTradeNativePublicKeyHash())
 				.bind("trade_native_address", tradeBotData.getTradeNativeAddress())
-				.bind("secret", tradeBotData.getSecret()).bind("hash_of_secret", tradeBotData.getHashOfSecret())
+				.bind("secret", tradeBotData.getSecret())
+				.bind("hash_of_secret", tradeBotData.getHashOfSecret())
+				.bind("foreign_blockchain", tradeBotData.getForeignBlockchain())
 				.bind("trade_foreign_public_key", tradeBotData.getTradeForeignPublicKey())
 				.bind("trade_foreign_public_key_hash", tradeBotData.getTradeForeignPublicKeyHash())
-				.bind("bitcoin_amount", tradeBotData.getBitcoinAmount())
-				.bind("xprv58", tradeBotData.getXprv58())
+				.bind("foreign_amount", tradeBotData.getForeignAmount())
+				.bind("foreign_key", tradeBotData.getForeignKey())
 				.bind("last_transaction_signature", tradeBotData.getLastTransactionSignature())
 				.bind("locktime_a", tradeBotData.getLockTimeA())
 				.bind("receiving_account_info", tradeBotData.getReceivingAccountInfo());

src/main/java/org/qortal/repository/hsqldb/HSQLDBDatabaseUpdates.java

@@ -4,9 +4,12 @@ import java.sql.Connection;
 import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.sql.Statement;
+import java.util.Arrays;
+import java.util.stream.Collectors;
 
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
+import org.qortal.controller.tradebot.BitcoinACCTv1TradeBot;
 
 public class HSQLDBDatabaseUpdates {
 
@@ -618,6 +621,7 @@ public class HSQLDBDatabaseUpdates {
 
 				case 20:
 					// Trade bot
+					// See case 25 below for changes
 					stmt.execute("CREATE TABLE TradeBotStates (trade_private_key QortalKeySeed NOT NULL, trade_state TINYINT NOT NULL, "
 							+ "creator_address QortalAddress NOT NULL, at_address QortalAddress, updated_when BIGINT NOT NULL, qort_amount QortalAmount NOT NULL, "
 							+ "trade_native_public_key QortalPublicKey NOT NULL, trade_native_public_key_hash VARBINARY(32) NOT NULL, "
@@ -779,6 +783,45 @@ public class HSQLDBDatabaseUpdates {
 								+ "height INT NOT NULL, PRIMARY KEY (height, AT_address))");
 					break;
 
+				case 32:
+					// Multiple blockchains, ACCTs and trade-bots
+					stmt.execute("ALTER TABLE TradeBotStates ADD COLUMN acct_name VARCHAR(40) BEFORE trade_state");
+					stmt.execute("UPDATE TradeBotStates SET acct_name = 'BitcoinACCTv1' WHERE acct_name IS NULL");
+					stmt.execute("ALTER TABLE TradeBotStates ALTER COLUMN acct_name SET NOT NULL");
+
+					stmt.execute("ALTER TABLE TradeBotStates ALTER COLUMN trade_state RENAME TO trade_state_value");
+
+					stmt.execute("ALTER TABLE TradeBotStates ADD COLUMN trade_state VARCHAR(40) BEFORE trade_state_value");
+					// Any existing values will be BitcoinACCTv1
+					StringBuilder updateTradeBotStatesSql = new StringBuilder(1024);
+					updateTradeBotStatesSql.append("UPDATE TradeBotStates SET (trade_state) = (")
+							.append("SELECT state_name FROM (VALUES ")
+							.append(
+									Arrays.stream(BitcoinACCTv1TradeBot.State.values())
+									.map(state -> String.format("(%d, '%s')", state.value, state.name()))
+									.collect(Collectors.joining(", ")))
+							.append(") AS BitcoinACCTv1States (state_value, state_name) ")
+							.append("WHERE state_value = trade_state_value)");
+					stmt.execute(updateTradeBotStatesSql.toString());
+					stmt.execute("ALTER TABLE TradeBotStates ALTER COLUMN trade_state SET NOT NULL");
+
+					stmt.execute("ALTER TABLE TradeBotStates ADD COLUMN foreign_blockchain VARCHAR(40) BEFORE trade_foreign_public_key");
+
+					stmt.execute("ALTER TABLE TradeBotStates ALTER COLUMN bitcoin_amount RENAME TO foreign_amount");
+
+					stmt.execute("ALTER TABLE TradeBotStates ALTER COLUMN xprv58 RENAME TO foreign_key");
+
+					stmt.execute("ALTER TABLE TradeBotStates ALTER COLUMN secret SET NULL");
+					stmt.execute("ALTER TABLE TradeBotStates ALTER COLUMN hash_of_secret SET NULL");
+					break;
+
+				case 33:
+					// PRESENCE transactions
+					stmt.execute("CREATE TABLE IF NOT EXISTS PresenceTransactions ("
+							+ "signature Signature, nonce INT NOT NULL, presence_type INT NOT NULL, "
+							+ "timestamp_signature Signature NOT NULL, " + TRANSACTION_KEYS + ")");
+					break;
+
 				default:
 					// nothing to do
 					return false;

src/main/java/org/qortal/repository/hsqldb/HSQLDBRepository.java

@@ -16,6 +16,7 @@ import java.sql.Savepoint;
 import java.sql.Statement;
 import java.util.ArrayDeque;
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.Comparator;
 import java.util.Deque;
@@ -825,15 +826,18 @@ public class HSQLDBRepository implements Repository {
 	 * <p>
 	 * (Convenience method for HSQLDB repository subclasses).
 	 */
-	/* package */ static void temporaryValuesTableSql(StringBuilder stringBuilder, List<? extends Object> values, String tableName, String columnName) {
+	/* package */ static void temporaryValuesTableSql(StringBuilder stringBuilder, Collection<?> values, String tableName, String columnName) {
 		stringBuilder.append("(VALUES ");
 
-		for (int i = 0; i < values.size(); ++i) {
-			if (i != 0)
+		boolean first = true;
+		for (Object value : values) {
+			if (first)
+				first = false;
+			else
 				stringBuilder.append(", ");
 
 			stringBuilder.append("(");
-			stringBuilder.append(values.get(i));
+			stringBuilder.append(value);
 			stringBuilder.append(")");
 		}
 

src/main/java/org/qortal/repository/hsqldb/transaction/HSQLDBPresenceTransactionRepository.java

@@ -0,0 +1,57 @@
+package org.qortal.repository.hsqldb.transaction;
+
+import java.sql.ResultSet;
+import java.sql.SQLException;
+
+import org.qortal.data.transaction.BaseTransactionData;
+import org.qortal.data.transaction.PresenceTransactionData;
+import org.qortal.data.transaction.TransactionData;
+import org.qortal.repository.DataException;
+import org.qortal.repository.hsqldb.HSQLDBRepository;
+import org.qortal.repository.hsqldb.HSQLDBSaver;
+import org.qortal.transaction.PresenceTransaction.PresenceType;
+
+public class HSQLDBPresenceTransactionRepository extends HSQLDBTransactionRepository {
+
+	public HSQLDBPresenceTransactionRepository(HSQLDBRepository repository) {
+		this.repository = repository;
+	}
+
+	TransactionData fromBase(BaseTransactionData baseTransactionData) throws DataException {
+		String sql = "SELECT nonce, presence_type, timestamp_signature FROM PresenceTransactions WHERE signature = ?";
+
+		try (ResultSet resultSet = this.repository.checkedExecute(sql, baseTransactionData.getSignature())) {
+			if (resultSet == null)
+				return null;
+
+			int nonce = resultSet.getInt(1);
+			int presenceTypeValue = resultSet.getInt(2);
+			PresenceType presenceType = PresenceType.valueOf(presenceTypeValue);
+
+			byte[] timestampSignature = resultSet.getBytes(3);
+
+			return new PresenceTransactionData(baseTransactionData, nonce, presenceType, timestampSignature);
+		} catch (SQLException e) {
+			throw new DataException("Unable to fetch presence transaction from repository", e);
+		}
+	}
+
+	@Override
+	public void save(TransactionData transactionData) throws DataException {
+		PresenceTransactionData presenceTransactionData = (PresenceTransactionData) transactionData;
+
+		HSQLDBSaver saveHelper = new HSQLDBSaver("PresenceTransactions");
+
+		saveHelper.bind("signature", presenceTransactionData.getSignature())
+				.bind("nonce", presenceTransactionData.getNonce())
+				.bind("presence_type", presenceTransactionData.getPresenceType().value)
+				.bind("timestamp_signature", presenceTransactionData.getTimestampSignature());
+
+		try {
+			saveHelper.execute(this.repository);
+		} catch (SQLException e) {
+			throw new DataException("Unable to save chat transaction into repository", e);
+		}
+	}
+
+}

src/main/java/org/qortal/repository/hsqldb/transaction/HSQLDBTransactionRepository.java

@@ -1124,6 +1124,63 @@ public class HSQLDBTransactionRepository implements TransactionRepository {
 		}
 	}
 
+	@Override
+	public List<TransactionData> getUnconfirmedTransactions(TransactionType txType, byte[] creatorPublicKey) throws DataException {
+		if (txType == null && creatorPublicKey == null)
+			throw new IllegalArgumentException("At least one of txType or creatorPublicKey must be non-null");
+
+		StringBuilder sql = new StringBuilder(1024);
+		sql.append("SELECT signature FROM UnconfirmedTransactions ");
+		sql.append("JOIN Transactions USING (signature) ");
+		sql.append("WHERE ");
+
+		List<String> whereClauses = new ArrayList<>();
+		List<Object> bindParams = new ArrayList<>();
+
+		if (txType != null) {
+			whereClauses.add("type = ?");
+			bindParams.add(Integer.valueOf(txType.value));
+		}
+
+		if (creatorPublicKey != null) {
+			whereClauses.add("creator = ?");
+			bindParams.add(creatorPublicKey);
+		}
+
+		final int whereClausesSize = whereClauses.size();
+		for (int wci = 0; wci < whereClausesSize; ++wci) {
+			if (wci != 0)
+				sql.append(" AND ");
+
+			sql.append(whereClauses.get(wci));
+		}
+
+		sql.append("ORDER BY created_when, signature");
+
+		List<TransactionData> transactions = new ArrayList<>();
+
+		try (ResultSet resultSet = this.repository.checkedExecute(sql.toString(), bindParams.toArray())) {
+			if (resultSet == null)
+				return transactions;
+
+			do {
+				byte[] signature = resultSet.getBytes(1);
+
+				TransactionData transactionData = this.fromSignature(signature);
+
+				if (transactionData == null)
+					// Something inconsistent with the repository
+					throw new DataException(String.format("Unable to fetch unconfirmed transaction %s from repository?", Base58.encode(signature)));
+
+				transactions.add(transactionData);
+			} while (resultSet.next());
+
+			return transactions;
+		} catch (SQLException | DataException e) {
+			throw new DataException("Unable to fetch unconfirmed transactions from repository", e);
+		}
+	}
+
 	@Override
 	public void confirmTransaction(byte[] signature) throws DataException {
 		try {

src/main/java/org/qortal/settings/Settings.java

@@ -21,7 +21,8 @@ import org.eclipse.persistence.exceptions.XMLMarshalException;
 import org.eclipse.persistence.jaxb.JAXBContextFactory;
 import org.eclipse.persistence.jaxb.UnmarshallerProperties;
 import org.qortal.block.BlockChain;
-import org.qortal.crosschain.BTC.BitcoinNet;
+import org.qortal.crosschain.Bitcoin.BitcoinNet;
+import org.qortal.crosschain.Litecoin.LitecoinNet;
 
 // All properties to be converted to JSON via JAXB
 @XmlAccessorType(XmlAccessType.FIELD)
@@ -123,6 +124,7 @@ public class Settings {
 	// Which blockchains this node is running
 	private String blockchainConfig = null; // use default from resources
 	private BitcoinNet bitcoinNet = BitcoinNet.MAIN;
+	private LitecoinNet litecoinNet = LitecoinNet.MAIN;
 	// Also crosschain-related:
 	/** Whether to show SysTray pop-up notifications when trade-bot entries change state */
 	private boolean tradebotSystrayEnabled = false;
@@ -406,6 +408,10 @@ public class Settings {
 		return this.bitcoinNet;
 	}
 
+	public LitecoinNet getLitecoinNet() {
+		return this.litecoinNet;
+	}
+
 	public boolean isTradebotSystrayEnabled() {
 		return this.tradebotSystrayEnabled;
 	}

src/main/java/org/qortal/transaction/ChatTransaction.java

@@ -141,7 +141,7 @@ public class ChatTransaction extends Transaction {
 		// If we exist in the repository then we've been imported as unconfirmed,
 		// but we don't want to make it into a block, so return fake non-OK result.
 		if (this.repository.getTransactionRepository().exists(this.chatTransactionData.getSignature()))
-			return ValidationResult.CHAT;
+			return ValidationResult.INVALID_BUT_OK;
 
 		// If we have a recipient, check it is a valid address
 		String recipientAddress = chatTransactionData.getRecipient();
@@ -188,6 +188,16 @@ public class ChatTransaction extends Transaction {
 		return MemoryPoW.verify2(transactionBytes, POW_BUFFER_SIZE, difficulty, nonce);
 	}
 
+	/**
+	 * Ensure there's at least a skeleton account so people
+	 * can retrieve sender's public key using address, even if all their messages
+	 * expire.
+	 */
+	@Override
+	protected void onImportAsUnconfirmed() throws DataException {
+		this.getCreator().ensureAccount();
+	}
+
 	@Override
 	public void process() throws DataException {
 		throw new DataException("CHAT transactions should never be processed");

src/main/java/org/qortal/transaction/PresenceTransaction.java

@@ -0,0 +1,255 @@
+package org.qortal.transaction;
+
+import static java.util.Arrays.stream;
+import static java.util.stream.Collectors.toMap;
+
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.function.Supplier;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.qortal.account.Account;
+import org.qortal.controller.Controller;
+import org.qortal.crosschain.ACCT;
+import org.qortal.crosschain.SupportedBlockchain;
+import org.qortal.crypto.Crypto;
+import org.qortal.crypto.MemoryPoW;
+import org.qortal.data.at.ATData;
+import org.qortal.data.crosschain.CrossChainTradeData;
+import org.qortal.data.transaction.PresenceTransactionData;
+import org.qortal.data.transaction.TransactionData;
+import org.qortal.group.Group;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.transform.TransformationException;
+import org.qortal.transform.transaction.PresenceTransactionTransformer;
+import org.qortal.transform.transaction.TransactionTransformer;
+import org.qortal.utils.Base58;
+import org.qortal.utils.ByteArray;
+
+import com.google.common.primitives.Longs;
+
+public class PresenceTransaction extends Transaction {
+
+	private static final Logger LOGGER = LogManager.getLogger(PresenceTransaction.class);
+
+	// Properties
+	private PresenceTransactionData presenceTransactionData;
+
+	// Other useful constants
+	public static final int POW_BUFFER_SIZE = 8 * 1024 * 1024; // bytes
+	public static final int POW_DIFFICULTY = 8; // leading zero bits
+
+	public enum PresenceType {
+		REWARD_SHARE(0) {
+			@Override
+			public long getLifetime() {
+				return Controller.ONLINE_TIMESTAMP_MODULUS;
+			}
+		},
+		TRADE_BOT(1) {
+			@Override
+			public long getLifetime() {
+				return 30 * 60 * 1000L; // 30 minutes in milliseconds
+			}
+		};
+
+		public final int value;
+		private static final Map<Integer, PresenceType> map = stream(PresenceType.values()).collect(toMap(type -> type.value, type -> type));
+
+		PresenceType(int value) {
+			this.value = value;
+		}
+
+		public abstract long getLifetime();
+
+		public static PresenceType valueOf(int value) {
+			return map.get(value);
+		}
+
+		/** Returns PresenceType with matching <tt>name</tt> or <tt>null</tt> (instead of throwing IllegalArgumentException). */
+		public static PresenceType fromString(String name) {
+			try {
+				return PresenceType.valueOf(name);
+			} catch (IllegalArgumentException e) {
+				return null;
+			}
+		}
+	}
+
+	// Constructors
+
+	public PresenceTransaction(Repository repository, TransactionData transactionData) {
+		super(repository, transactionData);
+
+		this.presenceTransactionData = (PresenceTransactionData) this.transactionData;
+	}
+
+	// More information
+
+	@Override
+	public long getDeadline() {
+		return this.transactionData.getTimestamp() + this.presenceTransactionData.getPresenceType().getLifetime();
+	}
+
+	@Override
+	public List<String> getRecipientAddresses() throws DataException {
+		return Collections.emptyList();
+	}
+
+	// Navigation
+
+	public Account getSender() {
+		return this.getCreator();
+	}
+
+	// Processing
+
+	public void computeNonce() throws DataException {
+		byte[] transactionBytes;
+
+		try {
+			transactionBytes = TransactionTransformer.toBytesForSigning(this.transactionData);
+		} catch (TransformationException e) {
+			throw new RuntimeException("Unable to transform transaction to byte array for verification", e);
+		}
+
+		// Clear nonce from transactionBytes
+		PresenceTransactionTransformer.clearNonce(transactionBytes);
+
+		// Calculate nonce
+		this.presenceTransactionData.setNonce(MemoryPoW.compute2(transactionBytes, POW_BUFFER_SIZE, POW_DIFFICULTY));
+	}
+
+	/**
+	 * Returns whether PRESENCE transaction has valid txGroupId.
+	 * <p>
+	 * We insist on NO_GROUP.
+	 */
+	@Override
+	protected boolean isValidTxGroupId() throws DataException {
+		int txGroupId = this.transactionData.getTxGroupId();
+
+		return txGroupId == Group.NO_GROUP;
+	}
+
+	@Override
+	public ValidationResult isFeeValid() throws DataException {
+		if (this.transactionData.getFee() < 0)
+			return ValidationResult.NEGATIVE_FEE;
+
+		return ValidationResult.OK;
+	}
+
+	@Override
+	public boolean hasValidReference() throws DataException {
+		return true;
+	}
+
+	@Override
+	public ValidationResult isValid() throws DataException {
+		// Nonce checking is done via isSignatureValid() as that method is only called once per import
+
+		// If we exist in the repository then we've been imported as unconfirmed,
+		// but we don't want to make it into a block, so return fake non-OK result.
+		if (this.repository.getTransactionRepository().exists(this.presenceTransactionData.getSignature()))
+			return ValidationResult.INVALID_BUT_OK;
+
+		// We only support TRADE_BOT-type PRESENCE at this time
+		if (PresenceType.TRADE_BOT != this.presenceTransactionData.getPresenceType())
+			return ValidationResult.NOT_YET_RELEASED;
+
+		// Check timestamp signature
+		byte[] timestampSignature = this.presenceTransactionData.getTimestampSignature();
+		byte[] timestampBytes = Longs.toByteArray(this.presenceTransactionData.getTimestamp());
+		if (!Crypto.verify(this.transactionData.getCreatorPublicKey(), timestampSignature, timestampBytes))
+			return ValidationResult.INVALID_TIMESTAMP_SIGNATURE;
+
+		Map<ByteArray, Supplier<ACCT>> acctSuppliersByCodeHash = SupportedBlockchain.getAcctMap();
+		Set<ByteArray> codeHashes = acctSuppliersByCodeHash.keySet();
+		boolean isExecutable = true;
+
+		List<ATData> atsData = repository.getATRepository().getAllATsByFunctionality(codeHashes, isExecutable);
+
+		// Convert signer's public key to address form
+		String signerAddress = Crypto.toAddress(this.transactionData.getCreatorPublicKey());
+
+		for (ATData atData : atsData) {
+			ByteArray atCodeHash = new ByteArray(atData.getCodeHash());
+			Supplier<ACCT> acctSupplier = acctSuppliersByCodeHash.get(atCodeHash);
+			if (acctSupplier == null)
+				continue;
+
+			CrossChainTradeData crossChainTradeData = acctSupplier.get().populateTradeData(repository, atData);
+
+			// OK if signer's public key (in address form) matches Bob's trade public key (in address form)
+			if (signerAddress.equals(crossChainTradeData.qortalCreatorTradeAddress))
+				return ValidationResult.OK;
+
+			// OK if signer's public key (in address form) matches Alice's trade public key (in address form)
+			if (signerAddress.equals(crossChainTradeData.qortalPartnerAddress))
+				return ValidationResult.OK;
+		}
+
+		return ValidationResult.AT_UNKNOWN;
+	}
+
+	@Override
+	public boolean isSignatureValid() {
+		byte[] signature = this.transactionData.getSignature();
+		if (signature == null)
+			return false;
+
+		byte[] transactionBytes;
+
+		try {
+			transactionBytes = PresenceTransactionTransformer.toBytesForSigning(this.transactionData);
+		} catch (TransformationException e) {
+			throw new RuntimeException("Unable to transform transaction to byte array for verification", e);
+		}
+
+		if (!Crypto.verify(this.transactionData.getCreatorPublicKey(), signature, transactionBytes))
+			return false;
+
+		int nonce = this.presenceTransactionData.getNonce();
+
+		// Clear nonce from transactionBytes
+		PresenceTransactionTransformer.clearNonce(transactionBytes);
+
+		// Check nonce
+		return MemoryPoW.verify2(transactionBytes, POW_BUFFER_SIZE, POW_DIFFICULTY, nonce);
+	}
+
+	/**
+	 * Remove any PRESENCE transactions by the same signer that have older timestamps.
+	 */
+	@Override
+	protected void onImportAsUnconfirmed() throws DataException {
+		byte[] creatorPublicKey = this.transactionData.getCreatorPublicKey();
+		List<TransactionData> creatorsPresenceTransactions = this.repository.getTransactionRepository().getUnconfirmedTransactions(TransactionType.PRESENCE, creatorPublicKey);
+
+		if (creatorsPresenceTransactions.isEmpty())
+			return;
+
+		// List should contain oldest transaction first, so remove all but last from repository.
+		creatorsPresenceTransactions.remove(creatorsPresenceTransactions.size() - 1);
+		for (TransactionData transactionData : creatorsPresenceTransactions) {
+			LOGGER.info(() -> String.format("Deleting older PRESENCE transaction %s", Base58.encode(transactionData.getSignature())));
+			this.repository.getTransactionRepository().delete(transactionData);
+		}
+	}
+
+	@Override
+	public void process() throws DataException {
+		throw new DataException("PRESENCE transactions should never be processed");
+	}
+
+	@Override
+	public void orphan() throws DataException {
+		throw new DataException("PRESENCE transactions should never be orphaned");
+	}
+
+}

src/main/java/org/qortal/transaction/Transaction.java

@@ -83,7 +83,8 @@ public abstract class Transaction {
 		ENABLE_FORGING(37, false),
 		REWARD_SHARE(38, false),
 		ACCOUNT_LEVEL(39, false),
-		TRANSFER_PRIVS(40, false);
+		TRANSFER_PRIVS(40, false),
+		PRESENCE(41, false);
 
 		public final int value;
 		public final boolean needsApproval;
@@ -244,7 +245,8 @@ public abstract class Transaction {
 		ACCOUNT_ALREADY_EXISTS(92),
 		INVALID_GROUP_BLOCK_DELAY(93),
 		INCORRECT_NONCE(94),
-		CHAT(999),
+		INVALID_TIMESTAMP_SIGNATURE(95),
+		INVALID_BUT_OK(999),
 		NOT_YET_RELEASED(1000);
 
 		public final int value;
@@ -763,15 +765,20 @@ public abstract class Transaction {
 	/**
 	 * Import into our repository as a new, unconfirmed transaction.
 	 * <p>
-	 * Calls <tt>repository.saveChanges()</tt>
+	 * @implSpec <i>blocks</i> to obtain blockchain lock
+	 * <p>
+	 * If transaction is valid, then:
+	 * <ul>
+	 * <li>calls {@link Repository#discardChanges()}</li>
+	 * <li>calls {@link Controller#onNewTransaction(TransactionData, Peer)}</li>
+	 * </ul>
 	 * 
 	 * @throws DataException
 	 */
 	public ValidationResult importAsUnconfirmed() throws DataException {
 		// Attempt to acquire blockchain lock
 		ReentrantLock blockchainLock = Controller.getInstance().getBlockchainLock();
-		if (!blockchainLock.tryLock())
-			return ValidationResult.NO_BLOCKCHAIN_LOCK;
+		blockchainLock.lock();
 
 		try {
 			// Check transaction doesn't already exist
@@ -798,22 +805,30 @@ public abstract class Transaction {
 			repository.getTransactionRepository().save(transactionData);
 			repository.getTransactionRepository().unconfirmTransaction(transactionData);
 
-			/*
-			 * If CHAT transaction then ensure there's at least a skeleton account so people
-			 * can retrieve sender's public key using address, even if all their messages
-			 * expire.
-			 */
-			if (transactionData.getType() == TransactionType.CHAT)
-				this.getCreator().ensureAccount();
+			this.onImportAsUnconfirmed();
 
 			repository.saveChanges();
 
+			// Notify controller of new transaction
+			Controller.getInstance().onNewTransaction(transactionData);
+
 			return ValidationResult.OK;
 		} finally {
 			blockchainLock.unlock();
 		}
 	}
 
+	/**
+	 * Callback for when a transaction is imported as unconfirmed.
+	 * <p>
+	 * Called after transaction is added to repository, but before commit.
+	 * <p>
+	 * Blockchain lock is being held during this time.
+	 */
+	protected void onImportAsUnconfirmed() throws DataException {
+		/* To be optionally overridden */
+	}
+
 	/**
 	 * Returns whether transaction can be added to the blockchain.
 	 * <p>

src/main/java/org/qortal/transform/transaction/PresenceTransactionTransformer.java

@@ -0,0 +1,108 @@
+package org.qortal.transform.transaction;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.nio.ByteBuffer;
+
+import org.qortal.data.transaction.BaseTransactionData;
+import org.qortal.data.transaction.PresenceTransactionData;
+import org.qortal.data.transaction.TransactionData;
+import org.qortal.transaction.PresenceTransaction.PresenceType;
+import org.qortal.transaction.Transaction.TransactionType;
+import org.qortal.transform.TransformationException;
+import org.qortal.utils.Serialization;
+
+import com.google.common.primitives.Ints;
+import com.google.common.primitives.Longs;
+
+public class PresenceTransactionTransformer extends TransactionTransformer {
+
+	// Property lengths
+	private static final int NONCE_LENGTH = INT_LENGTH;
+	private static final int PRESENCE_TYPE_LENGTH = BYTE_LENGTH;
+	private static final int TIMESTAMP_SIGNATURE_LENGTH = SIGNATURE_LENGTH;
+
+	private static final int EXTRAS_LENGTH = NONCE_LENGTH + PRESENCE_TYPE_LENGTH + TIMESTAMP_SIGNATURE_LENGTH;
+
+	protected static final TransactionLayout layout;
+
+	static {
+		layout = new TransactionLayout();
+		layout.add("txType: " + TransactionType.PRESENCE.valueString, TransformationType.INT);
+		layout.add("timestamp", TransformationType.TIMESTAMP);
+		layout.add("transaction's groupID", TransformationType.INT);
+		layout.add("reference", TransformationType.SIGNATURE);
+		layout.add("sender's public key", TransformationType.PUBLIC_KEY);
+		layout.add("proof-of-work nonce", TransformationType.INT);
+		layout.add("presence type (reward-share=0, trade-bot=1)", TransformationType.BYTE);
+		layout.add("timestamp-signature", TransformationType.SIGNATURE);
+		layout.add("fee", TransformationType.AMOUNT);
+		layout.add("signature", TransformationType.SIGNATURE);
+	}
+
+	public static TransactionData fromByteBuffer(ByteBuffer byteBuffer) throws TransformationException {
+		long timestamp = byteBuffer.getLong();
+
+		int txGroupId = byteBuffer.getInt();
+
+		byte[] reference = new byte[REFERENCE_LENGTH];
+		byteBuffer.get(reference);
+
+		byte[] senderPublicKey = Serialization.deserializePublicKey(byteBuffer);
+
+		int nonce = byteBuffer.getInt();
+
+		PresenceType presenceType = PresenceType.valueOf(byteBuffer.get());
+
+		byte[] timestampSignature = new byte[SIGNATURE_LENGTH];
+		byteBuffer.get(timestampSignature);
+
+		long fee = byteBuffer.getLong();
+
+		byte[] signature = new byte[SIGNATURE_LENGTH];
+		byteBuffer.get(signature);
+
+		BaseTransactionData baseTransactionData = new BaseTransactionData(timestamp, txGroupId, reference, senderPublicKey, fee, signature);
+
+		return new PresenceTransactionData(baseTransactionData, nonce, presenceType, timestampSignature);
+	}
+
+	public static int getDataLength(TransactionData transactionData) {
+		return getBaseLength(transactionData) + EXTRAS_LENGTH;
+	}
+
+	public static byte[] toBytes(TransactionData transactionData) throws TransformationException {
+		try {
+			PresenceTransactionData presenceTransactionData = (PresenceTransactionData) transactionData;
+
+			ByteArrayOutputStream bytes = new ByteArrayOutputStream();
+
+			transformCommonBytes(transactionData, bytes);
+
+			bytes.write(Ints.toByteArray(presenceTransactionData.getNonce()));
+
+			bytes.write(presenceTransactionData.getPresenceType().value);
+
+			bytes.write(presenceTransactionData.getTimestampSignature());
+
+			bytes.write(Longs.toByteArray(presenceTransactionData.getFee()));
+
+			if (presenceTransactionData.getSignature() != null)
+				bytes.write(presenceTransactionData.getSignature());
+
+			return bytes.toByteArray();
+		} catch (IOException | ClassCastException e) {
+			throw new TransformationException(e);
+		}
+	}
+
+	public static void clearNonce(byte[] transactionBytes) {
+		int nonceIndex = TYPE_LENGTH + TIMESTAMP_LENGTH + GROUPID_LENGTH + REFERENCE_LENGTH + PUBLIC_KEY_LENGTH;
+
+		transactionBytes[nonceIndex++] = (byte) 0;
+		transactionBytes[nonceIndex++] = (byte) 0;
+		transactionBytes[nonceIndex++] = (byte) 0;
+		transactionBytes[nonceIndex++] = (byte) 0;
+	}
+
+}

src/main/java/org/qortal/utils/ByteArray.java

@@ -1,12 +1,19 @@
 package org.qortal.utils;
 
+import java.util.Arrays;
+import java.util.Objects;
+
 public class ByteArray implements Comparable<ByteArray> {
 
 	private int hash;
 	public final byte[] value;
 
 	public ByteArray(byte[] value) {
-		this.value = value;
+		this.value = Objects.requireNonNull(value);
+	}
+
+	public static ByteArray of(byte[] value) {
+		return new ByteArray(value);
 	}
 
 	@Override
@@ -14,36 +21,39 @@ public class ByteArray implements Comparable<ByteArray> {
 		if (this == other)
 			return true;
 
-		if (other instanceof ByteArray)
-			return this.compareTo((ByteArray) other) == 0;
-
 		if (other instanceof byte[])
-			return this.compareTo((byte[]) other) == 0;
+			return Arrays.equals(this.value, (byte[]) other);
+
+		if (other instanceof ByteArray)
+			return Arrays.equals(this.value, ((ByteArray) other).value);
 
 		return false;
 	}
 
 	@Override
 	public int hashCode() {
-		int h = hash;
-		if (h == 0 && value.length > 0) {
-			byte[] val = value;
+		int h = this.hash;
+		byte[] val = this.value;
+
+		if (h == 0 && val.length > 0) {
+			h = 1;
 
 			for (int i = 0; i < val.length; ++i)
 				h = 31 * h + val[i];
 
-			hash = h;
+			this.hash = h;
 		}
 		return h;
 	}
 
 	@Override
 	public int compareTo(ByteArray other) {
-		return this.compareTo(other.value);
+		Objects.requireNonNull(other);
+		return this.compareToPrimitive(other.value);
 	}
 
-	public int compareTo(byte[] otherValue) {
-		byte[] val = value;
+	public int compareToPrimitive(byte[] otherValue) {
+		byte[] val = this.value;
 
 		if (val.length < otherValue.length)
 			return -1;
@@ -63,4 +73,17 @@ public class ByteArray implements Comparable<ByteArray> {
 		return 0;
 	}
 
+	public String toString() {
+		StringBuilder sb = new StringBuilder(3 + this.value.length * 6);
+		sb.append("[");
+
+		if (this.value.length > 0)
+			sb.append(this.value[0]);
+
+		for (int i = 1; i < this.value.length; ++i)
+			sb.append(", ").append(this.value[i]);
+
+		return sb.append("]").toString();
+	}
+
 }

src/main/java/org/qortal/utils/Triple.java

@@ -1,42 +1,55 @@
 package org.qortal.utils;
 
-public class Triple<T, U, V> {
+public class Triple<A, B, C> {
 
-	private T a;
-	private U b;
-	private V c;
+	@FunctionalInterface
+	public interface TripleConsumer<A, B, C> {
+		public void accept(A a, B b, C c);
+	}
+
+	private A a;
+	private B b;
+	private C c;
+
+	public static <A, B, C> Triple<A, B, C> valueOf(A a, B b, C c) {
+		return new Triple<>(a, b, c);
+	}
 
 	public Triple() {
 	}
 
-	public Triple(T a, U b, V c) {
+	public Triple(A a, B b, C c) {
 		this.a = a;
 		this.b = b;
 		this.c = c;
 	}
 
-	public void setA(T a) {
+	public void setA(A a) {
 		this.a = a;
 	}
 
-	public T getA() {
+	public A getA() {
 		return a;
 	}
 
-	public void setB(U b) {
+	public void setB(B b) {
 		this.b = b;
 	}
 
-	public U getB() {
+	public B getB() {
 		return b;
 	}
 
-	public void setC(V c) {
+	public void setC(C c) {
 		this.c = c;
 	}
 
-	public V getC() {
+	public C getC() {
 		return c;
 	}
 
+	public void consume(TripleConsumer<A, B, C> consumer) {
+		consumer.accept(this.a, this.b, this.c);
+	}
+
 }

src/test/java/org/qortal/test/ByteArrayTests.java

@@ -3,10 +3,12 @@ package org.qortal.test;
 import static org.junit.Assert.*;
 
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Random;
+import java.util.TreeMap;
 
 import org.junit.Before;
 import org.junit.Test;
@@ -28,15 +30,13 @@ public class ByteArrayTests {
 		}
 	}
 
-	private void fillMap(Map<ByteArray, String> map) {
+	private static void fillMap(Map<ByteArray, String> map) {
 		for (byte[] testValue : testValues)
 			map.put(new ByteArray(testValue), String.valueOf(map.size()));
 	}
 
-	private byte[] dup(byte[] value) {
-		byte[] copiedValue = new byte[value.length];
-		System.arraycopy(value, 0, copiedValue, 0, copiedValue.length);
-		return copiedValue;
+	private static byte[] dup(byte[] value) {
+		return Arrays.copyOf(value, value.length);
 	}
 
 	@Test
@@ -92,7 +92,7 @@ public class ByteArrayTests {
 
 	@Test
 	@SuppressWarnings("unlikely-arg-type")
-	public void testMapContainsKey() {
+	public void testHashMapContainsKey() {
 		Map<ByteArray, String> testMap = new HashMap<>();
 		fillMap(testMap);
 
@@ -105,8 +105,59 @@ public class ByteArrayTests {
 
 		assertTrue("boxed not equal to primitive", ba.equals(copiedValue));
 
-		// This won't work because copiedValue.hashCode() will not match ba.hashCode()
-		assertFalse("Primitive shouldn't be found in map", testMap.containsKey(copiedValue));
+		/*
+		 * Unfortunately this doesn't work because HashMap::containsKey compares hashCodes first,
+		 * followed by object references, and copiedValue.hashCode() will never match ba.hashCode().
+		 */
+		assertFalse("Primitive shouldn't be found in HashMap", testMap.containsKey(copiedValue));
+	}
+
+	@Test
+	@SuppressWarnings("unlikely-arg-type")
+	public void testTreeMapContainsKey() {
+		Map<ByteArray, String> testMap = new TreeMap<>();
+		fillMap(testMap);
+
+		// Create new ByteArray object with an existing value.
+		byte[] copiedValue = dup(testValues.get(3));
+		ByteArray ba = new ByteArray(copiedValue);
+
+		// Confirm object can be found in map
+		assertTrue("ByteArray not found in map", testMap.containsKey(ba));
+
+		assertTrue("boxed not equal to primitive", ba.equals(copiedValue));
+
+		/*
+		 * Unfortunately this doesn't work because TreeMap::containsKey(x) wants to cast x to
+		 * Comparable<? super ByteArray> and byte[] does not fit <? super ByteArray>
+		 * so this throws a ClassCastException.
+		 */
+		try {
+			assertFalse("Primitive shouldn't be found in TreeMap", testMap.containsKey(copiedValue));
+			fail();
+		} catch (ClassCastException e) {
+			// Expected
+		}
+	}
+
+	@Test
+	@SuppressWarnings("unlikely-arg-type")
+	public void testArrayListContains() {
+		// Create new ByteArray object with an existing value.
+		byte[] copiedValue = dup(testValues.get(3));
+		ByteArray ba = new ByteArray(copiedValue);
+
+		// Confirm object can be found in list
+		assertTrue("ByteArray not found in map", testValues.contains(ba));
+
+		assertTrue("boxed not equal to primitive", ba.equals(copiedValue));
+
+		/*
+		 * Unfortunately this doesn't work because ArrayList::contains performs
+		 * copiedValue.equals(x) for each x in testValues, and byte[].equals()
+		 * simply compares object references, so will never match any ByteArray.
+		 */
+		assertFalse("Primitive shouldn't be found in ArrayList", testValues.contains(copiedValue));
 	}
 
 	@Test
@@ -116,8 +167,9 @@ public class ByteArrayTests {
 
 		byte[] copiedValue = dup(testValue);
 
+		System.out.println(String.format("Primitive hashCode: 0x%08x", testValue.hashCode()));
 		System.out.println(String.format("Boxed hashCode: 0x%08x", ba1.hashCode()));
-		System.out.println(String.format("Primitive hashCode: 0x%08x", copiedValue.hashCode()));
+		System.out.println(String.format("Duplicated primitive hashCode: 0x%08x", copiedValue.hashCode()));
 	}
 
 	@Test

src/test/java/org/qortal/test/PresenceTests.java

@@ -0,0 +1,133 @@
+package org.qortal.test;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.qortal.account.PrivateKeyAccount;
+import org.qortal.asset.Asset;
+import org.qortal.crosschain.BitcoinACCTv1;
+import org.qortal.data.transaction.BaseTransactionData;
+import org.qortal.data.transaction.DeployAtTransactionData;
+import org.qortal.data.transaction.PresenceTransactionData;
+import org.qortal.data.transaction.TransactionData;
+import org.qortal.group.Group;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.repository.RepositoryManager;
+import org.qortal.test.common.BlockUtils;
+import org.qortal.test.common.Common;
+import org.qortal.test.common.TransactionUtils;
+import org.qortal.transaction.DeployAtTransaction;
+import org.qortal.transaction.PresenceTransaction;
+import org.qortal.transaction.PresenceTransaction.PresenceType;
+import org.qortal.transaction.Transaction;
+import org.qortal.transaction.Transaction.ValidationResult;
+import org.qortal.utils.NTP;
+
+import com.google.common.primitives.Longs;
+
+import static org.junit.Assert.*;
+
+public class PresenceTests extends Common {
+
+	private static final byte[] BITCOIN_PKH = new byte[20];
+	private static final byte[] HASH_OF_SECRET_B = new byte[32];
+
+	private PrivateKeyAccount signer;
+	private Repository repository;
+
+	@Before
+	public void beforeTest() throws DataException {
+		Common.useDefaultSettings();
+
+		this.repository = RepositoryManager.getRepository();
+		this.signer = Common.getTestAccount(this.repository, "bob");
+
+		// We need to create corresponding test trade offer
+		byte[] creationBytes = BitcoinACCTv1.buildQortalAT(this.signer.getAddress(), BITCOIN_PKH, HASH_OF_SECRET_B,
+				0L, 0L,
+				7 * 24 * 60 * 60);
+
+		long txTimestamp = NTP.getTime();
+		byte[] lastReference = this.signer.getLastReference();
+
+		long fee = 0;
+		String name = "QORT-BTC cross-chain trade";
+		String description = "Qortal-Bitcoin cross-chain trade";
+		String atType = "ACCT";
+		String tags = "QORT-BTC ACCT";
+
+		BaseTransactionData baseTransactionData = new BaseTransactionData(txTimestamp, Group.NO_GROUP, lastReference, this.signer.getPublicKey(), fee, null);
+		TransactionData deployAtTransactionData = new DeployAtTransactionData(baseTransactionData, name, description, atType, tags, creationBytes, 1L, Asset.QORT);
+
+		Transaction deployAtTransaction = new DeployAtTransaction(repository, deployAtTransactionData);
+
+		fee = deployAtTransaction.calcRecommendedFee();
+		deployAtTransactionData.setFee(fee);
+
+		TransactionUtils.signAndImportValid(this.repository, deployAtTransactionData, this.signer);
+		BlockUtils.mintBlock(this.repository);
+	}
+
+	@After
+	public void afterTest() throws DataException {
+		if (this.repository != null)
+			this.repository.close();
+
+		this.repository = null;
+	}
+
+	@Test
+	public void validityTests() throws DataException {
+		long timestamp = System.currentTimeMillis();
+		byte[] timestampBytes = Longs.toByteArray(timestamp);
+
+		byte[] timestampSignature = this.signer.sign(timestampBytes);
+
+		assertTrue(isValid(Group.NO_GROUP, this.signer, timestamp, timestampSignature));
+
+		PrivateKeyAccount nonTrader = Common.getTestAccount(repository, "alice");
+		assertFalse(isValid(Group.NO_GROUP, nonTrader, timestamp, timestampSignature));
+	}
+
+	@Test
+	public void newestOnlyTests() throws DataException {
+		long OLDER_TIMESTAMP = System.currentTimeMillis() - 2000L;
+		long NEWER_TIMESTAMP = OLDER_TIMESTAMP + 1000L;
+
+		PresenceTransaction older = buildPresenceTransaction(Group.NO_GROUP, this.signer, OLDER_TIMESTAMP, null);
+		older.computeNonce();
+		TransactionUtils.signAndImportValid(repository, older.getTransactionData(), this.signer);
+
+		assertTrue(this.repository.getTransactionRepository().exists(older.getTransactionData().getSignature()));
+
+		PresenceTransaction newer = buildPresenceTransaction(Group.NO_GROUP, this.signer, NEWER_TIMESTAMP, null);
+		newer.computeNonce();
+		TransactionUtils.signAndImportValid(repository, newer.getTransactionData(), this.signer);
+
+		assertTrue(this.repository.getTransactionRepository().exists(newer.getTransactionData().getSignature()));
+		assertFalse(this.repository.getTransactionRepository().exists(older.getTransactionData().getSignature()));
+	}
+
+	private boolean isValid(int txGroupId, PrivateKeyAccount signer, long timestamp, byte[] timestampSignature) throws DataException {
+		Transaction transaction = buildPresenceTransaction(txGroupId, signer, timestamp, timestampSignature);
+		return transaction.isValidUnconfirmed() == ValidationResult.OK;
+	}
+
+	private PresenceTransaction buildPresenceTransaction(int txGroupId, PrivateKeyAccount signer, long timestamp, byte[] timestampSignature) throws DataException {
+		int nonce = 0;
+
+		byte[] reference = signer.getLastReference();
+		byte[] creatorPublicKey = signer.getPublicKey();
+		long fee = 0L;
+
+		if (timestampSignature == null)
+			timestampSignature = this.signer.sign(Longs.toByteArray(timestamp));
+
+		BaseTransactionData baseTransactionData = new BaseTransactionData(timestamp, txGroupId, reference, creatorPublicKey, fee, null);
+		PresenceTransactionData transactionData = new PresenceTransactionData(baseTransactionData, nonce, PresenceType.TRADE_BOT, timestampSignature);
+
+		return new PresenceTransaction(this.repository, transactionData);
+	}
+
+}

src/test/java/org/qortal/test/RepositoryTests.java

@@ -4,7 +4,7 @@ import org.junit.Before;
 import org.junit.Test;
 import org.qortal.account.Account;
 import org.qortal.asset.Asset;
-import org.qortal.crosschain.BTCACCT;
+import org.qortal.crosschain.BitcoinACCTv1;
 import org.qortal.crypto.Crypto;
 import org.qortal.repository.DataException;
 import org.qortal.repository.Repository;
@@ -398,7 +398,7 @@ public class RepositoryTests extends Common {
 	@Test
 	public void testAtLateral() {
 		try (final HSQLDBRepository hsqldb = (HSQLDBRepository) RepositoryManager.getRepository()) {
-			byte[] codeHash = BTCACCT.CODE_BYTES_HASH;
+			byte[] codeHash = BitcoinACCTv1.CODE_BYTES_HASH;
 			Boolean isFinished = null;
 			Integer dataByteOffset = null;
 			Long expectedValue = null;

src/test/java/org/qortal/test/api/CrossChainApiTests.java

@@ -4,10 +4,13 @@ import org.junit.Before;
 import org.junit.Test;
 import org.qortal.api.ApiError;
 import org.qortal.api.resource.CrossChainResource;
+import org.qortal.crosschain.SupportedBlockchain;
 import org.qortal.test.common.ApiCommon;
 
 public class CrossChainApiTests extends ApiCommon {
 
+	private static final SupportedBlockchain SPECIFIC_BLOCKCHAIN = null;
+
 	private CrossChainResource crossChainResource;
 
 	@Before
@@ -17,12 +20,13 @@ public class CrossChainApiTests extends ApiCommon {
 
 	@Test
 	public void testGetTradeOffers() {
-		assertNoApiError((limit, offset, reverse) -> this.crossChainResource.getTradeOffers(limit, offset, reverse));
+		assertNoApiError((limit, offset, reverse) -> this.crossChainResource.getTradeOffers(SPECIFIC_BLOCKCHAIN, limit, offset, reverse));
 	}
 
 	@Test
 	public void testGetCompletedTrades() {
-		assertNoApiError((limit, offset, reverse) -> this.crossChainResource.getCompletedTrades(System.currentTimeMillis() /*minimumTimestamp*/, limit, offset, reverse));
+		long minimumTimestamp = System.currentTimeMillis();
+		assertNoApiError((limit, offset, reverse) -> this.crossChainResource.getCompletedTrades(SPECIFIC_BLOCKCHAIN, minimumTimestamp, limit, offset, reverse));
 	}
 
 	@Test
@@ -31,8 +35,8 @@ public class CrossChainApiTests extends ApiCommon {
 		Integer offset = null;
 		Boolean reverse = null;
 
-		assertApiError(ApiError.INVALID_CRITERIA, () -> this.crossChainResource.getCompletedTrades(-1L /*minimumTimestamp*/, limit, offset, reverse));
-		assertApiError(ApiError.INVALID_CRITERIA, () -> this.crossChainResource.getCompletedTrades(0L /*minimumTimestamp*/, limit, offset, reverse));
+		assertApiError(ApiError.INVALID_CRITERIA, () -> this.crossChainResource.getCompletedTrades(SPECIFIC_BLOCKCHAIN, -1L /*minimumTimestamp*/, limit, offset, reverse));
+		assertApiError(ApiError.INVALID_CRITERIA, () -> this.crossChainResource.getCompletedTrades(SPECIFIC_BLOCKCHAIN, 0L /*minimumTimestamp*/, limit, offset, reverse));
 	}
 
 }

src/test/java/org/qortal/test/apps/BTCACCTTests.java

@@ -1,327 +0,0 @@
-package org.qortal.test.apps;
-
-import java.io.File;
-import java.net.UnknownHostException;
-import java.security.MessageDigest;
-import java.security.NoSuchAlgorithmException;
-import java.security.SecureRandom;
-import java.security.Security;
-import java.util.concurrent.CancellationException;
-import java.util.concurrent.ExecutionException;
-
-import org.bitcoinj.core.Address;
-import org.bitcoinj.core.Coin;
-import org.bitcoinj.core.ECKey;
-import org.bitcoinj.core.InsufficientMoneyException;
-import org.bitcoinj.core.LegacyAddress;
-import org.bitcoinj.core.NetworkParameters;
-import org.bitcoinj.core.Sha256Hash;
-import org.bitcoinj.core.Transaction;
-import org.bitcoinj.core.Transaction.SigHash;
-import org.bitcoinj.core.TransactionBroadcast;
-import org.bitcoinj.core.TransactionInput;
-import org.bitcoinj.core.TransactionOutPoint;
-import org.bitcoinj.crypto.TransactionSignature;
-import org.bitcoinj.kits.WalletAppKit;
-import org.bitcoinj.params.TestNet3Params;
-import org.bitcoinj.script.Script;
-import org.bitcoinj.script.Script.ScriptType;
-import org.bitcoinj.script.ScriptBuilder;
-import org.bitcoinj.script.ScriptChunk;
-import org.bitcoinj.script.ScriptOpCodes;
-import org.bitcoinj.wallet.WalletTransaction.Pool;
-import org.bouncycastle.jce.provider.BouncyCastleProvider;
-
-import com.google.common.hash.HashCode;
-import com.google.common.primitives.Bytes;
-
-/**
- * Initiator must be Qortal-chain so that initiator can send initial message to BTC P2SH then Qortal can scan for P2SH add send corresponding message to Qortal AT.
- *
- * Initiator (wants QORT, has BTC)
- * 		Funds BTC P2SH address
- * 
- * Responder (has QORT, wants BTC)
- * 		Builds Qortal ACCT AT and funds it with QORT
- * 
- * Initiator sends recipient+secret+script as input to BTC P2SH address, releasing BTC amount - fees to responder
- * 
- * Qortal nodes scan for P2SH output, checks amount and recipient and if ok sends secret to Qortal ACCT AT
- * (Or it's possible to feed BTC transaction details into Qortal AT so it can check them itself?)
- * 
- * Qortal ACCT AT sends its QORT to initiator
- *
- */
-
-public class BTCACCTTests {
-
-	private static final long TIMEOUT = 600L;
-	private static final Coin sendValue = Coin.valueOf(6_000L);
-	private static final Coin fee = Coin.valueOf(2_000L);
-
-	private static final byte[] senderPrivKeyBytes = HashCode.fromString("027fb5828c5e201eaf6de4cd3b0b340d16a191ef848cd691f35ef8f727358c9c").asBytes();
-	private static final byte[] recipientPrivKeyBytes = HashCode.fromString("ec199a4abc9d3bf024349e397535dfee9d287e174aeabae94237eb03a0118c03").asBytes();
-
-	// The following need to be updated manually
-	private static final String prevTxHash = "70ee97f20afea916c2e7b47f6abf3c75f97c4c2251b4625419406a2dd47d16b5";
-	private static final Coin prevTxBalance = Coin.valueOf(562_000L); // This is NOT the amount but the unspent balance
-	private static final long prevTxOutputIndex = 1L;
-
-	// For when we want to re-run
-	private static final byte[] prevSecret = HashCode.fromString("30a13291e350214bea5318f990b77bc11d2cb709f7c39859f248bef396961dcc").asBytes();
-	private static final long prevLockTime = 1539347892L;
-	private static final boolean usePreviousFundingTx = false;
-
-	private static final boolean doRefundNotRedeem = false;
-
-	public static void main(String[] args) throws NoSuchAlgorithmException, InsufficientMoneyException, InterruptedException, ExecutionException, UnknownHostException {
-		Security.insertProviderAt(new BouncyCastleProvider(), 0);
-
-		byte[] secret = new byte[32];
-		new SecureRandom().nextBytes(secret);
-
-		if (usePreviousFundingTx)
-			secret = prevSecret;
-
-		System.out.println("Secret: " + HashCode.fromBytes(secret).toString());
-
-		MessageDigest sha256Digester = MessageDigest.getInstance("SHA-256");
-
-		byte[] secretHash = sha256Digester.digest(secret);
-		String secretHashHex = HashCode.fromBytes(secretHash).toString();
-
-		System.out.println("SHA256(secret): " + secretHashHex);
-
-		NetworkParameters params = TestNet3Params.get();
-		// NetworkParameters params = RegTestParams.get();
-		System.out.println("Network: " + params.getId());
-
-		WalletAppKit kit = new WalletAppKit(params, new File("."), "btc-tests");
-
-		kit.setBlockingStartup(false);
-		kit.startAsync();
-		kit.awaitRunning();
-
-		long now = System.currentTimeMillis() / 1000L;
-		long lockTime = now + TIMEOUT;
-
-		if (usePreviousFundingTx)
-			lockTime = prevLockTime;
-
-		System.out.println("LockTime: " + lockTime);
-
-		ECKey senderKey = ECKey.fromPrivate(senderPrivKeyBytes);
-		kit.wallet().importKey(senderKey);
-		ECKey recipientKey = ECKey.fromPrivate(recipientPrivKeyBytes);
-		kit.wallet().importKey(recipientKey);
-
-		byte[] senderPubKey = senderKey.getPubKey();
-		System.out.println("Sender address: " + Address.fromKey(params, senderKey, ScriptType.P2PKH).toString());
-		System.out.println("Sender pubkey: " + HashCode.fromBytes(senderPubKey).toString());
-
-		byte[] recipientPubKey = recipientKey.getPubKey();
-		System.out.println("Recipient address: " + Address.fromKey(params, recipientKey, ScriptType.P2PKH).toString());
-		System.out.println("Recipient pubkey: " + HashCode.fromBytes(recipientPubKey).toString());
-
-		byte[] redeemScriptBytes = buildRedeemScript(secret, senderPubKey, recipientPubKey, lockTime);
-		System.out.println("Redeem script: " + HashCode.fromBytes(redeemScriptBytes).toString());
-
-		byte[] redeemScriptHash = hash160(redeemScriptBytes);
-
-		Address p2shAddress = LegacyAddress.fromScriptHash(params, redeemScriptHash);
-		System.out.println("P2SH address: " + p2shAddress.toString());
-
-		// Send amount to P2SH address
-		Transaction fundingTransaction = buildFundingTransaction(params, Sha256Hash.wrap(prevTxHash), prevTxOutputIndex, prevTxBalance, senderKey,
-				sendValue.add(fee), redeemScriptHash);
-
-		System.out.println("Sending " + sendValue.add(fee).toPlainString() + " to " + p2shAddress.toString());
-		if (!usePreviousFundingTx)
-			broadcastWithConfirmation(kit, fundingTransaction);
-
-		if (doRefundNotRedeem) {
-			// Refund
-			System.out.println("Refunding " + sendValue.toPlainString() + " back to " + Address.fromKey(params, senderKey, ScriptType.P2PKH).toString());
-
-			now = System.currentTimeMillis() / 1000L;
-			long refundLockTime = now - 60 * 30; // 30 minutes in the past, needs to before 'now' and before "median block time" (median of previous 11 block
-													// timestamps)
-			if (refundLockTime < lockTime)
-				throw new RuntimeException("Too soon to refund");
-
-			TransactionOutPoint fundingOutPoint = new TransactionOutPoint(params, 0, fundingTransaction);
-			Transaction refundTransaction = buildRefundTransaction(params, fundingOutPoint, senderKey, sendValue, redeemScriptBytes, refundLockTime);
-			broadcastWithConfirmation(kit, refundTransaction);
-		} else {
-			// Redeem
-			System.out.println("Redeeming " + sendValue.toPlainString() + " to " + Address.fromKey(params, recipientKey, ScriptType.P2PKH).toString());
-
-			TransactionOutPoint fundingOutPoint = new TransactionOutPoint(params, 0, fundingTransaction);
-			Transaction redeemTransaction = buildRedeemTransaction(params, fundingOutPoint, recipientKey, sendValue, secret, redeemScriptBytes);
-			broadcastWithConfirmation(kit, redeemTransaction);
-		}
-
-		kit.wallet().cleanup();
-
-		for (Transaction transaction : kit.wallet().getTransactionPool(Pool.PENDING).values())
-			System.out.println("Pending tx: " + transaction.getTxId().toString());
-	}
-
-	private static final byte[] redeemScript1 = HashCode.fromString("76a820").asBytes();
-	private static final byte[] redeemScript2 = HashCode.fromString("87637576a914").asBytes();
-	private static final byte[] redeemScript3 = HashCode.fromString("88ac6704").asBytes();
-	private static final byte[] redeemScript4 = HashCode.fromString("b17576a914").asBytes();
-	private static final byte[] redeemScript5 = HashCode.fromString("88ac68").asBytes();
-
-	private static byte[] buildRedeemScript(byte[] secret, byte[] senderPubKey, byte[] recipientPubKey, long lockTime) {
-		try {
-			MessageDigest sha256Digester = MessageDigest.getInstance("SHA-256");
-
-			byte[] secretHash = sha256Digester.digest(secret);
-			byte[] senderPubKeyHash = hash160(senderPubKey);
-			byte[] recipientPubKeyHash = hash160(recipientPubKey);
-
-			return Bytes.concat(redeemScript1, secretHash, redeemScript2, recipientPubKeyHash, redeemScript3, toLEByteArray((int) (lockTime & 0xffffffffL)),
-					redeemScript4, senderPubKeyHash, redeemScript5);
-		} catch (NoSuchAlgorithmException e) {
-			throw new RuntimeException("Message digest unsupported", e);
-		}
-	}
-
-	private static byte[] hash160(byte[] input) {
-		try {
-			MessageDigest rmd160Digester = MessageDigest.getInstance("RIPEMD160");
-			MessageDigest sha256Digester = MessageDigest.getInstance("SHA-256");
-
-			return rmd160Digester.digest(sha256Digester.digest(input));
-		} catch (NoSuchAlgorithmException e) {
-			throw new RuntimeException("Message digest unsupported", e);
-		}
-	}
-
-	private static Transaction buildFundingTransaction(NetworkParameters params, Sha256Hash prevTxHash, long outputIndex, Coin balance, ECKey sigKey, Coin value,
-			byte[] redeemScriptHash) {
-		Transaction fundingTransaction = new Transaction(params);
-
-		// Outputs (needed before input so inputs can be signed)
-		// Fixed amount to P2SH
-		fundingTransaction.addOutput(value, ScriptBuilder.createP2SHOutputScript(redeemScriptHash));
-		// Change to sender
-		fundingTransaction.addOutput(balance.minus(value).minus(fee), ScriptBuilder.createOutputScript(Address.fromKey(params, sigKey, ScriptType.P2PKH)));
-
-		// Input
-		// We create fake "to address" scriptPubKey for prev tx so our spending input is P2PKH type
-		Script fakeScriptPubKey = ScriptBuilder.createOutputScript(Address.fromKey(params, sigKey, ScriptType.P2PKH));
-		TransactionOutPoint prevOut = new TransactionOutPoint(params, outputIndex, prevTxHash);
-		fundingTransaction.addSignedInput(prevOut, fakeScriptPubKey, sigKey);
-
-		return fundingTransaction;
-	}
-
-	private static Transaction buildRedeemTransaction(NetworkParameters params, TransactionOutPoint fundingOutPoint, ECKey recipientKey, Coin value, byte[] secret,
-			byte[] redeemScriptBytes) {
-		Transaction redeemTransaction = new Transaction(params);
-		redeemTransaction.setVersion(2);
-
-		// Outputs
-		redeemTransaction.addOutput(value, ScriptBuilder.createOutputScript(Address.fromKey(params, recipientKey, ScriptType.P2PKH)));
-
-		// Input
-		byte[] recipientPubKey = recipientKey.getPubKey();
-		ScriptBuilder scriptBuilder = new ScriptBuilder();
-		scriptBuilder.addChunk(new ScriptChunk(recipientPubKey.length, recipientPubKey));
-		scriptBuilder.addChunk(new ScriptChunk(secret.length, secret));
-		scriptBuilder.addChunk(new ScriptChunk(ScriptOpCodes.OP_PUSHDATA1, redeemScriptBytes));
-		byte[] scriptPubKey = scriptBuilder.build().getProgram();
-
-		TransactionInput input = new TransactionInput(params, null, scriptPubKey, fundingOutPoint);
-		input.setSequenceNumber(0xffffffffL); // Final
-		redeemTransaction.addInput(input);
-
-		// Generate transaction signature for input
-		boolean anyoneCanPay = false;
-		Sha256Hash hash = redeemTransaction.hashForSignature(0, redeemScriptBytes, SigHash.ALL, anyoneCanPay);
-		System.out.println("redeem transaction's input hash: " + hash.toString());
-
-		ECKey.ECDSASignature ecSig = recipientKey.sign(hash);
-		TransactionSignature txSig = new TransactionSignature(ecSig, SigHash.ALL, anyoneCanPay);
-		byte[] txSigBytes = txSig.encodeToBitcoin();
-		System.out.println("redeem transaction's signature: " + HashCode.fromBytes(txSigBytes).toString());
-
-		// Prepend signature to input
-		scriptBuilder.addChunk(0, new ScriptChunk(txSigBytes.length, txSigBytes));
-		input.setScriptSig(scriptBuilder.build());
-
-		return redeemTransaction;
-	}
-
-	private static Transaction buildRefundTransaction(NetworkParameters params, TransactionOutPoint fundingOutPoint, ECKey senderKey, Coin value,
-			byte[] redeemScriptBytes, long lockTime) {
-		Transaction refundTransaction = new Transaction(params);
-		refundTransaction.setVersion(2);
-
-		// Outputs
-		refundTransaction.addOutput(value, ScriptBuilder.createOutputScript(Address.fromKey(params, senderKey, ScriptType.P2PKH)));
-
-		// Input
-		byte[] recipientPubKey = senderKey.getPubKey();
-		ScriptBuilder scriptBuilder = new ScriptBuilder();
-		scriptBuilder.addChunk(new ScriptChunk(recipientPubKey.length, recipientPubKey));
-		scriptBuilder.addChunk(new ScriptChunk(ScriptOpCodes.OP_PUSHDATA1, redeemScriptBytes));
-		byte[] scriptPubKey = scriptBuilder.build().getProgram();
-
-		TransactionInput input = new TransactionInput(params, null, scriptPubKey, fundingOutPoint);
-		input.setSequenceNumber(0);
-		refundTransaction.addInput(input);
-
-		// Set locktime after input but before input signature is generated
-		refundTransaction.setLockTime(lockTime);
-
-		// Generate transaction signature for input
-		boolean anyoneCanPay = false;
-		Sha256Hash hash = refundTransaction.hashForSignature(0, redeemScriptBytes, SigHash.ALL, anyoneCanPay);
-		System.out.println("refund transaction's input hash: " + hash.toString());
-
-		ECKey.ECDSASignature ecSig = senderKey.sign(hash);
-		TransactionSignature txSig = new TransactionSignature(ecSig, SigHash.ALL, anyoneCanPay);
-		byte[] txSigBytes = txSig.encodeToBitcoin();
-		System.out.println("refund transaction's signature: " + HashCode.fromBytes(txSigBytes).toString());
-
-		// Prepend signature to input
-		scriptBuilder.addChunk(0, new ScriptChunk(txSigBytes.length, txSigBytes));
-		input.setScriptSig(scriptBuilder.build());
-
-		return refundTransaction;
-	}
-
-	private static void broadcastWithConfirmation(WalletAppKit kit, Transaction transaction) {
-		System.out.println("Broadcasting tx: " + transaction.getTxId().toString());
-		System.out.println("TX hex: " + HashCode.fromBytes(transaction.bitcoinSerialize()).toString());
-
-		System.out.println("Number of connected peers: " + kit.peerGroup().numConnectedPeers());
-		TransactionBroadcast txBroadcast = kit.peerGroup().broadcastTransaction(transaction);
-
-		try {
-			txBroadcast.future().get();
-		} catch (InterruptedException | ExecutionException e) {
-			throw new RuntimeException("Transaction broadcast failed", e);
-		}
-
-		// wait for confirmation
-		System.out.println("Waiting for confirmation of tx: " + transaction.getTxId().toString());
-
-		try {
-			transaction.getConfidence().getDepthFuture(1).get();
-		} catch (CancellationException | ExecutionException | InterruptedException e) {
-			throw new RuntimeException("Transaction confirmation failed", e);
-		}
-
-		System.out.println("Confirmed tx: " + transaction.getTxId().toString());
-	}
-
-	/** Convert int to little-endian byte array */
-	private static byte[] toLEByteArray(int value) {
-		return new byte[] { (byte) (value), (byte) (value >> 8), (byte) (value >> 16), (byte) (value >> 24) };
-	}
-
-}

src/test/java/org/qortal/test/btcacct/BuildP2SH.java

@@ -1,126 +0,0 @@
-package org.qortal.test.btcacct;
-
-import java.security.Security;
-import java.time.Instant;
-import java.time.LocalDateTime;
-import java.time.ZoneOffset;
-
-import org.bitcoinj.core.Address;
-import org.bitcoinj.core.Coin;
-import org.bitcoinj.core.LegacyAddress;
-import org.bitcoinj.core.NetworkParameters;
-import org.bitcoinj.script.Script.ScriptType;
-import org.bouncycastle.jce.provider.BouncyCastleProvider;
-import org.qortal.controller.Controller;
-import org.qortal.crosschain.BTC;
-import org.qortal.crosschain.BTCP2SH;
-import org.qortal.crypto.Crypto;
-import org.qortal.repository.DataException;
-import org.qortal.repository.Repository;
-import org.qortal.repository.RepositoryFactory;
-import org.qortal.repository.RepositoryManager;
-import org.qortal.repository.hsqldb.HSQLDBRepositoryFactory;
-import org.qortal.settings.Settings;
-
-import com.google.common.hash.HashCode;
-
-public class BuildP2SH {
-
-	private static void usage(String error) {
-		if (error != null)
-			System.err.println(error);
-
-		System.err.println(String.format("usage: BuildP2SH <refund-BTC-P2PKH> <BTC-amount> <redeem-BTC-P2PKH> <HASH160-of-secret> <locktime> (<BTC-redeem/refund-fee>)"));
-		System.err.println(String.format("example: BuildP2SH "
-				+ "mrTDPdM15cFWJC4g223BXX5snicfVJBx6M \\\n"
-				+ "\t0.00008642 \\\n"
-				+ "\tn2N5VKrzq39nmuefZwp3wBiF4icdXX2B6o \\\n"
-				+ "\tdaf59884b4d1aec8c1b17102530909ee43c0151a \\\n"
-				+ "\t1585920000"));
-		System.exit(1);
-	}
-
-	public static void main(String[] args) {
-		if (args.length < 5 || args.length > 6)
-			usage(null);
-
-		Security.insertProviderAt(new BouncyCastleProvider(), 0);
-		Settings.fileInstance("settings-test.json");
-
-		BTC btc = BTC.getInstance();
-		NetworkParameters params = btc.getNetworkParameters();
-
-		Address refundBitcoinAddress = null;
-		Coin bitcoinAmount = null;
-		Address redeemBitcoinAddress = null;
-		byte[] secretHash = null;
-		int lockTime = 0;
-		Coin bitcoinFee = Common.DEFAULT_BTC_FEE;
-
-		int argIndex = 0;
-		try {
-			refundBitcoinAddress = Address.fromString(params, args[argIndex++]);
-			if (refundBitcoinAddress.getOutputScriptType() != ScriptType.P2PKH)
-				usage("Refund BTC address must be in P2PKH form");
-
-			bitcoinAmount = Coin.parseCoin(args[argIndex++]);
-
-			redeemBitcoinAddress = Address.fromString(params, args[argIndex++]);
-			if (redeemBitcoinAddress.getOutputScriptType() != ScriptType.P2PKH)
-				usage("Redeem BTC address must be in P2PKH form");
-
-			secretHash = HashCode.fromString(args[argIndex++]).asBytes();
-			if (secretHash.length != 20)
-				usage("Hash of secret must be 20 bytes");
-
-			lockTime = Integer.parseInt(args[argIndex++]);
-			int refundTimeoutDelay = lockTime - (int) (System.currentTimeMillis() / 1000L);
-			if (refundTimeoutDelay < 600 || refundTimeoutDelay > 30 * 24 * 60 * 60)
-				usage("Locktime (seconds) should be at between 10 minutes and 1 month from now");
-
-			if (args.length > argIndex)
-				bitcoinFee = Coin.parseCoin(args[argIndex++]);
-		} catch (IllegalArgumentException e) {
-			usage(String.format("Invalid argument %d: %s", argIndex, e.getMessage()));
-		}
-
-		try {
-			RepositoryFactory repositoryFactory = new HSQLDBRepositoryFactory(Controller.getRepositoryUrl());
-			RepositoryManager.setRepositoryFactory(repositoryFactory);
-		} catch (DataException e) {
-			throw new RuntimeException("Repository startup issue: " + e.getMessage());
-		}
-
-		try (final Repository repository = RepositoryManager.getRepository()) {
-			System.out.println("Confirm the following is correct based on the info you've given:");
-
-			System.out.println(String.format("Refund Bitcoin address: %s", refundBitcoinAddress));
-			System.out.println(String.format("Bitcoin redeem amount: %s", bitcoinAmount.toPlainString()));
-
-			System.out.println(String.format("Redeem Bitcoin address: %s", redeemBitcoinAddress));
-			System.out.println(String.format("Redeem miner's fee: %s", BTC.format(bitcoinFee)));
-
-			System.out.println(String.format("Redeem script lockTime: %s (%d)", LocalDateTime.ofInstant(Instant.ofEpochSecond(lockTime), ZoneOffset.UTC), lockTime));
-			System.out.println(String.format("Hash of secret: %s", HashCode.fromBytes(secretHash)));
-
-			byte[] redeemScriptBytes = BTCP2SH.buildScript(refundBitcoinAddress.getHash(), lockTime, redeemBitcoinAddress.getHash(), secretHash);
-			System.out.println(String.format("Redeem script: %s", HashCode.fromBytes(redeemScriptBytes)));
-
-			byte[] redeemScriptHash = Crypto.hash160(redeemScriptBytes);
-
-			Address p2shAddress = LegacyAddress.fromScriptHash(params, redeemScriptHash);
-			System.out.println(String.format("P2SH address: %s", p2shAddress));
-
-			bitcoinAmount = bitcoinAmount.add(bitcoinFee);
-
-			// Fund P2SH
-			System.out.println(String.format("\nYou need to fund %s with %s (includes redeem/refund fee of %s)",
-					p2shAddress.toString(), BTC.format(bitcoinAmount), BTC.format(bitcoinFee)));
-
-			System.out.println("Once this is done, responder should run Respond to check P2SH funding and create AT");
-		} catch (DataException e) {
-			throw new RuntimeException("Repository issue: " + e.getMessage());
-		}
-	}
-
-}

src/test/java/org/qortal/test/btcacct/CheckP2SH.java

@@ -1,170 +0,0 @@
-package org.qortal.test.btcacct;
-
-import java.security.Security;
-import java.time.Instant;
-import java.time.LocalDateTime;
-import java.time.ZoneOffset;
-import java.util.List;
-
-import org.bitcoinj.core.Address;
-import org.bitcoinj.core.Coin;
-import org.bitcoinj.core.LegacyAddress;
-import org.bitcoinj.core.NetworkParameters;
-import org.bitcoinj.core.TransactionOutput;
-import org.bitcoinj.script.Script.ScriptType;
-import org.bouncycastle.jce.provider.BouncyCastleProvider;
-import org.qortal.controller.Controller;
-import org.qortal.crosschain.BTC;
-import org.qortal.crosschain.BTCP2SH;
-import org.qortal.crosschain.BitcoinException;
-import org.qortal.crypto.Crypto;
-import org.qortal.repository.DataException;
-import org.qortal.repository.Repository;
-import org.qortal.repository.RepositoryFactory;
-import org.qortal.repository.RepositoryManager;
-import org.qortal.repository.hsqldb.HSQLDBRepositoryFactory;
-import org.qortal.settings.Settings;
-
-import com.google.common.hash.HashCode;
-
-public class CheckP2SH {
-
-	private static void usage(String error) {
-		if (error != null)
-			System.err.println(error);
-
-		System.err.println(String.format("usage: CheckP2SH <P2SH-address> <refund-BTC-P2PKH> <BTC-amount> <redeem-BTC-P2PKH> <HASH160-of-secret> <locktime> (<BTC-redeem/refund-fee>)"));
-		System.err.println(String.format("example: CheckP2SH "
-				+ "2NEZboTLhBDPPQciR7sExBhy3TsDi7wV3Cv \\\n"
-				+ "mrTDPdM15cFWJC4g223BXX5snicfVJBx6M \\\n"
-				+ "\t0.00008642 \\\n"
-				+ "\tn2N5VKrzq39nmuefZwp3wBiF4icdXX2B6o \\\n"
-				+ "\tdaf59884b4d1aec8c1b17102530909ee43c0151a \\\n"
-				+ "\t1585920000"));
-		System.exit(1);
-	}
-
-	public static void main(String[] args) {
-		if (args.length < 6 || args.length > 7)
-			usage(null);
-
-		Security.insertProviderAt(new BouncyCastleProvider(), 0);
-		Settings.fileInstance("settings-test.json");
-
-		BTC btc = BTC.getInstance();
-		NetworkParameters params = btc.getNetworkParameters();
-
-		Address p2shAddress = null;
-		Address refundBitcoinAddress = null;
-		Coin bitcoinAmount = null;
-		Address redeemBitcoinAddress = null;
-		byte[] secretHash = null;
-		int lockTime = 0;
-		Coin bitcoinFee = Common.DEFAULT_BTC_FEE;
-
-		int argIndex = 0;
-		try {
-			p2shAddress = Address.fromString(params, args[argIndex++]);
-			if (p2shAddress.getOutputScriptType() != ScriptType.P2SH)
-				usage("P2SH address invalid");
-
-			refundBitcoinAddress = Address.fromString(params, args[argIndex++]);
-			if (refundBitcoinAddress.getOutputScriptType() != ScriptType.P2PKH)
-				usage("Refund BTC address must be in P2PKH form");
-
-			bitcoinAmount = Coin.parseCoin(args[argIndex++]);
-
-			redeemBitcoinAddress = Address.fromString(params, args[argIndex++]);
-			if (redeemBitcoinAddress.getOutputScriptType() != ScriptType.P2PKH)
-				usage("Redeem BTC address must be in P2PKH form");
-
-			secretHash = HashCode.fromString(args[argIndex++]).asBytes();
-			if (secretHash.length != 20)
-				usage("Hash of secret must be 20 bytes");
-
-			lockTime = Integer.parseInt(args[argIndex++]);
-			int refundTimeoutDelay = lockTime - (int) (System.currentTimeMillis() / 1000L);
-			if (refundTimeoutDelay < 600 || refundTimeoutDelay > 7 * 24 * 60 * 60)
-				usage("Locktime (seconds) should be at between 10 minutes and 1 week from now");
-
-			if (args.length > argIndex)
-				bitcoinFee = Coin.parseCoin(args[argIndex++]);
-		} catch (IllegalArgumentException e) {
-			usage(String.format("Invalid argument %d: %s", argIndex, e.getMessage()));
-		}
-
-		try {
-			RepositoryFactory repositoryFactory = new HSQLDBRepositoryFactory(Controller.getRepositoryUrl());
-			RepositoryManager.setRepositoryFactory(repositoryFactory);
-		} catch (DataException e) {
-			throw new RuntimeException("Repository startup issue: " + e.getMessage());
-		}
-
-		try (final Repository repository = RepositoryManager.getRepository()) {
-			System.out.println("Confirm the following is correct based on the info you've given:");
-
-			System.out.println(String.format("Refund Bitcoin address: %s", redeemBitcoinAddress));
-			System.out.println(String.format("Bitcoin redeem amount: %s", bitcoinAmount.toPlainString()));
-
-			System.out.println(String.format("Redeem Bitcoin address: %s", refundBitcoinAddress));
-			System.out.println(String.format("Redeem miner's fee: %s", BTC.format(bitcoinFee)));
-
-			System.out.println(String.format("Redeem script lockTime: %s (%d)", LocalDateTime.ofInstant(Instant.ofEpochSecond(lockTime), ZoneOffset.UTC), lockTime));
-			System.out.println(String.format("Hash of secret: %s", HashCode.fromBytes(secretHash)));
-
-			System.out.println(String.format("P2SH address: %s", p2shAddress));
-
-			byte[] redeemScriptBytes = BTCP2SH.buildScript(refundBitcoinAddress.getHash(), lockTime, redeemBitcoinAddress.getHash(), secretHash);
-			System.out.println(String.format("Redeem script: %s", HashCode.fromBytes(redeemScriptBytes)));
-
-			byte[] redeemScriptHash = Crypto.hash160(redeemScriptBytes);
-			Address derivedP2shAddress = LegacyAddress.fromScriptHash(params, redeemScriptHash);
-
-			if (!derivedP2shAddress.equals(p2shAddress)) {
-				System.err.println(String.format("Derived P2SH address %s does not match given address %s", derivedP2shAddress, p2shAddress));
-				System.exit(2);
-			}
-
-			bitcoinAmount = bitcoinAmount.add(bitcoinFee);
-
-			long medianBlockTime = BTC.getInstance().getMedianBlockTime();
-			System.out.println(String.format("Median block time: %s", LocalDateTime.ofInstant(Instant.ofEpochSecond(medianBlockTime), ZoneOffset.UTC)));
-
-			long now = System.currentTimeMillis();
-
-			if (now < medianBlockTime * 1000L)
-				System.out.println(String.format("Too soon (%s) to redeem based on median block time %s", LocalDateTime.ofInstant(Instant.ofEpochMilli(now), ZoneOffset.UTC), LocalDateTime.ofInstant(Instant.ofEpochSecond(medianBlockTime), ZoneOffset.UTC)));
-
-			// Check P2SH is funded
-			long p2shBalance = BTC.getInstance().getConfirmedBalance(p2shAddress.toString());
-			System.out.println(String.format("P2SH address %s balance: %s", p2shAddress, BTC.format(p2shBalance)));
-
-			// Grab all P2SH funding transactions (just in case there are more than one)
-			List<TransactionOutput> fundingOutputs = BTC.getInstance().getUnspentOutputs(p2shAddress.toString());
-			if (fundingOutputs == null) {
-				System.err.println(String.format("Can't find outputs for P2SH"));
-				System.exit(2);
-			}
-
-			System.out.println(String.format("Found %d output%s for P2SH", fundingOutputs.size(), (fundingOutputs.size() != 1 ? "s" : "")));
-
-			for (TransactionOutput fundingOutput : fundingOutputs)
-				System.out.println(String.format("Output %s:%d amount %s", HashCode.fromBytes(fundingOutput.getParentTransactionHash().getBytes()), fundingOutput.getIndex(), BTC.format(fundingOutput.getValue())));
-
-			if (fundingOutputs.isEmpty()) {
-				System.err.println(String.format("Can't redeem spent/unfunded P2SH"));
-				System.exit(2);
-			}
-
-			if (fundingOutputs.size() != 1) {
-				System.err.println(String.format("Expecting only one unspent output for P2SH"));
-				System.exit(2);
-			}
-		} catch (DataException e) {
-			System.err.println("Repository issue: " + e.getMessage());
-		} catch (BitcoinException e) {
-			System.err.println("Bitcoin issue: " + e.getMessage());
-		}
-	}
-
-}

src/test/java/org/qortal/test/btcacct/Common.java

@@ -1,9 +0,0 @@
-package org.qortal.test.btcacct;
-
-import org.bitcoinj.core.Coin;
-
-public abstract class Common {
-
-	public static final Coin DEFAULT_BTC_FEE = Coin.parseCoin("0.00001000");
-
-}

src/test/java/org/qortal/test/btcacct/P2shTests.java

@@ -1,53 +0,0 @@
-package org.qortal.test.btcacct;
-
-import static org.junit.Assert.*;
-
-import java.util.Arrays;
-import java.util.List;
-
-import org.junit.After;
-import org.junit.Before;
-import org.junit.Test;
-import org.qortal.crosschain.BTC;
-import org.qortal.crosschain.BTCP2SH;
-import org.qortal.crosschain.BitcoinException;
-import org.qortal.repository.DataException;
-import org.qortal.test.common.Common;
-
-public class P2shTests extends Common {
-
-	@Before
-	public void beforeTest() throws DataException {
-		Common.useDefaultSettings(); // TestNet3
-	}
-
-	@After
-	public void afterTest() {
-		BTC.resetForTesting();
-	}
-
-	@Test
-	public void testFindP2shSecret() throws BitcoinException {
-		// This actually exists on TEST3 but can take a while to fetch
-		String p2shAddress = "2N8WCg52ULCtDSMjkgVTm5mtPdCsUptkHWE";
-
-		List<byte[]> rawTransactions = BTC.getInstance().getAddressTransactions(p2shAddress);
-
-		byte[] expectedSecret = "This string is exactly 32 bytes!".getBytes();
-		byte[] secret = BTCP2SH.findP2shSecret(p2shAddress, rawTransactions);
-
-		assertNotNull(secret);
-		assertTrue("secret incorrect", Arrays.equals(expectedSecret, secret));
-	}
-
-	@Test
-	public void testDetermineP2shStatus() throws BitcoinException {
-		// This actually exists on TEST3 but can take a while to fetch
-		String p2shAddress = "2N8WCg52ULCtDSMjkgVTm5mtPdCsUptkHWE";
-
-		BTCP2SH.Status p2shStatus = BTCP2SH.determineP2shStatus(p2shAddress, 1L);
-
-		System.out.println(String.format("P2SH %s status: %s", p2shAddress, p2shStatus.name()));
-	}
-
-}

src/test/java/org/qortal/test/btcacct/Redeem.java

@@ -1,211 +0,0 @@
-package org.qortal.test.btcacct;
-
-import java.security.Security;
-import java.time.Instant;
-import java.time.LocalDateTime;
-import java.time.ZoneOffset;
-import java.util.Arrays;
-import java.util.List;
-
-import org.bitcoinj.core.Address;
-import org.bitcoinj.core.Coin;
-import org.bitcoinj.core.ECKey;
-import org.bitcoinj.core.LegacyAddress;
-import org.bitcoinj.core.NetworkParameters;
-import org.bitcoinj.core.Transaction;
-import org.bitcoinj.core.TransactionOutput;
-import org.bitcoinj.script.Script.ScriptType;
-import org.bouncycastle.jce.provider.BouncyCastleProvider;
-import org.qortal.controller.Controller;
-import org.qortal.crosschain.BTC;
-import org.qortal.crosschain.BTCP2SH;
-import org.qortal.crosschain.BitcoinException;
-import org.qortal.crypto.Crypto;
-import org.qortal.repository.DataException;
-import org.qortal.repository.Repository;
-import org.qortal.repository.RepositoryFactory;
-import org.qortal.repository.RepositoryManager;
-import org.qortal.repository.hsqldb.HSQLDBRepositoryFactory;
-import org.qortal.settings.Settings;
-
-import com.google.common.hash.HashCode;
-
-public class Redeem {
-
-	static {
-		// This must go before any calls to LogManager/Logger
-		System.setProperty("java.util.logging.manager", "org.apache.logging.log4j.jul.LogManager");
-	}
-
-	private static void usage(String error) {
-		if (error != null)
-			System.err.println(error);
-
-		System.err.println(String.format("usage: Redeem <P2SH-address> <refund-BTC-P2PKH> <redeem-BTC-PRIVATE-key> <secret> <locktime> (<BTC-redeem/refund-fee>)"));
-		System.err.println(String.format("example: Redeem "
-				+ "2NEZboTLhBDPPQciR7sExBhy3TsDi7wV3Cv \\\n"
-				+ "\tmrTDPdM15cFWJC4g223BXX5snicfVJBx6M \\\n"
-				+ "\tec199a4abc9d3bf024349e397535dfee9d287e174aeabae94237eb03a0118c03 \\\n"
-				+ "\t5468697320737472696e672069732065786163746c7920333220627974657321 \\\n"
-				+ "\t1585920000"));
-		System.exit(1);
-	}
-
-	public static void main(String[] args) {
-		if (args.length < 5 || args.length > 6)
-			usage(null);
-
-		Security.insertProviderAt(new BouncyCastleProvider(), 0);
-		Settings.fileInstance("settings-test.json");
-
-		BTC btc = BTC.getInstance();
-		NetworkParameters params = btc.getNetworkParameters();
-
-		Address p2shAddress = null;
-		Address refundBitcoinAddress = null;
-		byte[] redeemPrivateKey = null;
-		byte[] secret = null;
-		int lockTime = 0;
-		Coin bitcoinFee = Common.DEFAULT_BTC_FEE;
-
-		int argIndex = 0;
-		try {
-			p2shAddress = Address.fromString(params, args[argIndex++]);
-			if (p2shAddress.getOutputScriptType() != ScriptType.P2SH)
-				usage("P2SH address invalid");
-
-			refundBitcoinAddress = Address.fromString(params, args[argIndex++]);
-			if (refundBitcoinAddress.getOutputScriptType() != ScriptType.P2PKH)
-				usage("Refund BTC address must be in P2PKH form");
-
-			redeemPrivateKey = HashCode.fromString(args[argIndex++]).asBytes();
-			// Auto-trim
-			if (redeemPrivateKey.length >= 37 && redeemPrivateKey.length <= 38)
-				redeemPrivateKey = Arrays.copyOfRange(redeemPrivateKey, 1, 33);
-			if (redeemPrivateKey.length != 32)
-				usage("Redeem private key must be 32 bytes");
-
-			secret = HashCode.fromString(args[argIndex++]).asBytes();
-			if (secret.length == 0)
-				usage("Invalid secret bytes");
-
-			lockTime = Integer.parseInt(args[argIndex++]);
-
-			if (args.length > argIndex)
-				bitcoinFee = Coin.parseCoin(args[argIndex++]);
-		} catch (IllegalArgumentException e) {
-			usage(String.format("Invalid argument %d: %s", argIndex, e.getMessage()));
-		}
-
-		try {
-			RepositoryFactory repositoryFactory = new HSQLDBRepositoryFactory(Controller.getRepositoryUrl());
-			RepositoryManager.setRepositoryFactory(repositoryFactory);
-		} catch (DataException e) {
-			throw new RuntimeException("Repository startup issue: " + e.getMessage());
-		}
-
-		try (final Repository repository = RepositoryManager.getRepository()) {
-			System.out.println("Confirm the following is correct based on the info you've given:");
-
-			System.out.println(String.format("Redeem PRIVATE key: %s", HashCode.fromBytes(redeemPrivateKey)));
-			System.out.println(String.format("Redeem miner's fee: %s", BTC.format(bitcoinFee)));
-			System.out.println(String.format("Redeem script lockTime: %s (%d)", LocalDateTime.ofInstant(Instant.ofEpochSecond(lockTime), ZoneOffset.UTC), lockTime));
-
-			// New/derived info
-
-			byte[] secretHash = Crypto.hash160(secret);
-			System.out.println(String.format("HASH160 of secret: %s", HashCode.fromBytes(secretHash)));
-
-			ECKey redeemKey = ECKey.fromPrivate(redeemPrivateKey);
-			Address redeemAddress = Address.fromKey(params, redeemKey, ScriptType.P2PKH);
-			System.out.println(String.format("Redeem recipient (PKH): %s (%s)", redeemAddress, HashCode.fromBytes(redeemAddress.getHash())));
-
-			System.out.println(String.format("P2SH address: %s", p2shAddress));
-
-			byte[] redeemScriptBytes = BTCP2SH.buildScript(refundBitcoinAddress.getHash(), lockTime, redeemAddress.getHash(), secretHash);
-			System.out.println(String.format("Redeem script: %s", HashCode.fromBytes(redeemScriptBytes)));
-
-			byte[] redeemScriptHash = Crypto.hash160(redeemScriptBytes);
-			Address derivedP2shAddress = LegacyAddress.fromScriptHash(params, redeemScriptHash);
-
-			if (!derivedP2shAddress.equals(p2shAddress)) {
-				System.err.println(String.format("Derived P2SH address %s does not match given address %s", derivedP2shAddress, p2shAddress));
-				System.exit(2);
-			}
-
-			// Some checks
-
-			System.out.println("\nProcessing:");
-
-			long medianBlockTime;
-			try {
-				medianBlockTime = BTC.getInstance().getMedianBlockTime();
-			} catch (BitcoinException e1) {
-				System.err.println("Unable to determine median block time");
-				System.exit(2);
-				return;
-			}
-			System.out.println(String.format("Median block time: %s", LocalDateTime.ofInstant(Instant.ofEpochSecond(medianBlockTime), ZoneOffset.UTC)));
-
-			long now = System.currentTimeMillis();
-
-			if (now < medianBlockTime * 1000L) {
-				System.err.println(String.format("Too soon (%s) to redeem based on median block time %s", LocalDateTime.ofInstant(Instant.ofEpochMilli(now), ZoneOffset.UTC), LocalDateTime.ofInstant(Instant.ofEpochSecond(medianBlockTime), ZoneOffset.UTC)));
-				System.exit(2);
-			}
-
-			// Check P2SH is funded
-			long p2shBalance;
-			try {
-				p2shBalance = BTC.getInstance().getConfirmedBalance(p2shAddress.toString());
-			} catch (BitcoinException e) {
-				System.err.println(String.format("Unable to check P2SH address %s balance", p2shAddress));
-				System.exit(2);
-				return;
-			}
-			System.out.println(String.format("P2SH address %s balance: %s", p2shAddress, BTC.format(p2shBalance)));
-
-			// Grab all P2SH funding transactions (just in case there are more than one)
-			List<TransactionOutput> fundingOutputs;
-			try {
-				fundingOutputs = BTC.getInstance().getUnspentOutputs(p2shAddress.toString());
-			} catch (BitcoinException e) {
-				System.err.println(String.format("Can't find outputs for P2SH"));
-				System.exit(2);
-				return;
-			}
-
-			System.out.println(String.format("Found %d output%s for P2SH", fundingOutputs.size(), (fundingOutputs.size() != 1 ? "s" : "")));
-
-			for (TransactionOutput fundingOutput : fundingOutputs)
-				System.out.println(String.format("Output %s:%d amount %s", HashCode.fromBytes(fundingOutput.getParentTransactionHash().getBytes()), fundingOutput.getIndex(), BTC.format(fundingOutput.getValue())));
-
-			if (fundingOutputs.isEmpty()) {
-				System.err.println(String.format("Can't redeem spent/unfunded P2SH"));
-				System.exit(2);
-			}
-
-			if (fundingOutputs.size() != 1) {
-				System.err.println(String.format("Expecting only one unspent output for P2SH"));
-				// No longer fatal
-			}
-
-			for (TransactionOutput fundingOutput : fundingOutputs)
-				System.out.println(String.format("Using output %s:%d for redeem", HashCode.fromBytes(fundingOutput.getParentTransactionHash().getBytes()), fundingOutput.getIndex()));
-
-			Coin redeemAmount = Coin.valueOf(p2shBalance).subtract(bitcoinFee);
-			System.out.println(String.format("Spending %s of output, with %s as mining fee", BTC.format(redeemAmount), BTC.format(bitcoinFee)));
-
-			Transaction redeemTransaction = BTCP2SH.buildRedeemTransaction(redeemAmount, redeemKey, fundingOutputs, redeemScriptBytes, secret, redeemAddress.getHash());
-
-			byte[] redeemBytes = redeemTransaction.bitcoinSerialize();
-
-			System.out.println(String.format("\nLoad this transaction into your wallet and broadcast:\n%s\n", HashCode.fromBytes(redeemBytes).toString()));
-		} catch (NumberFormatException e) {
-			usage(String.format("Number format exception: %s", e.getMessage()));
-		} catch (DataException e) {
-			throw new RuntimeException("Repository issue: " + e.getMessage());
-		}
-	}
-
-}

src/test/java/org/qortal/test/btcacct/Refund.java

@@ -1,215 +0,0 @@
-package org.qortal.test.btcacct;
-
-import java.security.Security;
-import java.time.Instant;
-import java.time.LocalDateTime;
-import java.time.ZoneOffset;
-import java.util.Arrays;
-import java.util.List;
-
-import org.bitcoinj.core.Address;
-import org.bitcoinj.core.Coin;
-import org.bitcoinj.core.ECKey;
-import org.bitcoinj.core.LegacyAddress;
-import org.bitcoinj.core.NetworkParameters;
-import org.bitcoinj.core.Transaction;
-import org.bitcoinj.core.TransactionOutput;
-import org.bitcoinj.script.Script.ScriptType;
-import org.bouncycastle.jce.provider.BouncyCastleProvider;
-import org.qortal.controller.Controller;
-import org.qortal.crosschain.BTC;
-import org.qortal.crosschain.BTCP2SH;
-import org.qortal.crosschain.BitcoinException;
-import org.qortal.crypto.Crypto;
-import org.qortal.repository.DataException;
-import org.qortal.repository.Repository;
-import org.qortal.repository.RepositoryFactory;
-import org.qortal.repository.RepositoryManager;
-import org.qortal.repository.hsqldb.HSQLDBRepositoryFactory;
-import org.qortal.settings.Settings;
-
-import com.google.common.hash.HashCode;
-
-public class Refund {
-
-	static {
-		// This must go before any calls to LogManager/Logger
-		System.setProperty("java.util.logging.manager", "org.apache.logging.log4j.jul.LogManager");
-	}
-
-	private static void usage(String error) {
-		if (error != null)
-			System.err.println(error);
-
-		System.err.println(String.format("usage: Refund <P2SH-address> <refund-BTC-PRIVATE-KEY> <redeem-BTC-P2PKH> <HASH160-of-secret> <locktime> (<BTC-redeem/refund-fee>)"));
-		System.err.println(String.format("example: Refund "
-				+ "2NEZboTLhBDPPQciR7sExBhy3TsDi7wV3Cv \\\n"
-				+ "\tef027fb5828c5e201eaf6de4cd3b0b340d16a191ef848cd691f35ef8f727358c9c01b576fb7e \\\n"
-				+ "\tn2N5VKrzq39nmuefZwp3wBiF4icdXX2B6o \\\n"
-				+ "\tdaf59884b4d1aec8c1b17102530909ee43c0151a \\\n"
-				+ "\t1585920000"));
-		System.exit(1);
-	}
-
-	public static void main(String[] args) {
-		if (args.length < 5 || args.length > 6)
-			usage(null);
-
-		Security.insertProviderAt(new BouncyCastleProvider(), 0);
-		Settings.fileInstance("settings-test.json");
-
-		BTC btc = BTC.getInstance();
-		NetworkParameters params = btc.getNetworkParameters();
-
-		Address p2shAddress = null;
-		byte[] refundPrivateKey = null;
-		Address redeemBitcoinAddress = null;
-		byte[] secretHash = null;
-		int lockTime = 0;
-		Coin bitcoinFee = Common.DEFAULT_BTC_FEE;
-
-		int argIndex = 0;
-		try {
-			p2shAddress = Address.fromString(params, args[argIndex++]);
-			if (p2shAddress.getOutputScriptType() != ScriptType.P2SH)
-				usage("P2SH address invalid");
-
-			refundPrivateKey = HashCode.fromString(args[argIndex++]).asBytes();
-			// Auto-trim
-			if (refundPrivateKey.length >= 37 && refundPrivateKey.length <= 38)
-				refundPrivateKey = Arrays.copyOfRange(refundPrivateKey, 1, 33);
-			if (refundPrivateKey.length != 32)
-				usage("Refund private key must be 32 bytes");
-
-			redeemBitcoinAddress = Address.fromString(params, args[argIndex++]);
-			if (redeemBitcoinAddress.getOutputScriptType() != ScriptType.P2PKH)
-				usage("Their BTC address must be in P2PKH form");
-
-			secretHash = HashCode.fromString(args[argIndex++]).asBytes();
-			if (secretHash.length != 20)
-				usage("HASH160 of secret must be 20 bytes");
-
-			lockTime = Integer.parseInt(args[argIndex++]);
-
-			if (args.length > argIndex)
-				bitcoinFee = Coin.parseCoin(args[argIndex++]);
-		} catch (IllegalArgumentException e) {
-			usage(String.format("Invalid argument %d: %s", argIndex, e.getMessage()));
-		}
-
-		try {
-			RepositoryFactory repositoryFactory = new HSQLDBRepositoryFactory(Controller.getRepositoryUrl());
-			RepositoryManager.setRepositoryFactory(repositoryFactory);
-		} catch (DataException e) {
-			throw new RuntimeException("Repository startup issue: " + e.getMessage());
-		}
-
-		try (final Repository repository = RepositoryManager.getRepository()) {
-			System.out.println("Confirm the following is correct based on the info you've given:");
-
-			System.out.println(String.format("Refund PRIVATE key: %s", HashCode.fromBytes(refundPrivateKey)));
-			System.out.println(String.format("Redeem Bitcoin address: %s", redeemBitcoinAddress));
-			System.out.println(String.format("Redeem script lockTime: %s (%d)", LocalDateTime.ofInstant(Instant.ofEpochSecond(lockTime), ZoneOffset.UTC), lockTime));
-			System.out.println(String.format("P2SH address: %s", p2shAddress));
-			System.out.println(String.format("Refund miner's fee: %s", BTC.format(bitcoinFee)));
-
-			// New/derived info
-
-			System.out.println("\nCHECKING info from other party:");
-
-			ECKey refundKey = ECKey.fromPrivate(refundPrivateKey);
-			Address refundAddress = Address.fromKey(params, refundKey, ScriptType.P2PKH);
-			System.out.println(String.format("Refund recipient (PKH): %s (%s)", refundAddress, HashCode.fromBytes(refundAddress.getHash())));
-
-			byte[] redeemScriptBytes = BTCP2SH.buildScript(refundAddress.getHash(), lockTime, redeemBitcoinAddress.getHash(), secretHash);
-			System.out.println(String.format("Redeem script: %s", HashCode.fromBytes(redeemScriptBytes)));
-
-			byte[] redeemScriptHash = Crypto.hash160(redeemScriptBytes);
-			Address derivedP2shAddress = LegacyAddress.fromScriptHash(params, redeemScriptHash);
-
-			if (!derivedP2shAddress.equals(p2shAddress)) {
-				System.err.println(String.format("Derived P2SH address %s does not match given address %s", derivedP2shAddress, p2shAddress));
-				System.exit(2);
-			}
-
-			// Some checks
-
-			System.out.println("\nProcessing:");
-
-			long medianBlockTime;
-			try {
-				medianBlockTime = BTC.getInstance().getMedianBlockTime();
-			} catch (BitcoinException e) {
-				System.err.println("Unable to determine median block time");
-				System.exit(2);
-				return;
-			}
-			System.out.println(String.format("Median block time: %s", LocalDateTime.ofInstant(Instant.ofEpochSecond(medianBlockTime), ZoneOffset.UTC)));
-
-			long now = System.currentTimeMillis();
-
-			if (now < medianBlockTime * 1000L) {
-				System.err.println(String.format("Too soon (%s) to refund based on median block time %s", LocalDateTime.ofInstant(Instant.ofEpochMilli(now), ZoneOffset.UTC), LocalDateTime.ofInstant(Instant.ofEpochSecond(medianBlockTime), ZoneOffset.UTC)));
-				System.exit(2);
-			}
-
-			if (now < lockTime * 1000L) {
-				System.err.println(String.format("Too soon (%s) to refund based on lockTime %s", LocalDateTime.ofInstant(Instant.ofEpochMilli(now), ZoneOffset.UTC), LocalDateTime.ofInstant(Instant.ofEpochSecond(lockTime), ZoneOffset.UTC)));
-				System.exit(2);
-			}
-
-			// Check P2SH is funded
-			long p2shBalance;
-			try {
-				p2shBalance = BTC.getInstance().getConfirmedBalance(p2shAddress.toString());
-			} catch (BitcoinException e) {
-				System.err.println(String.format("Unable to check P2SH address %s balance", p2shAddress));
-				System.exit(2);
-				return;
-			}
-			System.out.println(String.format("P2SH address %s balance: %s", p2shAddress, BTC.format(p2shBalance)));
-
-			// Grab all P2SH funding transactions (just in case there are more than one)
-			List<TransactionOutput> fundingOutputs;
-			try {
-				fundingOutputs = BTC.getInstance().getUnspentOutputs(p2shAddress.toString());
-			} catch (BitcoinException e) {
-				System.err.println(String.format("Can't find outputs for P2SH"));
-				System.exit(2);
-				return;
-			}
-
-			System.out.println(String.format("Found %d output%s for P2SH", fundingOutputs.size(), (fundingOutputs.size() != 1 ? "s" : "")));
-
-			for (TransactionOutput fundingOutput : fundingOutputs)
-				System.out.println(String.format("Output %s:%d amount %s", HashCode.fromBytes(fundingOutput.getParentTransactionHash().getBytes()), fundingOutput.getIndex(), BTC.format(fundingOutput.getValue())));
-
-			if (fundingOutputs.isEmpty()) {
-				System.err.println(String.format("Can't refund spent/unfunded P2SH"));
-				System.exit(2);
-			}
-
-			if (fundingOutputs.size() != 1) {
-				System.err.println(String.format("Expecting only one unspent output for P2SH"));
-				// No longer fatal
-			}
-
-			for (TransactionOutput fundingOutput : fundingOutputs)
-				System.out.println(String.format("Using output %s:%d for redeem", HashCode.fromBytes(fundingOutput.getParentTransactionHash().getBytes()), fundingOutput.getIndex()));
-
-			Coin refundAmount = Coin.valueOf(p2shBalance).subtract(bitcoinFee);
-			System.out.println(String.format("Spending %s of output, with %s as mining fee", BTC.format(refundAmount), BTC.format(bitcoinFee)));
-
-			Transaction redeemTransaction = BTCP2SH.buildRefundTransaction(refundAmount, refundKey, fundingOutputs, redeemScriptBytes, lockTime, refundKey.getPubKeyHash());
-
-			byte[] redeemBytes = redeemTransaction.bitcoinSerialize();
-
-			System.out.println(String.format("\nLoad this transaction into your wallet and broadcast:\n%s\n", HashCode.fromBytes(redeemBytes).toString()));
-		} catch (NumberFormatException e) {
-			usage(String.format("Number format exception: %s", e.getMessage()));
-		} catch (DataException e) {
-			throw new RuntimeException("Repository issue: " + e.getMessage());
-		}
-	}
-
-}

src/test/java/org/qortal/test/crosschain/BitcoinTests.java

@@ -1,44 +1,46 @@
-package org.qortal.test.btcacct;
+package org.qortal.test.crosschain;
 
 import static org.junit.Assert.*;
 
 import java.util.Arrays;
-import java.util.List;
 
 import org.bitcoinj.core.Transaction;
 import org.bitcoinj.store.BlockStoreException;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
-import org.qortal.crosschain.BTC;
-import org.qortal.crosschain.BTCP2SH;
-import org.qortal.crosschain.BitcoinException;
+import org.qortal.crosschain.Bitcoin;
+import org.qortal.crosschain.ForeignBlockchainException;
+import org.qortal.crosschain.BitcoinyHTLC;
 import org.qortal.repository.DataException;
 import org.qortal.test.common.Common;
 
-public class BtcTests extends Common {
+public class BitcoinTests extends Common {
+
+	private Bitcoin bitcoin;
 
 	@Before
 	public void beforeTest() throws DataException {
 		Common.useDefaultSettings(); // TestNet3
+		bitcoin = Bitcoin.getInstance();
 	}
 
 	@After
 	public void afterTest() {
-		BTC.resetForTesting();
+		Bitcoin.resetForTesting();
+		bitcoin = null;
 	}
 
 	@Test
-	public void testGetMedianBlockTime() throws BlockStoreException, BitcoinException {
+	public void testGetMedianBlockTime() throws BlockStoreException, ForeignBlockchainException {
 		System.out.println(String.format("Starting BTC instance..."));
-		BTC btc = BTC.getInstance();
 		System.out.println(String.format("BTC instance started"));
 
 		long before = System.currentTimeMillis();
-		System.out.println(String.format("Bitcoin median blocktime: %d", btc.getMedianBlockTime()));
+		System.out.println(String.format("Bitcoin median blocktime: %d", bitcoin.getMedianBlockTime()));
 		long afterFirst = System.currentTimeMillis();
 
-		System.out.println(String.format("Bitcoin median blocktime: %d", btc.getMedianBlockTime()));
+		System.out.println(String.format("Bitcoin median blocktime: %d", bitcoin.getMedianBlockTime()));
 		long afterSecond = System.currentTimeMillis();
 
 		long firstPeriod = afterFirst - before;
@@ -51,14 +53,12 @@ public class BtcTests extends Common {
 	}
 
 	@Test
-	public void testFindP2shSecret() throws BitcoinException {
+	public void testFindHtlcSecret() throws ForeignBlockchainException {
 		// This actually exists on TEST3 but can take a while to fetch
 		String p2shAddress = "2N8WCg52ULCtDSMjkgVTm5mtPdCsUptkHWE";
 
-		List<byte[]> rawTransactions = BTC.getInstance().getAddressTransactions(p2shAddress);
-
 		byte[] expectedSecret = "This string is exactly 32 bytes!".getBytes();
-		byte[] secret = BTCP2SH.findP2shSecret(p2shAddress, rawTransactions);
+		byte[] secret = BitcoinyHTLC.findHtlcSecret(bitcoin, p2shAddress);
 
 		assertNotNull(secret);
 		assertTrue("secret incorrect", Arrays.equals(expectedSecret, secret));
@@ -66,52 +66,46 @@ public class BtcTests extends Common {
 
 	@Test
 	public void testBuildSpend() {
-		BTC btc = BTC.getInstance();
-
 		String xprv58 = "tprv8ZgxMBicQKsPdahhFSrCdvC1bsWyzHHZfTneTVqUXN6s1wEtZLwAkZXzFP6TYLg2aQMecZLXLre5bTVGajEB55L1HYJcawpdFG66STVAWPJ";
 
 		String recipient = "2N8WCg52ULCtDSMjkgVTm5mtPdCsUptkHWE";
 		long amount = 1000L;
 
-		Transaction transaction = btc.buildSpend(xprv58, recipient, amount);
+		Transaction transaction = bitcoin.buildSpend(xprv58, recipient, amount);
 		assertNotNull(transaction);
 
 		// Check spent key caching doesn't affect outcome
 
-		transaction = btc.buildSpend(xprv58, recipient, amount);
+		transaction = bitcoin.buildSpend(xprv58, recipient, amount);
 		assertNotNull(transaction);
 	}
 
 	@Test
 	public void testGetWalletBalance() {
-		BTC btc = BTC.getInstance();
-
 		String xprv58 = "tprv8ZgxMBicQKsPdahhFSrCdvC1bsWyzHHZfTneTVqUXN6s1wEtZLwAkZXzFP6TYLg2aQMecZLXLre5bTVGajEB55L1HYJcawpdFG66STVAWPJ";
 
-		Long balance = btc.getWalletBalance(xprv58);
+		Long balance = bitcoin.getWalletBalance(xprv58);
 
 		assertNotNull(balance);
 
-		System.out.println(BTC.format(balance));
+		System.out.println(bitcoin.format(balance));
 
 		// Check spent key caching doesn't affect outcome
 
-		Long repeatBalance = btc.getWalletBalance(xprv58);
+		Long repeatBalance = bitcoin.getWalletBalance(xprv58);
 
 		assertNotNull(repeatBalance);
 
-		System.out.println(BTC.format(repeatBalance));
+		System.out.println(bitcoin.format(repeatBalance));
 
 		assertEquals(balance, repeatBalance);
 	}
 
 	@Test
-	public void testGetUnusedReceiveAddress() throws BitcoinException {
-		BTC btc = BTC.getInstance();
-
+	public void testGetUnusedReceiveAddress() throws ForeignBlockchainException {
 		String xprv58 = "tprv8ZgxMBicQKsPdahhFSrCdvC1bsWyzHHZfTneTVqUXN6s1wEtZLwAkZXzFP6TYLg2aQMecZLXLre5bTVGajEB55L1HYJcawpdFG66STVAWPJ";
 
-		String address = btc.getUnusedReceiveAddress(xprv58);
+		String address = bitcoin.getUnusedReceiveAddress(xprv58);
 
 		assertNotNull(address);
 

src/test/java/org/qortal/test/crosschain/ElectrumXTests.java

@@ -1,9 +1,11 @@
-package org.qortal.test.btcacct;
+package org.qortal.test.crosschain;
 
 import static org.junit.Assert.*;
 
 import java.security.Security;
+import java.util.EnumMap;
 import java.util.List;
+import java.util.Map;
 
 import org.bitcoinj.core.Address;
 import org.bitcoinj.params.TestNet3Params;
@@ -11,11 +13,13 @@ import org.bitcoinj.script.ScriptBuilder;
 import org.bouncycastle.jce.provider.BouncyCastleProvider;
 import org.bouncycastle.jsse.provider.BouncyCastleJsseProvider;
 import org.junit.Test;
-import org.qortal.crosschain.BitcoinException;
-import org.qortal.crosschain.BitcoinTransaction;
+import org.qortal.crosschain.ForeignBlockchainException;
+import org.qortal.crosschain.BitcoinyTransaction;
 import org.qortal.crosschain.ElectrumX;
 import org.qortal.crosschain.TransactionHash;
 import org.qortal.crosschain.UnspentOutput;
+import org.qortal.crosschain.Bitcoin.BitcoinNet;
+import org.qortal.crosschain.ElectrumX.Server.ConnectionType;
 import org.qortal.utils.BitTwiddling;
 
 import com.google.common.hash.HashCode;
@@ -30,15 +34,25 @@ public class ElectrumXTests {
 		Security.insertProviderAt(new BouncyCastleJsseProvider(), 1);
 	}
 
+	private static final Map<ElectrumX.Server.ConnectionType, Integer> DEFAULT_ELECTRUMX_PORTS = new EnumMap<>(ElectrumX.Server.ConnectionType.class);
+	static {
+		DEFAULT_ELECTRUMX_PORTS.put(ConnectionType.TCP, 50001);
+		DEFAULT_ELECTRUMX_PORTS.put(ConnectionType.SSL, 50002);
+	}
+
+	private ElectrumX getInstance() {
+		return new ElectrumX("Bitcoin-" + BitcoinNet.TEST3.name(), BitcoinNet.TEST3.getGenesisHash(), BitcoinNet.TEST3.getServers(), DEFAULT_ELECTRUMX_PORTS);
+	}
+
 	@Test
 	public void testInstance() {
-		ElectrumX electrumX = ElectrumX.getInstance("TEST3");
+		ElectrumX electrumX = getInstance();
 		assertNotNull(electrumX);
 	}
 
 	@Test
-	public void testGetCurrentHeight() throws BitcoinException {
-		ElectrumX electrumX = ElectrumX.getInstance("TEST3");
+	public void testGetCurrentHeight() throws ForeignBlockchainException {
+		ElectrumX electrumX = getInstance();
 
 		int height = electrumX.getCurrentHeight();
 
@@ -48,10 +62,10 @@ public class ElectrumXTests {
 
 	@Test
 	public void testInvalidRequest() {
-		ElectrumX electrumX = ElectrumX.getInstance("TEST3");
+		ElectrumX electrumX = getInstance();
 		try {
-			electrumX.getBlockHeaders(-1, -1);
-		} catch (BitcoinException e) {
+			electrumX.getRawBlockHeaders(-1, -1);
+		} catch (ForeignBlockchainException e) {
 			// Should throw due to negative start block height
 			return;
 		}
@@ -60,13 +74,13 @@ public class ElectrumXTests {
 	}
 
 	@Test
-	public void testGetRecentBlocks() throws BitcoinException {
-		ElectrumX electrumX = ElectrumX.getInstance("TEST3");
+	public void testGetRecentBlocks() throws ForeignBlockchainException {
+		ElectrumX electrumX = getInstance();
 
 		int height = electrumX.getCurrentHeight();
 		assertTrue(height > 10000);
 
-		List<byte[]> recentBlockHeaders = electrumX.getBlockHeaders(height - 11, 11);
+		List<byte[]> recentBlockHeaders = electrumX.getRawBlockHeaders(height - 11, 11);
 
 		System.out.println(String.format("Returned %d recent blocks", recentBlockHeaders.size()));
 		for (int i = 0; i < recentBlockHeaders.size(); ++i) {
@@ -80,8 +94,8 @@ public class ElectrumXTests {
 	}
 
 	@Test
-	public void testGetP2PKHBalance() throws BitcoinException {
-		ElectrumX electrumX = ElectrumX.getInstance("TEST3");
+	public void testGetP2PKHBalance() throws ForeignBlockchainException {
+		ElectrumX electrumX = getInstance();
 
 		Address address = Address.fromString(TestNet3Params.get(), "n3GNqMveyvaPvUbH469vDRadqpJMPc84JA");
 		byte[] script = ScriptBuilder.createOutputScript(address).getProgram();
@@ -93,8 +107,8 @@ public class ElectrumXTests {
 	}
 
 	@Test
-	public void testGetP2SHBalance() throws BitcoinException {
-		ElectrumX electrumX = ElectrumX.getInstance("TEST3");
+	public void testGetP2SHBalance() throws ForeignBlockchainException {
+		ElectrumX electrumX = getInstance();
 
 		Address address = Address.fromString(TestNet3Params.get(), "2N4szZUfigj7fSBCEX4PaC8TVbC5EvidaVF");
 		byte[] script = ScriptBuilder.createOutputScript(address).getProgram();
@@ -106,8 +120,8 @@ public class ElectrumXTests {
 	}
 
 	@Test
-	public void testGetUnspentOutputs() throws BitcoinException {
-		ElectrumX electrumX = ElectrumX.getInstance("TEST3");
+	public void testGetUnspentOutputs() throws ForeignBlockchainException {
+		ElectrumX electrumX = getInstance();
 
 		Address address = Address.fromString(TestNet3Params.get(), "2N4szZUfigj7fSBCEX4PaC8TVbC5EvidaVF");
 		byte[] script = ScriptBuilder.createOutputScript(address).getProgram();
@@ -120,8 +134,8 @@ public class ElectrumXTests {
 	}
 
 	@Test
-	public void testGetRawTransaction() throws BitcoinException {
-		ElectrumX electrumX = ElectrumX.getInstance("TEST3");
+	public void testGetRawTransaction() throws ForeignBlockchainException {
+		ElectrumX electrumX = getInstance();
 
 		byte[] txHash = HashCode.fromString("7653fea9ffcd829d45ed2672938419a94951b08175982021e77d619b553f29af").asBytes();
 
@@ -132,26 +146,26 @@ public class ElectrumXTests {
 
 	@Test
 	public void testGetUnknownRawTransaction() {
-		ElectrumX electrumX = ElectrumX.getInstance("TEST3");
+		ElectrumX electrumX = getInstance();
 
 		byte[] txHash = HashCode.fromString("f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0").asBytes();
 
 		try {
 			electrumX.getRawTransaction(txHash);
 			fail("Bitcoin transaction should be unknown and hence throw exception");
-		} catch (BitcoinException e) {
-			if (!(e instanceof BitcoinException.NotFoundException))
+		} catch (ForeignBlockchainException e) {
+			if (!(e instanceof ForeignBlockchainException.NotFoundException))
 				fail("Bitcoin transaction should be unknown and hence throw NotFoundException");
 		}
 	}
 
 	@Test
-	public void testGetTransaction() throws BitcoinException {
-		ElectrumX electrumX = ElectrumX.getInstance("TEST3");
+	public void testGetTransaction() throws ForeignBlockchainException {
+		ElectrumX electrumX = getInstance();
 
 		String txHash = "7653fea9ffcd829d45ed2672938419a94951b08175982021e77d619b553f29af";
 
-		BitcoinTransaction transaction = electrumX.getTransaction(txHash);
+		BitcoinyTransaction transaction = electrumX.getTransaction(txHash);
 
 		assertNotNull(transaction);
 		assertTrue(transaction.txHash.equals(txHash));
@@ -159,22 +173,22 @@ public class ElectrumXTests {
 
 	@Test
 	public void testGetUnknownTransaction() {
-		ElectrumX electrumX = ElectrumX.getInstance("TEST3");
+		ElectrumX electrumX = getInstance();
 
 		String txHash = "f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0";
 
 		try {
 			electrumX.getTransaction(txHash);
 			fail("Bitcoin transaction should be unknown and hence throw exception");
-		} catch (BitcoinException e) {
-			if (!(e instanceof BitcoinException.NotFoundException))
+		} catch (ForeignBlockchainException e) {
+			if (!(e instanceof ForeignBlockchainException.NotFoundException))
 				fail("Bitcoin transaction should be unknown and hence throw NotFoundException");
 		}
 	}
 
 	@Test
-	public void testGetAddressTransactions() throws BitcoinException {
-		ElectrumX electrumX = ElectrumX.getInstance("TEST3");
+	public void testGetAddressTransactions() throws ForeignBlockchainException {
+		ElectrumX electrumX = getInstance();
 
 		Address address = Address.fromString(TestNet3Params.get(), "2N8WCg52ULCtDSMjkgVTm5mtPdCsUptkHWE");
 		byte[] script = ScriptBuilder.createOutputScript(address).getProgram();

src/test/java/org/qortal/test/crosschain/HtlcTests.java

@@ -0,0 +1,126 @@
+package org.qortal.test.crosschain;
+
+import static org.junit.Assert.*;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.qortal.crosschain.Bitcoin;
+import org.qortal.crosschain.ForeignBlockchainException;
+import org.qortal.crypto.Crypto;
+import org.qortal.crosschain.BitcoinyHTLC;
+import org.qortal.repository.DataException;
+import org.qortal.test.common.Common;
+
+import com.google.common.primitives.Longs;
+
+public class HtlcTests extends Common {
+
+	private Bitcoin bitcoin;
+
+	@Before
+	public void beforeTest() throws DataException {
+		Common.useDefaultSettings(); // TestNet3
+		bitcoin = Bitcoin.getInstance();
+	}
+
+	@After
+	public void afterTest() {
+		Bitcoin.resetForTesting();
+		bitcoin = null;
+	}
+
+	@Test
+	public void testFindHtlcSecret() throws ForeignBlockchainException {
+		// This actually exists on TEST3 but can take a while to fetch
+		String p2shAddress = "2N8WCg52ULCtDSMjkgVTm5mtPdCsUptkHWE";
+
+		byte[] expectedSecret = "This string is exactly 32 bytes!".getBytes();
+		byte[] secret = BitcoinyHTLC.findHtlcSecret(bitcoin, p2shAddress);
+
+		assertNotNull(secret);
+		assertArrayEquals("secret incorrect", expectedSecret, secret);
+	}
+
+	@Test
+	public void testHtlcSecretCaching() throws ForeignBlockchainException {
+		String p2shAddress = "2N8WCg52ULCtDSMjkgVTm5mtPdCsUptkHWE";
+		byte[] expectedSecret = "This string is exactly 32 bytes!".getBytes();
+
+		do {
+			// We need to perform fresh setup for 1st test
+			Bitcoin.resetForTesting();
+			bitcoin = Bitcoin.getInstance();
+
+			long now = System.currentTimeMillis();
+			long timestampBoundary = now / 30_000L;
+
+			byte[] secret1 = BitcoinyHTLC.findHtlcSecret(bitcoin, p2shAddress);
+			long executionPeriod1 = System.currentTimeMillis() - now;
+
+			assertNotNull(secret1);
+			assertArrayEquals("secret1 incorrect", expectedSecret, secret1);
+
+			assertTrue("1st execution period should not be instant!", executionPeriod1 > 10);
+
+			byte[] secret2 = BitcoinyHTLC.findHtlcSecret(bitcoin, p2shAddress);
+			long executionPeriod2 = System.currentTimeMillis() - now - executionPeriod1;
+
+			assertNotNull(secret2);
+			assertArrayEquals("secret2 incorrect", expectedSecret, secret2);
+
+			// Test is only valid if we've called within same timestampBoundary
+			if (System.currentTimeMillis() / 30_000L != timestampBoundary)
+				continue;
+
+			assertArrayEquals(secret1, secret2);
+
+			assertTrue("2st execution period should be effectively instant!", executionPeriod2 < 10);
+		} while (false);
+	}
+
+	@Test
+	public void testDetermineHtlcStatus() throws ForeignBlockchainException {
+		// This actually exists on TEST3 but can take a while to fetch
+		String p2shAddress = "2N8WCg52ULCtDSMjkgVTm5mtPdCsUptkHWE";
+
+		BitcoinyHTLC.Status htlcStatus = BitcoinyHTLC.determineHtlcStatus(bitcoin.getBlockchainProvider(), p2shAddress, 1L);
+		assertNotNull(htlcStatus);
+
+		System.out.println(String.format("HTLC %s status: %s", p2shAddress, htlcStatus.name()));
+	}
+
+	@Test
+	public void testHtlcStatusCaching() throws ForeignBlockchainException {
+		do {
+			// We need to perform fresh setup for 1st test
+			Bitcoin.resetForTesting();
+			bitcoin = Bitcoin.getInstance();
+
+			long now = System.currentTimeMillis();
+			long timestampBoundary = now / 30_000L;
+
+			// Won't ever exist
+			String p2shAddress = bitcoin.deriveP2shAddress(Crypto.hash160(Longs.toByteArray(now)));
+
+			BitcoinyHTLC.Status htlcStatus1 = BitcoinyHTLC.determineHtlcStatus(bitcoin.getBlockchainProvider(), p2shAddress, 1L);
+			long executionPeriod1 = System.currentTimeMillis() - now;
+
+			assertNotNull(htlcStatus1);
+			assertTrue("1st execution period should not be instant!", executionPeriod1 > 10);
+
+			BitcoinyHTLC.Status htlcStatus2 = BitcoinyHTLC.determineHtlcStatus(bitcoin.getBlockchainProvider(), p2shAddress, 1L);
+			long executionPeriod2 = System.currentTimeMillis() - now - executionPeriod1;
+
+			assertNotNull(htlcStatus2);
+			assertEquals(htlcStatus1, htlcStatus2);
+
+			// Test is only valid if we've called within same timestampBoundary
+			if (System.currentTimeMillis() / 30_000L != timestampBoundary)
+				continue;
+
+			assertTrue("2st execution period should be effectively instant!", executionPeriod2 < 10);
+		} while (false);
+	}
+
+}

src/test/java/org/qortal/test/crosschain/LitecoinTests.java

@@ -0,0 +1,112 @@
+package org.qortal.test.crosschain;
+
+import static org.junit.Assert.*;
+
+import java.util.Arrays;
+
+import org.bitcoinj.core.Transaction;
+import org.bitcoinj.store.BlockStoreException;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.qortal.crosschain.ForeignBlockchainException;
+import org.qortal.crosschain.Litecoin;
+import org.qortal.crosschain.BitcoinyHTLC;
+import org.qortal.repository.DataException;
+import org.qortal.test.common.Common;
+
+public class LitecoinTests extends Common {
+
+	private Litecoin litecoin;
+
+	@Before
+	public void beforeTest() throws DataException {
+		Common.useDefaultSettings(); // TestNet3
+		litecoin = Litecoin.getInstance();
+	}
+
+	@After
+	public void afterTest() {
+		Litecoin.resetForTesting();
+		litecoin = null;
+	}
+
+	@Test
+	public void testGetMedianBlockTime() throws BlockStoreException, ForeignBlockchainException {
+		long before = System.currentTimeMillis();
+		System.out.println(String.format("Bitcoin median blocktime: %d", litecoin.getMedianBlockTime()));
+		long afterFirst = System.currentTimeMillis();
+
+		System.out.println(String.format("Bitcoin median blocktime: %d", litecoin.getMedianBlockTime()));
+		long afterSecond = System.currentTimeMillis();
+
+		long firstPeriod = afterFirst - before;
+		long secondPeriod = afterSecond - afterFirst;
+
+		System.out.println(String.format("1st call: %d ms, 2nd call: %d ms", firstPeriod, secondPeriod));
+
+		assertTrue("2nd call should be quicker than 1st", secondPeriod < firstPeriod);
+		assertTrue("2nd call should take less than 5 seconds", secondPeriod < 5000L);
+	}
+
+	@Test
+	public void testFindHtlcSecret() throws ForeignBlockchainException {
+		// This actually exists on TEST3 but can take a while to fetch
+		String p2shAddress = "2N8WCg52ULCtDSMjkgVTm5mtPdCsUptkHWE";
+
+		byte[] expectedSecret = "This string is exactly 32 bytes!".getBytes();
+		byte[] secret = BitcoinyHTLC.findHtlcSecret(litecoin, p2shAddress);
+
+		assertNotNull("secret not found", secret);
+		assertTrue("secret incorrect", Arrays.equals(expectedSecret, secret));
+	}
+
+	@Test
+	public void testBuildSpend() {
+		String xprv58 = "tprv8ZgxMBicQKsPdahhFSrCdvC1bsWyzHHZfTneTVqUXN6s1wEtZLwAkZXzFP6TYLg2aQMecZLXLre5bTVGajEB55L1HYJcawpdFG66STVAWPJ";
+
+		String recipient = "2N8WCg52ULCtDSMjkgVTm5mtPdCsUptkHWE";
+		long amount = 1000L;
+
+		Transaction transaction = litecoin.buildSpend(xprv58, recipient, amount);
+		assertNotNull("insufficient funds", transaction);
+
+		// Check spent key caching doesn't affect outcome
+
+		transaction = litecoin.buildSpend(xprv58, recipient, amount);
+		assertNotNull("insufficient funds", transaction);
+	}
+
+	@Test
+	public void testGetWalletBalance() {
+		String xprv58 = "tprv8ZgxMBicQKsPdahhFSrCdvC1bsWyzHHZfTneTVqUXN6s1wEtZLwAkZXzFP6TYLg2aQMecZLXLre5bTVGajEB55L1HYJcawpdFG66STVAWPJ";
+
+		Long balance = litecoin.getWalletBalance(xprv58);
+
+		assertNotNull(balance);
+
+		System.out.println(litecoin.format(balance));
+
+		// Check spent key caching doesn't affect outcome
+
+		Long repeatBalance = litecoin.getWalletBalance(xprv58);
+
+		assertNotNull(repeatBalance);
+
+		System.out.println(litecoin.format(repeatBalance));
+
+		assertEquals(balance, repeatBalance);
+	}
+
+	@Test
+	public void testGetUnusedReceiveAddress() throws ForeignBlockchainException {
+		String xprv58 = "tprv8ZgxMBicQKsPdahhFSrCdvC1bsWyzHHZfTneTVqUXN6s1wEtZLwAkZXzFP6TYLg2aQMecZLXLre5bTVGajEB55L1HYJcawpdFG66STVAWPJ";
+
+		String address = litecoin.getUnusedReceiveAddress(xprv58);
+
+		assertNotNull(address);
+
+		System.out.println(address);
+	}
+
+}

src/test/java/org/qortal/test/crosschain/apps/BuildHTLC.java

@@ -0,0 +1,114 @@
+package org.qortal.test.crosschain.apps;
+
+import java.time.Instant;
+import java.time.LocalDateTime;
+import java.time.ZoneOffset;
+
+import org.bitcoinj.core.Address;
+import org.bitcoinj.core.Coin;
+import org.bitcoinj.core.NetworkParameters;
+import org.bitcoinj.script.Script.ScriptType;
+import org.qortal.crosschain.Litecoin;
+import org.qortal.crosschain.Bitcoin;
+import org.qortal.crosschain.Bitcoiny;
+import org.qortal.crosschain.BitcoinyHTLC;
+
+import com.google.common.hash.HashCode;
+
+public class BuildHTLC {
+
+	private static void usage(String error) {
+		if (error != null)
+			System.err.println(error);
+
+		System.err.println(String.format("usage: BuildHTLC (-b | -l) <refund-P2PKH> <amount> <redeem-P2PKH> <HASH160-of-secret> <locktime>"));
+		System.err.println("where: -b means use Bitcoin, -l means use Litecoin");
+		System.err.println(String.format("example: BuildHTLC -l "
+				+ "msAfaDaJ8JiprxxFaAXEEPxKK3JaZCYpLv \\\n"
+				+ "\t0.00008642 \\\n"
+				+ "\tmrBpZYYGYMwUa8tRjTiXfP1ySqNXszWN5h \\\n"
+				+ "\tdaf59884b4d1aec8c1b17102530909ee43c0151a \\\n"
+				+ "\t1600000000"));
+		System.exit(1);
+	}
+
+	public static void main(String[] args) {
+		if (args.length < 6 || args.length > 6)
+			usage(null);
+
+		Common.init();
+
+		Bitcoiny bitcoiny = null;
+		NetworkParameters params = null;
+
+		Address refundAddress = null;
+		Coin amount = null;
+		Address redeemAddress = null;
+		byte[] hashOfSecret = null;
+		int lockTime = 0;
+
+		int argIndex = 0;
+		try {
+			switch (args[argIndex++]) {
+				case "-b":
+					bitcoiny = Bitcoin.getInstance();
+					break;
+
+				case "-l":
+					bitcoiny = Litecoin.getInstance();
+					break;
+
+				default:
+					usage("Only Bitcoin (-b) or Litecoin (-l) supported");
+			}
+			params = bitcoiny.getNetworkParameters();
+
+			refundAddress = Address.fromString(params, args[argIndex++]);
+			if (refundAddress.getOutputScriptType() != ScriptType.P2PKH)
+				usage("Refund address must be in P2PKH form");
+
+			amount = Coin.parseCoin(args[argIndex++]);
+
+			redeemAddress = Address.fromString(params, args[argIndex++]);
+			if (redeemAddress.getOutputScriptType() != ScriptType.P2PKH)
+				usage("Redeem address must be in P2PKH form");
+
+			hashOfSecret = HashCode.fromString(args[argIndex++]).asBytes();
+			if (hashOfSecret.length != 20)
+				usage("Hash of secret must be 20 bytes");
+
+			lockTime = Integer.parseInt(args[argIndex++]);
+			int refundTimeoutDelay = lockTime - (int) (System.currentTimeMillis() / 1000L);
+			if (refundTimeoutDelay < 600 || refundTimeoutDelay > 30 * 24 * 60 * 60)
+				usage("Locktime (seconds) should be at between 10 minutes and 1 month from now");
+		} catch (IllegalArgumentException e) {
+			usage(String.format("Invalid argument %d: %s", argIndex, e.getMessage()));
+		}
+
+		System.out.println(String.format("Using %s", bitcoiny.getBlockchainProvider().getNetId()));
+
+		Coin p2shFee = Coin.valueOf(Common.getP2shFee(bitcoiny));
+		if (p2shFee.isZero())
+			return;
+
+		System.out.println(String.format("Refund address: %s", refundAddress));
+		System.out.println(String.format("Amount: %s", amount.toPlainString()));
+		System.out.println(String.format("Redeem address: %s", redeemAddress));
+		System.out.println(String.format("Refund/redeem miner's fee: %s", bitcoiny.format(p2shFee)));
+		System.out.println(String.format("Script lockTime: %s (%d)", LocalDateTime.ofInstant(Instant.ofEpochSecond(lockTime), ZoneOffset.UTC), lockTime));
+		System.out.println(String.format("Hash of secret: %s", HashCode.fromBytes(hashOfSecret)));
+
+		byte[] redeemScriptBytes = BitcoinyHTLC.buildScript(refundAddress.getHash(), lockTime, redeemAddress.getHash(), hashOfSecret);
+		System.out.println(String.format("Raw script bytes: %s", HashCode.fromBytes(redeemScriptBytes)));
+
+		String p2shAddress = bitcoiny.deriveP2shAddress(redeemScriptBytes);
+		System.out.println(String.format("P2SH address: %s", p2shAddress));
+
+		amount = amount.add(p2shFee);
+
+		// Fund P2SH
+		System.out.println(String.format("\nYou need to fund %s with %s (includes redeem/refund fee of %s)",
+				p2shAddress, bitcoiny.format(amount), bitcoiny.format(p2shFee)));
+	}
+
+}

src/test/java/org/qortal/test/crosschain/apps/CheckHTLC.java

@@ -0,0 +1,135 @@
+package org.qortal.test.crosschain.apps;
+
+import java.time.Instant;
+import java.time.LocalDateTime;
+import java.time.ZoneOffset;
+
+import org.bitcoinj.core.Address;
+import org.bitcoinj.core.Coin;
+import org.bitcoinj.core.LegacyAddress;
+import org.bitcoinj.core.NetworkParameters;
+import org.bitcoinj.script.Script.ScriptType;
+import org.qortal.crosschain.Bitcoin;
+import org.qortal.crosschain.Bitcoiny;
+import org.qortal.crosschain.Litecoin;
+import org.qortal.crosschain.BitcoinyHTLC;
+import org.qortal.crypto.Crypto;
+
+import com.google.common.hash.HashCode;
+
+public class CheckHTLC {
+
+	private static void usage(String error) {
+		if (error != null)
+			System.err.println(error);
+
+		System.err.println(String.format("usage: CheckHTLC (-b | -l) <P2SH-address> <refund-P2PKH> <amount> <redeem-P2PKH> <HASH160-of-secret> <locktime>"));
+		System.err.println("where: -b means use Bitcoin, -l means use Litecoin");
+		System.err.println(String.format("example: CheckP2SH -l "
+				+ "2N4378NbEVGjmiUmoUD9g1vCY6kyx9tDUJ6 \\\n"
+				+ "msAfaDaJ8JiprxxFaAXEEPxKK3JaZCYpLv \\\n"
+				+ "\t0.00008642 \\\n"
+				+ "\tmrBpZYYGYMwUa8tRjTiXfP1ySqNXszWN5h \\\n"
+				+ "\tdaf59884b4d1aec8c1b17102530909ee43c0151a \\\n"
+				+ "\t1600184800"));
+		System.exit(1);
+	}
+
+	public static void main(String[] args) {
+		if (args.length < 7 || args.length > 7)
+			usage(null);
+
+		Common.init();
+
+		Bitcoiny bitcoiny = null;
+		NetworkParameters params = null;
+
+		Address p2shAddress = null;
+		Address refundAddress = null;
+		Coin amount = null;
+		Address redeemAddress = null;
+		byte[] hashOfSecret = null;
+		int lockTime = 0;
+
+		int argIndex = 0;
+		try {
+			switch (args[argIndex++]) {
+				case "-b":
+					bitcoiny = Bitcoin.getInstance();
+					break;
+
+				case "-l":
+					bitcoiny = Litecoin.getInstance();
+					break;
+
+				default:
+					usage("Only Bitcoin (-b) or Litecoin (-l) supported");
+			}
+			params = bitcoiny.getNetworkParameters();
+
+			p2shAddress = Address.fromString(params, args[argIndex++]);
+			if (p2shAddress.getOutputScriptType() != ScriptType.P2SH)
+				usage("P2SH address invalid");
+
+			refundAddress = Address.fromString(params, args[argIndex++]);
+			if (refundAddress.getOutputScriptType() != ScriptType.P2PKH)
+				usage("Refund address must be in P2PKH form");
+
+			amount = Coin.parseCoin(args[argIndex++]);
+
+			redeemAddress = Address.fromString(params, args[argIndex++]);
+			if (redeemAddress.getOutputScriptType() != ScriptType.P2PKH)
+				usage("Redeem address must be in P2PKH form");
+
+			hashOfSecret = HashCode.fromString(args[argIndex++]).asBytes();
+			if (hashOfSecret.length != 20)
+				usage("Hash of secret must be 20 bytes");
+
+			lockTime = Integer.parseInt(args[argIndex++]);
+		} catch (IllegalArgumentException e) {
+			usage(String.format("Invalid argument %d: %s", argIndex, e.getMessage()));
+		}
+
+		System.out.println(String.format("Using %s", bitcoiny.getBlockchainProvider().getNetId()));
+
+		Coin p2shFee = Coin.valueOf(Common.getP2shFee(bitcoiny));
+		if (p2shFee.isZero())
+			return;
+
+		System.out.println(String.format("P2SH address: %s", p2shAddress));
+		System.out.println(String.format("Refund PKH: %s", refundAddress));
+		System.out.println(String.format("Redeem/refund amount: %s", amount.toPlainString()));
+		System.out.println(String.format("Redeem PKH: %s", redeemAddress));
+		System.out.println(String.format("Hash of secret: %s", HashCode.fromBytes(hashOfSecret)));
+		System.out.println(String.format("Script lockTime: %s (%d)", LocalDateTime.ofInstant(Instant.ofEpochSecond(lockTime), ZoneOffset.UTC), lockTime));
+
+		System.out.println(String.format("Redeem/refund miner's fee: %s", bitcoiny.format(p2shFee)));
+
+		byte[] redeemScriptBytes = BitcoinyHTLC.buildScript(refundAddress.getHash(), lockTime, redeemAddress.getHash(), hashOfSecret);
+		System.out.println(String.format("Raw script bytes: %s", HashCode.fromBytes(redeemScriptBytes)));
+
+		byte[] redeemScriptHash = Crypto.hash160(redeemScriptBytes);
+		Address derivedP2shAddress = LegacyAddress.fromScriptHash(params, redeemScriptHash);
+
+		if (!derivedP2shAddress.equals(p2shAddress)) {
+			System.err.println(String.format("Derived P2SH address %s does not match given address %s", derivedP2shAddress, p2shAddress));
+			System.exit(2);
+		}
+
+		amount = amount.add(p2shFee);
+
+		// Check network's median block time
+		int medianBlockTime = Common.checkMedianBlockTime(bitcoiny, null);
+		if (medianBlockTime == 0)
+			return;
+
+		// Check P2SH is funded
+		Common.getBalance(bitcoiny, p2shAddress.toString());
+
+		// Grab all unspent outputs
+		Common.getUnspentOutputs(bitcoiny, p2shAddress.toString());
+
+		Common.determineHtlcStatus(bitcoiny, p2shAddress.toString(), amount.value);
+	}
+
+}

src/test/java/org/qortal/test/crosschain/apps/Common.java

@@ -0,0 +1,158 @@
+package org.qortal.test.crosschain.apps;
+
+import java.security.Security;
+import java.time.Instant;
+import java.time.LocalDateTime;
+import java.time.ZoneOffset;
+import java.util.Collections;
+import java.util.List;
+
+import org.bitcoinj.core.Transaction;
+import org.bitcoinj.core.TransactionOutput;
+import org.bouncycastle.jce.provider.BouncyCastleProvider;
+import org.bouncycastle.jsse.provider.BouncyCastleJsseProvider;
+import org.qortal.crosschain.Bitcoiny;
+import org.qortal.crosschain.BitcoinyHTLC;
+import org.qortal.crosschain.ForeignBlockchainException;
+import org.qortal.settings.Settings;
+import org.qortal.utils.NTP;
+
+import com.google.common.hash.HashCode;
+
+public abstract class Common {
+
+	public static void init() {
+		Security.insertProviderAt(new BouncyCastleProvider(), 0);
+		Security.insertProviderAt(new BouncyCastleJsseProvider(), 1);
+
+		Settings.fileInstance("settings-test.json");
+
+		NTP.setFixedOffset(0L);
+	}
+
+	public static long getP2shFee(Bitcoiny bitcoiny) {
+		long p2shFee;
+
+		try {
+			p2shFee = bitcoiny.getP2shFee(null);
+		} catch (ForeignBlockchainException e) {
+			System.err.println(String.format("Unable to determine P2SH fee: %s", e.getMessage()));
+			return 0;
+		}
+
+		return p2shFee;
+	}
+
+	public static int checkMedianBlockTime(Bitcoiny bitcoiny, Integer lockTime) {
+		int medianBlockTime;
+
+		try {
+			medianBlockTime = bitcoiny.getMedianBlockTime();
+		} catch (ForeignBlockchainException e) {
+			System.err.println(String.format("Unable to determine median block time: %s", e.getMessage()));
+			return 0;
+		}
+
+		System.out.println(String.format("Median block time: %s", LocalDateTime.ofInstant(Instant.ofEpochSecond(medianBlockTime), ZoneOffset.UTC)));
+
+		long now = System.currentTimeMillis();
+
+		if (now < medianBlockTime * 1000L) {
+			System.out.println(String.format("Too soon (%s) based on median block time %s",
+					LocalDateTime.ofInstant(Instant.ofEpochMilli(now), ZoneOffset.UTC),
+					LocalDateTime.ofInstant(Instant.ofEpochSecond(medianBlockTime), ZoneOffset.UTC)));
+			return 0;
+		}
+
+		if (lockTime != null && now < lockTime * 1000L) {
+			System.err.println(String.format("Too soon (%s) based on lockTime %s",
+					LocalDateTime.ofInstant(Instant.ofEpochMilli(now), ZoneOffset.UTC),
+					LocalDateTime.ofInstant(Instant.ofEpochSecond(lockTime), ZoneOffset.UTC)));
+			return 0;
+		}
+
+		return medianBlockTime;
+	}
+
+	public static long getBalance(Bitcoiny bitcoiny, String address58) {
+		long balance;
+
+		try {
+			balance = bitcoiny.getConfirmedBalance(address58);
+		} catch (ForeignBlockchainException e) {
+			System.err.println(String.format("Unable to check address %s balance: %s", address58, e.getMessage()));
+			return 0;
+		}
+
+		System.out.println(String.format("Address %s balance: %s", address58, bitcoiny.format(balance)));
+
+		return balance;
+	}
+
+	public static List<TransactionOutput> getUnspentOutputs(Bitcoiny bitcoiny, String address58) {
+		List<TransactionOutput> unspentOutputs = Collections.emptyList();
+
+		try {
+			unspentOutputs = bitcoiny.getUnspentOutputs(address58);
+		} catch (ForeignBlockchainException e) {
+			System.err.println(String.format("Can't find unspent outputs for %s: %s", address58, e.getMessage()));
+			return unspentOutputs;
+		}
+
+		System.out.println(String.format("Found %d output%s for %s",
+				unspentOutputs.size(),
+				(unspentOutputs.size() != 1 ? "s" : ""),
+				address58));
+
+		for (TransactionOutput fundingOutput : unspentOutputs)
+			System.out.println(String.format("Output %s:%d amount %s",
+					HashCode.fromBytes(fundingOutput.getParentTransactionHash().getBytes()), fundingOutput.getIndex(),
+					bitcoiny.format(fundingOutput.getValue())));
+
+		if (unspentOutputs.isEmpty())
+			System.err.println(String.format("Can't use spent/unfunded %s", address58));
+
+		if (unspentOutputs.size() != 1)
+			System.err.println(String.format("Expecting only one unspent output?"));
+
+		return unspentOutputs;
+	}
+
+	public static BitcoinyHTLC.Status determineHtlcStatus(Bitcoiny bitcoiny, String address58, long minimumAmount) {
+		BitcoinyHTLC.Status htlcStatus = null;
+
+		try {
+			htlcStatus = BitcoinyHTLC.determineHtlcStatus(bitcoiny.getBlockchainProvider(), address58, minimumAmount);
+
+			System.out.println(String.format("HTLC status: %s", htlcStatus.name()));
+		} catch (ForeignBlockchainException e) {
+			System.err.println(String.format("Unable to determine HTLC status: %s", e.getMessage()));
+		}
+
+		return htlcStatus;
+	}
+
+	public static void broadcastTransaction(Bitcoiny bitcoiny, Transaction transaction) {
+		byte[] rawTransactionBytes = transaction.bitcoinSerialize();
+
+		System.out.println(String.format("%nRaw transaction bytes:%n%s%n", HashCode.fromBytes(rawTransactionBytes).toString()));
+
+		for (int countDown = 5; countDown >= 1; --countDown) {
+			System.out.print(String.format("\rBroadcasting transaction in %d second%s... use CTRL-C to abort ", countDown, (countDown != 1 ? "s" : "")));
+			try {
+				Thread.sleep(1000L);
+			} catch (InterruptedException e) {
+				System.exit(0);
+			}
+		}
+		System.out.println("Broadcasting transaction...                                    ");
+
+		try {
+			bitcoiny.broadcastTransaction(transaction);
+		} catch (ForeignBlockchainException e) {
+			System.err.println(String.format("Failed to broadcast transaction: %s", e.getMessage()));
+			System.exit(1);
+		}
+	}
+
+}

src/test/java/org/qortal/test/crosschain/apps/GetNextReceiveAddress.java

@@ -0,0 +1,78 @@
+package org.qortal.test.crosschain.apps;
+
+import java.security.Security;
+
+import org.bitcoinj.core.AddressFormatException;
+import org.bouncycastle.jce.provider.BouncyCastleProvider;
+import org.bouncycastle.jsse.provider.BouncyCastleJsseProvider;
+import org.qortal.crosschain.Bitcoin;
+import org.qortal.crosschain.Bitcoiny;
+import org.qortal.crosschain.ForeignBlockchainException;
+import org.qortal.crosschain.Litecoin;
+import org.qortal.settings.Settings;
+
+public class GetNextReceiveAddress {
+
+	static {
+		// This must go before any calls to LogManager/Logger
+		System.setProperty("java.util.logging.manager", "org.apache.logging.log4j.jul.LogManager");
+	}
+
+	private static void usage(String error) {
+		if (error != null)
+			System.err.println(error);
+
+		System.err.println(String.format("usage: GetNextReceiveAddress (-b | -l) <xprv/xpub>"));
+		System.err.println(String.format("example (testnet): GetNextReceiveAddress -l tpubD6NzVbkrYhZ4X3jV96Wo3Kr8Au2v9cUUEmPRk1smwduFrRVfBjkkw49rRYjgff1fGSktFMfabbvv8b1dmfyLjjbDax6QGyxpsNsx5PXukCB"));
+		System.exit(1);
+	}
+
+	public static void main(String[] args) {
+		if (args.length != 2)
+			usage(null);
+
+		Security.insertProviderAt(new BouncyCastleProvider(), 0);
+		Security.insertProviderAt(new BouncyCastleJsseProvider(), 1);
+
+		Settings.fileInstance("settings-test.json");
+
+		Bitcoiny bitcoiny = null;
+		String key58 = null;
+
+		int argIndex = 0;
+		try {
+			switch (args[argIndex++]) {
+				case "-b":
+					bitcoiny = Bitcoin.getInstance();
+					break;
+
+				case "-l":
+					bitcoiny = Litecoin.getInstance();
+					break;
+
+				default:
+					usage("Only Bitcoin (-b) or Litecoin (-l) supported");
+			}
+
+			key58 = args[argIndex++];
+
+			if (!bitcoiny.isValidDeterministicKey(key58))
+				usage("Not valid xprv/xpub/tprv/tpub");
+		} catch (NumberFormatException | AddressFormatException e) {
+			usage(String.format("Argument format exception: %s", e.getMessage()));
+		}
+
+		System.out.println(String.format("Using %s", bitcoiny.getBlockchainProvider().getNetId()));
+
+		String receiveAddress = null;
+		try {
+			receiveAddress = bitcoiny.getUnusedReceiveAddress(key58);
+		} catch (ForeignBlockchainException e) {
+			System.err.println(String.format("Failed to determine next receive address: %s", e.getMessage()));
+			System.exit(1);
+		}
+
+		System.out.println(String.format("Next receive address: %s", receiveAddress));
+	}
+
+}

src/test/java/org/qortal/test/crosschain/apps/GetTransaction.java

@@ -1,4 +1,4 @@
-package org.qortal.test.btcacct;
+package org.qortal.test.crosschain.apps;
 
 import java.security.Security;
 import java.util.List;
@@ -6,8 +6,11 @@ import java.util.List;
 import org.bitcoinj.core.AddressFormatException;
 import org.bitcoinj.core.TransactionOutput;
 import org.bouncycastle.jce.provider.BouncyCastleProvider;
-import org.qortal.crosschain.BTC;
-import org.qortal.crosschain.BitcoinException;
+import org.bouncycastle.jsse.provider.BouncyCastleJsseProvider;
+import org.qortal.crosschain.Bitcoin;
+import org.qortal.crosschain.Bitcoiny;
+import org.qortal.crosschain.ForeignBlockchainException;
+import org.qortal.crosschain.Litecoin;
 import org.qortal.settings.Settings;
 
 import com.google.common.hash.HashCode;
@@ -23,34 +26,51 @@ public class GetTransaction {
 		if (error != null)
 			System.err.println(error);
 
-		System.err.println(String.format("usage: GetTransaction <bitcoin-tx>"));
-		System.err.println(String.format("example (mainnet): GetTransaction 816407e79568f165f13e09e9912c5f2243e0a23a007cec425acedc2e89284660"));
-		System.err.println(String.format("example (testnet): GetTransaction 3bfd17a492a4e3d6cb7204e17e20aca6c1ab82e1828bd1106eefbaf086fb8a4e"));
+		System.err.println(String.format("usage: GetTransaction (-b | -l) <tx-hash>"));
+		System.err.println(String.format("example (mainnet): GetTransaction -b 816407e79568f165f13e09e9912c5f2243e0a23a007cec425acedc2e89284660"));
+		System.err.println(String.format("example (testnet): GetTransaction -b 3bfd17a492a4e3d6cb7204e17e20aca6c1ab82e1828bd1106eefbaf086fb8a4e"));
 		System.exit(1);
 	}
 
 	public static void main(String[] args) {
-		if (args.length != 1)
+		if (args.length != 2)
 			usage(null);
 
 		Security.insertProviderAt(new BouncyCastleProvider(), 0);
+		Security.insertProviderAt(new BouncyCastleJsseProvider(), 1);
+
 		Settings.fileInstance("settings-test.json");
 
+		Bitcoiny bitcoiny = null;
 		byte[] transactionId = null;
 
+		int argIndex = 0;
 		try {
-			int argIndex = 0;
+			switch (args[argIndex++]) {
+				case "-b":
+					bitcoiny = Bitcoin.getInstance();
+					break;
+
+				case "-l":
+					bitcoiny = Litecoin.getInstance();
+					break;
+
+				default:
+					usage("Only Bitcoin (-b) or Litecoin (-l) supported");
+			}
 
 			transactionId = HashCode.fromString(args[argIndex++]).asBytes();
 		} catch (NumberFormatException | AddressFormatException e) {
 			usage(String.format("Argument format exception: %s", e.getMessage()));
 		}
 
+		System.out.println(String.format("Using %s", bitcoiny.getBlockchainProvider().getNetId()));
+
 		// Grab all outputs from transaction
 		List<TransactionOutput> fundingOutputs;
 		try {
-			fundingOutputs = BTC.getInstance().getOutputs(transactionId);
-		} catch (BitcoinException e) {
+			fundingOutputs = bitcoiny.getOutputs(transactionId);
+		} catch (ForeignBlockchainException e) {
 			System.out.println(String.format("Transaction not found (or error occurred)"));
 			return;
 		}

src/test/java/org/qortal/test/crosschain/apps/GetWalletTransactions.java

@@ -0,0 +1,86 @@
+package org.qortal.test.crosschain.apps;
+
+import java.security.Security;
+import java.util.Comparator;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import org.bitcoinj.core.AddressFormatException;
+import org.bouncycastle.jce.provider.BouncyCastleProvider;
+import org.bouncycastle.jsse.provider.BouncyCastleJsseProvider;
+import org.qortal.crosschain.Bitcoin;
+import org.qortal.crosschain.Bitcoiny;
+import org.qortal.crosschain.BitcoinyTransaction;
+import org.qortal.crosschain.ForeignBlockchainException;
+import org.qortal.crosschain.Litecoin;
+import org.qortal.settings.Settings;
+
+public class GetWalletTransactions {
+
+	static {
+		// This must go before any calls to LogManager/Logger
+		System.setProperty("java.util.logging.manager", "org.apache.logging.log4j.jul.LogManager");
+	}
+
+	private static void usage(String error) {
+		if (error != null)
+			System.err.println(error);
+
+		System.err.println(String.format("usage: GetWalletTransactions (-b | -l) <xprv/xpub>"));
+		System.err.println(String.format("example (testnet): GetWalletTransactions -l tpubD6NzVbkrYhZ4X3jV96Wo3Kr8Au2v9cUUEmPRk1smwduFrRVfBjkkw49rRYjgff1fGSktFMfabbvv8b1dmfyLjjbDax6QGyxpsNsx5PXukCB"));
+		System.exit(1);
+	}
+
+	public static void main(String[] args) {
+		if (args.length != 2)
+			usage(null);
+
+		Security.insertProviderAt(new BouncyCastleProvider(), 0);
+		Security.insertProviderAt(new BouncyCastleJsseProvider(), 1);
+
+		Settings.fileInstance("settings-test.json");
+
+		Bitcoiny bitcoiny = null;
+		String key58 = null;
+
+		int argIndex = 0;
+		try {
+			switch (args[argIndex++]) {
+				case "-b":
+					bitcoiny = Bitcoin.getInstance();
+					break;
+
+				case "-l":
+					bitcoiny = Litecoin.getInstance();
+					break;
+
+				default:
+					usage("Only Bitcoin (-b) or Litecoin (-l) supported");
+			}
+
+			key58 = args[argIndex++];
+
+			if (!bitcoiny.isValidDeterministicKey(key58))
+				usage("Not valid xprv/xpub/tprv/tpub");
+		} catch (NumberFormatException | AddressFormatException e) {
+			usage(String.format("Argument format exception: %s", e.getMessage()));
+		}
+
+		System.out.println(String.format("Using %s", bitcoiny.getBlockchainProvider().getNetId()));
+
+		// Grab all outputs from transaction
+		List<BitcoinyTransaction> transactions = null;
+		try {
+			transactions = bitcoiny.getWalletTransactions(key58);
+		} catch (ForeignBlockchainException e) {
+			System.err.println(String.format("Failed to obtain wallet transactions: %s", e.getMessage()));
+			System.exit(1);
+		}
+
+		System.out.println(String.format("Found %d transaction%s", transactions.size(), (transactions.size() != 1 ? "s" : "")));
+
+		for (BitcoinyTransaction transaction : transactions.stream().sorted(Comparator.comparingInt(t -> t.timestamp)).collect(Collectors.toList()))
+			System.out.println(String.format("%s", transaction));
+	}
+
+}

src/test/java/org/qortal/test/crosschain/apps/Pay.java

@@ -0,0 +1,80 @@
+package org.qortal.test.crosschain.apps;
+
+import org.bitcoinj.core.Address;
+import org.bitcoinj.core.Coin;
+import org.bitcoinj.core.NetworkParameters;
+import org.bitcoinj.core.Transaction;
+import org.qortal.crosschain.Bitcoin;
+import org.qortal.crosschain.Bitcoiny;
+import org.qortal.crosschain.Litecoin;
+
+public class Pay {
+
+	private static void usage(String error) {
+		if (error != null)
+			System.err.println(error);
+
+		System.err.println(String.format("usage: Pay (-b | -l) <xprv58> <recipient> <LTC-amount>"));
+		System.err.println("where: -b means use Bitcoin, -l means use Litecoin");
+		System.err.println(String.format("example: Pay -l "
+				+ "tprv8ZgxMBicQKsPdahhFSrCdvC1bsWyzHHZfTneTVqUXN6s1wEtZLwAkZXzFP6TYLg2aQMecZLXLre5bTVGajEB55L1HYJcawpdFG66STVAWPJ \\\n"
+				+ "\tmsAfaDaJ8JiprxxFaAXEEPxKK3JaZCYpLv \\\n"
+				+ "\t0.00008642"));
+		System.exit(1);
+	}
+
+	public static void main(String[] args) {
+		if (args.length < 4 || args.length > 4)
+			usage(null);
+
+		Common.init();
+
+		Bitcoiny bitcoiny = null;
+		NetworkParameters params = null;
+
+		String xprv58 = null;
+		Address address = null;
+		Coin amount = null;
+
+		int argIndex = 0;
+		try {
+			switch (args[argIndex++]) {
+				case "-b":
+					bitcoiny = Bitcoin.getInstance();
+					break;
+
+				case "-l":
+					bitcoiny = Litecoin.getInstance();
+					break;
+
+				default:
+					usage("Only Bitcoin (-b) or Litecoin (-l) supported");
+			}
+			params = bitcoiny.getNetworkParameters();
+
+			xprv58 = args[argIndex++];
+			if (!bitcoiny.isValidDeterministicKey(xprv58))
+				usage("xprv invalid");
+
+			address = Address.fromString(params, args[argIndex++]);
+
+			amount = Coin.parseCoin(args[argIndex++]);
+		} catch (IllegalArgumentException e) {
+			usage(String.format("Invalid argument %d: %s", argIndex, e.getMessage()));
+		}
+
+		System.out.println(String.format("Using %s", bitcoiny.getBlockchainProvider().getNetId()));
+
+		System.out.println(String.format("Address: %s", address));
+		System.out.println(String.format("Amount: %s", amount.toPlainString()));
+
+		Transaction transaction = bitcoiny.buildSpend(xprv58, address.toString(), amount.value);
+		if (transaction == null) {
+			System.err.println("Insufficent funds");
+			System.exit(1);
+		}
+
+		Common.broadcastTransaction(bitcoiny, transaction);
+	}
+
+}

src/test/java/org/qortal/test/crosschain/apps/RedeemHTLC.java

@@ -0,0 +1,166 @@
+package org.qortal.test.crosschain.apps;
+
+import java.util.Arrays;
+import java.util.List;
+
+import org.bitcoinj.core.Address;
+import org.bitcoinj.core.Coin;
+import org.bitcoinj.core.ECKey;
+import org.bitcoinj.core.LegacyAddress;
+import org.bitcoinj.core.NetworkParameters;
+import org.bitcoinj.core.Transaction;
+import org.bitcoinj.core.TransactionOutput;
+import org.bitcoinj.script.Script.ScriptType;
+import org.qortal.crosschain.Bitcoin;
+import org.qortal.crosschain.Bitcoiny;
+import org.qortal.crosschain.Litecoin;
+import org.qortal.crosschain.BitcoinyHTLC;
+import org.qortal.crypto.Crypto;
+
+import com.google.common.hash.HashCode;
+
+public class RedeemHTLC {
+
+	static {
+		// This must go before any calls to LogManager/Logger
+		System.setProperty("java.util.logging.manager", "org.apache.logging.log4j.jul.LogManager");
+	}
+
+	private static void usage(String error) {
+		if (error != null)
+			System.err.println(error);
+
+		System.err.println(String.format("usage: Redeem (-b | -l) <P2SH-address> <refund-P2PKH> <redeem-PRIVATE-key> <secret> <locktime> <output-address>"));
+		System.err.println("where: -b means use Bitcoin, -l means use Litecoin");
+		System.err.println(String.format("example: Redeem -l "
+				+ "2N4378NbEVGjmiUmoUD9g1vCY6kyx9tDUJ6 \\\n"
+				+ "\tmsAfaDaJ8JiprxxFaAXEEPxKK3JaZCYpLv \\\n"
+				+ "\tefdaed23c4bc85c8ccae40d774af3c2a10391c648b6420cdd83cd44c27fcb5955201c64e372d \\\n"
+				+ "\t5468697320737472696e672069732065786163746c7920333220627974657321 \\\n"
+				+ "\t1600184800 \\\n"
+				+ "\tmrBpZYYGYMwUa8tRjTiXfP1ySqNXszWN5h"));
+		System.exit(1);
+	}
+
+	public static void main(String[] args) {
+		if (args.length < 7 || args.length > 7)
+			usage(null);
+
+		Common.init();
+
+		Bitcoiny bitcoiny = null;
+		NetworkParameters params = null;
+
+		Address p2shAddress = null;
+		Address refundAddress = null;
+		byte[] redeemPrivateKey = null;
+		byte[] secret = null;
+		int lockTime = 0;
+		Address outputAddress = null;
+
+		int argIndex = 0;
+		try {
+			switch (args[argIndex++]) {
+				case "-b":
+					bitcoiny = Bitcoin.getInstance();
+					break;
+
+				case "-l":
+					bitcoiny = Litecoin.getInstance();
+					break;
+
+				default:
+					usage("Only Bitcoin (-b) or Litecoin (-l) supported");
+			}
+			params = bitcoiny.getNetworkParameters();
+
+			p2shAddress = Address.fromString(params, args[argIndex++]);
+			if (p2shAddress.getOutputScriptType() != ScriptType.P2SH)
+				usage("P2SH address invalid");
+
+			refundAddress = Address.fromString(params, args[argIndex++]);
+			if (refundAddress.getOutputScriptType() != ScriptType.P2PKH)
+				usage("Refund address must be in P2PKH form");
+
+			redeemPrivateKey = HashCode.fromString(args[argIndex++]).asBytes();
+			// Auto-trim
+			if (redeemPrivateKey.length >= 37 && redeemPrivateKey.length <= 38)
+				redeemPrivateKey = Arrays.copyOfRange(redeemPrivateKey, 1, 33);
+			if (redeemPrivateKey.length != 32)
+				usage("Redeem private key must be 32 bytes");
+
+			secret = HashCode.fromString(args[argIndex++]).asBytes();
+			if (secret.length == 0)
+				usage("Invalid secret bytes");
+
+			lockTime = Integer.parseInt(args[argIndex++]);
+
+			outputAddress = Address.fromString(params, args[argIndex++]);
+			if (outputAddress.getOutputScriptType() != ScriptType.P2PKH)
+				usage("Output address invalid");
+		} catch (IllegalArgumentException e) {
+			usage(String.format("Invalid argument %d: %s", argIndex, e.getMessage()));
+		}
+
+		System.out.println(String.format("Using %s", bitcoiny.getBlockchainProvider().getNetId()));
+
+		Coin p2shFee = Coin.valueOf(Common.getP2shFee(bitcoiny));
+		if (p2shFee.isZero())
+			return;
+
+		System.out.println(String.format("Attempting to redeem HTLC %s to %s", p2shAddress, outputAddress));
+
+		byte[] hashOfSecret = Crypto.hash160(secret);
+
+		ECKey redeemKey = ECKey.fromPrivate(redeemPrivateKey);
+		Address redeemAddress = Address.fromKey(params, redeemKey, ScriptType.P2PKH);
+
+		byte[] redeemScriptBytes = BitcoinyHTLC.buildScript(refundAddress.getHash(), lockTime, redeemAddress.getHash(), hashOfSecret);
+
+		byte[] redeemScriptHash = Crypto.hash160(redeemScriptBytes);
+		Address derivedP2shAddress = LegacyAddress.fromScriptHash(params, redeemScriptHash);
+
+		if (!derivedP2shAddress.equals(p2shAddress)) {
+			System.err.println(String.format("Raw script bytes: %s", HashCode.fromBytes(redeemScriptBytes)));
+			System.err.println(String.format("Derived P2SH address %s does not match given address %s", derivedP2shAddress, p2shAddress));
+			System.exit(2);
+			return;
+		}
+
+		// Actual live processing...
+
+		int medianBlockTime = Common.checkMedianBlockTime(bitcoiny, null);
+		if (medianBlockTime == 0)
+			return;
+
+		// Check P2SH is funded
+		long p2shBalance = Common.getBalance(bitcoiny, p2shAddress.toString());
+		if (p2shBalance == 0)
+			return;
+
+		// Grab all unspent outputs
+		List<TransactionOutput> unspentOutputs = Common.getUnspentOutputs(bitcoiny, p2shAddress.toString());
+		if (unspentOutputs.isEmpty())
+			return;
+
+		Coin redeemAmount = Coin.valueOf(p2shBalance).subtract(p2shFee);
+
+		BitcoinyHTLC.Status htlcStatus = Common.determineHtlcStatus(bitcoiny, p2shAddress.toString(), redeemAmount.value);
+		if (htlcStatus == null)
+			return;
+
+		if (htlcStatus != BitcoinyHTLC.Status.FUNDED) {
+			System.err.println(String.format("Expecting %s HTLC status, but actual status is %s", "FUNDED", htlcStatus.name()));
+			System.exit(2);
+			return;
+		}
+
+		System.out.println(String.format("Spending %s of outputs, with %s as mining fee", bitcoiny.format(redeemAmount), bitcoiny.format(p2shFee)));
+
+		Transaction redeemTransaction = BitcoinyHTLC.buildRedeemTransaction(bitcoiny.getNetworkParameters(), redeemAmount, redeemKey,
+				unspentOutputs, redeemScriptBytes, secret, outputAddress.getHash());
+
+		Common.broadcastTransaction(bitcoiny, redeemTransaction);
+	}
+
+}

src/test/java/org/qortal/test/crosschain/apps/RefundHTLC.java

@@ -0,0 +1,163 @@
+package org.qortal.test.crosschain.apps;
+
+import java.util.Arrays;
+import java.util.List;
+
+import org.bitcoinj.core.Address;
+import org.bitcoinj.core.Coin;
+import org.bitcoinj.core.ECKey;
+import org.bitcoinj.core.LegacyAddress;
+import org.bitcoinj.core.NetworkParameters;
+import org.bitcoinj.core.Transaction;
+import org.bitcoinj.core.TransactionOutput;
+import org.bitcoinj.script.Script.ScriptType;
+import org.qortal.crosschain.Litecoin;
+import org.qortal.crosschain.Bitcoin;
+import org.qortal.crosschain.Bitcoiny;
+import org.qortal.crosschain.BitcoinyHTLC;
+import org.qortal.crypto.Crypto;
+
+import com.google.common.hash.HashCode;
+
+public class RefundHTLC {
+
+	static {
+		// This must go before any calls to LogManager/Logger
+		System.setProperty("java.util.logging.manager", "org.apache.logging.log4j.jul.LogManager");
+	}
+
+	private static void usage(String error) {
+		if (error != null)
+			System.err.println(error);
+
+		System.err.println(String.format("usage: RefundHTLC (-b | -l) <P2SH-address> <refund-PRIVATE-KEY> <redeem-P2PKH> <HASH160-of-secret> <locktime> <output-address>"));
+		System.err.println("where: -b means use Bitcoin, -l means use Litecoin");
+		System.err.println(String.format("example: RefundHTLC -l "
+				+ "2N4378NbEVGjmiUmoUD9g1vCY6kyx9tDUJ6 \\\n"
+				+ "\tef8f31b49c31b4a140aebcd9605fded88cc2dad0844c4b984f9191a5a416f72d3801e16447b0 \\\n"
+				+ "\tmrBpZYYGYMwUa8tRjTiXfP1ySqNXszWN5h \\\n"
+				+ "\tdaf59884b4d1aec8c1b17102530909ee43c0151a \\\n"
+				+ "\t1600184800 \\\n"
+				+ "\tmoJtbbhs7T4Z5hmBH2iyKhGrCWBzQWS2CL"));
+		System.exit(1);
+	}
+
+	public static void main(String[] args) {
+		if (args.length < 7 || args.length > 7)
+			usage(null);
+
+		Common.init();
+
+		Bitcoiny bitcoiny = null;
+		NetworkParameters params = null;
+
+		Address p2shAddress = null;
+		byte[] refundPrivateKey = null;
+		Address redeemAddress = null;
+		byte[] hashOfSecret = null;
+		int lockTime = 0;
+		Address outputAddress = null;
+
+		int argIndex = 0;
+		try {
+			switch (args[argIndex++]) {
+				case "-b":
+					bitcoiny = Bitcoin.getInstance();
+					break;
+
+				case "-l":
+					bitcoiny = Litecoin.getInstance();
+					break;
+
+				default:
+					usage("Only Bitcoin (-b) or Litecoin (-l) supported");
+			}
+			params = bitcoiny.getNetworkParameters();
+
+			p2shAddress = Address.fromString(params, args[argIndex++]);
+			if (p2shAddress.getOutputScriptType() != ScriptType.P2SH)
+				usage("P2SH address invalid");
+
+			refundPrivateKey = HashCode.fromString(args[argIndex++]).asBytes();
+			// Auto-trim
+			if (refundPrivateKey.length >= 37 && refundPrivateKey.length <= 38)
+				refundPrivateKey = Arrays.copyOfRange(refundPrivateKey, 1, 33);
+			if (refundPrivateKey.length != 32)
+				usage("Refund private key must be 32 bytes");
+
+			redeemAddress = Address.fromString(params, args[argIndex++]);
+			if (redeemAddress.getOutputScriptType() != ScriptType.P2PKH)
+				usage("Redeem address must be in P2PKH form");
+
+			hashOfSecret = HashCode.fromString(args[argIndex++]).asBytes();
+			if (hashOfSecret.length != 20)
+				usage("HASH160 of secret must be 20 bytes");
+
+			lockTime = Integer.parseInt(args[argIndex++]);
+
+			outputAddress = Address.fromString(params, args[argIndex++]);
+			if (outputAddress.getOutputScriptType() != ScriptType.P2PKH)
+				usage("Output address invalid");
+		} catch (IllegalArgumentException e) {
+			usage(String.format("Invalid argument %d: %s", argIndex, e.getMessage()));
+		}
+
+		System.out.println(String.format("Using %s", bitcoiny.getBlockchainProvider().getNetId()));
+
+		Coin p2shFee = Coin.valueOf(Common.getP2shFee(bitcoiny));
+		if (p2shFee.isZero())
+			return;
+
+		System.out.println(String.format("Attempting to refund HTLC %s to %s", p2shAddress, outputAddress));
+
+		ECKey refundKey = ECKey.fromPrivate(refundPrivateKey);
+		Address refundAddress = Address.fromKey(params, refundKey, ScriptType.P2PKH);
+
+		byte[] redeemScriptBytes = BitcoinyHTLC.buildScript(refundAddress.getHash(), lockTime, redeemAddress.getHash(), hashOfSecret);
+
+		byte[] redeemScriptHash = Crypto.hash160(redeemScriptBytes);
+		Address derivedP2shAddress = LegacyAddress.fromScriptHash(params, redeemScriptHash);
+
+		if (!derivedP2shAddress.equals(p2shAddress)) {
+			System.err.println(String.format("Raw script bytes: %s", HashCode.fromBytes(redeemScriptBytes)));
+			System.err.println(String.format("Derived P2SH address %s does not match given address %s", derivedP2shAddress, p2shAddress));
+			System.exit(2);
+		}
+
+		// Actual live processing...
+
+		int medianBlockTime = Common.checkMedianBlockTime(bitcoiny, lockTime);
+		if (medianBlockTime == 0)
+			return;
+
+		// Check P2SH is funded
+		long p2shBalance = Common.getBalance(bitcoiny, p2shAddress.toString());
+		if (p2shBalance == 0)
+			return;
+
+		// Grab all unspent outputs
+		List<TransactionOutput> unspentOutputs = Common.getUnspentOutputs(bitcoiny, p2shAddress.toString());
+		if (unspentOutputs.isEmpty())
+			return;
+
+		Coin refundAmount = Coin.valueOf(p2shBalance).subtract(p2shFee);
+
+		BitcoinyHTLC.Status htlcStatus = Common.determineHtlcStatus(bitcoiny, p2shAddress.toString(), refundAmount.value);
+		if (htlcStatus == null)
+			return;
+
+		if (htlcStatus != BitcoinyHTLC.Status.FUNDED) {
+			System.err.println(String.format("Expecting %s HTLC status, but actual status is %s", "FUNDED", htlcStatus.name()));
+			System.exit(2);
+			return;
+		}
+
+		System.out.println(String.format("Spending %s of outputs, with %s as mining fee", bitcoiny.format(refundAmount), bitcoiny.format(p2shFee)));
+
+		Transaction refundTransaction = BitcoinyHTLC.buildRefundTransaction(bitcoiny.getNetworkParameters(), refundAmount, refundKey,
+				unspentOutputs, redeemScriptBytes, lockTime, outputAddress.getHash());
+
+		Common.broadcastTransaction(bitcoiny, refundTransaction);
+	}
+
+}

src/test/java/org/qortal/test/crosschain/bitcoinv1/BitcoinACCTv1Tests.java

@@ -1,4 +1,4 @@
-package org.qortal.test.btcacct;
+package org.qortal.test.crosschain.bitcoinv1;
 
 import static org.junit.Assert.*;
 
@@ -18,7 +18,8 @@ import org.qortal.account.Account;
 import org.qortal.account.PrivateKeyAccount;
 import org.qortal.asset.Asset;
 import org.qortal.block.Block;
-import org.qortal.crosschain.BTCACCT;
+import org.qortal.crosschain.BitcoinACCTv1;
+import org.qortal.crosschain.AcctMode;
 import org.qortal.crypto.Crypto;
 import org.qortal.data.at.ATData;
 import org.qortal.data.at.ATStateData;
@@ -41,7 +42,7 @@ import org.qortal.utils.Amounts;
 import com.google.common.hash.HashCode;
 import com.google.common.primitives.Bytes;
 
-public class AtTests extends Common {
+public class BitcoinACCTv1Tests extends Common {
 
 	public static final byte[] secretA = "This string is exactly 32 bytes!".getBytes();
 	public static final byte[] hashOfSecretA = Crypto.hash160(secretA); // daf59884b4d1aec8c1b17102530909ee43c0151a
@@ -51,7 +52,7 @@ public class AtTests extends Common {
 	public static final int tradeTimeout = 20; // blocks
 	public static final long redeemAmount = 80_40200000L;
 	public static final long fundingAmount = 123_45600000L;
-	public static final long bitcoinAmount = 864200L;
+	public static final long bitcoinAmount = 864200L; // 0.00864200 BTC
 
 	private static final Random RANDOM = new Random();
 
@@ -64,8 +65,10 @@ public class AtTests extends Common {
 	public void testCompile() {
 		PrivateKeyAccount tradeAccount = createTradeAccount(null);
 
-		byte[] creationBytes = BTCACCT.buildQortalAT(tradeAccount.getAddress(), bitcoinPublicKeyHash, hashOfSecretB, redeemAmount, bitcoinAmount, tradeTimeout);
-		System.out.println("CIYAM AT creation bytes: " + HashCode.fromBytes(creationBytes).toString());
+		byte[] creationBytes = BitcoinACCTv1.buildQortalAT(tradeAccount.getAddress(), bitcoinPublicKeyHash, hashOfSecretB, redeemAmount, bitcoinAmount, tradeTimeout);
+		assertNotNull(creationBytes);
+
+		System.out.println("AT creation bytes: " + HashCode.fromBytes(creationBytes).toString());
 	}
 
 	@Test
@@ -136,7 +139,7 @@ public class AtTests extends Common {
 			long deployersPostDeploymentBalance = deployersInitialBalance - fundingAmount - deployAtFee;
 
 			// Send creator's address to AT, instead of typical partner's address
-			byte[] messageData = BTCACCT.buildCancelMessage(deployer.getAddress());
+			byte[] messageData = BitcoinACCTv1.getInstance().buildCancelMessage(deployer.getAddress());
 			MessageTransaction messageTransaction = sendMessage(repository, deployer, messageData, atAddress);
 			long messageFee = messageTransaction.getTransactionData().getFee();
 
@@ -150,8 +153,8 @@ public class AtTests extends Common {
 			assertTrue(atData.getIsFinished());
 
 			// AT should be in CANCELLED mode
-			CrossChainTradeData tradeData = BTCACCT.populateTradeData(repository, atData);
-			assertEquals(BTCACCT.Mode.CANCELLED, tradeData.mode);
+			CrossChainTradeData tradeData = BitcoinACCTv1.getInstance().populateTradeData(repository, atData);
+			assertEquals(AcctMode.CANCELLED, tradeData.mode);
 
 			// Check balances
 			long expectedMinimumBalance = deployersPostDeploymentBalance;
@@ -209,8 +212,8 @@ public class AtTests extends Common {
 			assertTrue(atData.getIsFinished());
 
 			// AT should be in CANCELLED mode
-			CrossChainTradeData tradeData = BTCACCT.populateTradeData(repository, atData);
-			assertEquals(BTCACCT.Mode.CANCELLED, tradeData.mode);
+			CrossChainTradeData tradeData = BitcoinACCTv1.getInstance().populateTradeData(repository, atData);
+			assertEquals(AcctMode.CANCELLED, tradeData.mode);
 		}
 	}
 
@@ -232,10 +235,10 @@ public class AtTests extends Common {
 
 			long partnersOfferMessageTransactionTimestamp = System.currentTimeMillis();
 			int lockTimeA = calcTestLockTimeA(partnersOfferMessageTransactionTimestamp);
-			int lockTimeB = BTCACCT.calcLockTimeB(partnersOfferMessageTransactionTimestamp, lockTimeA);
+			int lockTimeB = BitcoinACCTv1.calcLockTimeB(partnersOfferMessageTransactionTimestamp, lockTimeA);
 
 			// Send trade info to AT
-			byte[] messageData = BTCACCT.buildTradeMessage(partner.getAddress(), bitcoinPublicKeyHash, hashOfSecretA, lockTimeA, lockTimeB);
+			byte[] messageData = BitcoinACCTv1.buildTradeMessage(partner.getAddress(), bitcoinPublicKeyHash, hashOfSecretA, lockTimeA, lockTimeB);
 			MessageTransaction messageTransaction = sendMessage(repository, tradeAccount, messageData, atAddress);
 
 			Block postDeploymentBlock = BlockUtils.mintBlock(repository);
@@ -247,10 +250,10 @@ public class AtTests extends Common {
 			describeAt(repository, atAddress);
 
 			ATData atData = repository.getATRepository().fromATAddress(atAddress);
-			CrossChainTradeData tradeData = BTCACCT.populateTradeData(repository, atData);
+			CrossChainTradeData tradeData = BitcoinACCTv1.getInstance().populateTradeData(repository, atData);
 
 			// AT should be in TRADE mode
-			assertEquals(BTCACCT.Mode.TRADING, tradeData.mode);
+			assertEquals(AcctMode.TRADING, tradeData.mode);
 
 			// Check hashOfSecretA was extracted correctly
 			assertTrue(Arrays.equals(hashOfSecretA, tradeData.hashOfSecretA));
@@ -259,7 +262,7 @@ public class AtTests extends Common {
 			assertEquals(partner.getAddress(), tradeData.qortalPartnerAddress);
 
 			// Check trade partner's Bitcoin PKH was extracted correctly
-			assertTrue(Arrays.equals(bitcoinPublicKeyHash, tradeData.partnerBitcoinPKH));
+			assertTrue(Arrays.equals(bitcoinPublicKeyHash, tradeData.partnerForeignPKH));
 
 			// Test orphaning
 			BlockUtils.orphanToBlock(repository, postDeploymentBlockHeight);
@@ -293,10 +296,10 @@ public class AtTests extends Common {
 
 			long partnersOfferMessageTransactionTimestamp = System.currentTimeMillis();
 			int lockTimeA = calcTestLockTimeA(partnersOfferMessageTransactionTimestamp);
-			int lockTimeB = BTCACCT.calcLockTimeB(partnersOfferMessageTransactionTimestamp, lockTimeA);
+			int lockTimeB = BitcoinACCTv1.calcLockTimeB(partnersOfferMessageTransactionTimestamp, lockTimeA);
 
 			// Send trade info to AT BUT NOT FROM AT CREATOR
-			byte[] messageData = BTCACCT.buildTradeMessage(partner.getAddress(), bitcoinPublicKeyHash, hashOfSecretA, lockTimeA, lockTimeB);
+			byte[] messageData = BitcoinACCTv1.buildTradeMessage(partner.getAddress(), bitcoinPublicKeyHash, hashOfSecretA, lockTimeA, lockTimeB);
 			MessageTransaction messageTransaction = sendMessage(repository, bystander, messageData, atAddress);
 
 			BlockUtils.mintBlock(repository);
@@ -309,10 +312,10 @@ public class AtTests extends Common {
 			describeAt(repository, atAddress);
 
 			ATData atData = repository.getATRepository().fromATAddress(atAddress);
-			CrossChainTradeData tradeData = BTCACCT.populateTradeData(repository, atData);
+			CrossChainTradeData tradeData = BitcoinACCTv1.getInstance().populateTradeData(repository, atData);
 
 			// AT should still be in OFFER mode
-			assertEquals(BTCACCT.Mode.OFFERING, tradeData.mode);
+			assertEquals(AcctMode.OFFERING, tradeData.mode);
 		}
 	}
 
@@ -334,10 +337,10 @@ public class AtTests extends Common {
 
 			long partnersOfferMessageTransactionTimestamp = System.currentTimeMillis();
 			int lockTimeA = calcTestLockTimeA(partnersOfferMessageTransactionTimestamp);
-			int lockTimeB = BTCACCT.calcLockTimeB(partnersOfferMessageTransactionTimestamp, lockTimeA);
+			int lockTimeB = BitcoinACCTv1.calcLockTimeB(partnersOfferMessageTransactionTimestamp, lockTimeA);
 
 			// Send trade info to AT
-			byte[] messageData = BTCACCT.buildTradeMessage(partner.getAddress(), bitcoinPublicKeyHash, hashOfSecretA, lockTimeA, lockTimeB);
+			byte[] messageData = BitcoinACCTv1.buildTradeMessage(partner.getAddress(), bitcoinPublicKeyHash, hashOfSecretA, lockTimeA, lockTimeB);
 			MessageTransaction messageTransaction = sendMessage(repository, tradeAccount, messageData, atAddress);
 
 			Block postDeploymentBlock = BlockUtils.mintBlock(repository);
@@ -356,8 +359,8 @@ public class AtTests extends Common {
 			assertTrue(atData.getIsFinished());
 
 			// AT should be in REFUNDED mode
-			CrossChainTradeData tradeData = BTCACCT.populateTradeData(repository, atData);
-			assertEquals(BTCACCT.Mode.REFUNDED, tradeData.mode);
+			CrossChainTradeData tradeData = BitcoinACCTv1.getInstance().populateTradeData(repository, atData);
+			assertEquals(AcctMode.REFUNDED, tradeData.mode);
 
 			// Test orphaning
 			BlockUtils.orphanToBlock(repository, postDeploymentBlockHeight);
@@ -388,17 +391,17 @@ public class AtTests extends Common {
 
 			long partnersOfferMessageTransactionTimestamp = System.currentTimeMillis();
 			int lockTimeA = calcTestLockTimeA(partnersOfferMessageTransactionTimestamp);
-			int lockTimeB = BTCACCT.calcLockTimeB(partnersOfferMessageTransactionTimestamp, lockTimeA);
+			int lockTimeB = BitcoinACCTv1.calcLockTimeB(partnersOfferMessageTransactionTimestamp, lockTimeA);
 
 			// Send trade info to AT
-			byte[] messageData = BTCACCT.buildTradeMessage(partner.getAddress(), bitcoinPublicKeyHash, hashOfSecretA, lockTimeA, lockTimeB);
+			byte[] messageData = BitcoinACCTv1.buildTradeMessage(partner.getAddress(), bitcoinPublicKeyHash, hashOfSecretA, lockTimeA, lockTimeB);
 			MessageTransaction messageTransaction = sendMessage(repository, tradeAccount, messageData, atAddress);
 
 			// Give AT time to process message
 			BlockUtils.mintBlock(repository);
 
 			// Send correct secrets to AT, from correct account
-			messageData = BTCACCT.buildRedeemMessage(secretA, secretB, partner.getAddress());
+			messageData = BitcoinACCTv1.buildRedeemMessage(secretA, secretB, partner.getAddress());
 			messageTransaction = sendMessage(repository, partner, messageData, atAddress);
 
 			// AT should send funds in the next block
@@ -412,8 +415,8 @@ public class AtTests extends Common {
 			assertTrue(atData.getIsFinished());
 
 			// AT should be in REDEEMED mode
-			CrossChainTradeData tradeData = BTCACCT.populateTradeData(repository, atData);
-			assertEquals(BTCACCT.Mode.REDEEMED, tradeData.mode);
+			CrossChainTradeData tradeData = BitcoinACCTv1.getInstance().populateTradeData(repository, atData);
+			assertEquals(AcctMode.REDEEMED, tradeData.mode);
 
 			// Check balances
 			long expectedBalance = partnersInitialBalance - messageTransaction.getTransactionData().getFee() + redeemAmount;
@@ -459,17 +462,17 @@ public class AtTests extends Common {
 
 			long partnersOfferMessageTransactionTimestamp = System.currentTimeMillis();
 			int lockTimeA = calcTestLockTimeA(partnersOfferMessageTransactionTimestamp);
-			int lockTimeB = BTCACCT.calcLockTimeB(partnersOfferMessageTransactionTimestamp, lockTimeA);
+			int lockTimeB = BitcoinACCTv1.calcLockTimeB(partnersOfferMessageTransactionTimestamp, lockTimeA);
 
 			// Send trade info to AT
-			byte[] messageData = BTCACCT.buildTradeMessage(partner.getAddress(), bitcoinPublicKeyHash, hashOfSecretA, lockTimeA, lockTimeB);
+			byte[] messageData = BitcoinACCTv1.buildTradeMessage(partner.getAddress(), bitcoinPublicKeyHash, hashOfSecretA, lockTimeA, lockTimeB);
 			MessageTransaction messageTransaction = sendMessage(repository, tradeAccount, messageData, atAddress);
 
 			// Give AT time to process message
 			BlockUtils.mintBlock(repository);
 
 			// Send correct secrets to AT, but from wrong account
-			messageData = BTCACCT.buildRedeemMessage(secretA, secretB, partner.getAddress());
+			messageData = BitcoinACCTv1.buildRedeemMessage(secretA, secretB, partner.getAddress());
 			messageTransaction = sendMessage(repository, bystander, messageData, atAddress);
 
 			// AT should NOT send funds in the next block
@@ -483,8 +486,8 @@ public class AtTests extends Common {
 			assertFalse(atData.getIsFinished());
 
 			// AT should still be in TRADE mode
-			CrossChainTradeData tradeData = BTCACCT.populateTradeData(repository, atData);
-			assertEquals(BTCACCT.Mode.TRADING, tradeData.mode);
+			CrossChainTradeData tradeData = BitcoinACCTv1.getInstance().populateTradeData(repository, atData);
+			assertEquals(AcctMode.TRADING, tradeData.mode);
 
 			// Check balances
 			long expectedBalance = partnersInitialBalance;
@@ -517,10 +520,10 @@ public class AtTests extends Common {
 
 			long partnersOfferMessageTransactionTimestamp = System.currentTimeMillis();
 			int lockTimeA = calcTestLockTimeA(partnersOfferMessageTransactionTimestamp);
-			int lockTimeB = BTCACCT.calcLockTimeB(partnersOfferMessageTransactionTimestamp, lockTimeA);
+			int lockTimeB = BitcoinACCTv1.calcLockTimeB(partnersOfferMessageTransactionTimestamp, lockTimeA);
 
 			// Send trade info to AT
-			byte[] messageData = BTCACCT.buildTradeMessage(partner.getAddress(), bitcoinPublicKeyHash, hashOfSecretA, lockTimeA, lockTimeB);
+			byte[] messageData = BitcoinACCTv1.buildTradeMessage(partner.getAddress(), bitcoinPublicKeyHash, hashOfSecretA, lockTimeA, lockTimeB);
 			MessageTransaction messageTransaction = sendMessage(repository, tradeAccount, messageData, atAddress);
 
 			// Give AT time to process message
@@ -529,7 +532,7 @@ public class AtTests extends Common {
 			// Send incorrect secrets to AT, from correct account
 			byte[] wrongSecret = new byte[32];
 			RANDOM.nextBytes(wrongSecret);
-			messageData = BTCACCT.buildRedeemMessage(wrongSecret, secretB, partner.getAddress());
+			messageData = BitcoinACCTv1.buildRedeemMessage(wrongSecret, secretB, partner.getAddress());
 			messageTransaction = sendMessage(repository, partner, messageData, atAddress);
 
 			// AT should NOT send funds in the next block
@@ -543,8 +546,8 @@ public class AtTests extends Common {
 			assertFalse(atData.getIsFinished());
 
 			// AT should still be in TRADE mode
-			CrossChainTradeData tradeData = BTCACCT.populateTradeData(repository, atData);
-			assertEquals(BTCACCT.Mode.TRADING, tradeData.mode);
+			CrossChainTradeData tradeData = BitcoinACCTv1.getInstance().populateTradeData(repository, atData);
+			assertEquals(AcctMode.TRADING, tradeData.mode);
 
 			long expectedBalance = partnersInitialBalance - messageTransaction.getTransactionData().getFee();
 			long actualBalance = partner.getConfirmedBalance(Asset.QORT);
@@ -552,7 +555,7 @@ public class AtTests extends Common {
 			assertEquals("Partner's balance incorrect", expectedBalance, actualBalance);
 
 			// Send incorrect secrets to AT, from correct account
-			messageData = BTCACCT.buildRedeemMessage(secretA, wrongSecret, partner.getAddress());
+			messageData = BitcoinACCTv1.buildRedeemMessage(secretA, wrongSecret, partner.getAddress());
 			messageTransaction = sendMessage(repository, partner, messageData, atAddress);
 
 			// AT should NOT send funds in the next block
@@ -565,8 +568,8 @@ public class AtTests extends Common {
 			assertFalse(atData.getIsFinished());
 
 			// AT should still be in TRADE mode
-			tradeData = BTCACCT.populateTradeData(repository, atData);
-			assertEquals(BTCACCT.Mode.TRADING, tradeData.mode);
+			tradeData = BitcoinACCTv1.getInstance().populateTradeData(repository, atData);
+			assertEquals(AcctMode.TRADING, tradeData.mode);
 
 			// Check balances
 			expectedBalance = partnersInitialBalance - messageTransaction.getTransactionData().getFee() * 2;
@@ -597,10 +600,10 @@ public class AtTests extends Common {
 
 			long partnersOfferMessageTransactionTimestamp = System.currentTimeMillis();
 			int lockTimeA = calcTestLockTimeA(partnersOfferMessageTransactionTimestamp);
-			int lockTimeB = BTCACCT.calcLockTimeB(partnersOfferMessageTransactionTimestamp, lockTimeA);
+			int lockTimeB = BitcoinACCTv1.calcLockTimeB(partnersOfferMessageTransactionTimestamp, lockTimeA);
 
 			// Send trade info to AT
-			byte[] messageData = BTCACCT.buildTradeMessage(partner.getAddress(), bitcoinPublicKeyHash, hashOfSecretA, lockTimeA, lockTimeB);
+			byte[] messageData = BitcoinACCTv1.buildTradeMessage(partner.getAddress(), bitcoinPublicKeyHash, hashOfSecretA, lockTimeA, lockTimeB);
 			MessageTransaction messageTransaction = sendMessage(repository, tradeAccount, messageData, atAddress);
 
 			// Give AT time to process message
@@ -621,8 +624,8 @@ public class AtTests extends Common {
 			assertFalse(atData.getIsFinished());
 
 			// AT should be in TRADING mode
-			CrossChainTradeData tradeData = BTCACCT.populateTradeData(repository, atData);
-			assertEquals(BTCACCT.Mode.TRADING, tradeData.mode);
+			CrossChainTradeData tradeData = BitcoinACCTv1.getInstance().populateTradeData(repository, atData);
+			assertEquals(AcctMode.TRADING, tradeData.mode);
 		}
 	}
 
@@ -654,7 +657,7 @@ public class AtTests extends Common {
 						HashCode.fromBytes(codeHash)));
 
 				// Not one of ours?
-				if (!Arrays.equals(codeHash, BTCACCT.CODE_BYTES_HASH))
+				if (!Arrays.equals(codeHash, BitcoinACCTv1.CODE_BYTES_HASH))
 					continue;
 
 				describeAt(repository, atAddress);
@@ -667,7 +670,7 @@ public class AtTests extends Common {
 	}
 
 	private DeployAtTransaction doDeploy(Repository repository, PrivateKeyAccount deployer, String tradeAddress) throws DataException {
-		byte[] creationBytes = BTCACCT.buildQortalAT(tradeAddress, bitcoinPublicKeyHash, hashOfSecretB, redeemAmount, bitcoinAmount, tradeTimeout);
+		byte[] creationBytes = BitcoinACCTv1.buildQortalAT(tradeAddress, bitcoinPublicKeyHash, hashOfSecretB, redeemAmount, bitcoinAmount, tradeTimeout);
 
 		long txTimestamp = System.currentTimeMillis();
 		byte[] lastReference = deployer.getLastReference();
@@ -744,7 +747,7 @@ public class AtTests extends Common {
 
 	private void describeAt(Repository repository, String atAddress) throws DataException {
 		ATData atData = repository.getATRepository().fromATAddress(atAddress);
-		CrossChainTradeData tradeData = BTCACCT.populateTradeData(repository, atData);
+		CrossChainTradeData tradeData = BitcoinACCTv1.getInstance().populateTradeData(repository, atData);
 
 		Function<Long, String> epochMilliFormatter = (timestamp) -> LocalDateTime.ofInstant(Instant.ofEpochMilli(timestamp), ZoneOffset.UTC).format(DateTimeFormatter.ofLocalizedDateTime(FormatStyle.MEDIUM));
 		int currentBlockHeight = repository.getBlockRepository().getBlockchainHeight();
@@ -760,17 +763,17 @@ public class AtTests extends Common {
 				+ "\texpected bitcoin: %s BTC,\n"
 				+ "\tcurrent block height: %d,\n",
 				tradeData.qortalAtAddress,
-				tradeData.mode.name(),
+				tradeData.mode,
 				tradeData.qortalCreator,
 				epochMilliFormatter.apply(tradeData.creationTimestamp),
 				Amounts.prettyAmount(tradeData.qortBalance),
 				atData.getIsFinished(),
 				HashCode.fromBytes(tradeData.hashOfSecretB).toString().substring(0, 40),
 				Amounts.prettyAmount(tradeData.qortAmount),
-				Amounts.prettyAmount(tradeData.expectedBitcoin),
+				Amounts.prettyAmount(tradeData.expectedForeignAmount),
 				currentBlockHeight));
 
-		if (tradeData.mode != BTCACCT.Mode.OFFERING && tradeData.mode != BTCACCT.Mode.CANCELLED) {
+		if (tradeData.mode != AcctMode.OFFERING && tradeData.mode != AcctMode.CANCELLED) {
 			System.out.println(String.format("\trefund height: block %d,\n"
 					+ "\tHASH160 of secret-A: %s,\n"
 					+ "\tBitcoin P2SH-A nLockTime: %d (%s),\n"

src/test/java/org/qortal/test/crosschain/bitcoinv1/DeployAT.java

@@ -1,12 +1,15 @@
-package org.qortal.test.btcacct;
+package org.qortal.test.crosschain.bitcoinv1;
 
-import java.security.Security;
-
-import org.bouncycastle.jce.provider.BouncyCastleProvider;
+import org.bitcoinj.core.Address;
+import org.bitcoinj.core.AddressFormatException;
+import org.bitcoinj.core.LegacyAddress;
+import org.bitcoinj.core.NetworkParameters;
 import org.qortal.account.PrivateKeyAccount;
 import org.qortal.asset.Asset;
 import org.qortal.controller.Controller;
-import org.qortal.crosschain.BTCACCT;
+import org.qortal.crosschain.Bitcoin;
+import org.qortal.crosschain.BitcoinACCTv1;
+import org.qortal.crosschain.Bitcoiny;
 import org.qortal.data.transaction.BaseTransactionData;
 import org.qortal.data.transaction.DeployAtTransactionData;
 import org.qortal.data.transaction.TransactionData;
@@ -16,7 +19,7 @@ import org.qortal.repository.Repository;
 import org.qortal.repository.RepositoryFactory;
 import org.qortal.repository.RepositoryManager;
 import org.qortal.repository.hsqldb.HSQLDBRepositoryFactory;
-import org.qortal.settings.Settings;
+import org.qortal.test.crosschain.apps.Common;
 import org.qortal.transaction.DeployAtTransaction;
 import org.qortal.transaction.Transaction;
 import org.qortal.transform.TransformationException;
@@ -28,20 +31,18 @@ import com.google.common.hash.HashCode;
 
 public class DeployAT {
 
-	public static final long atFundingExtra = 2000000L;
-
 	private static void usage(String error) {
 		if (error != null)
 			System.err.println(error);
 
-		System.err.println(String.format("usage: DeployAT <your Qortal PRIVATE key> <QORT amount> <BTC amount> <your Bitcoin PKH> <HASH160-of-secret> <AT funding amount> <trade-timeout>"));
+		System.err.println(String.format("usage: DeployAT <your Qortal PRIVATE key> <QORT amount> <AT funding amount> <BTC amount> <your Bitcoin PKH/P2PKH> <HASH160-of-secret> <trade-timeout>"));
 		System.err.println(String.format("example: DeployAT "
-				+ "AdTd9SUEYSdTW8mgK3Gu72K97bCHGdUwi2VvLNjUohot \\\n"
-				+ "\t80.4020 \\\n"
+				+ "7Eztjz2TsxwbrWUYEaSdLbASKQGTfK2rR7ViFc5gaiZw \\\n"
+				+ "\t10 \\\n"
+				+ "\t10.1 \\\n"
 				+ "\t0.00864200 \\\n"
-				+ "\t750b06757a2448b8a4abebaa6e4662833fd5ddbb \\\n"
+				+ "\t750b06757a2448b8a4abebaa6e4662833fd5ddbb (or mrBpZYYGYMwUa8tRjTiXfP1ySqNXszWN5h) \\\n"
 				+ "\tdaf59884b4d1aec8c1b17102530909ee43c0151a \\\n"
-				+ "\t123.456 \\\n"
 				+ "\t10080"));
 		System.exit(1);
 	}
@@ -50,15 +51,17 @@ public class DeployAT {
 		if (args.length != 7)
 			usage(null);
 
-		Security.insertProviderAt(new BouncyCastleProvider(), 0);
-		Settings.fileInstance("settings-test.json");
+		Common.init();
+
+		Bitcoiny bitcoiny = Bitcoin.getInstance();
+		NetworkParameters params = bitcoiny.getNetworkParameters();
 
 		byte[] refundPrivateKey = null;
 		long redeemAmount = 0;
+		long fundingAmount = 0;
 		long expectedBitcoin = 0;
 		byte[] bitcoinPublicKeyHash = null;
-		byte[] secretHash = null;
-		long fundingAmount = 0;
+		byte[] hashOfSecret = null;
 		int tradeTimeout = 0;
 
 		int argIndex = 0;
@@ -71,22 +74,30 @@ public class DeployAT {
 			if (redeemAmount <= 0)
 				usage("QORT amount must be positive");
 
+			fundingAmount = Long.parseLong(args[argIndex++]);
+			if (fundingAmount <= redeemAmount)
+				usage("AT funding amount must be greater than QORT redeem amount");
+
 			expectedBitcoin = Long.parseLong(args[argIndex++]);
 			if (expectedBitcoin <= 0)
 				usage("Expected BTC amount must be positive");
 
-			bitcoinPublicKeyHash = HashCode.fromString(args[argIndex++]).asBytes();
+			String bitcoinPKHish = args[argIndex++];
+			// Try P2PKH first
+			try {
+				Address bitcoinAddress = LegacyAddress.fromBase58(params, bitcoinPKHish);
+				bitcoinPublicKeyHash = bitcoinAddress.getHash();
+			} catch (AddressFormatException e) {
+				// Try parsing as PKH hex string instead
+				bitcoinPublicKeyHash = HashCode.fromString(bitcoinPKHish).asBytes();
+			}
 			if (bitcoinPublicKeyHash.length != 20)
 				usage("Bitcoin PKH must be 20 bytes");
 
-			secretHash = HashCode.fromString(args[argIndex++]).asBytes();
-			if (secretHash.length != 20)
+			hashOfSecret = HashCode.fromString(args[argIndex++]).asBytes();
+			if (hashOfSecret.length != 20)
 				usage("Hash of secret must be 20 bytes");
 
-			fundingAmount = Long.parseLong(args[argIndex++]);
-			if (fundingAmount <= redeemAmount)
-				usage("AT funding amount must be greater than QORT redeem amount");
-
 			tradeTimeout = Integer.parseInt(args[argIndex++]);
 			if (tradeTimeout < 60 || tradeTimeout > 50000)
 				usage("Trade timeout (minutes) must be between 60 and 50000");
@@ -98,12 +109,11 @@ public class DeployAT {
 			RepositoryFactory repositoryFactory = new HSQLDBRepositoryFactory(Controller.getRepositoryUrl());
 			RepositoryManager.setRepositoryFactory(repositoryFactory);
 		} catch (DataException e) {
-			throw new RuntimeException("Repository startup issue: " + e.getMessage());
+			System.err.println(String.format("Repository start-up issue: %s", e.getMessage()));
+			System.exit(2);
 		}
 
 		try (final Repository repository = RepositoryManager.getRepository()) {
-			System.out.println("Confirm the following is correct based on the info you've given:");
-
 			PrivateKeyAccount refundAccount = new PrivateKeyAccount(repository, refundPrivateKey);
 			System.out.println(String.format("Refund Qortal address: %s", refundAccount.getAddress()));
 
@@ -111,11 +121,11 @@ public class DeployAT {
 
 			System.out.println(String.format("AT funding amount: %s", Amounts.prettyAmount(fundingAmount)));
 
-			System.out.println(String.format("HASH160 of secret: %s", HashCode.fromBytes(secretHash)));
+			System.out.println(String.format("HASH160 of secret: %s", HashCode.fromBytes(hashOfSecret)));
 
 			// Deploy AT
-			byte[] creationBytes = BTCACCT.buildQortalAT(refundAccount.getAddress(), bitcoinPublicKeyHash, secretHash, redeemAmount, expectedBitcoin, tradeTimeout);
-			System.out.println("CIYAM AT creation bytes: " + HashCode.fromBytes(creationBytes).toString());
+			byte[] creationBytes = BitcoinACCTv1.buildQortalAT(refundAccount.getAddress(), bitcoinPublicKeyHash, hashOfSecret, redeemAmount, expectedBitcoin, tradeTimeout);
+			System.out.println("AT creation bytes: " + HashCode.fromBytes(creationBytes).toString());
 
 			long txTimestamp = System.currentTimeMillis();
 			byte[] lastReference = refundAccount.getLastReference();
@@ -149,11 +159,10 @@ public class DeployAT {
 				System.exit(2);
 			}
 
-			System.out.println(String.format("\nSigned transaction in base58, ready for POST /transactions/process:\n%s\n", Base58.encode(signedBytes)));
-		} catch (NumberFormatException e) {
-			usage(String.format("Number format exception: %s", e.getMessage()));
+			System.out.println(String.format("%nSigned transaction in base58, ready for POST /transactions/process:%n%s", Base58.encode(signedBytes)));
 		} catch (DataException e) {
-			throw new RuntimeException("Repository issue: " + e.getMessage());
+			System.err.println(String.format("Repository issue: %s", e.getMessage()));
+			System.exit(2);
 		}
 	}
 

src/test/java/org/qortal/test/crosschain/litecoinv1/DeployAT.java

@@ -0,0 +1,150 @@
+package org.qortal.test.crosschain.litecoinv1;
+
+import java.math.BigDecimal;
+
+import org.bitcoinj.core.ECKey;
+import org.qortal.account.PrivateKeyAccount;
+import org.qortal.asset.Asset;
+import org.qortal.controller.Controller;
+import org.qortal.crosschain.LitecoinACCTv1;
+import org.qortal.data.transaction.BaseTransactionData;
+import org.qortal.data.transaction.DeployAtTransactionData;
+import org.qortal.group.Group;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.repository.RepositoryFactory;
+import org.qortal.repository.RepositoryManager;
+import org.qortal.repository.hsqldb.HSQLDBRepositoryFactory;
+import org.qortal.test.crosschain.apps.Common;
+import org.qortal.transaction.DeployAtTransaction;
+import org.qortal.transform.TransformationException;
+import org.qortal.transform.transaction.TransactionTransformer;
+import org.qortal.utils.Amounts;
+import org.qortal.utils.Base58;
+
+import com.google.common.hash.HashCode;
+
+public class DeployAT {
+
+	private static void usage(String error) {
+		if (error != null)
+			System.err.println(error);
+
+		System.err.println(String.format("usage: DeployAT <your Qortal PRIVATE key> <QORT amount> <AT funding amount> <LTC amount> <trade-timeout>"));
+		System.err.println("A trading key-pair will be generated for you!");
+		System.err.println(String.format("example: DeployAT "
+				+ "7Eztjz2TsxwbrWUYEaSdLbASKQGTfK2rR7ViFc5gaiZw \\\n"
+				+ "\t10 \\\n"
+				+ "\t10.1 \\\n"
+				+ "\t0.00864200 \\\n"
+				+ "\t120"));
+		System.exit(1);
+	}
+
+	public static void main(String[] args) {
+		if (args.length != 5)
+			usage(null);
+
+		Common.init();
+
+		byte[] creatorPrivateKey = null;
+		long redeemAmount = 0;
+		long fundingAmount = 0;
+		long expectedLitecoin = 0;
+		int tradeTimeout = 0;
+
+		int argIndex = 0;
+		try {
+			creatorPrivateKey = Base58.decode(args[argIndex++]);
+			if (creatorPrivateKey.length != 32)
+				usage("Refund private key must be 32 bytes");
+
+			redeemAmount = new BigDecimal(args[argIndex++]).setScale(8).unscaledValue().longValue();
+			if (redeemAmount <= 0)
+				usage("QORT amount must be positive");
+
+			fundingAmount = new BigDecimal(args[argIndex++]).setScale(8).unscaledValue().longValue();
+			if (fundingAmount <= redeemAmount)
+				usage("AT funding amount must be greater than QORT redeem amount");
+
+			expectedLitecoin = new BigDecimal(args[argIndex++]).setScale(8).unscaledValue().longValue();
+			if (expectedLitecoin <= 0)
+				usage("Expected LTC amount must be positive");
+
+			tradeTimeout = Integer.parseInt(args[argIndex++]);
+			if (tradeTimeout < 60 || tradeTimeout > 50000)
+				usage("Trade timeout (minutes) must be between 60 and 50000");
+		} catch (IllegalArgumentException e) {
+			usage(String.format("Invalid argument %d: %s", argIndex, e.getMessage()));
+		}
+
+		try {
+			RepositoryFactory repositoryFactory = new HSQLDBRepositoryFactory(Controller.getRepositoryUrl());
+			RepositoryManager.setRepositoryFactory(repositoryFactory);
+		} catch (DataException e) {
+			System.err.println(String.format("Repository start-up issue: %s", e.getMessage()));
+			System.exit(2);
+		}
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount creatorAccount = new PrivateKeyAccount(repository, creatorPrivateKey);
+			System.out.println(String.format("Creator Qortal address: %s", creatorAccount.getAddress()));
+			System.out.println(String.format("QORT redeem amount: %s", Amounts.prettyAmount(redeemAmount)));
+			System.out.println(String.format("AT funding amount: %s", Amounts.prettyAmount(fundingAmount)));
+
+			// Generate trading key-pair
+			byte[] tradePrivateKey = new ECKey().getPrivKeyBytes();
+			PrivateKeyAccount tradeAccount = new PrivateKeyAccount(repository, tradePrivateKey);
+			byte[] litecoinPublicKeyHash = ECKey.fromPrivate(tradePrivateKey).getPubKeyHash();
+
+			System.out.println(String.format("Trade private key: %s", HashCode.fromBytes(tradePrivateKey)));
+
+			// Deploy AT
+			byte[] creationBytes = LitecoinACCTv1.buildQortalAT(tradeAccount.getAddress(), litecoinPublicKeyHash, redeemAmount, expectedLitecoin, tradeTimeout);
+			System.out.println("AT creation bytes: " + HashCode.fromBytes(creationBytes).toString());
+
+			long txTimestamp = System.currentTimeMillis();
+			byte[] lastReference = creatorAccount.getLastReference();
+
+			if (lastReference == null) {
+				System.err.println(String.format("Qortal account %s has no last reference", creatorAccount.getAddress()));
+				System.exit(2);
+			}
+
+			Long fee = null;
+			String name = "QORT-LTC cross-chain trade";
+			String description = String.format("Qortal-Litecoin cross-chain trade");
+			String atType = "ACCT";
+			String tags = "QORT-LTC ACCT";
+
+			BaseTransactionData baseTransactionData = new BaseTransactionData(txTimestamp, Group.NO_GROUP, lastReference, creatorAccount.getPublicKey(), fee, null);
+			DeployAtTransactionData deployAtTransactionData = new DeployAtTransactionData(baseTransactionData, name, description, atType, tags, creationBytes, fundingAmount, Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = new DeployAtTransaction(repository, deployAtTransactionData);
+
+			fee = deployAtTransaction.calcRecommendedFee();
+			deployAtTransactionData.setFee(fee);
+
+			deployAtTransaction.sign(creatorAccount);
+
+			byte[] signedBytes = null;
+			try {
+				signedBytes = TransactionTransformer.toBytes(deployAtTransactionData);
+			} catch (TransformationException e) {
+				System.err.println(String.format("Unable to convert transaction to base58: %s", e.getMessage()));
+				System.exit(2);
+			}
+
+			DeployAtTransaction.ensureATAddress(deployAtTransactionData);
+			String atAddress = deployAtTransactionData.getAtAddress();
+
+			System.out.println(String.format("%nSigned transaction in base58, ready for POST /transactions/process:%n%s", Base58.encode(signedBytes)));
+
+			System.out.println(String.format("AT address: %s", atAddress));
+		} catch (DataException e) {
+			System.err.println(String.format("Repository issue: %s", e.getMessage()));
+			System.exit(2);
+		}
+	}
+
+}

src/test/java/org/qortal/test/crosschain/litecoinv1/LitecoinACCTv1Tests.java

@@ -0,0 +1,770 @@
+package org.qortal.test.crosschain.litecoinv1;
+
+import static org.junit.Assert.*;
+
+import java.time.Instant;
+import java.time.LocalDateTime;
+import java.time.ZoneOffset;
+import java.time.format.DateTimeFormatter;
+import java.time.format.FormatStyle;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Random;
+import java.util.function.Function;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.qortal.account.Account;
+import org.qortal.account.PrivateKeyAccount;
+import org.qortal.asset.Asset;
+import org.qortal.block.Block;
+import org.qortal.crosschain.LitecoinACCTv1;
+import org.qortal.crosschain.AcctMode;
+import org.qortal.crypto.Crypto;
+import org.qortal.data.at.ATData;
+import org.qortal.data.at.ATStateData;
+import org.qortal.data.crosschain.CrossChainTradeData;
+import org.qortal.data.transaction.BaseTransactionData;
+import org.qortal.data.transaction.DeployAtTransactionData;
+import org.qortal.data.transaction.MessageTransactionData;
+import org.qortal.data.transaction.TransactionData;
+import org.qortal.group.Group;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.repository.RepositoryManager;
+import org.qortal.test.common.BlockUtils;
+import org.qortal.test.common.Common;
+import org.qortal.test.common.TransactionUtils;
+import org.qortal.transaction.DeployAtTransaction;
+import org.qortal.transaction.MessageTransaction;
+import org.qortal.utils.Amounts;
+
+import com.google.common.hash.HashCode;
+import com.google.common.primitives.Bytes;
+
+public class LitecoinACCTv1Tests extends Common {
+
+	public static final byte[] secretA = "This string is exactly 32 bytes!".getBytes();
+	public static final byte[] hashOfSecretA = Crypto.hash160(secretA); // daf59884b4d1aec8c1b17102530909ee43c0151a
+	public static final byte[] litecoinPublicKeyHash = HashCode.fromString("bb00bb11bb22bb33bb44bb55bb66bb77bb88bb99").asBytes();
+	public static final int tradeTimeout = 20; // blocks
+	public static final long redeemAmount = 80_40200000L;
+	public static final long fundingAmount = 123_45600000L;
+	public static final long litecoinAmount = 864200L; // 0.00864200 LTC
+
+	private static final Random RANDOM = new Random();
+
+	@Before
+	public void beforeTest() throws DataException {
+		Common.useDefaultSettings();
+	}
+
+	@Test
+	public void testCompile() {
+		PrivateKeyAccount tradeAccount = createTradeAccount(null);
+
+		byte[] creationBytes = LitecoinACCTv1.buildQortalAT(tradeAccount.getAddress(), litecoinPublicKeyHash, redeemAmount, litecoinAmount, tradeTimeout);
+		assertNotNull(creationBytes);
+
+		System.out.println("AT creation bytes: " + HashCode.fromBytes(creationBytes).toString());
+	}
+
+	@Test
+	public void testDeploy() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "chloe");
+			PrivateKeyAccount tradeAccount = createTradeAccount(repository);
+
+			PrivateKeyAccount partner = Common.getTestAccount(repository, "dilbert");
+
+			long deployersInitialBalance = deployer.getConfirmedBalance(Asset.QORT);
+			long partnersInitialBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, tradeAccount.getAddress());
+
+			long expectedBalance = deployersInitialBalance - fundingAmount - deployAtTransaction.getTransactionData().getFee();
+			long actualBalance = deployer.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Deployer's post-deployment balance incorrect", expectedBalance, actualBalance);
+
+			expectedBalance = fundingAmount;
+			actualBalance = deployAtTransaction.getATAccount().getConfirmedBalance(Asset.QORT);
+
+			assertEquals("AT's post-deployment balance incorrect", expectedBalance, actualBalance);
+
+			expectedBalance = partnersInitialBalance;
+			actualBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Partner's post-deployment balance incorrect", expectedBalance, actualBalance);
+
+			// Test orphaning
+			BlockUtils.orphanLastBlock(repository);
+
+			expectedBalance = deployersInitialBalance;
+			actualBalance = deployer.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Deployer's post-orphan/pre-deployment balance incorrect", expectedBalance, actualBalance);
+
+			expectedBalance = 0;
+			actualBalance = deployAtTransaction.getATAccount().getConfirmedBalance(Asset.QORT);
+
+			assertEquals("AT's post-orphan/pre-deployment balance incorrect", expectedBalance, actualBalance);
+
+			expectedBalance = partnersInitialBalance;
+			actualBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Partner's post-orphan/pre-deployment balance incorrect", expectedBalance, actualBalance);
+		}
+	}
+
+	@SuppressWarnings("unused")
+	@Test
+	public void testOfferCancel() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "chloe");
+			PrivateKeyAccount tradeAccount = createTradeAccount(repository);
+
+			PrivateKeyAccount partner = Common.getTestAccount(repository, "dilbert");
+
+			long deployersInitialBalance = deployer.getConfirmedBalance(Asset.QORT);
+			long partnersInitialBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, tradeAccount.getAddress());
+			Account at = deployAtTransaction.getATAccount();
+			String atAddress = at.getAddress();
+
+			long deployAtFee = deployAtTransaction.getTransactionData().getFee();
+			long deployersPostDeploymentBalance = deployersInitialBalance - fundingAmount - deployAtFee;
+
+			// Send creator's address to AT, instead of typical partner's address
+			byte[] messageData = LitecoinACCTv1.getInstance().buildCancelMessage(deployer.getAddress());
+			MessageTransaction messageTransaction = sendMessage(repository, deployer, messageData, atAddress);
+			long messageFee = messageTransaction.getTransactionData().getFee();
+
+			// AT should process 'cancel' message in next block
+			BlockUtils.mintBlock(repository);
+
+			describeAt(repository, atAddress);
+
+			// Check AT is finished
+			ATData atData = repository.getATRepository().fromATAddress(atAddress);
+			assertTrue(atData.getIsFinished());
+
+			// AT should be in CANCELLED mode
+			CrossChainTradeData tradeData = LitecoinACCTv1.getInstance().populateTradeData(repository, atData);
+			assertEquals(AcctMode.CANCELLED, tradeData.mode);
+
+			// Check balances
+			long expectedMinimumBalance = deployersPostDeploymentBalance;
+			long expectedMaximumBalance = deployersInitialBalance - deployAtFee - messageFee;
+
+			long actualBalance = deployer.getConfirmedBalance(Asset.QORT);
+
+			assertTrue(String.format("Deployer's balance %s should be above minimum %s", actualBalance, expectedMinimumBalance), actualBalance > expectedMinimumBalance);
+			assertTrue(String.format("Deployer's balance %s should be below maximum %s", actualBalance, expectedMaximumBalance), actualBalance < expectedMaximumBalance);
+
+			// Test orphaning
+			BlockUtils.orphanLastBlock(repository);
+
+			// Check balances
+			long expectedBalance = deployersPostDeploymentBalance - messageFee;
+			actualBalance = deployer.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Deployer's post-orphan/pre-refund balance incorrect", expectedBalance, actualBalance);
+		}
+	}
+
+	@SuppressWarnings("unused")
+	@Test
+	public void testOfferCancelInvalidLength() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "chloe");
+			PrivateKeyAccount tradeAccount = createTradeAccount(repository);
+
+			PrivateKeyAccount partner = Common.getTestAccount(repository, "dilbert");
+
+			long deployersInitialBalance = deployer.getConfirmedBalance(Asset.QORT);
+			long partnersInitialBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, tradeAccount.getAddress());
+			Account at = deployAtTransaction.getATAccount();
+			String atAddress = at.getAddress();
+
+			long deployAtFee = deployAtTransaction.getTransactionData().getFee();
+			long deployersPostDeploymentBalance = deployersInitialBalance - fundingAmount - deployAtFee;
+
+			// Instead of sending creator's address to AT, send too-short/invalid message
+			byte[] messageData = new byte[7];
+			RANDOM.nextBytes(messageData);
+			MessageTransaction messageTransaction = sendMessage(repository, deployer, messageData, atAddress);
+			long messageFee = messageTransaction.getTransactionData().getFee();
+
+			// AT should process 'cancel' message in next block
+			// As message is too short, it will be padded to 32bytes but cancel code doesn't care about message content, so should be ok
+			BlockUtils.mintBlock(repository);
+
+			describeAt(repository, atAddress);
+
+			// Check AT is finished
+			ATData atData = repository.getATRepository().fromATAddress(atAddress);
+			assertTrue(atData.getIsFinished());
+
+			// AT should be in CANCELLED mode
+			CrossChainTradeData tradeData = LitecoinACCTv1.getInstance().populateTradeData(repository, atData);
+			assertEquals(AcctMode.CANCELLED, tradeData.mode);
+		}
+	}
+
+	@SuppressWarnings("unused")
+	@Test
+	public void testTradingInfoProcessing() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "chloe");
+			PrivateKeyAccount tradeAccount = createTradeAccount(repository);
+
+			PrivateKeyAccount partner = Common.getTestAccount(repository, "dilbert");
+
+			long deployersInitialBalance = deployer.getConfirmedBalance(Asset.QORT);
+			long partnersInitialBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, tradeAccount.getAddress());
+			Account at = deployAtTransaction.getATAccount();
+			String atAddress = at.getAddress();
+
+			long partnersOfferMessageTransactionTimestamp = System.currentTimeMillis();
+			int lockTimeA = calcTestLockTimeA(partnersOfferMessageTransactionTimestamp);
+			int refundTimeout = LitecoinACCTv1.calcRefundTimeout(partnersOfferMessageTransactionTimestamp, lockTimeA);
+
+			// Send trade info to AT
+			byte[] messageData = LitecoinACCTv1.buildTradeMessage(partner.getAddress(), litecoinPublicKeyHash, hashOfSecretA, lockTimeA, refundTimeout);
+			MessageTransaction messageTransaction = sendMessage(repository, tradeAccount, messageData, atAddress);
+
+			Block postDeploymentBlock = BlockUtils.mintBlock(repository);
+			int postDeploymentBlockHeight = postDeploymentBlock.getBlockData().getHeight();
+
+			long deployAtFee = deployAtTransaction.getTransactionData().getFee();
+			long deployersPostDeploymentBalance = deployersInitialBalance - fundingAmount - deployAtFee;
+
+			describeAt(repository, atAddress);
+
+			ATData atData = repository.getATRepository().fromATAddress(atAddress);
+			CrossChainTradeData tradeData = LitecoinACCTv1.getInstance().populateTradeData(repository, atData);
+
+			// AT should be in TRADE mode
+			assertEquals(AcctMode.TRADING, tradeData.mode);
+
+			// Check hashOfSecretA was extracted correctly
+			assertTrue(Arrays.equals(hashOfSecretA, tradeData.hashOfSecretA));
+
+			// Check trade partner Qortal address was extracted correctly
+			assertEquals(partner.getAddress(), tradeData.qortalPartnerAddress);
+
+			// Check trade partner's Litecoin PKH was extracted correctly
+			assertTrue(Arrays.equals(litecoinPublicKeyHash, tradeData.partnerForeignPKH));
+
+			// Test orphaning
+			BlockUtils.orphanToBlock(repository, postDeploymentBlockHeight);
+
+			// Check balances
+			long expectedBalance = deployersPostDeploymentBalance;
+			long actualBalance = deployer.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Deployer's post-orphan/pre-refund balance incorrect", expectedBalance, actualBalance);
+		}
+	}
+
+	// TEST SENDING TRADING INFO BUT NOT FROM AT CREATOR (SHOULD BE IGNORED)
+	@SuppressWarnings("unused")
+	@Test
+	public void testIncorrectTradeSender() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "chloe");
+			PrivateKeyAccount tradeAccount = createTradeAccount(repository);
+
+			PrivateKeyAccount partner = Common.getTestAccount(repository, "dilbert");
+
+			PrivateKeyAccount bystander = Common.getTestAccount(repository, "bob");
+
+			long deployersInitialBalance = deployer.getConfirmedBalance(Asset.QORT);
+			long partnersInitialBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, tradeAccount.getAddress());
+			Account at = deployAtTransaction.getATAccount();
+			String atAddress = at.getAddress();
+
+			long partnersOfferMessageTransactionTimestamp = System.currentTimeMillis();
+			int lockTimeA = calcTestLockTimeA(partnersOfferMessageTransactionTimestamp);
+			int refundTimeout = LitecoinACCTv1.calcRefundTimeout(partnersOfferMessageTransactionTimestamp, lockTimeA);
+
+			// Send trade info to AT BUT NOT FROM AT CREATOR
+			byte[] messageData = LitecoinACCTv1.buildTradeMessage(partner.getAddress(), litecoinPublicKeyHash, hashOfSecretA, lockTimeA, refundTimeout);
+			MessageTransaction messageTransaction = sendMessage(repository, bystander, messageData, atAddress);
+
+			BlockUtils.mintBlock(repository);
+
+			long expectedBalance = partnersInitialBalance;
+			long actualBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Partner's post-initial-payout balance incorrect", expectedBalance, actualBalance);
+
+			describeAt(repository, atAddress);
+
+			ATData atData = repository.getATRepository().fromATAddress(atAddress);
+			CrossChainTradeData tradeData = LitecoinACCTv1.getInstance().populateTradeData(repository, atData);
+
+			// AT should still be in OFFER mode
+			assertEquals(AcctMode.OFFERING, tradeData.mode);
+		}
+	}
+
+	@SuppressWarnings("unused")
+	@Test
+	public void testAutomaticTradeRefund() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "chloe");
+			PrivateKeyAccount tradeAccount = createTradeAccount(repository);
+
+			PrivateKeyAccount partner = Common.getTestAccount(repository, "dilbert");
+
+			long deployersInitialBalance = deployer.getConfirmedBalance(Asset.QORT);
+			long partnersInitialBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, tradeAccount.getAddress());
+			Account at = deployAtTransaction.getATAccount();
+			String atAddress = at.getAddress();
+
+			long partnersOfferMessageTransactionTimestamp = System.currentTimeMillis();
+			int lockTimeA = calcTestLockTimeA(partnersOfferMessageTransactionTimestamp);
+			int refundTimeout = LitecoinACCTv1.calcRefundTimeout(partnersOfferMessageTransactionTimestamp, lockTimeA);
+
+			// Send trade info to AT
+			byte[] messageData = LitecoinACCTv1.buildTradeMessage(partner.getAddress(), litecoinPublicKeyHash, hashOfSecretA, lockTimeA, refundTimeout);
+			MessageTransaction messageTransaction = sendMessage(repository, tradeAccount, messageData, atAddress);
+
+			Block postDeploymentBlock = BlockUtils.mintBlock(repository);
+			int postDeploymentBlockHeight = postDeploymentBlock.getBlockData().getHeight();
+
+			// Check refund
+			long deployAtFee = deployAtTransaction.getTransactionData().getFee();
+			long deployersPostDeploymentBalance = deployersInitialBalance - fundingAmount - deployAtFee;
+
+			checkTradeRefund(repository, deployer, deployersInitialBalance, deployAtFee);
+
+			describeAt(repository, atAddress);
+
+			// Check AT is finished
+			ATData atData = repository.getATRepository().fromATAddress(atAddress);
+			assertTrue(atData.getIsFinished());
+
+			// AT should be in REFUNDED mode
+			CrossChainTradeData tradeData = LitecoinACCTv1.getInstance().populateTradeData(repository, atData);
+			assertEquals(AcctMode.REFUNDED, tradeData.mode);
+
+			// Test orphaning
+			BlockUtils.orphanToBlock(repository, postDeploymentBlockHeight);
+
+			// Check balances
+			long expectedBalance = deployersPostDeploymentBalance;
+			long actualBalance = deployer.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Deployer's post-orphan/pre-refund balance incorrect", expectedBalance, actualBalance);
+		}
+	}
+
+	@SuppressWarnings("unused")
+	@Test
+	public void testCorrectSecretCorrectSender() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "chloe");
+			PrivateKeyAccount tradeAccount = createTradeAccount(repository);
+
+			PrivateKeyAccount partner = Common.getTestAccount(repository, "dilbert");
+
+			long deployersInitialBalance = deployer.getConfirmedBalance(Asset.QORT);
+			long partnersInitialBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, tradeAccount.getAddress());
+			Account at = deployAtTransaction.getATAccount();
+			String atAddress = at.getAddress();
+
+			long partnersOfferMessageTransactionTimestamp = System.currentTimeMillis();
+			int lockTimeA = calcTestLockTimeA(partnersOfferMessageTransactionTimestamp);
+			int refundTimeout = LitecoinACCTv1.calcRefundTimeout(partnersOfferMessageTransactionTimestamp, lockTimeA);
+
+			// Send trade info to AT
+			byte[] messageData = LitecoinACCTv1.buildTradeMessage(partner.getAddress(), litecoinPublicKeyHash, hashOfSecretA, lockTimeA, refundTimeout);
+			MessageTransaction messageTransaction = sendMessage(repository, tradeAccount, messageData, atAddress);
+
+			// Give AT time to process message
+			BlockUtils.mintBlock(repository);
+
+			// Send correct secret to AT, from correct account
+			messageData = LitecoinACCTv1.buildRedeemMessage(secretA,  partner.getAddress());
+			messageTransaction = sendMessage(repository, partner, messageData, atAddress);
+
+			// AT should send funds in the next block
+			ATStateData preRedeemAtStateData = repository.getATRepository().getLatestATState(atAddress);
+			BlockUtils.mintBlock(repository);
+
+			describeAt(repository, atAddress);
+
+			// Check AT is finished
+			ATData atData = repository.getATRepository().fromATAddress(atAddress);
+			assertTrue(atData.getIsFinished());
+
+			// AT should be in REDEEMED mode
+			CrossChainTradeData tradeData = LitecoinACCTv1.getInstance().populateTradeData(repository, atData);
+			assertEquals(AcctMode.REDEEMED, tradeData.mode);
+
+			// Check balances
+			long expectedBalance = partnersInitialBalance - messageTransaction.getTransactionData().getFee() + redeemAmount;
+			long actualBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Partner's post-redeem balance incorrect", expectedBalance, actualBalance);
+
+			// Orphan redeem
+			BlockUtils.orphanLastBlock(repository);
+
+			// Check balances
+			expectedBalance = partnersInitialBalance - messageTransaction.getTransactionData().getFee();
+			actualBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Partner's post-orphan/pre-redeem balance incorrect", expectedBalance, actualBalance);
+
+			// Check AT state
+			ATStateData postOrphanAtStateData = repository.getATRepository().getLatestATState(atAddress);
+
+			assertTrue("AT states mismatch", Arrays.equals(preRedeemAtStateData.getStateData(), postOrphanAtStateData.getStateData()));
+		}
+	}
+
+	@SuppressWarnings("unused")
+	@Test
+	public void testCorrectSecretIncorrectSender() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "chloe");
+			PrivateKeyAccount tradeAccount = createTradeAccount(repository);
+
+			PrivateKeyAccount partner = Common.getTestAccount(repository, "dilbert");
+
+			PrivateKeyAccount bystander = Common.getTestAccount(repository, "bob");
+
+			long deployersInitialBalance = deployer.getConfirmedBalance(Asset.QORT);
+			long partnersInitialBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, tradeAccount.getAddress());
+			long deployAtFee = deployAtTransaction.getTransactionData().getFee();
+
+			Account at = deployAtTransaction.getATAccount();
+			String atAddress = at.getAddress();
+
+			long partnersOfferMessageTransactionTimestamp = System.currentTimeMillis();
+			int lockTimeA = calcTestLockTimeA(partnersOfferMessageTransactionTimestamp);
+			int refundTimeout = LitecoinACCTv1.calcRefundTimeout(partnersOfferMessageTransactionTimestamp, lockTimeA);
+
+			// Send trade info to AT
+			byte[] messageData = LitecoinACCTv1.buildTradeMessage(partner.getAddress(), litecoinPublicKeyHash, hashOfSecretA, lockTimeA, refundTimeout);
+			MessageTransaction messageTransaction = sendMessage(repository, tradeAccount, messageData, atAddress);
+
+			// Give AT time to process message
+			BlockUtils.mintBlock(repository);
+
+			// Send correct secret to AT, but from wrong account
+			messageData = LitecoinACCTv1.buildRedeemMessage(secretA, partner.getAddress());
+			messageTransaction = sendMessage(repository, bystander, messageData, atAddress);
+
+			// AT should NOT send funds in the next block
+			ATStateData preRedeemAtStateData = repository.getATRepository().getLatestATState(atAddress);
+			BlockUtils.mintBlock(repository);
+
+			describeAt(repository, atAddress);
+
+			// Check AT is NOT finished
+			ATData atData = repository.getATRepository().fromATAddress(atAddress);
+			assertFalse(atData.getIsFinished());
+
+			// AT should still be in TRADE mode
+			CrossChainTradeData tradeData = LitecoinACCTv1.getInstance().populateTradeData(repository, atData);
+			assertEquals(AcctMode.TRADING, tradeData.mode);
+
+			// Check balances
+			long expectedBalance = partnersInitialBalance;
+			long actualBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Partner's balance incorrect", expectedBalance, actualBalance);
+
+			// Check eventual refund
+			checkTradeRefund(repository, deployer, deployersInitialBalance, deployAtFee);
+		}
+	}
+
+	@SuppressWarnings("unused")
+	@Test
+	public void testIncorrectSecretCorrectSender() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "chloe");
+			PrivateKeyAccount tradeAccount = createTradeAccount(repository);
+
+			PrivateKeyAccount partner = Common.getTestAccount(repository, "dilbert");
+
+			long deployersInitialBalance = deployer.getConfirmedBalance(Asset.QORT);
+			long partnersInitialBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, tradeAccount.getAddress());
+			long deployAtFee = deployAtTransaction.getTransactionData().getFee();
+
+			Account at = deployAtTransaction.getATAccount();
+			String atAddress = at.getAddress();
+
+			long partnersOfferMessageTransactionTimestamp = System.currentTimeMillis();
+			int lockTimeA = calcTestLockTimeA(partnersOfferMessageTransactionTimestamp);
+			int refundTimeout = LitecoinACCTv1.calcRefundTimeout(partnersOfferMessageTransactionTimestamp, lockTimeA);
+
+			// Send trade info to AT
+			byte[] messageData = LitecoinACCTv1.buildTradeMessage(partner.getAddress(), litecoinPublicKeyHash, hashOfSecretA, lockTimeA, refundTimeout);
+			MessageTransaction messageTransaction = sendMessage(repository, tradeAccount, messageData, atAddress);
+
+			// Give AT time to process message
+			BlockUtils.mintBlock(repository);
+
+			// Send incorrect secret to AT, from correct account
+			byte[] wrongSecret = new byte[32];
+			RANDOM.nextBytes(wrongSecret);
+			messageData = LitecoinACCTv1.buildRedeemMessage(wrongSecret, partner.getAddress());
+			messageTransaction = sendMessage(repository, partner, messageData, atAddress);
+
+			// AT should NOT send funds in the next block
+			ATStateData preRedeemAtStateData = repository.getATRepository().getLatestATState(atAddress);
+			BlockUtils.mintBlock(repository);
+
+			describeAt(repository, atAddress);
+
+			// Check AT is NOT finished
+			ATData atData = repository.getATRepository().fromATAddress(atAddress);
+			assertFalse(atData.getIsFinished());
+
+			// AT should still be in TRADE mode
+			CrossChainTradeData tradeData = LitecoinACCTv1.getInstance().populateTradeData(repository, atData);
+			assertEquals(AcctMode.TRADING, tradeData.mode);
+
+			long expectedBalance = partnersInitialBalance - messageTransaction.getTransactionData().getFee();
+			long actualBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			assertEquals("Partner's balance incorrect", expectedBalance, actualBalance);
+
+			// Check eventual refund
+			checkTradeRefund(repository, deployer, deployersInitialBalance, deployAtFee);
+		}
+	}
+
+	@SuppressWarnings("unused")
+	@Test
+	public void testCorrectSecretCorrectSenderInvalidMessageLength() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "chloe");
+			PrivateKeyAccount tradeAccount = createTradeAccount(repository);
+
+			PrivateKeyAccount partner = Common.getTestAccount(repository, "dilbert");
+
+			long deployersInitialBalance = deployer.getConfirmedBalance(Asset.QORT);
+			long partnersInitialBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, tradeAccount.getAddress());
+			Account at = deployAtTransaction.getATAccount();
+			String atAddress = at.getAddress();
+
+			long partnersOfferMessageTransactionTimestamp = System.currentTimeMillis();
+			int lockTimeA = calcTestLockTimeA(partnersOfferMessageTransactionTimestamp);
+			int refundTimeout = LitecoinACCTv1.calcRefundTimeout(partnersOfferMessageTransactionTimestamp, lockTimeA);
+
+			// Send trade info to AT
+			byte[] messageData = LitecoinACCTv1.buildTradeMessage(partner.getAddress(), litecoinPublicKeyHash, hashOfSecretA, lockTimeA, refundTimeout);
+			MessageTransaction messageTransaction = sendMessage(repository, tradeAccount, messageData, atAddress);
+
+			// Give AT time to process message
+			BlockUtils.mintBlock(repository);
+
+			// Send correct secret to AT, from correct account, but missing receive address, hence incorrect length
+			messageData = Bytes.concat(secretA);
+			messageTransaction = sendMessage(repository, partner, messageData, atAddress);
+
+			// AT should NOT send funds in the next block
+			ATStateData preRedeemAtStateData = repository.getATRepository().getLatestATState(atAddress);
+			BlockUtils.mintBlock(repository);
+
+			describeAt(repository, atAddress);
+
+			// Check AT is NOT finished
+			ATData atData = repository.getATRepository().fromATAddress(atAddress);
+			assertFalse(atData.getIsFinished());
+
+			// AT should be in TRADING mode
+			CrossChainTradeData tradeData = LitecoinACCTv1.getInstance().populateTradeData(repository, atData);
+			assertEquals(AcctMode.TRADING, tradeData.mode);
+		}
+	}
+
+	@SuppressWarnings("unused")
+	@Test
+	public void testDescribeDeployed() throws DataException {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount deployer = Common.getTestAccount(repository, "chloe");
+			PrivateKeyAccount tradeAccount = createTradeAccount(repository);
+
+			PrivateKeyAccount partner = Common.getTestAccount(repository, "dilbert");
+
+			long deployersInitialBalance = deployer.getConfirmedBalance(Asset.QORT);
+			long partnersInitialBalance = partner.getConfirmedBalance(Asset.QORT);
+
+			DeployAtTransaction deployAtTransaction = doDeploy(repository, deployer, tradeAccount.getAddress());
+
+			List<ATData> executableAts = repository.getATRepository().getAllExecutableATs();
+
+			for (ATData atData : executableAts) {
+				String atAddress = atData.getATAddress();
+				byte[] codeBytes = atData.getCodeBytes();
+				byte[] codeHash = Crypto.digest(codeBytes);
+
+				System.out.println(String.format("%s: code length: %d byte%s, code hash: %s",
+						atAddress,
+						codeBytes.length,
+						(codeBytes.length != 1 ? "s": ""),
+						HashCode.fromBytes(codeHash)));
+
+				// Not one of ours?
+				if (!Arrays.equals(codeHash, LitecoinACCTv1.CODE_BYTES_HASH))
+					continue;
+
+				describeAt(repository, atAddress);
+			}
+		}
+	}
+
+	private int calcTestLockTimeA(long messageTimestamp) {
+		return (int) (messageTimestamp / 1000L + tradeTimeout * 60);
+	}
+
+	private DeployAtTransaction doDeploy(Repository repository, PrivateKeyAccount deployer, String tradeAddress) throws DataException {
+		byte[] creationBytes = LitecoinACCTv1.buildQortalAT(tradeAddress, litecoinPublicKeyHash, redeemAmount, litecoinAmount, tradeTimeout);
+
+		long txTimestamp = System.currentTimeMillis();
+		byte[] lastReference = deployer.getLastReference();
+
+		if (lastReference == null) {
+			System.err.println(String.format("Qortal account %s has no last reference", deployer.getAddress()));
+			System.exit(2);
+		}
+
+		Long fee = null;
+		String name = "QORT-LTC cross-chain trade";
+		String description = String.format("Qortal-Litecoin cross-chain trade");
+		String atType = "ACCT";
+		String tags = "QORT-LTC ACCT";
+
+		BaseTransactionData baseTransactionData = new BaseTransactionData(txTimestamp, Group.NO_GROUP, lastReference, deployer.getPublicKey(), fee, null);
+		TransactionData deployAtTransactionData = new DeployAtTransactionData(baseTransactionData, name, description, atType, tags, creationBytes, fundingAmount, Asset.QORT);
+
+		DeployAtTransaction deployAtTransaction = new DeployAtTransaction(repository, deployAtTransactionData);
+
+		fee = deployAtTransaction.calcRecommendedFee();
+		deployAtTransactionData.setFee(fee);
+
+		TransactionUtils.signAndMint(repository, deployAtTransactionData, deployer);
+
+		return deployAtTransaction;
+	}
+
+	private MessageTransaction sendMessage(Repository repository, PrivateKeyAccount sender, byte[] data, String recipient) throws DataException {
+		long txTimestamp = System.currentTimeMillis();
+		byte[] lastReference = sender.getLastReference();
+
+		if (lastReference == null) {
+			System.err.println(String.format("Qortal account %s has no last reference", sender.getAddress()));
+			System.exit(2);
+		}
+
+		Long fee = null;
+		int version = 4;
+		int nonce = 0;
+		long amount = 0;
+		Long assetId = null; // because amount is zero
+
+		BaseTransactionData baseTransactionData = new BaseTransactionData(txTimestamp, Group.NO_GROUP, lastReference, sender.getPublicKey(), fee, null);
+		TransactionData messageTransactionData = new MessageTransactionData(baseTransactionData, version, nonce, recipient, amount, assetId, data, false, false);
+
+		MessageTransaction messageTransaction = new MessageTransaction(repository, messageTransactionData);
+
+		fee = messageTransaction.calcRecommendedFee();
+		messageTransactionData.setFee(fee);
+
+		TransactionUtils.signAndMint(repository, messageTransactionData, sender);
+
+		return messageTransaction;
+	}
+
+	private void checkTradeRefund(Repository repository, Account deployer, long deployersInitialBalance, long deployAtFee) throws DataException {
+		long deployersPostDeploymentBalance = deployersInitialBalance - fundingAmount - deployAtFee;
+		int refundTimeout = tradeTimeout / 2 + 1; // close enough
+
+		// AT should automatically refund deployer after 'refundTimeout' blocks
+		for (int blockCount = 0; blockCount <= refundTimeout; ++blockCount)
+			BlockUtils.mintBlock(repository);
+
+		// We don't bother to exactly calculate QORT spent running AT for several blocks, but we do know the expected range
+		long expectedMinimumBalance = deployersPostDeploymentBalance;
+		long expectedMaximumBalance = deployersInitialBalance - deployAtFee;
+
+		long actualBalance = deployer.getConfirmedBalance(Asset.QORT);
+
+		assertTrue(String.format("Deployer's balance %s should be above minimum %s", actualBalance, expectedMinimumBalance), actualBalance > expectedMinimumBalance);
+		assertTrue(String.format("Deployer's balance %s should be below maximum %s", actualBalance, expectedMaximumBalance), actualBalance < expectedMaximumBalance);
+	}
+
+	private void describeAt(Repository repository, String atAddress) throws DataException {
+		ATData atData = repository.getATRepository().fromATAddress(atAddress);
+		CrossChainTradeData tradeData = LitecoinACCTv1.getInstance().populateTradeData(repository, atData);
+
+		Function<Long, String> epochMilliFormatter = (timestamp) -> LocalDateTime.ofInstant(Instant.ofEpochMilli(timestamp), ZoneOffset.UTC).format(DateTimeFormatter.ofLocalizedDateTime(FormatStyle.MEDIUM));
+		int currentBlockHeight = repository.getBlockRepository().getBlockchainHeight();
+
+		System.out.print(String.format("%s:\n"
+				+ "\tmode: %s\n"
+				+ "\tcreator: %s,\n"
+				+ "\tcreation timestamp: %s,\n"
+				+ "\tcurrent balance: %s QORT,\n"
+				+ "\tis finished: %b,\n"
+				+ "\tredeem payout: %s QORT,\n"
+				+ "\texpected Litecoin: %s LTC,\n"
+				+ "\tcurrent block height: %d,\n",
+				tradeData.qortalAtAddress,
+				tradeData.mode,
+				tradeData.qortalCreator,
+				epochMilliFormatter.apply(tradeData.creationTimestamp),
+				Amounts.prettyAmount(tradeData.qortBalance),
+				atData.getIsFinished(),
+				Amounts.prettyAmount(tradeData.qortAmount),
+				Amounts.prettyAmount(tradeData.expectedForeignAmount),
+				currentBlockHeight));
+
+		if (tradeData.mode != AcctMode.OFFERING && tradeData.mode != AcctMode.CANCELLED) {
+			System.out.println(String.format("\trefund timeout: %d minutes,\n"
+					+ "\trefund height: block %d,\n"
+					+ "\tHASH160 of secret-A: %s,\n"
+					+ "\tLitecoin P2SH-A nLockTime: %d (%s),\n"
+					+ "\ttrade partner: %s\n"
+					+ "\tpartner's receiving address: %s",
+					tradeData.refundTimeout,
+					tradeData.tradeRefundHeight,
+					HashCode.fromBytes(tradeData.hashOfSecretA).toString().substring(0, 40),
+					tradeData.lockTimeA, epochMilliFormatter.apply(tradeData.lockTimeA * 1000L),
+					tradeData.qortalPartnerAddress,
+					tradeData.qortalPartnerReceivingAddress));
+		}
+	}
+
+	private PrivateKeyAccount createTradeAccount(Repository repository) {
+		// We actually use a known test account with funds to avoid PoW compute
+		return Common.getTestAccount(repository, "alice");
+	}
+
+}

src/test/java/org/qortal/test/crosschain/litecoinv1/SendCancelMessage.java

@@ -0,0 +1,90 @@
+package org.qortal.test.crosschain.litecoinv1;
+
+import org.qortal.account.PrivateKeyAccount;
+import org.qortal.controller.Controller;
+import org.qortal.crosschain.LitecoinACCTv1;
+import org.qortal.crypto.Crypto;
+import org.qortal.group.Group;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.repository.RepositoryFactory;
+import org.qortal.repository.RepositoryManager;
+import org.qortal.repository.hsqldb.HSQLDBRepositoryFactory;
+import org.qortal.test.crosschain.apps.Common;
+import org.qortal.transaction.MessageTransaction;
+import org.qortal.transform.TransformationException;
+import org.qortal.transform.transaction.TransactionTransformer;
+import org.qortal.utils.Base58;
+
+public class SendCancelMessage {
+
+	private static void usage(String error) {
+		if (error != null)
+			System.err.println(error);
+
+		System.err.println(String.format("usage: SendCancelMessage <your Qortal PRIVATE key> <AT address>"));
+		System.err.println(String.format("example: SendCancelMessage "
+				+ "7Eztjz2TsxwbrWUYEaSdLbASKQGTfK2rR7ViFc5gaiZw \\\n"
+				+ "\tAaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"));
+		System.exit(1);
+	}
+
+	public static void main(String[] args) {
+		if (args.length != 2)
+			usage(null);
+
+		Common.init();
+
+		byte[] qortalPrivateKey = null;
+		String atAddress = null;
+
+		int argIndex = 0;
+		try {
+			qortalPrivateKey = Base58.decode(args[argIndex++]);
+			if (qortalPrivateKey.length != 32)
+				usage("Refund private key must be 32 bytes");
+
+			atAddress = args[argIndex++];
+			if (!Crypto.isValidAtAddress(atAddress))
+				usage("Invalid AT address");
+		} catch (IllegalArgumentException e) {
+			usage(String.format("Invalid argument %d: %s", argIndex, e.getMessage()));
+		}
+
+		try {
+			RepositoryFactory repositoryFactory = new HSQLDBRepositoryFactory(Controller.getRepositoryUrl());
+			RepositoryManager.setRepositoryFactory(repositoryFactory);
+		} catch (DataException e) {
+			System.err.println(String.format("Repository start-up issue: %s", e.getMessage()));
+			System.exit(2);
+		}
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount qortalAccount = new PrivateKeyAccount(repository, qortalPrivateKey);
+
+			String creatorQortalAddress = qortalAccount.getAddress();
+			System.out.println(String.format("Qortal address: %s", creatorQortalAddress));
+
+			byte[] messageData = LitecoinACCTv1.getInstance().buildCancelMessage(creatorQortalAddress);
+			MessageTransaction messageTransaction = MessageTransaction.build(repository, qortalAccount, Group.NO_GROUP, atAddress, messageData, false, false);
+
+			System.out.println("Computing nonce...");
+			messageTransaction.computeNonce();
+			messageTransaction.sign(qortalAccount);
+
+			byte[] signedBytes = null;
+			try {
+				signedBytes = TransactionTransformer.toBytes(messageTransaction.getTransactionData());
+			} catch (TransformationException e) {
+				System.err.println(String.format("Unable to convert transaction to bytes: %s", e.getMessage()));
+				System.exit(2);
+			}
+
+			System.out.println(String.format("%nSigned transaction in base58, ready for POST /transactions/process:%n%s", Base58.encode(signedBytes)));
+		} catch (DataException e) {
+			System.err.println(String.format("Repository issue: %s", e.getMessage()));
+			System.exit(2);
+		}
+	}
+
+}

src/test/java/org/qortal/test/crosschain/litecoinv1/SendRedeemMessage.java

@@ -0,0 +1,101 @@
+package org.qortal.test.crosschain.litecoinv1;
+
+import org.qortal.account.PrivateKeyAccount;
+import org.qortal.controller.Controller;
+import org.qortal.crosschain.LitecoinACCTv1;
+import org.qortal.crypto.Crypto;
+import org.qortal.group.Group;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.repository.RepositoryFactory;
+import org.qortal.repository.RepositoryManager;
+import org.qortal.repository.hsqldb.HSQLDBRepositoryFactory;
+import org.qortal.test.crosschain.apps.Common;
+import org.qortal.transaction.MessageTransaction;
+import org.qortal.transform.TransformationException;
+import org.qortal.transform.transaction.TransactionTransformer;
+import org.qortal.utils.Base58;
+
+import com.google.common.hash.HashCode;
+
+public class SendRedeemMessage {
+
+	private static void usage(String error) {
+		if (error != null)
+			System.err.println(error);
+
+		System.err.println(String.format("usage: SendRedeemMessage <partner trade PRIVATE key> <AT address> <secret> <Qortal receive address>"));
+		System.err.println(String.format("example: SendRedeemMessage "
+				+ "dbfe739f5a3ecf7b0a22cea71f73d86ec71355b740e5972bcdf9e8bb4721ab9d \\\n"
+				+ "\tAaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa \\\n"
+				+ "\t5468697320737472696e672069732065786163746c7920333220627974657321 \\\n"
+				+ "\tQqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq"));
+		System.exit(1);
+	}
+
+	public static void main(String[] args) {
+		if (args.length != 4)
+			usage(null);
+
+		Common.init();
+
+		byte[] tradePrivateKey = null;
+		String atAddress = null;
+		byte[] secret = null;
+		String receiveAddress = null;
+
+		int argIndex = 0;
+		try {
+			tradePrivateKey = HashCode.fromString(args[argIndex++]).asBytes();
+			if (tradePrivateKey.length != 32)
+				usage("Refund private key must be 32 bytes");
+
+			atAddress = args[argIndex++];
+			if (!Crypto.isValidAtAddress(atAddress))
+				usage("Invalid AT address");
+
+			secret = HashCode.fromString(args[argIndex++]).asBytes();
+			if (secret.length != 32)
+				usage("Secret must be 32 bytes");
+
+			receiveAddress = args[argIndex++];
+			if (!Crypto.isValidAddress(receiveAddress))
+				usage("Invalid Qortal receive address");
+		} catch (IllegalArgumentException e) {
+			usage(String.format("Invalid argument %d: %s", argIndex, e.getMessage()));
+		}
+
+		try {
+			RepositoryFactory repositoryFactory = new HSQLDBRepositoryFactory(Controller.getRepositoryUrl());
+			RepositoryManager.setRepositoryFactory(repositoryFactory);
+		} catch (DataException e) {
+			System.err.println(String.format("Repository start-up issue: %s", e.getMessage()));
+			System.exit(2);
+		}
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount tradeAccount = new PrivateKeyAccount(repository, tradePrivateKey);
+
+			byte[] messageData = LitecoinACCTv1.buildRedeemMessage(secret, receiveAddress);
+			MessageTransaction messageTransaction = MessageTransaction.build(repository, tradeAccount, Group.NO_GROUP, atAddress, messageData, false, false);
+
+			System.out.println("Computing nonce...");
+			messageTransaction.computeNonce();
+			messageTransaction.sign(tradeAccount);
+
+			byte[] signedBytes = null;
+			try {
+				signedBytes = TransactionTransformer.toBytes(messageTransaction.getTransactionData());
+			} catch (TransformationException e) {
+				System.err.println(String.format("Unable to convert transaction to bytes: %s", e.getMessage()));
+				System.exit(2);
+			}
+
+			System.out.println(String.format("%nSigned transaction in base58, ready for POST /transactions/process:%n%s", Base58.encode(signedBytes)));
+		} catch (DataException e) {
+			System.err.println(String.format("Repository issue: %s", e.getMessage()));
+			System.exit(2);
+		}
+	}
+
+}

src/test/java/org/qortal/test/crosschain/litecoinv1/SendTradeMessage.java

@@ -0,0 +1,118 @@
+package org.qortal.test.crosschain.litecoinv1;
+
+import org.qortal.account.PrivateKeyAccount;
+import org.qortal.controller.Controller;
+import org.qortal.crosschain.LitecoinACCTv1;
+import org.qortal.crypto.Crypto;
+import org.qortal.group.Group;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.repository.RepositoryFactory;
+import org.qortal.repository.RepositoryManager;
+import org.qortal.repository.hsqldb.HSQLDBRepositoryFactory;
+import org.qortal.test.crosschain.apps.Common;
+import org.qortal.transaction.MessageTransaction;
+import org.qortal.transform.TransformationException;
+import org.qortal.transform.transaction.TransactionTransformer;
+import org.qortal.utils.Base58;
+import org.qortal.utils.NTP;
+
+import com.google.common.hash.HashCode;
+
+public class SendTradeMessage {
+
+	private static void usage(String error) {
+		if (error != null)
+			System.err.println(error);
+
+		System.err.println(String.format("usage: SendTradeMessage <trade PRIVATE key> <AT address> <partner trade Qortal address> <partner tradeLitecoin PKH/P2PKH> <hash-of-secret> <locktime>"));
+		System.err.println(String.format("example: SendTradeMessage "
+				+ "ed77aa2c62d785a9428725fc7f95b907be8a1cc43213239876a62cf70fdb6ecb \\\n"
+				+ "\tAaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa \\\n"
+				+ "\tQqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq \\\n"
+				+ "\tffffffffffffffffffffffffffffffffffffffff \\\n"
+				+ "\tdaf59884b4d1aec8c1b17102530909ee43c0151a \\\n"
+				+ "\t1600184800"));
+		System.exit(1);
+	}
+
+	public static void main(String[] args) {
+		if (args.length != 6)
+			usage(null);
+
+		Common.init();
+
+		byte[] tradePrivateKey = null;
+		String atAddress = null;
+		String partnerTradeAddress = null;
+		byte[] partnerTradePublicKeyHash = null;
+		byte[] hashOfSecret = null;
+		int lockTime = 0;
+
+		int argIndex = 0;
+		try {
+			tradePrivateKey = HashCode.fromString(args[argIndex++]).asBytes();
+			if (tradePrivateKey.length != 32)
+				usage("Refund private key must be 32 bytes");
+
+			atAddress = args[argIndex++];
+			if (!Crypto.isValidAtAddress(atAddress))
+				usage("Invalid AT address");
+
+			partnerTradeAddress = args[argIndex++];
+			if (!Crypto.isValidAddress(partnerTradeAddress))
+				usage("Invalid partner trade Qortal address");
+
+			partnerTradePublicKeyHash = HashCode.fromString(args[argIndex++]).asBytes();
+			if (partnerTradePublicKeyHash.length != 20)
+				usage("Partner trade PKH must be 20 bytes");
+
+			hashOfSecret = HashCode.fromString(args[argIndex++]).asBytes();
+			if (hashOfSecret.length != 20)
+				usage("HASH160 of secret must be 20 bytes");
+
+			lockTime = Integer.parseInt(args[argIndex++]);
+		} catch (IllegalArgumentException e) {
+			usage(String.format("Invalid argument %d: %s", argIndex, e.getMessage()));
+		}
+
+		try {
+			RepositoryFactory repositoryFactory = new HSQLDBRepositoryFactory(Controller.getRepositoryUrl());
+			RepositoryManager.setRepositoryFactory(repositoryFactory);
+		} catch (DataException e) {
+			System.err.println(String.format("Repository start-up issue: %s", e.getMessage()));
+			System.exit(2);
+		}
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			PrivateKeyAccount tradeAccount = new PrivateKeyAccount(repository, tradePrivateKey);
+
+			int refundTimeout = LitecoinACCTv1.calcRefundTimeout(NTP.getTime(), lockTime);
+			if (refundTimeout < 1) {
+				System.err.println("Refund timeout too small. Is locktime in the past?");
+				System.exit(2);
+			}
+
+			byte[] messageData = LitecoinACCTv1.buildTradeMessage(partnerTradeAddress, partnerTradePublicKeyHash, hashOfSecret, lockTime, refundTimeout);
+			MessageTransaction messageTransaction = MessageTransaction.build(repository, tradeAccount, Group.NO_GROUP, atAddress, messageData, false, false);
+
+			System.out.println("Computing nonce...");
+			messageTransaction.computeNonce();
+			messageTransaction.sign(tradeAccount);
+
+			byte[] signedBytes = null;
+			try {
+				signedBytes = TransactionTransformer.toBytes(messageTransaction.getTransactionData());
+			} catch (TransformationException e) {
+				System.err.println(String.format("Unable to convert transaction to bytes: %s", e.getMessage()));
+				System.exit(2);
+			}
+
+			System.out.println(String.format("%nSigned transaction in base58, ready for POST /transactions/process:%n%s", Base58.encode(signedBytes)));
+		} catch (DataException e) {
+			System.err.println(String.format("Repository issue: %s", e.getMessage()));
+			System.exit(2);
+		}
+	}
+
+}