Added documentation link in Q-Apps branch, as it has now moved to the master branch. Don't merge this commit into master.

Based on work by @QuickMythril, but modified to be generic.

.github/workflows/pr-testing.yml

@@ -8,16 +8,16 @@ jobs:
   mavenTesting:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
     - name: Cache local Maven repository
-      uses: actions/cache@v2
+      uses: actions/cache@v3
       with:
         path: ~/.m2/repository
         key: ${{ runner.os }}-maven-${{ hashFiles('**/pom.xml') }}
         restore-keys: |
           ${{ runner.os }}-maven-
     - name: Set up the Java JDK
-      uses: actions/setup-java@v2
+      uses: actions/setup-java@v3
       with:
         java-version: '11'
         distribution: 'adopt'

.gitignore

@@ -14,7 +14,6 @@
 /.mvn.classpath
 /notes*
 /settings.json
-/testnet*
 /settings*.json
 /testchain*.json
 /run-testnet*.sh

Q-Apps.md

@@ -0,0 +1,3 @@
+# Qortal Project - Q-Apps Documentation
+
+The Q-Apps documentation has moved [here](https://github.com/Qortal/qortal/blob/master/Q-Apps.md).

WindowsInstaller/Qortal.aip

@@ -17,10 +17,10 @@
     <ROW Property="Manufacturer" Value="Qortal"/>
     <ROW Property="MsiLogging" MultiBuildValue="DefaultBuild:vp"/>
     <ROW Property="NTP_GOOD" Value="false"/>
-    <ROW Property="ProductCode" Value="1033:{ADE0C9E9-F7D9-4829-8626-8571C735C4D7} 1049:{F5230C0A-9D8C-4C70-AC72-17CECC8273B8} 2052:{D5A0760C-E5B3-4C4C-97B0-81CC445F07B9} 2057:{EF5EF0BE-0B00-4F5C-A2A0-DF2CB82FF20D} " Type="16"/>
+    <ROW Property="ProductCode" Value="1033:{CB85115E-ECCE-4B3D-BB7F-6251A2764922} 1049:{09AC1C62-4E33-4312-826A-38F597ED1B17} 2052:{3CF701B3-E118-4A31-A4B7-156CEA19FBCC} 2057:{468F337D-0EF8-41D1-B5DE-4EEE66BA2AF6} " Type="16"/>
     <ROW Property="ProductLanguage" Value="2057"/>
     <ROW Property="ProductName" Value="Qortal"/>
-    <ROW Property="ProductVersion" Value="3.6.3" Type="32"/>
+    <ROW Property="ProductVersion" Value="3.8.5" Type="32"/>
     <ROW Property="RECONFIG_NTP" Value="true"/>
     <ROW Property="REMOVE_BLOCKCHAIN" Value="YES" Type="4"/>
     <ROW Property="REPAIR_BLOCKCHAIN" Value="YES" Type="4"/>
@@ -212,7 +212,7 @@
     <ROW Component="ADDITIONAL_LICENSE_INFO_71" ComponentId="{12A3ADBE-BB7A-496C-8869-410681E6232F}" Directory_="jdk.zipfs_Dir" Attributes="0" KeyPath="ADDITIONAL_LICENSE_INFO_71" Type="0"/>
     <ROW Component="ADDITIONAL_LICENSE_INFO_8" ComponentId="{D53AD95E-CF96-4999-80FC-5812277A7456}" Directory_="java.naming_Dir" Attributes="0" KeyPath="ADDITIONAL_LICENSE_INFO_8" Type="0"/>
     <ROW Component="ADDITIONAL_LICENSE_INFO_9" ComponentId="{6B7EA9B0-5D17-47A8-B78C-FACE86D15E01}" Directory_="java.net.http_Dir" Attributes="0" KeyPath="ADDITIONAL_LICENSE_INFO_9" Type="0"/>
-    <ROW Component="AI_CustomARPName" ComponentId="{F4F774B9-18DC-4740-9552-EA16B98801C9}" Directory_="APPDIR" Attributes="260" KeyPath="DisplayName" Options="1"/>
+    <ROW Component="AI_CustomARPName" ComponentId="{094B5D07-2258-4A39-9917-2E2F7F6E210B}" Directory_="APPDIR" Attributes="260" KeyPath="DisplayName" Options="1"/>
     <ROW Component="AI_ExePath" ComponentId="{3644948D-AE0B-41BB-9FAF-A79E70490A08}" Directory_="APPDIR" Attributes="260" KeyPath="AI_ExePath"/>
     <ROW Component="APPDIR" ComponentId="{680DFDDE-3FB4-47A5-8FF5-934F576C6F91}" Directory_="APPDIR" Attributes="0"/>
     <ROW Component="AccessBridgeCallbacks.h" ComponentId="{288055D1-1062-47A3-AA44-5601B4E38AED}" Directory_="bridge_Dir" Attributes="0" KeyPath="AccessBridgeCallbacks.h" Type="0"/>

pom.xml

@@ -3,7 +3,7 @@
 	<modelVersion>4.0.0</modelVersion>
 	<groupId>org.qortal</groupId>
 	<artifactId>qortal</artifactId>
-	<version>3.8.0</version>
+	<version>3.9.1</version>
 	<packaging>jar</packaging>
 	<properties>
 		<skipTests>true</skipTests>
@@ -36,6 +36,7 @@
 		<java-diff-utils.version>4.10</java-diff-utils.version>
 		<grpc.version>1.45.1</grpc.version>
 		<protobuf.version>3.19.4</protobuf.version>
+		<simplemagic.version>1.17</simplemagic.version>
 	</properties>
 	<build>
 		<sourceDirectory>src/main/java</sourceDirectory>
@@ -147,6 +148,7 @@
 										tagsSorter: "alpha",
 										operationsSorter:
 										"alpha",
+										validatorUrl: false,
 									</value>
 								</replacement>
 							</replacements>
@@ -304,6 +306,7 @@
 									implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
 									<mainClass>org.qortal.controller.Controller</mainClass>
 									<manifestEntries>
+										<Multi-Release>true</Multi-Release>
 										<Class-Path>. ..</Class-Path>
 									</manifestEntries>
 								</transformer>
@@ -727,5 +730,10 @@
 			<artifactId>protobuf-java</artifactId>
 			<version>${protobuf.version}</version>
 		</dependency>
+		<dependency>
+			<groupId>com.j256.simplemagic</groupId>
+			<artifactId>simplemagic</artifactId>
+			<version>${simplemagic.version}</version>
+		</dependency>
 	</dependencies>
 </project>

src/main/java/org/qortal/account/SelfSponsorshipAlgoV1.java

@@ -52,6 +52,11 @@ public class SelfSponsorshipAlgoV1 {
 
 
     public void run() throws DataException {
+        if (this.accountData == null) {
+            // Nothing to do
+            return;
+        }
+
         this.fetchSponsorshipRewardShares();
         if (this.sponsorshipRewardShares.isEmpty()) {
             // Nothing to do

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

@@ -79,7 +79,7 @@ public enum ApiError {
 	// BUYER_ALREADY_OWNER(411, 422),
 
 	// POLLS
-	// POLL_NO_EXISTS(501, 404),
+	POLL_NO_EXISTS(501, 404),
 	// POLL_ALREADY_EXISTS(502, 422),
 	// DUPLICATE_OPTION(503, 422),
 	// POLL_OPTION_NO_EXISTS(504, 404),

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

@@ -3,6 +3,7 @@ package org.qortal.api;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.UnsupportedEncodingException;
+import java.io.Writer;
 import java.net.HttpURLConnection;
 import java.net.InetSocketAddress;
 import java.net.Socket;
@@ -20,14 +21,12 @@ import javax.net.ssl.SNIHostName;
 import javax.net.ssl.SNIServerName;
 import javax.net.ssl.SSLParameters;
 import javax.net.ssl.SSLSocket;
-import javax.xml.bind.JAXBContext;
-import javax.xml.bind.JAXBException;
-import javax.xml.bind.UnmarshalException;
-import javax.xml.bind.Unmarshaller;
+import javax.xml.bind.*;
 import javax.xml.transform.stream.StreamSource;
 
 import org.eclipse.persistence.exceptions.XMLMarshalException;
 import org.eclipse.persistence.jaxb.JAXBContextFactory;
+import org.eclipse.persistence.jaxb.MarshallerProperties;
 import org.eclipse.persistence.jaxb.UnmarshallerProperties;
 
 public class ApiRequest {
@@ -107,6 +106,36 @@ public class ApiRequest {
 		}
 	}
 
+	private static Marshaller createMarshaller(Class<?> objectClass) {
+		try {
+			// Create JAXB context aware of object's class
+			JAXBContext jc = JAXBContextFactory.createContext(new Class[] { objectClass }, null);
+
+			// Create marshaller
+			Marshaller marshaller = jc.createMarshaller();
+
+			// Set the marshaller media type to JSON
+			marshaller.setProperty(MarshallerProperties.MEDIA_TYPE, "application/json");
+
+			// Tell marshaller not to include JSON root element in the output
+			marshaller.setProperty(MarshallerProperties.JSON_INCLUDE_ROOT, false);
+
+			return marshaller;
+		} catch (JAXBException e) {
+			throw new RuntimeException("Unable to create API marshaller", e);
+		}
+	}
+
+	public static void marshall(Writer writer, Object object) throws IOException {
+		Marshaller marshaller = createMarshaller(object.getClass());
+
+		try {
+			marshaller.marshal(object, writer);
+		} catch (JAXBException e) {
+			throw new IOException("Unable to create marshall object for API", e);
+		}
+	}
+
 	public static String getParamsString(Map<String, String> params) {
 		StringBuilder result = new StringBuilder();
 

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

@@ -13,8 +13,8 @@ import java.security.SecureRandom;
 
 import javax.net.ssl.KeyManagerFactory;
 import javax.net.ssl.SSLContext;
+import javax.servlet.http.HttpServletRequest;
 
-import org.checkerframework.checker.units.qual.A;
 import org.eclipse.jetty.http.HttpVersion;
 import org.eclipse.jetty.rewrite.handler.RedirectPatternRule;
 import org.eclipse.jetty.rewrite.handler.RewriteHandler;
@@ -41,6 +41,7 @@ import org.glassfish.jersey.servlet.ServletContainer;
 import org.qortal.api.resource.AnnotationPostProcessor;
 import org.qortal.api.resource.ApiDefinition;
 import org.qortal.api.websocket.*;
+import org.qortal.network.Network;
 import org.qortal.settings.Settings;
 
 public class ApiService {
@@ -51,9 +52,11 @@ public class ApiService {
 	private Server server;
 	private ApiKey apiKey;
 
+	public static final String API_VERSION_HEADER = "X-API-VERSION";
+
 	private ApiService() {
 		this.config = new ResourceConfig();
-		this.config.packages("org.qortal.api.resource");
+		this.config.packages("org.qortal.api.resource", "org.qortal.api.restricted.resource");
 		this.config.register(OpenApiResource.class);
 		this.config.register(ApiDefinition.class);
 		this.config.register(AnnotationPostProcessor.class);
@@ -123,13 +126,13 @@ public class ApiService {
 				ServerConnector portUnifiedConnector = new ServerConnector(this.server,
 						new DetectorConnectionFactory(sslConnectionFactory),
 						httpConnectionFactory);
-				portUnifiedConnector.setHost(Settings.getInstance().getBindAddress());
+				portUnifiedConnector.setHost(Network.getInstance().getBindAddress());
 				portUnifiedConnector.setPort(Settings.getInstance().getApiPort());
 
 				this.server.addConnector(portUnifiedConnector);
 			} else {
 				// Non-SSL
-				InetAddress bindAddr = InetAddress.getByName(Settings.getInstance().getBindAddress());
+				InetAddress bindAddr = InetAddress.getByName(Network.getInstance().getBindAddress());
 				InetSocketAddress endpoint = new InetSocketAddress(bindAddr, Settings.getInstance().getApiPort());
 				this.server = new Server(endpoint);
 			}
@@ -230,4 +233,19 @@ public class ApiService {
 		this.server = null;
 	}
 
+	public static int getApiVersion(HttpServletRequest request) {
+		// Get API version
+		String apiVersionString = request.getHeader(API_VERSION_HEADER);
+		if (apiVersionString == null) {
+			// Try query string - this is needed to avoid a CORS preflight. See: https://stackoverflow.com/a/43881141
+			apiVersionString = request.getParameter("apiVersion");
+		}
+
+		int apiVersion = 1;
+		if (apiVersionString != null) {
+			apiVersion = Integer.parseInt(apiVersionString);
+		}
+		return apiVersion;
+	}
+
 }

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

@@ -3,7 +3,6 @@ package org.qortal.api;
 import io.swagger.v3.jaxrs2.integration.resources.OpenApiResource;
 import org.eclipse.jetty.http.HttpVersion;
 import org.eclipse.jetty.rewrite.handler.RewriteHandler;
-import org.eclipse.jetty.rewrite.handler.RewritePatternRule;
 import org.eclipse.jetty.server.*;
 import org.eclipse.jetty.server.handler.ErrorHandler;
 import org.eclipse.jetty.server.handler.InetAccessHandler;
@@ -16,6 +15,7 @@ import org.glassfish.jersey.server.ResourceConfig;
 import org.glassfish.jersey.servlet.ServletContainer;
 import org.qortal.api.resource.AnnotationPostProcessor;
 import org.qortal.api.resource.ApiDefinition;
+import org.qortal.network.Network;
 import org.qortal.settings.Settings;
 
 import javax.net.ssl.KeyManagerFactory;
@@ -38,7 +38,7 @@ public class DomainMapService {
 
 	private DomainMapService() {
 		this.config = new ResourceConfig();
-		this.config.packages("org.qortal.api.domainmap.resource");
+		this.config.packages("org.qortal.api.resource", "org.qortal.api.domainmap.resource");
 		this.config.register(OpenApiResource.class);
 		this.config.register(ApiDefinition.class);
 		this.config.register(AnnotationPostProcessor.class);
@@ -99,13 +99,13 @@ public class DomainMapService {
 				ServerConnector portUnifiedConnector = new ServerConnector(this.server,
 						new DetectorConnectionFactory(sslConnectionFactory),
 						httpConnectionFactory);
-				portUnifiedConnector.setHost(Settings.getInstance().getBindAddress());
+				portUnifiedConnector.setHost(Network.getInstance().getBindAddress());
 				portUnifiedConnector.setPort(Settings.getInstance().getDomainMapPort());
 
 				this.server.addConnector(portUnifiedConnector);
 			} else {
 				// Non-SSL
-				InetAddress bindAddr = InetAddress.getByName(Settings.getInstance().getBindAddress());
+				InetAddress bindAddr = InetAddress.getByName(Network.getInstance().getBindAddress());
 				InetSocketAddress endpoint = new InetSocketAddress(bindAddr, Settings.getInstance().getDomainMapPort());
 				this.server = new Server(endpoint);
 			}

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

@@ -15,6 +15,7 @@ import org.glassfish.jersey.server.ResourceConfig;
 import org.glassfish.jersey.servlet.ServletContainer;
 import org.qortal.api.resource.AnnotationPostProcessor;
 import org.qortal.api.resource.ApiDefinition;
+import org.qortal.network.Network;
 import org.qortal.settings.Settings;
 
 import javax.net.ssl.KeyManagerFactory;
@@ -37,7 +38,7 @@ public class GatewayService {
 
 	private GatewayService() {
 		this.config = new ResourceConfig();
-		this.config.packages("org.qortal.api.gateway.resource");
+		this.config.packages("org.qortal.api.resource", "org.qortal.api.gateway.resource");
 		this.config.register(OpenApiResource.class);
 		this.config.register(ApiDefinition.class);
 		this.config.register(AnnotationPostProcessor.class);
@@ -98,13 +99,13 @@ public class GatewayService {
 				ServerConnector portUnifiedConnector = new ServerConnector(this.server,
 						new DetectorConnectionFactory(sslConnectionFactory),
 						httpConnectionFactory);
-				portUnifiedConnector.setHost(Settings.getInstance().getBindAddress());
+				portUnifiedConnector.setHost(Network.getInstance().getBindAddress());
 				portUnifiedConnector.setPort(Settings.getInstance().getGatewayPort());
 
 				this.server.addConnector(portUnifiedConnector);
 			} else {
 				// Non-SSL
-				InetAddress bindAddr = InetAddress.getByName(Settings.getInstance().getBindAddress());
+				InetAddress bindAddr = InetAddress.getByName(Network.getInstance().getBindAddress());
 				InetSocketAddress endpoint = new InetSocketAddress(bindAddr, Settings.getInstance().getGatewayPort());
 				this.server = new Server(endpoint);
 			}

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

@@ -5,6 +5,9 @@ import org.apache.logging.log4j.Logger;
 import org.jsoup.Jsoup;
 import org.jsoup.nodes.Document;
 import org.jsoup.select.Elements;
+import org.qortal.arbitrary.misc.Service;
+
+import java.util.Objects;
 
 public class HTMLParser {
 
@@ -12,21 +15,52 @@ public class HTMLParser {
 
     private String linkPrefix;
     private byte[] data;
+    private String qdnContext;
+    private String resourceId;
+    private Service service;
+    private String identifier;
+    private String path;
+    private String theme;
 
-    public HTMLParser(String resourceId, String inPath, String prefix, boolean usePrefix, byte[] data) {
-        String inPathWithoutFilename = inPath.substring(0, inPath.lastIndexOf('/'));
-        this.linkPrefix = usePrefix ? String.format("%s/%s%s", prefix, resourceId, inPathWithoutFilename) : "";
+    public HTMLParser(String resourceId, String inPath, String prefix, boolean usePrefix, byte[] data,
+                      String qdnContext, Service service, String identifier, String theme) {
+        this.linkPrefix = usePrefix ? String.format("%s/%s", prefix, resourceId) : "";
         this.data = data;
+        this.qdnContext = qdnContext;
+        this.resourceId = resourceId;
+        this.service = service;
+        this.identifier = identifier;
+        this.path = inPath;
+        this.theme = theme;
     }
 
     public void addAdditionalHeaderTags() {
         String fileContents = new String(data);
         Document document = Jsoup.parse(fileContents);
-        String baseUrl = this.linkPrefix + "/";
+        String baseUrl = this.linkPrefix;
         Elements head = document.getElementsByTag("head");
         if (!head.isEmpty()) {
+            // Add q-apps script tag
+            String qAppsScriptElement = String.format("<script src=\"/apps/q-apps.js?time=%d\">", System.currentTimeMillis());
+            head.get(0).prepend(qAppsScriptElement);
+
+            // Add q-apps gateway script tag if in gateway mode
+            if (Objects.equals(this.qdnContext, "gateway")) {
+                String qAppsGatewayScriptElement = String.format("<script src=\"/apps/q-apps-gateway.js?time=%d\">", System.currentTimeMillis());
+                head.get(0).prepend(qAppsGatewayScriptElement);
+            }
+
+            // Escape and add vars
+            String service = this.service.toString().replace("\"","\\\"");
+            String name = this.resourceId != null ? this.resourceId.replace("\"","\\\"") : "";
+            String identifier = this.identifier != null ? this.identifier.replace("\"","\\\"") : "";
+            String path = this.path != null ? this.path.replace("\"","\\\"") : "";
+            String theme = this.theme != null ? this.theme.replace("\"","\\\"") : "";
+            String qdnContextVar = String.format("<script>var _qdnContext=\"%s\"; var _qdnTheme=\"%s\"; var _qdnService=\"%s\"; var _qdnName=\"%s\"; var _qdnIdentifier=\"%s\"; var _qdnPath=\"%s\"; var _qdnBase=\"%s\";</script>", this.qdnContext, theme, service, name, identifier, path, baseUrl);
+            head.get(0).prepend(qdnContextVar);
+
             // Add base href tag
-            String baseElement = String.format("<base href=\"%s\">", baseUrl);
+            String baseElement = String.format("<base href=\"%s/\">", baseUrl);
             head.get(0).prepend(baseElement);
 
             // Add meta charset tag

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

@@ -15,7 +15,21 @@ public abstract class Security {
 
 	public static final String API_KEY_HEADER = "X-API-KEY";
 
+	/**
+	 * Check API call is allowed, retrieving the API key from the request header or GET/POST parameters where required
+	 * @param request
+	 */
 	public static void checkApiCallAllowed(HttpServletRequest request) {
+		checkApiCallAllowed(request, null);
+	}
+
+	/**
+	 * Check API call is allowed, retrieving the API key first from the passedApiKey parameter, with a fallback
+	 * to the request header or GET/POST parameters when null.
+	 * @param request
+	 * @param passedApiKey - the API key to test, or null if it should be retrieved from the request headers.
+	 */
+	public static void checkApiCallAllowed(HttpServletRequest request, String passedApiKey) {
 		// We may want to allow automatic authentication for local requests, if enabled in settings
 		boolean localAuthBypassEnabled = Settings.getInstance().isLocalAuthBypassEnabled();
 		if (localAuthBypassEnabled) {
@@ -38,7 +52,10 @@ public abstract class Security {
 		}
 
 		// We require an API key to be passed
-		String passedApiKey = request.getHeader(API_KEY_HEADER);
+		if (passedApiKey == null) {
+			// API call not passed as a parameter, so try the header
+			passedApiKey = request.getHeader(API_KEY_HEADER);
+		}
 		if (passedApiKey == null) {
 			// Try query string - this is needed to avoid a CORS preflight. See: https://stackoverflow.com/a/43881141
 			passedApiKey = request.getParameter("apiKey");
@@ -56,7 +73,7 @@ public abstract class Security {
 	public static void disallowLoopbackRequests(HttpServletRequest request) {
 		try {
 			InetAddress remoteAddr = InetAddress.getByName(request.getRemoteAddr());
-			if (remoteAddr.isLoopbackAddress()) {
+			if (remoteAddr.isLoopbackAddress() && !Settings.getInstance().isGatewayLoopbackEnabled()) {
 				throw ApiExceptionFactory.INSTANCE.createCustomException(request, ApiError.UNAUTHORIZED, "Local requests not allowed");
 			}
 		} catch (UnknownHostException e) {
@@ -84,9 +101,9 @@ public abstract class Security {
 		}
 	}
 
-	public static void requirePriorAuthorizationOrApiKey(HttpServletRequest request, String resourceId, Service service, String identifier) {
+	public static void requirePriorAuthorizationOrApiKey(HttpServletRequest request, String resourceId, Service service, String identifier, String apiKey) {
 		try {
-			Security.checkApiCallAllowed(request);
+			Security.checkApiCallAllowed(request, apiKey);
 
 		} catch (ApiException e) {
 			// API call wasn't allowed, but maybe it was pre-authorized

src/main/java/org/qortal/api/domainmap/resource/DomainMapResource.java

@@ -42,16 +42,16 @@ public class DomainMapResource {
             // Build synchronously, so that we don't need to make the summary API endpoints available over
             // the domain map server. This means that there will be no loading screen, but this is potentially
             // preferred in this situation anyway (e.g. to avoid confusing search engine robots).
-            return this.get(domainMap.get(request.getServerName()), ResourceIdType.NAME, Service.WEBSITE, inPath, null, "", false, false);
+            return this.get(domainMap.get(request.getServerName()), ResourceIdType.NAME, Service.WEBSITE, null, inPath, null, "", false, false);
         }
         return ArbitraryDataRenderer.getResponse(response, 404, "Error 404: File Not Found");
     }
 
-    private HttpServletResponse get(String resourceId, ResourceIdType resourceIdType, Service service, String inPath,
-                                    String secret58, String prefix, boolean usePrefix, boolean async) {
+    private HttpServletResponse get(String resourceId, ResourceIdType resourceIdType, Service service, String identifier,
+                                    String inPath, String secret58, String prefix, boolean usePrefix, boolean async) {
 
-        ArbitraryDataRenderer renderer = new ArbitraryDataRenderer(resourceId, resourceIdType, service, inPath,
-                secret58, prefix, usePrefix, async, request, response, context);
+        ArbitraryDataRenderer renderer = new ArbitraryDataRenderer(resourceId, resourceIdType, service, identifier, inPath,
+                secret58, prefix, usePrefix, async, "domainMap", request, response, context);
         return renderer.render();
     }
 

src/main/java/org/qortal/api/gateway/resource/GatewayResource.java

@@ -2,6 +2,7 @@ package org.qortal.api.gateway.resource;
 
 import io.swagger.v3.oas.annotations.security.SecurityRequirement;
 import io.swagger.v3.oas.annotations.tags.Tag;
+import org.apache.commons.lang3.StringUtils;
 import org.qortal.api.Security;
 import org.qortal.arbitrary.ArbitraryDataFile;
 import org.qortal.arbitrary.ArbitraryDataFile.ResourceIdType;
@@ -16,6 +17,10 @@ import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 import javax.ws.rs.*;
 import javax.ws.rs.core.Context;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.LinkedList;
+import java.util.List;
 
 
 @Path("/")
@@ -76,50 +81,83 @@ public class GatewayResource {
 
 
     @GET
-    @Path("{name}/{path:.*}")
+    @Path("{path:.*}")
     @SecurityRequirement(name = "apiKey")
-    public HttpServletResponse getPathByName(@PathParam("name") String name,
-                                             @PathParam("path") String inPath) {
+    public HttpServletResponse getPath(@PathParam("path") String inPath) {
         // Block requests from localhost, to prevent websites/apps from running javascript that fetches unvetted data
         Security.disallowLoopbackRequests(request);
-        return this.get(name, ResourceIdType.NAME, Service.WEBSITE, inPath, null, "", true, true);
-    }
-
-    @GET
-    @Path("{name}")
-    @SecurityRequirement(name = "apiKey")
-    public HttpServletResponse getIndexByName(@PathParam("name") String name) {
-        // Block requests from localhost, to prevent websites/apps from running javascript that fetches unvetted data
-        Security.disallowLoopbackRequests(request);
-        return this.get(name, ResourceIdType.NAME, Service.WEBSITE, "/", null, "", true, true);
-    }
-
-
-    // Optional /site alternative for backwards support
-
-    @GET
-    @Path("/site/{name}/{path:.*}")
-    public HttpServletResponse getSitePathByName(@PathParam("name") String name,
-                                                 @PathParam("path") String inPath) {
-        // Block requests from localhost, to prevent websites/apps from running javascript that fetches unvetted data
-        Security.disallowLoopbackRequests(request);
-        return this.get(name, ResourceIdType.NAME, Service.WEBSITE, inPath, null, "/site", true, true);
-    }
-
-    @GET
-    @Path("/site/{name}")
-    public HttpServletResponse getSiteIndexByName(@PathParam("name") String name) {
-        // Block requests from localhost, to prevent websites/apps from running javascript that fetches unvetted data
-        Security.disallowLoopbackRequests(request);
-        return this.get(name, ResourceIdType.NAME, Service.WEBSITE, "/", null, "/site", true, true);
+        return this.parsePath(inPath, "gateway", null, true, true);
     }
 
     
-    private HttpServletResponse get(String resourceId, ResourceIdType resourceIdType, Service service, String inPath,
-                                    String secret58, String prefix, boolean usePrefix, boolean async) {
+    private HttpServletResponse parsePath(String inPath, String qdnContext, String secret58, boolean usePrefix, boolean async) {
 
-        ArbitraryDataRenderer renderer = new ArbitraryDataRenderer(resourceId, resourceIdType, service, inPath,
-                secret58, prefix, usePrefix, async, request, response, context);
+        if (inPath == null || inPath.equals("")) {
+            // Assume not a real file
+            return ArbitraryDataRenderer.getResponse(response, 404, "Error 404: File Not Found");
+        }
+
+        // Default service is WEBSITE
+        Service service = Service.WEBSITE;
+        String name = null;
+        String identifier = null;
+        String outPath = "";
+        List<String> prefixParts = new ArrayList<>();
+
+        if (!inPath.contains("/")) {
+            // Assume entire inPath is a registered name
+            name = inPath;
+        }
+        else {
+            // Parse the path to determine what we need to load
+            List<String> parts = new LinkedList<>(Arrays.asList(inPath.split("/")));
+
+            // Check if the first element is a service
+            try {
+                Service parsedService = Service.valueOf(parts.get(0).toUpperCase());
+                if (parsedService != null) {
+                    // First element matches a service, so we can assume it is one
+                    service = parsedService;
+                    parts.remove(0);
+                    prefixParts.add(service.name());
+                }
+            } catch (IllegalArgumentException e) {
+                // Not a service
+            }
+
+            if (parts.isEmpty()) {
+                // We need more than just a service
+                return ArbitraryDataRenderer.getResponse(response, 404, "Error 404: File Not Found");
+            }
+
+            // Service is removed, so assume first element is now a registered name
+            name = parts.get(0);
+            parts.remove(0);
+
+            if (!parts.isEmpty()) {
+                // Name is removed, so check if the first element is now an identifier
+                ArbitraryResourceStatus status = this.getStatus(service, name, parts.get(0), false);
+                if (status.getTotalChunkCount() > 0) {
+                    // Matched service, name and identifier combination - so assume this is an identifier and can be removed
+                    identifier = parts.get(0);
+                    parts.remove(0);
+                    prefixParts.add(identifier);
+                }
+            }
+
+            if (!parts.isEmpty()) {
+                // outPath can be built by combining any remaining parts
+                outPath = String.join("/", parts);
+            }
+        }
+
+        String prefix = StringUtils.join(prefixParts, "/");
+        if (prefix != null && prefix.length() > 0) {
+            prefix = "/" + prefix;
+        }
+
+        ArbitraryDataRenderer renderer = new ArbitraryDataRenderer(name, ResourceIdType.NAME, service, identifier, outPath,
+                secret58, prefix, usePrefix, async, qdnContext, request, response, context);
         return renderer.render();
     }
 

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

@@ -1,6 +1,7 @@
 package org.qortal.api.model;
 
 import io.swagger.v3.oas.annotations.media.Schema;
+import org.qortal.controller.Controller;
 import org.qortal.data.block.BlockSummaryData;
 import org.qortal.data.network.PeerData;
 import org.qortal.network.Handshake;
@@ -36,6 +37,7 @@ public class ConnectedPeer {
     public Long lastBlockTimestamp;
     public UUID connectionId;
     public String age;
+    public Boolean isTooDivergent;
 
     protected ConnectedPeer() {
     }
@@ -69,6 +71,11 @@ public class ConnectedPeer {
             this.lastBlockSignature = peerChainTipData.getSignature();
             this.lastBlockTimestamp = peerChainTipData.getTimestamp();
         }
+
+        // Only include isTooDivergent decision if we've had the opportunity to request block summaries this peer
+        if (peer.getLastTooDivergentTime() != null) {
+            this.isTooDivergent = Controller.wasRecentlyTooDivergent.test(peer);
+        }
     }
 
 }

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

@@ -0,0 +1,16 @@
+package org.qortal.api.model;
+
+import javax.xml.bind.annotation.XmlAccessType;
+import javax.xml.bind.annotation.XmlAccessorType;
+
+@XmlAccessorType(XmlAccessType.FIELD)
+public class FileProperties {
+
+	public String filename;
+	public String mimeType;
+	public Long size;
+
+	public FileProperties() {
+	}
+
+}

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

@@ -0,0 +1,83 @@
+package org.qortal.api.resource;
+
+import com.google.common.io.Resources;
+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.Hidden;
+import io.swagger.v3.oas.annotations.tags.Tag;
+import org.qortal.api.*;
+
+import javax.servlet.ServletContext;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import javax.ws.rs.*;
+import javax.ws.rs.core.Context;
+import javax.ws.rs.core.MediaType;
+import java.io.IOException;
+import java.net.URL;
+import java.nio.charset.StandardCharsets;
+
+
+@Path("/apps")
+@Tag(name = "Apps")
+public class AppsResource {
+
+    @Context HttpServletRequest request;
+    @Context HttpServletResponse response;
+    @Context ServletContext context;
+
+    @GET
+    @Path("/q-apps.js")
+    @Hidden // For internal Q-App API use only
+    @Operation(
+            summary = "Javascript interface for Q-Apps",
+            responses = {
+                    @ApiResponse(
+                            description = "javascript",
+                            content = @Content(
+                                    mediaType = MediaType.TEXT_PLAIN,
+                                    schema = @Schema(
+                                            type = "string"
+                                    )
+                            )
+                    )
+            }
+    )
+    public String getQAppsJs() {
+        URL url = Resources.getResource("q-apps/q-apps.js");
+        try {
+            return Resources.toString(url, StandardCharsets.UTF_8);
+        } catch (IOException e) {
+            throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FILE_NOT_FOUND);
+        }
+    }
+
+    @GET
+    @Path("/q-apps-gateway.js")
+    @Hidden // For internal Q-App API use only
+    @Operation(
+            summary = "Gateway-specific interface for Q-Apps",
+            responses = {
+                    @ApiResponse(
+                            description = "javascript",
+                            content = @Content(
+                                    mediaType = MediaType.TEXT_PLAIN,
+                                    schema = @Schema(
+                                            type = "string"
+                                    )
+                            )
+                    )
+            }
+    )
+    public String getQAppsGatewayJs() {
+        URL url = Resources.getResource("q-apps/q-apps-gateway.js");
+        try {
+            return Resources.toString(url, StandardCharsets.UTF_8);
+        } catch (IOException e) {
+            throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FILE_NOT_FOUND);
+        }
+    }
+
+}

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

@@ -1,6 +1,8 @@
 package org.qortal.api.resource;
 
 import com.google.common.primitives.Bytes;
+import com.j256.simplemagic.ContentInfo;
+import com.j256.simplemagic.ContentInfoUtil;
 import io.swagger.v3.oas.annotations.Operation;
 import io.swagger.v3.oas.annotations.Parameter;
 import io.swagger.v3.oas.annotations.media.ArraySchema;
@@ -12,11 +14,14 @@ import io.swagger.v3.oas.annotations.security.SecurityRequirement;
 import io.swagger.v3.oas.annotations.tags.Tag;
 
 import java.io.*;
+import java.net.FileNameMap;
+import java.net.URLConnection;
 import java.nio.file.Files;
 import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
+import java.util.Objects;
 
 import javax.servlet.ServletContext;
 import javax.servlet.http.HttpServletRequest;
@@ -25,11 +30,13 @@ import javax.ws.rs.*;
 import javax.ws.rs.core.Context;
 import javax.ws.rs.core.MediaType;
 
+import org.apache.commons.io.FileUtils;
 import org.apache.commons.lang3.ArrayUtils;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.bouncycastle.util.encoders.Base64;
 import org.qortal.api.*;
+import org.qortal.api.model.FileProperties;
 import org.qortal.api.resource.TransactionsResource.ConfirmationStatus;
 import org.qortal.arbitrary.*;
 import org.qortal.arbitrary.ArbitraryDataFile.ResourceIdType;
@@ -38,6 +45,7 @@ import org.qortal.arbitrary.metadata.ArbitraryDataTransactionMetadata;
 import org.qortal.arbitrary.misc.Category;
 import org.qortal.arbitrary.misc.Service;
 import org.qortal.controller.Controller;
+import org.qortal.controller.arbitrary.ArbitraryDataRenderManager;
 import org.qortal.controller.arbitrary.ArbitraryDataStorageManager;
 import org.qortal.controller.arbitrary.ArbitraryMetadataManager;
 import org.qortal.data.account.AccountData;
@@ -88,12 +96,15 @@ public class ArbitraryResource {
 	@ApiErrors({ApiError.REPOSITORY_ISSUE})
 	public List<ArbitraryResourceInfo> getResources(
 			@QueryParam("service") Service service,
+			@QueryParam("name") String name,
 			@QueryParam("identifier") String identifier,
 			@Parameter(description = "Default resources (without identifiers) only") @QueryParam("default") Boolean defaultResource,
 			@Parameter(ref = "limit") @QueryParam("limit") Integer limit,
 			@Parameter(ref = "offset") @QueryParam("offset") Integer offset,
 			@Parameter(ref = "reverse") @QueryParam("reverse") Boolean reverse,
-			@Parameter(description = "Filter names by list") @QueryParam("namefilter") String nameFilter,
+			@Parameter(description = "Include followed names only") @QueryParam("followedonly") Boolean followedOnly,
+			@Parameter(description = "Exclude blocked content") @QueryParam("excludeblocked") Boolean excludeBlocked,
+			@Parameter(description = "Filter names by list") @QueryParam("namefilter") String nameListFilter,
 			@Parameter(description = "Include status") @QueryParam("includestatus") Boolean includeStatus,
 			@Parameter(description = "Include metadata") @QueryParam("includemetadata") Boolean includeMetadata) {
 
@@ -110,28 +121,33 @@ public class ArbitraryResource {
 				throw ApiExceptionFactory.INSTANCE.createCustomException(request, ApiError.INVALID_CRITERIA, "identifier cannot be specified when requesting a default resource");
 			}
 
-			// Load filter from list if needed
+			// Set up name filters if supplied
 			List<String> names = null;
-			if (nameFilter != null) {
-				names = ResourceListManager.getInstance().getStringsInList(nameFilter);
+			if (name != null) {
+				// Filter using single name
+				names = Arrays.asList(name);
+			}
+			else if (nameListFilter != null) {
+				// Filter using supplied list of names
+				names = ResourceListManager.getInstance().getStringsInList(nameListFilter);
 				if (names.isEmpty()) {
-					// List doesn't exist or is empty - so there will be no matches
+					// If list is empty (or doesn't exist) we can shortcut with empty response
 					return new ArrayList<>();
 				}
 			}
 
 			List<ArbitraryResourceInfo> resources = repository.getArbitraryRepository()
-					.getArbitraryResources(service, identifier, names, defaultRes, limit, offset, reverse);
+					.getArbitraryResources(service, identifier, names, defaultRes, followedOnly, excludeBlocked, limit, offset, reverse);
 
 			if (resources == null) {
 				return new ArrayList<>();
 			}
 
 			if (includeStatus != null && includeStatus) {
-				resources = this.addStatusToResources(resources);
+				resources = ArbitraryTransactionUtils.addStatusToResources(resources);
 			}
 			if (includeMetadata != null && includeMetadata) {
-				resources = this.addMetadataToResources(resources);
+				resources = ArbitraryTransactionUtils.addMetadataToResources(resources);
 			}
 
 			return resources;
@@ -155,30 +171,49 @@ public class ArbitraryResource {
 	@ApiErrors({ApiError.REPOSITORY_ISSUE})
 	public List<ArbitraryResourceInfo> searchResources(
 			@QueryParam("service") Service service,
-			@QueryParam("query") String query,
+			@Parameter(description = "Query (searches both name and identifier fields)") @QueryParam("query") String query,
+			@Parameter(description = "Identifier (searches identifier field only)") @QueryParam("identifier") String identifier,
+			@Parameter(description = "Name (searches name field only)") @QueryParam("name") List<String> names,
+			@Parameter(description = "Prefix only (if true, only the beginning of fields are matched)") @QueryParam("prefix") Boolean prefixOnly,
 			@Parameter(description = "Default resources (without identifiers) only") @QueryParam("default") Boolean defaultResource,
+			@Parameter(description = "Filter names by list (exact matches only)") @QueryParam("namefilter") String nameListFilter,
+			@Parameter(description = "Include followed names only") @QueryParam("followedonly") Boolean followedOnly,
+			@Parameter(description = "Exclude blocked content") @QueryParam("excludeblocked") Boolean excludeBlocked,
+			@Parameter(description = "Include status") @QueryParam("includestatus") Boolean includeStatus,
+			@Parameter(description = "Include metadata") @QueryParam("includemetadata") Boolean includeMetadata,
 			@Parameter(ref = "limit") @QueryParam("limit") Integer limit,
 			@Parameter(ref = "offset") @QueryParam("offset") Integer offset,
-			@Parameter(ref = "reverse") @QueryParam("reverse") Boolean reverse,
-			@Parameter(description = "Include status") @QueryParam("includestatus") Boolean includeStatus,
-			@Parameter(description = "Include metadata") @QueryParam("includemetadata") Boolean includeMetadata) {
+			@Parameter(ref = "reverse") @QueryParam("reverse") Boolean reverse) {
 
 		try (final Repository repository = RepositoryManager.getRepository()) {
 
 			boolean defaultRes = Boolean.TRUE.equals(defaultResource);
+			boolean usePrefixOnly = Boolean.TRUE.equals(prefixOnly);
+
+			List<String> exactMatchNames = new ArrayList<>();
+
+			if (nameListFilter != null) {
+				// Load names from supplied list of names
+				exactMatchNames.addAll(ResourceListManager.getInstance().getStringsInList(nameListFilter));
+
+				// If list is empty (or doesn't exist) we can shortcut with empty response
+				if (exactMatchNames.isEmpty()) {
+					return new ArrayList<>();
+				}
+			}
 
 			List<ArbitraryResourceInfo> resources = repository.getArbitraryRepository()
-					.searchArbitraryResources(service, query, defaultRes, limit, offset, reverse);
+					.searchArbitraryResources(service, query, identifier, names, usePrefixOnly, exactMatchNames, defaultRes, followedOnly, excludeBlocked, limit, offset, reverse);
 
 			if (resources == null) {
 				return new ArrayList<>();
 			}
 
 			if (includeStatus != null && includeStatus) {
-				resources = this.addStatusToResources(resources);
+				resources = ArbitraryTransactionUtils.addStatusToResources(resources);
 			}
 			if (includeMetadata != null && includeMetadata) {
-				resources = this.addMetadataToResources(resources);
+				resources = ArbitraryTransactionUtils.addMetadataToResources(resources);
 			}
 
 			return resources;
@@ -188,67 +223,6 @@ public class ArbitraryResource {
 		}
 	}
 
-	@GET
-	@Path("/resources/names")
-	@Operation(
-			summary = "List arbitrary resources available on chain, grouped by creator's name",
-			responses = {
-					@ApiResponse(
-							content = @Content(mediaType = MediaType.APPLICATION_JSON, schema = @Schema(implementation = ArbitraryResourceInfo.class))
-					)
-			}
-	)
-	@ApiErrors({ApiError.REPOSITORY_ISSUE})
-	public List<ArbitraryResourceNameInfo> getResourcesGroupedByName(
-			@QueryParam("service") Service service,
-			@QueryParam("identifier") String identifier,
-			@Parameter(description = "Default resources (without identifiers) only") @QueryParam("default") Boolean defaultResource,
-			@Parameter(ref = "limit") @QueryParam("limit") Integer limit,
-			@Parameter(ref = "offset") @QueryParam("offset") Integer offset,
-			@Parameter(ref = "reverse") @QueryParam("reverse") Boolean reverse,
-			@Parameter(description = "Include status") @QueryParam("includestatus") Boolean includeStatus,
-			@Parameter(description = "Include metadata") @QueryParam("includemetadata") Boolean includeMetadata) {
-
-		try (final Repository repository = RepositoryManager.getRepository()) {
-
-			// Treat empty identifier as null
-			if (identifier != null && identifier.isEmpty()) {
-				identifier = null;
-			}
-
-			// Ensure that "default" and "identifier" parameters cannot coexist
-			boolean defaultRes = Boolean.TRUE.equals(defaultResource);
-			if (defaultRes == true && identifier != null) {
-				throw ApiExceptionFactory.INSTANCE.createCustomException(request, ApiError.INVALID_CRITERIA, "identifier cannot be specified when requesting a default resource");
-			}
-
-			List<ArbitraryResourceNameInfo> creatorNames = repository.getArbitraryRepository()
-					.getArbitraryResourceCreatorNames(service, identifier, defaultRes, limit, offset, reverse);
-
-			for (ArbitraryResourceNameInfo creatorName : creatorNames) {
-				String name = creatorName.name;
-				if (name != null) {
-					List<ArbitraryResourceInfo> resources = repository.getArbitraryRepository()
-							.getArbitraryResources(service, identifier, Arrays.asList(name), defaultRes, null, null, reverse);
-
-					if (includeStatus != null && includeStatus) {
-						resources = this.addStatusToResources(resources);
-					}
-					if (includeMetadata != null && includeMetadata) {
-						resources = this.addMetadataToResources(resources);
-					}
-
-					creatorName.resources = resources;
-				}
-			}
-
-			return creatorNames;
-
-		} catch (DataException e) {
-			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
-		}
-	}
-
 	@GET
 	@Path("/resource/status/{service}/{name}")
 	@Operation(
@@ -266,10 +240,35 @@ public class ArbitraryResource {
 															@PathParam("name") String name,
 															@QueryParam("build") Boolean build) {
 
-		Security.requirePriorAuthorizationOrApiKey(request, name, service, null);
+		if (!Settings.getInstance().isQDNAuthBypassEnabled())
+			Security.requirePriorAuthorizationOrApiKey(request, name, service, null, apiKey);
+
 		return ArbitraryTransactionUtils.getStatus(service, name, null, build);
 	}
 
+	@GET
+	@Path("/resource/properties/{service}/{name}/{identifier}")
+	@Operation(
+			summary = "Get properties of a QDN resource",
+			description = "This attempts a download of the data if it's not available locally. A filename will only be returned for single file resources. mimeType is only returned when it can be determined.",
+			responses = {
+					@ApiResponse(
+							content = @Content(mediaType = MediaType.APPLICATION_JSON, schema = @Schema(implementation = FileProperties.class))
+					)
+			}
+	)
+	@SecurityRequirement(name = "apiKey")
+	public FileProperties getResourceProperties(@HeaderParam(Security.API_KEY_HEADER) String apiKey,
+											  @PathParam("service") Service service,
+											  @PathParam("name") String name,
+											  @PathParam("identifier") String identifier) {
+
+		if (!Settings.getInstance().isQDNAuthBypassEnabled())
+			Security.requirePriorAuthorizationOrApiKey(request, name, service, identifier, apiKey);
+
+		return this.getFileProperties(service, name, identifier);
+	}
+
 	@GET
 	@Path("/resource/status/{service}/{name}/{identifier}")
 	@Operation(
@@ -288,7 +287,9 @@ public class ArbitraryResource {
 													 @PathParam("identifier") String identifier,
 													 @QueryParam("build") Boolean build) {
 
-		Security.requirePriorAuthorizationOrApiKey(request, name, service, identifier);
+		if (!Settings.getInstance().isQDNAuthBypassEnabled())
+			Security.requirePriorAuthorizationOrApiKey(request, name, service, identifier, apiKey);
+
 		return ArbitraryTransactionUtils.getStatus(service, name, identifier, build);
 	}
 
@@ -501,6 +502,9 @@ public class ArbitraryResource {
 			}
 
 			for (ArbitraryTransactionData transactionData : transactionDataList) {
+				if (transactionData.getService() == null) {
+					continue;
+				}
 				ArbitraryResourceInfo arbitraryResourceInfo = new ArbitraryResourceInfo();
 				arbitraryResourceInfo.name = transactionData.getName();
 				arbitraryResourceInfo.service = transactionData.getService();
@@ -511,10 +515,10 @@ public class ArbitraryResource {
 			}
 
 			if (includeStatus != null && includeStatus) {
-				resources = this.addStatusToResources(resources);
+				resources = ArbitraryTransactionUtils.addStatusToResources(resources);
 			}
 			if (includeMetadata != null && includeMetadata) {
-				resources = this.addMetadataToResources(resources);
+				resources = ArbitraryTransactionUtils.addMetadataToResources(resources);
 			}
 
 			return resources;
@@ -544,7 +548,7 @@ public class ArbitraryResource {
 
 		Security.checkApiCallAllowed(request);
 		ArbitraryDataResource resource = new ArbitraryDataResource(name, ResourceIdType.NAME, service, identifier);
-		return resource.delete();
+		return resource.delete(false);
 	}
 
 	@POST
@@ -641,6 +645,7 @@ public class ArbitraryResource {
 								   @PathParam("service") Service service,
 								   @PathParam("name") String name,
 								   @QueryParam("filepath") String filepath,
+								   @QueryParam("encoding") String encoding,
 								   @QueryParam("rebuild") boolean rebuild,
 								   @QueryParam("async") boolean async,
 								   @QueryParam("attempts") Integer attempts) {
@@ -650,7 +655,7 @@ public class ArbitraryResource {
 			Security.checkApiCallAllowed(request);
 		}
 
-		return this.download(service, name, null, filepath, rebuild, async, attempts);
+		return this.download(service, name, null, filepath, encoding, rebuild, async, attempts);
 	}
 
 	@GET
@@ -676,16 +681,17 @@ public class ArbitraryResource {
 								   @PathParam("name") String name,
 								   @PathParam("identifier") String identifier,
 								   @QueryParam("filepath") String filepath,
+								   @QueryParam("encoding") String encoding,
 								   @QueryParam("rebuild") boolean rebuild,
 								   @QueryParam("async") boolean async,
 								   @QueryParam("attempts") Integer attempts) {
 
 		// Authentication can be bypassed in the settings, for those running public QDN nodes
 		if (!Settings.getInstance().isQDNAuthBypassEnabled()) {
-			Security.checkApiCallAllowed(request);
+			Security.checkApiCallAllowed(request, apiKey);
 		}
 
-		return this.download(service, name, identifier, filepath, rebuild, async, attempts);
+		return this.download(service, name, identifier, filepath, encoding, rebuild, async, attempts);
 	}
 
 
@@ -719,7 +725,7 @@ public class ArbitraryResource {
 		try {
 			ArbitraryDataTransactionMetadata transactionMetadata = ArbitraryMetadataManager.getInstance().fetchMetadata(resource, false);
 			if (transactionMetadata != null) {
-				ArbitraryResourceMetadata resourceMetadata = ArbitraryResourceMetadata.fromTransactionMetadata(transactionMetadata);
+				ArbitraryResourceMetadata resourceMetadata = ArbitraryResourceMetadata.fromTransactionMetadata(transactionMetadata, true);
 				if (resourceMetadata != null) {
 					return resourceMetadata;
 				}
@@ -733,7 +739,7 @@ public class ArbitraryResource {
 			throw ApiExceptionFactory.INSTANCE.createCustomException(request, ApiError.FILE_NOT_FOUND, e.getMessage());
 		}
 
-		throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_DATA);
+		throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FILE_NOT_FOUND);
 	}
 
 
@@ -773,6 +779,8 @@ public class ArbitraryResource {
 					   @QueryParam("description") String description,
 					   @QueryParam("tags") List<String> tags,
 					   @QueryParam("category") Category category,
+					   @QueryParam("fee") Long fee,
+					   @QueryParam("preview") Boolean preview,
 					   String path) {
 		Security.checkApiCallAllowed(request);
 
@@ -781,7 +789,7 @@ public class ArbitraryResource {
 		}
 
 		return this.upload(Service.valueOf(serviceString), name, null, path, null, null, false,
-				title, description, tags, category);
+				fee, null, title, description, tags, category, preview);
 	}
 
 	@POST
@@ -818,6 +826,8 @@ public class ArbitraryResource {
 					   @QueryParam("description") String description,
 					   @QueryParam("tags") List<String> tags,
 					   @QueryParam("category") Category category,
+					   @QueryParam("fee") Long fee,
+					   @QueryParam("preview") Boolean preview,
 					   String path) {
 		Security.checkApiCallAllowed(request);
 
@@ -826,7 +836,7 @@ public class ArbitraryResource {
 		}
 
 		return this.upload(Service.valueOf(serviceString), name, identifier, path, null, null, false,
-				title, description, tags, category);
+				fee, null, title, description, tags, category, preview);
 	}
 
 
@@ -864,6 +874,9 @@ public class ArbitraryResource {
 										@QueryParam("description") String description,
 										@QueryParam("tags") List<String> tags,
 										@QueryParam("category") Category category,
+										@QueryParam("filename") String filename,
+										@QueryParam("fee") Long fee,
+										@QueryParam("preview") Boolean preview,
 										String base64) {
 		Security.checkApiCallAllowed(request);
 
@@ -872,7 +885,7 @@ public class ArbitraryResource {
 		}
 
 		return this.upload(Service.valueOf(serviceString), name, null, null, null, base64, false,
-				title, description, tags, category);
+				fee, filename, title, description, tags, category, preview);
 	}
 
 	@POST
@@ -907,6 +920,9 @@ public class ArbitraryResource {
 										@QueryParam("description") String description,
 										@QueryParam("tags") List<String> tags,
 										@QueryParam("category") Category category,
+										@QueryParam("filename") String filename,
+										@QueryParam("fee") Long fee,
+										@QueryParam("preview") Boolean preview,
 										String base64) {
 		Security.checkApiCallAllowed(request);
 
@@ -915,7 +931,7 @@ public class ArbitraryResource {
 		}
 
 		return this.upload(Service.valueOf(serviceString), name, identifier, null, null, base64, false,
-				title, description, tags, category);
+				fee, filename, title, description, tags, category, preview);
 	}
 
 
@@ -952,6 +968,8 @@ public class ArbitraryResource {
 								 @QueryParam("description") String description,
 								 @QueryParam("tags") List<String> tags,
 								 @QueryParam("category") Category category,
+								 @QueryParam("fee") Long fee,
+								 @QueryParam("preview") Boolean preview,
 								 String base64Zip) {
 		Security.checkApiCallAllowed(request);
 
@@ -960,7 +978,7 @@ public class ArbitraryResource {
 		}
 
 		return this.upload(Service.valueOf(serviceString), name, null, null, null, base64Zip, true,
-				title, description, tags, category);
+				fee, null, title, description, tags, category, preview);
 	}
 
 	@POST
@@ -995,6 +1013,8 @@ public class ArbitraryResource {
 								 @QueryParam("description") String description,
 								 @QueryParam("tags") List<String> tags,
 								 @QueryParam("category") Category category,
+								 @QueryParam("fee") Long fee,
+								 @QueryParam("preview") Boolean preview,
 								 String base64Zip) {
 		Security.checkApiCallAllowed(request);
 
@@ -1003,7 +1023,7 @@ public class ArbitraryResource {
 		}
 
 		return this.upload(Service.valueOf(serviceString), name, identifier, null, null, base64Zip, true,
-				title, description, tags, category);
+				fee, null, title, description, tags, category, preview);
 	}
 
 
@@ -1043,6 +1063,9 @@ public class ArbitraryResource {
 							 @QueryParam("description") String description,
 							 @QueryParam("tags") List<String> tags,
 							 @QueryParam("category") Category category,
+							 @QueryParam("filename") String filename,
+							 @QueryParam("fee") Long fee,
+							 @QueryParam("preview") Boolean preview,
 							 String string) {
 		Security.checkApiCallAllowed(request);
 
@@ -1051,7 +1074,7 @@ public class ArbitraryResource {
 		}
 
 		return this.upload(Service.valueOf(serviceString), name, null, null, string, null, false,
-				title, description, tags, category);
+				fee, filename, title, description, tags, category, preview);
 	}
 
 	@POST
@@ -1088,6 +1111,9 @@ public class ArbitraryResource {
 							 @QueryParam("description") String description,
 							 @QueryParam("tags") List<String> tags,
 							 @QueryParam("category") Category category,
+							 @QueryParam("filename") String filename,
+							 @QueryParam("fee") Long fee,
+							 @QueryParam("preview") Boolean preview,
 							 String string) {
 		Security.checkApiCallAllowed(request);
 
@@ -1096,15 +1122,48 @@ public class ArbitraryResource {
 		}
 
 		return this.upload(Service.valueOf(serviceString), name, identifier, null, string, null, false,
-				title, description, tags, category);
+				fee, filename, title, description, tags, category, preview);
 	}
 
 
 	// Shared methods
 
+	private String preview(String directoryPath, Service service) {
+		Security.checkApiCallAllowed(request);
+		ArbitraryTransactionData.Method method = ArbitraryTransactionData.Method.PUT;
+		ArbitraryTransactionData.Compression compression = ArbitraryTransactionData.Compression.ZIP;
+
+		ArbitraryDataWriter arbitraryDataWriter = new ArbitraryDataWriter(Paths.get(directoryPath),
+				null, service, null, method, compression,
+				null, null, null, null);
+		try {
+			arbitraryDataWriter.save();
+		} catch (IOException | DataException | InterruptedException | MissingDataException e) {
+			LOGGER.info("Unable to create arbitrary data file: {}", e.getMessage());
+			throw ApiExceptionFactory.INSTANCE.createCustomException(request, ApiError.REPOSITORY_ISSUE, e.getMessage());
+		} catch (RuntimeException e) {
+			LOGGER.info("Unable to create arbitrary data file: {}", e.getMessage());
+			throw ApiExceptionFactory.INSTANCE.createCustomException(request, ApiError.INVALID_DATA, e.getMessage());
+		}
+
+		ArbitraryDataFile arbitraryDataFile = arbitraryDataWriter.getArbitraryDataFile();
+		if (arbitraryDataFile != null) {
+			String digest58 = arbitraryDataFile.digest58();
+			if (digest58 != null) {
+				// Pre-authorize resource
+				ArbitraryDataResource resource = new ArbitraryDataResource(digest58, null, null, null);
+				ArbitraryDataRenderManager.getInstance().addToAuthorizedResources(resource);
+
+				return "/render/hash/" + digest58 + "?secret=" + Base58.encode(arbitraryDataFile.getSecret());
+			}
+		}
+		return "Unable to generate preview URL";
+	}
+
 	private String upload(Service service, String name, String identifier,
-						  String path, String string, String base64, boolean zipped,
-						  String title, String description, List<String> tags, Category category) {
+						  String path, String string, String base64, boolean zipped, Long fee, String filename,
+						  String title, String description, List<String> tags, Category category,
+						  Boolean preview) {
 		// Fetch public key from registered name
 		try (final Repository repository = RepositoryManager.getRepository()) {
 			NameData nameData = repository.getNameRepository().fromName(name);
@@ -1128,7 +1187,12 @@ public class ArbitraryResource {
 			if (path == null) {
 				// See if we have a string instead
 				if (string != null) {
-					File tempFile = File.createTempFile("qortal-", ".tmp");
+					if (filename == null) {
+						// Use current time as filename
+						filename = String.format("qortal-%d", NTP.getTime());
+					}
+					java.nio.file.Path tempDirectory = Files.createTempDirectory("qortal-");
+					File tempFile = Paths.get(tempDirectory.toString(), filename).toFile();
 					tempFile.deleteOnExit();
 					BufferedWriter writer = new BufferedWriter(new FileWriter(tempFile.toPath().toString()));
 					writer.write(string);
@@ -1138,7 +1202,12 @@ public class ArbitraryResource {
 				}
 				// ... or base64 encoded raw data
 				else if (base64 != null) {
-					File tempFile = File.createTempFile("qortal-", ".tmp");
+					if (filename == null) {
+						// Use current time as filename
+						filename = String.format("qortal-%d", NTP.getTime());
+					}
+					java.nio.file.Path tempDirectory = Files.createTempDirectory("qortal-");
+					File tempFile = Paths.get(tempDirectory.toString(), filename).toFile();
 					tempFile.deleteOnExit();
 					Files.write(tempFile.toPath(), Base64.decode(base64));
 					path = tempFile.toPath().toString();
@@ -1167,9 +1236,19 @@ public class ArbitraryResource {
 				}
 			}
 
+			// Finish here if user has requested a preview
+			if (preview != null && preview == true) {
+				return this.preview(path, service);
+			}
+
+			// Default to zero fee if not specified
+			if (fee == null) {
+				fee = 0L;
+			}
+
 			try {
 				ArbitraryDataTransactionBuilder transactionBuilder = new ArbitraryDataTransactionBuilder(
-						repository, publicKey58, Paths.get(path), name, null, service, identifier,
+						repository, publicKey58, fee, Paths.get(path), name, null, service, identifier,
 						title, description, tags, category
 				);
 
@@ -1188,7 +1267,7 @@ public class ArbitraryResource {
 		}
 	}
 
-	private HttpServletResponse download(Service service, String name, String identifier, String filepath, boolean rebuild, boolean async, Integer maxAttempts) {
+	private HttpServletResponse download(Service service, String name, String identifier, String filepath, String encoding, boolean rebuild, boolean async, Integer maxAttempts) {
 
 		ArbitraryDataReader arbitraryDataReader = new ArbitraryDataReader(name, ArbitraryDataFile.ResourceIdType.NAME, service, identifier);
 		try {
@@ -1247,7 +1326,14 @@ public class ArbitraryResource {
 				String message = String.format("No file exists at filepath: %s", filepath);
 				throw ApiExceptionFactory.INSTANCE.createCustomException(request, ApiError.INVALID_CRITERIA, message);
 			}
+
 			byte[] data = Files.readAllBytes(path);
+
+			// Encode the data if requested
+			if (encoding != null && Objects.equals(encoding.toLowerCase(), "base64")) {
+				data = Base64.encode(data);
+			}
+
 			response.setContentType(context.getMimeType(path.toString()));
 			response.setContentLength(data.length);
 			response.getOutputStream().write(data);
@@ -1259,41 +1345,44 @@ public class ArbitraryResource {
 		}
 	}
 
+	private FileProperties getFileProperties(Service service, String name, String identifier) {
+		ArbitraryDataReader arbitraryDataReader = new ArbitraryDataReader(name, ArbitraryDataFile.ResourceIdType.NAME, service, identifier);
+		try {
+			arbitraryDataReader.loadSynchronously(false);
+			java.nio.file.Path outputPath = arbitraryDataReader.getFilePath();
+			if (outputPath == null) {
+				// Assume the resource doesn't exist
+				throw ApiExceptionFactory.INSTANCE.createCustomException(request, ApiError.FILE_NOT_FOUND, "File not found");
+			}
 
-	private List<ArbitraryResourceInfo> addStatusToResources(List<ArbitraryResourceInfo> resources) {
-		// Determine and add the status of each resource
-		List<ArbitraryResourceInfo> updatedResources = new ArrayList<>();
-		for (ArbitraryResourceInfo resourceInfo : resources) {
-			try {
-				ArbitraryDataResource resource = new ArbitraryDataResource(resourceInfo.name, ResourceIdType.NAME,
-						resourceInfo.service, resourceInfo.identifier);
-				ArbitraryResourceStatus status = resource.getStatus(true);
-				if (status != null) {
-					resourceInfo.status = status;
+			FileProperties fileProperties = new FileProperties();
+			fileProperties.size = FileUtils.sizeOfDirectory(outputPath.toFile());
+
+			String[] files = ArrayUtils.removeElement(outputPath.toFile().list(), ".qortal");
+			if (files.length == 1) {
+				String filename = files[0];
+				java.nio.file.Path filePath = Paths.get(outputPath.toString(), files[0]);
+				ContentInfoUtil util = new ContentInfoUtil();
+				ContentInfo info = util.findMatch(filePath.toFile());
+				String mimeType;
+				if (info != null) {
+					// Attempt to extract MIME type from file contents
+					mimeType = info.getMimeType();
 				}
-				updatedResources.add(resourceInfo);
-
-			} catch (Exception e) {
-				// Catch and log all exceptions, since some systems are experiencing 500 errors when including statuses
-				LOGGER.info("Caught exception when adding status to resource %s: %s", resourceInfo, e.toString());
+				else {
+					// Fall back to using the filename
+					FileNameMap fileNameMap = URLConnection.getFileNameMap();
+					mimeType = fileNameMap.getContentTypeFor(filename);
+				}
+				fileProperties.filename = filename;
+				fileProperties.mimeType = mimeType;
 			}
-		}
-		return updatedResources;
-	}
 
-	private List<ArbitraryResourceInfo> addMetadataToResources(List<ArbitraryResourceInfo> resources) {
-		// Add metadata fields to each resource if they exist
-		List<ArbitraryResourceInfo> updatedResources = new ArrayList<>();
-		for (ArbitraryResourceInfo resourceInfo : resources) {
-			ArbitraryDataResource resource = new ArbitraryDataResource(resourceInfo.name, ResourceIdType.NAME,
-					resourceInfo.service, resourceInfo.identifier);
-			ArbitraryDataTransactionMetadata transactionMetadata = resource.getLatestTransactionMetadata();
-			ArbitraryResourceMetadata resourceMetadata = ArbitraryResourceMetadata.fromTransactionMetadata(transactionMetadata);
-			if (resourceMetadata != null) {
-				resourceInfo.metadata = resourceMetadata;
-			}
-			updatedResources.add(resourceInfo);
+			return fileProperties;
+
+		} catch (Exception e) {
+			LOGGER.debug(String.format("Unable to load %s %s: %s", service, name, e.getMessage()));
+			throw ApiExceptionFactory.INSTANCE.createCustomException(request, ApiError.FILE_NOT_FOUND, e.getMessage());
 		}
-		return updatedResources;
 	}
 }

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

@@ -48,6 +48,7 @@ import org.qortal.repository.RepositoryManager;
 import org.qortal.transform.TransformationException;
 import org.qortal.transform.block.BlockTransformer;
 import org.qortal.utils.Base58;
+import org.qortal.utils.Triple;
 
 @Path("/blocks")
 @Tag(name = "Blocks")
@@ -165,10 +166,13 @@ public class BlocksResource {
             }
 
             // Not found, so try the block archive
-            byte[] bytes = BlockArchiveReader.getInstance().fetchSerializedBlockBytesForSignature(signature, false, repository);
-            if (bytes != null) {
-				if (version != 1) {
-					throw ApiExceptionFactory.INSTANCE.createCustomException(request, ApiError.INVALID_CRITERIA, "Archived blocks require version 1");
+            Triple<byte[], Integer, Integer> serializedBlock = BlockArchiveReader.getInstance().fetchSerializedBlockBytesForSignature(signature, false, repository);
+            if (serializedBlock != null) {
+				byte[] bytes = serializedBlock.getA();
+				Integer serializationVersion = serializedBlock.getB();
+				if (version != serializationVersion) {
+					// TODO: we could quite easily reserialize the block with the requested version
+					throw ApiExceptionFactory.INSTANCE.createCustomException(request, ApiError.INVALID_CRITERIA, "Block is not stored using requested serialization version.");
 				}
 				return Base58.encode(bytes);
             }
@@ -634,13 +638,16 @@ public class BlocksResource {
 	@ApiErrors({
 		ApiError.REPOSITORY_ISSUE
 	})
-	public List<BlockData> getBlockRange(@PathParam("height") int height, @Parameter(
-		ref = "count"
-	) @QueryParam("count") int count) {
+	public List<BlockData> getBlockRange(@PathParam("height") int height,
+										 @Parameter(ref = "count") @QueryParam("count") int count,
+										 @Parameter(ref = "reverse") @QueryParam("reverse") Boolean reverse,
+										 @QueryParam("includeOnlineSignatures") Boolean includeOnlineSignatures) {
 		try (final Repository repository = RepositoryManager.getRepository()) {
 			List<BlockData> blocks = new ArrayList<>();
+			boolean shouldReverse = (reverse != null && reverse == true);
 
-			for (/* count already set */; count > 0; --count, ++height) {
+			int i = 0;
+			while (i < count) {
 				BlockData blockData = repository.getBlockRepository().fromHeight(height);
 				if (blockData == null) {
 					// Not found - try the archive
@@ -650,8 +657,14 @@ public class BlocksResource {
 						break;
 					}
 				}
+				if (includeOnlineSignatures == null || includeOnlineSignatures == false) {
+					blockData.setOnlineAccountsSignatures(null);
+				}
 
 				blocks.add(blockData);
+
+				height = shouldReverse ? height - 1 : height + 1;
+				i++;
 			}
 
 			return blocks;

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

@@ -40,6 +40,8 @@ import org.qortal.utils.Base58;
 
 import com.google.common.primitives.Bytes;
 
+import static org.qortal.data.chat.ChatMessage.Encoding;
+
 @Path("/chat")
 @Tag(name = "Chat")
 public class ChatResource {
@@ -70,6 +72,10 @@ public class ChatResource {
 			@QueryParam("txGroupId") Integer txGroupId,
 			@QueryParam("involving") List<String> involvingAddresses,
 			@QueryParam("reference") String reference,
+			@QueryParam("chatreference") String chatReference,
+			@QueryParam("haschatreference") Boolean hasChatReference,
+			@QueryParam("sender") String sender,
+			@QueryParam("encoding") Encoding encoding,
 			@Parameter(ref = "limit") @QueryParam("limit") Integer limit,
 			@Parameter(ref = "offset") @QueryParam("offset") Integer offset,
 			@Parameter(ref = "reverse") @QueryParam("reverse") Boolean reverse) {
@@ -92,13 +98,21 @@ public class ChatResource {
 		if (reference != null)
 			referenceBytes = Base58.decode(reference);
 
+		byte[] chatReferenceBytes = null;
+		if (chatReference != null)
+			chatReferenceBytes = Base58.decode(chatReference);
+
 		try (final Repository repository = RepositoryManager.getRepository()) {
 			return repository.getChatRepository().getMessagesMatchingCriteria(
 					before,
 					after,
 					txGroupId,
 					referenceBytes,
+					chatReferenceBytes,
+					hasChatReference,
 					involvingAddresses,
+					sender,
+					encoding,
 					limit, offset, reverse);
 		} catch (DataException e) {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
@@ -121,7 +135,7 @@ public class ChatResource {
 			}
 	)
 	@ApiErrors({ApiError.INVALID_CRITERIA, ApiError.INVALID_ADDRESS, ApiError.REPOSITORY_ISSUE})
-	public ChatMessage getMessageBySignature(@PathParam("signature") String signature58) {
+	public ChatMessage getMessageBySignature(@PathParam("signature") String signature58, @QueryParam("encoding") Encoding encoding) {
 		byte[] signature = Base58.decode(signature58);
 
 		try (final Repository repository = RepositoryManager.getRepository()) {
@@ -131,7 +145,7 @@ public class ChatResource {
 				throw ApiExceptionFactory.INSTANCE.createCustomException(request, ApiError.INVALID_CRITERIA, "Message not found");
 			}
 
-			return repository.getChatRepository().toChatMessage(chatTransactionData);
+			return repository.getChatRepository().toChatMessage(chatTransactionData, encoding);
 		} catch (DataException e) {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
 		}
@@ -154,12 +168,12 @@ public class ChatResource {
 		}
 	)
 	@ApiErrors({ApiError.INVALID_CRITERIA, ApiError.INVALID_ADDRESS, ApiError.REPOSITORY_ISSUE})
-	public ActiveChats getActiveChats(@PathParam("address") String address) {
+	public ActiveChats getActiveChats(@PathParam("address") String address, @QueryParam("encoding") Encoding encoding) {
 		if (address == null || !Crypto.isValidAddress(address))
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_ADDRESS);
 
 		try (final Repository repository = RepositoryManager.getRepository()) {
-			return repository.getChatRepository().getActiveChats(address);
+			return repository.getChatRepository().getActiveChats(address, encoding);
 		} catch (DataException e) {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
 		}

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

@@ -14,6 +14,7 @@ import java.util.List;
 import javax.servlet.http.HttpServletRequest;
 import javax.ws.rs.HeaderParam;
 import javax.ws.rs.POST;
+import javax.ws.rs.GET;
 import javax.ws.rs.Path;
 import javax.ws.rs.core.Context;
 import javax.ws.rs.core.MediaType;
@@ -35,6 +36,37 @@ public class CrossChainBitcoinResource {
 	@Context
 	HttpServletRequest request;
 
+	@GET
+	@Path("/height")
+	@Operation(
+		summary = "Returns current Bitcoin block height",
+		description = "Returns the height of the most recent block in the Bitcoin chain.",
+		responses = {
+			@ApiResponse(
+				content = @Content(
+					schema = @Schema(
+						type = "number"
+					)
+				)
+			)
+		}
+	)
+	@ApiErrors({ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE})
+	public String getBitcoinHeight() {
+		Bitcoin bitcoin = Bitcoin.getInstance();
+
+		try {
+			Integer height = bitcoin.getBlockchainHeight();
+			if (height == null)
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE);
+
+			return height.toString();
+
+		} catch (ForeignBlockchainException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE);
+		}
+	}
+
 	@POST
 	@Path("/walletbalance")
 	@Operation(
@@ -68,7 +100,7 @@ public class CrossChainBitcoinResource {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_PRIVATE_KEY);
 
 		try {
-			Long balance = bitcoin.getWalletBalanceFromTransactions(key58);
+			Long balance = bitcoin.getWalletBalance(key58);
 			if (balance == null)
 				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE);
 
@@ -118,6 +150,45 @@ public class CrossChainBitcoinResource {
 		}
 	}
 
+	@POST
+	@Path("/unusedaddress")
+	@Operation(
+		summary = "Returns first unused address 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 = SimpleTransaction.class ) ) )
+			)
+		}
+	)
+	@ApiErrors({ApiError.INVALID_PRIVATE_KEY, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE})
+	@SecurityRequirement(name = "apiKey")
+	public String getUnusedBitcoinReceiveAddress(@HeaderParam(Security.API_KEY_HEADER) String apiKey, 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.getUnusedReceiveAddress(key58);
+		} catch (ForeignBlockchainException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE);
+		}
+	}
+
 	@POST
 	@Path("/send")
 	@Operation(

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

@@ -14,6 +14,7 @@ import java.util.List;
 import javax.servlet.http.HttpServletRequest;
 import javax.ws.rs.HeaderParam;
 import javax.ws.rs.POST;
+import javax.ws.rs.GET;
 import javax.ws.rs.Path;
 import javax.ws.rs.core.Context;
 import javax.ws.rs.core.MediaType;
@@ -35,6 +36,37 @@ public class CrossChainDigibyteResource {
 	@Context
 	HttpServletRequest request;
 
+	@GET
+	@Path("/height")
+	@Operation(
+		summary = "Returns current Digibyte block height",
+		description = "Returns the height of the most recent block in the Digibyte chain.",
+		responses = {
+			@ApiResponse(
+				content = @Content(
+					schema = @Schema(
+						type = "number"
+					)
+				)
+			)
+		}
+	)
+	@ApiErrors({ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE})
+	public String getDigibyteHeight() {
+		Digibyte digibyte = Digibyte.getInstance();
+
+		try {
+			Integer height = digibyte.getBlockchainHeight();
+			if (height == null)
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE);
+
+			return height.toString();
+
+		} catch (ForeignBlockchainException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE);
+		}
+	}
+
 	@POST
 	@Path("/walletbalance")
 	@Operation(
@@ -68,7 +100,7 @@ public class CrossChainDigibyteResource {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_PRIVATE_KEY);
 
 		try {
-			Long balance = digibyte.getWalletBalanceFromTransactions(key58);
+			Long balance = digibyte.getWalletBalance(key58);
 			if (balance == null)
 				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE);
 
@@ -118,6 +150,45 @@ public class CrossChainDigibyteResource {
 		}
 	}
 
+	@POST
+	@Path("/unusedaddress")
+	@Operation(
+		summary = "Returns first unused address 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 = SimpleTransaction.class ) ) )
+			)
+		}
+	)
+	@ApiErrors({ApiError.INVALID_PRIVATE_KEY, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE})
+	@SecurityRequirement(name = "apiKey")
+	public String getUnusedDigibyteReceiveAddress(@HeaderParam(Security.API_KEY_HEADER) String apiKey, String key58) {
+		Security.checkApiCallAllowed(request);
+
+		Digibyte digibyte = Digibyte.getInstance();
+
+		if (!digibyte.isValidDeterministicKey(key58))
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_PRIVATE_KEY);
+
+		try {
+			return digibyte.getUnusedReceiveAddress(key58);
+		} catch (ForeignBlockchainException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE);
+		}
+	}
+
 	@POST
 	@Path("/send")
 	@Operation(

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

@@ -21,6 +21,7 @@ import org.qortal.crosschain.SimpleTransaction;
 import javax.servlet.http.HttpServletRequest;
 import javax.ws.rs.HeaderParam;
 import javax.ws.rs.POST;
+import javax.ws.rs.GET;
 import javax.ws.rs.Path;
 import javax.ws.rs.core.Context;
 import javax.ws.rs.core.MediaType;
@@ -33,6 +34,37 @@ public class CrossChainDogecoinResource {
 	@Context
 	HttpServletRequest request;
 
+	@GET
+	@Path("/height")
+	@Operation(
+		summary = "Returns current Dogecoin block height",
+		description = "Returns the height of the most recent block in the Dogecoin chain.",
+		responses = {
+			@ApiResponse(
+				content = @Content(
+					schema = @Schema(
+						type = "number"
+					)
+				)
+			)
+		}
+	)
+	@ApiErrors({ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE})
+	public String getDogecoinHeight() {
+		Dogecoin dogecoin = Dogecoin.getInstance();
+
+		try {
+			Integer height = dogecoin.getBlockchainHeight();
+			if (height == null)
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE);
+
+			return height.toString();
+
+		} catch (ForeignBlockchainException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE);
+		}
+	}
+
 	@POST
 	@Path("/walletbalance")
 	@Operation(
@@ -66,7 +98,7 @@ public class CrossChainDogecoinResource {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_PRIVATE_KEY);
 
 		try {
-			Long balance = dogecoin.getWalletBalanceFromTransactions(key58);
+			Long balance = dogecoin.getWalletBalance(key58);
 			if (balance == null)
 				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE);
 
@@ -116,6 +148,45 @@ public class CrossChainDogecoinResource {
 		}
 	}
 
+	@POST
+	@Path("/unusedaddress")
+	@Operation(
+		summary = "Returns first unused address 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 = SimpleTransaction.class ) ) )
+			)
+		}
+	)
+	@ApiErrors({ApiError.INVALID_PRIVATE_KEY, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE})
+	@SecurityRequirement(name = "apiKey")
+	public String getUnusedDogecoinReceiveAddress(@HeaderParam(Security.API_KEY_HEADER) String apiKey, String key58) {
+		Security.checkApiCallAllowed(request);
+
+		Dogecoin dogecoin = Dogecoin.getInstance();
+
+		if (!dogecoin.isValidDeterministicKey(key58))
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_PRIVATE_KEY);
+
+		try {
+			return dogecoin.getUnusedReceiveAddress(key58);
+		} catch (ForeignBlockchainException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE);
+		}
+	}
+
 	@POST
 	@Path("/send")
 	@Operation(

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

@@ -8,11 +8,10 @@ import io.swagger.v3.oas.annotations.responses.ApiResponse;
 import io.swagger.v3.oas.annotations.security.SecurityRequirement;
 import io.swagger.v3.oas.annotations.tags.Tag;
 
-import java.io.IOException;
 import java.math.BigDecimal;
 import java.util.List;
 import java.util.Objects;
-import java.util.concurrent.locks.ReentrantLock;
+import java.util.stream.Collectors;
 
 import javax.servlet.http.HttpServletRequest;
 import javax.ws.rs.*;
@@ -25,7 +24,6 @@ import org.bitcoinj.core.*;
 import org.bitcoinj.script.Script;
 import org.qortal.api.*;
 import org.qortal.api.model.CrossChainBitcoinyHTLCStatus;
-import org.qortal.controller.Controller;
 import org.qortal.crosschain.*;
 import org.qortal.crypto.Crypto;
 import org.qortal.data.at.ATData;
@@ -586,98 +584,103 @@ public class CrossChainHtlcResource {
 			}
 
 			List<TradeBotData> allTradeBotData = repository.getCrossChainRepository().getAllTradeBotData();
-			TradeBotData tradeBotData = allTradeBotData.stream().filter(tradeBotDataItem -> tradeBotDataItem.getAtAddress().equals(atAddress)).findFirst().orElse(null);
-			if (tradeBotData == null)
+			List<TradeBotData> tradeBotDataList = allTradeBotData.stream().filter(tradeBotDataItem -> tradeBotDataItem.getAtAddress().equals(atAddress)).collect(Collectors.toList());
+			if (tradeBotDataList == null || tradeBotDataList.isEmpty())
 				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
 
-			Bitcoiny bitcoiny = (Bitcoiny) acct.getBlockchain();
-			int lockTime = tradeBotData.getLockTimeA();
+			// Loop through all matching entries for this AT address, as there might be more than one
+			for (TradeBotData tradeBotData : tradeBotDataList) {
 
-			// We can't refund P2SH-A until lockTime-A has passed
-			if (NTP.getTime() <= lockTime * 1000L)
-				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_TOO_SOON);
+				if (tradeBotData == null)
+					throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
 
-			// We can't refund P2SH-A until median block time has passed lockTime-A (see BIP113)
-			int medianBlockTime = bitcoiny.getMedianBlockTime();
-			if (medianBlockTime <= lockTime)
-				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_TOO_SOON);
+				Bitcoiny bitcoiny = (Bitcoiny) acct.getBlockchain();
+				int lockTime = tradeBotData.getLockTimeA();
 
-			// Fee for redeem/refund is subtracted from P2SH-A balance.
-			long feeTimestamp = calcFeeTimestamp(lockTime, crossChainTradeData.tradeTimeout);
-			long p2shFee = bitcoiny.getP2shFee(feeTimestamp);
-			long minimumAmountA = crossChainTradeData.expectedForeignAmount + p2shFee;
+				// We can't refund P2SH-A until lockTime-A has passed
+				if (NTP.getTime() <= lockTime * 1000L)
+					continue;
 
-			// Create redeem script based on destination chain
-			byte[] redeemScriptA;
-			String p2shAddressA;
-			BitcoinyHTLC.Status htlcStatusA;
-			if (Objects.equals(bitcoiny.getCurrencyCode(), "ARRR")) {
-				redeemScriptA = PirateChainHTLC.buildScript(tradeBotData.getTradeForeignPublicKey(), lockTime, crossChainTradeData.creatorForeignPKH, tradeBotData.getHashOfSecret());
-				p2shAddressA = PirateChain.getInstance().deriveP2shAddressBPrefix(redeemScriptA);
-				htlcStatusA = PirateChainHTLC.determineHtlcStatus(bitcoiny.getBlockchainProvider(), p2shAddressA, minimumAmountA);
-			}
-			else {
-				redeemScriptA = BitcoinyHTLC.buildScript(tradeBotData.getTradeForeignPublicKeyHash(), lockTime, crossChainTradeData.creatorForeignPKH, tradeBotData.getHashOfSecret());
-				p2shAddressA = bitcoiny.deriveP2shAddress(redeemScriptA);
-				htlcStatusA = BitcoinyHTLC.determineHtlcStatus(bitcoiny.getBlockchainProvider(), p2shAddressA, minimumAmountA);
-			}
-			LOGGER.info(String.format("Refunding P2SH address: %s", p2shAddressA));
+				// We can't refund P2SH-A until median block time has passed lockTime-A (see BIP113)
+				int medianBlockTime = bitcoiny.getMedianBlockTime();
+				if (medianBlockTime <= lockTime)
+					continue;
 
-			switch (htlcStatusA) {
-				case UNFUNDED:
-				case FUNDING_IN_PROGRESS:
-					// Still waiting for P2SH-A to be funded...
-					throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_TOO_SOON);
+				// Fee for redeem/refund is subtracted from P2SH-A balance.
+				long feeTimestamp = calcFeeTimestamp(lockTime, crossChainTradeData.tradeTimeout);
+				long p2shFee = bitcoiny.getP2shFee(feeTimestamp);
+				long minimumAmountA = crossChainTradeData.expectedForeignAmount + p2shFee;
 
-				case REDEEM_IN_PROGRESS:
-				case REDEEMED:
-				case REFUND_IN_PROGRESS:
-				case REFUNDED:
-					// Too late!
-					return false;
+				// Create redeem script based on destination chain
+				byte[] redeemScriptA;
+				String p2shAddressA;
+				BitcoinyHTLC.Status htlcStatusA;
+				if (Objects.equals(bitcoiny.getCurrencyCode(), "ARRR")) {
+					redeemScriptA = PirateChainHTLC.buildScript(tradeBotData.getTradeForeignPublicKey(), lockTime, crossChainTradeData.creatorForeignPKH, tradeBotData.getHashOfSecret());
+					p2shAddressA = PirateChain.getInstance().deriveP2shAddressBPrefix(redeemScriptA);
+					htlcStatusA = PirateChainHTLC.determineHtlcStatus(bitcoiny.getBlockchainProvider(), p2shAddressA, minimumAmountA);
+				} else {
+					redeemScriptA = BitcoinyHTLC.buildScript(tradeBotData.getTradeForeignPublicKeyHash(), lockTime, crossChainTradeData.creatorForeignPKH, tradeBotData.getHashOfSecret());
+					p2shAddressA = bitcoiny.deriveP2shAddress(redeemScriptA);
+					htlcStatusA = BitcoinyHTLC.determineHtlcStatus(bitcoiny.getBlockchainProvider(), p2shAddressA, minimumAmountA);
+				}
+				LOGGER.info(String.format("Refunding P2SH address: %s", p2shAddressA));
 
-				case FUNDED:{
-					Coin refundAmount = Coin.valueOf(crossChainTradeData.expectedForeignAmount);
+				switch (htlcStatusA) {
+					case UNFUNDED:
+					case FUNDING_IN_PROGRESS:
+						// Still waiting for P2SH-A to be funded...
+						continue;
 
-					if (Objects.equals(bitcoiny.getCurrencyCode(), "ARRR")) {
-						// Pirate Chain custom integration
+					case REDEEM_IN_PROGRESS:
+					case REDEEMED:
+					case REFUND_IN_PROGRESS:
+					case REFUNDED:
+						// Too late!
+						continue;
 
-						PirateChain pirateChain = PirateChain.getInstance();
-						String p2shAddressT3 = pirateChain.deriveP2shAddress(redeemScriptA);
+					case FUNDED: {
+						Coin refundAmount = Coin.valueOf(crossChainTradeData.expectedForeignAmount);
 
-						// Get funding txid
-						String fundingTxidHex = PirateChainHTLC.getUnspentFundingTxid(pirateChain.getBlockchainProvider(), p2shAddressA, minimumAmountA);
-						if (fundingTxidHex == null) {
-							throw new ForeignBlockchainException("Missing funding txid when refunding P2SH");
+						if (Objects.equals(bitcoiny.getCurrencyCode(), "ARRR")) {
+							// Pirate Chain custom integration
+
+							PirateChain pirateChain = PirateChain.getInstance();
+							String p2shAddressT3 = pirateChain.deriveP2shAddress(redeemScriptA);
+
+							// Get funding txid
+							String fundingTxidHex = PirateChainHTLC.getUnspentFundingTxid(pirateChain.getBlockchainProvider(), p2shAddressA, minimumAmountA);
+							if (fundingTxidHex == null) {
+								throw new ForeignBlockchainException("Missing funding txid when refunding P2SH");
+							}
+							String fundingTxid58 = Base58.encode(HashCode.fromString(fundingTxidHex).asBytes());
+
+							byte[] privateKey = tradeBotData.getTradePrivateKey();
+							String privateKey58 = Base58.encode(privateKey);
+							String redeemScript58 = Base58.encode(redeemScriptA);
+
+							String txid = PirateChain.getInstance().refundP2sh(p2shAddressT3,
+									receiveAddress, refundAmount.value, redeemScript58, fundingTxid58, lockTime, privateKey58);
+							LOGGER.info("Refund txid: {}", txid);
+						} else {
+							// ElectrumX coins
+
+							ECKey refundKey = ECKey.fromPrivate(tradeBotData.getTradePrivateKey());
+							List<TransactionOutput> fundingOutputs = bitcoiny.getUnspentOutputs(p2shAddressA);
+
+							// Validate the destination foreign blockchain address
+							Address receiving = Address.fromString(bitcoiny.getNetworkParameters(), receiveAddress);
+							if (receiving.getOutputScriptType() != Script.ScriptType.P2PKH)
+								throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+
+							Transaction p2shRefundTransaction = BitcoinyHTLC.buildRefundTransaction(bitcoiny.getNetworkParameters(), refundAmount, refundKey,
+									fundingOutputs, redeemScriptA, lockTime, receiving.getHash());
+
+							bitcoiny.broadcastTransaction(p2shRefundTransaction);
 						}
-						String fundingTxid58 = Base58.encode(HashCode.fromString(fundingTxidHex).asBytes());
 
-						byte[] privateKey = tradeBotData.getTradePrivateKey();
-						String privateKey58 = Base58.encode(privateKey);
-						String redeemScript58 = Base58.encode(redeemScriptA);
-
-						String txid = PirateChain.getInstance().refundP2sh(p2shAddressT3,
-								receiveAddress, refundAmount.value, redeemScript58, fundingTxid58, lockTime, privateKey58);
-						LOGGER.info("Refund txid: {}", txid);
+						return true;
 					}
-					else {
-						// ElectrumX coins
-
-						ECKey refundKey = ECKey.fromPrivate(tradeBotData.getTradePrivateKey());
-						List<TransactionOutput> fundingOutputs = bitcoiny.getUnspentOutputs(p2shAddressA);
-
-						// Validate the destination foreign blockchain address
-						Address receiving = Address.fromString(bitcoiny.getNetworkParameters(), receiveAddress);
-						if (receiving.getOutputScriptType() != Script.ScriptType.P2PKH)
-							throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
-
-						Transaction p2shRefundTransaction = BitcoinyHTLC.buildRefundTransaction(bitcoiny.getNetworkParameters(), refundAmount, refundKey,
-								fundingOutputs, redeemScriptA, lockTime, receiving.getHash());
-
-						bitcoiny.broadcastTransaction(p2shRefundTransaction);
-					}
-
-					return true;
 				}
 			}
 

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

@@ -14,6 +14,7 @@ import java.util.List;
 import javax.servlet.http.HttpServletRequest;
 import javax.ws.rs.HeaderParam;
 import javax.ws.rs.POST;
+import javax.ws.rs.GET;
 import javax.ws.rs.Path;
 import javax.ws.rs.core.Context;
 import javax.ws.rs.core.MediaType;
@@ -35,6 +36,37 @@ public class CrossChainLitecoinResource {
 	@Context
 	HttpServletRequest request;
 
+	@GET
+	@Path("/height")
+	@Operation(
+		summary = "Returns current Litecoin block height",
+		description = "Returns the height of the most recent block in the Litecoin chain.",
+		responses = {
+			@ApiResponse(
+				content = @Content(
+					schema = @Schema(
+						type = "number"
+					)
+				)
+			)
+		}
+	)
+	@ApiErrors({ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE})
+	public String getLitecoinHeight() {
+		Litecoin litecoin = Litecoin.getInstance();
+
+		try {
+			Integer height = litecoin.getBlockchainHeight();
+			if (height == null)
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE);
+
+			return height.toString();
+
+		} catch (ForeignBlockchainException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE);
+		}
+	}
+
 	@POST
 	@Path("/walletbalance")
 	@Operation(
@@ -68,7 +100,7 @@ public class CrossChainLitecoinResource {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_PRIVATE_KEY);
 
 		try {
-			Long balance = litecoin.getWalletBalanceFromTransactions(key58);
+			Long balance = litecoin.getWalletBalance(key58);
 			if (balance == null)
 				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE);
 
@@ -118,6 +150,45 @@ public class CrossChainLitecoinResource {
 		}
 	}
 
+	@POST
+	@Path("/unusedaddress")
+	@Operation(
+		summary = "Returns first unused address 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 = SimpleTransaction.class ) ) )
+			)
+		}
+	)
+	@ApiErrors({ApiError.INVALID_PRIVATE_KEY, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE})
+	@SecurityRequirement(name = "apiKey")
+	public String getUnusedLitecoinReceiveAddress(@HeaderParam(Security.API_KEY_HEADER) String apiKey, 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.getUnusedReceiveAddress(key58);
+		} catch (ForeignBlockchainException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE);
+		}
+	}
+
 	@POST
 	@Path("/send")
 	@Operation(

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

@@ -20,6 +20,7 @@ import org.qortal.crosschain.SimpleTransaction;
 import javax.servlet.http.HttpServletRequest;
 import javax.ws.rs.HeaderParam;
 import javax.ws.rs.POST;
+import javax.ws.rs.GET;
 import javax.ws.rs.Path;
 import javax.ws.rs.core.Context;
 import javax.ws.rs.core.MediaType;
@@ -32,6 +33,37 @@ public class CrossChainPirateChainResource {
 	@Context
 	HttpServletRequest request;
 
+	@GET
+	@Path("/height")
+	@Operation(
+		summary = "Returns current PirateChain block height",
+		description = "Returns the height of the most recent block in the PirateChain chain.",
+		responses = {
+			@ApiResponse(
+				content = @Content(
+					schema = @Schema(
+						type = "number"
+					)
+				)
+			)
+		}
+	)
+	@ApiErrors({ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE})
+	public String getPirateChainHeight() {
+		PirateChain pirateChain = PirateChain.getInstance();
+
+		try {
+			Integer height = pirateChain.getBlockchainHeight();
+			if (height == null)
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE);
+
+			return height.toString();
+
+		} catch (ForeignBlockchainException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE);
+		}
+	}
+
 	@POST
 	@Path("/walletbalance")
 	@Operation(

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

@@ -14,6 +14,7 @@ import java.util.List;
 import javax.servlet.http.HttpServletRequest;
 import javax.ws.rs.HeaderParam;
 import javax.ws.rs.POST;
+import javax.ws.rs.GET;
 import javax.ws.rs.Path;
 import javax.ws.rs.core.Context;
 import javax.ws.rs.core.MediaType;
@@ -35,6 +36,37 @@ public class CrossChainRavencoinResource {
 	@Context
 	HttpServletRequest request;
 
+	@GET
+	@Path("/height")
+	@Operation(
+		summary = "Returns current Ravencoin block height",
+		description = "Returns the height of the most recent block in the Ravencoin chain.",
+		responses = {
+			@ApiResponse(
+				content = @Content(
+					schema = @Schema(
+						type = "number"
+					)
+				)
+			)
+		}
+	)
+	@ApiErrors({ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE})
+	public String getRavencoinHeight() {
+		Ravencoin ravencoin = Ravencoin.getInstance();
+
+		try {
+			Integer height = ravencoin.getBlockchainHeight();
+			if (height == null)
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE);
+
+			return height.toString();
+
+		} catch (ForeignBlockchainException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE);
+		}
+	}
+
 	@POST
 	@Path("/walletbalance")
 	@Operation(
@@ -68,7 +100,7 @@ public class CrossChainRavencoinResource {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_PRIVATE_KEY);
 
 		try {
-			Long balance = ravencoin.getWalletBalanceFromTransactions(key58);
+			Long balance = ravencoin.getWalletBalance(key58);
 			if (balance == null)
 				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE);
 
@@ -118,6 +150,45 @@ public class CrossChainRavencoinResource {
 		}
 	}
 
+	@POST
+	@Path("/unusedaddress")
+	@Operation(
+		summary = "Returns first unused address 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 = SimpleTransaction.class ) ) )
+			)
+		}
+	)
+	@ApiErrors({ApiError.INVALID_PRIVATE_KEY, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE})
+	@SecurityRequirement(name = "apiKey")
+	public String getUnusedRavencoinReceiveAddress(@HeaderParam(Security.API_KEY_HEADER) String apiKey, String key58) {
+		Security.checkApiCallAllowed(request);
+
+		Ravencoin ravencoin = Ravencoin.getInstance();
+
+		if (!ravencoin.isValidDeterministicKey(key58))
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_PRIVATE_KEY);
+
+		try {
+			return ravencoin.getUnusedReceiveAddress(key58);
+		} catch (ForeignBlockchainException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_NETWORK_ISSUE);
+		}
+	}
+
 	@POST
 	@Path("/send")
 	@Operation(

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

@@ -11,6 +11,7 @@ import io.swagger.v3.oas.annotations.security.SecurityRequirement;
 import io.swagger.v3.oas.annotations.tags.Tag;
 
 import java.util.List;
+import java.util.Objects;
 import java.util.stream.Collectors;
 
 import javax.servlet.http.HttpServletRequest;
@@ -38,9 +39,12 @@ 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.MessageTransactionData;
+import org.qortal.data.transaction.TransactionData;
 import org.qortal.repository.DataException;
 import org.qortal.repository.Repository;
 import org.qortal.repository.RepositoryManager;
+import org.qortal.transaction.Transaction;
 import org.qortal.utils.Base58;
 import org.qortal.utils.NTP;
 
@@ -223,6 +227,17 @@ public class CrossChainTradeBotResource {
 			if (crossChainTradeData.mode != AcctMode.OFFERING)
 				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
 
+			// Check if there is a buy or a cancel request in progress for this trade
+			List<Transaction.TransactionType> txTypes = List.of(Transaction.TransactionType.MESSAGE);
+			List<TransactionData> unconfirmed = repository.getTransactionRepository().getUnconfirmedTransactions(txTypes, null, 0, 0, false);
+			for (TransactionData  transactionData : unconfirmed) {
+				MessageTransactionData messageTransactionData = (MessageTransactionData) transactionData;
+				if (Objects.equals(messageTransactionData.getRecipient(), atAddress)) {
+					// There is a pending request for this trade, so block this buy attempt to reduce the risk of refunds
+					throw ApiExceptionFactory.INSTANCE.createCustomException(request, ApiError.INVALID_CRITERIA, "Trade has an existing buy request or is pending cancellation.");
+				}
+			}
+
 			AcctTradeBot.ResponseResult result = TradeBot.getInstance().startResponse(repository, atData, acct, crossChainTradeData,
 					tradeBotRespondRequest.foreignKey, tradeBotRespondRequest.receivingAddress);
 

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

@@ -0,0 +1,197 @@
+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 org.qortal.api.ApiError;
+import org.qortal.api.ApiErrors;
+import org.qortal.api.ApiExceptionFactory;
+import org.qortal.data.transaction.CreatePollTransactionData;
+import org.qortal.data.transaction.PaymentTransactionData;
+import org.qortal.data.transaction.VoteOnPollTransactionData;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.repository.RepositoryManager;
+import org.qortal.settings.Settings;
+import org.qortal.transaction.Transaction;
+import org.qortal.transform.TransformationException;
+import org.qortal.transform.transaction.CreatePollTransactionTransformer;
+import org.qortal.transform.transaction.PaymentTransactionTransformer;
+import org.qortal.transform.transaction.VoteOnPollTransactionTransformer;
+import org.qortal.utils.Base58;
+
+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 io.swagger.v3.oas.annotations.Parameter;
+import io.swagger.v3.oas.annotations.media.ArraySchema;
+import java.util.List;
+import javax.ws.rs.GET;
+import javax.ws.rs.PathParam;
+import javax.ws.rs.QueryParam;
+import org.qortal.api.ApiException;
+import org.qortal.data.voting.PollData;
+
+@Path("/polls")
+@Tag(name = "Polls")
+public class PollsResource {
+    @Context
+    HttpServletRequest request;
+
+    @GET
+    @Operation(
+            summary = "List all polls",
+            responses = {
+                    @ApiResponse(
+                            description = "poll info",
+                            content = @Content(
+                                    mediaType = MediaType.APPLICATION_JSON,
+                                    array = @ArraySchema(schema = @Schema(implementation = PollData.class))
+                            )
+                    )
+            }
+    )
+    @ApiErrors({ApiError.REPOSITORY_ISSUE})
+    public List<PollData> getAllPolls(@Parameter(
+            ref = "limit"
+    ) @QueryParam("limit") Integer limit, @Parameter(
+            ref = "offset"
+    ) @QueryParam("offset") Integer offset, @Parameter(
+            ref = "reverse"
+    ) @QueryParam("reverse") Boolean reverse) {
+            try (final Repository repository = RepositoryManager.getRepository()) {
+		    List<PollData> allPollData = repository.getVotingRepository().getAllPolls(limit, offset, reverse);
+		    return allPollData;
+            } catch (DataException e) {
+		    throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
+            }
+    }
+
+    @GET
+    @Path("/{pollName}")
+    @Operation(
+            summary = "Info on poll",
+            responses = {
+                    @ApiResponse(
+                            description = "poll info",
+                            content = @Content(
+                                    mediaType = MediaType.APPLICATION_JSON,
+                                    schema = @Schema(implementation = PollData.class)
+                            )
+                    )
+            }
+    )
+    @ApiErrors({ApiError.REPOSITORY_ISSUE})
+    public PollData getPollData(@PathParam("pollName") String pollName) {
+            try (final Repository repository = RepositoryManager.getRepository()) {
+                    PollData pollData = repository.getVotingRepository().fromPollName(pollName);
+                    if (pollData == null)
+                            throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.POLL_NO_EXISTS);
+
+                    return pollData;
+            } catch (ApiException e) {
+                    throw e;
+            } catch (DataException e) {
+                    throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
+            }
+    }
+
+    @POST
+    @Path("/create")
+    @Operation(
+            summary = "Build raw, unsigned, CREATE_POLL transaction",
+            requestBody = @RequestBody(
+                    required = true,
+                    content = @Content(
+                            mediaType = MediaType.APPLICATION_JSON,
+                            schema = @Schema(
+                                    implementation = CreatePollTransactionData.class
+                            )
+                    )
+            ),
+            responses = {
+                    @ApiResponse(
+                            description = "raw, unsigned, CREATE_POLL transaction encoded in Base58",
+                            content = @Content(
+                                    mediaType = MediaType.TEXT_PLAIN,
+                                    schema = @Schema(
+                                            type = "string"
+                                    )
+                            )
+                    )
+            }
+    )
+    @ApiErrors({ApiError.NON_PRODUCTION, ApiError.TRANSACTION_INVALID, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
+    public String CreatePoll(CreatePollTransactionData transactionData) {
+        if (Settings.getInstance().isApiRestricted())
+            throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.NON_PRODUCTION);
+
+        try (final Repository repository = RepositoryManager.getRepository()) {
+            Transaction transaction = Transaction.fromData(repository, transactionData);
+
+            Transaction.ValidationResult result = transaction.isValidUnconfirmed();
+            if (result != Transaction.ValidationResult.OK)
+                throw TransactionsResource.createTransactionInvalidException(request, result);
+
+            byte[] bytes = CreatePollTransactionTransformer.toBytes(transactionData);
+            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("/vote")
+    @Operation(
+            summary = "Build raw, unsigned, VOTE_ON_POLL transaction",
+            requestBody = @RequestBody(
+                    required = true,
+                    content = @Content(
+                            mediaType = MediaType.APPLICATION_JSON,
+                            schema = @Schema(
+                                    implementation = VoteOnPollTransactionData.class
+                            )
+                    )
+            ),
+            responses = {
+                    @ApiResponse(
+                            description = "raw, unsigned, VOTE_ON_POLL transaction encoded in Base58",
+                            content = @Content(
+                                    mediaType = MediaType.TEXT_PLAIN,
+                                    schema = @Schema(
+                                            type = "string"
+                                    )
+                            )
+                    )
+            }
+    )
+    @ApiErrors({ApiError.NON_PRODUCTION, ApiError.TRANSACTION_INVALID, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
+    public String VoteOnPoll(VoteOnPollTransactionData transactionData) {
+        if (Settings.getInstance().isApiRestricted())
+            throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.NON_PRODUCTION);
+
+        try (final Repository repository = RepositoryManager.getRepository()) {
+            Transaction transaction = Transaction.fromData(repository, transactionData);
+
+            Transaction.ValidationResult result = transaction.isValidUnconfirmed();
+            if (result != Transaction.ValidationResult.OK)
+                throw TransactionsResource.createTransactionInvalidException(request, result);
+
+            byte[] bytes = VoteOnPollTransactionTransformer.toBytes(transactionData);
+            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);
+        }
+    }
+    
+}

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

@@ -9,6 +9,8 @@ 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.io.IOException;
+import java.io.StringWriter;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.InvocationTargetException;
 import java.util.ArrayList;
@@ -18,19 +20,12 @@ import java.util.concurrent.TimeUnit;
 import java.util.concurrent.locks.ReentrantLock;
 
 import javax.servlet.http.HttpServletRequest;
-import javax.ws.rs.GET;
-import javax.ws.rs.POST;
-import javax.ws.rs.Path;
-import javax.ws.rs.PathParam;
-import javax.ws.rs.QueryParam;
+import javax.ws.rs.*;
 import javax.ws.rs.core.Context;
 import javax.ws.rs.core.MediaType;
 
 import org.qortal.account.PrivateKeyAccount;
-import org.qortal.api.ApiError;
-import org.qortal.api.ApiErrors;
-import org.qortal.api.ApiException;
-import org.qortal.api.ApiExceptionFactory;
+import org.qortal.api.*;
 import org.qortal.api.model.SimpleTransactionSignRequest;
 import org.qortal.controller.Controller;
 import org.qortal.controller.LiteNode;
@@ -709,7 +704,7 @@ public class TransactionsResource {
 		),
 		responses = {
 			@ApiResponse(
-				description = "true if accepted, false otherwise",
+				description = "For API version 1, this returns true if accepted.\nFor API version 2, the transactionData is returned as a JSON string if accepted.",
 				content = @Content(
 					mediaType = MediaType.TEXT_PLAIN,
 					schema = @Schema(
@@ -722,7 +717,9 @@ public class TransactionsResource {
 	@ApiErrors({
 		ApiError.BLOCKCHAIN_NEEDS_SYNC, ApiError.INVALID_SIGNATURE, ApiError.INVALID_DATA, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE
 	})
-	public String processTransaction(String rawBytes58) {
+	public String processTransaction(String rawBytes58, @HeaderParam(ApiService.API_VERSION_HEADER) String apiVersionHeader) {
+		int apiVersion = ApiService.getApiVersion(request);
+
 		// Only allow a transaction to be processed if our latest block is less than 60 minutes old
 		// If older than this, we should first wait until the blockchain is synced
 		final Long minLatestBlockTimestamp = NTP.getTime() - (60 * 60 * 1000L);
@@ -759,13 +756,27 @@ public class TransactionsResource {
 				blockchainLock.unlock();
 			}
 
-			return "true";
+			switch (apiVersion) {
+				case 1:
+					return "true";
+
+				case 2:
+				default:
+					// Marshall transactionData to string
+					StringWriter stringWriter = new StringWriter();
+					ApiRequest.marshall(stringWriter, transactionData);
+					return stringWriter.toString();
+			}
+
+
 		} catch (NumberFormatException e) {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_DATA, e);
 		} catch (DataException e) {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
 		} catch (InterruptedException e) {
 			throw createTransactionInvalidException(request, ValidationResult.NO_BLOCKCHAIN_LOCK);
+		} catch (IOException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.TRANSFORMATION_ERROR, e);
 		}
 	}
 

src/main/java/org/qortal/api/restricted/resource/AdminResource.java

@@ -1,4 +1,4 @@
-package org.qortal.api.resource;
+package org.qortal.api.restricted.resource;
 
 import io.swagger.v3.oas.annotations.Operation;
 import io.swagger.v3.oas.annotations.Parameter;
@@ -20,6 +20,7 @@ import java.time.LocalDate;
 import java.time.LocalTime;
 import java.time.OffsetDateTime;
 import java.time.ZoneOffset;
+import java.util.Arrays;
 import java.util.List;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;
@@ -31,10 +32,13 @@ import javax.ws.rs.*;
 import javax.ws.rs.core.Context;
 import javax.ws.rs.core.MediaType;
 
+import org.apache.commons.lang3.reflect.FieldUtils;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.apache.logging.log4j.core.LoggerContext;
 import org.apache.logging.log4j.core.appender.RollingFileAppender;
+import org.json.JSONArray;
+import org.json.JSONObject;
 import org.qortal.account.Account;
 import org.qortal.account.PrivateKeyAccount;
 import org.qortal.api.*;
@@ -42,9 +46,11 @@ import org.qortal.api.model.ActivitySummary;
 import org.qortal.api.model.NodeInfo;
 import org.qortal.api.model.NodeStatus;
 import org.qortal.block.BlockChain;
+import org.qortal.controller.AutoUpdate;
 import org.qortal.controller.Controller;
 import org.qortal.controller.Synchronizer;
 import org.qortal.controller.Synchronizer.SynchronizationResult;
+import org.qortal.controller.repository.BlockArchiveRebuilder;
 import org.qortal.data.account.MintingAccountData;
 import org.qortal.data.account.RewardShareData;
 import org.qortal.network.Network;
@@ -152,6 +158,53 @@ public class AdminResource {
 		return nodeStatus;
 	}
 
+	@GET
+	@Path("/settings")
+	@Operation(
+		summary = "Fetch node settings",
+		responses = {
+			@ApiResponse(
+				content = @Content(mediaType = MediaType.APPLICATION_JSON, schema = @Schema(implementation = Settings.class))
+			)
+		}
+	)
+	public Settings settings() {
+		Settings nodeSettings = Settings.getInstance();
+
+		return nodeSettings;
+	}
+
+	@GET
+	@Path("/settings/{setting}")
+	@Operation(
+			summary = "Fetch a single node setting",
+			responses = {
+					@ApiResponse(
+							content = @Content(mediaType = MediaType.TEXT_PLAIN, schema = @Schema(type = "string"))
+					)
+			}
+	)
+	public Object setting(@PathParam("setting") String setting) {
+		try {
+			Object settingValue = FieldUtils.readField(Settings.getInstance(), setting, true);
+			if (settingValue == null) {
+				return "null";
+			}
+			else if (settingValue instanceof String[]) {
+				JSONArray array = new JSONArray(settingValue);
+				return array.toString(4);
+			}
+			else if (settingValue instanceof List) {
+				JSONArray array = new JSONArray((List<Object>) settingValue);
+				return array.toString(4);
+			}
+			return settingValue;
+
+		} catch (IllegalAccessException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA, e);
+		}
+	}
+
 	@GET
 	@Path("/stop")
 	@Operation(
@@ -182,6 +235,37 @@ public class AdminResource {
 		return "true";
 	}
 
+	@GET
+	@Path("/restart")
+	@Operation(
+		summary = "Restart",
+		description = "Restart",
+		responses = {
+			@ApiResponse(
+				description = "\"true\"",
+				content = @Content(mediaType = MediaType.TEXT_PLAIN, schema = @Schema(type = "string"))
+			)
+		}
+	)
+	@SecurityRequirement(name = "apiKey")
+	public String restart(@HeaderParam(Security.API_KEY_HEADER) String apiKey) {
+		Security.checkApiCallAllowed(request);
+
+		new Thread(() -> {
+			// Short sleep to allow HTTP response body to be emitted
+			try {
+				Thread.sleep(1000);
+			} catch (InterruptedException e) {
+				// Not important
+			}
+
+			AutoUpdate.attemptRestart();
+
+		}).start();
+
+		return "true";
+	}
+
 	@GET
 	@Path("/summary")
 	@Operation(
@@ -222,6 +306,42 @@ public class AdminResource {
 		}
 	}
 
+	@GET
+	@Path("/summary/alltime")
+	@Operation(
+			summary = "Summary of activity since genesis",
+			responses = {
+					@ApiResponse(
+							content = @Content(schema = @Schema(implementation = ActivitySummary.class))
+					)
+			}
+	)
+	@ApiErrors({ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
+	public ActivitySummary allTimeSummary(@HeaderParam(Security.API_KEY_HEADER) String apiKey) {
+		Security.checkApiCallAllowed(request);
+
+		ActivitySummary summary = new ActivitySummary();
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			int startHeight = 1;
+			long start = repository.getBlockRepository().fromHeight(startHeight).getTimestamp();
+			int endHeight = repository.getBlockRepository().getBlockchainHeight();
+
+			summary.setBlockCount(endHeight - startHeight);
+
+			summary.setTransactionCountByType(repository.getTransactionRepository().getTransactionSummary(startHeight + 1, endHeight));
+
+			summary.setAssetsIssued(repository.getAssetRepository().getRecentAssetIds(start).size());
+
+			summary.setNamesRegistered (repository.getNameRepository().getRecentNames(start).size());
+
+			return summary;
+		} catch (DataException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
+		}
+	}
+
 	@GET
 	@Path("/enginestats")
 	@Operation(
@@ -698,6 +818,64 @@ public class AdminResource {
 		}
 	}
 
+	@POST
+	@Path("/repository/archive/rebuild")
+	@Operation(
+			summary = "Rebuild archive",
+			description = "Rebuilds archive files, using the specified serialization version",
+			requestBody = @RequestBody(
+					required = true,
+					content = @Content(
+							mediaType = MediaType.TEXT_PLAIN,
+							schema = @Schema(
+									type = "number", example = "2"
+							)
+					)
+			),
+			responses = {
+					@ApiResponse(
+							description = "\"true\"",
+							content = @Content(mediaType = MediaType.TEXT_PLAIN, schema = @Schema(type = "string"))
+					)
+			}
+	)
+	@ApiErrors({ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
+	public String rebuildArchive(@HeaderParam(Security.API_KEY_HEADER) String apiKey, Integer serializationVersion) {
+		Security.checkApiCallAllowed(request);
+
+		// Default serialization version to value specified in settings
+		if (serializationVersion == null) {
+			serializationVersion = Settings.getInstance().getDefaultArchiveVersion();
+		}
+
+		try {
+			// We don't actually need to lock the blockchain here, but we'll do it anyway so that
+			// the node can focus on rebuilding rather than synchronizing / minting.
+			ReentrantLock blockchainLock = Controller.getInstance().getBlockchainLock();
+
+			blockchainLock.lockInterruptibly();
+
+			try {
+				BlockArchiveRebuilder blockArchiveRebuilder = new BlockArchiveRebuilder(serializationVersion);
+				blockArchiveRebuilder.start();
+
+				return "true";
+
+			} catch (IOException e) {
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA, e);
+
+			} finally {
+				blockchainLock.unlock();
+			}
+		} catch (InterruptedException e) {
+			// We couldn't lock blockchain to perform rebuild
+			return "false";
+		} catch (DataException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
+		}
+	}
+
 	@DELETE
 	@Path("/repository")
 	@Operation(

src/main/java/org/qortal/api/restricted/resource/BootstrapResource.java

@@ -1,4 +1,4 @@
-package org.qortal.api.resource;
+package org.qortal.api.restricted.resource;
 
 import io.swagger.v3.oas.annotations.Operation;
 import io.swagger.v3.oas.annotations.media.Content;
@@ -60,7 +60,7 @@ public class BootstrapResource {
 			bootstrap.validateBlockchain();
 			return bootstrap.create();
 
-		} catch (DataException | InterruptedException | IOException e) {
+		} catch (Exception e) {
 			LOGGER.info("Unable to create bootstrap", e);
 			throw ApiExceptionFactory.INSTANCE.createCustomException(request, ApiError.REPOSITORY_ISSUE, e.getMessage());
 		}

src/main/java/org/qortal/api/restricted/resource/RenderResource.java

@@ -1,4 +1,4 @@
-package org.qortal.api.resource;
+package org.qortal.api.restricted.resource;
 
 import javax.servlet.ServletContext;
 import javax.servlet.http.HttpServletRequest;
@@ -8,7 +8,6 @@ import javax.ws.rs.core.Context;
 import javax.ws.rs.core.MediaType;
 import java.io.*;
 import java.nio.file.Paths;
-import java.util.Map;
 
 import io.swagger.v3.oas.annotations.Operation;
 import io.swagger.v3.oas.annotations.media.Content;
@@ -28,8 +27,8 @@ import org.qortal.arbitrary.exception.MissingDataException;
 import org.qortal.controller.arbitrary.ArbitraryDataRenderManager;
 import org.qortal.data.transaction.ArbitraryTransactionData.*;
 import org.qortal.repository.DataException;
-import org.qortal.settings.Settings;
 import org.qortal.arbitrary.ArbitraryDataFile.*;
+import org.qortal.settings.Settings;
 import org.qortal.utils.Base58;
 
 
@@ -43,60 +42,6 @@ public class RenderResource {
     @Context HttpServletResponse response;
     @Context ServletContext context;
 
-    @POST
-    @Path("/preview")
-    @Operation(
-            summary = "Generate preview URL based on a user-supplied path and service",
-            requestBody = @RequestBody(
-                    required = true,
-                    content = @Content(
-                            mediaType = MediaType.TEXT_PLAIN,
-                            schema = @Schema(
-                                    type = "string", example = "/Users/user/Documents/MyStaticWebsite"
-                            )
-                    )
-            ),
-            responses = {
-                    @ApiResponse(
-                            description = "a temporary URL to preview the website",
-                            content = @Content(
-                                    mediaType = MediaType.TEXT_PLAIN,
-                                    schema = @Schema(
-                                            type = "string"
-                                    )
-                            )
-                    )
-            }
-    )
-    @SecurityRequirement(name = "apiKey")
-    public String preview(@HeaderParam(Security.API_KEY_HEADER) String apiKey, String directoryPath) {
-        Security.checkApiCallAllowed(request);
-        Method method = Method.PUT;
-        Compression compression = Compression.ZIP;
-
-        ArbitraryDataWriter arbitraryDataWriter = new ArbitraryDataWriter(Paths.get(directoryPath),
-                null, Service.WEBSITE, null, method, compression,
-                null, null, null, null);
-        try {
-            arbitraryDataWriter.save();
-        } catch (IOException | DataException | InterruptedException | MissingDataException e) {
-            LOGGER.info("Unable to create arbitrary data file: {}", e.getMessage());
-            throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE);
-        } catch (RuntimeException e) {
-            LOGGER.info("Unable to create arbitrary data file: {}", e.getMessage());
-            throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_DATA);
-        }
-
-        ArbitraryDataFile arbitraryDataFile = arbitraryDataWriter.getArbitraryDataFile();
-        if (arbitraryDataFile != null) {
-            String digest58 = arbitraryDataFile.digest58();
-            if (digest58 != null) {
-                return "http://localhost:12393/render/hash/" + digest58 + "?secret=" + Base58.encode(arbitraryDataFile.getSecret());
-            }
-        }
-        return "Unable to generate preview URL";
-    }
-
     @POST
     @Path("/authorize/{resourceId}")
     @SecurityRequirement(name = "apiKey")
@@ -140,8 +85,10 @@ public class RenderResource {
     @SecurityRequirement(name = "apiKey")
     public HttpServletResponse getIndexBySignature(@PathParam("signature") String signature,
                                                    @QueryParam("theme") String theme) {
-        Security.requirePriorAuthorization(request, signature, Service.WEBSITE, null);
-        return this.get(signature, ResourceIdType.SIGNATURE, null, "/", null, "/render/signature", true, true, theme);
+        if (!Settings.getInstance().isQDNAuthBypassEnabled())
+            Security.requirePriorAuthorization(request, signature, Service.WEBSITE, null);
+
+        return this.get(signature, ResourceIdType.SIGNATURE, null, null, "/", null, "/render/signature", true, true, theme);
     }
 
     @GET
@@ -149,8 +96,10 @@ public class RenderResource {
     @SecurityRequirement(name = "apiKey")
     public HttpServletResponse getPathBySignature(@PathParam("signature") String signature, @PathParam("path") String inPath,
                                                   @QueryParam("theme") String theme) {
-        Security.requirePriorAuthorization(request, signature, Service.WEBSITE, null);
-        return this.get(signature, ResourceIdType.SIGNATURE, null, inPath,null, "/render/signature", true, true, theme);
+        if (!Settings.getInstance().isQDNAuthBypassEnabled())
+            Security.requirePriorAuthorization(request, signature, Service.WEBSITE, null);
+
+        return this.get(signature, ResourceIdType.SIGNATURE, null, null, inPath,null, "/render/signature", true, true, theme);
     }
 
     @GET
@@ -158,8 +107,10 @@ public class RenderResource {
     @SecurityRequirement(name = "apiKey")
     public HttpServletResponse getIndexByHash(@PathParam("hash") String hash58, @QueryParam("secret") String secret58,
                                               @QueryParam("theme") String theme) {
-        Security.requirePriorAuthorization(request, hash58, Service.WEBSITE, null);
-        return this.get(hash58, ResourceIdType.FILE_HASH, Service.WEBSITE, "/", secret58, "/render/hash", true, false, theme);
+        if (!Settings.getInstance().isQDNAuthBypassEnabled())
+            Security.requirePriorAuthorization(request, hash58, Service.WEBSITE, null);
+
+        return this.get(hash58, ResourceIdType.FILE_HASH, Service.ARBITRARY_DATA, null, "/", secret58, "/render/hash", true, false, theme);
     }
 
     @GET
@@ -168,8 +119,10 @@ public class RenderResource {
     public HttpServletResponse getPathByHash(@PathParam("hash") String hash58, @PathParam("path") String inPath,
                                              @QueryParam("secret") String secret58,
                                              @QueryParam("theme") String theme) {
-        Security.requirePriorAuthorization(request, hash58, Service.WEBSITE, null);
-        return this.get(hash58, ResourceIdType.FILE_HASH, Service.WEBSITE, inPath, secret58, "/render/hash", true, false, theme);
+        if (!Settings.getInstance().isQDNAuthBypassEnabled())
+            Security.requirePriorAuthorization(request, hash58, Service.WEBSITE, null);
+
+        return this.get(hash58, ResourceIdType.FILE_HASH, Service.ARBITRARY_DATA, null, inPath, secret58, "/render/hash", true, false, theme);
     }
 
     @GET
@@ -178,10 +131,13 @@ public class RenderResource {
     public HttpServletResponse getPathByName(@PathParam("service") Service service,
                                              @PathParam("name") String name,
                                              @PathParam("path") String inPath,
+                                             @QueryParam("identifier") String identifier,
                                              @QueryParam("theme") String theme) {
-        Security.requirePriorAuthorization(request, name, service, null);
+        if (!Settings.getInstance().isQDNAuthBypassEnabled())
+            Security.requirePriorAuthorization(request, name, service, null);
+
         String prefix = String.format("/render/%s", service);
-        return this.get(name, ResourceIdType.NAME, service, inPath, null, prefix, true, true, theme);
+        return this.get(name, ResourceIdType.NAME, service, identifier, inPath, null, prefix, true, true, theme);
     }
 
     @GET
@@ -189,19 +145,22 @@ public class RenderResource {
     @SecurityRequirement(name = "apiKey")
     public HttpServletResponse getIndexByName(@PathParam("service") Service service,
                                               @PathParam("name") String name,
+                                              @QueryParam("identifier") String identifier,
                                               @QueryParam("theme") String theme) {
-        Security.requirePriorAuthorization(request, name, service, null);
+        if (!Settings.getInstance().isQDNAuthBypassEnabled())
+            Security.requirePriorAuthorization(request, name, service, null);
+
         String prefix = String.format("/render/%s", service);
-        return this.get(name, ResourceIdType.NAME, service, "/", null, prefix, true, true, theme);
+        return this.get(name, ResourceIdType.NAME, service, identifier, "/", null, prefix, true, true, theme);
     }
 
 
 
-    private HttpServletResponse get(String resourceId, ResourceIdType resourceIdType, Service service, String inPath,
-                                    String secret58, String prefix, boolean usePrefix, boolean async, String theme) {
+    private HttpServletResponse get(String resourceId, ResourceIdType resourceIdType, Service service, String identifier,
+                                    String inPath, String secret58, String prefix, boolean usePrefix, boolean async, String theme) {
 
-        ArbitraryDataRenderer renderer = new ArbitraryDataRenderer(resourceId, resourceIdType, service, inPath,
-                secret58, prefix, usePrefix, async, request, response, context);
+        ArbitraryDataRenderer renderer = new ArbitraryDataRenderer(resourceId, resourceIdType, service, identifier, inPath,
+                secret58, prefix, usePrefix, async, "render", request, response, context);
 
         if (theme != null) {
             renderer.setTheme(theme);

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

@@ -2,7 +2,9 @@ package org.qortal.api.websocket;
 
 import java.io.IOException;
 import java.io.StringWriter;
+import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 import java.util.concurrent.atomic.AtomicReference;
 
 import org.eclipse.jetty.websocket.api.Session;
@@ -21,6 +23,8 @@ import org.qortal.repository.DataException;
 import org.qortal.repository.Repository;
 import org.qortal.repository.RepositoryManager;
 
+import static org.qortal.data.chat.ChatMessage.Encoding;
+
 @WebSocket
 @SuppressWarnings("serial")
 public class ActiveChatsWebSocket extends ApiWebSocket {
@@ -62,7 +66,9 @@ public class ActiveChatsWebSocket extends ApiWebSocket {
 
 	@OnWebSocketMessage
 	public void onWebSocketMessage(Session session, String message) {
-		/* ignored */
+		if (Objects.equals(message, "ping")) {
+			session.getRemote().sendStringByFuture("pong");
+		}
 	}
 
 	private void onNotify(Session session, ChatTransactionData chatTransactionData, String ourAddress, AtomicReference<String> previousOutput) {
@@ -75,7 +81,7 @@ public class ActiveChatsWebSocket extends ApiWebSocket {
 		}
 
 		try (final Repository repository = RepositoryManager.getRepository()) {
-			ActiveChats activeChats = repository.getChatRepository().getActiveChats(ourAddress);
+			ActiveChats activeChats = repository.getChatRepository().getActiveChats(ourAddress, getTargetEncoding(session));
 
 			StringWriter stringWriter = new StringWriter();
 
@@ -93,4 +99,12 @@ public class ActiveChatsWebSocket extends ApiWebSocket {
 		}
 	}
 
+	private Encoding getTargetEncoding(Session session) {
+		// Default to Base58 if not specified, for backwards support
+		Map<String, List<String>> queryParams = session.getUpgradeRequest().getParameterMap();
+		List<String> encodingList = queryParams.get("encoding");
+		String encoding = (encodingList != null && encodingList.size() == 1) ? encodingList.get(0) : "BASE58";
+		return Encoding.valueOf(encoding);
+	}
+
 }

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

@@ -2,10 +2,7 @@ package org.qortal.api.websocket;
 
 import java.io.IOException;
 import java.io.StringWriter;
-import java.util.Arrays;
-import java.util.Collections;
-import java.util.List;
-import java.util.Map;
+import java.util.*;
 
 import org.eclipse.jetty.websocket.api.Session;
 import org.eclipse.jetty.websocket.api.WebSocketException;
@@ -22,6 +19,8 @@ import org.qortal.repository.DataException;
 import org.qortal.repository.Repository;
 import org.qortal.repository.RepositoryManager;
 
+import static org.qortal.data.chat.ChatMessage.Encoding;
+
 @WebSocket
 @SuppressWarnings("serial")
 public class ChatMessagesWebSocket extends ApiWebSocket {
@@ -35,6 +34,16 @@ public class ChatMessagesWebSocket extends ApiWebSocket {
 	@Override
 	public void onWebSocketConnect(Session session) {
 		Map<String, List<String>> queryParams = session.getUpgradeRequest().getParameterMap();
+		Encoding encoding = getTargetEncoding(session);
+
+		List<String> limitList = queryParams.get("limit");
+		Integer limit = (limitList != null && limitList.size() == 1) ? Integer.parseInt(limitList.get(0)) : null;
+
+		List<String> offsetList = queryParams.get("offset");
+		Integer offset = (offsetList != null && offsetList.size() == 1) ? Integer.parseInt(offsetList.get(0)) : null;
+
+		List<String> reverseList = queryParams.get("offset");
+		Boolean reverse = (reverseList != null && reverseList.size() == 1) ? Boolean.getBoolean(reverseList.get(0)) : null;
 
 		List<String> txGroupIds = queryParams.get("txGroupId");
 		if (txGroupIds != null && txGroupIds.size() == 1) {
@@ -47,7 +56,11 @@ public class ChatMessagesWebSocket extends ApiWebSocket {
 						txGroupId,
 						null,
 						null,
-						null, null, null);
+						null,
+						null,
+						null,
+						encoding,
+						limit, offset, reverse);
 
 				sendMessages(session, chatMessages);
 			} catch (DataException e) {
@@ -74,8 +87,12 @@ public class ChatMessagesWebSocket extends ApiWebSocket {
 					null,
 					null,
 					null,
+					null,
+					null,
 					involvingAddresses,
-					null, null, null);
+					null,
+					encoding,
+					limit, offset, reverse);
 
 			sendMessages(session, chatMessages);
 		} catch (DataException e) {
@@ -101,7 +118,9 @@ public class ChatMessagesWebSocket extends ApiWebSocket {
 
 	@OnWebSocketMessage
 	public void onWebSocketMessage(Session session, String message) {
-		/* ignored */
+		if (Objects.equals(message, "ping")) {
+			session.getRemote().sendStringByFuture("pong");
+		}
 	}
 
 	private void onNotify(Session session, ChatTransactionData chatTransactionData, int txGroupId) {
@@ -149,7 +168,7 @@ public class ChatMessagesWebSocket extends ApiWebSocket {
 		// Convert ChatTransactionData to ChatMessage
 		ChatMessage chatMessage;
 		try (final Repository repository = RepositoryManager.getRepository()) {
-			chatMessage = repository.getChatRepository().toChatMessage(chatTransactionData);
+			chatMessage = repository.getChatRepository().toChatMessage(chatTransactionData, getTargetEncoding(session));
 		} catch (DataException e) {
 			// No output this time?
 			return;
@@ -158,4 +177,12 @@ public class ChatMessagesWebSocket extends ApiWebSocket {
 		sendMessages(session, Collections.singletonList(chatMessage));
 	}
 
+	private Encoding getTargetEncoding(Session session) {
+		// Default to Base58 if not specified, for backwards support
+		Map<String, List<String>> queryParams = session.getUpgradeRequest().getParameterMap();
+		List<String> encodingList = queryParams.get("encoding");
+		String encoding = (encodingList != null && encodingList.size() == 1) ? encodingList.get(0) : "BASE58";
+		return Encoding.valueOf(encoding);
+	}
+
 }

src/main/java/org/qortal/arbitrary/ArbitraryDataBuilder.java

@@ -2,6 +2,7 @@ package org.qortal.arbitrary;
 
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
+import org.qortal.arbitrary.exception.DataNotPublishedException;
 import org.qortal.arbitrary.exception.MissingDataException;
 import org.qortal.arbitrary.metadata.ArbitraryDataMetadataCache;
 import org.qortal.arbitrary.misc.Service;
@@ -88,7 +89,7 @@ public class ArbitraryDataBuilder {
             if (latestPut == null) {
                 String message = String.format("Couldn't find PUT transaction for name %s, service %s and identifier %s",
                         this.name, this.service, this.identifierString());
-                throw new DataException(message);
+                throw new DataNotPublishedException(message);
             }
             this.latestPutTransaction = latestPut;
 

src/main/java/org/qortal/arbitrary/ArbitraryDataFile.java

@@ -4,6 +4,7 @@ import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.qortal.arbitrary.metadata.ArbitraryDataTransactionMetadata;
 import org.qortal.crypto.Crypto;
+import org.qortal.data.transaction.ArbitraryTransactionData;
 import org.qortal.repository.DataException;
 import org.qortal.settings.Settings;
 import org.qortal.utils.Base58;
@@ -15,7 +16,6 @@ import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.nio.file.StandardCopyOption;
 import java.util.*;
-import java.util.stream.Stream;
 
 import static java.util.Arrays.stream;
 import static java.util.stream.Collectors.toMap;
@@ -85,6 +85,7 @@ public class ArbitraryDataFile {
             return;
         }
 
+        this.chunks = new ArrayList<>();
         this.hash58 = Base58.encode(Crypto.digest(fileContent));
         this.signature = signature;
         LOGGER.trace(String.format("File digest: %s, size: %d bytes", this.hash58, fileContent.length));
@@ -111,6 +112,41 @@ public class ArbitraryDataFile {
         return ArbitraryDataFile.fromHash58(Base58.encode(hash), signature);
     }
 
+    public static ArbitraryDataFile fromRawData(byte[] data, byte[] signature) throws DataException {
+        if (data == null) {
+            return null;
+        }
+        return new ArbitraryDataFile(data, signature);
+    }
+
+    public static ArbitraryDataFile fromTransactionData(ArbitraryTransactionData transactionData) throws DataException {
+        ArbitraryDataFile arbitraryDataFile = null;
+        byte[] signature = transactionData.getSignature();
+        byte[] data = transactionData.getData();
+
+        if (data == null) {
+            return null;
+        }
+
+        // Create data file
+        switch (transactionData.getDataType()) {
+            case DATA_HASH:
+                arbitraryDataFile = ArbitraryDataFile.fromHash(data, signature);
+                break;
+
+            case RAW_DATA:
+                arbitraryDataFile = ArbitraryDataFile.fromRawData(data, signature);
+                break;
+        }
+
+        // Set metadata hash
+        if (arbitraryDataFile != null) {
+            arbitraryDataFile.setMetadataHash(transactionData.getMetadataHash());
+        }
+
+        return arbitraryDataFile;
+    }
+
     public static ArbitraryDataFile fromPath(Path path, byte[] signature) {
         if (path == null) {
             return null;
@@ -260,6 +296,11 @@ public class ArbitraryDataFile {
             this.chunks = new ArrayList<>();
 
             if (file != null) {
+                if (file.exists() && file.length() <= chunkSize) {
+                    // No need to split into chunks if we're already below the chunk size
+                    return 0;
+                }
+
                 try (FileInputStream fileInputStream = new FileInputStream(file);
                      BufferedInputStream bis = new BufferedInputStream(fileInputStream)) {
 
@@ -388,12 +429,15 @@ public class ArbitraryDataFile {
         return false;
     }
 
-    public boolean deleteAll() {
+    public boolean deleteAll(boolean deleteMetadata) {
         // Delete the complete file
         boolean fileDeleted = this.delete();
 
-        // Delete the metadata file
-        boolean metadataDeleted = this.deleteMetadata();
+        // Delete the metadata file if requested
+        boolean metadataDeleted = false;
+        if (deleteMetadata) {
+            metadataDeleted = this.deleteMetadata();
+        }
 
         // Delete the individual chunks
         boolean chunksDeleted = this.deleteAllChunks();
@@ -612,6 +656,22 @@ public class ArbitraryDataFile {
         return this.chunks.size();
     }
 
+    public int fileCount() {
+        int fileCount = this.chunkCount();
+        
+        if (fileCount == 0) {
+            // Transactions without any chunks can already be treated as a complete file
+            fileCount++;
+        }
+
+        if (this.getMetadataHash() != null) {
+            // Add the metadata file
+            fileCount++;
+        }
+
+        return fileCount;
+    }
+
     public List<ArbitraryDataFileChunk> getChunks() {
         return this.chunks;
     }

src/main/java/org/qortal/arbitrary/ArbitraryDataReader.java

@@ -4,6 +4,7 @@ import org.apache.commons.io.FileUtils;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 
+import org.qortal.arbitrary.exception.DataNotPublishedException;
 import org.qortal.arbitrary.exception.MissingDataException;
 import org.qortal.arbitrary.misc.Service;
 import org.qortal.controller.arbitrary.ArbitraryDataBuildManager;
@@ -18,10 +19,7 @@ import org.qortal.repository.RepositoryManager;
 import org.qortal.arbitrary.ArbitraryDataFile.*;
 import org.qortal.settings.Settings;
 import org.qortal.transform.Transformer;
-import org.qortal.utils.ArbitraryTransactionUtils;
-import org.qortal.utils.Base58;
-import org.qortal.utils.FilesystemUtils;
-import org.qortal.utils.ZipUtils;
+import org.qortal.utils.*;
 
 import javax.crypto.BadPaddingException;
 import javax.crypto.IllegalBlockSizeException;
@@ -59,6 +57,9 @@ public class ArbitraryDataReader {
     private int layerCount;
     private byte[] latestSignature;
 
+    // The resource being read
+    ArbitraryDataResource arbitraryDataResource = null;
+
     public ArbitraryDataReader(String resourceId, ResourceIdType resourceIdType, Service service, String identifier) {
         // Ensure names are always lowercase
         if (resourceIdType == ResourceIdType.NAME) {
@@ -115,6 +116,11 @@ public class ArbitraryDataReader {
         return new ArbitraryDataBuildQueueItem(this.resourceId, this.resourceIdType, this.service, this.identifier);
     }
 
+    private ArbitraryDataResource createArbitraryDataResource() {
+        return new ArbitraryDataResource(this.resourceId, this.resourceIdType, this.service, this.identifier);
+    }
+
+
     /**
      * loadAsynchronously
      *
@@ -162,6 +168,8 @@ public class ArbitraryDataReader {
                 return;
             }
 
+            this.arbitraryDataResource = this.createArbitraryDataResource();
+
             this.preExecute();
             this.deleteExistingFiles();
             this.fetch();
@@ -169,10 +177,18 @@ public class ArbitraryDataReader {
             this.uncompress();
             this.validate();
 
+        } catch (DataNotPublishedException e) {
+            if (e.getMessage() != null) {
+                // Log the message only, to avoid spamming the logs with a full stack trace
+                LOGGER.debug("DataNotPublishedException when trying to load QDN resource: {}", e.getMessage());
+            }
+            this.deleteWorkingDirectory();
+            throw e;
+
         } catch (DataException e) {
             LOGGER.info("DataException when trying to load QDN resource", e);
             this.deleteWorkingDirectory();
-            throw new DataException(e.getMessage());
+            throw e;
 
         } finally {
             this.postExecute();
@@ -343,11 +359,6 @@ public class ArbitraryDataReader {
             throw new DataException(String.format("Transaction data not found for signature %s", this.resourceId));
         }
 
-        // Load hashes
-        byte[] digest = transactionData.getData();
-        byte[] metadataHash = transactionData.getMetadataHash();
-        byte[] signature = transactionData.getSignature();
-
         // Load secret
         byte[] secret = transactionData.getSecret();
         if (secret != null) {
@@ -355,16 +366,14 @@ public class ArbitraryDataReader {
         }
 
         // Load data file(s)
-        ArbitraryDataFile arbitraryDataFile = ArbitraryDataFile.fromHash(digest, signature);
+        ArbitraryDataFile arbitraryDataFile = ArbitraryDataFile.fromTransactionData(transactionData);
         ArbitraryTransactionUtils.checkAndRelocateMiscFiles(transactionData);
-        arbitraryDataFile.setMetadataHash(metadataHash);
 
         if (!arbitraryDataFile.allFilesExist()) {
-            if (ArbitraryDataStorageManager.getInstance().isNameBlocked(transactionData.getName())) {
+            if (ListUtils.isNameBlocked(transactionData.getName())) {
                 throw new DataException(
                         String.format("Unable to request missing data for file %s because the name is blocked", arbitraryDataFile));
-            }
-            else {
+            } else {
                 // Ask the arbitrary data manager to fetch data for this transaction
                 String message;
                 if (this.canRequestMissingFiles) {
@@ -375,8 +384,7 @@ public class ArbitraryDataReader {
                     } else {
                         message = String.format("Unable to reissue request for missing file %s for signature %s due to rate limit. Please try again later.", arbitraryDataFile, Base58.encode(transactionData.getSignature()));
                     }
-                }
-                else {
+                } else {
                     message = String.format("Missing data for file %s", arbitraryDataFile);
                 }
 
@@ -386,21 +394,25 @@ public class ArbitraryDataReader {
             }
         }
 
-        if (arbitraryDataFile.allChunksExist() && !arbitraryDataFile.exists()) {
-            // We have all the chunks but not the complete file, so join them
-            arbitraryDataFile.join();
+        // Data hashes need some extra processing
+        if (transactionData.getDataType() == DataType.DATA_HASH) {
+            if (arbitraryDataFile.allChunksExist() && !arbitraryDataFile.exists()) {
+                // We have all the chunks but not the complete file, so join them
+                arbitraryDataFile.join();
+            }
+
+            // If the complete file still doesn't exist then something went wrong
+            if (!arbitraryDataFile.exists()) {
+                throw new IOException(String.format("File doesn't exist: %s", arbitraryDataFile));
+            }
+            // Ensure the complete hash matches the joined chunks
+            if (!Arrays.equals(arbitraryDataFile.digest(), transactionData.getData())) {
+                // Delete the invalid file
+                arbitraryDataFile.delete();
+                throw new DataException("Unable to validate complete file hash");
+            }
         }
 
-        // If the complete file still doesn't exist then something went wrong
-        if (!arbitraryDataFile.exists()) {
-            throw new IOException(String.format("File doesn't exist: %s", arbitraryDataFile));
-        }
-        // Ensure the complete hash matches the joined chunks
-        if (!Arrays.equals(arbitraryDataFile.digest(), digest)) {
-            // Delete the invalid file
-            arbitraryDataFile.delete();
-            throw new DataException("Unable to validate complete file hash");
-        }
         // Ensure the file's size matches the size reported by the transaction (throws a DataException if not)
         arbitraryDataFile.validateFileSize(transactionData.getSize());
 
@@ -427,7 +439,7 @@ public class ArbitraryDataReader {
         byte[] secret = this.secret58 != null ? Base58.decode(this.secret58) : null;
         if (secret != null && secret.length == Transformer.AES256_LENGTH) {
             try {
-                LOGGER.info("Decrypting using algorithm {}...", algorithm);
+                LOGGER.debug("Decrypting {} using algorithm {}...", this.arbitraryDataResource, algorithm);
                 Path unencryptedPath = Paths.get(this.workingPath.toString(), "zipped.zip");
                 SecretKey aesKey = new SecretKeySpec(secret, 0, secret.length, "AES");
                 AES.decryptFile(algorithm, aesKey, this.filePath.toString(), unencryptedPath.toString());
@@ -438,7 +450,7 @@ public class ArbitraryDataReader {
 
             } catch (NoSuchAlgorithmException | InvalidAlgorithmParameterException | NoSuchPaddingException
                     | BadPaddingException | IllegalBlockSizeException | IOException | InvalidKeyException e) {
-                LOGGER.info(String.format("Exception when decrypting using algorithm %s", algorithm), e);
+                LOGGER.info(String.format("Exception when decrypting %s using algorithm %s", this.arbitraryDataResource, algorithm), e);
                 throw new DataException(String.format("Unable to decrypt file at path %s using algorithm %s: %s", this.filePath, algorithm, e.getMessage()));
             }
         } else {

src/main/java/org/qortal/arbitrary/ArbitraryDataRenderer.java

@@ -2,6 +2,7 @@ package org.qortal.arbitrary;
 
 import com.google.common.io.Resources;
 import org.apache.commons.io.FileUtils;
+import org.apache.commons.lang3.ArrayUtils;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.qortal.api.HTMLParser;
@@ -34,28 +35,32 @@ public class ArbitraryDataRenderer {
     private final String resourceId;
     private final ResourceIdType resourceIdType;
     private final Service service;
+    private final String identifier;
     private String theme = "light";
     private String inPath;
     private final String secret58;
     private final String prefix;
     private final boolean usePrefix;
     private final boolean async;
+    private final String qdnContext;
     private final HttpServletRequest request;
     private final HttpServletResponse response;
     private final ServletContext context;
 
-    public ArbitraryDataRenderer(String resourceId, ResourceIdType resourceIdType, Service service, String inPath,
-                                 String secret58, String prefix, boolean usePrefix, boolean async,
+    public ArbitraryDataRenderer(String resourceId, ResourceIdType resourceIdType, Service service, String identifier,
+                                 String inPath, String secret58, String prefix, boolean usePrefix, boolean async, String qdnContext,
                                  HttpServletRequest request, HttpServletResponse response, ServletContext context) {
 
         this.resourceId = resourceId;
         this.resourceIdType = resourceIdType;
         this.service = service;
+        this.identifier = identifier != null ? identifier : "default";
         this.inPath = inPath;
         this.secret58 = secret58;
         this.prefix = prefix;
         this.usePrefix = usePrefix;
         this.async = async;
+        this.qdnContext = qdnContext;
         this.request = request;
         this.response = response;
         this.context = context;
@@ -71,14 +76,14 @@ public class ArbitraryDataRenderer {
             return ArbitraryDataRenderer.getResponse(response, 500, "QDN is disabled in settings");
         }
 
-        ArbitraryDataReader arbitraryDataReader = new ArbitraryDataReader(resourceId, resourceIdType, service, null);
+        ArbitraryDataReader arbitraryDataReader = new ArbitraryDataReader(resourceId, resourceIdType, service, identifier);
         arbitraryDataReader.setSecret58(secret58); // Optional, used for loading encrypted file hashes only
         try {
             if (!arbitraryDataReader.isCachedDataAvailable()) {
                 // If async is requested, show a loading screen whilst build is in progress
                 if (async) {
                     arbitraryDataReader.loadAsynchronously(false, 10);
-                    return this.getLoadingResponse(service, resourceId, theme);
+                    return this.getLoadingResponse(service, resourceId, identifier, theme);
                 }
 
                 // Otherwise, loop until we have data
@@ -111,23 +116,57 @@ public class ArbitraryDataRenderer {
         }
         String unzippedPath = path.toString();
 
+        // Set path automatically for single file resources (except for apps, which handle routing differently)
+        String[] files = ArrayUtils.removeElement(new File(unzippedPath).list(), ".qortal");
+        if (files.length == 1 && this.service != Service.APP) {
+            // This is a single file resource
+            inPath = files[0];
+        }
+
         try {
             String filename = this.getFilename(unzippedPath, inPath);
-            String filePath = Paths.get(unzippedPath, filename).toString();
+            Path filePath = Paths.get(unzippedPath, filename);
+
+            // If the file doesn't exist, we may need to route the request elsewhere, or cleanup
+            if (!Files.exists(filePath)) {
+                if (inPath.equals("/")) {
+                    // Delete the unzipped folder if no index file was found
+                    try {
+                        FileUtils.deleteDirectory(new File(unzippedPath));
+                    } catch (IOException e) {
+                        LOGGER.debug("Unable to delete directory: {}", unzippedPath, e);
+                    }
+                }
+
+                // If this is an app, then forward all unhandled requests to the index, to give the app the option to route it
+                if (this.service == Service.APP) {
+                    // Locate index file
+                    List<String> indexFiles = ArbitraryDataRenderer.indexFiles();
+                    for (String indexFile : indexFiles) {
+                        Path indexPath = Paths.get(unzippedPath, indexFile);
+                        if (Files.exists(indexPath)) {
+                            // Forward request to index file
+                            filePath = indexPath;
+                            filename = indexFile;
+                            break;
+                        }
+                    }
+                }
+            }
 
             if (HTMLParser.isHtmlFile(filename)) {
                 // HTML file - needs to be parsed
-                byte[] data = Files.readAllBytes(Paths.get(filePath)); // TODO: limit file size that can be read into memory
-                HTMLParser htmlParser = new HTMLParser(resourceId, inPath, prefix, usePrefix, data);
+                byte[] data = Files.readAllBytes(filePath); // TODO: limit file size that can be read into memory
+                HTMLParser htmlParser = new HTMLParser(resourceId, inPath, prefix, usePrefix, data, qdnContext, service, identifier, theme);
                 htmlParser.addAdditionalHeaderTags();
-                response.addHeader("Content-Security-Policy", "default-src 'self' 'unsafe-inline' 'unsafe-eval'; media-src 'self' blob:; img-src 'self' data: blob:;");
+                response.addHeader("Content-Security-Policy", "default-src 'self' 'unsafe-inline' 'unsafe-eval'; media-src 'self' data: blob:; img-src 'self' data: blob:;");
                 response.setContentType(context.getMimeType(filename));
                 response.setContentLength(htmlParser.getData().length);
                 response.getOutputStream().write(htmlParser.getData());
             }
             else {
                 // Regular file - can be streamed directly
-                File file = new File(filePath);
+                File file = filePath.toFile();
                 FileInputStream inputStream = new FileInputStream(file);
                 response.addHeader("Content-Security-Policy", "default-src 'self'");
                 response.setContentType(context.getMimeType(filename));
@@ -143,14 +182,6 @@ public class ArbitraryDataRenderer {
             return response;
         } catch (FileNotFoundException | NoSuchFileException e) {
             LOGGER.info("Unable to serve file: {}", e.getMessage());
-            if (inPath.equals("/")) {
-                // Delete the unzipped folder if no index file was found
-                try {
-                    FileUtils.deleteDirectory(new File(unzippedPath));
-                } catch (IOException ioException) {
-                    LOGGER.debug("Unable to delete directory: {}", unzippedPath, e);
-                }
-            }
         } catch (IOException e) {
             LOGGER.info("Unable to serve file at path {}: {}", inPath, e.getMessage());
         }
@@ -172,7 +203,7 @@ public class ArbitraryDataRenderer {
         return userPath;
     }
 
-    private HttpServletResponse getLoadingResponse(Service service, String name, String theme) {
+    private HttpServletResponse getLoadingResponse(Service service, String name, String identifier, String theme) {
         String responseString = "";
         URL url = Resources.getResource("loading/index.html");
         try {
@@ -181,6 +212,7 @@ public class ArbitraryDataRenderer {
             // Replace vars
             responseString = responseString.replace("%%SERVICE%%", service.toString());
             responseString = responseString.replace("%%NAME%%", name);
+            responseString = responseString.replace("%%IDENTIFIER%%", identifier);
             responseString = responseString.replace("%%THEME%%", theme);
 
         } catch (IOException e) {

src/main/java/org/qortal/arbitrary/ArbitraryDataResource.java

@@ -3,6 +3,7 @@ package org.qortal.arbitrary;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.qortal.arbitrary.ArbitraryDataFile.ResourceIdType;
+import org.qortal.arbitrary.exception.DataNotPublishedException;
 import org.qortal.arbitrary.metadata.ArbitraryDataTransactionMetadata;
 import org.qortal.arbitrary.misc.Service;
 import org.qortal.controller.arbitrary.ArbitraryDataBuildManager;
@@ -10,13 +11,13 @@ import org.qortal.controller.arbitrary.ArbitraryDataManager;
 import org.qortal.controller.arbitrary.ArbitraryDataStorageManager;
 import org.qortal.data.arbitrary.ArbitraryResourceStatus;
 import org.qortal.data.transaction.ArbitraryTransactionData;
-import org.qortal.list.ResourceListManager;
 import org.qortal.repository.DataException;
 import org.qortal.repository.Repository;
 import org.qortal.repository.RepositoryManager;
 import org.qortal.settings.Settings;
 import org.qortal.utils.ArbitraryTransactionUtils;
 import org.qortal.utils.FilesystemUtils;
+import org.qortal.utils.ListUtils;
 import org.qortal.utils.NTP;
 
 import java.io.IOException;
@@ -42,6 +43,7 @@ public class ArbitraryDataResource {
     private int layerCount;
     private Integer localChunkCount = null;
     private Integer totalChunkCount = null;
+    private boolean exists = false;
 
     public ArbitraryDataResource(String resourceId, ResourceIdType resourceIdType, Service service, String identifier) {
         this.resourceId = resourceId.toLowerCase();
@@ -60,6 +62,10 @@ public class ArbitraryDataResource {
         // Avoid this for "quick" statuses, to speed things up
         if (!quick) {
             this.calculateChunkCounts();
+
+            if (!this.exists) {
+                return new ArbitraryResourceStatus(Status.NOT_PUBLISHED, this.localChunkCount, this.totalChunkCount);
+            }
         }
 
         if (resourceIdType != ResourceIdType.NAME) {
@@ -68,8 +74,7 @@ public class ArbitraryDataResource {
         }
 
         // Check if the name is blocked
-        if (ResourceListManager.getInstance()
-                .listContains("blockedNames", this.resourceId, false)) {
+        if (ListUtils.isNameBlocked(this.resourceId)) {
             return new ArbitraryResourceStatus(Status.BLOCKED, this.localChunkCount, this.totalChunkCount);
         }
 
@@ -134,21 +139,20 @@ public class ArbitraryDataResource {
         return null;
     }
 
-    public boolean delete() {
+    public boolean delete(boolean deleteMetadata) {
         try {
             this.fetchTransactions();
+            if (this.transactions == null) {
+                return false;
+            }
 
             List<ArbitraryTransactionData> transactionDataList = new ArrayList<>(this.transactions);
 
             for (ArbitraryTransactionData transactionData : transactionDataList) {
-                byte[] hash = transactionData.getData();
-                byte[] metadataHash = transactionData.getMetadataHash();
-                byte[] signature = transactionData.getSignature();
-                ArbitraryDataFile arbitraryDataFile = ArbitraryDataFile.fromHash(hash, signature);
-                arbitraryDataFile.setMetadataHash(metadataHash);
+                ArbitraryDataFile arbitraryDataFile = ArbitraryDataFile.fromTransactionData(transactionData);
 
                 // Delete any chunks or complete files from each transaction
-                arbitraryDataFile.deleteAll();
+                arbitraryDataFile.deleteAll(deleteMetadata);
             }
 
             // Also delete cached data for the entire resource
@@ -192,6 +196,9 @@ public class ArbitraryDataResource {
 
         try {
             this.fetchTransactions();
+            if (this.transactions == null) {
+                return false;
+            }
 
             List<ArbitraryTransactionData> transactionDataList = new ArrayList<>(this.transactions);
 
@@ -211,6 +218,14 @@ public class ArbitraryDataResource {
     private void calculateChunkCounts() {
         try {
             this.fetchTransactions();
+            if (this.transactions == null) {
+                this.exists = false;
+                this.localChunkCount = 0;
+                this.totalChunkCount = 0;
+                return;
+            }
+
+            this.exists = true;
 
             List<ArbitraryTransactionData> transactionDataList = new ArrayList<>(this.transactions);
             int localChunkCount = 0;
@@ -230,6 +245,9 @@ public class ArbitraryDataResource {
     private boolean isRateLimited() {
         try {
             this.fetchTransactions();
+            if (this.transactions == null) {
+                return true;
+            }
 
             List<ArbitraryTransactionData> transactionDataList = new ArrayList<>(this.transactions);
 
@@ -253,6 +271,10 @@ public class ArbitraryDataResource {
     private boolean isDataPotentiallyAvailable() {
         try {
             this.fetchTransactions();
+            if (this.transactions == null) {
+                return false;
+            }
+
             Long now = NTP.getTime();
             if (now == null) {
                 return false;
@@ -284,6 +306,10 @@ public class ArbitraryDataResource {
     private boolean isDownloading() {
         try {
             this.fetchTransactions();
+            if (this.transactions == null) {
+                return false;
+            }
+
             Long now = NTP.getTime();
             if (now == null) {
                 return false;
@@ -325,7 +351,7 @@ public class ArbitraryDataResource {
             if (latestPut == null) {
                 String message = String.format("Couldn't find PUT transaction for name %s, service %s and identifier %s",
                         this.resourceId, this.service, this.identifierString());
-                throw new DataException(message);
+                throw new DataNotPublishedException(message);
             }
             this.latestPutTransaction = latestPut;
 
@@ -336,7 +362,10 @@ public class ArbitraryDataResource {
             this.transactions = transactionDataList;
             this.layerCount = transactionDataList.size();
 
-        } catch (DataException e) {
+        } catch (DataNotPublishedException e) {
+            // Ignore without logging
+        }
+        catch (DataException e) {
             LOGGER.info(String.format("Repository error when fetching transactions for resource %s: %s", this, e.getMessage()));
         }
     }

src/main/java/org/qortal/arbitrary/ArbitraryDataTransactionBuilder.java

@@ -9,6 +9,7 @@ import org.qortal.arbitrary.metadata.ArbitraryDataMetadataPatch;
 import org.qortal.arbitrary.metadata.ArbitraryDataTransactionMetadata;
 import org.qortal.arbitrary.misc.Category;
 import org.qortal.arbitrary.misc.Service;
+import org.qortal.crypto.AES;
 import org.qortal.crypto.Crypto;
 import org.qortal.data.PaymentData;
 import org.qortal.data.transaction.ArbitraryTransactionData;
@@ -46,6 +47,7 @@ public class ArbitraryDataTransactionBuilder {
     private static final double MAX_FILE_DIFF = 0.5f;
 
     private final String publicKey58;
+    private final long fee;
     private final Path path;
     private final String name;
     private Method method;
@@ -64,11 +66,12 @@ public class ArbitraryDataTransactionBuilder {
     private ArbitraryTransactionData arbitraryTransactionData;
     private ArbitraryDataFile arbitraryDataFile;
 
-    public ArbitraryDataTransactionBuilder(Repository repository, String publicKey58, Path path, String name,
+    public ArbitraryDataTransactionBuilder(Repository repository, String publicKey58, long fee, Path path, String name,
                                            Method method, Service service, String identifier,
                                            String title, String description, List<String> tags, Category category) {
         this.repository = repository;
         this.publicKey58 = publicKey58;
+        this.fee = fee;
         this.path = path;
         this.name = name;
         this.method = method;
@@ -179,6 +182,7 @@ public class ArbitraryDataTransactionBuilder {
                 for (ModifiedPath path : metadata.getModifiedPaths()) {
                     if (path.getDiffType() != DiffType.COMPLETE_FILE) {
                         atLeastOnePatch = true;
+                        break;
                     }
                 }
             }
@@ -187,6 +191,14 @@ public class ArbitraryDataTransactionBuilder {
                 return Method.PUT;
             }
 
+            // We can't use PATCH for on-chain data because this requires the .qortal directory, which can't be put on chain
+            final boolean isSingleFileResource = FilesystemUtils.isSingleFileResource(this.path, false);
+            final boolean shouldUseOnChainData = (isSingleFileResource && AES.getEncryptedFileSize(FilesystemUtils.getSingleFileContents(path).length) <= ArbitraryTransaction.MAX_DATA_SIZE);
+            if (shouldUseOnChainData) {
+                LOGGER.info("Data size is small enough to go on chain - using PUT");
+                return Method.PUT;
+            }
+
             // State is appropriate for a PATCH transaction
             return Method.PATCH;
         }
@@ -227,10 +239,12 @@ public class ArbitraryDataTransactionBuilder {
                 random.nextBytes(lastReference);
             }
 
-            Compression compression = Compression.ZIP;
+            // Single file resources are handled differently, especially for very small data payloads, as these go on chain
+            final boolean isSingleFileResource = FilesystemUtils.isSingleFileResource(path, false);
+            final boolean shouldUseOnChainData = (isSingleFileResource && AES.getEncryptedFileSize(FilesystemUtils.getSingleFileContents(path).length) <= ArbitraryTransaction.MAX_DATA_SIZE);
 
-            // FUTURE? Use zip compression for directories, or no compression for single files
-            // Compression compression = (path.toFile().isDirectory()) ? Compression.ZIP : Compression.NONE;
+            // Use zip compression if data isn't going on chain
+            Compression compression = shouldUseOnChainData ? Compression.NONE : Compression.ZIP;
 
             ArbitraryDataWriter arbitraryDataWriter = new ArbitraryDataWriter(path, name, service, identifier, method,
                     compression, title, description, tags, category);
@@ -248,45 +262,52 @@ public class ArbitraryDataTransactionBuilder {
                 throw new DataException("Arbitrary data file is null");
             }
 
-            // Get chunks metadata file
+            // Get metadata file
             ArbitraryDataFile metadataFile = arbitraryDataFile.getMetadataFile();
             if (metadataFile == null && arbitraryDataFile.chunkCount() > 1) {
                 throw new DataException(String.format("Chunks metadata data file is null but there are %d chunks", arbitraryDataFile.chunkCount()));
             }
 
-            String digest58 = arbitraryDataFile.digest58();
-            if (digest58 == null) {
-                LOGGER.error("Unable to calculate file digest");
-                throw new DataException("Unable to calculate file digest");
+            // Default to using a data hash, with data held off-chain
+            ArbitraryTransactionData.DataType dataType = ArbitraryTransactionData.DataType.DATA_HASH;
+            byte[] data = arbitraryDataFile.digest();
+
+            // For small, single-chunk resources, we can store the data directly on chain
+            if (shouldUseOnChainData && arbitraryDataFile.getBytes().length <= ArbitraryTransaction.MAX_DATA_SIZE && arbitraryDataFile.chunkCount() == 0) {
+                // Within allowed on-chain data size
+                dataType = DataType.RAW_DATA;
+                data = arbitraryDataFile.getBytes();
             }
 
             final BaseTransactionData baseTransactionData = new BaseTransactionData(now, Group.NO_GROUP,
-                    lastReference, creatorPublicKey, 0L, null);
+                    lastReference, creatorPublicKey, fee, null);
             final int size = (int) arbitraryDataFile.size();
             final int version = 5;
             final int nonce = 0;
             byte[] secret = arbitraryDataFile.getSecret();
-            final ArbitraryTransactionData.DataType dataType = ArbitraryTransactionData.DataType.DATA_HASH;
-            final byte[] digest = arbitraryDataFile.digest();
+
             final byte[] metadataHash = (metadataFile != null) ? metadataFile.getHash() : null;
             final List<PaymentData> payments = new ArrayList<>();
 
             ArbitraryTransactionData transactionData = new ArbitraryTransactionData(baseTransactionData,
-                    version, service, nonce, size, name, identifier, method,
-                    secret, compression, digest, dataType, metadataHash, payments);
+                    version, service.value, nonce, size, name, identifier, method,
+                    secret, compression, data, dataType, metadataHash, payments);
 
             this.arbitraryTransactionData = transactionData;
 
-        } catch (DataException e) {
+        } catch (DataException | IOException e) {
             if (arbitraryDataFile != null) {
-                arbitraryDataFile.deleteAll();
+                arbitraryDataFile.deleteAll(true);
             }
-            throw(e);
+            throw new DataException(e);
         }
 
     }
 
     private boolean isMetadataEqual(ArbitraryDataTransactionMetadata existingMetadata) {
+        if (existingMetadata == null) {
+            return !this.hasMetadata();
+        }
         if (!Objects.equals(existingMetadata.getTitle(), this.title)) {
             return false;
         }
@@ -302,6 +323,10 @@ public class ArbitraryDataTransactionBuilder {
         return true;
     }
 
+    private boolean hasMetadata() {
+        return (this.title != null || this.description != null || this.category != null || this.tags != null);
+    }
+
     public void computeNonce() throws DataException {
         if (this.arbitraryTransactionData == null) {
             throw new DataException("Arbitrary transaction data is required to compute nonce");
@@ -313,7 +338,7 @@ public class ArbitraryDataTransactionBuilder {
 
         Transaction.ValidationResult result = transaction.isValidUnconfirmed();
         if (result != Transaction.ValidationResult.OK) {
-            arbitraryDataFile.deleteAll();
+            arbitraryDataFile.deleteAll(true);
             throw new DataException(String.format("Arbitrary transaction invalid: %s", result));
         }
         LOGGER.info("Transaction is valid");

src/main/java/org/qortal/arbitrary/ArbitraryDataWriter.java

@@ -1,5 +1,7 @@
 package org.qortal.arbitrary;
 
+import com.j256.simplemagic.ContentInfo;
+import com.j256.simplemagic.ContentInfoUtil;
 import org.apache.commons.io.FileUtils;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
@@ -23,16 +25,15 @@ import javax.crypto.NoSuchPaddingException;
 import javax.crypto.SecretKey;
 import java.io.File;
 import java.io.IOException;
-import java.nio.file.Files;
-import java.nio.file.Path;
-import java.nio.file.Paths;
+import java.net.FileNameMap;
+import java.net.URLConnection;
+import java.nio.file.*;
 import java.security.InvalidAlgorithmParameterException;
 import java.security.InvalidKeyException;
 import java.security.NoSuchAlgorithmException;
-import java.util.ArrayList;
-import java.util.Iterator;
-import java.util.List;
-import java.util.Objects;
+import java.util.*;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 public class ArbitraryDataWriter {
 
@@ -50,6 +51,8 @@ public class ArbitraryDataWriter {
     private final String description;
     private final List<String> tags;
     private final Category category;
+    private List<String> files;
+    private String mimeType;
 
     private int chunkSize = ArbitraryDataFile.CHUNK_SIZE;
 
@@ -80,12 +83,15 @@ public class ArbitraryDataWriter {
         this.description = ArbitraryDataTransactionMetadata.limitDescription(description);
         this.tags = ArbitraryDataTransactionMetadata.limitTags(tags);
         this.category = category;
+        this.files = new ArrayList<>(); // Populated in buildFileList()
+        this.mimeType = null; // Populated in buildFileList()
     }
 
     public void save() throws IOException, DataException, InterruptedException, MissingDataException {
         try {
             this.preExecute();
             this.validateService();
+            this.buildFileList();
             this.process();
             this.compress();
             this.encrypt();
@@ -101,10 +107,9 @@ public class ArbitraryDataWriter {
     private void preExecute() throws DataException {
         this.checkEnabled();
 
-        // Enforce compression when uploading a directory
-        File file = new File(this.filePath.toString());
-        if (file.isDirectory() && compression == Compression.NONE) {
-            throw new DataException("Unable to upload a directory without compression");
+        // Enforce compression when uploading multiple files
+        if (!FilesystemUtils.isSingleFileResource(this.filePath, false) && compression == Compression.NONE) {
+            throw new DataException("Unable to publish multiple files without compression");
         }
 
         // Create temporary working directory
@@ -143,6 +148,48 @@ public class ArbitraryDataWriter {
         }
     }
 
+    private void buildFileList() throws IOException {
+        // Check if the path already points to a single file
+        boolean isSingleFile = this.filePath.toFile().isFile();
+        Path singleFilePath = null;
+        if (isSingleFile) {
+            this.files.add(this.filePath.getFileName().toString());
+            singleFilePath = this.filePath;
+        }
+        else {
+            // Multi file resources (or a single file in a directory) require a walk through the directory tree
+            try (Stream<Path> stream = Files.walk(this.filePath)) {
+                this.files = stream
+                        .filter(Files::isRegularFile)
+                        .map(p -> this.filePath.relativize(p).toString())
+                        .filter(s -> !s.isEmpty())
+                        .collect(Collectors.toList());
+
+                if (this.files.size() == 1) {
+                    singleFilePath = Paths.get(this.filePath.toString(), this.files.get(0));
+
+                    // Update filePath to point to the single file (instead of the directory containing the file)
+                    this.filePath = singleFilePath;
+                }
+            }
+        }
+
+        if (singleFilePath != null) {
+            // Single file resource, so try and determine the MIME type
+            ContentInfoUtil util = new ContentInfoUtil();
+            ContentInfo info = util.findMatch(singleFilePath.toFile());
+            if (info != null) {
+                // Attempt to extract MIME type from file contents
+                this.mimeType = info.getMimeType();
+            }
+            else {
+                // Fall back to using the filename
+                FileNameMap fileNameMap = URLConnection.getFileNameMap();
+                this.mimeType = fileNameMap.getContentTypeFor(singleFilePath.toFile().getName());
+            }
+        }
+    }
+
     private void process() throws DataException, IOException, MissingDataException {
         switch (this.method) {
 
@@ -269,9 +316,6 @@ public class ArbitraryDataWriter {
         if (chunkCount > 0) {
             LOGGER.info(String.format("Successfully split into %d chunk%s", chunkCount, (chunkCount == 1 ? "" : "s")));
         }
-        else {
-            throw new DataException("Unable to split file into chunks");
-        }
     }
 
     private void createMetadataFile() throws IOException, DataException {
@@ -285,6 +329,8 @@ public class ArbitraryDataWriter {
             metadata.setTags(this.tags);
             metadata.setCategory(this.category);
             metadata.setChunks(this.arbitraryDataFile.chunkHashList());
+            metadata.setFiles(this.files);
+            metadata.setMimeType(this.mimeType);
             metadata.write();
 
             // Create an ArbitraryDataFile from the JSON file (we don't have a signature yet)

src/main/java/org/qortal/arbitrary/exception/DataNotPublishedException.java

@@ -0,0 +1,22 @@
+package org.qortal.arbitrary.exception;
+
+import org.qortal.repository.DataException;
+
+public class DataNotPublishedException extends DataException {
+
+	public DataNotPublishedException() {
+	}
+
+	public DataNotPublishedException(String message) {
+		super(message);
+	}
+
+	public DataNotPublishedException(String message, Throwable cause) {
+		super(message, cause);
+	}
+
+	public DataNotPublishedException(Throwable cause) {
+		super(cause);
+	}
+
+}

src/main/java/org/qortal/arbitrary/metadata/ArbitraryDataMetadata.java

@@ -2,6 +2,7 @@ package org.qortal.arbitrary.metadata;
 
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
+import org.json.JSONException;
 import org.qortal.repository.DataException;
 
 import java.io.BufferedWriter;
@@ -34,7 +35,7 @@ public class ArbitraryDataMetadata {
         this.filePath = filePath;
     }
 
-    protected void readJson() throws DataException {
+    protected void readJson() throws DataException, JSONException {
         // To be overridden
     }
 
@@ -44,8 +45,13 @@ public class ArbitraryDataMetadata {
 
 
     public void read() throws IOException, DataException {
-        this.loadJson();
-        this.readJson();
+        try {
+            this.loadJson();
+            this.readJson();
+
+        } catch (JSONException e) {
+            throw new DataException(String.format("Unable to read JSON: %s", e.getMessage()));
+        }
     }
 
     public void write() throws IOException, DataException {

src/main/java/org/qortal/arbitrary/metadata/ArbitraryDataMetadataCache.java

@@ -1,5 +1,6 @@
 package org.qortal.arbitrary.metadata;
 
+import org.json.JSONException;
 import org.json.JSONObject;
 import org.qortal.repository.DataException;
 import org.qortal.utils.Base58;
@@ -22,7 +23,7 @@ public class ArbitraryDataMetadataCache extends ArbitraryDataQortalMetadata {
     }
 
     @Override
-    protected void readJson() throws DataException {
+    protected void readJson() throws DataException, JSONException {
         if (this.jsonString == null) {
             throw new DataException("Patch JSON string is null");
         }

src/main/java/org/qortal/arbitrary/metadata/ArbitraryDataMetadataPatch.java

@@ -3,6 +3,7 @@ package org.qortal.arbitrary.metadata;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.json.JSONArray;
+import org.json.JSONException;
 import org.json.JSONObject;
 import org.qortal.arbitrary.ArbitraryDataDiff.*;
 import org.qortal.repository.DataException;
@@ -40,7 +41,7 @@ public class ArbitraryDataMetadataPatch extends ArbitraryDataQortalMetadata {
     }
 
     @Override
-    protected void readJson() throws DataException {
+    protected void readJson() throws DataException, JSONException {
         if (this.jsonString == null) {
             throw new DataException("Patch JSON string is null");
         }

src/main/java/org/qortal/arbitrary/metadata/ArbitraryDataQortalMetadata.java

@@ -2,6 +2,7 @@ package org.qortal.arbitrary.metadata;
 
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
+import org.json.JSONException;
 import org.qortal.repository.DataException;
 
 import java.io.BufferedWriter;
@@ -46,20 +47,6 @@ public class ArbitraryDataQortalMetadata extends ArbitraryDataMetadata {
         return null;
     }
 
-    protected void readJson() throws DataException {
-        // To be overridden
-    }
-
-    protected void buildJson() {
-        // To be overridden
-    }
-
-
-    @Override
-    public void read() throws IOException, DataException {
-        this.loadJson();
-        this.readJson();
-    }
 
     @Override
     public void write() throws IOException, DataException {
@@ -94,9 +81,4 @@ public class ArbitraryDataQortalMetadata extends ArbitraryDataMetadata {
         }
     }
 
-
-    public String getJsonString() {
-        return this.jsonString;
-    }
-
 }

src/main/java/org/qortal/arbitrary/metadata/ArbitraryDataTransactionMetadata.java

@@ -1,6 +1,7 @@
 package org.qortal.arbitrary.metadata;
 
 import org.json.JSONArray;
+import org.json.JSONException;
 import org.json.JSONObject;
 import org.qortal.arbitrary.misc.Category;
 import org.qortal.repository.DataException;
@@ -19,9 +20,11 @@ public class ArbitraryDataTransactionMetadata extends ArbitraryDataMetadata {
     private String description;
     private List<String> tags;
     private Category category;
+    private List<String> files;
+    private String mimeType;
 
     private static int MAX_TITLE_LENGTH = 80;
-    private static int MAX_DESCRIPTION_LENGTH = 500;
+    private static int MAX_DESCRIPTION_LENGTH = 240;
     private static int MAX_TAG_LENGTH = 20;
     private static int MAX_TAGS_COUNT = 5;
 
@@ -31,7 +34,7 @@ public class ArbitraryDataTransactionMetadata extends ArbitraryDataMetadata {
     }
 
     @Override
-    protected void readJson() throws DataException {
+    protected void readJson() throws DataException, JSONException {
         if (this.jsonString == null) {
             throw new DataException("Transaction metadata JSON string is null");
         }
@@ -77,6 +80,24 @@ public class ArbitraryDataTransactionMetadata extends ArbitraryDataMetadata {
             }
             this.chunks = chunksList;
         }
+
+        List<String> filesList = new ArrayList<>();
+        if (metadata.has("files")) {
+            JSONArray files = metadata.getJSONArray("files");
+            if (files != null) {
+                for (int i=0; i<files.length(); i++) {
+                    String tag = files.getString(i);
+                    if (tag != null) {
+                        filesList.add(tag);
+                    }
+                }
+            }
+            this.files = filesList;
+        }
+
+        if (metadata.has("mimeType")) {
+            this.mimeType = metadata.getString("mimeType");
+        }
     }
 
     @Override
@@ -111,6 +132,18 @@ public class ArbitraryDataTransactionMetadata extends ArbitraryDataMetadata {
         }
         outer.put("chunks", chunks);
 
+        JSONArray files = new JSONArray();
+        if (this.files != null) {
+            for (String file : this.files) {
+                files.put(file);
+            }
+        }
+        outer.put("files", files);
+
+        if (this.mimeType != null && !this.mimeType.isEmpty()) {
+            outer.put("mimeType", this.mimeType);
+        }
+
         this.jsonString = outer.toString(2);
         LOGGER.trace("Transaction metadata: {}", this.jsonString);
     }
@@ -156,6 +189,22 @@ public class ArbitraryDataTransactionMetadata extends ArbitraryDataMetadata {
         return this.category;
     }
 
+    public void setFiles(List<String> files) {
+        this.files = files;
+    }
+
+    public List<String> getFiles() {
+        return this.files;
+    }
+
+    public void setMimeType(String mimeType) {
+        this.mimeType = mimeType;
+    }
+
+    public String getMimeType() {
+        return this.mimeType;
+    }
+
     public boolean containsChunk(byte[] chunk) {
         for (byte[] c : this.chunks) {
             if (Arrays.equals(c, chunk)) {

src/main/java/org/qortal/arbitrary/misc/Service.java

@@ -8,21 +8,53 @@ import org.qortal.utils.FilesystemUtils;
 
 import java.io.File;
 import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
-import java.util.List;
-import java.util.Map;
-import java.util.Objects;
+import java.util.*;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
 
 import static java.util.Arrays.stream;
 import static java.util.stream.Collectors.toMap;
 
 public enum Service {
-    AUTO_UPDATE(1, false, null, null),
-    ARBITRARY_DATA(100, false, null, null),
-    WEBSITE(200, true, null, null) {
+    AUTO_UPDATE(1, false, null, false, null),
+    ARBITRARY_DATA(100, false, null, false, null),
+    QCHAT_ATTACHMENT(120, true, 1024*1024L, true, null) {
         @Override
-        public ValidationResult validate(Path path) {
+        public ValidationResult validate(Path path) throws IOException {
+            ValidationResult superclassResult = super.validate(path);
+            if (superclassResult != ValidationResult.OK) {
+                return superclassResult;
+            }
+
+            File[] files = path.toFile().listFiles();
+            // If already a single file, replace the list with one that contains that file only
+            if (files == null && path.toFile().isFile()) {
+                files = new File[] { path.toFile() };
+            }
+            // Now validate the file's extension
+            if (files != null && files[0] != null) {
+                final String extension = FilenameUtils.getExtension(files[0].getName()).toLowerCase();
+                // We must allow blank file extensions because these are used by data published from a plaintext or base64-encoded string
+                final List<String> allowedExtensions = Arrays.asList("zip", "pdf", "txt", "odt", "ods", "doc", "docx", "xls", "xlsx", "ppt", "pptx", "");
+                if (extension == null || !allowedExtensions.contains(extension)) {
+                    return ValidationResult.INVALID_FILE_EXTENSION;
+                }
+            }
+            return ValidationResult.OK;
+        }
+    },
+    WEBSITE(200, true, null, false, null) {
+        @Override
+        public ValidationResult validate(Path path) throws IOException {
+            ValidationResult superclassResult = super.validate(path);
+            if (superclassResult != ValidationResult.OK) {
+                return superclassResult;
+            }
+
             // Custom validation function to require an index HTML file in the root directory
             List<String> fileNames = ArbitraryDataRenderer.indexFiles();
             String[] files = path.toFile().list();
@@ -37,28 +69,61 @@ public enum Service {
             return ValidationResult.MISSING_INDEX_FILE;
         }
     },
-    GIT_REPOSITORY(300, false, null, null),
-    IMAGE(400, true, 10*1024*1024L, null),
-    THUMBNAIL(410, true, 500*1024L, null),
-    QCHAT_IMAGE(420, true, 500*1024L, null),
-    VIDEO(500, false, null, null),
-    AUDIO(600, false, null, null),
-    BLOG(700, false, null, null),
-    BLOG_POST(777, false, null, null),
-    BLOG_COMMENT(778, false, null, null),
-    DOCUMENT(800, false, null, null),
-    LIST(900, true, null, null),
-    PLAYLIST(910, true, null, null),
-    APP(1000, false, null, null),
-    METADATA(1100, false, null, null),
-    GIF_REPOSITORY(1200, true, 25*1024*1024L, null) {
+    GIT_REPOSITORY(300, false, null, false, null),
+    IMAGE(400, true, 10*1024*1024L, true, null),
+    THUMBNAIL(410, true, 500*1024L, true, null),
+    QCHAT_IMAGE(420, true, 500*1024L, true, null),
+    VIDEO(500, false, null, true, null),
+    AUDIO(600, false, null, true, null),
+    QCHAT_AUDIO(610, true, 10*1024*1024L, true, null),
+    QCHAT_VOICE(620, true, 10*1024*1024L, true, null),
+    BLOG(700, false, null, false, null),
+    BLOG_POST(777, false, null, true, null),
+    BLOG_COMMENT(778, false, null, true, null),
+    DOCUMENT(800, false, null, true, null),
+    LIST(900, true, null, true, null),
+    PLAYLIST(910, true, null, true, null),
+    APP(1000, true, 50*1024*1024L, false, null),
+    METADATA(1100, false, null, true, null),
+    JSON(1110, true, 25*1024L, true, null) {
         @Override
-        public ValidationResult validate(Path path) {
+        public ValidationResult validate(Path path) throws IOException {
+            ValidationResult superclassResult = super.validate(path);
+            if (superclassResult != ValidationResult.OK) {
+                return superclassResult;
+            }
+
+            // Require valid JSON
+            byte[] data = FilesystemUtils.getSingleFileContents(path);
+            String json = new String(data, StandardCharsets.UTF_8);
+            try {
+                objectMapper.readTree(json);
+                return ValidationResult.OK;
+            } catch (IOException e) {
+                return ValidationResult.INVALID_CONTENT;
+            }
+        }
+    },
+    GIF_REPOSITORY(1200, true, 25*1024*1024L, false, null) {
+        @Override
+        public ValidationResult validate(Path path) throws IOException {
+            ValidationResult superclassResult = super.validate(path);
+            if (superclassResult != ValidationResult.OK) {
+                return superclassResult;
+            }
+
             // Custom validation function to require .gif files only, and at least 1
             int gifCount = 0;
             File[] files = path.toFile().listFiles();
+            // If already a single file, replace the list with one that contains that file only
+            if (files == null && path.toFile().isFile()) {
+                files = new File[] { path.toFile() };
+            }
             if (files != null) {
                 for (File file : files) {
+                    if (file.getName().equals(".qortal")) {
+                        continue;
+                    }
                     if (file.isDirectory()) {
                         return ValidationResult.DIRECTORIES_NOT_ALLOWED;
                     }
@@ -79,15 +144,20 @@ public enum Service {
     public final int value;
     private final boolean requiresValidation;
     private final Long maxSize;
+    private final boolean single;
     private final List<String> requiredKeys;
 
     private static final Map<Integer, Service> map = stream(Service.values())
             .collect(toMap(service -> service.value, service -> service));
 
-    Service(int value, boolean requiresValidation, Long maxSize, List<String> requiredKeys) {
+    // For JSON validation
+    private static final ObjectMapper objectMapper = new ObjectMapper();
+
+    Service(int value, boolean requiresValidation, Long maxSize, boolean single, List<String> requiredKeys) {
         this.value = value;
         this.requiresValidation = requiresValidation;
         this.maxSize = maxSize;
+        this.single = single;
         this.requiredKeys = requiredKeys;
     }
 
@@ -106,6 +176,11 @@ public enum Service {
             }
         }
 
+        // Validate file count if needed
+        if (this.single && data == null) {
+            return ValidationResult.INVALID_FILE_COUNT;
+        }
+
         // Validate required keys if needed
         if (this.requiredKeys != null) {
             if (data == null) {
@@ -143,7 +218,9 @@ public enum Service {
         MISSING_INDEX_FILE(4),
         DIRECTORIES_NOT_ALLOWED(5),
         INVALID_FILE_EXTENSION(6),
-        MISSING_DATA(7);
+        MISSING_DATA(7),
+        INVALID_FILE_COUNT(8),
+        INVALID_CONTENT(9);
 
         public final int value;
 

src/main/java/org/qortal/block/Block.java

@@ -657,6 +657,10 @@ public class Block {
 		return this.atStates;
 	}
 
+	public byte[] getAtStatesHash() {
+		return this.atStatesHash;
+	}
+
 	/**
 	 * Return expanded info on block's online accounts.
 	 * <p>
@@ -1522,6 +1526,9 @@ public class Block {
 		// Batch update in repository
 		repository.getAccountRepository().modifyMintedBlockCounts(allUniqueExpandedAccounts.stream().map(AccountData::getAddress).collect(Collectors.toList()), +1);
 
+		// Keep track of level bumps in case we need to apply to other entries
+		Map<String, Integer> bumpedAccounts = new HashMap<>();
+
 		// Local changes and also checks for level bump
 		for (AccountData accountData : allUniqueExpandedAccounts) {
 			// Adjust count locally (in Java)
@@ -1535,6 +1542,7 @@ public class Block {
 					if (newLevel > accountData.getLevel()) {
 						// Account has increased in level!
 						accountData.setLevel(newLevel);
+						bumpedAccounts.put(accountData.getAddress(), newLevel);
 						repository.getAccountRepository().setLevel(accountData);
 						LOGGER.trace(() -> String.format("Block minter %s bumped to level %d", accountData.getAddress(), accountData.getLevel()));
 					}
@@ -1542,6 +1550,25 @@ public class Block {
 					break;
 				}
 		}
+
+		// Also bump other entries if need be
+		if (!bumpedAccounts.isEmpty()) {
+			for (ExpandedAccount expandedAccount : expandedAccounts) {
+				Integer newLevel = bumpedAccounts.get(expandedAccount.mintingAccountData.getAddress());
+				if (newLevel != null && expandedAccount.mintingAccountData.getLevel() != newLevel) {
+					expandedAccount.mintingAccountData.setLevel(newLevel);
+					LOGGER.trace("Also bumped {} to level {}", expandedAccount.mintingAccountData.getAddress(), newLevel);
+				}
+
+				if (!expandedAccount.isRecipientAlsoMinter) {
+					newLevel = bumpedAccounts.get(expandedAccount.recipientAccountData.getAddress());
+					if (newLevel != null && expandedAccount.recipientAccountData.getLevel() != newLevel) {
+						expandedAccount.recipientAccountData.setLevel(newLevel);
+						LOGGER.trace("Also bumped {} to level {}", expandedAccount.recipientAccountData.getAddress(), newLevel);
+					}
+				}
+			}
+		}
 	}
 
 	protected void processBlockRewards() throws DataException {

src/main/java/org/qortal/block/BlockChain.java

@@ -76,7 +76,10 @@ public class BlockChain {
 		disableReferenceTimestamp,
 		increaseOnlineAccountsDifficultyTimestamp,
 		onlineAccountMinterLevelValidationHeight,
-		selfSponsorshipAlgoV1Height;
+		selfSponsorshipAlgoV1Height,
+		feeValidationFixTimestamp,
+		chatReferenceTimestamp,
+		arbitraryOptionalFeeTimestamp;
 	}
 
 	// Custom transaction fees
@@ -98,6 +101,13 @@ public class BlockChain {
 	/** Whether only one registered name is allowed per account. */
 	private boolean oneNamePerAccount = false;
 
+	/** Checkpoints */
+	public static class Checkpoint {
+		public int height;
+		public String signature;
+	}
+	private List<Checkpoint> checkpoints;
+
 	/** Block rewards by block height */
 	public static class RewardByHeight {
 		public int height;
@@ -379,6 +389,10 @@ public class BlockChain {
 		return this.oneNamePerAccount;
 	}
 
+	public List<Checkpoint> getCheckpoints() {
+		return this.checkpoints;
+	}
+
 	public List<RewardByHeight> getBlockRewardsByHeight() {
 		return this.rewardsByHeight;
 	}
@@ -501,6 +515,18 @@ public class BlockChain {
 		return this.featureTriggers.get(FeatureTrigger.onlineAccountMinterLevelValidationHeight.name()).intValue();
 	}
 
+	public long getFeeValidationFixTimestamp() {
+		return this.featureTriggers.get(FeatureTrigger.feeValidationFixTimestamp.name()).longValue();
+	}
+
+	public long getChatReferenceTimestamp() {
+		return this.featureTriggers.get(FeatureTrigger.chatReferenceTimestamp.name()).longValue();
+	}
+
+	public long getArbitraryOptionalFeeTimestamp() {
+		return this.featureTriggers.get(FeatureTrigger.arbitraryOptionalFeeTimestamp.name()).longValue();
+	}
+
 
 	// More complex getters for aspects that change by height or timestamp
 
@@ -669,6 +695,7 @@ public class BlockChain {
 
 		boolean isTopOnly = Settings.getInstance().isTopOnly();
 		boolean archiveEnabled = Settings.getInstance().isArchiveEnabled();
+		boolean isLite = Settings.getInstance().isLite();
 		boolean canBootstrap = Settings.getInstance().getBootstrap();
 		boolean needsArchiveRebuild = false;
 		BlockData chainTip;
@@ -689,22 +716,44 @@ public class BlockChain {
 					}
 				}
 			}
+
+			// Validate checkpoints
+			// Limited to topOnly nodes for now, in order to reduce risk, and to solve a real-world problem with divergent topOnly nodes
+			// TODO: remove the isTopOnly conditional below once this feature has had more testing time
+			if (isTopOnly && !isLite) {
+				List<Checkpoint> checkpoints = BlockChain.getInstance().getCheckpoints();
+				for (Checkpoint checkpoint : checkpoints) {
+					BlockData blockData = repository.getBlockRepository().fromHeight(checkpoint.height);
+					if (blockData == null) {
+						// Try the archive
+						blockData = repository.getBlockArchiveRepository().fromHeight(checkpoint.height);
+					}
+					if (blockData == null) {
+						LOGGER.trace("Couldn't find block for height {}", checkpoint.height);
+						// This is likely due to the block being pruned, so is safe to ignore.
+						// Continue, as there might be other blocks we can check more definitively.
+						continue;
+					}
+
+					byte[] signature = Base58.decode(checkpoint.signature);
+					if (!Arrays.equals(signature, blockData.getSignature())) {
+						LOGGER.info("Error: block at height {} with signature {} doesn't match checkpoint sig: {}. Bootstrapping...", checkpoint.height, Base58.encode(blockData.getSignature()), checkpoint.signature);
+						needsArchiveRebuild = true;
+						break;
+					}
+					LOGGER.info("Block at height {} matches checkpoint signature", blockData.getHeight());
+				}
+			}
+
 		}
 
-		boolean hasBlocks = (chainTip != null && chainTip.getHeight() > 1);
+		// Check first block is Genesis Block
+		if (!isGenesisBlockValid() || needsArchiveRebuild) {
+			try {
+				rebuildBlockchain();
 
-		if (isTopOnly && hasBlocks) {
-			// Top-only mode is enabled and we have blocks, so it's possible that the genesis block has been pruned
-			// It's best not to validate it, and there's no real need to
-		} else {
-			// Check first block is Genesis Block
-			if (!isGenesisBlockValid() || needsArchiveRebuild) {
-				try {
-					rebuildBlockchain();
-
-				} catch (InterruptedException e) {
-					throw new DataException(String.format("Interrupted when trying to rebuild blockchain: %s", e.getMessage()));
-				}
+			} catch (InterruptedException e) {
+				throw new DataException(String.format("Interrupted when trying to rebuild blockchain: %s", e.getMessage()));
 			}
 		}
 
@@ -713,9 +762,7 @@ public class BlockChain {
 		try (final Repository repository = RepositoryManager.getRepository()) {
 			repository.checkConsistency();
 
-			// Set the number of blocks to validate based on the pruned state of the chain
-			// If pruned, subtract an extra 10 to allow room for error
-			int blocksToValidate = (isTopOnly || archiveEnabled) ? Settings.getInstance().getPruneBlockLimit() - 10 : 1440;
+			int blocksToValidate = Math.min(Settings.getInstance().getPruneBlockLimit() - 10, 1440);
 
 			int startHeight = Math.max(repository.getBlockRepository().getBlockchainHeight() - blocksToValidate, 1);
 			BlockData detachedBlockData = repository.getBlockRepository().getDetachedBlockSignature(startHeight);

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

@@ -293,4 +293,77 @@ public class AutoUpdate extends Thread {
 		}
 	}
 
+	public static boolean attemptRestart() {
+		LOGGER.info(String.format("Restarting node..."));
+
+		// Give repository a chance to backup in case things go badly wrong (if enabled)
+		if (Settings.getInstance().getRepositoryBackupInterval() > 0) {
+			try {
+				// Timeout if the database isn't ready for backing up after 60 seconds
+				long timeout = 60 * 1000L;
+				RepositoryManager.backup(true, "backup", timeout);
+
+			} catch (TimeoutException e) {
+				LOGGER.info("Attempt to backup repository failed due to timeout: {}", e.getMessage());
+				// Continue with the node restart anyway...
+			}
+		}
+
+		// Call ApplyUpdate to end this process (unlocking current JAR so it can be replaced)
+		String javaHome = System.getProperty("java.home");
+		LOGGER.debug(String.format("Java home: %s", javaHome));
+
+		Path javaBinary = Paths.get(javaHome, "bin", "java");
+		LOGGER.debug(String.format("Java binary: %s", javaBinary));
+
+		try {
+			List<String> javaCmd = new ArrayList<>();
+			// Java runtime binary itself
+			javaCmd.add(javaBinary.toString());
+
+			// JVM arguments
+			javaCmd.addAll(ManagementFactory.getRuntimeMXBean().getInputArguments());
+
+			// Disable, but retain, any -agentlib JVM arg as sub-process might fail if it tries to reuse same port
+			javaCmd = javaCmd.stream()
+					.map(arg -> arg.replace("-agentlib", AGENTLIB_JVM_HOLDER_ARG))
+					.collect(Collectors.toList());
+
+			// Remove JNI options as they won't be supported by command-line 'java'
+			// These are typically added by the AdvancedInstaller Java launcher EXE
+			javaCmd.removeAll(Arrays.asList("abort", "exit", "vfprintf"));
+
+			// Call ApplyUpdate using JAR
+			javaCmd.addAll(Arrays.asList("-cp", JAR_FILENAME, ApplyUpdate.class.getCanonicalName()));
+
+			// Add command-line args saved from start-up
+			String[] savedArgs = Controller.getInstance().getSavedArgs();
+			if (savedArgs != null)
+				javaCmd.addAll(Arrays.asList(savedArgs));
+
+			LOGGER.info(String.format("Restarting node with: %s", String.join(" ", javaCmd)));
+
+			SysTray.getInstance().showMessage(Translator.INSTANCE.translate("SysTray", "AUTO_UPDATE"), //TODO
+					Translator.INSTANCE.translate("SysTray", "APPLYING_UPDATE_AND_RESTARTING"), //TODO
+					MessageType.INFO);
+
+			ProcessBuilder processBuilder = new ProcessBuilder(javaCmd);
+
+			// New process will inherit our stdout and stderr
+			processBuilder.redirectOutput(ProcessBuilder.Redirect.INHERIT);
+			processBuilder.redirectError(ProcessBuilder.Redirect.INHERIT);
+
+			Process process = processBuilder.start();
+
+			// Nothing to pipe to new process, so close output stream (process's stdin)
+			process.getOutputStream().close();
+
+			return true; // restarting node OK
+		} catch (Exception e) {
+			LOGGER.error(String.format("Failed to restart node: %s", e.getMessage()));
+
+			return true; // repo was okay, even if applying update failed
+		}
+	}
+
 }

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

@@ -63,8 +63,8 @@ public class BlockMinter extends Thread {
 	public void run() {
 		Thread.currentThread().setName("BlockMinter");
 
-		if (Settings.getInstance().isLite()) {
-			// Lite nodes do not mint
+		if (Settings.getInstance().isTopOnly() || Settings.getInstance().isLite()) {
+			// Top only and lite nodes do not sign blocks
 			return;
 		}
 		if (Settings.getInstance().getWipeUnconfirmedOnStart()) {
@@ -432,6 +432,10 @@ public class BlockMinter extends Thread {
 							// Unable to process block - report and discard
 							LOGGER.error("Unable to process newly minted block?", e);
 							newBlocks.clear();
+						} catch (ArithmeticException e) {
+							// Unable to process block - report and discard
+							LOGGER.error("Unable to process newly minted block?", e);
+							newBlocks.clear();
 						}
 					} finally {
 						blockchainLock.unlock();

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

@@ -400,12 +400,8 @@ public class Controller extends Thread {
 			RepositoryFactory repositoryFactory = new HSQLDBRepositoryFactory(getRepositoryUrl());
 			RepositoryManager.setRepositoryFactory(repositoryFactory);
 			RepositoryManager.setRequestedCheckpoint(Boolean.TRUE);
-
-			try (final Repository repository = RepositoryManager.getRepository()) {
-				RepositoryManager.archive(repository);
-				RepositoryManager.prune(repository);
-			}
-		} catch (DataException e) {
+		}
+		catch (DataException e) {
 			// If exception has no cause then repository is in use by some other process.
 			if (e.getCause() == null) {
 				LOGGER.info("Repository in use by another process?");
@@ -769,6 +765,16 @@ public class Controller extends Thread {
 		}
 	};
 
+	public static final Predicate<Peer> wasRecentlyTooDivergent = peer -> {
+		Long now = NTP.getTime();
+		Long peerLastTooDivergentTime = peer.getLastTooDivergentTime();
+		if (now == null || peerLastTooDivergentTime == null)
+			return false;
+
+		// Exclude any peers that were TOO_DIVERGENT in the last 5 mins
+		return (now - peerLastTooDivergentTime < 5 * 60 * 1000L);
+	};
+
 	private long getRandomRepositoryMaintenanceInterval() {
 		final long minInterval = Settings.getInstance().getRepositoryMaintenanceMinInterval();
 		final long maxInterval = Settings.getInstance().getRepositoryMaintenanceMaxInterval();
@@ -1369,9 +1375,24 @@ public class Controller extends Thread {
 			// If we have no block data, we should check the archive in case it's there
 			if (blockData == null) {
 				if (Settings.getInstance().isArchiveEnabled()) {
-					byte[] bytes = BlockArchiveReader.getInstance().fetchSerializedBlockBytesForSignature(signature, true, repository);
-					if (bytes != null) {
-						CachedBlockMessage blockMessage = new CachedBlockMessage(bytes);
+					Triple<byte[], Integer, Integer> serializedBlock = BlockArchiveReader.getInstance().fetchSerializedBlockBytesForSignature(signature, true, repository);
+					if (serializedBlock != null) {
+						byte[] bytes = serializedBlock.getA();
+						Integer serializationVersion = serializedBlock.getB();
+
+						Message blockMessage;
+						switch (serializationVersion) {
+							case 1:
+								blockMessage = new CachedBlockMessage(bytes);
+								break;
+
+							case 2:
+								blockMessage = new CachedBlockV2Message(bytes);
+								break;
+
+							default:
+								return;
+						}
 						blockMessage.setId(message.getId());
 
 						// This call also causes the other needed data to be pulled in from repository

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

@@ -163,7 +163,7 @@ public class PirateChainWalletController extends Thread {
 
             // Library not found, so check if we've fetched the resource from QDN
             ArbitraryTransactionData t = this.getTransactionData(repository);
-            if (t == null) {
+            if (t == null || t.getService() == null) {
                 // Can't find the transaction - maybe on a different chain?
                 return;
             }

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

@@ -1121,6 +1121,7 @@ public class Synchronizer extends Thread {
 			// If common block is too far behind us then we're on massively different forks so give up.
 			if (!force && testHeight < ourHeight - MAXIMUM_COMMON_DELTA) {
 				LOGGER.info(String.format("Blockchain too divergent with peer %s", peer));
+				peer.setLastTooDivergentTime(NTP.getTime());
 				return SynchronizationResult.TOO_DIVERGENT;
 			}
 
@@ -1130,6 +1131,9 @@ public class Synchronizer extends Thread {
 			testHeight = Math.max(testHeight - step, 1);
 		}
 
+		// Peer not considered too divergent
+		peer.setLastTooDivergentTime(0L);
+
 		// Prepend test block's summary as first block summary, as summaries returned are *after* test block
 		BlockSummaryData testBlockSummary = new BlockSummaryData(testBlockData);
 		blockSummariesFromCommon.add(0, testBlockSummary);

src/main/java/org/qortal/controller/arbitrary/ArbitraryDataCleanupManager.java

@@ -11,10 +11,7 @@ import org.qortal.repository.RepositoryManager;
 import org.qortal.settings.Settings;
 import org.qortal.transaction.Transaction;
 import org.qortal.transaction.Transaction.TransactionType;
-import org.qortal.utils.ArbitraryTransactionUtils;
-import org.qortal.utils.Base58;
-import org.qortal.utils.FilesystemUtils;
-import org.qortal.utils.NTP;
+import org.qortal.utils.*;
 
 import java.io.File;
 import java.io.IOException;
@@ -137,7 +134,7 @@ public class ArbitraryDataCleanupManager extends Thread {
 
 						// Fetch the transaction data
 						ArbitraryTransactionData arbitraryTransactionData = ArbitraryTransactionUtils.fetchTransactionData(repository, signature);
-						if (arbitraryTransactionData == null) {
+						if (arbitraryTransactionData == null || arbitraryTransactionData.getService() == null) {
 							continue;
 						}
 
@@ -204,7 +201,7 @@ public class ArbitraryDataCleanupManager extends Thread {
 
 						if (completeFileExists && !allChunksExist) {
 							// We have the complete file but not the chunks, so let's convert it
-							LOGGER.info(String.format("Transaction %s has complete file but no chunks",
+							LOGGER.debug(String.format("Transaction %s has complete file but no chunks",
 									Base58.encode(arbitraryTransactionData.getSignature())));
 
 							ArbitraryTransactionUtils.convertFileToChunks(arbitraryTransactionData, now, STALE_FILE_TIMEOUT);
@@ -239,7 +236,7 @@ public class ArbitraryDataCleanupManager extends Thread {
 
 					// Delete random data associated with name if we're over our storage limit for this name
 					// Use the DELETION_THRESHOLD, for the same reasons as above
-					for (String followedName : storageManager.followedNames()) {
+					for (String followedName : ListUtils.followedNames()) {
 						if (isStopping) {
 							return;
 						}
@@ -487,7 +484,7 @@ public class ArbitraryDataCleanupManager extends Thread {
 
 				// Delete data relating to blocked names
 				String name = directory.getName();
-				if (name != null && storageManager.isNameBlocked(name)) {
+				if (name != null && ListUtils.isNameBlocked(name)) {
 					this.safeDeleteDirectory(directory, "blocked name");
 				}
 

src/main/java/org/qortal/controller/arbitrary/ArbitraryDataFileListManager.java

@@ -20,6 +20,7 @@ import org.qortal.repository.Repository;
 import org.qortal.repository.RepositoryManager;
 import org.qortal.settings.Settings;
 import org.qortal.utils.Base58;
+import org.qortal.utils.ListUtils;
 import org.qortal.utils.NTP;
 import org.qortal.utils.Triple;
 
@@ -258,8 +259,6 @@ public class ArbitraryDataFileListManager {
     // Lookup file lists by signature (and optionally hashes)
 
     public boolean fetchArbitraryDataFileList(ArbitraryTransactionData arbitraryTransactionData) {
-        byte[] digest = arbitraryTransactionData.getData();
-        byte[] metadataHash = arbitraryTransactionData.getMetadataHash();
         byte[] signature = arbitraryTransactionData.getSignature();
         String signature58 = Base58.encode(signature);
 
@@ -286,8 +285,7 @@ public class ArbitraryDataFileListManager {
 
         // Find hashes that we are missing
         try {
-            ArbitraryDataFile arbitraryDataFile = ArbitraryDataFile.fromHash(digest, signature);
-            arbitraryDataFile.setMetadataHash(metadataHash);
+            ArbitraryDataFile arbitraryDataFile = ArbitraryDataFile.fromTransactionData(arbitraryTransactionData);
             missingHashes = arbitraryDataFile.missingHashes();
         } catch (DataException e) {
             // Leave missingHashes as null, so that all hashes are requested
@@ -460,10 +458,9 @@ public class ArbitraryDataFileListManager {
 
             arbitraryTransactionData = (ArbitraryTransactionData) transactionData;
 
-            // Load data file(s)
-            ArbitraryDataFile arbitraryDataFile = ArbitraryDataFile.fromHash(arbitraryTransactionData.getData(), signature);
-            arbitraryDataFile.setMetadataHash(arbitraryTransactionData.getMetadataHash());
-
+//          // Load data file(s)
+//          ArbitraryDataFile arbitraryDataFile = ArbitraryDataFile.fromTransactionData(arbitraryTransactionData);
+//
 //			// Check all hashes exist
 //			for (byte[] hash : hashes) {
 //				//LOGGER.debug("Received hash {}", Base58.encode(hash));
@@ -507,7 +504,7 @@ public class ArbitraryDataFileListManager {
 
         // Forwarding
         if (isRelayRequest && Settings.getInstance().isRelayModeEnabled()) {
-            boolean isBlocked = (arbitraryTransactionData == null || ArbitraryDataStorageManager.getInstance().isNameBlocked(arbitraryTransactionData.getName()));
+            boolean isBlocked = (arbitraryTransactionData == null || ListUtils.isNameBlocked(arbitraryTransactionData.getName()));
             if (!isBlocked) {
                 Peer requestingPeer = request.getB();
                 if (requestingPeer != null) {
@@ -594,12 +591,8 @@ public class ArbitraryDataFileListManager {
                 // Check if we're even allowed to serve data for this transaction
                 if (ArbitraryDataStorageManager.getInstance().canStoreData(transactionData)) {
 
-                    byte[] hash = transactionData.getData();
-                    byte[] metadataHash = transactionData.getMetadataHash();
-
                     // Load file(s) and add any that exist to the list of hashes
-                    ArbitraryDataFile arbitraryDataFile = ArbitraryDataFile.fromHash(hash, signature);
-                    arbitraryDataFile.setMetadataHash(metadataHash);
+                    ArbitraryDataFile arbitraryDataFile = ArbitraryDataFile.fromTransactionData(transactionData);
 
                     // If the peer didn't supply a hash list, we need to return all hashes for this transaction
                     if (requestedHashes == null || requestedHashes.isEmpty()) {
@@ -690,7 +683,7 @@ public class ArbitraryDataFileListManager {
         }
 
         // We may need to forward this request on
-        boolean isBlocked = (transactionData == null || ArbitraryDataStorageManager.getInstance().isNameBlocked(transactionData.getName()));
+        boolean isBlocked = (transactionData == null || ListUtils.isNameBlocked(transactionData.getName()));
         if (Settings.getInstance().isRelayModeEnabled() && !isBlocked) {
             // In relay mode - so ask our other peers if they have it
 

src/main/java/org/qortal/controller/arbitrary/ArbitraryDataFileManager.java

@@ -82,7 +82,7 @@ public class ArbitraryDataFileManager extends Thread {
 
         try {
             // Use a fixed thread pool to execute the arbitrary data file requests
-            int threadCount = 10;
+            int threadCount = 5;
             ExecutorService arbitraryDataFileRequestExecutor = Executors.newFixedThreadPool(threadCount);
             for (int i = 0; i < threadCount; i++) {
                 arbitraryDataFileRequestExecutor.execute(new ArbitraryDataFileRequestThread());
@@ -132,9 +132,7 @@ public class ArbitraryDataFileManager extends Thread {
                                            List<byte[]> hashes) throws DataException {
 
         // Load data file(s)
-        ArbitraryDataFile arbitraryDataFile = ArbitraryDataFile.fromHash(arbitraryTransactionData.getData(), signature);
-        byte[] metadataHash = arbitraryTransactionData.getMetadataHash();
-        arbitraryDataFile.setMetadataHash(metadataHash);
+        ArbitraryDataFile arbitraryDataFile = ArbitraryDataFile.fromTransactionData(arbitraryTransactionData);
         boolean receivedAtLeastOneFile = false;
 
         // Now fetch actual data from this peer
@@ -148,10 +146,10 @@ public class ArbitraryDataFileManager extends Thread {
                 if (!arbitraryDataFileRequests.containsKey(Base58.encode(hash))) {
                     LOGGER.debug("Requesting data file {} from peer {}", hash58, peer);
                     Long startTime = NTP.getTime();
-                    ArbitraryDataFileMessage receivedArbitraryDataFileMessage = fetchArbitraryDataFile(peer, null, signature, hash, null);
+                    ArbitraryDataFile receivedArbitraryDataFile = fetchArbitraryDataFile(peer, null, signature, hash, null);
                     Long endTime = NTP.getTime();
-                    if (receivedArbitraryDataFileMessage != null && receivedArbitraryDataFileMessage.getArbitraryDataFile() != null) {
-                        LOGGER.debug("Received data file {} from peer {}. Time taken: {} ms", receivedArbitraryDataFileMessage.getArbitraryDataFile().getHash58(), peer, (endTime-startTime));
+                    if (receivedArbitraryDataFile != null) {
+                        LOGGER.debug("Received data file {} from peer {}. Time taken: {} ms", receivedArbitraryDataFile.getHash58(), peer, (endTime-startTime));
                         receivedAtLeastOneFile = true;
 
                         // Remove this hash from arbitraryDataFileHashResponses now that we have received it
@@ -193,11 +191,11 @@ public class ArbitraryDataFileManager extends Thread {
         return receivedAtLeastOneFile;
     }
 
-    private ArbitraryDataFileMessage fetchArbitraryDataFile(Peer peer, Peer requestingPeer, byte[] signature, byte[] hash, Message originalMessage) throws DataException {
+    private ArbitraryDataFile fetchArbitraryDataFile(Peer peer, Peer requestingPeer, byte[] signature, byte[] hash, Message originalMessage) throws DataException {
         ArbitraryDataFile existingFile = ArbitraryDataFile.fromHash(hash, signature);
         boolean fileAlreadyExists = existingFile.exists();
         String hash58 = Base58.encode(hash);
-        ArbitraryDataFileMessage arbitraryDataFileMessage;
+        ArbitraryDataFile arbitraryDataFile;
 
         // Fetch the file if it doesn't exist locally
         if (!fileAlreadyExists) {
@@ -227,28 +225,32 @@ public class ArbitraryDataFileManager extends Thread {
             }
 
             ArbitraryDataFileMessage peersArbitraryDataFileMessage = (ArbitraryDataFileMessage) response;
-            arbitraryDataFileMessage = new ArbitraryDataFileMessage(signature, peersArbitraryDataFileMessage.getArbitraryDataFile());
+            arbitraryDataFile = peersArbitraryDataFileMessage.getArbitraryDataFile();
         } else {
             LOGGER.debug(String.format("File hash %s already exists, so skipping the request", hash58));
-            arbitraryDataFileMessage = new ArbitraryDataFileMessage(signature, existingFile);
+            arbitraryDataFile = existingFile;
+        }
+
+        if (arbitraryDataFile == null) {
+            // We don't have a file, so give up here
+            return null;
         }
 
         // We might want to forward the request to the peer that originally requested it
-        this.handleArbitraryDataFileForwarding(requestingPeer, arbitraryDataFileMessage, originalMessage);
+        this.handleArbitraryDataFileForwarding(requestingPeer, new ArbitraryDataFileMessage(signature, arbitraryDataFile), originalMessage);
 
         boolean isRelayRequest = (requestingPeer != null);
         if (isRelayRequest) {
             if (!fileAlreadyExists) {
                 // File didn't exist locally before the request, and it's a forwarding request, so delete it
                 LOGGER.debug("Deleting file {} because it was needed for forwarding only", Base58.encode(hash));
-                ArbitraryDataFile dataFile = arbitraryDataFileMessage.getArbitraryDataFile();
 
                 // Keep trying to delete the data until it is deleted, or we reach 10 attempts
-                dataFile.delete(10);
+                arbitraryDataFile.delete(10);
             }
         }
 
-        return arbitraryDataFileMessage;
+        return arbitraryDataFile;
     }
 
     private void handleFileListRequests(byte[] signature) {
@@ -288,7 +290,7 @@ public class ArbitraryDataFileManager extends Thread {
         // The ID needs to match that of the original request
         message.setId(originalMessage.getId());
 
-        if (!requestingPeer.sendMessage(message)) {
+        if (!requestingPeer.sendMessageWithTimeout(message, (int) ArbitraryDataManager.ARBITRARY_REQUEST_TIMEOUT)) {
             LOGGER.debug("Failed to forward arbitrary data file to peer {}", requestingPeer);
             requestingPeer.disconnect("failed to forward arbitrary data file");
         }
@@ -564,13 +566,16 @@ public class ArbitraryDataFileManager extends Thread {
                 LOGGER.trace("Hash {} exists", hash58);
 
                 // We can serve the file directly as we already have it
+                LOGGER.debug("Sending file {}...", arbitraryDataFile);
                 ArbitraryDataFileMessage arbitraryDataFileMessage = new ArbitraryDataFileMessage(signature, arbitraryDataFile);
                 arbitraryDataFileMessage.setId(message.getId());
-                if (!peer.sendMessage(arbitraryDataFileMessage)) {
-                    LOGGER.debug("Couldn't sent file");
+                if (!peer.sendMessageWithTimeout(arbitraryDataFileMessage, (int) ArbitraryDataManager.ARBITRARY_REQUEST_TIMEOUT)) {
+                    LOGGER.debug("Couldn't send file {}", arbitraryDataFile);
                     peer.disconnect("failed to send file");
                 }
-                LOGGER.debug("Sent file {}", arbitraryDataFile);
+                else {
+                    LOGGER.debug("Sent file {}", arbitraryDataFile);
+                }
             }
             else if (relayInfo != null) {
                 LOGGER.debug("We have relay info for hash {}", Base58.encode(hash));

src/main/java/org/qortal/controller/arbitrary/ArbitraryDataFileRequestThread.java

@@ -114,7 +114,7 @@ public class ArbitraryDataFileRequestThread implements Runnable {
                 return;
             }
 
-            LOGGER.debug("Fetching file {} from peer {} via request thread...", hash58, peer);
+            LOGGER.trace("Fetching file {} from peer {} via request thread...", hash58, peer);
             arbitraryDataFileManager.fetchArbitraryDataFiles(repository, peer, signature, arbitraryTransactionData, Arrays.asList(hash));
 
         } catch (DataException e) {

src/main/java/org/qortal/controller/arbitrary/ArbitraryDataManager.java

@@ -27,6 +27,7 @@ import org.qortal.transaction.ArbitraryTransaction;
 import org.qortal.transaction.Transaction.TransactionType;
 import org.qortal.utils.ArbitraryTransactionUtils;
 import org.qortal.utils.Base58;
+import org.qortal.utils.ListUtils;
 import org.qortal.utils.NTP;
 
 public class ArbitraryDataManager extends Thread {
@@ -172,7 +173,7 @@ public class ArbitraryDataManager extends Thread {
 
 	private void processNames() throws InterruptedException {
 		// Fetch latest list of followed names
-		List<String> followedNames = ResourceListManager.getInstance().getStringsInList("followedNames");
+		List<String> followedNames = ListUtils.followedNames();
 		if (followedNames == null || followedNames.isEmpty()) {
 			return;
 		}
@@ -398,6 +399,11 @@ public class ArbitraryDataManager extends Thread {
 	// Entrypoint to request new metadata from peers
 	public ArbitraryDataTransactionMetadata fetchMetadata(ArbitraryTransactionData arbitraryTransactionData) {
 
+		if (arbitraryTransactionData.getService() == null) {
+			// Can't fetch metadata without a valid service
+			return null;
+		}
+
 		ArbitraryDataResource resource = new ArbitraryDataResource(
 				arbitraryTransactionData.getName(),
 				ArbitraryDataFile.ResourceIdType.NAME,
@@ -489,7 +495,7 @@ public class ArbitraryDataManager extends Thread {
 	public void invalidateCache(ArbitraryTransactionData arbitraryTransactionData) {
 		String signature58 = Base58.encode(arbitraryTransactionData.getSignature());
 
-		if (arbitraryTransactionData.getName() != null) {
+		if (arbitraryTransactionData.getName() != null && arbitraryTransactionData.getService() != null) {
 			String resourceId = arbitraryTransactionData.getName().toLowerCase();
 			Service service = arbitraryTransactionData.getService();
 			String identifier = arbitraryTransactionData.getIdentifier();

src/main/java/org/qortal/controller/arbitrary/ArbitraryDataStorageManager.java

@@ -5,15 +5,11 @@ import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.qortal.data.transaction.ArbitraryTransactionData;
 import org.qortal.data.transaction.TransactionData;
-import org.qortal.list.ResourceListManager;
 import org.qortal.repository.DataException;
 import org.qortal.repository.Repository;
 import org.qortal.settings.Settings;
 import org.qortal.transaction.Transaction;
-import org.qortal.utils.ArbitraryTransactionUtils;
-import org.qortal.utils.Base58;
-import org.qortal.utils.FilesystemUtils;
-import org.qortal.utils.NTP;
+import org.qortal.utils.*;
 
 import java.io.IOException;
 import java.io.UncheckedIOException;
@@ -48,7 +44,6 @@ public class ArbitraryDataStorageManager extends Thread {
     private List<ArbitraryTransactionData> hostedTransactions;
 
     private String searchQuery;
-    private List<ArbitraryTransactionData> searchResultsTransactions;
 
     private static final long DIRECTORY_SIZE_CHECK_INTERVAL = 10 * 60 * 1000L; // 10 minutes
 
@@ -136,11 +131,11 @@ public class ArbitraryDataStorageManager extends Thread {
             case ALL:
             case VIEWED:
                 // If the policy includes viewed data, we can host it as long as it's not blocked
-                return !this.isNameBlocked(name);
+                return !ListUtils.isNameBlocked(name);
 
             case FOLLOWED:
                 // If the policy is for followed data only, we have to be following it
-                return this.isFollowingName(name);
+                return ListUtils.isFollowingName(name);
 
                 // For NONE or all else, we shouldn't host this data
             case NONE:
@@ -189,14 +184,14 @@ public class ArbitraryDataStorageManager extends Thread {
         }
 
         // Never fetch data from blocked names, even if they are followed
-        if (this.isNameBlocked(name)) {
+        if (ListUtils.isNameBlocked(name)) {
             return false;
         }
 
         switch (Settings.getInstance().getStoragePolicy()) {
             case FOLLOWED:
             case FOLLOWED_OR_VIEWED:
-                return this.isFollowingName(name);
+                return ListUtils.isFollowingName(name);
                 
             case ALL:
                 return true;
@@ -236,7 +231,7 @@ public class ArbitraryDataStorageManager extends Thread {
      * @return boolean - whether the resource is blocked or not
      */
     public boolean isBlocked(ArbitraryTransactionData arbitraryTransactionData) {
-        return isNameBlocked(arbitraryTransactionData.getName());
+        return ListUtils.isNameBlocked(arbitraryTransactionData.getName());
     }
 
     private boolean isDataTypeAllowed(ArbitraryTransactionData arbitraryTransactionData) {
@@ -254,22 +249,6 @@ public class ArbitraryDataStorageManager extends Thread {
         return true;
     }
 
-    public boolean isNameBlocked(String name) {
-        return ResourceListManager.getInstance().listContains("blockedNames", name, false);
-    }
-
-    private boolean isFollowingName(String name) {
-        return ResourceListManager.getInstance().listContains("followedNames", name, false);
-    }
-
-    public List<String> followedNames() {
-        return ResourceListManager.getInstance().getStringsInList("followedNames");
-    }
-
-    private int followedNamesCount() {
-        return ResourceListManager.getInstance().getItemCountForList("followedNames");
-    }
-
 
     public List<ArbitraryTransactionData> loadAllHostedTransactions(Repository repository) {
         
@@ -344,11 +323,6 @@ public class ArbitraryDataStorageManager extends Thread {
      */
 
     public List<ArbitraryTransactionData> searchHostedTransactions(Repository repository, String query, Integer limit, Integer offset) {
-        // Load from results cache if we can (results that exists for the same query), to avoid disk reads
-        if (this.searchResultsTransactions != null && this.searchQuery.equals(query.toLowerCase())) {
-            return ArbitraryTransactionUtils.limitOffsetTransactions(this.searchResultsTransactions, limit, offset);
-        }
-
         // Using cache if we can, to avoid disk reads
         if (this.hostedTransactions == null) {
             this.hostedTransactions = this.loadAllHostedTransactions(repository);
@@ -376,10 +350,7 @@ public class ArbitraryDataStorageManager extends Thread {
         // Sort by newest first
         searchResultsList.sort(Comparator.comparingLong(ArbitraryTransactionData::getTimestamp).reversed());
 
-        // Update cache
-        this.searchResultsTransactions = searchResultsList;
-
-        return ArbitraryTransactionUtils.limitOffsetTransactions(this.searchResultsTransactions, limit, offset);
+        return ArbitraryTransactionUtils.limitOffsetTransactions(searchResultsList, limit, offset);
     }
 
     /**
@@ -522,7 +493,7 @@ public class ArbitraryDataStorageManager extends Thread {
             return true;
         }
 
-        int followedNamesCount = this.followedNamesCount();
+        int followedNamesCount = ListUtils.followedNamesCount();
         if (followedNamesCount == 0) {
             // Not following any names, so we have space
             return true;
@@ -552,7 +523,7 @@ public class ArbitraryDataStorageManager extends Thread {
     }
 
     public long storageCapacityPerName(double threshold) {
-        int followedNamesCount = this.followedNamesCount();
+        int followedNamesCount = ListUtils.followedNamesCount();
         if (followedNamesCount == 0) {
             // Not following any names, so we have the total space available
             return this.getStorageCapacityIncludingThreshold(threshold);

src/main/java/org/qortal/controller/arbitrary/ArbitraryMetadataManager.java

@@ -16,6 +16,7 @@ import org.qortal.repository.Repository;
 import org.qortal.repository.RepositoryManager;
 import org.qortal.settings.Settings;
 import org.qortal.utils.Base58;
+import org.qortal.utils.ListUtils;
 import org.qortal.utils.NTP;
 import org.qortal.utils.Triple;
 
@@ -332,7 +333,7 @@ public class ArbitraryMetadataManager {
             }
 
             // Check if the name is blocked
-            boolean isBlocked = (arbitraryTransactionData == null || ArbitraryDataStorageManager.getInstance().isNameBlocked(arbitraryTransactionData.getName()));
+            boolean isBlocked = (arbitraryTransactionData == null || ListUtils.isNameBlocked(arbitraryTransactionData.getName()));
             if (!isBlocked) {
                 Peer requestingPeer = request.getB();
                 if (requestingPeer != null) {
@@ -420,7 +421,7 @@ public class ArbitraryMetadataManager {
         }
 
         // We may need to forward this request on
-        boolean isBlocked = (transactionData == null || ArbitraryDataStorageManager.getInstance().isNameBlocked(transactionData.getName()));
+        boolean isBlocked = (transactionData == null || ListUtils.isNameBlocked(transactionData.getName()));
         if (Settings.getInstance().isRelayModeEnabled() && !isBlocked) {
             // In relay mode - so ask our other peers if they have it
 

src/main/java/org/qortal/controller/repository/AtStatesPruner.java

@@ -39,9 +39,11 @@ public class AtStatesPruner implements Runnable {
 
 		try (final Repository repository = RepositoryManager.getRepository()) {
 			int pruneStartHeight = repository.getATRepository().getAtPruneHeight();
+			int maxLatestAtStatesHeight = PruneManager.getMaxHeightForLatestAtStates(repository);
 
 			repository.discardChanges();
-			repository.getATRepository().rebuildLatestAtStates();
+			repository.getATRepository().rebuildLatestAtStates(maxLatestAtStatesHeight);
+			repository.saveChanges();
 
 			while (!Controller.isStopping()) {
 				repository.discardChanges();
@@ -91,7 +93,8 @@ public class AtStatesPruner implements Runnable {
 					if (upperPrunableHeight > upperBatchHeight) {
 						pruneStartHeight = upperBatchHeight;
 						repository.getATRepository().setAtPruneHeight(pruneStartHeight);
-						repository.getATRepository().rebuildLatestAtStates();
+						maxLatestAtStatesHeight = PruneManager.getMaxHeightForLatestAtStates(repository);
+						repository.getATRepository().rebuildLatestAtStates(maxLatestAtStatesHeight);
 						repository.saveChanges();
 
 						final int finalPruneStartHeight = pruneStartHeight;

src/main/java/org/qortal/controller/repository/AtStatesTrimmer.java

@@ -26,9 +26,11 @@ public class AtStatesTrimmer implements Runnable {
 
 		try (final Repository repository = RepositoryManager.getRepository()) {
 			int trimStartHeight = repository.getATRepository().getAtTrimHeight();
+			int maxLatestAtStatesHeight = PruneManager.getMaxHeightForLatestAtStates(repository);
 
 			repository.discardChanges();
-			repository.getATRepository().rebuildLatestAtStates();
+			repository.getATRepository().rebuildLatestAtStates(maxLatestAtStatesHeight);
+			repository.saveChanges();
 
 			while (!Controller.isStopping()) {
 				repository.discardChanges();
@@ -69,7 +71,8 @@ public class AtStatesTrimmer implements Runnable {
 					if (upperTrimmableHeight > upperBatchHeight) {
 						trimStartHeight = upperBatchHeight;
 						repository.getATRepository().setAtTrimHeight(trimStartHeight);
-						repository.getATRepository().rebuildLatestAtStates();
+						maxLatestAtStatesHeight = PruneManager.getMaxHeightForLatestAtStates(repository);
+						repository.getATRepository().rebuildLatestAtStates(maxLatestAtStatesHeight);
 						repository.saveChanges();
 
 						final int finalTrimStartHeight = trimStartHeight;

src/main/java/org/qortal/controller/repository/BlockArchiveRebuilder.java

@@ -0,0 +1,121 @@
+package org.qortal.controller.repository;
+
+import org.apache.commons.io.FileUtils;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.qortal.controller.Controller;
+import org.qortal.controller.Synchronizer;
+import org.qortal.repository.*;
+import org.qortal.settings.Settings;
+import org.qortal.transform.TransformationException;
+
+import java.io.IOException;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+
+
+public class BlockArchiveRebuilder {
+
+    private static final Logger LOGGER = LogManager.getLogger(BlockArchiveRebuilder.class);
+
+    private final int serializationVersion;
+
+    public BlockArchiveRebuilder(int serializationVersion) {
+        this.serializationVersion = serializationVersion;
+    }
+
+    public void start() throws DataException, IOException {
+        if (!Settings.getInstance().isArchiveEnabled() || Settings.getInstance().isLite()) {
+            return;
+        }
+
+        // New archive path is in a different location from original archive path, to avoid conflicts.
+        // It will be moved later, once the process is complete.
+        final Path newArchivePath = Paths.get(Settings.getInstance().getRepositoryPath(), "archive-rebuild");
+        final Path originalArchivePath = Paths.get(Settings.getInstance().getRepositoryPath(), "archive");
+
+        // Delete archive-rebuild if it exists from a previous attempt
+        FileUtils.deleteDirectory(newArchivePath.toFile());
+
+        try (final Repository repository = RepositoryManager.getRepository()) {
+            int startHeight = 1; // We need to rebuild the entire archive
+
+            LOGGER.info("Rebuilding block archive from height {}...", startHeight);
+
+            while (!Controller.isStopping()) {
+                repository.discardChanges();
+
+                Thread.sleep(1000L);
+
+                // Don't even attempt if we're mid-sync as our repository requests will be delayed for ages
+                if (Synchronizer.getInstance().isSynchronizing()) {
+                    continue;
+                }
+
+                // Rebuild archive
+                try {
+                    final int maximumArchiveHeight = BlockArchiveReader.getInstance().getHeightOfLastArchivedBlock();
+                    if (startHeight >= maximumArchiveHeight) {
+                        // We've finished.
+                        // Delete existing archive and move the newly built one into its place
+                        FileUtils.deleteDirectory(originalArchivePath.toFile());
+                        FileUtils.moveDirectory(newArchivePath.toFile(), originalArchivePath.toFile());
+                        BlockArchiveReader.getInstance().invalidateFileListCache();
+                        LOGGER.info("Block archive successfully rebuilt");
+                        return;
+                    }
+
+                    BlockArchiveWriter writer = new BlockArchiveWriter(startHeight, maximumArchiveHeight, serializationVersion, newArchivePath, repository);
+
+                    // Set data source to BLOCK_ARCHIVE as we are rebuilding
+                    writer.setDataSource(BlockArchiveWriter.BlockArchiveDataSource.BLOCK_ARCHIVE);
+
+                    // We can't enforce the 100MB file size target, as the final file needs to contain all blocks
+                    // that exist in the current archive. Otherwise, the final blocks in the archive will be lost.
+                    writer.setShouldEnforceFileSizeTarget(false);
+
+                    // We want to log the rebuild progress
+                    writer.setShouldLogProgress(true);
+
+                    BlockArchiveWriter.BlockArchiveWriteResult result = writer.write();
+                    switch (result) {
+                        case OK:
+                            // Increment block archive height
+                            startHeight += writer.getWrittenCount();
+                            repository.saveChanges();
+                            break;
+
+                        case STOPPING:
+                            return;
+
+                        // We've reached the limit of the blocks we can archive
+                        // Sleep for a while to allow more to become available
+                        case NOT_ENOUGH_BLOCKS:
+                            // This shouldn't happen, as we're not enforcing minimum file sizes
+                            repository.discardChanges();
+                            throw new DataException("Unable to rebuild archive due to unexpected NOT_ENOUGH_BLOCKS response.");
+
+                        case BLOCK_NOT_FOUND:
+                            // We tried to archive a block that didn't exist. This is a major failure and likely means
+                            // that a bootstrap or re-sync is needed. Try again every minute until then.
+                            LOGGER.info("Error: block not found when rebuilding archive. If this error persists, " +
+                                    "a bootstrap or re-sync may be needed.");
+                            repository.discardChanges();
+                            throw new DataException("Unable to rebuild archive because a block is missing.");
+                    }
+
+                } catch (IOException | TransformationException e) {
+                    LOGGER.info("Caught exception when rebuilding block archive", e);
+                    throw new DataException("Unable to rebuild block archive");
+                }
+
+            }
+        } catch (InterruptedException e) {
+            // Do nothing
+        } finally {
+            // Delete archive-rebuild if it still exists, as that means something went wrong
+            FileUtils.deleteDirectory(newArchivePath.toFile());
+        }
+    }
+
+}

src/main/java/org/qortal/controller/repository/NamesDatabaseIntegrityCheck.java

@@ -13,7 +13,9 @@ import org.qortal.repository.RepositoryManager;
 import org.qortal.transaction.Transaction.TransactionType;
 import org.qortal.utils.Unicode;
 
+import java.math.BigInteger;
 import java.util.*;
+import java.util.stream.Collectors;
 
 public class NamesDatabaseIntegrityCheck {
 
@@ -28,16 +30,8 @@ public class NamesDatabaseIntegrityCheck {
 
     private List<TransactionData> nameTransactions = new ArrayList<>();
 
+
     public int rebuildName(String name, Repository repository) {
-        return this.rebuildName(name, repository, null);
-    }
-
-    public int rebuildName(String name, Repository repository, List<String> referenceNames) {
-        // "referenceNames" tracks the linked names that have already been rebuilt, to prevent circular dependencies
-        if (referenceNames == null) {
-            referenceNames = new ArrayList<>();
-        }
-
         int modificationCount = 0;
         try {
             List<TransactionData> transactions = this.fetchAllTransactionsInvolvingName(name, repository);
@@ -46,6 +40,14 @@ public class NamesDatabaseIntegrityCheck {
                 return modificationCount;
             }
 
+            // If this name has been updated at any point, we need to add transactions from the other names to the sequence
+            int added = this.addAdditionalTransactionsRelatingToName(transactions, name, repository);
+            while (added > 0) {
+                // Keep going until all have been added
+                LOGGER.trace("{} added for {}. Looking for more transactions...", added, name);
+                added = this.addAdditionalTransactionsRelatingToName(transactions, name, repository);
+            }
+
             // Loop through each past transaction and re-apply it to the Names table
             for (TransactionData currentTransaction : transactions) {
 
@@ -61,29 +63,14 @@ public class NamesDatabaseIntegrityCheck {
                 // Process UPDATE_NAME transactions
                 if (currentTransaction.getType() == TransactionType.UPDATE_NAME) {
                     UpdateNameTransactionData updateNameTransactionData = (UpdateNameTransactionData) currentTransaction;
-
-                    if (Objects.equals(updateNameTransactionData.getNewName(), name) &&
-                            !Objects.equals(updateNameTransactionData.getName(), updateNameTransactionData.getNewName())) {
-                        // This renames an existing name, so we need to process that instead
-
-                        if (!referenceNames.contains(name)) {
-                            referenceNames.add(name);
-                            this.rebuildName(updateNameTransactionData.getName(), repository, referenceNames);
-                        }
-                        else {
-                            // We've already processed this name so there's nothing more to do
-                        }
-                    }
-                    else {
-                        Name nameObj = new Name(repository, name);
-                        if (nameObj != null && nameObj.getNameData() != null) {
-                            nameObj.update(updateNameTransactionData);
-                            modificationCount++;
-                            LOGGER.trace("Processed UPDATE_NAME transaction for name {}", name);
-                        } else {
-                            // Something went wrong
-                            throw new DataException(String.format("Name data not found for name %s", updateNameTransactionData.getName()));
-                        }
+                    Name nameObj = new Name(repository, updateNameTransactionData.getName());
+                    if (nameObj != null && nameObj.getNameData() != null) {
+                        nameObj.update(updateNameTransactionData);
+                        modificationCount++;
+                        LOGGER.trace("Processed UPDATE_NAME transaction for name {}", name);
+                    } else {
+                        // Something went wrong
+                        throw new DataException(String.format("Name data not found for name %s", updateNameTransactionData.getName()));
                     }
                 }
 
@@ -102,6 +89,21 @@ public class NamesDatabaseIntegrityCheck {
                     }
                 }
 
+                // Process CANCEL_SELL_NAME transactions
+                if (currentTransaction.getType() == TransactionType.CANCEL_SELL_NAME) {
+                    CancelSellNameTransactionData cancelSellNameTransactionData = (CancelSellNameTransactionData) currentTransaction;
+                    Name nameObj = new Name(repository, cancelSellNameTransactionData.getName());
+                    if (nameObj != null && nameObj.getNameData() != null) {
+                        nameObj.cancelSell(cancelSellNameTransactionData);
+                        modificationCount++;
+                        LOGGER.trace("Processed CANCEL_SELL_NAME transaction for name {}", name);
+                    }
+                    else {
+                        // Something went wrong
+                        throw new DataException(String.format("Name data not found for name %s", cancelSellNameTransactionData.getName()));
+                    }
+                }
+
                 // Process BUY_NAME transactions
                 if (currentTransaction.getType() == TransactionType.BUY_NAME) {
                     BuyNameTransactionData buyNameTransactionData = (BuyNameTransactionData) currentTransaction;
@@ -128,7 +130,7 @@ public class NamesDatabaseIntegrityCheck {
     public int rebuildAllNames() {
         int modificationCount = 0;
         try (final Repository repository = RepositoryManager.getRepository()) {
-            List<String> names = this.fetchAllNames(repository);
+            List<String> names = this.fetchAllNames(repository); // TODO: de-duplicate, to speed up this process
             for (String name : names) {
                 modificationCount += this.rebuildName(name, repository);
             }
@@ -326,6 +328,10 @@ public class NamesDatabaseIntegrityCheck {
                 TransactionType.BUY_NAME, Arrays.asList("name = ?"), Arrays.asList(name));
         signatures.addAll(buyNameTransactions);
 
+        List<byte[]> cancelSellNameTransactions = repository.getTransactionRepository().getSignaturesMatchingCustomCriteria(
+                TransactionType.CANCEL_SELL_NAME, Arrays.asList("name = ?"), Arrays.asList(name));
+        signatures.addAll(cancelSellNameTransactions);
+
         List<TransactionData> transactions = new ArrayList<>();
         for (byte[] signature : signatures) {
             TransactionData transactionData = repository.getTransactionRepository().fromSignature(signature);
@@ -335,8 +341,8 @@ public class NamesDatabaseIntegrityCheck {
             }
         }
 
-        // Sort by lowest timestamp first
-        transactions.sort(Comparator.comparingLong(TransactionData::getTimestamp));
+        // Sort by lowest block height first
+        sortTransactions(transactions);
 
         return transactions;
     }
@@ -390,8 +396,77 @@ public class NamesDatabaseIntegrityCheck {
                     names.add(sellNameTransactionData.getName());
                 }
             }
+            if ((transactionData instanceof CancelSellNameTransactionData)) {
+                CancelSellNameTransactionData cancelSellNameTransactionData = (CancelSellNameTransactionData) transactionData;
+                if (!names.contains(cancelSellNameTransactionData.getName())) {
+                    names.add(cancelSellNameTransactionData.getName());
+                }
+            }
         }
         return names;
     }
 
+    private int addAdditionalTransactionsRelatingToName(List<TransactionData> transactions, String name, Repository repository) throws DataException {
+        int added = 0;
+
+        // If this name has been updated at any point, we need to add transactions from the other names to the sequence
+        List<String> otherNames = new ArrayList<>();
+        List<TransactionData> updateNameTransactions = transactions.stream().filter(t -> t.getType() == TransactionType.UPDATE_NAME).collect(Collectors.toList());
+        for (TransactionData transactionData : updateNameTransactions) {
+            UpdateNameTransactionData updateNameTransactionData = (UpdateNameTransactionData) transactionData;
+            // If the newName field isn't empty, and either the "name" or "newName" is different from our reference name,
+            // we should remember this additional name, in case it has relevant transactions associated with it.
+            if (updateNameTransactionData.getNewName() != null && !updateNameTransactionData.getNewName().isEmpty()) {
+                if (!Objects.equals(updateNameTransactionData.getName(), name)) {
+                    otherNames.add(updateNameTransactionData.getName());
+                }
+                if (!Objects.equals(updateNameTransactionData.getNewName(), name)) {
+                    otherNames.add(updateNameTransactionData.getNewName());
+                }
+            }
+        }
+
+
+        for (String otherName : otherNames) {
+            List<TransactionData> otherNameTransactions = this.fetchAllTransactionsInvolvingName(otherName, repository);
+            for (TransactionData otherNameTransactionData : otherNameTransactions) {
+                if (!transactions.contains(otherNameTransactionData)) {
+                    // Add new transaction relating to other name
+                    transactions.add(otherNameTransactionData);
+                    added++;
+                }
+            }
+        }
+
+        if (added > 0) {
+            // New transaction(s) added, so re-sort
+            sortTransactions(transactions);
+        }
+
+        return added;
+    }
+
+    private void sortTransactions(List<TransactionData> transactions) {
+        Collections.sort(transactions, new Comparator() {
+            public int compare(Object o1, Object o2) {
+                TransactionData td1 = (TransactionData) o1;
+                TransactionData td2 = (TransactionData) o2;
+
+                // Sort by block height first
+                int heightComparison = td1.getBlockHeight().compareTo(td2.getBlockHeight());
+                if (heightComparison != 0) {
+                    return heightComparison;
+                }
+
+                // Same height so compare timestamps
+                int timestampComparison = Long.compare(td1.getTimestamp(), td2.getTimestamp());
+                if (timestampComparison != 0) {
+                    return timestampComparison;
+                }
+
+                // Same timestamp so compare signatures
+                return new BigInteger(td1.getSignature()).compareTo(new BigInteger(td2.getSignature()));
+            }});
+    }
+
 }

src/main/java/org/qortal/controller/repository/PruneManager.java

@@ -157,4 +157,18 @@ public class PruneManager {
         return (height < latestUnprunedHeight);
     }
 
+    /**
+     * When rebuilding the latest AT states, we need to specify a maxHeight, so that we aren't tracking
+     * very recent AT states that could potentially be orphaned. This method ensures that AT states
+     * are given a sufficient number of blocks to confirm before being tracked as a latest AT state.
+     */
+    public static int getMaxHeightForLatestAtStates(Repository repository) throws DataException {
+        // Get current chain height, and subtract a certain number of "confirmation" blocks
+        // This is to ensure we are basing our latest AT states data on confirmed blocks -
+        // ones that won't be orphaned in any normal circumstances
+        final int confirmationBlocks = 250;
+        final int chainHeight = repository.getBlockRepository().getBlockchainHeight();
+        return chainHeight - confirmationBlocks;
+    }
+
 }

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

@@ -49,6 +49,7 @@ public class Bitcoin extends Bitcoiny {
 						//CLOSED new Server("bitcoin.grey.pw", Server.ConnectionType.SSL, 50002),
 						//CLOSED new Server("btc.litepay.ch", Server.ConnectionType.SSL, 50002),
 						//CLOSED new Server("electrum.pabu.io", Server.ConnectionType.SSL, 50002),
+						//CLOSED new Server("electrumx.dev", Server.ConnectionType.SSL, 50002),
 						//CLOSED new Server("electrumx.hodlwallet.com", Server.ConnectionType.SSL, 50002),
 						//CLOSED new Server("gd42.org", Server.ConnectionType.SSL, 50002),
 						//CLOSED new Server("korea.electrum-server.com", Server.ConnectionType.SSL, 50002),
@@ -56,28 +57,75 @@ public class Bitcoin extends Bitcoiny {
 						//1.15.0 new Server("alviss.coinjoined.com", Server.ConnectionType.SSL, 50002),
 						//1.15.0 new Server("electrum.acinq.co", Server.ConnectionType.SSL, 50002),
 						//1.14.0 new Server("electrum.coinext.com.br", Server.ConnectionType.SSL, 50002),
+						//F1.7.0 new Server("btc.lastingcoin.net", Server.ConnectionType.SSL, 50002),
 						new Server("104.248.139.211", Server.ConnectionType.SSL, 50002),
+						new Server("128.0.190.26", Server.ConnectionType.SSL, 50002),
 						new Server("142.93.6.38", Server.ConnectionType.SSL, 50002),
 						new Server("157.245.172.236", Server.ConnectionType.SSL, 50002),
 						new Server("167.172.226.175", Server.ConnectionType.SSL, 50002),
 						new Server("167.172.42.31", Server.ConnectionType.SSL, 50002),
 						new Server("178.62.80.20", Server.ConnectionType.SSL, 50002),
 						new Server("185.64.116.15", Server.ConnectionType.SSL, 50002),
+						new Server("188.165.206.215", Server.ConnectionType.SSL, 50002),
+						new Server("188.165.211.112", Server.ConnectionType.SSL, 50002),
+						new Server("2azzarita.hopto.org", Server.ConnectionType.SSL, 50002),
+						new Server("2electrumx.hopto.me", Server.ConnectionType.SSL, 56022),
+						new Server("2ex.digitaleveryware.com", Server.ConnectionType.SSL, 50002),
+						new Server("65.39.140.37", Server.ConnectionType.SSL, 50002),
 						new Server("68.183.188.105", Server.ConnectionType.SSL, 50002),
+						new Server("71.73.14.254", Server.ConnectionType.SSL, 50002),
+						new Server("94.23.247.135", Server.ConnectionType.SSL, 50002),
+						new Server("assuredly.not.fyi", Server.ConnectionType.SSL, 50002),
+						new Server("ax101.blockeng.ch", Server.ConnectionType.SSL, 50002),
+						new Server("ax102.blockeng.ch", Server.ConnectionType.SSL, 50002),
+						new Server("b.1209k.com", Server.ConnectionType.SSL, 50002),
+						new Server("b6.1209k.com", Server.ConnectionType.SSL, 50002),
+						new Server("bitcoin.dermichi.com", Server.ConnectionType.SSL, 50002),
+						new Server("bitcoin.lu.ke", Server.ConnectionType.SSL, 50002),
 						new Server("bitcoin.lukechilds.co", Server.ConnectionType.SSL, 50002),
 						new Server("blkhub.net", Server.ConnectionType.SSL, 50002),
-						new Server("btc.lastingcoin.net", Server.ConnectionType.SSL, 50002),
+						new Server("btc.electroncash.dk", Server.ConnectionType.SSL, 60002),
+						new Server("btc.ocf.sh", Server.ConnectionType.SSL, 50002),
 						new Server("btce.iiiiiii.biz", Server.ConnectionType.SSL, 50002),
 						new Server("caleb.vegas", Server.ConnectionType.SSL, 50002),
 						new Server("eai.coincited.net", Server.ConnectionType.SSL, 50002),
+						new Server("electrum.bhoovd.com", Server.ConnectionType.SSL, 50002),
 						new Server("electrum.bitaroo.net", Server.ConnectionType.SSL, 50002),
-						new Server("electrumx.dev", Server.ConnectionType.SSL, 50002),
+						new Server("electrum.bitcoinlizard.net", Server.ConnectionType.SSL, 50002),
+						new Server("electrum.blockstream.info", Server.ConnectionType.SSL, 50002),
+						new Server("electrum.emzy.de", Server.ConnectionType.SSL, 50002),
+						new Server("electrum.exan.tech", Server.ConnectionType.SSL, 50002),
+						new Server("electrum.kendigisland.xyz", Server.ConnectionType.SSL, 50002),
+						new Server("electrum.mmitech.info", Server.ConnectionType.SSL, 50002),
+						new Server("electrum.petrkr.net", Server.ConnectionType.SSL, 50002),
+						new Server("electrum.stippy.com", Server.ConnectionType.SSL, 50002),
+						new Server("electrum.thomasfischbach.de", Server.ConnectionType.SSL, 50002),
+						new Server("electrum0.snel.it", Server.ConnectionType.SSL, 50002),
+						new Server("electrum1.cipig.net", Server.ConnectionType.SSL, 50002),
+						new Server("electrum2.cipig.net", Server.ConnectionType.SSL, 50002),
+						new Server("electrum3.cipig.net", Server.ConnectionType.SSL, 50002),
+						new Server("electrumx.alexridevski.net", Server.ConnectionType.SSL, 50002),
+						new Server("electrumx-core.1209k.com", Server.ConnectionType.SSL, 50002),
 						new Server("elx.bitske.com", Server.ConnectionType.SSL, 50002),
+						new Server("ex03.axalgo.com", Server.ConnectionType.SSL, 50002),
+						new Server("ex05.axalgo.com", Server.ConnectionType.SSL, 50002),
+						new Server("ex07.axalgo.com", Server.ConnectionType.SSL, 50002),
 						new Server("fortress.qtornado.com", Server.ConnectionType.SSL, 50002),
+						new Server("fulcrum.grey.pw", Server.ConnectionType.SSL, 50002),
+						new Server("fulcrum.sethforprivacy.com", Server.ConnectionType.SSL, 51002),
 						new Server("guichet.centure.cc", Server.ConnectionType.SSL, 50002),
-						new Server("kareoke.qoppa.org", Server.ConnectionType.SSL, 50002),
 						new Server("hodlers.beer", Server.ConnectionType.SSL, 50002),
+						new Server("kareoke.qoppa.org", Server.ConnectionType.SSL, 50002),
+						new Server("kirsche.emzy.de", Server.ConnectionType.SSL, 50002),
 						new Server("node1.btccuracao.com", Server.ConnectionType.SSL, 50002),
+						new Server("osr1ex1.compumundohipermegared.one", Server.ConnectionType.SSL, 50002),
+						new Server("smmalis37.ddns.net", Server.ConnectionType.SSL, 50002),
+						new Server("ulrichard.ch", Server.ConnectionType.SSL, 50002),
+						new Server("vmd104012.contaboserver.net", Server.ConnectionType.SSL, 50002),
+						new Server("vmd104014.contaboserver.net", Server.ConnectionType.SSL, 50002),
+						new Server("vmd63185.contaboserver.net", Server.ConnectionType.SSL, 50002),
+						new Server("vmd71287.contaboserver.net", Server.ConnectionType.SSL, 50002),
+						new Server("vmd84592.contaboserver.net", Server.ConnectionType.SSL, 50002),
 						new Server("xtrum.com", Server.ConnectionType.SSL, 50002));
 			}
 

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

@@ -167,6 +167,16 @@ public abstract class Bitcoiny implements ForeignBlockchain {
 		return blockTimestamps.get(5);
 	}
 
+	/**
+	 * Returns height from latest block.
+	 * <p>
+	 * @throws ForeignBlockchainException if error occurs
+	 */
+	public int getBlockchainHeight() throws ForeignBlockchainException {
+		int height = this.blockchainProvider.getCurrentHeight();
+		return height;
+	}
+
 	/** Returns fee per transaction KB. To be overridden for testnet/regtest. */
 	public Coin getFeePerKb() {
 		return this.bitcoinjContext.getFeePerKb();
@@ -357,19 +367,33 @@ public abstract class Bitcoiny implements ForeignBlockchain {
 	 * @return unspent BTC balance, or null if unable to determine balance
 	 */
 	public Long getWalletBalance(String key58) throws ForeignBlockchainException {
-		// It's more accurate to calculate the balance from the transactions, rather than asking Bitcoinj
-		return this.getWalletBalanceFromTransactions(key58);
+		Long balance = 0L;
 
-//		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;
+		List<TransactionOutput> allUnspentOutputs = new ArrayList<>();
+		Set<String> walletAddresses = this.getWalletAddresses(key58);
+		for (String address : walletAddresses) {
+			allUnspentOutputs.addAll(this.getUnspentOutputs(address));
+		}
+		for (TransactionOutput output : allUnspentOutputs) {
+			if (!output.isAvailableForSpending()) {
+				continue;
+			}
+			balance += output.getValue().value;
+		}
+		return balance;
+	}
+
+	public Long getWalletBalanceFromBitcoinj(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 Long getWalletBalanceFromTransactions(String key58) throws ForeignBlockchainException {
@@ -464,6 +488,64 @@ public abstract class Bitcoiny implements ForeignBlockchain {
 		}
 	}
 
+	public Set<String> getWalletAddresses(String key58) throws ForeignBlockchainException {
+		synchronized (this) {
+			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<String> keySet = new HashSet<>();
+
+			int unusedCounter = 0;
+			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);
+					keySet.add(address.toString());
+					byte[] script = ScriptBuilder.createOutputScript(address).getProgram();
+
+					// Ask for transaction history - if it's empty then key has never been used
+					List<TransactionHash> historicTransactionHashes = this.getAddressTransactions(script, false);
+
+					if (!historicTransactionHashes.isEmpty()) {
+						areAllKeysUnused = false;
+					}
+				}
+
+				if (areAllKeysUnused) {
+					// No transactions
+					if (unusedCounter >= Settings.getInstance().getGapLimit()) {
+						// ... and we've hit our search limit
+						break;
+					}
+					// We haven't hit our search limit yet so increment the counter and keep looking
+					unusedCounter += WALLET_KEY_LOOKAHEAD_INCREMENT;
+				} else {
+					// Some keys in this batch were used, so reset the counter
+					unusedCounter = 0;
+				}
+
+				// Generate some more keys
+				keys.addAll(generateMoreKeys(keyChain));
+
+				// Process new keys
+			} while (true);
+
+			return keySet;
+		}
+	}
+
 	protected SimpleTransaction convertToSimpleTransaction(BitcoinyTransaction t, Set<String> keySet) {
 		long amount = 0;
 		long total = 0L;

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

@@ -45,6 +45,9 @@ public class Digibyte extends Bitcoiny {
 				return Arrays.asList(
 						// Servers chosen on NO BASIS WHATSOEVER from various sources!
 						// Status verified at https://1209k.com/bitcoin-eye/ele.php?chain=dgb
+						new Server("electrum.qortal.link", Server.ConnectionType.SSL, 55002),
+						new Server("electrum-dgb.qortal.online", ConnectionType.SSL, 50002),
+						new Server("electrum1-dgb.qortal.online", ConnectionType.SSL, 50002),
 						new Server("electrum1.cipig.net", ConnectionType.SSL, 20059),
 						new Server("electrum2.cipig.net", ConnectionType.SSL, 20059),
 						new Server("electrum3.cipig.net", ConnectionType.SSL, 20059));
@@ -134,6 +137,8 @@ public class Digibyte extends Bitcoiny {
 			Context bitcoinjContext = new Context(digibyteNet.getParams());
 
 			instance = new Digibyte(digibyteNet, electrumX, bitcoinjContext, CURRENCY_CODE);
+
+			electrumX.setBlockchain(instance);
 		}
 
 		return instance;

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

@@ -45,10 +45,13 @@ public class Dogecoin extends Bitcoiny {
 			public Collection<Server> getServers() {
 				return Arrays.asList(
 						// Servers chosen on NO BASIS WHATSOEVER from various sources!
+						// Status verified at https://1209k.com/bitcoin-eye/ele.php?chain=doge
+						new Server("electrum.qortal.link", Server.ConnectionType.SSL, 54002),
+						new Server("electrum-doge.qortal.online", ConnectionType.SSL, 50002),
+						new Server("electrum1-doge.qortal.online", ConnectionType.SSL, 50002),
 						new Server("electrum1.cipig.net", ConnectionType.SSL, 20060),
 						new Server("electrum2.cipig.net", ConnectionType.SSL, 20060),
 						new Server("electrum3.cipig.net", ConnectionType.SSL, 20060));
-						// TODO: add more mainnet servers. It's too centralized.
 			}
 
 			@Override

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

@@ -5,6 +5,7 @@ import java.math.BigDecimal;
 import java.net.InetSocketAddress;
 import java.net.Socket;
 import java.net.SocketAddress;
+import java.text.DecimalFormat;
 import java.util.*;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
@@ -30,7 +31,11 @@ public class ElectrumX extends BitcoinyBlockchainProvider {
 	private static final Logger LOGGER = LogManager.getLogger(ElectrumX.class);
 	private static final Random RANDOM = new Random();
 
+	// See: https://electrumx.readthedocs.io/en/latest/protocol-changes.html
 	private static final double MIN_PROTOCOL_VERSION = 1.2;
+	private static final double MAX_PROTOCOL_VERSION = 2.0; // Higher than current latest, for hopeful future-proofing
+	private static final String CLIENT_NAME = "Qortal";
+
 	private static final int BLOCK_HEADER_LENGTH = 80;
 
 	// "message": "daemon error: DaemonError({'code': -5, 'message': 'No such mempool or blockchain transaction. Use gettransaction for wallet transactions.'})"
@@ -40,7 +45,7 @@ public class ElectrumX extends BitcoinyBlockchainProvider {
 	private static final String VERBOSE_TRANSACTIONS_UNSUPPORTED_MESSAGE = "verbose transactions are currently unsupported";
 
 	private static final int RESPONSE_TIME_READINGS = 5;
-	private static final long MAX_AVG_RESPONSE_TIME = 500L; // ms
+	private static final long MAX_AVG_RESPONSE_TIME = 1000L; // ms
 
 	public static class Server {
 		String hostname;
@@ -679,6 +684,9 @@ public class ElectrumX extends BitcoinyBlockchainProvider {
 				this.scanner = new Scanner(this.socket.getInputStream());
 				this.scanner.useDelimiter("\n");
 
+				// All connections need to start with a version negotiation
+				this.connectedRpc("server.version");
+
 				// Check connection is suitable by asking for server features, including genesis block hash
 				JSONObject featuresJson = (JSONObject) this.connectedRpc("server.features");
 
@@ -725,6 +733,17 @@ public class ElectrumX extends BitcoinyBlockchainProvider {
 
 		JSONArray requestParams = new JSONArray();
 		requestParams.addAll(Arrays.asList(params));
+
+		// server.version needs additional params to negotiate a version
+		if (method.equals("server.version")) {
+			requestParams.add(CLIENT_NAME);
+			List<String> versions = new ArrayList<>();
+			DecimalFormat df = new DecimalFormat("#.#");
+			versions.add(df.format(MIN_PROTOCOL_VERSION));
+			versions.add(df.format(MAX_PROTOCOL_VERSION));
+			requestParams.add(versions);
+		}
+
 		requestJson.put("params", requestParams);
 
 		String request = requestJson.toJSONString() + "\n";

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

@@ -45,15 +45,19 @@ public class Litecoin extends Bitcoiny {
 				return Arrays.asList(
 						// Servers chosen on NO BASIS WHATSOEVER from various sources!
 						// Status verified at https://1209k.com/bitcoin-eye/ele.php?chain=ltc
-						//CLOSED new Server("electrum-ltc.petrkr.net", Server.ConnectionType.SSL, 60002),
 						//CLOSED new Server("electrum-ltc.someguy123.net", Server.ConnectionType.SSL, 50002),
+						//CLOSED new Server("ltc.litepay.ch", Server.ConnectionType.SSL, 50022),
+						//BEHIND new Server("62.171.169.176", Server.ConnectionType.SSL, 50002),
 						//PHISHY new Server("electrum-ltc.bysh.me", Server.ConnectionType.SSL, 50002),
 						new Server("backup.electrum-ltc.org", Server.ConnectionType.SSL, 443),
+						new Server("electrum.qortal.link", Server.ConnectionType.SSL, 50002),
 						new Server("electrum.ltc.xurious.com", Server.ConnectionType.SSL, 50002),
+						new Server("electrum-ltc.petrkr.net", Server.ConnectionType.SSL, 60002),
+						new Server("electrum-ltc.qortal.online", Server.ConnectionType.SSL, 50002),
+						new Server("electrum1-ltc.qortal.online", Server.ConnectionType.SSL, 50002),
 						new Server("electrum1.cipig.net", Server.ConnectionType.SSL, 20063),
 						new Server("electrum2.cipig.net", Server.ConnectionType.SSL, 20063),
 						new Server("electrum3.cipig.net", Server.ConnectionType.SSL, 20063),
-						new Server("ltc.litepay.ch", Server.ConnectionType.SSL, 50022),
 						new Server("ltc.rentonrisk.com", Server.ConnectionType.SSL, 50002));
 			}
 

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

@@ -57,9 +57,9 @@ public class PirateChain extends Bitcoiny {
 			public Collection<Server> getServers() {
 				return Arrays.asList(
 						// Servers chosen on NO BASIS WHATSOEVER from various sources!
-						new Server("arrrlightd.qortal.online", ConnectionType.SSL, 443),
-						new Server("arrrlightd1.qortal.online", ConnectionType.SSL, 443),
-						new Server("arrrlightd2.qortal.online", ConnectionType.SSL, 443),
+						new Server("wallet-arrr1.qortal.online", ConnectionType.SSL, 443),
+						new Server("wallet-arrr2.qortal.online", ConnectionType.SSL, 443),
+						new Server("wallet-arrr3.qortal.online", ConnectionType.SSL, 443),
 						new Server("lightd.pirate.black", ConnectionType.SSL, 443));
 			}
 

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

@@ -117,7 +117,7 @@ public class PirateWallet {
                 // Restore existing wallet
                 String response = LiteWalletJni.initfromb64(serverUri, params, wallet, saplingOutput64, saplingSpend64);
                 if (response != null && !response.contains("\"initalized\":true")) {
-                    LOGGER.info("Unable to initialize Pirate Chain wallet: {}", response);
+                    LOGGER.info("Unable to initialize Pirate Chain wallet at {}: {}", serverUri, response);
                     return false;
                 }
                 this.seedPhrase = inputSeedPhrase;

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

@@ -45,13 +45,17 @@ public class Ravencoin extends Bitcoiny {
 				return Arrays.asList(
 						// Servers chosen on NO BASIS WHATSOEVER from various sources!
 						// Status verified at https://1209k.com/bitcoin-eye/ele.php?chain=rvn
-						new Server("aethyn.com", ConnectionType.SSL, 50002),
-						new Server("electrum2.rvn.rocks", ConnectionType.SSL, 50002),
-						new Server("rvn-dashboard.com", ConnectionType.SSL, 50002),
-						new Server("rvn4lyfe.com", ConnectionType.SSL, 50002),
+						//CLOSED new Server("aethyn.com", ConnectionType.SSL, 50002),
+						//CLOSED new Server("electrum2.rvn.rocks", ConnectionType.SSL, 50002),
+						//BEHIND new Server("electrum3.rvn.rocks", ConnectionType.SSL, 50002),
+						new Server("electrum.qortal.link", Server.ConnectionType.SSL, 56002),
+						new Server("electrum-rvn.qortal.online", ConnectionType.SSL, 50002),
+						new Server("electrum1-rvn.qortal.online", ConnectionType.SSL, 50002),
 						new Server("electrum1.cipig.net", ConnectionType.SSL, 20051),
 						new Server("electrum2.cipig.net", ConnectionType.SSL, 20051),
-						new Server("electrum3.cipig.net", ConnectionType.SSL, 20051));
+						new Server("electrum3.cipig.net", ConnectionType.SSL, 20051),
+						new Server("rvn-dashboard.com", ConnectionType.SSL, 50002),
+						new Server("rvn4lyfe.com", ConnectionType.SSL, 50002));
 			}
 
 			@Override
@@ -138,6 +142,8 @@ public class Ravencoin extends Bitcoiny {
 			Context bitcoinjContext = new Context(ravencoinNet.getParams());
 
 			instance = new Ravencoin(ravencoinNet, electrumX, bitcoinjContext, CURRENCY_CODE);
+
+			electrumX.setBlockchain(instance);
 		}
 
 		return instance;

src/main/java/org/qortal/crypto/AES.java

@@ -202,4 +202,12 @@ public class AES {
                 .decode(cipherText)));
     }
 
+    public static long getEncryptedFileSize(long inFileSize) {
+        // To calculate the resulting file size, add 16 (for the IV), then round up to the nearest multiple of 16
+        final int ivSize = 16;
+        final int chunkSize = 16;
+        final int expectedSize = Math.round((inFileSize + ivSize) / chunkSize) * chunkSize + chunkSize;
+        return expectedSize;
+    }
+
 }

src/main/java/org/qortal/data/arbitrary/ArbitraryResourceInfo.java

@@ -16,10 +16,17 @@ public class ArbitraryResourceInfo {
 	public ArbitraryResourceMetadata metadata;
 
 	public Long size;
+	public Long created;
+	public Long updated;
 
 	public ArbitraryResourceInfo() {
 	}
 
+	@Override
+	public String toString() {
+		return String.format("%s %s %s", name, service, identifier);
+	}
+
 	@Override
 	public boolean equals(Object o) {
 		if (o == this)

src/main/java/org/qortal/data/arbitrary/ArbitraryResourceMetadata.java

@@ -15,22 +15,26 @@ public class ArbitraryResourceMetadata {
     private List<String> tags;
     private Category category;
     private String categoryName;
+    private List<String> files;
+    private String mimeType;
 
     public ArbitraryResourceMetadata() {
     }
 
-    public ArbitraryResourceMetadata(String title, String description, List<String> tags, Category category) {
+    public ArbitraryResourceMetadata(String title, String description, List<String> tags, Category category, List<String> files, String mimeType) {
         this.title = title;
         this.description = description;
         this.tags = tags;
         this.category = category;
+        this.files = files;
+        this.mimeType = mimeType;
 
         if (category != null) {
             this.categoryName = category.getName();
         }
     }
 
-    public static ArbitraryResourceMetadata fromTransactionMetadata(ArbitraryDataTransactionMetadata transactionMetadata) {
+    public static ArbitraryResourceMetadata fromTransactionMetadata(ArbitraryDataTransactionMetadata transactionMetadata, boolean includeFileList) {
         if (transactionMetadata == null) {
             return null;
         }
@@ -38,11 +42,22 @@ public class ArbitraryResourceMetadata {
         String description = transactionMetadata.getDescription();
         List<String> tags = transactionMetadata.getTags();
         Category category = transactionMetadata.getCategory();
+        String mimeType = transactionMetadata.getMimeType();
 
-        if (title == null && description == null && tags == null && category == null) {
+        // We don't always want to include the file list as it can be too verbose
+        List<String> files = null;
+        if (includeFileList) {
+            files = transactionMetadata.getFiles();
+        }
+
+        if (title == null && description == null && tags == null && category == null && files == null && mimeType == null) {
             return null;
         }
 
-        return new ArbitraryResourceMetadata(title, description, tags, category);
+        return new ArbitraryResourceMetadata(title, description, tags, category, files, mimeType);
+    }
+
+    public List<String> getFiles() {
+        return this.files;
     }
 }

src/main/java/org/qortal/data/arbitrary/ArbitraryResourceStatus.java

@@ -8,6 +8,7 @@ public class ArbitraryResourceStatus {
 
     public enum Status {
         PUBLISHED("Published", "Published but not yet downloaded"),
+        NOT_PUBLISHED("Not published", "Resource does not exist"),
         DOWNLOADING("Downloading", "Locating and downloading files..."),
         DOWNLOADED("Downloaded", "Files downloaded"),
         BUILDING("Building", "Building..."),
@@ -33,6 +34,7 @@ public class ArbitraryResourceStatus {
 
     private Integer localChunkCount;
     private Integer totalChunkCount;
+    private Float percentLoaded;
 
     public ArbitraryResourceStatus() {
     }
@@ -44,6 +46,7 @@ public class ArbitraryResourceStatus {
         this.description = status.description;
         this.localChunkCount = localChunkCount;
         this.totalChunkCount = totalChunkCount;
+        this.percentLoaded = (this.localChunkCount != null && this.totalChunkCount != null) ? this.localChunkCount / (float)this.totalChunkCount * 100.0f : null;
     }
 
     public ArbitraryResourceStatus(Status status) {

src/main/java/org/qortal/data/chat/ActiveChats.java

@@ -1,10 +1,15 @@
 package org.qortal.data.chat;
 
+import org.bouncycastle.util.encoders.Base64;
+import org.qortal.utils.Base58;
+
 import java.util.List;
 
 import javax.xml.bind.annotation.XmlAccessType;
 import javax.xml.bind.annotation.XmlAccessorType;
 
+import static org.qortal.data.chat.ChatMessage.Encoding;
+
 @XmlAccessorType(XmlAccessType.FIELD)
 public class ActiveChats {
 
@@ -17,17 +22,39 @@ public class ActiveChats {
 		private Long timestamp;
 		private String sender;
 		private String senderName;
+		private byte[] signature;
+		private Encoding encoding;
+		private String data;
 
 		protected GroupChat() {
 			/* JAXB */
 		}
 
-		public GroupChat(int groupId, String groupName, Long timestamp, String sender, String senderName) {
+		public GroupChat(int groupId, String groupName, Long timestamp, String sender, String senderName,
+						 byte[] signature, Encoding encoding, byte[] data) {
 			this.groupId = groupId;
 			this.groupName = groupName;
 			this.timestamp = timestamp;
 			this.sender = sender;
 			this.senderName = senderName;
+			this.signature = signature;
+			this.encoding = encoding != null ? encoding : Encoding.BASE58;
+
+			if (data != null) {
+				switch (this.encoding) {
+					case BASE64:
+						this.data = Base64.toBase64String(data);
+						break;
+
+					case BASE58:
+					default:
+						this.data = Base58.encode(data);
+						break;
+				}
+			}
+			else {
+				this.data = null;
+			}
 		}
 
 		public int getGroupId() {
@@ -49,6 +76,14 @@ public class ActiveChats {
 		public String getSenderName() {
 			return this.senderName;
 		}
+
+		public byte[] getSignature() {
+			return this.signature;
+		}
+
+		public String getData() {
+			return this.data;
+		}
 	}
 
 	@XmlAccessorType(XmlAccessType.FIELD)
@@ -118,4 +153,4 @@ public class ActiveChats {
 		return this.direct;
 	}
 
-}
+}

src/main/java/org/qortal/data/chat/ChatMessage.java

@@ -1,11 +1,19 @@
 package org.qortal.data.chat;
 
+import org.bouncycastle.util.encoders.Base64;
+import org.qortal.utils.Base58;
+
 import javax.xml.bind.annotation.XmlAccessType;
 import javax.xml.bind.annotation.XmlAccessorType;
 
 @XmlAccessorType(XmlAccessType.FIELD)
 public class ChatMessage {
 
+	public enum Encoding {
+		BASE58,
+		BASE64
+	}
+
 	// Properties
 
 	private long timestamp;
@@ -27,7 +35,11 @@ public class ChatMessage {
 
 	private String recipientName;
 
-	private byte[] data;
+	private byte[] chatReference;
+
+	private Encoding encoding;
+
+	private String data;
 
 	private boolean isText;
 	private boolean isEncrypted;
@@ -42,8 +54,8 @@ public class ChatMessage {
 
 	// For repository use
 	public ChatMessage(long timestamp, int txGroupId, byte[] reference, byte[] senderPublicKey, String sender,
-			String senderName, String recipient, String recipientName, byte[] data, boolean isText,
-			boolean isEncrypted, byte[] signature) {
+					   String senderName, String recipient, String recipientName, byte[] chatReference,
+					   Encoding encoding, byte[] data, boolean isText, boolean isEncrypted, byte[] signature) {
 		this.timestamp = timestamp;
 		this.txGroupId = txGroupId;
 		this.reference = reference;
@@ -52,7 +64,25 @@ public class ChatMessage {
 		this.senderName = senderName;
 		this.recipient = recipient;
 		this.recipientName = recipientName;
-		this.data = data;
+		this.chatReference = chatReference;
+		this.encoding = encoding != null ? encoding : Encoding.BASE58;
+
+		if (data != null) {
+			switch (this.encoding) {
+				case BASE64:
+					this.data = Base64.toBase64String(data);
+					break;
+
+				case BASE58:
+				default:
+					this.data = Base58.encode(data);
+					break;
+			}
+		}
+		else {
+			this.data = null;
+		}
+
 		this.isText = isText;
 		this.isEncrypted = isEncrypted;
 		this.signature = signature;
@@ -90,7 +120,11 @@ public class ChatMessage {
 		return this.recipientName;
 	}
 
-	public byte[] getData() {
+	public byte[] getChatReference() {
+		return this.chatReference;
+	}
+
+	public String getData() {
 		return this.data;
 	}
 

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

@@ -73,7 +73,7 @@ public class ArbitraryTransactionData extends TransactionData {
 	@Schema(example = "sender_public_key")
 	private byte[] senderPublicKey;
 
-	private Service service;
+	private int service;
 	private int nonce;
 	private int size;
 
@@ -103,7 +103,7 @@ public class ArbitraryTransactionData extends TransactionData {
 	}
 
 	public ArbitraryTransactionData(BaseTransactionData baseTransactionData,
-									int version, Service service, int nonce, int size,
+									int version, int service, int nonce, int size,
 									String name, String identifier, Method method, byte[] secret, Compression compression,
 									byte[] data, DataType dataType, byte[] metadataHash, List<PaymentData> payments) {
 		super(TransactionType.ARBITRARY, baseTransactionData);
@@ -135,6 +135,10 @@ public class ArbitraryTransactionData extends TransactionData {
 	}
 
 	public Service getService() {
+		return Service.valueOf(this.service);
+	}
+
+	public int getServiceInt() {
 		return this.service;
 	}
 

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

@@ -3,6 +3,7 @@ package org.qortal.data.transaction;
 import javax.xml.bind.Unmarshaller;
 import javax.xml.bind.annotation.XmlAccessType;
 import javax.xml.bind.annotation.XmlAccessorType;
+import javax.xml.bind.annotation.XmlTransient;
 
 import org.qortal.transaction.Transaction.TransactionType;
 
@@ -19,6 +20,11 @@ public class CancelSellNameTransactionData extends TransactionData {
 	@Schema(description = "which name to cancel selling", example = "my-name")
 	private String name;
 
+	// For internal use when orphaning
+	@XmlTransient
+	@Schema(hidden = true)
+	private Long salePrice;
+
 	// Constructors
 
 	// For JAXB
@@ -30,11 +36,17 @@ public class CancelSellNameTransactionData extends TransactionData {
 		this.creatorPublicKey = this.ownerPublicKey;
 	}
 
-	public CancelSellNameTransactionData(BaseTransactionData baseTransactionData, String name) {
+	public CancelSellNameTransactionData(BaseTransactionData baseTransactionData, String name, Long salePrice) {
 		super(TransactionType.CANCEL_SELL_NAME, baseTransactionData);
 
 		this.ownerPublicKey = baseTransactionData.creatorPublicKey;
 		this.name = name;
+		this.salePrice = salePrice;
+	}
+
+	/** From network/API */
+	public CancelSellNameTransactionData(BaseTransactionData baseTransactionData, String name) {
+		this(baseTransactionData, name, null);
 	}
 
 	// Getters / setters
@@ -47,4 +59,12 @@ public class CancelSellNameTransactionData extends TransactionData {
 		return this.name;
 	}
 
+	public Long getSalePrice() {
+		return this.salePrice;
+	}
+
+	public void setSalePrice(Long salePrice) {
+		this.salePrice = salePrice;
+	}
+
 }

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

@@ -26,6 +26,8 @@ public class ChatTransactionData extends TransactionData {
 
 	private String recipient; // can be null
 
+	private byte[] chatReference; // can be null
+
 	@Schema(description = "raw message data, possibly UTF8 text", example = "2yGEbwRFyhPZZckKA")
 	private byte[] data;
 
@@ -44,13 +46,14 @@ public class ChatTransactionData extends TransactionData {
 	}
 
 	public ChatTransactionData(BaseTransactionData baseTransactionData,
-			String sender, int nonce, String recipient, byte[] data, boolean isText, boolean isEncrypted) {
+			String sender, int nonce, String recipient, byte[] chatReference, byte[] data, boolean isText, boolean isEncrypted) {
 		super(TransactionType.CHAT, baseTransactionData);
 
 		this.senderPublicKey = baseTransactionData.creatorPublicKey;
 		this.sender = sender;
 		this.nonce = nonce;
 		this.recipient = recipient;
+		this.chatReference = chatReference;
 		this.data = data;
 		this.isText = isText;
 		this.isEncrypted = isEncrypted;
@@ -78,6 +81,14 @@ public class ChatTransactionData extends TransactionData {
 		return this.recipient;
 	}
 
+	public byte[] getChatReference() {
+		return this.chatReference;
+	}
+
+	public void setChatReference(byte[] chatReference) {
+		this.chatReference = chatReference;
+	}
+
 	public byte[] getData() {
 		return this.data;
 	}

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

@@ -2,9 +2,11 @@ package org.qortal.data.transaction;
 
 import java.util.List;
 
+import javax.xml.bind.Unmarshaller;
 import javax.xml.bind.annotation.XmlAccessType;
 import javax.xml.bind.annotation.XmlAccessorType;
 
+import org.eclipse.persistence.oxm.annotations.XmlDiscriminatorValue;
 import org.qortal.data.voting.PollOptionData;
 import org.qortal.transaction.Transaction;
 import org.qortal.transaction.Transaction.TransactionType;
@@ -14,8 +16,13 @@ import io.swagger.v3.oas.annotations.media.Schema;
 // All properties to be converted to JSON via JAXB
 @XmlAccessorType(XmlAccessType.FIELD)
 @Schema(allOf = { TransactionData.class })
+@XmlDiscriminatorValue("CREATE_POLL")
 public class CreatePollTransactionData extends TransactionData {
 
+
+	@Schema(description = "Poll creator's public key", example = "2tiMr5LTpaWCgbRvkPK8TFd7k63DyHJMMFFsz9uBf1ZP")
+	private byte[] pollCreatorPublicKey;
+	
 	// Properties
 	private String owner;
 	private String pollName;
@@ -29,10 +36,15 @@ public class CreatePollTransactionData extends TransactionData {
 		super(TransactionType.CREATE_POLL);
 	}
 
+	public void afterUnmarshal(Unmarshaller u, Object parent) {
+		this.creatorPublicKey = this.pollCreatorPublicKey;
+	}
+	
 	public CreatePollTransactionData(BaseTransactionData baseTransactionData,
 			String owner, String pollName, String description, List<PollOptionData> pollOptions) {
 		super(Transaction.TransactionType.CREATE_POLL, baseTransactionData);
 
+		this.creatorPublicKey = baseTransactionData.creatorPublicKey;
 		this.owner = owner;
 		this.pollName = pollName;
 		this.description = description;
@@ -41,6 +53,7 @@ public class CreatePollTransactionData extends TransactionData {
 
 	// Getters/setters
 
+	public byte[] getPollCreatorPublicKey() { return this.creatorPublicKey; }
 	public String getOwner() {
 		return this.owner;
 	}

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

@@ -2,6 +2,7 @@ package org.qortal.data.transaction;
 
 import javax.xml.bind.annotation.XmlAccessType;
 import javax.xml.bind.annotation.XmlAccessorType;
+import javax.xml.bind.annotation.XmlElement;
 import javax.xml.bind.annotation.adapters.XmlJavaTypeAdapter;
 
 import org.qortal.transaction.Transaction.TransactionType;
@@ -90,4 +91,17 @@ public class DeployAtTransactionData extends TransactionData {
 		this.aTAddress = AtAddress;
 	}
 
+	// Re-expose creatorPublicKey for this transaction type for JAXB
+	@XmlElement(name = "creatorPublicKey")
+	@Schema(name = "creatorPublicKey", description = "AT creator's public key", example = "2tiMr5LTpaWCgbRvkPK8TFd7k63DyHJMMFFsz9uBf1ZP")
+	public byte[] getAtCreatorPublicKey() {
+		return this.creatorPublicKey;
+	}
+
+	@XmlElement(name = "creatorPublicKey")
+	@Schema(name = "creatorPublicKey", description = "AT creator's public key", example = "2tiMr5LTpaWCgbRvkPK8TFd7k63DyHJMMFFsz9uBf1ZP")
+	public void setAtCreatorPublicKey(byte[] creatorPublicKey) {
+		this.creatorPublicKey = creatorPublicKey;
+	}
+
 }

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

@@ -12,6 +12,7 @@ import javax.xml.bind.annotation.adapters.XmlJavaTypeAdapter;
 
 import org.eclipse.persistence.oxm.annotations.XmlDiscriminatorNode;
 import org.qortal.crypto.Crypto;
+import org.qortal.data.voting.PollData;
 import org.qortal.transaction.Transaction.ApprovalStatus;
 import org.qortal.transaction.Transaction.TransactionType;
 
@@ -29,6 +30,7 @@ import io.swagger.v3.oas.annotations.media.Schema.AccessMode;
 @XmlSeeAlso({GenesisTransactionData.class, PaymentTransactionData.class, RegisterNameTransactionData.class, UpdateNameTransactionData.class,
 	SellNameTransactionData.class, CancelSellNameTransactionData.class, BuyNameTransactionData.class,
 	CreatePollTransactionData.class, VoteOnPollTransactionData.class, ArbitraryTransactionData.class,
+	PollData.class,
 	IssueAssetTransactionData.class, TransferAssetTransactionData.class,
 	CreateAssetOrderTransactionData.class, CancelAssetOrderTransactionData.class,
 	MultiPaymentTransactionData.class, DeployAtTransactionData.class, MessageTransactionData.class, ATTransactionData.class,

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

@@ -3,7 +3,9 @@ package org.qortal.data.transaction;
 import javax.xml.bind.Unmarshaller;
 import javax.xml.bind.annotation.XmlAccessType;
 import javax.xml.bind.annotation.XmlAccessorType;
+import javax.xml.bind.annotation.XmlTransient;
 
+import org.eclipse.persistence.oxm.annotations.XmlDiscriminatorValue;
 import org.qortal.transaction.Transaction.TransactionType;
 
 import io.swagger.v3.oas.annotations.media.Schema;
@@ -11,12 +13,17 @@ import io.swagger.v3.oas.annotations.media.Schema;
 // All properties to be converted to JSON via JAXB
 @XmlAccessorType(XmlAccessType.FIELD)
 @Schema(allOf = { TransactionData.class })
+@XmlDiscriminatorValue("VOTE_ON_POLL")
 public class VoteOnPollTransactionData extends TransactionData {
 
 	// Properties
+	@Schema(description = "Vote creator's public key", example = "2tiMr5LTpaWCgbRvkPK8TFd7k63DyHJMMFFsz9uBf1ZP")
 	private byte[] voterPublicKey;
 	private String pollName;
 	private int optionIndex;
+	// For internal use when orphaning
+	@XmlTransient
+	@Schema(hidden = true)
 	private Integer previousOptionIndex;
 
 	// Constructors

src/main/java/org/qortal/data/voting/PollData.java

@@ -14,6 +14,11 @@ public class PollData {
 
 	// Constructors
 
+	// For JAXB
+	protected PollData() {
+		super();
+	}
+
 	public PollData(byte[] creatorPublicKey, String owner, String pollName, String description, List<PollOptionData> pollOptions, long published) {
 		this.creatorPublicKey = creatorPublicKey;
 		this.owner = owner;
@@ -29,22 +34,42 @@ public class PollData {
 		return this.creatorPublicKey;
 	}
 
+	public void setCreatorPublicKey(byte[] creatorPublicKey) {
+		this.creatorPublicKey = creatorPublicKey;
+	}
+
 	public String getOwner() {
 		return this.owner;
 	}
 
+	public void setOwner(String owner) {
+		this.owner = owner;
+	}
+
 	public String getPollName() {
 		return this.pollName;
 	}
 
+	public void setPollName(String pollName) {
+		this.pollName = pollName;
+	}
+
 	public String getDescription() {
 		return this.description;
 	}
 
+	public void setDescription(String description) {
+		this.description = description;
+	}
+
 	public List<PollOptionData> getPollOptions() {
 		return this.pollOptions;
 	}
 
+	public void setPollOptions(List<PollOptionData> pollOptions) {
+		this.pollOptions = pollOptions;
+	}
+
 	public long getPublished() {
 		return this.published;
 	}

src/main/java/org/qortal/list/ResourceList.java

@@ -52,6 +52,15 @@ public class ResourceList {
         String jsonString = ResourceList.listToJSONString(this.list);
         Path filePath = this.getFilePath();
 
+        // Don't create list if it's empty
+        if (this.list != null && this.list.isEmpty()) {
+            if (filePath != null && Files.exists(filePath)) {
+                // Delete empty list
+                Files.delete(filePath);
+            }
+            return;
+        }
+
         // Create parent directory if needed
         try {
             Files.createDirectories(filePath.getParent());
@@ -109,6 +118,13 @@ public class ResourceList {
         this.list.remove(resource);
     }
 
+    public void clear() {
+        if (this.list == null) {
+            return;
+        }
+        this.list.clear();
+    }
+
     public boolean contains(String resource, boolean caseSensitive) {
         if (resource == null || this.list == null) {
             return false;

src/main/java/org/qortal/list/ResourceListManager.java

@@ -2,8 +2,11 @@ package org.qortal.list;
 
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
+import org.qortal.settings.Settings;
 
 import java.io.IOException;
+import java.nio.file.Path;
+import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
@@ -18,6 +21,7 @@ public class ResourceListManager {
 
 
     public ResourceListManager() {
+        this.lists = this.fetchLists();
     }
 
     public static synchronized ResourceListManager getInstance() {
@@ -27,6 +31,38 @@ public class ResourceListManager {
         return instance;
     }
 
+    public static synchronized void reset() {
+        if (instance != null) {
+            instance = null;
+        }
+    }
+
+    private List<ResourceList> fetchLists() {
+        List<ResourceList> lists = new ArrayList<>();
+        Path listsPath = Paths.get(Settings.getInstance().getListsPath());
+
+        if (listsPath.toFile().isDirectory()) {
+            String[] files = listsPath.toFile().list();
+
+            for (String fileName : files) {
+                try {
+                    // Remove .json extension
+                    if (fileName.endsWith(".json")) {
+                        fileName = fileName.substring(0, fileName.length() - 5);
+                    }
+
+                    ResourceList list = new ResourceList(fileName);
+                    if (list != null) {
+                        lists.add(list);
+                    }
+                } catch (IOException e) {
+                    // Ignore this list
+                }
+            }
+        }
+        return lists;
+    }
+
     private ResourceList getList(String listName) {
         for (ResourceList list : this.lists) {
             if (Objects.equals(list.getName(), listName)) {
@@ -48,6 +84,18 @@ public class ResourceListManager {
 
     }
 
+    private List<ResourceList> getListsByPrefix(String listNamePrefix) {
+        List<ResourceList> lists = new ArrayList<>();
+
+        for (ResourceList list : this.lists) {
+            if (list != null && list.getName() != null && list.getName().startsWith(listNamePrefix)) {
+                lists.add(list);
+            }
+        }
+
+        return lists;
+    }
+
     public boolean addToList(String listName, String item, boolean save) {
         ResourceList list = this.getList(listName);
         if (list == null) {
@@ -95,6 +143,16 @@ public class ResourceListManager {
         return list.contains(item, caseSensitive);
     }
 
+    public boolean listWithPrefixContains(String listNamePrefix, String item, boolean caseSensitive) {
+        List<ResourceList> lists = getListsByPrefix(listNamePrefix);
+        for (ResourceList list : lists) {
+            if (list.contains(item, caseSensitive)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
     public void saveList(String listName) {
         ResourceList list = this.getList(listName);
         if (list == null) {
@@ -133,6 +191,15 @@ public class ResourceListManager {
         return list.getList();
     }
 
+    public List<String> getStringsInListsWithPrefix(String listNamePrefix) {
+        List<String> items = new ArrayList<>();
+        List<ResourceList> lists = getListsByPrefix(listNamePrefix);
+        for (ResourceList list : lists) {
+            items.addAll(list.getList());
+        }
+        return items;
+    }
+
     public int getItemCountForList(String listName) {
         ResourceList list = this.getList(listName);
         if (list == null) {

src/main/java/org/qortal/naming/Name.java

@@ -16,6 +16,8 @@ import org.qortal.repository.Repository;
 import org.qortal.transaction.Transaction.TransactionType;
 import org.qortal.utils.Unicode;
 
+import java.util.Objects;
+
 public class Name {
 
 	// Properties
@@ -116,7 +118,7 @@ public class Name {
 
 		this.repository.getNameRepository().save(this.nameData);
 
-		if (!updateNameTransactionData.getNewName().isEmpty())
+		if (!updateNameTransactionData.getNewName().isEmpty() && !Objects.equals(updateNameTransactionData.getName(), updateNameTransactionData.getNewName()))
 			// Name has changed, delete old entry
 			this.repository.getNameRepository().delete(updateNameTransactionData.getNewName());
 
@@ -180,8 +182,12 @@ public class Name {
 	}
 
 	public void cancelSell(CancelSellNameTransactionData cancelSellNameTransactionData) throws DataException {
-		// Mark not for-sale but leave price in case we want to orphan
+		// Update previous sale price in transaction data
+		cancelSellNameTransactionData.setSalePrice(this.nameData.getSalePrice());
+
+		// Mark not for-sale
 		this.nameData.setIsForSale(false);
+		this.nameData.setSalePrice(null);
 
 		// Save sale info into repository
 		this.repository.getNameRepository().save(this.nameData);
@@ -190,6 +196,7 @@ public class Name {
 	public void uncancelSell(CancelSellNameTransactionData cancelSellNameTransactionData) throws DataException {
 		// Mark as for-sale using existing price
 		this.nameData.setIsForSale(true);
+		this.nameData.setSalePrice(cancelSellNameTransactionData.getSalePrice());
 
 		// Save no-sale info into repository
 		this.repository.getNameRepository().save(this.nameData);

src/main/java/org/qortal/network/Handshake.java

@@ -265,7 +265,7 @@ public enum Handshake {
 	private static final long PEER_VERSION_131 = 0x0100030001L;
 
 	/** Minimum peer version that we are allowed to communicate with */
-	private static final String MIN_PEER_VERSION = "3.7.0";
+	private static final String MIN_PEER_VERSION = "3.8.2";
 
 	private static final int POW_BUFFER_SIZE_PRE_131 = 8 * 1024 * 1024; // bytes
 	private static final int POW_DIFFICULTY_PRE_131 = 8; // leading zero bits

src/main/java/org/qortal/network/Network.java

@@ -124,6 +124,8 @@ public class Network {
 
     private final List<PeerAddress> selfPeers = new ArrayList<>();
 
+    private String bindAddress = null;
+
     private final ExecuteProduceConsume networkEPC;
     private Selector channelSelector;
     private ServerSocketChannel serverChannel;
@@ -159,25 +161,43 @@ public class Network {
         // Grab P2P port from settings
         int listenPort = Settings.getInstance().getListenPort();
 
-        // Grab P2P bind address from settings
-        try {
-            InetAddress bindAddr = InetAddress.getByName(Settings.getInstance().getBindAddress());
-            InetSocketAddress endpoint = new InetSocketAddress(bindAddr, listenPort);
+        // Grab P2P bind addresses from settings
+        List<String> bindAddresses = new ArrayList<>();
+        if (Settings.getInstance().getBindAddress() != null) {
+            bindAddresses.add(Settings.getInstance().getBindAddress());
+        }
+        if (Settings.getInstance().getBindAddressFallback() != null) {
+            bindAddresses.add(Settings.getInstance().getBindAddressFallback());
+        }
 
-            channelSelector = Selector.open();
+        for (int i=0; i<bindAddresses.size(); i++) {
+            try {
+                String bindAddress = bindAddresses.get(i);
+                InetAddress bindAddr = InetAddress.getByName(bindAddress);
+                InetSocketAddress endpoint = new InetSocketAddress(bindAddr, listenPort);
 
-            // Set up listen socket
-            serverChannel = ServerSocketChannel.open();
-            serverChannel.configureBlocking(false);
-            serverChannel.setOption(StandardSocketOptions.SO_REUSEADDR, true);
-            serverChannel.bind(endpoint, LISTEN_BACKLOG);
-            serverSelectionKey = serverChannel.register(channelSelector, SelectionKey.OP_ACCEPT);
-        } catch (UnknownHostException e) {
-            LOGGER.error("Can't bind listen socket to address {}", Settings.getInstance().getBindAddress());
-            throw new IOException("Can't bind listen socket to address", e);
-        } catch (IOException e) {
-            LOGGER.error("Can't create listen socket: {}", e.getMessage());
-            throw new IOException("Can't create listen socket", e);
+                channelSelector = Selector.open();
+
+                // Set up listen socket
+                serverChannel = ServerSocketChannel.open();
+                serverChannel.configureBlocking(false);
+                serverChannel.setOption(StandardSocketOptions.SO_REUSEADDR, true);
+                serverChannel.bind(endpoint, LISTEN_BACKLOG);
+                serverSelectionKey = serverChannel.register(channelSelector, SelectionKey.OP_ACCEPT);
+
+                this.bindAddress = bindAddress; // Store the selected address, so that it can be used by other parts of the app
+                break; // We don't want to bind to more than one address
+            } catch (UnknownHostException e) {
+                LOGGER.error("Can't bind listen socket to address {}", Settings.getInstance().getBindAddress());
+                if (i == bindAddresses.size()-1) { // Only throw an exception if all addresses have been tried
+                    throw new IOException("Can't bind listen socket to address", e);
+                }
+            } catch (IOException e) {
+                LOGGER.error("Can't create listen socket: {}", e.getMessage());
+                if (i == bindAddresses.size()-1) { // Only throw an exception if all addresses have been tried
+                    throw new IOException("Can't create listen socket", e);
+                }
+            }
         }
 
         // Load all known peers from repository
@@ -228,6 +248,10 @@ public class Network {
         return this.maxPeers;
     }
 
+    public String getBindAddress() {
+        return this.bindAddress;
+    }
+
     public byte[] getMessageMagic() {
         return Settings.getInstance().isTestNet() ? TESTNET_MESSAGE_MAGIC : MAINNET_MESSAGE_MAGIC;
     }
@@ -339,7 +363,7 @@ public class Network {
                 try {
                     if (!isConnected) {
                         // Add this signature to the list of pending requests for this peer
-                        LOGGER.info("Making connection to peer {} to request files for signature {}...", peerAddressString, Base58.encode(signature));
+                        LOGGER.debug("Making connection to peer {} to request files for signature {}...", peerAddressString, Base58.encode(signature));
                         Peer peer = new Peer(peerData);
                         peer.setIsDataPeer(true);
                         peer.addPendingSignatureRequest(signature);
@@ -1556,7 +1580,7 @@ public class Network {
         this.isShuttingDown = true;
 
         // Close listen socket to prevent more incoming connections
-        if (this.serverChannel.isOpen()) {
+        if (this.serverChannel != null && this.serverChannel.isOpen()) {
             try {
                 this.serverChannel.close();
             } catch (IOException e) {

src/main/java/org/qortal/network/Peer.java

@@ -155,6 +155,11 @@ public class Peer {
      */
     private CommonBlockData commonBlockData;
 
+    /**
+     * Last time we detected this peer as TOO_DIVERGENT
+     */
+    private Long lastTooDivergentTime;
+
     // Message stats
 
     private static class MessageStats {
@@ -383,6 +388,14 @@ public class Peer {
         this.commonBlockData = commonBlockData;
     }
 
+    public Long getLastTooDivergentTime() {
+        return this.lastTooDivergentTime;
+    }
+
+    public void setLastTooDivergentTime(Long lastTooDivergentTime) {
+        this.lastTooDivergentTime = lastTooDivergentTime;
+    }
+
     public boolean isSyncInProgress() {
         return this.syncInProgress;
     }

src/main/java/org/qortal/network/message/CachedBlockV2Message.java

@@ -0,0 +1,43 @@
+package org.qortal.network.message;
+
+import com.google.common.primitives.Ints;
+import org.qortal.block.Block;
+import org.qortal.transform.TransformationException;
+import org.qortal.transform.block.BlockTransformer;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.nio.ByteBuffer;
+
+// This is an OUTGOING-only Message which more readily lends itself to being cached
+public class CachedBlockV2Message extends Message implements Cloneable {
+
+	public CachedBlockV2Message(Block block) throws TransformationException {
+		super(MessageType.BLOCK_V2);
+
+		ByteArrayOutputStream bytes = new ByteArrayOutputStream();
+
+		try {
+			bytes.write(Ints.toByteArray(block.getBlockData().getHeight()));
+
+			bytes.write(BlockTransformer.toBytes(block));
+		} catch (IOException e) {
+			throw new AssertionError("IOException shouldn't occur with ByteArrayOutputStream");
+		}
+
+		this.dataBytes = bytes.toByteArray();
+		this.checksumBytes = Message.generateChecksum(this.dataBytes);
+	}
+
+	public CachedBlockV2Message(byte[] cachedBytes) {
+		super(MessageType.BLOCK_V2);
+
+		this.dataBytes = cachedBytes;
+		this.checksumBytes = Message.generateChecksum(this.dataBytes);
+	}
+
+	public static Message fromByteBuffer(int id, ByteBuffer byteBuffer) {
+		throw new UnsupportedOperationException("CachedBlockMessageV2 is for outgoing messages only");
+	}
+
+}

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

@@ -119,7 +119,7 @@ public interface ATRepository {
 	 * <p>
 	 * NOTE: performs implicit <tt>repository.saveChanges()</tt>.
 	 */
-	public void rebuildLatestAtStates() throws DataException;
+	public void rebuildLatestAtStates(int maxHeight) throws DataException;
 
 
 	/** Returns height of first trimmable AT state. */