Added unit tests for level 3+4, 5+6, 7+8, and 9+10 rewards.

These are simpler than the level 1+2 tests; they only test that the rewards are correct for each level post-shareBinFix. I don't think we need multiple instances of the pre-shareBinFix or block orphaning tests. There are a few subtle differences between each test, such as the online status of Bob, in order the make the tests slightly more comprehensive.

.gitignore

@@ -16,3 +16,6 @@
 /settings*.json
 /testchain.json
 /run-testnet.sh
+/.idea
+/qortal.iml
+*.DS_Store

AutoUpdates.md

@@ -1,5 +1,20 @@
 # Auto Updates
 
+## TL;DR: how-to
+
+* Prepare new release version (see way below for details)
+* Assuming you are in git 'master' branch, at HEAD
+* Shutdown local node if running
+* Build auto-update download: `tools/build-auto-update.sh` - uploads auto-update file into new git branch
+* Restart local node
+* Publish auto-update transaction using *private key* for **non-admin** member of "dev" group:
+	`tools/publish-auto-update.sh non-admin-dev-member-private-key-in-base58`
+* Wait for auto-update `ARBITRARY` transaction to be confirmed into a block
+* Have "dev" group admins 'approve' auto-update using `tools/approve-auto-update.sh`
+	This tool will prompt for *private key* of **admin** of "dev" group
+* A minimum number of admins are required for approval, and a minimum number of blocks must pass also.
+* Nodes will start to download, and apply, the update over the next 20 minutes or so (see CHECK_INTERVAL in AutoUpdate.java)
+
 ## Theory
 * Using a specific git commit (e.g. abcdef123) we produce a determinstic JAR with consistent hash.
 * To avoid issues with over-eager anti-virus / firewalls we obfuscate JAR using very simplistic XOR-based method.
@@ -25,8 +40,8 @@ The same method is used to obfuscate and de-obfuscate:
 
 ## Typical download locations
 The git SHA1 commit hash is used to replace `%s` in various download locations, e.g.:
-* https://github.com/QORT/qortal/raw/%s/qortal.update
-* https://raw.githubusercontent.com@151.101.16.133/QORT/qortal/%s/qortal.update
+* https://github.com/Qortal/qortal/raw/%s/qortal.update
+* https://raw.githubusercontent.com@151.101.16.133/Qortal/qortal/%s/qortal.update
 
 These locations are part of the org.qortal.settings.Settings class and can be overriden in settings.json like:
 ```
@@ -45,4 +60,12 @@ $ java -cp qortal.jar org.qortal.XorUpdate
 usage: XorUpdate <input-file> <output-file>
 $ java -cp qortal.jar org.qortal.XorUpdate qortal.jar qortal.update
 $
-```
+```
+
+## Preparing new release version
+
+* Shutdown local node
+* Modify `pom.xml` and increase version inside `<version>` tag
+* Commit new `pom.xml` and push to github, e.g. `git commit -m 'Bumped to v1.4.2' -- pom.xml; git push`
+* Tag this new commit with same version: `git tag v1.4.2`
+* Push tag up to github: `git push origin v1.4.2`

DATABASE.md

@@ -4,10 +4,10 @@ You can examine your node's database using [HSQLDB's "sqltool"](http://www.hsqld
 It's a good idea to install "rlwrap" (ReadLine wrapper) too as sqltool doesn't support command history/editing.
 
 Typical command line for sqltool would be:
-`rlwrap java -cp ${HSQLDB_JAR}:${SQLTOOL_JAR} org.hsqldb.cmdline.SqlTool --rcFile=${SQLTOOL_RC} qora`
+`rlwrap java -cp ${HSQLDB_JAR}:${SQLTOOL_JAR} org.hsqldb.cmdline.SqlTool --rcFile=${SQLTOOL_RC} qortal`
 
 `${HSQLDB_JAR}` should be set with pathname where Maven downloaded hsqldb, 
-typically `${HOME}/.m2/repository/org/hsqldb/hsqldb/2.5.0/hsqldb-2.5.0.jar`
+typically `${HOME}/.m2/repository/org/hsqldb/hsqldb/2.5.1/hsqldb-2.5.1.jar`
 
 `${SQLTOOL_JAR}` should be set with pathname where Maven downloaded sqltool,
 typically  `${HOME}/.m2/repository/org/hsqldb/sqltool/2.5.0/sqltool-2.5.0.jar`
@@ -25,10 +25,16 @@ Above `url` component `file:db/blockchain` assumes you will call `sqltool` from
 
 Another idea is to assign a shell alias in your `.bashrc` like:
 ```
-export HSQLDB_JAR=${HOME}/.m2/repository/org/hsqldb/hsqldb/2.5.0/hsqldb-2.5.0.jar
+export HSQLDB_JAR=${HOME}/.m2/repository/org/hsqldb/hsqldb/2.5.1/hsqldb-2.5.1.jar
 export SQLTOOL_JAR=${HOME}/.m2/repository/org/hsqldb/sqltool/2.5.0/sqltool-2.5.0.jar
 alias sqltool='rlwrap java -cp ${HSQLDB_JAR}:${SQLTOOL_JAR} org.hsqldb.cmdline.SqlTool --rcFile=${SQLTOOL_RC}'
 ```
 So you can simply type: `sqltool qortal`
 
 Don't forget to use `SHUTDOWN;` before exiting sqltool so that database files are closed cleanly.
+
+## Quick and dirty version
+
+With `sqltool-2.5.0.jar` and `qortal.jar` in current directory, and database in `db/`
+
+`java -cp qortal.jar:sqltool-2.5.0.jar org.hsqldb.cmdline.SqlTool --inlineRc=url=jdbc:hsqldb:file:db/blockchain`

README.md

@@ -9,4 +9,4 @@
 - Create basic *settings.json* file: `echo '{}' > settings.json`
 - Run JAR in same working directory as *settings.json*: `java -jar target/qortal-1.0.jar`
 - Wrap in shell script, add JVM flags, redirection, backgrounding, etc. as necessary.
-- Or use supplied example shell script: *run.sh*
+- Or use supplied example shell script: *start.sh*

TestNets.md

@@ -0,0 +1,69 @@
+# How to build a testnet
+
+## Create testnet blockchain config
+
+- You can begin by copying the mainnet blockchain config `src/main/resources/blockchain.json`
+- Insert `"isTestChain": true,` after the opening `{`
+- Modify testnet genesis block
+
+### Testnet genesis block
+
+- Set `timestamp` to a nearby future value, e.g. 15 mins from 'now'
+	This is to give yourself enough time to set up other testnet nodes
+- Retain the initial `ISSUE_ASSET` transactions!
+- Add `ACCOUNT_FLAGS` transactions with `"andMask": -1, "orMask": 1, "xorMask": 0` to create founders
+- Add at least one `REWARD_SHARE` transaction otherwise no-one can mint initial blocks!
+	You will need to calculate `rewardSharePublicKey` (and private key),
+	or make a new account on mainnet and use self-share key values
+- Add `ACCOUNT_LEVEL` transactions to set initial level of accounts as needed
+- Add `GENESIS` transactions to add QORT/LEGACY_QORA funds to accounts as needed
+
+## Testnet `settings.json`
+
+- Create a new `settings-test.json`
+- Make sure to add `"isTestNet": true,`
+- Make sure to reference testnet blockchain config file: `"blockchainConfig": "testchain.json",`
+- It is a good idea to use a separate database: `"repositoryPath": "db-testnet",`
+- You might also need to add `"bitcoinNet": "TEST3",` and `"litecoinNet": "TEST3",`
+
+## Other nodes
+
+- Copy `testchain.json` and `settings-test.json` to other nodes
+- Alternatively, you can run multiple nodes on the same machine by:
+	* Copying `settings-test.json` to `settings-test-1.json`
+	* Configure different `repositoryPath`
+	* Configure use of different ports:
+		+ `"apiPort": 22391,`
+		+ `"listenPort": 22392,`
+
+## Starting-up
+
+- Start up at least as many nodes as `minBlockchainPeers` (or adjust this value instead)
+- Probably best to perform API call `DELETE /peers/known`
+- Add other nodes via API call `POST /peers <peer-hostname-or-IP>`
+- Add minting private key to node(s) via API call `POST /admin/mintingaccounts <minting-private-key>`
+	This key must have corresponding `REWARD_SHARE` transaction in testnet genesis block
+- Wait for genesis block timestamp to pass
+- A node should mint block 2 approximately 60 seconds after genesis block timestamp
+- Other testnet nodes will sync *as long as there is at least `minBlockchainPeers` peers with an "up-to-date" chain`
+- You can also use API call `POST /admin/forcesync <connected-peer-IP-and-port>` on stuck nodes
+
+## Dealing with stuck chain
+
+Maybe your nodes have been offline and no-one has minted a recent testnet block.
+Your options are:
+
+- Start a new testnet from scratch
+- Fire up your testnet node(s)
+- Force one of your nodes to mint by:
+	+ Set a debugger breakpoint on Settings.getMinBlockchainPeers()
+	+ When breakpoint is hit, change `this.minBlockchainPeers` to zero, then continue
+- Once one of your nodes has minted blocks up to 'now', you can use "forcesync" on the other nodes
+
+## Tools
+
+- `qort` tool, but use `-t` option for default testnet API port (62391)
+- `qort` tool, but first set shell variable: `export BASE_URL=some-node-hostname-or-ip:port`
+- `qort` tool, but prepend with one-time shell variable: `BASE_URL=some-node-hostname-or-ip:port qort ......`
+- `peer-heights`, but use `-t` option, or `BASE_URL` shell variable as above
+

WindowsInstaller/Install Files/AppData/settings.json

@@ -0,0 +1,3 @@
+{
+  "apiDocumentationEnabled": true
+}

WindowsInstaller/Install Files/log4j2.properties

@@ -0,0 +1,70 @@
+rootLogger.level = info
+# On Windows, uncomment next line to set dirname:
+# property.dirname = ${sys:user.home}\\AppData\\Local\\qortal\\
+property.filename = ${sys:log4j2.filenameTemplate:-log.txt}
+
+rootLogger.appenderRef.console.ref = stdout
+rootLogger.appenderRef.rolling.ref = FILE
+
+# Suppress extraneous bitcoinj library output
+logger.bitcoinj.name = org.bitcoinj
+logger.bitcoinj.level = error
+
+# Override HSQLDB logging level to "warn" as too much is logged at "info"
+logger.hsqldb.name = hsqldb.db
+logger.hsqldb.level = warn
+
+# Support optional, per-session HSQLDB debugging
+logger.hsqldbRepository.name = org.qortal.repository.hsqldb
+logger.hsqldbRepository.level = debug
+
+# Suppress extraneous Jersey warning
+logger.jerseyInject.name = org.glassfish.jersey.internal.inject.Providers
+logger.jerseyInject.level = off
+
+# Suppress extraneous Jersey EOF 'errors' (actually remote peers disconnecting early)
+logger.jerseyEOF.name = org.glassfish.jersey.server.internal
+logger.jerseyEOF.level = off
+
+# Suppress extraneous Jetty entries
+# 2019-02-14 11:46:27 INFO  ContextHandler:851 - Started o.e.j.s.ServletContextHandler@6949e948{/,null,AVAILABLE}
+# 2019-02-14 11:46:27 INFO  AbstractConnector:289 - Started ServerConnector@50ad322b{HTTP/1.1,[http/1.1]}{0.0.0.0:9085}
+# 2019-02-14 11:46:27 INFO  Server:374 - jetty-9.4.11.v20180605; built: 2018-06-05T18:24:03.829Z; git: d5fc0523cfa96bfebfbda19606cad384d772f04c; jvm 1.8.0_181-b13
+# 2019-02-14 11:46:27 INFO  Server:411 - Started @2539ms
+logger.jetty.name = org.eclipse.jetty
+logger.jetty.level = warn
+# Even more extraneous Jetty output
+# 2019-01-26 02:18:10 WARN  ResourceService:718 - java.util.concurrent.TimeoutException: Idle timeout expired: 30000/30000 ms
+logger.jettyRS.name = org.eclipse.jetty.server.ResourceService
+logger.jettyRS.level = error
+
+# Suppress extraneous slf4j entries
+# 2019-02-14 11:46:27 INFO  log:193 - Logging initialized @1636ms to org.eclipse.jetty.util.log.Slf4jLog
+logger.slf4j.name = org.slf4j
+logger.slf4j.level = warn
+
+# Suppress extraneous Reflections entry
+# 2019-02-27 10:45:25 WARN  Reflections:179 - given scan urls are empty. set urls in the configuration
+logger.orgReflections.name = org.reflections.Reflections
+logger.orgReflections.level = off
+logger.sunReflections.name = sun.reflect.Reflection
+logger.sunReflections.level = off
+
+appender.console.type = Console
+appender.console.name = stdout
+appender.console.layout.type = PatternLayout
+appender.console.layout.pattern = %d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n
+appender.console.filter.threshold.type = ThresholdFilter
+appender.console.filter.threshold.level = error
+
+appender.rolling.type = RollingFile
+appender.rolling.name = FILE
+appender.rolling.layout.type = PatternLayout
+appender.rolling.layout.pattern = %d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n
+appender.rolling.filePattern = ${dirname:-}${filename}.%i
+appender.rolling.policy.type = SizeBasedTriggeringPolicy
+appender.rolling.policy.size = 4MB
+# Set the immediate flush to true (default)
+# appender.rolling.immediateFlush = true
+# Set the append to true (default), should not overwrite
+# appender.rolling.append=true

WindowsInstaller/Install Files/ntpcfg.bat

@@ -0,0 +1,33 @@
+@echo off
+
+:: BatchGotAdmin
+:-------------------------------------
+REM  --> Check for permissions
+>nul 2>&1 "%SYSTEMROOT%\system32\cacls.exe" "%SYSTEMROOT%\system32\config\system"
+
+REM --> If error flag set, we do not have admin.
+if '%errorlevel%' NEQ '0' (
+    echo Requesting administrative privileges...
+    goto UACPrompt
+) else ( goto gotAdmin )
+
+:UACPrompt
+    echo Set UAC = CreateObject^("Shell.Application"^) > "%temp%\getadmin.vbs"
+    echo UAC.ShellExecute "%~s0", "", "", "runas", 1 >> "%temp%\getadmin.vbs"
+
+    "%temp%\getadmin.vbs"
+    exit /B
+
+:gotAdmin
+    if exist "%temp%\getadmin.vbs" ( del "%temp%\getadmin.vbs" )
+    pushd "%CD%"
+    CD /D "%~dp0"
+:--------------------------------------
+
+net stop "Windows Time"
+
+w32tm /config "/manualpeerlist:pool.ntp.org 0.pool.ntp.org 1.pool.ntp.org 2.pool.ntp.org 3.pool.ntp.org cn.pool.ntp.org 0.cn.pool.ntp.org 1.cn.pool.ntp.org 2.cn.pool.ntp.org 3.cn.pool.ntp.org"
+
+net start "Windows Time"
+
+sc config w32time start= auto

WindowsInstaller/README.md

@@ -0,0 +1,26 @@
+# Windows installer
+
+## Prerequisites
+
+* AdvancedInstaller v16 or better, and enterprise licence if translations are required
+* Installed AdoptOpenJDK v11 64bit, full JDK *not* JRE
+
+## General build instructions
+
+If this is your first time opening the `qortal.aip` file then you might need to adjust
+configured paths, or create a dummy `D:` drive with the expected layout.
+
+Typical build procedure:
+
+* Overwrite the `qortal.jar` file in `Install-Files\`
+* Open AdvancedInstaller with qortal.aip file
+* If releasing a new version, change version number in:
+	+ "Product Information" side menu
+	+ "Product Details" side menu entry
+	+ "Product Details" tab in "Product Details" pane
+	+ "Product Version" entry box
+* Click away to a different side menu entry, e.g. "Resources" -> "Files and Folders"
+* You should be prompted whether to generate a new product key, click "Generate New"
+* Click "Build" button
+* New EXE should be generated in `Qortal-SetupFiles\` folder with correct version number
+

WindowsInstaller/dictionary.ail

@@ -0,0 +1,117 @@
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<DICTIONARY type="multilanguage">
+  <!-- Control table -->
+  <ENTRY id="Control.Text.CustomizeDataPathDlg#Description">
+    <STRING lang="en" value="Do you want to store the blockchain, and other data, in a specific folder?"/>
+	<STRING lang="ru" value="Вы можете выбрать место хранения блокчейна и других данных."/>
+    <STRING lang="zh" value="你想把区块链数据存放在一个特定的文件夹吗？"/>
+    <STRING lang="zh_TW" value="你想把区块链数据存放在一个特定的文件夹吗？"/>
+  </ENTRY>
+  <ENTRY id="Control.Text.CustomizeDataPathDlg#Text">
+    <STRING lang="en" value="Select one of the options below, then click &quot;Next&quot;."/>
+	<STRING lang="ru" value="Выберите один из вариантов ниже, затем нажмите Далее"/>
+    <STRING lang="zh" value="请选择，然后“下一步”"/>
+    <STRING lang="zh_TW" value="请选择，然后“下一步”"/>
+  </ENTRY>
+  <ENTRY id="Control.Text.CustomizeDataPathDlg#Title">
+    <STRING lang="en" value="Choose Custom Data Storage Folder?"/>
+	<STRING lang="ru" value="Выберите место хранения данных."/>
+    <STRING lang="zh" value="选择数据保存的文件夹?"/>
+    <STRING lang="zh_TW" value="选择数据保存的文件夹?"/>
+  </ENTRY>
+  <ENTRY id="Control.Text.CustomizeDbDlg#Description">
+    <STRING lang="en" value="Do you want to store the blockchain, and other data, in a specific folder?"/>
+	<STRING lang="ru" value="Вы можете выбрать место хранения блокчейна и других данных."/>
+    <STRING lang="zh" value="Do you want to store the blockchain, and other data, in a specific folder?"/>
+    <STRING lang="zh_TW" value="Do you want to store the blockchain, and other data, in a specific folder?"/>
+  </ENTRY>
+  <ENTRY id="Control.Text.CustomizeDbDlg#Title">
+    <STRING lang="en" value="Choose Custom Data Storage Folder?"/>
+	<STRING lang="ru" value="Выберите место хранения данных."/>
+    <STRING lang="zh" value="Choose Custom Data Storage Folder?"/>
+    <STRING lang="zh_TW" value="Choose Custom Data Storage Folder?"/>
+  </ENTRY>
+  <ENTRY id="Control.Text.DataFolderDlg#Description">
+    <STRING lang="en" value="This is the folder where the blockchain, and other data, will be stored."/>
+	<STRING lang="ru" value="Это папка, в которой будет храниться блокчейн и другие данные."/>
+    <STRING lang="zh" value="这里是区块链及其它数据存放的文件夹"/>
+    <STRING lang="zh_TW" value="这里是区块链及其它数据存放的文件夹"/>
+  </ENTRY>
+  <ENTRY id="Control.Text.DataFolderDlg#Text">
+    <STRING lang="en" value="To store data in this folder, click &quot;[Text_Next]&quot;. To store data in a different folder, enter it below or click &quot;Browse&quot;."/>
+	<STRING lang="ru" value="Чтобы сохранить данные в этой папке, нажмите &quot;[Text_Next]&quot;. Чтобы сохранить данные в другой папке, введите ее ниже или нажмите &quot;Обзор&quot;."/>
+    <STRING lang="zh" value="如果存放在这个文件夹，点 “下一步”。如果存放在其它位置，请选择“浏览”。"/>
+    <STRING lang="zh_TW" value="如果存放在这个文件夹，点 “下一步”。如果存放在其它位置，请选择“浏览”。"/>
+  </ENTRY>
+  <ENTRY id="Control.Text.DataFolderDlg#Title">
+    <STRING lang="en" value="Select Data Storage Folder"/>
+	<STRING lang="ru" value="Выберите папку для хранения данных"/>
+    <STRING lang="zh" value="请选择文件存储地方"/>
+    <STRING lang="zh_TW" value="请选择文件存储地方"/>
+  </ENTRY>
+  <ENTRY id="Control.Text.DbFolderDlg#Description">
+    <STRING lang="en" value="This is the folder where the blockchain, and other data, will be stored."/>
+	<STRING lang="ru" value="Это папка, в которой будет храниться блокчейн и другие данные."/>
+    <STRING lang="zh" value="This is the folder where the blockchain, and other data, will be stored."/>
+    <STRING lang="zh_TW" value="This is the folder where the blockchain, and other data, will be stored."/>
+  </ENTRY>
+  <ENTRY id="Control.Text.DbFolderDlg#Title">
+    <STRING lang="en" value="Select Data Storage Folder"/>
+	<STRING lang="ru" value="Выберите папку для хранения данных"/>
+    <STRING lang="zh" value="请选择文件存储地方"/>
+    <STRING lang="zh_TW" value="请选择文件存储地方"/>
+  </ENTRY>
+  <ENTRY id="Control.Text.NTPDialog#Description">
+    <STRING lang="en" value="Reconfigure Windows for more accurate time?"/>
+	<STRING lang="ru" value="Настроить синхронизацию времени системы Windows?"/>
+    <STRING lang="zh" value="重新配置Windows以获得更准确的时间？"/>
+  </ENTRY>
+  <ENTRY id="Control.Text.NTPDialog#Text_1">
+    <STRING lang="en" value="An accurate Windows clock is required to connect to the [ProductName] network and make transactions."/>
+	<STRING lang="ru" value="Для подключения к сети Qortal и совершения транзакций требуется точная настройка времени Windows"/>
+    <STRING lang="zh" value="需要准确的Windows时钟才能连接到[ProductName]网络并进行交易。"/>
+  </ENTRY>
+  <ENTRY id="Control.Text.NTPDialog#Text_2">
+    <STRING lang="en" value="Select one of the options below, then click &quot;Next&quot;."/>
+	<STRING lang="ru" value="Выберите один из вариантов ниже, затем нажмите"/>
+    <STRING lang="zh" value="请选择，然后“下一步”"/>
+  </ENTRY>
+  <ENTRY id="Control.Text.NTPDialog#Text_3">
+    <STRING lang="en" value="Your computer&apos;s clock needs to be accurate to within 0.5 seconds."/>
+	<STRING lang="ru" value="Точность времени вашего компьютера должна составлять 0.5 секунд."/>
+    <STRING lang="zh" value="您的计算机时钟需要准确到0.5秒内。"/>
+  </ENTRY>
+  <ENTRY id="Control.Text.NTPDialog#Title">
+    <STRING lang="en" value="Windows clock accuracy"/>
+	<STRING lang="ru" value="Настройка времени системы Windows"/>
+    <STRING lang="zh" value="Windows 时钟精度"/>
+  </ENTRY>
+  <ENTRY id="Control.Text.VerifyRemoveDlg#RemoveBlockchainCheckbox">
+    <STRING lang="en" value="Remove downloaded blockchain and other data"/>
+	<STRING lang="ru" value="Удалить загруженный блокчейн и другие данные"/>
+    <STRING lang="zh" value="删除您下载的区块链"/>
+  </ENTRY>
+  <!-- RadioButton table -->
+  <ENTRY id="RadioButton.Text.CUSTOM_DB_BOOL#choose">
+    <STRING lang="en" value="Choose custom data storage folder..."/>
+	<STRING lang="ru" value="Выбрать папку для хранения данных..."/>
+    <STRING lang="zh" value="选择特定的文件夹存储"/>
+    <STRING lang="zh_TW" value="选择特定的文件夹存储"/>
+  </ENTRY>
+  <ENTRY id="RadioButton.Text.CUSTOM_DB_BOOL#default">
+    <STRING lang="en" value="Use default location "/>
+	<STRING lang="ru" value="Использовать папку по умолчанию"/>
+    <STRING lang="zh" value="使用默认存储地点"/>
+    <STRING lang="zh_TW" value="使用默认存储地点"/>
+  </ENTRY>
+  <ENTRY id="RadioButton.Text.RECONFIG_NTP#1">
+    <STRING lang="en" value="Yes, configure Windows to use internet time servers (Recommended)"/>
+	<STRING lang="ru" value="Да, настроить синхронизацию времени Windows (Рекомендуется)"/>
+    <STRING lang="zh" value="是，将Windows配置为使用多个Internet时间服务器 (推荐的)"/>
+  </ENTRY>
+  <ENTRY id="RadioButton.Text.RECONFIG_NTP#2">
+    <STRING lang="en" value="No, I will manage clock accuracy myself"/>
+	<STRING lang="ru" value="Нет, я сам буду управлять настройками часов"/>
+    <STRING lang="zh" value="不，我会自己管理时钟精度。"/>
+  </ENTRY>
+</DICTIONARY>

lib/org/ciyam/AT/1.3.7/AT-1.3.7.pom

@@ -3,7 +3,7 @@
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
   <modelVersion>4.0.0</modelVersion>
   <groupId>org.ciyam</groupId>
-  <artifactId>at</artifactId>
-  <version>1.0</version>
+  <artifactId>AT</artifactId>
+  <version>1.3.7</version>
   <description>POM was created from install:install-file</description>
 </project>

lib/org/ciyam/AT/1.3.8/AT-1.3.8.pom

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+  <modelVersion>4.0.0</modelVersion>
+  <groupId>org.ciyam</groupId>
+  <artifactId>AT</artifactId>
+  <version>1.3.8</version>
+  <description>POM was created from install:install-file</description>
+</project>

lib/org/ciyam/AT/maven-metadata-local.xml

@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<metadata>
+  <groupId>org.ciyam</groupId>
+  <artifactId>AT</artifactId>
+  <versioning>
+    <release>1.3.8</release>
+    <versions>
+      <version>1.3.4</version>
+      <version>1.3.5</version>
+      <version>1.3.6</version>
+      <version>1.3.7</version>
+      <version>1.3.8</version>
+    </versions>
+    <lastUpdated>20200925114415</lastUpdated>
+  </versioning>
+</metadata>

lib/org/ciyam/at/maven-metadata-local.xml

@@ -1,12 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<metadata>
-  <groupId>org.ciyam</groupId>
-  <artifactId>at</artifactId>
-  <versioning>
-    <release>1.0</release>
-    <versions>
-      <version>1.0</version>
-    </versions>
-    <lastUpdated>20181105100741</lastUpdated>
-  </versioning>
-</metadata>

lib/org/hsqldb/hsqldb/2.5.0-fixed/hsqldb-2.5.0-fixed.pom

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+  <modelVersion>4.0.0</modelVersion>
+  <groupId>org.hsqldb</groupId>
+  <artifactId>hsqldb</artifactId>
+  <version>2.5.0-fixed</version>
+  <description>POM was created from install:install-file</description>
+</project>

lib/org/hsqldb/hsqldb/maven-metadata-local.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<metadata>
+  <groupId>org.hsqldb</groupId>
+  <artifactId>hsqldb</artifactId>
+  <versioning>
+    <release>2.5.0-fixed</release>
+    <versions>
+      <version>2.5.0-fixed</version>
+    </versions>
+    <lastUpdated>20200318133132</lastUpdated>
+  </versioning>
+</metadata>

log4j2.properties

@@ -1,11 +1,15 @@
 rootLogger.level = info
-# On Windows, uncomment this:
-# property.dirname = ${sys:user.home}\\AppData\\Roaming\\qortal\\
+# On Windows, uncomment next line to set dirname:
+# property.dirname = ${sys:user.home}\\AppData\\Local\\qortal\\
 property.filename = ${sys:log4j2.filenameTemplate:-log.txt}
 
 rootLogger.appenderRef.console.ref = stdout
 rootLogger.appenderRef.rolling.ref = FILE
 
+# Suppress extraneous bitcoinj library output
+logger.bitcoinj.name = org.bitcoinj
+logger.bitcoinj.level = error
+
 # Override HSQLDB logging level to "warn" as too much is logged at "info"
 logger.hsqldb.name = hsqldb.db
 logger.hsqldb.level = warn

pom.xml

@@ -3,20 +3,22 @@
 	<modelVersion>4.0.0</modelVersion>
 	<groupId>org.qortal</groupId>
 	<artifactId>qortal</artifactId>
-	<version>1.0</version>
+	<version>1.4.3</version>
 	<packaging>jar</packaging>
 	<properties>
-		<bitcoin.version>0.15.4</bitcoin.version>
+		<skipTests>true</skipTests>
+		<altcoinj.version>bf9fb80</altcoinj.version>
+		<bitcoinj.version>0.15.6</bitcoinj.version>
 		<bouncycastle.version>1.64</bouncycastle.version>
 		<build.timestamp>${maven.build.timestamp}</build.timestamp>
+		<ciyam-at.version>1.3.8</ciyam-at.version>
 		<commons-net.version>3.6</commons-net.version>
 		<commons-text.version>1.8</commons-text.version>
 		<dagger.version>1.2.2</dagger.version>
 		<guava.version>28.1-jre</guava.version>
-		<hsqldb.version>2.5.0</hsqldb.version>
-		<hsqldb-sqltool.version>2.5.0</hsqldb-sqltool.version>
+		<hsqldb.version>2.5.1</hsqldb.version>
 		<jersey.version>2.29.1</jersey.version>
-		<jetty.version>9.4.22.v20191022</jetty.version>
+		<jetty.version>9.4.29.v20200521</jetty.version>
 		<log4j.version>2.12.1</log4j.version>
 		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
 		<slf4j.version>1.7.12</slf4j.version>
@@ -198,6 +200,10 @@
 							<pattern>org.qortal.api.model**</pattern>
 							<template>${project.build.sourceDirectory}/org/qortal/data/package-info.java</template>
 						</package>
+						<package>
+							<pattern>org.qortal.api.model.**</pattern>
+							<template>${project.build.sourceDirectory}/org/qortal/data/package-info.java</template>
+						</package>
 					</packages>
 					<outputDirectory>${project.build.directory}/generated-sources/package-info</outputDirectory>
 				</configuration>
@@ -257,6 +263,8 @@
 							<!-- Don't include original swagger-UI as we're including our own 
 								modified version -->
 							<exclude>org.webjars:swagger-ui</exclude>
+							<!-- Don't include JUnit as it's for testing only! -->
+							<exclude>junit:junit</exclude>
 						</excludes>
 					</artifactSet>
 					<filters>
@@ -310,6 +318,14 @@
 					</execution>
 				</executions>
 			</plugin>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-surefire-plugin</artifactId>
+				<version>2.22.2</version>
+				<configuration>
+					<skipTests>${skipTests}</skipTests>
+				</configuration>
+			</plugin>
 		</plugins>
 		<pluginManagement>
 			<plugins>
@@ -372,6 +388,11 @@
 			<name>project</name>
 			<url>file:${project.basedir}/lib</url>
 		</repository>
+		<!-- jitpack for build-on-demand of altcoinj -->
+		<repository>
+			<id>jitpack.io</id>
+			<url>https://jitpack.io</url>
+		</repository>
 	</repositories>
 	<dependencies>
 		<!-- https://mvnrepository.com/artifact/org.codehaus.mojo/build-helper-maven-plugin -->
@@ -379,12 +400,14 @@
 			<groupId>org.codehaus.mojo</groupId>
 			<artifactId>build-helper-maven-plugin</artifactId>
 			<version>3.0.0</version>
+			<scope>provided</scope><!-- needed for build, not for runtime -->
 		</dependency>
 		<!-- https://mvnrepository.com/artifact/com.github.bohnman/package-info-maven-plugin -->
 		<dependency>
 			<groupId>com.github.bohnman</groupId>
 			<artifactId>package-info-maven-plugin</artifactId>
 			<version>${package-info-maven-plugin.version}</version>
+			<scope>provided</scope><!-- needed for build, not for runtime -->
 		</dependency>
 		<!-- HSQLDB for repository -->
 		<dependency>
@@ -392,23 +415,23 @@
 			<artifactId>hsqldb</artifactId>
 			<version>${hsqldb.version}</version>
 		</dependency>
-		<dependency>
-			<groupId>org.hsqldb</groupId>
-			<artifactId>sqltool</artifactId>
-			<version>${hsqldb-sqltool.version}</version>
-			<scope>test</scope>
-		</dependency>
 		<!-- CIYAM AT (automated transactions) -->
 		<dependency>
 			<groupId>org.ciyam</groupId>
-			<artifactId>at</artifactId>
-			<version>1.0</version>
+			<artifactId>AT</artifactId>
+			<version>${ciyam-at.version}</version>
 		</dependency>
 		<!-- Bitcoin support -->
 		<dependency>
 			<groupId>org.bitcoinj</groupId>
 			<artifactId>bitcoinj-core</artifactId>
-			<version>${bitcoin.version}</version>
+			<version>${bitcoinj.version}</version>
+		</dependency>
+		<!-- For Litecoin, etc. support, requires bitcoinj -->
+		<dependency>
+			<groupId>com.github.jjos2372</groupId>
+			<artifactId>altcoinj</artifactId>
+			<version>${altcoinj.version}</version>
 		</dependency>
 		<!-- Utilities -->
 		<dependency>
@@ -446,6 +469,10 @@
 					<groupId>org.asynchttpclient</groupId>
 					<artifactId>async-http-client</artifactId>
 				</exclusion>
+				<exclusion>
+					<groupId>io.druid</groupId>
+					<artifactId>java-util</artifactId>
+				</exclusion>
 			</exclusions>
 		</dependency>
 		<!-- For NTP -->
@@ -499,6 +526,12 @@
 			<artifactId>mail</artifactId>
 			<version>1.5.0-b01</version>
 		</dependency>
+		<!-- Unicode homoglyph utilities -->
+		<dependency>
+			<groupId>net.codebox</groupId>
+			<artifactId>homoglyph</artifactId>
+			<version>1.2.0</version>
+		</dependency>
 		<!-- Jetty -->
 		<dependency>
 			<groupId>org.eclipse.jetty</groupId>
@@ -527,6 +560,12 @@
 			<artifactId>jetty-client</artifactId>
 			<version>${jetty.version}</version>
 		</dependency>
+		<!-- Websocket support -->
+		<dependency>
+			<groupId>org.eclipse.jetty.websocket</groupId>
+			<artifactId>javax-websocket-server-impl</artifactId>
+			<version>${jetty.version}</version>
+		</dependency>
 		<!-- Jersey -->
 		<dependency>
 			<groupId>org.glassfish.jersey.core</groupId>

run.sh

@@ -1,34 +0,0 @@
-#!/bin/sh
-
-# There's no need to run as root, so don't allow it, for security reasons
-if [ "$USER" = "root" ]; then
-	echo "Please su to non-root user before running"
-	exit
-fi
-
-# No qortal.jar but we have a Maven built one?
-# Be helpful and copy across to correct location
-if [ ! -e qortal.jar -a -f target/qortal*.jar ]; then
-	echo "Copying Maven-built Qortal JAR to correct pathname"
-	cp target/qortal*.jar qortal.jar
-fi
-
-# Limits Java JVM stack size and maximum heap usage.
-# Comment out for bigger systems, e.g. non-routers
-# or when API documentation is enabled
-# JVM_MEMORY_ARGS="-Xss256k -Xmx128m"
-
-# Although java.net.preferIPv4Stack is supposed to be false
-# by default in Java 11, on some platforms (e.g. FreeBSD 12),
-# it is overriden to be true by default. Hence we explicitly
-# set it to true to obtain desired behaviour.
-nohup nice -n 20 java \
-	-Djava.net.preferIPv4Stack=false \
-	-XX:NativeMemoryTracking=summary \
-	${JVM_MEMORY_ARGS} \
-	-jar qortal.jar \
-	1>run.log 2>&1 &
-
-# Save backgrounded process's PID
-echo $! > run.pid
-echo qortal running as pid $!

run.sh

@@ -0,0 +1 @@
+start.sh

src/main/java/org/hsqldb/jdbc/HSQLDBPool.java

@@ -21,18 +21,28 @@ public class HSQLDBPool extends JDBCPool {
 	public Connection tryConnection() throws SQLException {
 		for (int i = 0; i < states.length(); i++) {
 			if (states.compareAndSet(i, RefState.available, RefState.allocated)) {
-				return connections[i].getConnection();
+				JDBCPooledConnection pooledConnection = connections[i];
+
+				if (pooledConnection == null)
+					// Probably shutdown situation
+					return null;
+
+				return pooledConnection.getConnection();
 			}
 
 			if (states.compareAndSet(i, RefState.empty, RefState.allocated)) {
 				try {
-					JDBCPooledConnection connection = (JDBCPooledConnection) source.getPooledConnection();
+					JDBCPooledConnection pooledConnection = (JDBCPooledConnection) source.getPooledConnection();
 
-					connection.addConnectionEventListener(this);
-					connection.addStatementEventListener(this);
-					connections[i] = connection;
+					if (pooledConnection == null)
+						// Probably shutdown situation
+						return null;
 
-					return connections[i].getConnection();
+					pooledConnection.addConnectionEventListener(this);
+					pooledConnection.addStatementEventListener(this);
+					connections[i] = pooledConnection;
+
+					return pooledConnection.getConnection();
 				} catch (SQLException e) {
 					states.set(i, RefState.empty);
 				}

src/main/java/org/qortal/ApplyUpdate.java

@@ -35,9 +35,11 @@ public class ApplyUpdate {
 	private static final String JAR_FILENAME = AutoUpdate.JAR_FILENAME;
 	private static final String NEW_JAR_FILENAME = AutoUpdate.NEW_JAR_FILENAME;
 	private static final String WINDOWS_EXE_LAUNCHER = "qortal.exe";
+	private static final String JAVA_TOOL_OPTIONS_NAME = "JAVA_TOOL_OPTIONS";
+	private static final String JAVA_TOOL_OPTIONS_VALUE = "-XX:MaxRAMFraction=4";
 
-	private static final long CHECK_INTERVAL = 5 * 1000L; // ms
-	private static final int MAX_ATTEMPTS = 5;
+	private static final long CHECK_INTERVAL = 10 * 1000L; // ms
+	private static final int MAX_ATTEMPTS = 12;
 
 	public static void main(String[] args) {
 		Security.insertProviderAt(new BouncyCastleProvider(), 0);
@@ -65,17 +67,19 @@ public class ApplyUpdate {
 	}
 
 	private static boolean shutdownNode() {
-		String BASE_URI = "http://localhost:" + Settings.getInstance().getApiPort() + "/";
-		LOGGER.info(String.format("Shutting down node using API via %s", BASE_URI));
+		String baseUri = "http://localhost:" + Settings.getInstance().getApiPort() + "/";
+		LOGGER.info(() -> String.format("Shutting down node using API via %s", baseUri));
 
 		int attempt;
 		for (attempt = 0; attempt < MAX_ATTEMPTS; ++attempt) {
-			LOGGER.info(String.format("Attempt #%d out of %d to shutdown node", attempt + 1, MAX_ATTEMPTS));
-			String response = ApiRequest.perform(BASE_URI + "admin/stop", null);
+			final int attemptForLogging = attempt;
+			LOGGER.info(() -> String.format("Attempt #%d out of %d to shutdown node", attemptForLogging + 1, MAX_ATTEMPTS));
+			String response = ApiRequest.perform(baseUri + "admin/stop", null);
 			if (response == null)
-				break;
+				// No response - consider node shut down
+				return true;
 
-			LOGGER.info(String.format("Response from API: %s", response));
+			LOGGER.info(() -> String.format("Response from API: %s", response));
 
 			try {
 				Thread.sleep(CHECK_INTERVAL);
@@ -99,19 +103,20 @@ public class ApplyUpdate {
 		Path newJar = Paths.get(NEW_JAR_FILENAME);
 
 		if (!Files.exists(newJar)) {
-			LOGGER.warn(String.format("Replacement JAR '%s' not found?", newJar));
+			LOGGER.warn(() -> String.format("Replacement JAR '%s' not found?", newJar));
 			return;
 		}
 
 		int attempt;
 		for (attempt = 0; attempt < MAX_ATTEMPTS; ++attempt) {
-			LOGGER.info(String.format("Attempt #%d out of %d to replace JAR", attempt + 1, MAX_ATTEMPTS));
+			final int attemptForLogging = attempt;
+			LOGGER.info(() -> String.format("Attempt #%d out of %d to replace JAR", attemptForLogging + 1, MAX_ATTEMPTS));
 
 			try {
 				Files.copy(newJar, realJar, StandardCopyOption.REPLACE_EXISTING);
 				break;
 			} catch (IOException e) {
-				LOGGER.info(String.format("Unable to replace JAR: %s", e.getMessage()));
+				LOGGER.info(() -> String.format("Unable to replace JAR: %s", e.getMessage()));
 
 				// Try again
 			}
@@ -119,6 +124,7 @@ public class ApplyUpdate {
 			try {
 				Thread.sleep(CHECK_INTERVAL);
 			} catch (InterruptedException e) {
+				LOGGER.warn("Ignoring interrupt...");
 				// Doggedly retry
 			}
 		}
@@ -129,13 +135,13 @@ public class ApplyUpdate {
 
 	private static void restartNode(String[] args) {
 		String javaHome = System.getProperty("java.home");
-		LOGGER.info(String.format("Java home: %s", javaHome));
+		LOGGER.info(() -> String.format("Java home: %s", javaHome));
 
 		Path javaBinary = Paths.get(javaHome, "bin", "java");
-		LOGGER.info(String.format("Java binary: %s", javaBinary));
+		LOGGER.info(() -> String.format("Java binary: %s", javaBinary));
 
 		Path exeLauncher = Paths.get(WINDOWS_EXE_LAUNCHER);
-		LOGGER.info(String.format("Windows EXE launcher: %s", exeLauncher));
+		LOGGER.info(() -> String.format("Windows EXE launcher: %s", exeLauncher));
 
 		List<String> javaCmd;
 		if (Files.exists(exeLauncher)) {
@@ -156,9 +162,16 @@ public class ApplyUpdate {
 		}
 
 		try {
-			LOGGER.info(String.format("Restarting node with: %s", String.join(" ", javaCmd)));
+			LOGGER.info(() -> String.format("Restarting node with: %s", String.join(" ", javaCmd)));
 
-			new ProcessBuilder(javaCmd).start();
+			ProcessBuilder processBuilder = new ProcessBuilder(javaCmd);
+
+			if (Files.exists(exeLauncher)) {
+				LOGGER.info(() -> String.format("Setting env %s to %s", JAVA_TOOL_OPTIONS_NAME, JAVA_TOOL_OPTIONS_VALUE));
+				processBuilder.environment().put(JAVA_TOOL_OPTIONS_NAME, JAVA_TOOL_OPTIONS_VALUE);
+			}
+
+			processBuilder.start();
 		} catch (IOException e) {
 			LOGGER.error(String.format("Failed to restart node (BAD): %s", e.getMessage()));
 		}

src/main/java/org/qortal/RepositoryMaintenance.java

@@ -0,0 +1,75 @@
+package org.qortal;
+
+import java.security.Security;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.bouncycastle.jce.provider.BouncyCastleProvider;
+import org.bouncycastle.jsse.provider.BouncyCastleJsseProvider;
+import org.qortal.controller.Controller;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.repository.RepositoryFactory;
+import org.qortal.repository.RepositoryManager;
+import org.qortal.repository.hsqldb.HSQLDBRepositoryFactory;
+import org.qortal.settings.Settings;
+
+public class RepositoryMaintenance {
+
+	static {
+		// This must go before any calls to LogManager/Logger
+		System.setProperty("java.util.logging.manager", "org.apache.logging.log4j.jul.LogManager");
+	}
+
+	private static final Logger LOGGER = LogManager.getLogger(RepositoryMaintenance.class);
+
+	public static void main(String[] args) {
+		LOGGER.info("Repository maintenance starting up...");
+
+		Security.insertProviderAt(new BouncyCastleProvider(), 0);
+		Security.insertProviderAt(new BouncyCastleJsseProvider(), 1);
+
+		// Load/check settings, which potentially sets up blockchain config, etc.
+		try {
+			if (args.length > 0)
+				Settings.fileInstance(args[0]);
+			else
+				Settings.getInstance();
+		} catch (Throwable t) {
+			LOGGER.error("Settings file error: " + t.getMessage());
+			System.exit(2);
+		}
+
+		LOGGER.info("Opening repository");
+		try {
+			RepositoryFactory repositoryFactory = new HSQLDBRepositoryFactory(Controller.getRepositoryUrl());
+			RepositoryManager.setRepositoryFactory(repositoryFactory);
+		} 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?");
+			} else {
+				LOGGER.error("Unable to start repository", e);
+			}
+
+			System.exit(1);
+		}
+
+		LOGGER.info("Starting repository periodic maintenance. This can take a while...");
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			repository.performPeriodicMaintenance();
+
+			LOGGER.info("Repository periodic maintenance completed");
+		} catch (DataException e) {
+			LOGGER.error("Repository periodic maintenance failed", e);
+		}
+
+		try {
+			LOGGER.info("Shutting down repository");
+			RepositoryManager.closeRepositoryFactory();
+		} catch (DataException e) {
+			LOGGER.error("Error occurred while shutting down repository", e);
+		}
+	}
+
+}

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

@@ -1,7 +1,9 @@
 package org.qortal.account;
 
-import java.math.BigDecimal;
-import java.util.List;
+import static org.qortal.utils.Amounts.prettyAmount;
+
+import javax.xml.bind.annotation.XmlAccessType;
+import javax.xml.bind.annotation.XmlAccessorType;
 
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
@@ -9,12 +11,11 @@ import org.qortal.block.BlockChain;
 import org.qortal.data.account.AccountBalanceData;
 import org.qortal.data.account.AccountData;
 import org.qortal.data.account.RewardShareData;
-import org.qortal.data.transaction.TransactionData;
 import org.qortal.repository.DataException;
 import org.qortal.repository.Repository;
-import org.qortal.transaction.Transaction;
 import org.qortal.utils.Base58;
 
+@XmlAccessorType(XmlAccessType.NONE) // Stops JAX-RS errors when unmarshalling blockchain config
 public class Account {
 
 	private static final Logger LOGGER = LogManager.getLogger(Account.class);
@@ -51,39 +52,52 @@ public class Account {
 		return new AccountData(this.address);
 	}
 
+	public void ensureAccount() throws DataException {
+		this.repository.getAccountRepository().ensureAccount(this.buildAccountData());
+	}
+
 	// Balance manipulations - assetId is 0 for QORT
 
-	public BigDecimal getBalance(long assetId, int height) throws DataException {
-		AccountBalanceData accountBalanceData = this.repository.getAccountRepository().getBalance(this.address, assetId, height);
-		if (accountBalanceData == null)
-			return BigDecimal.ZERO.setScale(8);
-
-		return accountBalanceData.getBalance();
-	}
-
-	public BigDecimal getConfirmedBalance(long assetId) throws DataException {
+	public long getConfirmedBalance(long assetId) throws DataException {
 		AccountBalanceData accountBalanceData = this.repository.getAccountRepository().getBalance(this.address, assetId);
 		if (accountBalanceData == null)
-			return BigDecimal.ZERO.setScale(8);
+			return 0;
 
 		return accountBalanceData.getBalance();
 	}
 
-	public void setConfirmedBalance(long assetId, BigDecimal balance) throws DataException {
+	public void setConfirmedBalance(long assetId, long balance) throws DataException {
 		// Safety feature!
-		if (balance.compareTo(BigDecimal.ZERO) < 0) {
-			String message = String.format("Refusing to set negative balance %s [assetId %d] for %s", balance.toPlainString(), assetId, this.address);
+		if (balance < 0) {
+			String message = String.format("Refusing to set negative balance %s [assetId %d] for %s", prettyAmount(balance), assetId, this.address);
 			LOGGER.error(message);
 			throw new DataException(message);
 		}
 
+		// Delete account balance record instead of setting balance to zero
+		if (balance == 0) {
+			this.repository.getAccountRepository().delete(this.address, assetId);
+			return;
+		}
+
 		// Can't have a balance without an account - make sure it exists!
-		this.repository.getAccountRepository().ensureAccount(this.buildAccountData());
+		this.ensureAccount();
 
 		AccountBalanceData accountBalanceData = new AccountBalanceData(this.address, assetId, balance);
 		this.repository.getAccountRepository().save(accountBalanceData);
 
-		LOGGER.trace(() -> String.format("%s balance now %s [assetId %s]", this.address, balance.toPlainString(), assetId));
+		LOGGER.trace(() -> String.format("%s balance now %s [assetId %s]", this.address, prettyAmount(balance), assetId));
+	}
+
+	// Convenience method
+	public void modifyAssetBalance(long assetId, long deltaBalance) throws DataException {
+		this.repository.getAccountRepository().modifyAssetBalance(this.getAddress(), assetId, deltaBalance);
+
+		LOGGER.trace(() -> String.format("%s balance %s by %s [assetId %s]",
+				this.address,
+				(deltaBalance >= 0 ? "increased" : "decreased"),
+				prettyAmount(Math.abs(deltaBalance)),
+				assetId));
 	}
 
 	public void deleteBalance(long assetId) throws DataException {
@@ -99,38 +113,11 @@ public class Account {
 	 * @throws DataException
 	 */
 	public byte[] getLastReference() throws DataException {
-		byte[] reference = this.repository.getAccountRepository().getLastReference(this.address);
+		byte[] reference = AccountRefCache.getLastReference(this.repository, this.address);
 		LOGGER.trace(() -> String.format("Last reference for %s is %s", this.address, reference == null ? "null" : Base58.encode(reference)));
 		return reference;
 	}
 
-	/**
-	 * Fetch last reference for account, considering unconfirmed transactions only, or return null.
-	 * <p>
-	 * NOTE: calls Transaction.getUnconfirmedTransactions which discards uncommitted
-	 * repository changes.
-	 * 
-	 * @return byte[] reference, or null if no unconfirmed transactions for this account.
-	 * @throws DataException
-	 */
-	public byte[] getUnconfirmedLastReference() throws DataException {
-		// Newest unconfirmed transaction takes priority
-		List<TransactionData> unconfirmedTransactions = Transaction.getUnconfirmedTransactions(repository);
-
-		byte[] reference = null;
-
-		for (TransactionData transactionData : unconfirmedTransactions) {
-			String unconfirmedTransactionAddress = PublicKeyAccount.getAddress(transactionData.getCreatorPublicKey());
-
-			if (unconfirmedTransactionAddress.equals(this.address))
-				reference = transactionData.getSignature();
-		}
-
-		final byte[] loggingReference = reference;
-		LOGGER.trace(() -> String.format("Last unconfirmed reference for %s is %s", this.address, loggingReference == null ? "null" : Base58.encode(loggingReference)));
-		return reference;
-	}
-
 	/**
 	 * Set last reference for account.
 	 * 
@@ -143,7 +130,7 @@ public class Account {
 
 		AccountData accountData = this.buildAccountData();
 		accountData.setReference(reference);
-		this.repository.getAccountRepository().setLastReference(accountData);
+		AccountRefCache.setLastReference(this.repository, accountData);
 	}
 
 	// Default groupID manipulations
@@ -204,11 +191,15 @@ public class Account {
 	 * @throws DataException
 	 */
 	public boolean canMint() throws DataException {
-		Integer level = this.getLevel();
+		AccountData accountData = this.repository.getAccountRepository().getAccount(this.address);
+		if (accountData == null)
+			return false;
+
+		Integer level = accountData.getLevel();
 		if (level != null && level >= BlockChain.getInstance().getMinAccountLevelToMint())
 			return true;
 
-		if (this.isFounder())
+		if (Account.isFounder(accountData.getFlags()))
 			return true;
 
 		return false;
@@ -226,11 +217,15 @@ public class Account {
 	 * @throws DataException
 	 */
 	public boolean canRewardShare() throws DataException {
-		Integer level = this.getLevel();
+		AccountData accountData = this.repository.getAccountRepository().getAccount(this.address);
+		if (accountData == null)
+			return false;
+
+		Integer level = accountData.getLevel();
 		if (level != null && level >= BlockChain.getInstance().getMinAccountLevelToRewardShare())
 			return true;
 
-		if (this.isFounder())
+		if (Account.isFounder(accountData.getFlags()))
 			return true;
 
 		return false;
@@ -264,14 +259,14 @@ public class Account {
 	 * @throws DataException
 	 */
 	public int getEffectiveMintingLevel() throws DataException {
-		if (this.isFounder())
-			return BlockChain.getInstance().getFounderEffectiveMintingLevel();
-
-		Integer level = this.getLevel();
-		if (level == null)
+		AccountData accountData = this.repository.getAccountRepository().getAccount(this.address);
+		if (accountData == null)
 			return 0;
 
-		return level;
+		if (Account.isFounder(accountData.getFlags()))
+			return BlockChain.getInstance().getFounderEffectiveMintingLevel();
+
+		return accountData.getLevel();
 	}
 
 	/**
@@ -290,7 +285,7 @@ public class Account {
 		if (rewardShareData == null)
 			return 0;
 
-		PublicKeyAccount rewardShareMinter = new PublicKeyAccount(repository, rewardShareData.getMinterPublicKey());
+		Account rewardShareMinter = new Account(repository, rewardShareData.getMinter());
 		return rewardShareMinter.getEffectiveMintingLevel();
 	}
 

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

@@ -0,0 +1,217 @@
+package org.qortal.account;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.function.BinaryOperator;
+
+import org.qortal.data.account.AccountData;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.utils.Pair;
+
+/**
+ * Account lastReference caching
+ * <p>
+ * When checking an account's lastReference, the value returned should be the
+ * most recent value set after processing the most recent block.
+ * <p>
+ * However, when processing a batch of transactions, e.g. during block processing or validation,
+ * each transaction needs to check, and maybe update, multiple accounts' lastReference values.
+ * <p>
+ * Because the intermediate updates would affect future checks, we set up a cache of that
+ * maintains a consistent value for fetching lastReference, but also tracks the latest new
+ * value, without the overhead of repository calls.
+ * <p>
+ * Thus, when batch transaction processing is finished, only the latest new lastReference values
+ * can be committed to the repository, via {@link AccountRefCache#commit()}.
+ * <p>
+ * Getting and setting lastReferences values are done the usual way via
+ * {@link Account#getLastReference()} and {@link Account#setLastReference(byte[])} which call
+ * package-visibility methods in <tt>AccountRefCache</tt>.
+ * <p>
+ * If {@link Account#getLastReference()} or {@link Account#setLastReference(byte[])} are called
+ * outside of caching then lastReference values are fetched/set directly from/to the repository.
+ * <p>
+ * <tt>AccountRefCache</tt> implements <tt>AutoCloseable</tt> for (typical) use in a try-with-resources block.
+ *
+ * @see Account#getLastReference()
+ * @see Account#setLastReference(byte[])
+ * @see org.qortal.block.Block#process()
+ */
+public class AccountRefCache implements AutoCloseable {
+
+	private static final Map<Repository, RefCache> CACHE = new HashMap<>();
+
+	private static class RefCache {
+		private final Map<String, byte[]> getLastReferenceValues = new HashMap<>();
+		private final Map<String, Pair<byte[], byte[]>> setLastReferenceValues = new HashMap<>();
+
+		/**
+		 * Function for merging publicKey from new data with old publicKey from map.
+		 * <p>
+		 * Last reference is <tt>A</tt> element in pair.<br>
+		 * Public key is <tt>B</tt> element in pair.
+		 */
+		private static final BinaryOperator<Pair<byte[], byte[]>> mergePublicKey = (oldPair,  newPair) -> {
+			// If passed new pair contains non-null publicKey, then we use that one in preference.
+			if (newPair.getB() == null)
+				// Otherwise, inherit publicKey from old map value.
+				newPair.setB(oldPair.getB());
+
+			// We always use new lastReference from new pair.
+			return newPair;
+		};
+
+
+		public byte[] getLastReference(Repository repository, String address) throws DataException {
+			synchronized (this.getLastReferenceValues) {
+				byte[] lastReference = getLastReferenceValues.get(address);
+				if (lastReference != null)
+					// address is present in map, lastReference not null
+					return lastReference;
+
+				// address is present in map, just lastReference is null
+				if (getLastReferenceValues.containsKey(address))
+					return null;
+
+				lastReference = repository.getAccountRepository().getLastReference(address);
+				this.getLastReferenceValues.put(address, lastReference);
+				return lastReference;
+			}
+		}
+
+		public void setLastReference(AccountData accountData) {
+			// We're only interested in lastReference and publicKey
+			Pair<byte[], byte[]> newPair = new Pair<>(accountData.getReference(), accountData.getPublicKey());
+
+			synchronized (this.setLastReferenceValues) {
+				setLastReferenceValues.merge(accountData.getAddress(), newPair, mergePublicKey);
+			}
+		}
+
+		Map<String, Pair<byte[], byte[]>> getNewLastReferences() {
+			return setLastReferenceValues;
+		}
+	}
+
+	private Repository repository;
+
+	/**
+	 * Constructs a new account reference cache, unique to passed <tt>repository</tt> handle.
+	 * 
+	 * @param repository
+	 * @throws IllegalStateException if a cache already exists for <tt>repository</tt>
+	 */
+	public AccountRefCache(Repository repository) {
+		RefCache refCache = new RefCache();
+
+		synchronized (CACHE) {
+			if (CACHE.putIfAbsent(repository, refCache) != null)
+				throw new IllegalStateException("Account reference cache entry already exists");
+		}
+
+		this.repository = repository;
+	}
+
+	/**
+	 * Save all cached setLastReference account-reference values into repository.
+	 * <p>
+	 * Closes cache to prevent any future setLastReference() attempts post-commit.
+	 * 
+	 * @throws DataException
+	 */
+	public void commit() throws DataException {
+		RefCache refCache;
+
+		// Also duplicated in close(), this prevents future setLastReference() attempts post-commit.
+		synchronized (CACHE) {
+			refCache = CACHE.remove(this.repository);
+		}
+
+		if (refCache == null)
+			throw new IllegalStateException("Tried to commit non-existent account reference cache");
+
+		Map<String, Pair<byte[], byte[]>> newLastReferenceValues = refCache.getNewLastReferences();
+
+		for (Entry<String, Pair<byte[], byte[]>> entry : newLastReferenceValues.entrySet()) {
+			AccountData accountData = new AccountData(entry.getKey());
+
+			accountData.setReference(entry.getValue().getA());
+
+			if (entry.getValue().getB() != null)
+				accountData.setPublicKey(entry.getValue().getB());
+
+			this.repository.getAccountRepository().setLastReference(accountData);
+		}
+	}
+
+	@Override
+	public void close() {
+		synchronized (CACHE) {
+			CACHE.remove(this.repository);
+		}
+	}
+
+	/**
+	 * Returns lastReference value for account.
+	 * <p>
+	 * If cache is not in effect for passed <tt>repository</tt> handle,
+	 * then this method fetches lastReference directly from repository.
+	 * <p>
+	 * If cache <i>is</i> in effect, then this method returns cached
+	 * lastReference, which is <b>not</b> affected by calls to
+	 * <tt>setLastReference</tt>.
+	 * <p>
+	 * Typically called by corresponding method in Account class.
+	 * 
+	 * @param repository
+	 * @param address account's address
+	 * @return account's lastReference, or null if account unknown, or lastReference not set
+	 * @throws DataException
+	 */
+	/*package*/ static byte[] getLastReference(Repository repository, String address) throws DataException {
+		RefCache refCache;
+
+		synchronized (CACHE) {
+			refCache = CACHE.get(repository);
+		}
+
+		if (refCache == null)
+			return repository.getAccountRepository().getLastReference(address);
+
+		return refCache.getLastReference(repository, address);
+	}
+
+	/**
+	 * Sets lastReference value for account.
+	 * <p>
+	 * If cache is not in effect for passed <tt>repository</tt> handle,
+	 * then this method sets lastReference directly in repository.
+	 * <p>
+	 * If cache <i>is</i> in effect, then this method caches the new
+	 * lastReference, which is <b>not</b> returned by calls to
+	 * <tt>getLastReference</tt>.
+	 * <p>
+	 * Typically called by corresponding method in Account class.
+	 * 
+	 * @param repository
+	 * @param accountData
+	 * @throws DataException
+	 */
+	/*package*/ static void setLastReference(Repository repository, AccountData accountData) throws DataException {
+		RefCache refCache;
+
+		synchronized (CACHE) {
+			refCache = CACHE.get(repository);
+		}
+
+		if (refCache == null) {
+			repository.getAccountRepository().setLastReference(accountData);
+			return;
+		}
+
+		refCache.setLastReference(accountData);
+	}
+
+}

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

@@ -1,13 +0,0 @@
-package org.qortal.account;
-
-import org.qortal.repository.Repository;
-
-public final class GenesisAccount extends PublicKeyAccount {
-
-	public static final byte[] PUBLIC_KEY = new byte[] { 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
-
-	public GenesisAccount(Repository repository) {
-		super(repository, PUBLIC_KEY);
-	}
-
-}

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

@@ -0,0 +1,24 @@
+package org.qortal.account;
+
+import org.qortal.crypto.Crypto;
+import org.qortal.repository.Repository;
+
+public final class NullAccount extends PublicKeyAccount {
+
+	public static final byte[] PUBLIC_KEY = new byte[32];
+	public static final String ADDRESS = Crypto.toAddress(PUBLIC_KEY);
+
+	public NullAccount(Repository repository) {
+		super(repository, PUBLIC_KEY, ADDRESS);
+	}
+
+	protected NullAccount() {
+	}
+
+	@Override
+	public boolean verify(byte[] signature, byte[] message) {
+		// Can't sign, hence can't verify.
+		return false;
+	}
+
+}

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

@@ -2,18 +2,11 @@ package org.qortal.account;
 
 import org.bouncycastle.crypto.params.Ed25519PrivateKeyParameters;
 import org.bouncycastle.crypto.params.Ed25519PublicKeyParameters;
-import org.bouncycastle.crypto.params.X25519PrivateKeyParameters;
-import org.bouncycastle.crypto.params.X25519PublicKeyParameters;
-import org.bouncycastle.math.ec.rfc8032.Ed25519;
-import org.qortal.crypto.BouncyCastle25519;
 import org.qortal.crypto.Crypto;
 import org.qortal.repository.Repository;
 
 public class PrivateKeyAccount extends PublicKeyAccount {
 
-	private static final int SIGNATURE_LENGTH = 64;
-	private static final int SHARED_SECRET_LENGTH = 32;
-
 	private final byte[] privateKey;
 	private final Ed25519PrivateKeyParameters edPrivateKeyParams;
 
@@ -49,24 +42,11 @@ public class PrivateKeyAccount extends PublicKeyAccount {
 	}
 
 	public byte[] sign(byte[] message) {
-		byte[] signature = new byte[SIGNATURE_LENGTH];
-
-		this.edPrivateKeyParams.sign(Ed25519.Algorithm.Ed25519, edPublicKeyParams, null, message, 0, message.length, signature, 0);
-
-		return signature;
+		return Crypto.sign(this.edPrivateKeyParams, message);
 	}
 
 	public byte[] getSharedSecret(byte[] publicKey) {
-		byte[] x25519PrivateKey = BouncyCastle25519.toX25519PrivateKey(this.privateKey);
-		X25519PrivateKeyParameters xPrivateKeyParams = new X25519PrivateKeyParameters(x25519PrivateKey, 0);
-
-		byte[] x25519PublicKey = BouncyCastle25519.toX25519PublicKey(publicKey);
-		X25519PublicKeyParameters xPublicKeyParams = new X25519PublicKeyParameters(x25519PublicKey, 0);
-
-		byte[] sharedSecret = new byte[SHARED_SECRET_LENGTH];
-		xPrivateKeyParams.generateSecret(xPublicKeyParams, sharedSecret, 0);
-
-		return sharedSecret;
+		return Crypto.getSharedSecret(this.privateKey, publicKey);
 	}
 
 	public byte[] getRewardSharePrivateKey(byte[] publicKey) {

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

@@ -1,7 +1,6 @@
 package org.qortal.account;
 
 import org.bouncycastle.crypto.params.Ed25519PublicKeyParameters;
-import org.bouncycastle.math.ec.rfc8032.Ed25519;
 import org.qortal.crypto.Crypto;
 import org.qortal.data.account.AccountData;
 import org.qortal.repository.Repository;
@@ -22,6 +21,18 @@ public class PublicKeyAccount extends Account {
 		this.publicKey = edPublicKeyParams.getEncoded();
 	}
 
+	protected PublicKeyAccount(Repository repository, byte[] publicKey, String address) {
+		super(repository, address);
+
+		this.publicKey = publicKey;
+		this.edPublicKeyParams = null;
+	}
+
+	protected PublicKeyAccount() {
+		this.publicKey = null;
+		this.edPublicKeyParams = null;
+	}
+
 	public byte[] getPublicKey() {
 		return this.publicKey;
 	}
@@ -34,15 +45,7 @@ public class PublicKeyAccount extends Account {
 	}
 
 	public boolean verify(byte[] signature, byte[] message) {
-		return PublicKeyAccount.verify(this.publicKey, signature, message);
-	}
-
-	public static boolean verify(byte[] publicKey, byte[] signature, byte[] message) {
-		try {
-			return Ed25519.verify(signature, 0, publicKey, 0, message, 0, message.length);
-		} catch (Exception e) {
-			return false;
-		}
+		return Crypto.verify(this.publicKey, signature, message);
 	}
 
 	public static String getAddress(byte[] publicKey) {

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

@@ -0,0 +1,27 @@
+package org.qortal.api;
+
+import java.math.BigDecimal;
+
+import javax.xml.bind.annotation.adapters.XmlAdapter;
+
+import org.qortal.utils.Amounts;
+
+public class AmountTypeAdapter extends XmlAdapter<String, Long> {
+
+	@Override
+	public Long unmarshal(String input) throws Exception {
+		if (input == null)
+			return null;
+
+		return new BigDecimal(input).setScale(8).unscaledValue().longValue();
+	}
+
+	@Override
+	public String marshal(Long output) throws Exception {
+		if (output == null)
+			return null;
+
+		return Amounts.prettyAmount(output);
+	}
+
+}

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

@@ -5,16 +5,23 @@ import static java.util.stream.Collectors.toMap;
 
 import java.util.Map;
 
+import javax.xml.bind.annotation.XmlAccessType;
+import javax.xml.bind.annotation.XmlAccessorType;
+import javax.xml.bind.annotation.XmlRootElement;
+
+@XmlAccessorType(XmlAccessType.NONE)
+@XmlRootElement
 public enum ApiError {
 	// COMMON
 	// UNKNOWN(0, 500),
 	JSON(1, 400),
-	// NO_BALANCE(2, 422),
+	INSUFFICIENT_BALANCE(2, 402),
 	// NOT_YET_RELEASED(3, 422),
 	UNAUTHORIZED(4, 403),
 	REPOSITORY_ISSUE(5, 500),
 	NON_PRODUCTION(6, 403),
 	BLOCKCHAIN_NEEDS_SYNC(7, 503),
+	NO_TIME_SYNC(8, 503),
 
 	// VALIDATION
 	INVALID_SIGNATURE(101, 400),
@@ -117,7 +124,12 @@ public enum ApiError {
 	// MESSAGESIZE_EXCEEDED(1004, 400),
 
 	// Groups
-	GROUP_UNKNOWN(1101, 404);
+	GROUP_UNKNOWN(1101, 404),
+
+	// Foreign blockchain
+	FOREIGN_BLOCKCHAIN_NETWORK_ISSUE(1201, 500),
+	FOREIGN_BLOCKCHAIN_BALANCE_ISSUE(1202, 402),
+	FOREIGN_BLOCKCHAIN_TOO_SOON(1203, 408);
 
 	private static final Map<Integer, ApiError> map = stream(ApiError.values()).collect(toMap(apiError -> apiError.code, apiError -> apiError));
 

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

@@ -3,6 +3,7 @@ package org.qortal.api;
 import java.io.IOException;
 
 import javax.servlet.RequestDispatcher;
+import javax.servlet.ServletException;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
@@ -17,7 +18,7 @@ public class ApiErrorHandler extends ErrorHandler {
 	private static final Logger LOGGER = LogManager.getLogger(ApiErrorHandler.class);
 
 	@Override
-	public void handle(String target, Request baseRequest, HttpServletRequest request, HttpServletResponse response) throws IOException {
+	public void handle(String target, Request baseRequest, HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException {
 		if (Settings.getInstance().isApiLoggingEnabled()) {
 			String requestURI = request.getRequestURI();
 

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

@@ -0,0 +1,20 @@
+package org.qortal.api;
+
+import javax.xml.bind.annotation.XmlElement;
+import javax.xml.bind.annotation.adapters.XmlJavaTypeAdapter;
+
+public class ApiErrorRoot {
+
+	private ApiError apiError;
+
+	@XmlJavaTypeAdapter(ApiErrorTypeAdapter.class)
+	@XmlElement(name = "error")
+	public ApiError getApiError() {
+		return this.apiError;
+	}
+
+	public void setApiError(ApiError apiError) {
+		this.apiError = apiError;
+	}
+
+}

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

@@ -0,0 +1,32 @@
+package org.qortal.api;
+
+import javax.xml.bind.annotation.adapters.XmlAdapter;
+
+public class ApiErrorTypeAdapter extends XmlAdapter<ApiErrorTypeAdapter.AdaptedApiError, ApiError> {
+
+	public static class AdaptedApiError {
+		public int code;
+		public String description;
+	}
+
+	@Override
+	public ApiError unmarshal(AdaptedApiError adaptedInput) throws Exception {
+		if (adaptedInput == null)
+			return null;
+
+		return ApiError.fromCode(adaptedInput.code);
+	}
+
+	@Override
+	public AdaptedApiError marshal(ApiError output) throws Exception {
+		if (output == null)
+			return null;
+
+		AdaptedApiError adaptedOutput = new AdaptedApiError();
+		adaptedOutput.code = output.getCode();
+		adaptedOutput.description = output.name();
+
+		return adaptedOutput;
+	}
+
+}

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

@@ -149,8 +149,8 @@ public class ApiRequest {
 		HttpURLConnection con = (HttpURLConnection) url.openConnection();
 
 		con.setRequestMethod("GET");
-		con.setConnectTimeout(5000);
-		con.setReadTimeout(3000);
+		con.setConnectTimeout(30000);
+		con.setReadTimeout(10000);
 		ApiRequest.setConnectionSSL(con, ipAddress);
 
 		int status = con.getResponseCode();

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

@@ -2,15 +2,31 @@ package org.qortal.api;
 
 import io.swagger.v3.jaxrs2.integration.resources.OpenApiResource;
 
+import java.io.InputStream;
 import java.net.InetAddress;
 import java.net.InetSocketAddress;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.security.KeyStore;
+import java.security.SecureRandom;
 
+import javax.net.ssl.KeyManagerFactory;
+import javax.net.ssl.SSLContext;
+
+import org.eclipse.jetty.http.HttpVersion;
 import org.eclipse.jetty.rewrite.handler.RedirectPatternRule;
 import org.eclipse.jetty.rewrite.handler.RewriteHandler;
 import org.eclipse.jetty.server.CustomRequestLog;
+import org.eclipse.jetty.server.DetectorConnectionFactory;
+import org.eclipse.jetty.server.HttpConfiguration;
+import org.eclipse.jetty.server.HttpConnectionFactory;
 import org.eclipse.jetty.server.RequestLog;
 import org.eclipse.jetty.server.RequestLogWriter;
+import org.eclipse.jetty.server.SecureRequestCustomizer;
 import org.eclipse.jetty.server.Server;
+import org.eclipse.jetty.server.ServerConnector;
+import org.eclipse.jetty.server.SslConnectionFactory;
 import org.eclipse.jetty.server.handler.ErrorHandler;
 import org.eclipse.jetty.server.handler.InetAccessHandler;
 import org.eclipse.jetty.servlet.DefaultServlet;
@@ -18,10 +34,18 @@ import org.eclipse.jetty.servlet.FilterHolder;
 import org.eclipse.jetty.servlet.ServletContextHandler;
 import org.eclipse.jetty.servlet.ServletHolder;
 import org.eclipse.jetty.servlets.CrossOriginFilter;
+import org.eclipse.jetty.util.ssl.SslContextFactory;
 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.api.websocket.ActiveChatsWebSocket;
+import org.qortal.api.websocket.AdminStatusWebSocket;
+import org.qortal.api.websocket.BlocksWebSocket;
+import org.qortal.api.websocket.ChatMessagesWebSocket;
+import org.qortal.api.websocket.PresenceWebSocket;
+import org.qortal.api.websocket.TradeBotWebSocket;
+import org.qortal.api.websocket.TradeOffersWebSocket;
 import org.qortal.settings.Settings;
 
 public class ApiService {
@@ -53,9 +77,57 @@ public class ApiService {
 	public void start() {
 		try {
 			// Create API server
-			InetAddress bindAddr = InetAddress.getByName(Settings.getInstance().getBindAddress());
-			InetSocketAddress endpoint = new InetSocketAddress(bindAddr, Settings.getInstance().getApiPort());
-			this.server = new Server(endpoint);
+
+			// SSL support if requested
+			String keystorePathname = Settings.getInstance().getSslKeystorePathname();
+			String keystorePassword = Settings.getInstance().getSslKeystorePassword();
+
+			if (keystorePathname != null && keystorePassword != null) {
+				// SSL version
+				if (!Files.isReadable(Path.of(keystorePathname)))
+					throw new RuntimeException("Failed to start SSL API due to broken keystore");
+
+				// BouncyCastle-specific SSLContext build
+				SSLContext sslContext = SSLContext.getInstance("TLS", "BCJSSE");
+				KeyManagerFactory keyManagerFactory = KeyManagerFactory.getInstance("PKIX", "BCJSSE");
+
+				KeyStore keyStore = KeyStore.getInstance(KeyStore.getDefaultType(), "BC");
+
+				try (InputStream keystoreStream = Files.newInputStream(Paths.get(keystorePathname))) {
+					keyStore.load(keystoreStream, keystorePassword.toCharArray());
+				}
+
+				keyManagerFactory.init(keyStore, keystorePassword.toCharArray());
+				sslContext.init(keyManagerFactory.getKeyManagers(), null, new SecureRandom());
+
+				SslContextFactory.Server sslContextFactory = new SslContextFactory.Server();
+				sslContextFactory.setSslContext(sslContext);
+
+				this.server = new Server();
+
+				HttpConfiguration httpConfig = new HttpConfiguration();
+				httpConfig.setSecureScheme("https");
+				httpConfig.setSecurePort(Settings.getInstance().getApiPort());
+
+				SecureRequestCustomizer src = new SecureRequestCustomizer();
+				httpConfig.addCustomizer(src);
+
+				HttpConnectionFactory httpConnectionFactory = new HttpConnectionFactory(httpConfig);
+				SslConnectionFactory sslConnectionFactory = new SslConnectionFactory(sslContextFactory, HttpVersion.HTTP_1_1.asString());
+
+				ServerConnector portUnifiedConnector = new ServerConnector(this.server,
+						new DetectorConnectionFactory(sslConnectionFactory),
+						httpConnectionFactory);
+				portUnifiedConnector.setHost(Settings.getInstance().getBindAddress());
+				portUnifiedConnector.setPort(Settings.getInstance().getApiPort());
+
+				this.server.addConnector(portUnifiedConnector);
+			} else {
+				// Non-SSL
+				InetAddress bindAddr = InetAddress.getByName(Settings.getInstance().getBindAddress());
+				InetSocketAddress endpoint = new InetSocketAddress(bindAddr, Settings.getInstance().getApiPort());
+				this.server = new Server(endpoint);
+			}
 
 			// Error handler
 			ErrorHandler errorHandler = new ApiErrorHandler();
@@ -108,10 +180,29 @@ public class ApiService {
 				swaggerUIServlet.setInitParameter("pathInfoOnly", "true");
 				context.addServlet(swaggerUIServlet, "/api-documentation/*");
 
-				rewriteHandler.addRule(new RedirectPatternRule("", "/api-documentation/")); // redirect to Swagger UI start page
-				rewriteHandler.addRule(new RedirectPatternRule("/api-documentation", "/api-documentation/")); // redirect to Swagger UI start page
+				rewriteHandler.addRule(new RedirectPatternRule("", "/api-documentation/")); // redirect empty path to API docs
+				rewriteHandler.addRule(new RedirectPatternRule("/api-documentation", "/api-documentation/")); // redirect to add trailing slash if missing
+			} else {
+				// Simple pages that explains that API documentation is disabled
+				ClassLoader loader = this.getClass().getClassLoader();
+				ServletHolder swaggerUIServlet = new ServletHolder("api-docs-disabled", DefaultServlet.class);
+				swaggerUIServlet.setInitParameter("resourceBase", loader.getResource("api-docs-disabled/").toString());
+				swaggerUIServlet.setInitParameter("dirAllowed", "true");
+				swaggerUIServlet.setInitParameter("pathInfoOnly", "true");
+				context.addServlet(swaggerUIServlet, "/api-documentation/*");
+
+				rewriteHandler.addRule(new RedirectPatternRule("", "/api-documentation/")); // redirect empty path to API docs
+				rewriteHandler.addRule(new RedirectPatternRule("/api-documentation", "/api-documentation/")); // redirect to add trailing slash if missing
 			}
 
+			context.addServlet(AdminStatusWebSocket.class, "/websockets/admin/status");
+			context.addServlet(BlocksWebSocket.class, "/websockets/blocks");
+			context.addServlet(ActiveChatsWebSocket.class, "/websockets/chat/active/*");
+			context.addServlet(ChatMessagesWebSocket.class, "/websockets/chat/messages");
+			context.addServlet(TradeOffersWebSocket.class, "/websockets/crosschain/tradeoffers");
+			context.addServlet(TradeBotWebSocket.class, "/websockets/crosschain/tradebot");
+			context.addServlet(PresenceWebSocket.class, "/websockets/presence");
+
 			// Start server
 			this.server.start();
 		} catch (Exception e) {

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

@@ -0,0 +1,25 @@
+package org.qortal.api;
+
+import java.math.BigDecimal;
+
+import javax.xml.bind.annotation.adapters.XmlAdapter;
+
+public class RewardSharePercentTypeAdapter extends XmlAdapter<String, Integer> {
+
+	@Override
+	public Integer unmarshal(String input) throws Exception {
+		if (input == null)
+			return null;
+
+		return new BigDecimal(input).setScale(2).unscaledValue().intValue();
+	}
+
+	@Override
+	public String marshal(Integer output) throws Exception {
+		if (output == null)
+			return null;
+
+		return String.format("%d.%02d", output / 100, Math.abs(output % 100));
+	}
+
+}

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

@@ -5,10 +5,20 @@ import java.net.UnknownHostException;
 
 import javax.servlet.http.HttpServletRequest;
 
-public class Security {
+import org.qortal.settings.Settings;
+
+public abstract class Security {
+
+	public static final String API_KEY_HEADER = "X-API-KEY";
 
-	// TODO: replace with proper authentication
 	public static void checkApiCallAllowed(HttpServletRequest request) {
+		String expectedApiKey = Settings.getInstance().getApiKey();
+		String passedApiKey = request.getHeader(API_KEY_HEADER);
+
+		if ((expectedApiKey != null && !expectedApiKey.equals(passedApiKey)) ||
+				(passedApiKey != null && !passedApiKey.equals(expectedApiKey)))
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.UNAUTHORIZED);
+
 		InetAddress remoteAddr;
 		try {
 			remoteAddr = InetAddress.getByName(request.getRemoteAddr());
@@ -19,4 +29,5 @@ public class Security {
 		if (!remoteAddr.isLoopbackAddress())
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.UNAUTHORIZED);
 	}
+
 }

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

@@ -1,5 +1,6 @@
 package org.qortal.api.model;
 
+import java.util.Collections;
 import java.util.EnumMap;
 import java.util.Map;
 
@@ -13,17 +14,61 @@ import org.qortal.transaction.Transaction.TransactionType;
 @XmlAccessorType(XmlAccessType.FIELD)
 public class ActivitySummary {
 
-	public int blockCount;
-	public int transactionCount;
-	public int assetsIssued;
-	public int namesRegistered;
+	private int blockCount;
+	private int assetsIssued;
+	private int namesRegistered;
 
 	// Assuming TransactionType values are contiguous so 'length' equals count
 	@XmlJavaTypeAdapter(TransactionCountMapXmlAdapter.class)
-	public Map<TransactionType, Integer> transactionCountByType = new EnumMap<>(TransactionType.class);
+	private Map<TransactionType, Integer> transactionCountByType = new EnumMap<>(TransactionType.class);
+	private int totalTransactionCount = 0;
 
 	public ActivitySummary() {
 		// Needed for JAXB
 	}
 
+	public int getBlockCount() {
+		return this.blockCount;
+	}
+
+	public void setBlockCount(int blockCount) {
+		this.blockCount = blockCount;
+	}
+
+	public int getTotalTransactionCount() {
+		return this.totalTransactionCount;
+	}
+
+	public int getAssetsIssued() {
+		return this.assetsIssued;
+	}
+
+	public void setAssetsIssued(int assetsIssued) {
+		this.assetsIssued = assetsIssued;
+	}
+
+	public int getNamesRegistered() {
+		return this.namesRegistered;
+	}
+
+	public void setNamesRegistered(int namesRegistered) {
+		this.namesRegistered = namesRegistered;
+	}
+
+	public Map<TransactionType, Integer> getTransactionCountByType() {
+		return Collections.unmodifiableMap(this.transactionCountByType);
+	}
+
+	public void setTransactionCountByType(TransactionType transactionType, int transactionCount) {
+		this.transactionCountByType.put(transactionType, transactionCount);
+
+		this.totalTransactionCount = this.transactionCountByType.values().stream().mapToInt(Integer::intValue).sum();
+	}
+
+	public void setTransactionCountByType(Map<TransactionType, Integer> transactionCountByType) {
+		this.transactionCountByType = new EnumMap<>(transactionCountByType);
+
+		this.totalTransactionCount = this.transactionCountByType.values().stream().mapToInt(Integer::intValue).sum();
+	}
+
 }

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

@@ -1,11 +1,10 @@
 package org.qortal.api.model;
 
-import java.math.BigDecimal;
-
 import javax.xml.bind.Marshaller;
 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.data.asset.OrderData;
 
@@ -29,12 +28,14 @@ public class AggregatedOrder {
 	}
 
 	@XmlElement(name = "price")
-	public BigDecimal getPrice() {
+	@XmlJavaTypeAdapter(value = org.qortal.api.AmountTypeAdapter.class)
+	public long getPrice() {
 		return this.orderData.getPrice();
 	}
 
 	@XmlElement(name = "unfulfilled")
-	public BigDecimal getUnfulfilled() {
+	@XmlJavaTypeAdapter(value = org.qortal.api.AmountTypeAdapter.class)
+	public long getUnfulfilled() {
 		return this.orderData.getAmount();
 	}
 

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

@@ -6,7 +6,7 @@ import javax.xml.bind.annotation.XmlAccessorType;
 import org.qortal.crypto.Crypto;
 
 @XmlAccessorType(XmlAccessType.FIELD)
-public class BlockMinterSummary {
+public class BlockSignerSummary {
 
 	// Properties
 
@@ -20,22 +20,25 @@ public class BlockMinterSummary {
 
 	// Constructors
 
-	protected BlockMinterSummary() {
+	protected BlockSignerSummary() {
 	}
 
-	/** Constructs BlockMinterSummary in non-reward-share context. */
-	public BlockMinterSummary(byte[] blockMinterPublicKey, int blockCount) {
+	/** Constructs BlockSignerSummary in non-reward-share context. */
+	public BlockSignerSummary(byte[] blockMinterPublicKey, int blockCount) {
 		this.blockCount = blockCount;
 
 		this.mintingAccountPublicKey = blockMinterPublicKey;
 		this.mintingAccount = Crypto.toAddress(this.mintingAccountPublicKey);
 	}
 
-	/** Constructs BlockMinterSummary in reward-share context. */
-	public BlockMinterSummary(byte[] rewardSharePublicKey, int blockCount, byte[] mintingAccountPublicKey, String recipientAccount) {
-		this(mintingAccountPublicKey, blockCount);
-
+	/** Constructs BlockSignerSummary in reward-share context. */
+	public BlockSignerSummary(byte[] rewardSharePublicKey, int blockCount, byte[] mintingAccountPublicKey, String minterAccount, String recipientAccount) {
 		this.rewardSharePublicKey = rewardSharePublicKey;
+		this.blockCount = blockCount;
+
+		this.mintingAccountPublicKey = mintingAccountPublicKey;
+		this.mintingAccount = minterAccount;
+
 		this.recipientAccount = recipientAccount;
 	}
 

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

@@ -25,7 +25,8 @@ public class ConnectedPeer {
 
 	public String address;
 	public String version;
-	public Long buildTimestamp;
+
+	public String nodeId;
 
 	public Integer lastHeight;
 	@Schema(example = "base58")
@@ -45,10 +46,9 @@ public class ConnectedPeer {
 		this.peersConnectedWhen = peer.getPeersConnectionTimestamp();
 
 		this.address = peerData.getAddress().toString();
-		if (peer.getVersionMessage() != null) {
-			this.version = peer.getVersionMessage().getVersionString();
-			this.buildTimestamp = peer.getVersionMessage().getBuildTimestamp();
-		}
+
+		this.version = peer.getPeersVersionString();
+		this.nodeId = peer.getPeersNodeId();
 
 		PeerChainTipData peerChainTipData = peer.getChainTipData();
 		if (peerChainTipData != null) {

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

@@ -0,0 +1,34 @@
+package org.qortal.api.model;
+
+import java.math.BigDecimal;
+
+import javax.xml.bind.annotation.XmlAccessType;
+import javax.xml.bind.annotation.XmlAccessorType;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+
+@XmlAccessorType(XmlAccessType.FIELD)
+public class CrossChainBitcoinRedeemRequest {
+
+	@Schema(description = "Bitcoin HASH160(public key) for refund", example = "2nGDBPPPFS1c9w1h33YwFk4KUJU2")
+	public byte[] refundPublicKeyHash;
+
+	@Schema(description = "Bitcoin PRIVATE KEY for redeem", example = "cUvGNSnu14q6Hr1X7TESjYVTqBpFjj8GGLGjGdpJwD9NhSQKeYUk")
+	public byte[] redeemPrivateKey;
+
+	@Schema(description = "Qortal AT address")
+	public String atAddress;
+
+	@Schema(description = "Bitcoin miner fee", example = "0.00001000")
+	public BigDecimal bitcoinMinerFee;
+
+	@Schema(description = "32-byte secret", example = "6gVbAXCVzJXAWwtAVGAfgAkkXpeXvPUwSciPmCfSfXJG")
+	public byte[] secret;
+
+	@Schema(description = "Bitcoin HASH160(public key) for receiving funds, or omit to derive from private key", example = "u17kBVKkKSp12oUzaxFwNnq1JZf")
+	public byte[] receivingAccountInfo;
+
+	public CrossChainBitcoinRedeemRequest() {
+	}
+
+}

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

@@ -0,0 +1,31 @@
+package org.qortal.api.model;
+
+import java.math.BigDecimal;
+
+import javax.xml.bind.annotation.XmlAccessType;
+import javax.xml.bind.annotation.XmlAccessorType;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+
+@XmlAccessorType(XmlAccessType.FIELD)
+public class CrossChainBitcoinRefundRequest {
+
+	@Schema(description = "Bitcoin PRIVATE KEY for refund", example = "cSP3zTb6bfm8GATtAcEJ8LqYtNQmzZ9jE2wQUVnZGiBzojDdrwKV")
+	public byte[] refundPrivateKey;
+
+	@Schema(description = "Bitcoin HASH160(public key) for redeem", example = "2daMveGc5pdjRyFacbxBzMksCbyC")
+	public byte[] redeemPublicKeyHash;
+
+	@Schema(description = "Qortal AT address")
+	public String atAddress;
+
+	@Schema(description = "Bitcoin miner fee", example = "0.00001000")
+	public BigDecimal bitcoinMinerFee;
+
+	@Schema(description = "Bitcoin HASH160(public key) for receiving funds, or omit to derive from private key", example = "u17kBVKkKSp12oUzaxFwNnq1JZf")
+	public byte[] receivingAccountInfo;
+
+	public CrossChainBitcoinRefundRequest() {
+	}
+
+}

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

@@ -0,0 +1,23 @@
+package org.qortal.api.model;
+
+import javax.xml.bind.annotation.XmlAccessType;
+import javax.xml.bind.annotation.XmlAccessorType;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+
+@XmlAccessorType(XmlAccessType.FIELD)
+public class CrossChainBitcoinTemplateRequest {
+
+	@Schema(description = "Bitcoin HASH160(public key) for refund", example = "2nGDBPPPFS1c9w1h33YwFk4KUJU2")
+	public byte[] refundPublicKeyHash;
+
+	@Schema(description = "Bitcoin HASH160(public key) for redeem", example = "2daMveGc5pdjRyFacbxBzMksCbyC")
+	public byte[] redeemPublicKeyHash;
+
+	@Schema(description = "Qortal AT address")
+	public String atAddress;
+
+	public CrossChainBitcoinTemplateRequest() {
+	}
+
+}

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

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

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

@@ -0,0 +1,39 @@
+package org.qortal.api.model;
+
+import javax.xml.bind.annotation.XmlAccessType;
+import javax.xml.bind.annotation.XmlAccessorType;
+import javax.xml.bind.annotation.adapters.XmlJavaTypeAdapter;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+
+@XmlAccessorType(XmlAccessType.FIELD)
+public class CrossChainBuildRequest {
+
+	@Schema(description = "AT creator's public key", example = "C6wuddsBV3HzRrXUtezE7P5MoRXp5m3mEDokRDGZB6ry")
+	public byte[] creatorPublicKey;
+
+	@Schema(description = "Final QORT amount paid out on successful trade", example = "80.40200000")
+	@XmlJavaTypeAdapter(value = org.qortal.api.AmountTypeAdapter.class)
+	public long qortAmount;
+
+	@Schema(description = "QORT amount funding AT, including covering AT execution fees", example = "123.45670000")
+	@XmlJavaTypeAdapter(value = org.qortal.api.AmountTypeAdapter.class)
+	public long fundingQortAmount;
+
+	@Schema(description = "HASH160 of creator's Bitcoin public key", example = "2daMveGc5pdjRyFacbxBzMksCbyC")
+	public byte[] bitcoinPublicKeyHash;
+
+	@Schema(description = "HASH160 of secret", example = "43vnftqkjxrhb5kJdkU1ZFQLEnWV")
+	public byte[] hashOfSecretB;
+
+	@Schema(description = "Bitcoin P2SH BTC balance for release of secret", example = "0.00864200")
+	@XmlJavaTypeAdapter(value = org.qortal.api.AmountTypeAdapter.class)
+	public long bitcoinAmount;
+
+	@Schema(description = "Trade time window (minutes) from trade agreement to automatic refund", example = "10080")
+	public Integer tradeTimeout;
+
+	public CrossChainBuildRequest() {
+	}
+
+}

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

@@ -0,0 +1,20 @@
+package org.qortal.api.model;
+
+import javax.xml.bind.annotation.XmlAccessType;
+import javax.xml.bind.annotation.XmlAccessorType;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+
+@XmlAccessorType(XmlAccessType.FIELD)
+public class CrossChainCancelRequest {
+
+	@Schema(description = "AT creator's public key", example = "K6wuddsBV3HzRrXFFezE7P5MoRXp5m3mEDokRDGZB6ry")
+	public byte[] creatorPublicKey;
+
+	@Schema(description = "Qortal trade AT address")
+	public String atAddress;
+
+	public CrossChainCancelRequest() {
+	}
+
+}

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

@@ -0,0 +1,127 @@
+package org.qortal.api.model;
+
+import javax.xml.bind.annotation.XmlAccessType;
+import javax.xml.bind.annotation.XmlAccessorType;
+import javax.xml.bind.annotation.adapters.XmlJavaTypeAdapter;
+
+import org.qortal.crosschain.AcctMode;
+import org.qortal.data.crosschain.CrossChainTradeData;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+
+// All properties to be converted to JSON via JAXB
+@XmlAccessorType(XmlAccessType.FIELD)
+public class CrossChainOfferSummary {
+
+	// Properties
+
+	@Schema(description = "AT's Qortal address")
+	private String qortalAtAddress;
+
+	@Schema(description = "AT creator's Qortal address")
+	private String qortalCreator;
+
+	@Schema(description = "AT creator's ephemeral trading key-pair represented as Qortal address")
+	private String qortalCreatorTradeAddress;
+
+	@XmlJavaTypeAdapter(value = org.qortal.api.AmountTypeAdapter.class)
+	private long qortAmount;
+
+	@Schema(description = "Bitcoin amount - DEPRECATED: use foreignAmount")
+	@XmlJavaTypeAdapter(value = org.qortal.api.AmountTypeAdapter.class)
+	@Deprecated
+	private long btcAmount;
+
+	@Schema(description = "Foreign blockchain amount")
+	@XmlJavaTypeAdapter(value = org.qortal.api.AmountTypeAdapter.class)
+	private long foreignAmount;
+
+	@Schema(description = "Suggested trade timeout (minutes)", example = "10080")
+	private int tradeTimeout;
+
+	@Schema(description = "Current AT execution mode")
+	private AcctMode mode;
+
+	private long timestamp;
+
+	@Schema(description = "Trade partner's Qortal receiving address")
+	private String partnerQortalReceivingAddress;
+
+	private String foreignBlockchain;
+
+	private String acctName;
+
+	protected CrossChainOfferSummary() {
+		/* For JAXB */
+	}
+
+	public CrossChainOfferSummary(CrossChainTradeData crossChainTradeData, long timestamp) {
+		this.qortalAtAddress = crossChainTradeData.qortalAtAddress;
+		this.qortalCreator = crossChainTradeData.qortalCreator;
+		this.qortalCreatorTradeAddress = crossChainTradeData.qortalCreatorTradeAddress;
+		this.qortAmount = crossChainTradeData.qortAmount;
+		this.foreignAmount = crossChainTradeData.expectedForeignAmount;
+		this.btcAmount = this.foreignAmount; // Duplicate for deprecated field
+		this.tradeTimeout = crossChainTradeData.tradeTimeout;
+		this.mode = crossChainTradeData.mode;
+		this.timestamp = timestamp;
+		this.partnerQortalReceivingAddress = crossChainTradeData.qortalPartnerReceivingAddress;
+		this.foreignBlockchain = crossChainTradeData.foreignBlockchain;
+		this.acctName = crossChainTradeData.acctName;
+	}
+
+	public String getQortalAtAddress() {
+		return this.qortalAtAddress;
+	}
+
+	public String getQortalCreator() {
+		return this.qortalCreator;
+	}
+
+	public String getQortalCreatorTradeAddress() {
+		return this.qortalCreatorTradeAddress;
+	}
+
+	public long getQortAmount() {
+		return this.qortAmount;
+	}
+
+	public long getBtcAmount() {
+		return this.btcAmount;
+	}
+
+	public long getForeignAmount() {
+		return this.foreignAmount;
+	}
+
+	public int getTradeTimeout() {
+		return this.tradeTimeout;
+	}
+
+	public AcctMode getMode() {
+		return this.mode;
+	}
+
+	public long getTimestamp() {
+		return this.timestamp;
+	}
+
+	public String getPartnerQortalReceivingAddress() {
+		return this.partnerQortalReceivingAddress;
+	}
+
+	public String getForeignBlockchain() {
+		return this.foreignBlockchain;
+	}
+
+	public String getAcctName() {
+		return this.acctName;
+	}
+
+	// For debugging mostly
+
+	public String toString() {
+		return String.format("%s: %s", this.qortalAtAddress, this.mode);
+	}
+
+}

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

@@ -0,0 +1,29 @@
+package org.qortal.api.model;
+
+import javax.xml.bind.annotation.XmlAccessType;
+import javax.xml.bind.annotation.XmlAccessorType;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+
+@XmlAccessorType(XmlAccessType.FIELD)
+public class CrossChainSecretRequest {
+
+	@Schema(description = "Public key to match AT's trade 'partner'", example = "C6wuddsBV3HzRrXUtezE7P5MoRXp5m3mEDokRDGZB6ry")
+	public byte[] partnerPublicKey;
+
+	@Schema(description = "Qortal AT address")
+	public String atAddress;
+
+	@Schema(description = "secret-A (32 bytes)", example = "FHMzten4he9jZ4HGb4297Utj6F5g2w7serjq2EnAg2s1")
+	public byte[] secretA;
+
+	@Schema(description = "secret-B (32 bytes)", example = "EN2Bgx3BcEMtxFCewmCVSMkfZjVKYhx3KEXC5A21KBGx")
+	public byte[] secretB;
+
+	@Schema(description = "Qortal address for receiving QORT from AT")
+	public String receivingAddress;
+
+	public CrossChainSecretRequest() {
+	}
+
+}

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

@@ -0,0 +1,23 @@
+package org.qortal.api.model;
+
+import javax.xml.bind.annotation.XmlAccessType;
+import javax.xml.bind.annotation.XmlAccessorType;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+
+@XmlAccessorType(XmlAccessType.FIELD)
+public class CrossChainTradeRequest {
+
+	@Schema(description = "AT creator's 'trade' public key", example = "C6wuddsBV3HzRrXUtezE7P5MoRXp5m3mEDokRDGZB6ry")
+	public byte[] tradePublicKey;
+
+	@Schema(description = "Qortal AT address")
+	public String atAddress;
+
+	@Schema(description = "Signature of trading partner's 'offer' MESSAGE transaction")
+	public byte[] messageTransactionSignature;
+
+	public CrossChainTradeRequest() {
+	}
+
+}

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

@@ -0,0 +1,54 @@
+package org.qortal.api.model;
+
+import javax.xml.bind.annotation.XmlAccessType;
+import javax.xml.bind.annotation.XmlAccessorType;
+import javax.xml.bind.annotation.adapters.XmlJavaTypeAdapter;
+
+import org.qortal.data.crosschain.CrossChainTradeData;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+
+// All properties to be converted to JSON via JAXB
+@XmlAccessorType(XmlAccessType.FIELD)
+public class CrossChainTradeSummary {
+
+	private long tradeTimestamp;
+
+	@XmlJavaTypeAdapter(value = org.qortal.api.AmountTypeAdapter.class)
+	private long qortAmount;
+
+	@Deprecated
+	@Schema(description = "DEPRECATED: use foreignAmount instead")
+	@XmlJavaTypeAdapter(value = org.qortal.api.AmountTypeAdapter.class)
+	private long btcAmount;
+
+	@XmlJavaTypeAdapter(value = org.qortal.api.AmountTypeAdapter.class)
+	private long foreignAmount;
+
+	protected CrossChainTradeSummary() {
+		/* For JAXB */
+	}
+
+	public CrossChainTradeSummary(CrossChainTradeData crossChainTradeData, long timestamp) {
+		this.tradeTimestamp = timestamp;
+		this.qortAmount = crossChainTradeData.qortAmount;
+		this.foreignAmount = crossChainTradeData.expectedForeignAmount;
+		this.btcAmount = this.foreignAmount;
+	}
+
+	public long getTradeTimestamp() {
+		return this.tradeTimestamp;
+	}
+
+	public long getQortAmount() {
+		return this.qortAmount;
+	}
+
+	public long getBtcAmount() {
+		return this.btcAmount;
+	}
+
+	public long getForeignAmount() {
+		return this.foreignAmount;
+	}
+}

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

@@ -10,6 +10,8 @@ public class NodeInfo {
 	public long uptime;
 	public String buildVersion;
 	public long buildTimestamp;
+	public String nodeId;
+	public boolean isTestNet;
 
 	public NodeInfo() {
 	}

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

@@ -0,0 +1,33 @@
+package org.qortal.api.model;
+
+import javax.xml.bind.annotation.XmlAccessType;
+import javax.xml.bind.annotation.XmlAccessorType;
+
+import org.qortal.controller.Controller;
+import org.qortal.network.Network;
+
+@XmlAccessorType(XmlAccessType.FIELD)
+public class NodeStatus {
+
+	public final boolean isMintingPossible;
+	public final boolean isSynchronizing;
+
+	// Not always present
+	public final Integer syncPercent;
+
+	public final int numberOfConnections;
+
+	public final int height;
+
+	public NodeStatus() {
+		this.isMintingPossible = Controller.getInstance().isMintingPossible();
+
+		this.syncPercent = Controller.getInstance().getSyncPercent();
+		this.isSynchronizing = this.syncPercent != null;
+
+		this.numberOfConnections = Network.getInstance().getHandshakedPeers().size();
+
+		this.height = Controller.getInstance().getChainHeight();
+	}
+
+}

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

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

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

@@ -0,0 +1,29 @@
+package org.qortal.api.model.crosschain;
+
+import javax.xml.bind.annotation.XmlAccessType;
+import javax.xml.bind.annotation.XmlAccessorType;
+import javax.xml.bind.annotation.adapters.XmlJavaTypeAdapter;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+
+@XmlAccessorType(XmlAccessType.FIELD)
+public class BitcoinSendRequest {
+
+	@Schema(description = "Bitcoin BIP32 extended private key", example = "tprv___________________________________________________________________________________________________________")
+	public String xprv58;
+
+	@Schema(description = "Recipient's Bitcoin address ('legacy' P2PKH only)", example = "1BitcoinEaterAddressDontSendf59kuE")
+	public String receivingAddress;
+
+	@Schema(description = "Amount of BTC to send", type = "number")
+	@XmlJavaTypeAdapter(value = org.qortal.api.AmountTypeAdapter.class)
+	public long bitcoinAmount;
+
+	@Schema(description = "Transaction fee per byte (optional). Default is 0.00000100 BTC (100 sats) per byte", example = "0.00000100", type = "number")
+	@XmlJavaTypeAdapter(value = org.qortal.api.AmountTypeAdapter.class)
+	public Long feePerByte;
+
+	public BitcoinSendRequest() {
+	}
+
+}

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

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

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

@@ -0,0 +1,46 @@
+package org.qortal.api.model.crosschain;
+
+import javax.xml.bind.annotation.XmlAccessType;
+import javax.xml.bind.annotation.XmlAccessorType;
+import javax.xml.bind.annotation.adapters.XmlJavaTypeAdapter;
+
+import org.qortal.crosschain.SupportedBlockchain;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+
+@XmlAccessorType(XmlAccessType.FIELD)
+public class TradeBotCreateRequest {
+
+	@Schema(description = "Trade creator's public key", example = "2zR1WFsbM7akHghqSCYKBPk6LDP8aKiQSRS1FrwoLvoB")
+	public byte[] creatorPublicKey;
+
+	@Schema(description = "QORT amount paid out on successful trade", example = "80.40000000", type = "number")
+	@XmlJavaTypeAdapter(value = org.qortal.api.AmountTypeAdapter.class)
+	public long qortAmount;
+
+	@Schema(description = "QORT amount funding AT, including covering AT execution fees", example = "80.50000000", type = "number")
+	@XmlJavaTypeAdapter(value = org.qortal.api.AmountTypeAdapter.class)
+	public long fundingQortAmount;
+
+	@Deprecated
+	@Schema(description = "Bitcoin amount wanted in return. DEPRECATED: use foreignAmount instead", example = "0.00864200", type = "number", hidden = true)
+	@XmlJavaTypeAdapter(value = org.qortal.api.AmountTypeAdapter.class)
+	public Long bitcoinAmount;
+
+	@Schema(description = "Foreign blockchain. Note: default (BITCOIN) to be removed in the future", example = "BITCOIN", implementation = SupportedBlockchain.class)
+	public SupportedBlockchain foreignBlockchain;
+
+	@Schema(description = "Foreign blockchain amount wanted in return", example = "0.00864200", type = "number")
+	@XmlJavaTypeAdapter(value = org.qortal.api.AmountTypeAdapter.class)
+	public Long foreignAmount;
+
+	@Schema(description = "Suggested trade timeout (minutes)", example = "10080")
+	public int tradeTimeout;
+
+	@Schema(description = "Foreign blockchain address for receiving", example = "1BitcoinEaterAddressDontSendf59kuE")
+	public String receivingAddress;
+
+	public TradeBotCreateRequest() {
+	}
+
+}

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

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

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

@@ -7,6 +7,7 @@ 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.security.SecurityRequirement;
 import io.swagger.v3.oas.annotations.tags.Tag;
 
 import java.math.BigDecimal;
@@ -28,6 +29,7 @@ import org.qortal.api.ApiError;
 import org.qortal.api.ApiErrors;
 import org.qortal.api.ApiException;
 import org.qortal.api.ApiExceptionFactory;
+import org.qortal.api.Security;
 import org.qortal.api.model.ApiOnlineAccount;
 import org.qortal.api.model.RewardShareKeyRequest;
 import org.qortal.asset.Asset;
@@ -36,18 +38,27 @@ import org.qortal.crypto.Crypto;
 import org.qortal.data.account.AccountData;
 import org.qortal.data.account.RewardShareData;
 import org.qortal.data.network.OnlineAccountData;
+import org.qortal.data.transaction.PublicizeTransactionData;
 import org.qortal.data.transaction.RewardShareTransactionData;
+import org.qortal.data.transaction.TransactionData;
 import org.qortal.repository.DataException;
 import org.qortal.repository.Repository;
 import org.qortal.repository.RepositoryManager;
 import org.qortal.settings.Settings;
+import org.qortal.transaction.PublicizeTransaction;
 import org.qortal.transaction.Transaction;
+import org.qortal.transaction.Transaction.TransactionType;
 import org.qortal.transaction.Transaction.ValidationResult;
 import org.qortal.transform.TransformationException;
 import org.qortal.transform.Transformer;
+import org.qortal.transform.transaction.PublicizeTransactionTransformer;
 import org.qortal.transform.transaction.RewardShareTransactionTransformer;
+import org.qortal.transform.transaction.TransactionTransformer;
+import org.qortal.utils.Amounts;
 import org.qortal.utils.Base58;
 
+import com.google.common.primitives.Bytes;
+
 @Path("/addresses")
 @Tag(name = "Addresses")
 public class AddressesResource {
@@ -66,32 +77,18 @@ public class AddressesResource {
 			)
 		}
 	)
-	@ApiErrors({ApiError.INVALID_ADDRESS, ApiError.REPOSITORY_ISSUE})
+	@ApiErrors({ApiError.INVALID_ADDRESS, ApiError.ADDRESS_UNKNOWN, ApiError.REPOSITORY_ISSUE})
 	public AccountData getAccountInfo(@PathParam("address") String address) {
 		if (!Crypto.isValidAddress(address))
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_ADDRESS);
 
 		try (final Repository repository = RepositoryManager.getRepository()) {
 			AccountData accountData = repository.getAccountRepository().getAccount(address);
-
 			// Not found?
 			if (accountData == null)
-				accountData = new AccountData(address);
-			else {
-				// Unconfirmed transactions could update lastReference
-				Account account = new Account(repository, address);
-
-				// Use last reference based on unconfirmed transactions if possible
-				byte[] unconfirmedLastReference = account.getUnconfirmedLastReference();
-
-				if (unconfirmedLastReference != null)
-					// There are unconfirmed transactions so modify returned data
-					accountData.setReference(unconfirmedLastReference);
-			}
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.ADDRESS_UNKNOWN);
 
 			return accountData;
-		} catch (ApiException e) {
-			throw e;
 		} catch (DataException e) {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
 		}
@@ -100,42 +97,37 @@ public class AddressesResource {
 	@GET
 	@Path("/lastreference/{address}")
 	@Operation(
-		summary = "Fetch reference for next transaction to be created by address, considering unconfirmed transactions",
-		description = "Returns the base58-encoded signature of the last confirmed/unconfirmed transaction created by address, failing that: the first incoming transaction. Returns \"false\" if there is no transactions.",
+		summary = "Fetch reference for next transaction to be created by address",
+		description = "Returns the base58-encoded signature of the last confirmed transaction created by address, failing that: the first incoming transaction. Returns \"false\" if there is no last-reference.",
 		responses = {
 			@ApiResponse(
-				description = "the base58-encoded transaction signature",
+				description = "the base58-encoded last-reference",
 				content = @Content(mediaType = MediaType.TEXT_PLAIN, schema = @Schema(type = "string"))
 			)
 		}
 	)
-	@ApiErrors({ApiError.INVALID_ADDRESS, ApiError.REPOSITORY_ISSUE})
-	public String getLastReferenceUnconfirmed(@PathParam("address") String address) {
+	@ApiErrors({ApiError.INVALID_ADDRESS, ApiError.ADDRESS_UNKNOWN, ApiError.REPOSITORY_ISSUE})
+	public String getLastReference(@PathParam("address") String address) {
 		if (!Crypto.isValidAddress(address))
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_ADDRESS);
 
 		byte[] lastReference = null;
 
 		try (final Repository repository = RepositoryManager.getRepository()) {
-			Account account = new Account(repository, address);
+			AccountData accountData = repository.getAccountRepository().getAccount(address);
+			// Not found?
+			if (accountData == null)
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.ADDRESS_UNKNOWN);
 
-			// Use last reference based on unconfirmed transactions if possible
-			lastReference = account.getUnconfirmedLastReference();
-
-			if (lastReference == null)
-				// No unconfirmed transactions so fallback to using one save in account data
-				lastReference = account.getLastReference();
-		} catch (ApiException e) {
-			throw e;
+			lastReference = accountData.getReference();
 		} catch (DataException e) {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
 		}
 
-		if(lastReference == null || lastReference.length == 0) {
+		if (lastReference == null || lastReference.length == 0)
 			return "false";
-		} else {
-			return Base58.encode(lastReference);
-		}
+
+		return Base58.encode(lastReference);
 	}
 
 	@GET
@@ -192,7 +184,7 @@ public class AddressesResource {
 	@Path("/balance/{address}")
 	@Operation(
 		summary = "Returns account balance",
-		description = "Returns account's balance, optionally of given asset and at given height",
+		description = "Returns account's QORT balance, or of other specified asset",
 		responses = {
 			@ApiResponse(
 				description = "the balance",
@@ -202,8 +194,7 @@ public class AddressesResource {
 	)
 	@ApiErrors({ApiError.INVALID_ADDRESS, ApiError.INVALID_ASSET_ID, ApiError.INVALID_HEIGHT,  ApiError.REPOSITORY_ISSUE})
 	public BigDecimal getBalance(@PathParam("address") String address,
-			@QueryParam("assetId") Long assetId,
-			@QueryParam("height") Integer height) {
+			@QueryParam("assetId") Long assetId) {
 		if (!Crypto.isValidAddress(address))
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_ADDRESS);
 
@@ -215,12 +206,7 @@ public class AddressesResource {
 			else if (!repository.getAssetRepository().assetExists(assetId))
 				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_ASSET_ID);
 
-			if (height == null)
-				height = repository.getBlockRepository().getBlockchainHeight();
-			else if (height <= 0)
-				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_HEIGHT);
-
-			return account.getBalance(assetId, height);
+			return Amounts.toBigDecimal(account.getConfirmedBalance(assetId));
 		} catch (ApiException e) {
 			throw e;
 		} catch (DataException e) {
@@ -414,4 +400,120 @@ public class AddressesResource {
 		}
 	}
 
+	@POST
+	@Path("/publicize")
+	@Operation(
+		summary = "Build raw, unsigned, PUBLICIZE transaction",
+		requestBody = @RequestBody(
+			required = true,
+			content = @Content(
+				mediaType = MediaType.APPLICATION_JSON,
+				schema = @Schema(
+					implementation = PublicizeTransactionData.class
+				)
+			)
+		),
+		responses = {
+			@ApiResponse(
+				description = "raw, unsigned, PUBLICIZE 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 publicize(PublicizeTransactionData 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);
+
+			ValidationResult result = transaction.isValidUnconfirmed();
+			if (result != ValidationResult.OK && result != ValidationResult.INCORRECT_NONCE)
+				throw TransactionsResource.createTransactionInvalidException(request, result);
+
+			byte[] bytes = PublicizeTransactionTransformer.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("/publicize/compute")
+	@Operation(
+		summary = "Compute nonce for raw, unsigned PUBLICIZE transaction",
+		requestBody = @RequestBody(
+			required = true,
+			content = @Content(
+				mediaType = MediaType.TEXT_PLAIN,
+				schema = @Schema(
+					type = "string",
+					description = "raw, unsigned PUBLICIZE transaction in base58 encoding",
+					example = "raw transaction base58"
+				)
+			)
+		),
+		responses = {
+			@ApiResponse(
+				description = "raw, unsigned, PUBLICIZE transaction encoded in Base58",
+				content = @Content(
+					mediaType = MediaType.TEXT_PLAIN,
+					schema = @Schema(
+						type = "string"
+					)
+				)
+			)
+		}
+	)
+	@ApiErrors({ApiError.TRANSACTION_INVALID, ApiError.INVALID_DATA, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
+	public String computePublicize(String rawBytes58) {
+		Security.checkApiCallAllowed(request);
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			byte[] rawBytes = Base58.decode(rawBytes58);
+			// We're expecting unsigned transaction, so append empty signature prior to decoding
+			rawBytes = Bytes.concat(rawBytes, new byte[TransactionTransformer.SIGNATURE_LENGTH]);
+
+			TransactionData transactionData = TransactionTransformer.fromBytes(rawBytes);
+			if (transactionData == null)
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_DATA);
+
+			if (transactionData.getType() != TransactionType.PUBLICIZE)
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_DATA);
+
+			PublicizeTransaction publicizeTransaction = (PublicizeTransaction) Transaction.fromData(repository, transactionData);
+
+			// Quicker validity check first before we compute nonce
+			ValidationResult result = publicizeTransaction.isValid();
+			if (result != ValidationResult.OK && result != ValidationResult.INCORRECT_NONCE)
+				throw TransactionsResource.createTransactionInvalidException(request, result);
+
+			publicizeTransaction.computeNonce();
+
+			// Re-check, but ignores signature
+			result = publicizeTransaction.isValidUnconfirmed();
+			if (result != ValidationResult.OK)
+				throw TransactionsResource.createTransactionInvalidException(request, result);
+
+			// Strip zeroed signature
+			transactionData.setSignature(null);
+
+			byte[] bytes = PublicizeTransactionTransformer.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/AdminResource.java

@@ -8,6 +8,7 @@ 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.security.SecurityRequirement;
 import io.swagger.v3.oas.annotations.tags.Tag;
 
 import java.io.IOException;
@@ -36,15 +37,15 @@ import javax.ws.rs.core.MediaType;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.core.LoggerContext;
 import org.apache.logging.log4j.core.appender.RollingFileAppender;
+import org.qortal.account.Account;
 import org.qortal.account.PrivateKeyAccount;
-import org.qortal.account.PublicKeyAccount;
 import org.qortal.api.ApiError;
 import org.qortal.api.ApiErrors;
-import org.qortal.api.ApiException;
 import org.qortal.api.ApiExceptionFactory;
 import org.qortal.api.Security;
 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.Controller;
 import org.qortal.controller.Synchronizer.SynchronizationResult;
@@ -56,6 +57,7 @@ import org.qortal.network.PeerAddress;
 import org.qortal.repository.DataException;
 import org.qortal.repository.Repository;
 import org.qortal.repository.RepositoryManager;
+import org.qortal.settings.Settings;
 import org.qortal.utils.Base58;
 import org.qortal.utils.NTP;
 
@@ -116,10 +118,31 @@ public class AdminResource {
 		nodeInfo.uptime = System.currentTimeMillis() - Controller.startTime;
 		nodeInfo.buildVersion = Controller.getInstance().getVersionString();
 		nodeInfo.buildTimestamp = Controller.getInstance().getBuildTimestamp();
+		nodeInfo.nodeId = Network.getInstance().getOurNodeId();
+		nodeInfo.isTestNet = Settings.getInstance().isTestNet();
 
 		return nodeInfo;
 	}
 
+	@GET
+	@Path("/status")
+	@Operation(
+		summary = "Fetch node status",
+		responses = {
+			@ApiResponse(
+				content = @Content(mediaType = MediaType.APPLICATION_JSON, schema = @Schema(implementation = NodeStatus.class))
+			)
+		}
+	)
+	@SecurityRequirement(name = "apiKey")
+	public NodeStatus status() {
+		Security.checkApiCallAllowed(request);
+
+		NodeStatus nodeStatus = new NodeStatus();
+
+		return nodeStatus;
+	}
+
 	@GET
 	@Path("/stop")
 	@Operation(
@@ -132,6 +155,7 @@ public class AdminResource {
 			)
 		}
 	)
+	@SecurityRequirement(name = "apiKey")
 	public String shutdown() {
 		Security.checkApiCallAllowed(request);
 
@@ -160,7 +184,10 @@ public class AdminResource {
 		}
 	)
 	@ApiErrors({ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
 	public ActivitySummary summary() {
+		Security.checkApiCallAllowed(request);
+
 		ActivitySummary summary = new ActivitySummary();
 
 		LocalDate date = LocalDate.now();
@@ -172,16 +199,13 @@ public class AdminResource {
 			int startHeight = repository.getBlockRepository().getHeightFromTimestamp(start);
 			int endHeight = repository.getBlockRepository().getBlockchainHeight();
 
-			summary.blockCount = endHeight - startHeight;
+			summary.setBlockCount(endHeight - startHeight);
 
-			summary.transactionCountByType = repository.getTransactionRepository().getTransactionSummary(startHeight + 1, endHeight);
+			summary.setTransactionCountByType(repository.getTransactionRepository().getTransactionSummary(startHeight + 1, endHeight));
 
-			for (Integer count : summary.transactionCountByType.values())
-				summary.transactionCount += count;
+			summary.setAssetsIssued(repository.getAssetRepository().getRecentAssetIds(start).size());
 
-			summary.assetsIssued = repository.getAssetRepository().getRecentAssetIds(start).size();
-
-			summary.namesRegistered = repository.getNameRepository().getRecentNames(start).size();
+			summary.setNamesRegistered (repository.getNameRepository().getRecentNames(start).size());
 
 			return summary;
 		} catch (DataException e) {
@@ -189,6 +213,30 @@ public class AdminResource {
 		}
 	}
 
+	@GET
+	@Path("/enginestats")
+	@Operation(
+		summary = "Fetch statistics snapshot for core engine",
+		responses = {
+			@ApiResponse(
+				content = @Content(
+					mediaType = MediaType.APPLICATION_JSON,
+					array = @ArraySchema(
+						schema = @Schema(
+							implementation = Controller.StatsSnapshot.class
+						)
+					)
+				)
+			)
+		}
+	)
+	@SecurityRequirement(name = "apiKey")
+	public Controller.StatsSnapshot getEngineStats() {
+		Security.checkApiCallAllowed(request);
+
+		return Controller.getInstance().getStatsSnapshot();
+	}
+
 	@GET
 	@Path("/mintingaccounts")
 	@Operation(
@@ -201,6 +249,7 @@ public class AdminResource {
 		}
 	)
 	@ApiErrors({ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
 	public List<MintingAccountData> getMintingAccounts() {
 		Security.checkApiCallAllowed(request);
 
@@ -218,7 +267,7 @@ public class AdminResource {
 					// ignore
 				}
 
-				return new MintingAccountData(mintingAccountData.getPrivateKey(), rewardShareData);
+				return new MintingAccountData(mintingAccountData, rewardShareData);
 			}).collect(Collectors.toList());
 
 			return mintingAccounts;
@@ -247,6 +296,7 @@ public class AdminResource {
 		}
 	)
 	@ApiErrors({ApiError.INVALID_PRIVATE_KEY, ApiError.REPOSITORY_ISSUE, ApiError.CANNOT_MINT})
+	@SecurityRequirement(name = "apiKey")
 	public String addMintingAccount(String seed58) {
 		Security.checkApiCallAllowed(request);
 
@@ -262,11 +312,11 @@ public class AdminResource {
 				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_PRIVATE_KEY);
 
 			// Qortal: check reward-share's minting account is still allowed to mint
-			PublicKeyAccount rewardShareMintingAccount = new PublicKeyAccount(repository, rewardShareData.getMinterPublicKey());
+			Account rewardShareMintingAccount = new Account(repository, rewardShareData.getMinter());
 			if (!rewardShareMintingAccount.canMint())
 				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.CANNOT_MINT);
 
-			MintingAccountData mintingAccountData = new MintingAccountData(seed);
+			MintingAccountData mintingAccountData = new MintingAccountData(mintingAccount.getPrivateKey(), mintingAccount.getPublicKey());
 
 			repository.getAccountRepository().save(mintingAccountData);
 			repository.saveChanges();
@@ -282,13 +332,13 @@ public class AdminResource {
 	@DELETE
 	@Path("/mintingaccounts")
 	@Operation(
-		summary = "Remove account/reward-share from use by BlockMinter, using private key",
+		summary = "Remove account/reward-share from use by BlockMinter, using public or private key",
 		requestBody = @RequestBody(
 			required = true,
 			content = @Content(
 				mediaType = MediaType.TEXT_PLAIN,
 				schema = @Schema(
-					type = "string", example = "private key"
+					type = "string", example = "public or private key"
 				)
 			)
 		),
@@ -299,13 +349,14 @@ public class AdminResource {
 		}
 	)
 	@ApiErrors({ApiError.INVALID_PRIVATE_KEY, ApiError.REPOSITORY_ISSUE})
-	public String deleteMintingAccount(String seed58) {
+	@SecurityRequirement(name = "apiKey")
+	public String deleteMintingAccount(String key58) {
 		Security.checkApiCallAllowed(request);
 
 		try (final Repository repository = RepositoryManager.getRepository()) {
-			byte[] seed = Base58.decode(seed58.trim());
+			byte[] key = Base58.decode(key58.trim());
 
-			if (repository.getAccountRepository().delete(seed) == 0)
+			if (repository.getAccountRepository().delete(key) == 0)
 				return "false";
 
 			repository.saveChanges();
@@ -398,6 +449,7 @@ public class AdminResource {
 		}
 	)
 	@ApiErrors({ApiError.INVALID_HEIGHT, ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
 	public String orphan(String targetHeightString) {
 		Security.checkApiCallAllowed(request);
 
@@ -415,8 +467,6 @@ public class AdminResource {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
 		} catch (NumberFormatException e) {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_HEIGHT);
-		} catch (ApiException e) {
-			throw e;
 		}
 	}
 
@@ -441,6 +491,7 @@ public class AdminResource {
 		}
 	)
 	@ApiErrors({ApiError.INVALID_DATA, ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
 	public String forceSync(String targetPeerAddress) {
 		Security.checkApiCallAllowed(request);
 
@@ -472,8 +523,6 @@ public class AdminResource {
 			return syncResult.name();
 		} catch (IllegalArgumentException e) {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_DATA);
-		} catch (ApiException e) {
-			throw e;
 		} catch (UnknownHostException e) {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_DATA);
 		} catch (InterruptedException e) {
@@ -481,4 +530,172 @@ public class AdminResource {
 		}
 	}
 
+	@GET
+	@Path("/repository/data")
+	@Operation(
+		summary = "Export sensitive/node-local data from repository.",
+		description = "Exports data to .script files on local machine"
+	)
+	@ApiErrors({ApiError.INVALID_DATA, ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
+	public String exportRepository() {
+		Security.checkApiCallAllowed(request);
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			ReentrantLock blockchainLock = Controller.getInstance().getBlockchainLock();
+
+			blockchainLock.lockInterruptibly();
+
+			try {
+				repository.exportNodeLocalData();
+				return "true";
+			} finally {
+				blockchainLock.unlock();
+			}
+		} catch (InterruptedException e) {
+			// We couldn't lock blockchain to perform export
+			return "false";
+		} catch (DataException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
+		}
+	}
+
+	@POST
+	@Path("/repository/data")
+	@Operation(
+		summary = "Import data into repository.",
+		description = "Imports data from file on local machine. Filename is forced to 'import.script' if apiKey is not set.",
+		requestBody = @RequestBody(
+			required = true,
+			content = @Content(
+				mediaType = MediaType.TEXT_PLAIN,
+				schema = @Schema(
+					type = "string", example = "MintingAccounts.script"
+				)
+			)
+		),
+		responses = {
+			@ApiResponse(
+				description = "\"true\"",
+				content = @Content(mediaType = MediaType.TEXT_PLAIN, schema = @Schema(type = "string"))
+			)
+		}
+	)
+	@ApiErrors({ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
+	public String importRepository(String filename) {
+		Security.checkApiCallAllowed(request);
+
+		// Hard-coded because it's too dangerous to allow user-supplied filenames in weaker security contexts
+		if (Settings.getInstance().getApiKey() == null)
+			filename = "import.script";
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			ReentrantLock blockchainLock = Controller.getInstance().getBlockchainLock();
+
+			blockchainLock.lockInterruptibly();
+
+			try {
+				repository.importDataFromFile(filename);
+				repository.saveChanges();
+
+				return "true";
+			} finally {
+				blockchainLock.unlock();
+			}
+		} catch (InterruptedException e) {
+			// We couldn't lock blockchain to perform import
+			return "false";
+		} catch (DataException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
+		}
+	}
+
+	@POST
+	@Path("/repository/checkpoint")
+	@Operation(
+		summary = "Checkpoint data in repository.",
+		description = "Forces repository to checkpoint uncommitted writes.",
+		responses = {
+			@ApiResponse(
+				description = "\"true\"",
+				content = @Content(mediaType = MediaType.TEXT_PLAIN, schema = @Schema(type = "string"))
+			)
+		}
+	)
+	@ApiErrors({ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
+	public String checkpointRepository() {
+		Security.checkApiCallAllowed(request);
+
+		RepositoryManager.setRequestedCheckpoint(Boolean.TRUE);
+
+		return "true";
+	}
+
+	@POST
+	@Path("/repository/backup")
+	@Operation(
+		summary = "Perform online backup of repository.",
+		responses = {
+			@ApiResponse(
+				description = "\"true\"",
+				content = @Content(mediaType = MediaType.TEXT_PLAIN, schema = @Schema(type = "string"))
+			)
+		}
+	)
+	@ApiErrors({ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
+	public String backupRepository() {
+		Security.checkApiCallAllowed(request);
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			ReentrantLock blockchainLock = Controller.getInstance().getBlockchainLock();
+
+			blockchainLock.lockInterruptibly();
+
+			try {
+				repository.backup(true);
+				repository.saveChanges();
+
+				return "true";
+			} finally {
+				blockchainLock.unlock();
+			}
+		} catch (InterruptedException e) {
+			// We couldn't lock blockchain to perform backup
+			return "false";
+		} catch (DataException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
+		}
+	}
+
+	@DELETE
+	@Path("/repository")
+	@Operation(
+		summary = "Perform maintenance on repository.",
+		description = "Requires enough free space to rebuild repository. This will pause your node for a while."
+	)
+	@ApiErrors({ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
+	public void performRepositoryMaintenance() {
+		Security.checkApiCallAllowed(request);
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			ReentrantLock blockchainLock = Controller.getInstance().getBlockchainLock();
+
+			blockchainLock.lockInterruptibly();
+
+			try {
+				repository.performPeriodicMaintenance();
+			} finally {
+				blockchainLock.unlock();
+			}
+		} catch (InterruptedException e) {
+			// No big deal
+		} catch (DataException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
+		}
+	}
+
 }

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

@@ -1,11 +1,17 @@
 package org.qortal.api.resource;
 
 import io.swagger.v3.oas.annotations.OpenAPIDefinition;
+import io.swagger.v3.oas.annotations.enums.SecuritySchemeIn;
+import io.swagger.v3.oas.annotations.enums.SecuritySchemeType;
 import io.swagger.v3.oas.annotations.extensions.Extension;
 import io.swagger.v3.oas.annotations.extensions.ExtensionProperty;
 import io.swagger.v3.oas.annotations.info.Info;
+import io.swagger.v3.oas.annotations.security.SecurityScheme;
+import io.swagger.v3.oas.annotations.security.SecuritySchemes;
 import io.swagger.v3.oas.annotations.tags.Tag;
 
+import org.qortal.api.Security;
+
 @OpenAPIDefinition(
 		info = @Info( title = "Qortal API", description = "NOTE: byte-arrays are encoded in Base58" ),
 		tags = {
@@ -13,7 +19,10 @@ import io.swagger.v3.oas.annotations.tags.Tag;
 			@Tag(name = "Admin"),
 			@Tag(name = "Arbitrary"),
 			@Tag(name = "Assets"),
+			@Tag(name = "Automated Transactions"),
 			@Tag(name = "Blocks"),
+			@Tag(name = "Chat"),
+			@Tag(name = "Cross-Chain"),
 			@Tag(name = "Groups"),
 			@Tag(name = "Names"),
 			@Tag(name = "Payments"),
@@ -27,5 +36,9 @@ import io.swagger.v3.oas.annotations.tags.Tag;
 			})
 		}
 )
+@SecuritySchemes({
+	@SecurityScheme(name = "basicAuth", type = SecuritySchemeType.HTTP, scheme = "basic"),
+	@SecurityScheme(name = "apiKey", type = SecuritySchemeType.APIKEY, in = SecuritySchemeIn.HEADER, paramName = Security.API_KEY_HEADER)
+})
 public class ApiDefinition {
 }

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

@@ -0,0 +1,204 @@
+package org.qortal.api.resource;
+
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.Parameter;
+import io.swagger.v3.oas.annotations.media.ArraySchema;
+import io.swagger.v3.oas.annotations.media.Content;
+import io.swagger.v3.oas.annotations.media.Schema;
+import io.swagger.v3.oas.annotations.parameters.RequestBody;
+import io.swagger.v3.oas.annotations.responses.ApiResponse;
+import io.swagger.v3.oas.annotations.tags.Tag;
+
+import java.util.List;
+
+import 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.core.Context;
+import javax.ws.rs.core.MediaType;
+
+import org.ciyam.at.MachineState;
+import org.qortal.api.ApiError;
+import org.qortal.api.ApiErrors;
+import org.qortal.api.ApiException;
+import org.qortal.api.ApiExceptionFactory;
+import org.qortal.data.at.ATData;
+import org.qortal.data.at.ATStateData;
+import org.qortal.data.transaction.DeployAtTransactionData;
+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.transaction.Transaction.ValidationResult;
+import org.qortal.transform.TransformationException;
+import org.qortal.transform.transaction.DeployAtTransactionTransformer;
+import org.qortal.utils.Base58;
+
+@Path("/at")
+@Tag(name = "Automated Transactions")
+public class AtResource {
+
+	@Context
+	HttpServletRequest request;
+
+	@GET
+	@Path("/byfunction/{codehash}")
+	@Operation(
+		summary = "Find automated transactions with matching functionality (code hash)",
+		responses = {
+			@ApiResponse(
+				description = "automated transactions",
+				content = @Content(
+					array = @ArraySchema(
+						schema = @Schema(
+							implementation = ATData.class
+						)
+					)
+				)
+			)
+		}
+	)
+	@ApiErrors({
+		ApiError.INVALID_CRITERIA, ApiError.REPOSITORY_ISSUE
+	})
+	public List<ATData> getByFunctionality(
+			@PathParam("codehash")
+			String codeHash58,
+			@Parameter(description = "whether to include ATs that can run, or not, or both (if omitted)")
+			@QueryParam("isExecutable")
+			Boolean isExecutable,
+			@Parameter( ref = "limit") @QueryParam("limit") Integer limit,
+			@Parameter( ref = "offset" ) @QueryParam("offset") Integer offset,
+			@Parameter( ref = "reverse" ) @QueryParam("reverse") Boolean reverse) {
+		// Decode codeHash
+		byte[] codeHash;
+		try {
+			codeHash = Base58.decode(codeHash58);
+		} catch (NumberFormatException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA, e);
+		}
+
+		// codeHash must be present and have correct length
+		if (codeHash == null || codeHash.length != 32)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+
+		// Impose a limit on 'limit'
+		if (limit != null && limit > 100)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			return repository.getATRepository().getATsByFunctionality(codeHash, isExecutable, limit, offset, reverse);
+		} catch (ApiException e) {
+			throw e;
+		} catch (DataException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
+		}
+	}
+
+	@GET
+	@Path("/{ataddress}")
+	@Operation(
+		summary = "Fetch info associated with AT address",
+		responses = {
+			@ApiResponse(
+				description = "automated transaction",
+				content = @Content(
+					schema = @Schema(implementation = ATData.class)
+				)
+			)
+		}
+	)
+	@ApiErrors({
+		ApiError.REPOSITORY_ISSUE
+	})
+	public ATData getByAddress(@PathParam("ataddress") String atAddress) {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			return repository.getATRepository().fromATAddress(atAddress);
+		} catch (ApiException e) {
+			throw e;
+		} catch (DataException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
+		}
+	}
+
+	@GET
+	@Path("/{ataddress}/data")
+	@Operation(
+		summary = "Fetch data segment associated with AT address",
+		responses = {
+			@ApiResponse(
+				description = "automated transaction",
+				content = @Content(
+					schema = @Schema(implementation = byte[].class)
+				)
+			)
+		}
+	)
+	@ApiErrors({
+		ApiError.REPOSITORY_ISSUE
+	})
+	public byte[] getDataByAddress(@PathParam("ataddress") String atAddress) {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			ATStateData atStateData = repository.getATRepository().getLatestATState(atAddress);
+			byte[] stateData = atStateData.getStateData();
+
+			byte[] dataBytes = MachineState.extractDataBytes(stateData);
+
+			return dataBytes;
+		} catch (ApiException e) {
+			throw e;
+		} catch (DataException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
+		}
+	}
+
+	@POST
+	@Operation(
+		summary = "Build raw, unsigned, DEPLOY_AT transaction",
+		requestBody = @RequestBody(
+			required = true,
+			content = @Content(
+				mediaType = MediaType.APPLICATION_JSON,
+				schema = @Schema(
+					implementation = DeployAtTransactionData.class
+				)
+			)
+		),
+		responses = {
+			@ApiResponse(
+				description = "raw, unsigned, DEPLOY_AT 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 createDeployAt(DeployAtTransactionData 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);
+
+			ValidationResult result = transaction.isValidUnconfirmed();
+			if (result != ValidationResult.OK)
+				throw TransactionsResource.createTransactionInvalidException(request, result);
+
+			byte[] bytes = DeployAtTransactionTransformer.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/BlocksResource.java

@@ -22,9 +22,8 @@ import javax.ws.rs.core.MediaType;
 
 import org.qortal.api.ApiError;
 import org.qortal.api.ApiErrors;
-import org.qortal.api.ApiException;
 import org.qortal.api.ApiExceptionFactory;
-import org.qortal.api.model.BlockMinterSummary;
+import org.qortal.api.model.BlockSignerSummary;
 import org.qortal.crypto.Crypto;
 import org.qortal.data.account.AccountData;
 import org.qortal.data.block.BlockData;
@@ -71,9 +70,11 @@ public class BlocksResource {
 		}
 
 		try (final Repository repository = RepositoryManager.getRepository()) {
-			return repository.getBlockRepository().fromSignature(signature);
-		} catch (ApiException e) {
-			throw e;
+			BlockData blockData = repository.getBlockRepository().fromSignature(signature);
+			if (blockData == null)
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.BLOCK_UNKNOWN);
+
+			return blockData;
 		} catch (DataException e) {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
 		}
@@ -120,8 +121,6 @@ public class BlocksResource {
 				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.BLOCK_UNKNOWN);
 
 			return repository.getBlockRepository().getTransactionsFromSignature(signature, limit, offset, reverse);
-		} catch (ApiException e) {
-			throw e;
 		} catch (DataException e) {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
 		}
@@ -223,8 +222,6 @@ public class BlocksResource {
 				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.BLOCK_UNKNOWN);
 
 			return childBlockData;
-		} catch (ApiException e) {
-			throw e;
 		} catch (DataException e) {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
 		}
@@ -253,8 +250,6 @@ public class BlocksResource {
 	public int getHeight() {
 		try (final Repository repository = RepositoryManager.getRepository()) {
 			return repository.getBlockRepository().getBlockchainHeight();
-		} catch (ApiException e) {
-			throw e;
 		} catch (DataException e) {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
 		}
@@ -297,8 +292,6 @@ public class BlocksResource {
 				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.BLOCK_UNKNOWN);
 
 			return blockData.getHeight();
-		} catch (ApiException e) {
-			throw e;
 		} catch (DataException e) {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
 		}
@@ -330,8 +323,6 @@ public class BlocksResource {
 				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.BLOCK_UNKNOWN);
 
 			return blockData;
-		} catch (ApiException e) {
-			throw e;
 		} catch (DataException e) {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
 		}
@@ -366,8 +357,6 @@ public class BlocksResource {
 				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.BLOCK_UNKNOWN);
 
 			return blockData;
-		} catch (ApiException e) {
-			throw e;
 		} catch (DataException e) {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
 		}
@@ -416,9 +405,9 @@ public class BlocksResource {
 	}
 
 	@GET
-	@Path("/minter/{address}")
+	@Path("/signer/{address}")
 	@Operation(
-		summary = "Fetch block summaries for blocks minted by address",
+		summary = "Fetch block summaries for blocks signed by address",
 		responses = {
 			@ApiResponse(
 				description = "block summaries",
@@ -433,7 +422,7 @@ public class BlocksResource {
 		}
 	)
 	@ApiErrors({ApiError.INVALID_ADDRESS, ApiError.PUBLIC_KEY_NOT_FOUND, ApiError.REPOSITORY_ISSUE})
-	public List<BlockSummaryData> getBlockSummariesByMinter(@PathParam("address") String address, @Parameter(
+	public List<BlockSummaryData> getBlockSummariesBySigner(@PathParam("address") String address, @Parameter(
 			ref = "limit"
 			) @QueryParam("limit") Integer limit, @Parameter(
 				ref = "offset"
@@ -449,32 +438,30 @@ public class BlocksResource {
 			if (accountData == null || accountData.getPublicKey() == null)
 				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.PUBLIC_KEY_NOT_FOUND);
 
-			return repository.getBlockRepository().getBlockSummariesByMinter(accountData.getPublicKey(), limit, offset, reverse);
-		} catch (ApiException e) {
-			throw e;
+			return repository.getBlockRepository().getBlockSummariesBySigner(accountData.getPublicKey(), limit, offset, reverse);
 		} catch (DataException e) {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
 		}
 	}
 
 	@GET
-	@Path("/minters")
+	@Path("/signers")
 	@Operation(
-		summary = "Show summary of block minters",
-		description = "Returns count of blocks minted, optionally limited to minters/recipients in passed address(es).",
+		summary = "Show summary of block signers",
+		description = "Returns count of blocks signed, optionally limited to minters/recipients in passed address(es).",
 		responses = {
 			@ApiResponse(
 				content = @Content(
 					array = @ArraySchema(
 						schema = @Schema(
-							implementation = BlockMinterSummary.class
+							implementation = BlockSignerSummary.class
 						)
 					)
 				)
 			)
 		}
 	)
-	public List<BlockMinterSummary> getBlockMinters(@QueryParam("address") List<String> addresses,
+	public List<BlockSignerSummary> getBlockSigners(@QueryParam("address") List<String> addresses,
 			@Parameter(
 				ref = "limit"
 			) @QueryParam("limit") Integer limit, @Parameter(
@@ -487,7 +474,47 @@ public class BlocksResource {
 				if (!Crypto.isValidAddress(address))
 					throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_ADDRESS);
 
-			return repository.getBlockRepository().getBlockMinters(addresses, limit, offset, reverse);
+			return repository.getBlockRepository().getBlockSigners(addresses, limit, offset, reverse);
+		} catch (DataException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
+		}
+	}
+
+	@GET
+	@Path("/summaries")
+	@Operation(
+		summary = "Fetch only summary info about a range of blocks",
+		description = "Specify up to 2 out 3 of: start, end and count. If neither start nor end are specified, then end is assumed to be latest block. Where necessary, count is assumed to be 50.",
+		responses = {
+			@ApiResponse(
+				description = "blocks",
+				content = @Content(
+					array = @ArraySchema(
+						schema = @Schema(
+							implementation = BlockSummaryData.class
+						)
+					)
+				)
+			)
+		}
+	)
+	@ApiErrors({
+		ApiError.REPOSITORY_ISSUE
+	})
+	public List<BlockSummaryData> getBlockSummaries(
+			@QueryParam("start") Integer startHeight,
+			@QueryParam("end") Integer endHeight,
+			@Parameter(ref = "count") @QueryParam("count") Integer count) {
+		// Check up to 2 out of 3 params
+		if (startHeight != null && endHeight != null && count != null)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+
+		// Check values
+		if ((startHeight != null && startHeight < 1) || (endHeight != null && endHeight < 1) || (count != null && count < 1))
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			return repository.getBlockRepository().getBlockSummaries(startHeight, endHeight, count);
 		} catch (DataException e) {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
 		}

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

@@ -0,0 +1,250 @@
+package org.qortal.api.resource;
+
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.Parameter;
+import io.swagger.v3.oas.annotations.media.ArraySchema;
+import io.swagger.v3.oas.annotations.media.Content;
+import io.swagger.v3.oas.annotations.media.Schema;
+import io.swagger.v3.oas.annotations.parameters.RequestBody;
+import io.swagger.v3.oas.annotations.responses.ApiResponse;
+import io.swagger.v3.oas.annotations.security.SecurityRequirement;
+import io.swagger.v3.oas.annotations.tags.Tag;
+
+import java.util.List;
+
+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.core.Context;
+import javax.ws.rs.core.MediaType;
+
+import org.qortal.api.ApiError;
+import org.qortal.api.ApiErrors;
+import org.qortal.api.ApiExceptionFactory;
+import org.qortal.api.Security;
+import org.qortal.crypto.Crypto;
+import org.qortal.data.chat.ActiveChats;
+import org.qortal.data.chat.ChatMessage;
+import org.qortal.data.transaction.ChatTransactionData;
+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.ChatTransaction;
+import org.qortal.transaction.Transaction;
+import org.qortal.transaction.Transaction.TransactionType;
+import org.qortal.transaction.Transaction.ValidationResult;
+import org.qortal.transform.TransformationException;
+import org.qortal.transform.transaction.ChatTransactionTransformer;
+import org.qortal.transform.transaction.TransactionTransformer;
+import org.qortal.utils.Base58;
+
+import com.google.common.primitives.Bytes;
+
+@Path("/chat")
+@Tag(name = "Chat")
+public class ChatResource {
+
+	@Context
+	HttpServletRequest request;
+
+	@GET
+	@Path("/messages")
+	@Operation(
+		summary = "Find chat messages",
+		description = "Returns CHAT messages that match criteria. Must provide EITHER 'txGroupId' OR two 'involving' addresses.",
+		responses = {
+			@ApiResponse(
+				description = "CHAT messages",
+				content = @Content(
+					array = @ArraySchema(
+						schema = @Schema(
+							implementation = ChatMessage.class
+						)
+					)
+				)
+			)
+		}
+	)
+	@ApiErrors({ApiError.INVALID_CRITERIA, ApiError.INVALID_ADDRESS, ApiError.REPOSITORY_ISSUE})
+	public List<ChatMessage> searchChat(@QueryParam("before") Long before, @QueryParam("after") Long after,
+			@QueryParam("txGroupId") Integer txGroupId,
+			@QueryParam("involving") List<String> involvingAddresses,
+			@Parameter(ref = "limit") @QueryParam("limit") Integer limit,
+			@Parameter(ref = "offset") @QueryParam("offset") Integer offset,
+			@Parameter(ref = "reverse") @QueryParam("reverse") Boolean reverse) {
+		// Check args meet expectations
+		if ((txGroupId == null && involvingAddresses.size() != 2)
+				|| (txGroupId != null && !involvingAddresses.isEmpty()))
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+
+		// Check any provided addresses are valid
+		if (involvingAddresses.stream().anyMatch(address -> !Crypto.isValidAddress(address)))
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_ADDRESS);
+
+		if (before != null && before < 1500000000000L)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+
+		if (after != null && after < 1500000000000L)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			return repository.getChatRepository().getMessagesMatchingCriteria(
+					before,
+					after,
+					txGroupId,
+					involvingAddresses,
+					limit, offset, reverse);
+		} catch (DataException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
+		}
+	}
+
+	@GET
+	@Path("/active/{address}")
+	@Operation(
+		summary = "Find active chats (group/direct) involving address",
+		responses = {
+			@ApiResponse(
+				content = @Content(
+					array = @ArraySchema(
+						schema = @Schema(
+							implementation = ActiveChats.class
+						)
+					)
+				)
+			)
+		}
+	)
+	@ApiErrors({ApiError.INVALID_CRITERIA, ApiError.INVALID_ADDRESS, ApiError.REPOSITORY_ISSUE})
+	public ActiveChats getActiveChats(@PathParam("address") String address) {
+		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);
+		} catch (DataException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
+		}
+	}
+
+	@POST
+	@Operation(
+		summary = "Build raw, unsigned, CHAT transaction",
+		description = "Builds a raw, unsigned CHAT transaction but does NOT compute proof-of-work nonce. See POST /chat/compute.",
+		requestBody = @RequestBody(
+			required = true,
+			content = @Content(
+				mediaType = MediaType.APPLICATION_JSON,
+				schema = @Schema(
+					implementation = ChatTransactionData.class
+				)
+			)
+		),
+		responses = {
+			@ApiResponse(
+				description = "raw, unsigned, CHAT transaction encoded in Base58",
+				content = @Content(
+					mediaType = MediaType.TEXT_PLAIN,
+					schema = @Schema(
+						type = "string"
+					)
+				)
+			)
+		}
+	)
+	@ApiErrors({ApiError.TRANSACTION_INVALID, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
+	public String buildChat(ChatTransactionData transactionData) {
+		Security.checkApiCallAllowed(request);
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			ChatTransaction chatTransaction = (ChatTransaction) Transaction.fromData(repository, transactionData);
+
+			ValidationResult result = chatTransaction.isValidUnconfirmed();
+			if (result != ValidationResult.OK)
+				throw TransactionsResource.createTransactionInvalidException(request, result);
+
+			byte[] bytes = ChatTransactionTransformer.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("/compute")
+	@Operation(
+		summary = "Compute nonce for raw, unsigned CHAT transaction",
+		requestBody = @RequestBody(
+			required = true,
+			content = @Content(
+				mediaType = MediaType.TEXT_PLAIN,
+				schema = @Schema(
+					type = "string",
+					description = "raw, unsigned CHAT transaction in base58 encoding",
+					example = "raw transaction base58"
+				)
+			)
+		),
+		responses = {
+			@ApiResponse(
+				description = "raw, unsigned, CHAT transaction encoded in Base58",
+				content = @Content(
+					mediaType = MediaType.TEXT_PLAIN,
+					schema = @Schema(
+						type = "string"
+					)
+				)
+			)
+		}
+	)
+	@ApiErrors({ApiError.TRANSACTION_INVALID, ApiError.INVALID_DATA, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
+	public String buildChat(String rawBytes58) {
+		Security.checkApiCallAllowed(request);
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			byte[] rawBytes = Base58.decode(rawBytes58);
+			// We're expecting unsigned transaction, so append empty signature prior to decoding
+			rawBytes = Bytes.concat(rawBytes, new byte[TransactionTransformer.SIGNATURE_LENGTH]);
+
+			TransactionData transactionData = TransactionTransformer.fromBytes(rawBytes);
+			if (transactionData == null)
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_DATA);
+
+			if (transactionData.getType() != TransactionType.CHAT)
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_DATA);
+
+			ChatTransaction chatTransaction = (ChatTransaction) Transaction.fromData(repository, transactionData);
+
+			// Quicker validity check first before we compute nonce
+			ValidationResult result = chatTransaction.isValid();
+			if (result != ValidationResult.OK)
+				throw TransactionsResource.createTransactionInvalidException(request, result);
+
+			chatTransaction.computeNonce();
+
+			// Re-check, but ignores signature
+			result = chatTransaction.isValidUnconfirmed();
+			if (result != ValidationResult.OK)
+				throw TransactionsResource.createTransactionInvalidException(request, result);
+
+			// Strip zeroed signature
+			transactionData.setSignature(null);
+
+			byte[] bytes = ChatTransactionTransformer.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/CrossChainBitcoinACCTv1Resource.java

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

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

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

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

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

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

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

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

@@ -0,0 +1,418 @@
+package org.qortal.api.resource;
+
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.Parameter;
+import io.swagger.v3.oas.annotations.media.ArraySchema;
+import io.swagger.v3.oas.annotations.media.Content;
+import io.swagger.v3.oas.annotations.media.Schema;
+import io.swagger.v3.oas.annotations.parameters.RequestBody;
+import io.swagger.v3.oas.annotations.responses.ApiResponse;
+import io.swagger.v3.oas.annotations.security.SecurityRequirement;
+import io.swagger.v3.oas.annotations.tags.Tag;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import java.util.Random;
+import java.util.function.Supplier;
+
+import javax.servlet.http.HttpServletRequest;
+import javax.ws.rs.DELETE;
+import javax.ws.rs.GET;
+import javax.ws.rs.Path;
+import javax.ws.rs.PathParam;
+import javax.ws.rs.QueryParam;
+import javax.ws.rs.core.Context;
+import javax.ws.rs.core.MediaType;
+
+import org.qortal.api.ApiError;
+import org.qortal.api.ApiErrors;
+import org.qortal.api.ApiExceptionFactory;
+import org.qortal.api.Security;
+import org.qortal.api.model.CrossChainCancelRequest;
+import org.qortal.api.model.CrossChainTradeSummary;
+import org.qortal.crosschain.SupportedBlockchain;
+import org.qortal.crosschain.ACCT;
+import org.qortal.crosschain.AcctMode;
+import org.qortal.crypto.Crypto;
+import org.qortal.data.at.ATData;
+import org.qortal.data.at.ATStateData;
+import org.qortal.data.crosschain.CrossChainTradeData;
+import org.qortal.data.transaction.BaseTransactionData;
+import org.qortal.data.transaction.MessageTransactionData;
+import org.qortal.data.transaction.TransactionData;
+import org.qortal.group.Group;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.repository.RepositoryManager;
+import org.qortal.transaction.MessageTransaction;
+import org.qortal.transaction.Transaction.ValidationResult;
+import org.qortal.transform.TransformationException;
+import org.qortal.transform.Transformer;
+import org.qortal.transform.transaction.MessageTransactionTransformer;
+import org.qortal.utils.Amounts;
+import org.qortal.utils.Base58;
+import org.qortal.utils.ByteArray;
+import org.qortal.utils.NTP;
+
+@Path("/crosschain")
+@Tag(name = "Cross-Chain")
+public class CrossChainResource {
+
+	@Context
+	HttpServletRequest request;
+
+	@GET
+	@Path("/tradeoffers")
+	@Operation(
+		summary = "Find cross-chain trade offers",
+		responses = {
+			@ApiResponse(
+				content = @Content(
+					array = @ArraySchema(
+						schema = @Schema(
+							implementation = CrossChainTradeData.class
+						)
+					)
+				)
+			)
+		}
+	)
+	@ApiErrors({ApiError.INVALID_CRITERIA, ApiError.REPOSITORY_ISSUE})
+	public List<CrossChainTradeData> getTradeOffers(
+			@Parameter(
+				description = "Limit to specific blockchain",
+				example = "LITECOIN",
+				schema = @Schema(implementation = SupportedBlockchain.class)
+			) @QueryParam("foreignBlockchain") SupportedBlockchain foreignBlockchain,
+			@Parameter( ref = "limit") @QueryParam("limit") Integer limit,
+			@Parameter( ref = "offset" ) @QueryParam("offset") Integer offset,
+			@Parameter( ref = "reverse" ) @QueryParam("reverse") Boolean reverse) {
+		// Impose a limit on 'limit'
+		if (limit != null && limit > 100)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+
+		final boolean isExecutable = true;
+		List<CrossChainTradeData> crossChainTradesData = new ArrayList<>();
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			Map<ByteArray, Supplier<ACCT>> acctsByCodeHash = SupportedBlockchain.getFilteredAcctMap(foreignBlockchain);
+
+			for (Map.Entry<ByteArray, Supplier<ACCT>> acctInfo : acctsByCodeHash.entrySet()) {
+				byte[] codeHash = acctInfo.getKey().value;
+				ACCT acct = acctInfo.getValue().get();
+
+				List<ATData> atsData = repository.getATRepository().getATsByFunctionality(codeHash, isExecutable, limit, offset, reverse);
+
+				for (ATData atData : atsData) {
+					CrossChainTradeData crossChainTradeData = acct.populateTradeData(repository, atData);
+					crossChainTradesData.add(crossChainTradeData);
+				}
+			}
+
+			return crossChainTradesData;
+		} catch (DataException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
+		}
+	}
+
+	@GET
+	@Path("/trade/{ataddress}")
+	@Operation(
+		summary = "Show detailed trade info",
+		responses = {
+			@ApiResponse(
+				content = @Content(
+					schema = @Schema(
+						implementation = CrossChainTradeData.class
+					)
+				)
+			)
+		}
+	)
+	@ApiErrors({ApiError.ADDRESS_UNKNOWN, ApiError.INVALID_CRITERIA, ApiError.REPOSITORY_ISSUE})
+	public CrossChainTradeData getTrade(@PathParam("ataddress") String atAddress) {
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			ATData atData = repository.getATRepository().fromATAddress(atAddress);
+			if (atData == null)
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.ADDRESS_UNKNOWN);
+
+			ACCT acct = SupportedBlockchain.getAcctByCodeHash(atData.getCodeHash());
+			if (acct == null)
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+
+			return acct.populateTradeData(repository, atData);
+		} catch (DataException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
+		}
+	}
+
+	@GET
+	@Path("/trades")
+	@Operation(
+		summary = "Find completed cross-chain trades",
+		description = "Returns summary info about successfully completed cross-chain trades",
+		responses = {
+			@ApiResponse(
+				content = @Content(
+					array = @ArraySchema(
+						schema = @Schema(
+							implementation = CrossChainTradeSummary.class
+						)
+					)
+				)
+			)
+		}
+	)
+	@ApiErrors({ApiError.INVALID_CRITERIA, ApiError.REPOSITORY_ISSUE})
+	public List<CrossChainTradeSummary> getCompletedTrades(
+			@Parameter(
+					description = "Limit to specific blockchain",
+					example = "LITECOIN",
+					schema = @Schema(implementation = SupportedBlockchain.class)
+				) @QueryParam("foreignBlockchain") SupportedBlockchain foreignBlockchain,
+			@Parameter(
+				description = "Only return trades that completed on/after this timestamp (milliseconds since epoch)",
+				example = "1597310000000"
+			) @QueryParam("minimumTimestamp") Long minimumTimestamp,
+			@Parameter( ref = "limit") @QueryParam("limit") Integer limit,
+			@Parameter( ref = "offset" ) @QueryParam("offset") Integer offset,
+			@Parameter( ref = "reverse" ) @QueryParam("reverse") Boolean reverse) {
+		// Impose a limit on 'limit'
+		if (limit != null && limit > 100)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+
+		// minimumTimestamp (if given) needs to be positive
+		if (minimumTimestamp != null && minimumTimestamp <= 0)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+
+		final Boolean isFinished = Boolean.TRUE;
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			Integer minimumFinalHeight = null;
+
+			if (minimumTimestamp != null) {
+				minimumFinalHeight = repository.getBlockRepository().getHeightFromTimestamp(minimumTimestamp);
+
+				if (minimumFinalHeight == 0)
+					// We don't have any blocks since minimumTimestamp, let alone trades, so nothing to return
+					return Collections.emptyList();
+
+				// height returned from repository is for block BEFORE timestamp
+				// but we want trades AFTER timestamp so bump height accordingly
+				minimumFinalHeight++;
+			}
+
+			List<CrossChainTradeSummary> crossChainTrades = new ArrayList<>();
+
+			Map<ByteArray, Supplier<ACCT>> acctsByCodeHash = SupportedBlockchain.getFilteredAcctMap(foreignBlockchain);
+
+			for (Map.Entry<ByteArray, Supplier<ACCT>> acctInfo : acctsByCodeHash.entrySet()) {
+				byte[] codeHash = acctInfo.getKey().value;
+				ACCT acct = acctInfo.getValue().get();
+
+				List<ATStateData> atStates = repository.getATRepository().getMatchingFinalATStates(codeHash,
+						isFinished, acct.getModeByteOffset(), (long) AcctMode.REDEEMED.value, minimumFinalHeight,
+						limit, offset, reverse);
+
+				for (ATStateData atState : atStates) {
+					CrossChainTradeData crossChainTradeData = acct.populateTradeData(repository, atState);
+
+					// We also need block timestamp for use as trade timestamp
+					long timestamp = repository.getBlockRepository().getTimestampFromHeight(atState.getHeight());
+
+					CrossChainTradeSummary crossChainTradeSummary = new CrossChainTradeSummary(crossChainTradeData, timestamp);
+					crossChainTrades.add(crossChainTradeSummary);
+				}
+			}
+
+			return crossChainTrades;
+		} catch (DataException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
+		}
+	}
+
+	@GET
+	@Path("/price/{blockchain}")
+	@Operation(
+		summary = "Request current estimated trading price",
+		description = "Returns price based on most recent completed trades. Price is expressed in terms of QORT per unit foreign currency.",
+		responses = {
+			@ApiResponse(
+				content = @Content(
+					schema = @Schema(
+						type = "number"
+					)
+				)
+			)
+		}
+	)
+	@ApiErrors({ApiError.INVALID_CRITERIA, ApiError.REPOSITORY_ISSUE})
+	public long getTradePriceEstimate(
+			@Parameter(
+					description = "foreign blockchain",
+					example = "LITECOIN",
+					schema = @Schema(implementation = SupportedBlockchain.class)
+				) @PathParam("blockchain") SupportedBlockchain foreignBlockchain) {
+		// foreignBlockchain is required
+		if (foreignBlockchain == null)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+
+		// We want both a minimum of 5 trades and enough trades to span at least 4 hours
+		int minimumCount = 5;
+		long minimumPeriod = 4 * 60 * 60 * 1000L; // ms
+		Boolean isFinished = Boolean.TRUE;
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			Map<ByteArray, Supplier<ACCT>> acctsByCodeHash = SupportedBlockchain.getFilteredAcctMap(foreignBlockchain);
+
+			long totalForeign = 0;
+			long totalQort = 0;
+
+			for (Map.Entry<ByteArray, Supplier<ACCT>> acctInfo : acctsByCodeHash.entrySet()) {
+				byte[] codeHash = acctInfo.getKey().value;
+				ACCT acct = acctInfo.getValue().get();
+
+				List<ATStateData> atStates = repository.getATRepository().getMatchingFinalATStatesQuorum(codeHash,
+						isFinished, acct.getModeByteOffset(), (long) AcctMode.REDEEMED.value, minimumCount, minimumPeriod);
+
+				for (ATStateData atState : atStates) {
+					CrossChainTradeData crossChainTradeData = acct.populateTradeData(repository, atState);
+					totalForeign += crossChainTradeData.expectedForeignAmount;
+					totalQort += crossChainTradeData.qortAmount;
+				}
+			}
+
+			return Amounts.scaledDivide(totalQort, totalForeign);
+		} catch (DataException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
+		}
+	}
+
+	@DELETE
+	@Path("/tradeoffer")
+	@Operation(
+		summary = "Builds raw, unsigned 'cancel' MESSAGE transaction that cancels cross-chain trade offer",
+		description = "Specify address of cross-chain AT that needs to be cancelled.<br>"
+			+ "AT needs to be in 'offer' mode. Messages sent to an AT in 'trade' mode will be ignored.<br>"
+			+ "Performs MESSAGE proof-of-work.<br>"
+			+ "You need to sign output with AT creator's private key otherwise the MESSAGE transaction will be invalid.",
+		requestBody = @RequestBody(
+			required = true,
+			content = @Content(
+				mediaType = MediaType.APPLICATION_JSON,
+				schema = @Schema(
+					implementation = CrossChainCancelRequest.class
+				)
+			)
+		),
+		responses = {
+			@ApiResponse(
+				content = @Content(
+					schema = @Schema(
+						type = "string"
+					)
+				)
+			)
+		}
+	)
+	@ApiErrors({ApiError.INVALID_PUBLIC_KEY, ApiError.INVALID_ADDRESS, ApiError.INVALID_CRITERIA, ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
+	public String cancelTrade(CrossChainCancelRequest cancelRequest) {
+		Security.checkApiCallAllowed(request);
+
+		byte[] creatorPublicKey = cancelRequest.creatorPublicKey;
+
+		if (creatorPublicKey == null || creatorPublicKey.length != Transformer.PUBLIC_KEY_LENGTH)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_PUBLIC_KEY);
+
+		if (cancelRequest.atAddress == null || !Crypto.isValidAtAddress(cancelRequest.atAddress))
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_ADDRESS);
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			ATData atData = fetchAtDataWithChecking(repository, cancelRequest.atAddress);
+
+			ACCT acct = SupportedBlockchain.getAcctByCodeHash(atData.getCodeHash());
+			if (acct == null)
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_ADDRESS);
+
+			CrossChainTradeData crossChainTradeData = acct.populateTradeData(repository, atData);
+
+			if (crossChainTradeData.mode != AcctMode.OFFERING)
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+
+			// Does supplied public key match AT creator's public key?
+			if (!Arrays.equals(creatorPublicKey, atData.getCreatorPublicKey()))
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_PUBLIC_KEY);
+
+			// Good to make MESSAGE
+
+			String atCreatorAddress = Crypto.toAddress(creatorPublicKey);
+			byte[] messageData = acct.buildCancelMessage(atCreatorAddress);
+
+			byte[] messageTransactionBytes = buildAtMessage(repository, creatorPublicKey, cancelRequest.atAddress, messageData);
+
+			return Base58.encode(messageTransactionBytes);
+		} catch (DataException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
+		}
+	}
+
+	private ATData fetchAtDataWithChecking(Repository repository, String atAddress) throws DataException {
+		ATData atData = repository.getATRepository().fromATAddress(atAddress);
+		if (atData == null)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.ADDRESS_UNKNOWN);
+
+		// No point sending message to AT that's finished
+		if (atData.getIsFinished())
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA);
+
+		return atData;
+	}
+
+	private byte[] buildAtMessage(Repository repository, byte[] senderPublicKey, String atAddress, byte[] messageData) throws DataException {
+		long txTimestamp = NTP.getTime();
+
+		// senderPublicKey could be ephemeral trade public key where there is no corresponding account and hence no reference
+		String senderAddress = Crypto.toAddress(senderPublicKey);
+		byte[] lastReference = repository.getAccountRepository().getLastReference(senderAddress);
+		final boolean requiresPoW = lastReference == null;
+
+		if (requiresPoW) {
+			Random random = new Random();
+			lastReference = new byte[Transformer.SIGNATURE_LENGTH];
+			random.nextBytes(lastReference);
+		}
+
+		int version = 4;
+		int nonce = 0;
+		long amount = 0L;
+		Long assetId = null; // no assetId as amount is zero
+		Long fee = 0L;
+
+		BaseTransactionData baseTransactionData = new BaseTransactionData(txTimestamp, Group.NO_GROUP, lastReference, senderPublicKey, fee, null);
+		TransactionData messageTransactionData = new MessageTransactionData(baseTransactionData, version, nonce, atAddress, amount, assetId, messageData, false, false);
+
+		MessageTransaction messageTransaction = new MessageTransaction(repository, messageTransactionData);
+
+		if (requiresPoW) {
+			messageTransaction.computeNonce();
+		} else {
+			fee = messageTransaction.calcRecommendedFee();
+			messageTransactionData.setFee(fee);
+		}
+
+		ValidationResult result = messageTransaction.isValidUnconfirmed();
+		if (result != ValidationResult.OK)
+			throw TransactionsResource.createTransactionInvalidException(request, result);
+
+		try {
+			return MessageTransactionTransformer.toBytes(messageTransactionData);
+		} catch (TransformationException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.TRANSFORMATION_ERROR, e);
+		}
+	}
+
+}

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

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

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

@@ -6,8 +6,12 @@ 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.security.SecurityRequirement;
 import io.swagger.v3.oas.annotations.tags.Tag;
 
+import java.net.InetSocketAddress;
+import java.net.UnknownHostException;
+import java.util.ArrayList;
 import java.util.List;
 import java.util.stream.Collectors;
 
@@ -25,12 +29,19 @@ import org.qortal.api.ApiException;
 import org.qortal.api.ApiExceptionFactory;
 import org.qortal.api.Security;
 import org.qortal.api.model.ConnectedPeer;
+import org.qortal.controller.Controller;
+import org.qortal.controller.Synchronizer;
+import org.qortal.controller.Synchronizer.SynchronizationResult;
+import org.qortal.data.block.BlockSummaryData;
 import org.qortal.data.network.PeerData;
 import org.qortal.network.Network;
+import org.qortal.network.Peer;
 import org.qortal.network.PeerAddress;
 import org.qortal.repository.DataException;
 import org.qortal.repository.Repository;
 import org.qortal.repository.RepositoryManager;
+import org.qortal.utils.ExecuteProduceConsume;
+import org.qortal.utils.NTP;
 
 @Path("/peers")
 @Tag(name = "Peers")
@@ -80,11 +91,7 @@ public class PeersResource {
 		ApiError.REPOSITORY_ISSUE
 	})
 	public List<PeerData> getKnownPeers() {
-		try (final Repository repository = RepositoryManager.getRepository()) {
-			return repository.getNetworkRepository().getAllPeers();
-		} catch (DataException e) {
-			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
-		}
+		return Network.getInstance().getAllKnownPeers();
 	}
 
 	@GET
@@ -108,6 +115,30 @@ public class PeersResource {
 		return Network.getInstance().getSelfPeers();
 	}
 
+	@GET
+	@Path("/enginestats")
+	@Operation(
+		summary = "Fetch statistics snapshot for networking engine",
+		responses = {
+			@ApiResponse(
+				content = @Content(
+					mediaType = MediaType.APPLICATION_JSON,
+					array = @ArraySchema(
+						schema = @Schema(
+							implementation = ExecuteProduceConsume.StatsSnapshot.class
+						)
+					)
+				)
+			)
+		}
+	)
+	@SecurityRequirement(name = "apiKey")
+	public ExecuteProduceConsume.StatsSnapshot getEngineStats() {
+		Security.checkApiCallAllowed(request);
+
+		return Network.getInstance().getStatsSnapshot();
+	}
+
 	@POST
 	@Operation(
 		summary = "Add new peer address",
@@ -139,21 +170,25 @@ public class PeersResource {
 	@ApiErrors({
 		ApiError.INVALID_NETWORK_ADDRESS, ApiError.REPOSITORY_ISSUE
 	})
+	@SecurityRequirement(name = "apiKey")
 	public String addPeer(String address) {
 		Security.checkApiCallAllowed(request);
 
-		try (final Repository repository = RepositoryManager.getRepository()) {
+		final Long addedWhen = NTP.getTime();
+		if (addedWhen == null)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.NO_TIME_SYNC);
+
+		try {
 			PeerAddress peerAddress = PeerAddress.fromString(address);
 
-			PeerData peerData = new PeerData(peerAddress, System.currentTimeMillis(), "API");
-			repository.getNetworkRepository().save(peerData);
-			repository.saveChanges();
+			List<PeerAddress> newPeerAddresses = new ArrayList<>(1);
+			newPeerAddresses.add(peerAddress);
 
-			return "true";
+			boolean addResult = Network.getInstance().mergePeers("API", addedWhen, newPeerAddresses);
+
+			return addResult ? "true" : "false";
 		} catch (IllegalArgumentException e) {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_NETWORK_ADDRESS);
-		} catch (ApiException e) {
-			throw e;
 		} catch (DataException e) {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
 		}
@@ -190,6 +225,7 @@ public class PeersResource {
 	@ApiErrors({
 		ApiError.INVALID_NETWORK_ADDRESS, ApiError.REPOSITORY_ISSUE
 	})
+	@SecurityRequirement(name = "apiKey")
 	public String removePeer(String address) {
 		Security.checkApiCallAllowed(request);
 
@@ -225,6 +261,7 @@ public class PeersResource {
 	@ApiErrors({
 		ApiError.REPOSITORY_ISSUE
 	})
+	@SecurityRequirement(name = "apiKey")
 	public String removeKnownPeers(String address) {
 		Security.checkApiCallAllowed(request);
 
@@ -237,4 +274,68 @@ public class PeersResource {
 		}
 	}
 
+	@POST
+	@Path("/commonblock")
+	@Operation(
+		summary = "Report common block with given peer.",
+		requestBody = @RequestBody(
+			required = true,
+			content = @Content(
+				mediaType = MediaType.TEXT_PLAIN,
+				schema = @Schema(
+					type = "string", example = "node2.qortal.org"
+				)
+			)
+		),
+		responses = {
+			@ApiResponse(
+				description = "the block",
+				content = @Content(
+					array = @ArraySchema(
+						schema = @Schema(
+							implementation = BlockSummaryData.class
+						)
+					)
+				)
+			)
+		}
+	)
+	@ApiErrors({ApiError.INVALID_DATA, ApiError.REPOSITORY_ISSUE})
+	@SecurityRequirement(name = "apiKey")
+	public List<BlockSummaryData> commonBlock(String targetPeerAddress) {
+		Security.checkApiCallAllowed(request);
+
+		try {
+			// Try to resolve passed address to make things easier
+			PeerAddress peerAddress = PeerAddress.fromString(targetPeerAddress);
+			InetSocketAddress resolvedAddress = peerAddress.toSocketAddress();
+
+			List<Peer> peers = Network.getInstance().getHandshakedPeers();
+			Peer targetPeer = peers.stream().filter(peer -> peer.getResolvedAddress().equals(resolvedAddress)).findFirst().orElse(null);
+
+			if (targetPeer == null)
+				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_DATA);
+
+			try (final Repository repository = RepositoryManager.getRepository()) {
+				int ourInitialHeight = Controller.getInstance().getChainHeight();
+				boolean force = true;
+				List<BlockSummaryData> peerBlockSummaries = new ArrayList<>();
+
+				SynchronizationResult findCommonBlockResult = Synchronizer.getInstance().fetchSummariesFromCommonBlock(repository, targetPeer, ourInitialHeight, force, peerBlockSummaries);
+				if (findCommonBlockResult != SynchronizationResult.OK)
+					return null;
+
+				return peerBlockSummaries;
+			}
+		} catch (IllegalArgumentException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_DATA);
+		} catch (UnknownHostException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_DATA);
+		} catch (DataException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
+		} catch (InterruptedException e) {
+			return null;
+		}
+	}
+
 }

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

@@ -363,6 +363,60 @@ public class TransactionsResource {
 		}
 	}
 
+	@GET
+	@Path("/creator/{publickey}")
+	@Operation(
+		summary = "Find matching transactions created by account with given public key",
+		responses = {
+			@ApiResponse(
+				description = "transactions",
+				content = @Content(
+					array = @ArraySchema(
+						schema = @Schema(
+							implementation = TransactionData.class
+						)
+					)
+				)
+			)
+		}
+	)
+	@ApiErrors({
+		ApiError.INVALID_CRITERIA, ApiError.REPOSITORY_ISSUE
+	})
+	public List<TransactionData> findCreatorsTransactions(@PathParam("publickey") String publicKey58,
+			@Parameter(
+				description = "whether to include confirmed, unconfirmed or both",
+				required = true
+			) @QueryParam("confirmationStatus") ConfirmationStatus confirmationStatus, @Parameter(
+				ref = "limit"
+			) @QueryParam("limit") Integer limit, @Parameter(
+				ref = "offset"
+			) @QueryParam("offset") Integer offset, @Parameter(
+				ref = "reverse"
+			) @QueryParam("reverse") Boolean reverse) {
+		// Decode public key
+		byte[] publicKey;
+		try {
+			publicKey = Base58.decode(publicKey58);
+		} catch (NumberFormatException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_PUBLIC_KEY, e);
+		}
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			List<byte[]> signatures = repository.getTransactionRepository().getSignaturesMatchingCriteria(null,
+					publicKey, confirmationStatus, limit, offset, reverse);
+
+			// Expand signatures to transactions
+			List<TransactionData> transactions = new ArrayList<>(signatures.size());
+			for (byte[] signature : signatures)
+				transactions.add(repository.getTransactionRepository().fromSignature(signature));
+
+			return transactions;
+		} catch (DataException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
+		}
+	}
+
 	@POST
 	@Path("/sign")
 	@Operation(
@@ -456,41 +510,39 @@ public class TransactionsResource {
 		if (!Controller.getInstance().isUpToDate())
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.BLOCKCHAIN_NEEDS_SYNC);
 
+		byte[] rawBytes = Base58.decode(rawBytes58);
+
+		TransactionData transactionData;
+		try {
+			transactionData = TransactionTransformer.fromBytes(rawBytes);
+		} catch (TransformationException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.TRANSFORMATION_ERROR, e);
+		}
+
+		if (transactionData == null)
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_DATA);
+
 		try (final Repository repository = RepositoryManager.getRepository()) {
-			byte[] rawBytes = Base58.decode(rawBytes58);
-
-			TransactionData transactionData = TransactionTransformer.fromBytes(rawBytes);
-
-			if (transactionData == null)
-				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_DATA);
-
 			Transaction transaction = Transaction.fromData(repository, transactionData);
 
 			if (!transaction.isSignatureValid())
 				throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_SIGNATURE);
 
 			ReentrantLock blockchainLock = Controller.getInstance().getBlockchainLock();
-			if (!blockchainLock.tryLock(500, TimeUnit.MILLISECONDS))
+			if (!blockchainLock.tryLock(30, TimeUnit.SECONDS))
 				throw createTransactionInvalidException(request, ValidationResult.NO_BLOCKCHAIN_LOCK);
 
 			try {
 				ValidationResult result = transaction.importAsUnconfirmed();
 				if (result != ValidationResult.OK)
 					throw createTransactionInvalidException(request, result);
-
-				// Notify controller of new transaction
-				Controller.getInstance().onNewTransaction(transactionData);
-
-				return "true";
 			} finally {
 				blockchainLock.unlock();
 			}
+
+			return "true";
 		} catch (NumberFormatException e) {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_DATA, e);
-		} catch (TransformationException e) {
-			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.TRANSFORMATION_ERROR, e);
-		} catch (ApiException e) {
-			throw e;
 		} catch (DataException e) {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
 		} catch (InterruptedException e) {
@@ -573,7 +625,7 @@ public class TransactionsResource {
 
 	public static ApiException createTransactionInvalidException(HttpServletRequest request, ValidationResult result) {
 		String translatedResult = Translator.INSTANCE.translate("TransactionValidity", request.getLocale().getLanguage(), result.name());
-		return ApiExceptionFactory.INSTANCE.createException(request, ApiError.TRANSACTION_INVALID, null, translatedResult);
+		return ApiExceptionFactory.INSTANCE.createException(request, ApiError.TRANSACTION_INVALID, null, translatedResult, result.name());
 	}
 
 }

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

@@ -0,0 +1,96 @@
+package org.qortal.api.websocket;
+
+import java.io.IOException;
+import java.io.StringWriter;
+import java.util.Map;
+import java.util.concurrent.atomic.AtomicReference;
+
+import org.eclipse.jetty.websocket.api.Session;
+import org.eclipse.jetty.websocket.api.WebSocketException;
+import org.eclipse.jetty.websocket.api.annotations.OnWebSocketClose;
+import org.eclipse.jetty.websocket.api.annotations.OnWebSocketConnect;
+import org.eclipse.jetty.websocket.api.annotations.OnWebSocketError;
+import org.eclipse.jetty.websocket.api.annotations.OnWebSocketMessage;
+import org.eclipse.jetty.websocket.api.annotations.WebSocket;
+import org.eclipse.jetty.websocket.servlet.WebSocketServletFactory;
+import org.qortal.controller.ChatNotifier;
+import org.qortal.crypto.Crypto;
+import org.qortal.data.chat.ActiveChats;
+import org.qortal.data.transaction.ChatTransactionData;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.repository.RepositoryManager;
+
+@WebSocket
+@SuppressWarnings("serial")
+public class ActiveChatsWebSocket extends ApiWebSocket {
+
+	@Override
+	public void configure(WebSocketServletFactory factory) {
+		factory.register(ActiveChatsWebSocket.class);
+	}
+
+	@OnWebSocketConnect
+	@Override
+	public void onWebSocketConnect(Session session) {
+		Map<String, String> pathParams = getPathParams(session, "/{address}");
+
+		String address = pathParams.get("address");
+		if (address == null || !Crypto.isValidAddress(address)) {
+			session.close(4001, "invalid address");
+			return;
+		}
+
+		AtomicReference<String> previousOutput = new AtomicReference<>(null);
+
+		ChatNotifier.Listener listener = chatTransactionData -> onNotify(session, chatTransactionData, address, previousOutput);
+		ChatNotifier.getInstance().register(session, listener);
+
+		this.onNotify(session, null, address, previousOutput);
+	}
+
+	@OnWebSocketClose
+	@Override
+	public void onWebSocketClose(Session session, int statusCode, String reason) {
+		ChatNotifier.getInstance().deregister(session);
+	}
+
+	@OnWebSocketError
+	public void onWebSocketError(Session session, Throwable throwable) {
+		/* ignored */
+	}
+
+	@OnWebSocketMessage
+	public void onWebSocketMessage(Session session, String message) {
+		/* ignored */
+	}
+
+	private void onNotify(Session session, ChatTransactionData chatTransactionData, String ourAddress, AtomicReference<String> previousOutput) {
+		// If CHAT has a recipient (i.e. direct message, not group-based) and we're neither sender nor recipient, then it's of no interest
+		if (chatTransactionData != null) {
+			String recipient = chatTransactionData.getRecipient();
+
+			if (recipient != null && (!recipient.equals(ourAddress) && !chatTransactionData.getSender().equals(ourAddress)))
+				return;
+		}
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			ActiveChats activeChats = repository.getChatRepository().getActiveChats(ourAddress);
+
+			StringWriter stringWriter = new StringWriter();
+
+			marshall(stringWriter, activeChats);
+
+			// Only output if something has changed
+			String output = stringWriter.toString();
+			if (output.equals(previousOutput.get()))
+				return;
+
+			previousOutput.set(output);
+			session.getRemote().sendStringByFuture(output);
+		} catch (DataException | IOException | WebSocketException e) {
+			// No output this time?
+		}
+	}
+
+}

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

@@ -0,0 +1,101 @@
+package org.qortal.api.websocket;
+
+import java.io.IOException;
+import java.io.StringWriter;
+import java.util.concurrent.atomic.AtomicReference;
+
+import org.eclipse.jetty.websocket.api.Session;
+import org.eclipse.jetty.websocket.api.WebSocketException;
+import org.eclipse.jetty.websocket.api.annotations.OnWebSocketClose;
+import org.eclipse.jetty.websocket.api.annotations.OnWebSocketConnect;
+import org.eclipse.jetty.websocket.api.annotations.OnWebSocketError;
+import org.eclipse.jetty.websocket.api.annotations.OnWebSocketMessage;
+import org.eclipse.jetty.websocket.api.annotations.WebSocket;
+import org.eclipse.jetty.websocket.servlet.WebSocketServletFactory;
+import org.qortal.api.model.NodeStatus;
+import org.qortal.controller.Controller;
+import org.qortal.event.Event;
+import org.qortal.event.EventBus;
+import org.qortal.event.Listener;
+
+@WebSocket
+@SuppressWarnings("serial")
+public class AdminStatusWebSocket extends ApiWebSocket implements Listener {
+
+	private static final AtomicReference<String> previousOutput = new AtomicReference<>(null);
+
+	@Override
+	public void configure(WebSocketServletFactory factory) {
+		factory.register(AdminStatusWebSocket.class);
+
+		try {
+			previousOutput.set(buildStatusString());
+		} catch (IOException e) {
+			// How to fail properly?
+			return;
+		}
+
+		EventBus.INSTANCE.addListener(this::listen);
+	}
+
+	@Override
+	public void listen(Event event) {
+		if (!(event instanceof Controller.StatusChangeEvent))
+			return;
+
+		String newOutput;
+		try {
+			newOutput = buildStatusString();
+		} catch (IOException e) {
+			// Ignore this time?
+			return;
+		}
+
+		if (previousOutput.getAndUpdate(currentValue -> newOutput).equals(newOutput))
+			// Output hasn't changed, so don't send anything
+			return;
+
+		for (Session session : getSessions())
+			this.sendStatus(session, newOutput);
+	}
+
+	@OnWebSocketConnect
+	@Override
+	public void onWebSocketConnect(Session session) {
+		this.sendStatus(session, previousOutput.get());
+
+		super.onWebSocketConnect(session);
+	}
+
+	@OnWebSocketClose
+	@Override
+	public void onWebSocketClose(Session session, int statusCode, String reason) {
+		super.onWebSocketClose(session, statusCode, reason);
+	}
+
+	@OnWebSocketError
+	public void onWebSocketError(Session session, Throwable throwable) {
+		/* We ignore errors for now, but method here to silence log spam */
+	}
+
+	@OnWebSocketMessage
+	public void onWebSocketMessage(Session session, String message) {
+		/* ignored */
+	}
+
+	private static String buildStatusString() throws IOException {
+		NodeStatus nodeStatus = new NodeStatus();
+		StringWriter stringWriter = new StringWriter();
+		marshall(stringWriter, nodeStatus);
+		return stringWriter.toString();
+	}
+
+	private void sendStatus(Session session, String status) {
+		try {
+			session.getRemote().sendStringByFuture(status);
+		} catch (WebSocketException e) {
+			// No output this time?
+		}
+	}
+
+}

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

@@ -0,0 +1,122 @@
+package org.qortal.api.websocket;
+
+import java.io.IOException;
+import java.io.StringWriter;
+import java.io.Writer;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import javax.xml.bind.JAXBContext;
+import javax.xml.bind.JAXBException;
+import javax.xml.bind.Marshaller;
+
+import org.eclipse.jetty.http.pathmap.UriTemplatePathSpec;
+import org.eclipse.jetty.websocket.api.Session;
+import org.eclipse.jetty.websocket.servlet.ServletUpgradeRequest;
+import org.eclipse.jetty.websocket.servlet.WebSocketServlet;
+import org.eclipse.persistence.jaxb.JAXBContextFactory;
+import org.eclipse.persistence.jaxb.MarshallerProperties;
+import org.qortal.api.ApiError;
+import org.qortal.api.ApiErrorRoot;
+
+@SuppressWarnings("serial")
+abstract class ApiWebSocket extends WebSocketServlet {
+
+	private static final Map<Class<? extends ApiWebSocket>, List<Session>> SESSIONS_BY_CLASS = new HashMap<>();
+
+	protected static String getPathInfo(Session session) {
+		ServletUpgradeRequest upgradeRequest = (ServletUpgradeRequest) session.getUpgradeRequest();
+		return upgradeRequest.getHttpServletRequest().getPathInfo();
+	}
+
+	protected static Map<String, String> getPathParams(Session session, String pathSpec) {
+		UriTemplatePathSpec uriTemplatePathSpec = new UriTemplatePathSpec(pathSpec);
+		return uriTemplatePathSpec.getPathParams(getPathInfo(session));
+	}
+
+	protected static void sendError(Session session, ApiError apiError) {
+		ApiErrorRoot apiErrorRoot = new ApiErrorRoot();
+		apiErrorRoot.setApiError(apiError);
+
+		StringWriter stringWriter = new StringWriter();
+		try {
+			marshall(stringWriter, apiErrorRoot);
+			session.getRemote().sendString(stringWriter.toString());
+		} catch (IOException e) {
+			// Remote end probably closed
+		}
+	}
+
+	protected 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 websocket", e);
+		}
+	}
+
+	protected static void marshall(Writer writer, Collection<?> collection) throws IOException {
+		// If collection is empty then we're returning "[]" anyway
+		if (collection.isEmpty()) {
+			writer.append("[]");
+			return;
+		}
+
+		// Grab an entry from collection so we can determine type
+		Object entry = collection.iterator().next();
+
+		Marshaller marshaller = createMarshaller(entry.getClass());
+
+		try {
+			marshaller.marshal(collection, writer);
+		} catch (JAXBException e) {
+			throw new IOException("Unable to create marshall object for websocket", e);
+		}
+	}
+
+	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 websocket marshaller", e);
+		}
+	}
+
+	public void onWebSocketConnect(Session session) {
+		synchronized (SESSIONS_BY_CLASS) {
+			SESSIONS_BY_CLASS.computeIfAbsent(this.getClass(), clazz -> new ArrayList<>()).add(session);
+		}
+	}
+
+	public void onWebSocketClose(Session session, int statusCode, String reason) {
+		synchronized (SESSIONS_BY_CLASS) {
+			List<Session> sessions = SESSIONS_BY_CLASS.get(this.getClass());
+			if (sessions != null)
+				sessions.remove(session);
+		}
+	}
+
+	protected List<Session> getSessions() {
+		synchronized (SESSIONS_BY_CLASS) {
+			return new ArrayList<>(SESSIONS_BY_CLASS.get(this.getClass()));
+		}
+	}
+
+}

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

@@ -0,0 +1,141 @@
+package org.qortal.api.websocket;
+
+import java.io.IOException;
+import java.io.StringWriter;
+import java.util.List;
+
+import org.eclipse.jetty.websocket.api.Session;
+import org.eclipse.jetty.websocket.api.WebSocketException;
+import org.eclipse.jetty.websocket.api.annotations.OnWebSocketClose;
+import org.eclipse.jetty.websocket.api.annotations.OnWebSocketConnect;
+import org.eclipse.jetty.websocket.api.annotations.OnWebSocketError;
+import org.eclipse.jetty.websocket.api.annotations.OnWebSocketMessage;
+import org.eclipse.jetty.websocket.api.annotations.WebSocket;
+import org.eclipse.jetty.websocket.servlet.WebSocketServletFactory;
+import org.qortal.api.ApiError;
+import org.qortal.controller.Controller;
+import org.qortal.data.block.BlockData;
+import org.qortal.data.block.BlockSummaryData;
+import org.qortal.event.Event;
+import org.qortal.event.EventBus;
+import org.qortal.event.Listener;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.repository.RepositoryManager;
+import org.qortal.utils.Base58;
+
+@WebSocket
+@SuppressWarnings("serial")
+public class BlocksWebSocket extends ApiWebSocket implements Listener {
+
+	@Override
+	public void configure(WebSocketServletFactory factory) {
+		factory.register(BlocksWebSocket.class);
+
+		EventBus.INSTANCE.addListener(this::listen);
+	}
+
+	@Override
+	public void listen(Event event) {
+		if (!(event instanceof Controller.NewBlockEvent))
+			return;
+
+		BlockData blockData = ((Controller.NewBlockEvent) event).getBlockData();
+		BlockSummaryData blockSummary = new BlockSummaryData(blockData);
+
+		for (Session session : getSessions())
+			sendBlockSummary(session, blockSummary);
+	}
+
+	@OnWebSocketConnect
+	@Override
+	public void onWebSocketConnect(Session session) {
+		super.onWebSocketConnect(session);
+	}
+
+	@OnWebSocketClose
+	@Override
+	public void onWebSocketClose(Session session, int statusCode, String reason) {
+		super.onWebSocketClose(session, statusCode, reason);
+	}
+
+	@OnWebSocketError
+	public void onWebSocketError(Session session, Throwable throwable) {
+		/* We ignore errors for now, but method here to silence log spam */
+	}
+
+	@OnWebSocketMessage
+	public void onWebSocketMessage(Session session, String message) {
+		// We're expecting either a base58 block signature or an integer block height
+		if (message.length() > 128) {
+			// Try base58 block signature
+			byte[] signature;
+
+			try {
+				signature = Base58.decode(message);
+			} catch (NumberFormatException e) {
+				sendError(session, ApiError.INVALID_SIGNATURE);
+				return;
+			}
+
+			try (final Repository repository = RepositoryManager.getRepository()) {
+				int height = repository.getBlockRepository().getHeightFromSignature(signature);
+				if (height == 0) {
+					sendError(session, ApiError.BLOCK_UNKNOWN);
+					return;
+				}
+
+				List<BlockSummaryData> blockSummaries = repository.getBlockRepository().getBlockSummaries(height, height);
+				if (blockSummaries == null || blockSummaries.isEmpty()) {
+					sendError(session, ApiError.BLOCK_UNKNOWN);
+					return;
+				}
+
+				sendBlockSummary(session, blockSummaries.get(0));
+			} catch (DataException e) {
+				sendError(session, ApiError.REPOSITORY_ISSUE);
+			}
+
+			return;
+		}
+
+		if (message.length() > 10)
+			// Bigger than max integer value, so probably a ping - silently ignore
+			return;
+
+		// Try integer
+		int height;
+
+		try {
+			height = Integer.parseInt(message);
+		} catch (NumberFormatException e) {
+			sendError(session, ApiError.INVALID_HEIGHT);
+			return;
+		}
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			List<BlockSummaryData> blockSummaries = repository.getBlockRepository().getBlockSummaries(height, height);
+			if (blockSummaries == null || blockSummaries.isEmpty()) {
+				sendError(session, ApiError.BLOCK_UNKNOWN);
+				return;
+			}
+
+			sendBlockSummary(session, blockSummaries.get(0));
+		} catch (DataException e) {
+			sendError(session, ApiError.REPOSITORY_ISSUE);
+		}
+	}
+
+	private void sendBlockSummary(Session session, BlockSummaryData blockSummary) {
+		StringWriter stringWriter = new StringWriter();
+
+		try {
+			marshall(stringWriter, blockSummary);
+
+			session.getRemote().sendStringByFuture(stringWriter.toString());
+		} catch (IOException | WebSocketException e) {
+			// No output this time
+		}
+	}
+
+}

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

@@ -0,0 +1,156 @@
+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 org.eclipse.jetty.websocket.api.Session;
+import org.eclipse.jetty.websocket.api.WebSocketException;
+import org.eclipse.jetty.websocket.api.annotations.OnWebSocketClose;
+import org.eclipse.jetty.websocket.api.annotations.OnWebSocketConnect;
+import org.eclipse.jetty.websocket.api.annotations.OnWebSocketError;
+import org.eclipse.jetty.websocket.api.annotations.OnWebSocketMessage;
+import org.eclipse.jetty.websocket.api.annotations.WebSocket;
+import org.eclipse.jetty.websocket.servlet.WebSocketServletFactory;
+import org.qortal.controller.ChatNotifier;
+import org.qortal.data.chat.ChatMessage;
+import org.qortal.data.transaction.ChatTransactionData;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.repository.RepositoryManager;
+
+@WebSocket
+@SuppressWarnings("serial")
+public class ChatMessagesWebSocket extends ApiWebSocket {
+
+	@Override
+	public void configure(WebSocketServletFactory factory) {
+		factory.register(ChatMessagesWebSocket.class);
+	}
+
+	@OnWebSocketConnect
+	@Override
+	public void onWebSocketConnect(Session session) {
+		Map<String, List<String>> queryParams = session.getUpgradeRequest().getParameterMap();
+
+		List<String> txGroupIds = queryParams.get("txGroupId");
+		if (txGroupIds != null && txGroupIds.size() == 1) {
+			int txGroupId = Integer.parseInt(txGroupIds.get(0));
+
+			try (final Repository repository = RepositoryManager.getRepository()) {
+				List<ChatMessage> chatMessages = repository.getChatRepository().getMessagesMatchingCriteria(
+						null,
+						null,
+						txGroupId,
+						null,
+						null, null, null);
+
+				sendMessages(session, chatMessages);
+			} catch (DataException e) {
+				// Not a good start
+				session.close(4001, "Couldn't fetch initial messages from repository");
+				return;
+			}
+
+			ChatNotifier.Listener listener = chatTransactionData -> onNotify(session, chatTransactionData, txGroupId);
+			ChatNotifier.getInstance().register(session, listener);
+
+			return;
+		}
+
+		List<String> involvingAddresses = queryParams.get("involving");
+		if (involvingAddresses == null || involvingAddresses.size() != 2) {
+			session.close(4001, "invalid criteria");
+			return;
+		}
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			List<ChatMessage> chatMessages = repository.getChatRepository().getMessagesMatchingCriteria(
+					null,
+					null,
+					null,
+					involvingAddresses,
+					null, null, null);
+
+			sendMessages(session, chatMessages);
+		} catch (DataException e) {
+			// Not a good start
+			session.close(4001, "Couldn't fetch initial messages from repository");
+			return;
+		}
+
+		ChatNotifier.Listener listener = chatTransactionData -> onNotify(session, chatTransactionData, involvingAddresses);
+		ChatNotifier.getInstance().register(session, listener);
+	}
+
+	@OnWebSocketClose
+	@Override
+	public void onWebSocketClose(Session session, int statusCode, String reason) {
+		ChatNotifier.getInstance().deregister(session);
+	}
+
+	@OnWebSocketError
+	public void onWebSocketError(Session session, Throwable throwable) {
+		/* ignored */
+	}
+
+	@OnWebSocketMessage
+	public void onWebSocketMessage(Session session, String message) {
+		/* ignored */
+	}
+
+	private void onNotify(Session session, ChatTransactionData chatTransactionData, int txGroupId) {
+		if (chatTransactionData == null)
+			// There has been a group-membership change, but we're not interested
+			return;
+
+		// We only want group-based messages with our txGroupId
+		if (chatTransactionData.getRecipient() != null || chatTransactionData.getTxGroupId() != txGroupId)
+			return;
+
+		sendChat(session, chatTransactionData);
+	}
+
+	private void onNotify(Session session, ChatTransactionData chatTransactionData, List<String> involvingAddresses) {
+		// We only want direct/non-group messages where sender/recipient match our addresses
+		String recipient = chatTransactionData.getRecipient();
+		if (recipient == null)
+			return;
+
+		List<String> transactionAddresses = Arrays.asList(recipient, chatTransactionData.getSender());
+
+		if (!transactionAddresses.containsAll(involvingAddresses))
+			return;
+
+		sendChat(session, chatTransactionData);
+	}
+
+	private void sendMessages(Session session, List<ChatMessage> chatMessages) {
+		StringWriter stringWriter = new StringWriter();
+
+		try {
+			marshall(stringWriter, chatMessages);
+
+			session.getRemote().sendStringByFuture(stringWriter.toString());
+		} catch (IOException | WebSocketException e) {
+			// No output this time?
+		}
+	}
+
+	private void sendChat(Session session, ChatTransactionData chatTransactionData) {
+		// Convert ChatTransactionData to ChatMessage
+		ChatMessage chatMessage;
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			chatMessage = repository.getChatRepository().toChatMessage(chatTransactionData);
+		} catch (DataException e) {
+			// No output this time?
+			return;
+		}
+
+		sendMessages(session, Collections.singletonList(chatMessage));
+	}
+
+}

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

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

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

@@ -0,0 +1,157 @@
+package org.qortal.api.websocket;
+
+import java.io.IOException;
+import java.io.StringWriter;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+import org.eclipse.jetty.websocket.api.Session;
+import org.eclipse.jetty.websocket.api.annotations.OnWebSocketClose;
+import org.eclipse.jetty.websocket.api.annotations.OnWebSocketConnect;
+import org.eclipse.jetty.websocket.api.annotations.OnWebSocketError;
+import org.eclipse.jetty.websocket.api.annotations.OnWebSocketMessage;
+import org.eclipse.jetty.websocket.api.annotations.WebSocket;
+import org.eclipse.jetty.websocket.servlet.WebSocketServletFactory;
+import org.qortal.controller.tradebot.TradeBot;
+import org.qortal.crosschain.SupportedBlockchain;
+import org.qortal.data.crosschain.TradeBotData;
+import org.qortal.event.Event;
+import org.qortal.event.EventBus;
+import org.qortal.event.Listener;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.repository.RepositoryManager;
+import org.qortal.utils.Base58;
+
+@WebSocket
+@SuppressWarnings("serial")
+public class TradeBotWebSocket extends ApiWebSocket implements Listener {
+
+	/** Cache of trade-bot entry states, keyed by trade-bot entry's "trade private key" (base58) */
+	private static final Map<String, Integer> PREVIOUS_STATES = new HashMap<>();
+
+	private static final Map<Session, String> sessionBlockchain = Collections.synchronizedMap(new HashMap<>());
+
+	@Override
+	public void configure(WebSocketServletFactory factory) {
+		factory.register(TradeBotWebSocket.class);
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			List<TradeBotData> tradeBotEntries = repository.getCrossChainRepository().getAllTradeBotData();
+			if (tradeBotEntries == null)
+				// How do we properly fail here?
+				return;
+
+			PREVIOUS_STATES.putAll(tradeBotEntries.stream().collect(Collectors.toMap(entry -> Base58.encode(entry.getTradePrivateKey()), TradeBotData::getStateValue)));
+		} catch (DataException e) {
+			// No output this time
+		}
+
+		EventBus.INSTANCE.addListener(this::listen);
+	}
+
+	@Override
+	public void listen(Event event) {
+		if (!(event instanceof TradeBot.StateChangeEvent))
+			return;
+
+		TradeBotData tradeBotData = ((TradeBot.StateChangeEvent) event).getTradeBotData();
+		String tradePrivateKey58 = Base58.encode(tradeBotData.getTradePrivateKey());
+
+		synchronized (PREVIOUS_STATES) {
+			Integer previousStateValue = PREVIOUS_STATES.get(tradePrivateKey58);
+			if (previousStateValue != null && previousStateValue == tradeBotData.getStateValue())
+				// Not changed
+				return;
+
+			PREVIOUS_STATES.put(tradePrivateKey58, tradeBotData.getStateValue());
+		}
+
+		List<TradeBotData> tradeBotEntries = Collections.singletonList(tradeBotData);
+
+		for (Session session : getSessions()) {
+			// Only send if this session has this/no preferred blockchain
+			String preferredBlockchain = sessionBlockchain.get(session);
+
+			if (preferredBlockchain == null || preferredBlockchain.equals(tradeBotData.getForeignBlockchain()))
+				sendEntries(session, tradeBotEntries);
+		}
+	}
+
+	@OnWebSocketConnect
+	@Override
+	public void onWebSocketConnect(Session session) {
+		Map<String, List<String>> queryParams = session.getUpgradeRequest().getParameterMap();
+
+		List<String> foreignBlockchains = queryParams.get("foreignBlockchain");
+		final String foreignBlockchain = foreignBlockchains == null ? null : foreignBlockchains.get(0);
+
+		// Make sure blockchain (if any) is valid
+		if (foreignBlockchain != null && SupportedBlockchain.fromString(foreignBlockchain) == null) {
+			session.close(4003, "unknown blockchain: " + foreignBlockchain);
+			return;
+		}
+
+		// save session's preferred blockchain (if any)
+		sessionBlockchain.put(session, foreignBlockchain);
+
+		// Send all known trade-bot entries
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			List<TradeBotData> tradeBotEntries = repository.getCrossChainRepository().getAllTradeBotData();
+
+			// Optional filtering
+			if (foreignBlockchain != null)
+				tradeBotEntries = tradeBotEntries.stream()
+						.filter(tradeBotData -> tradeBotData.getForeignBlockchain().equals(foreignBlockchain))
+						.collect(Collectors.toList());
+
+			if (!sendEntries(session, tradeBotEntries)) {
+				session.close(4002, "websocket issue");
+				return;
+			}
+		} catch (DataException e) {
+			session.close(4001, "repository issue fetching trade-bot entries");
+			return;
+		}
+
+		super.onWebSocketConnect(session);
+	}
+
+	@OnWebSocketClose
+	@Override
+	public void onWebSocketClose(Session session, int statusCode, String reason) {
+		// clean up
+		sessionBlockchain.remove(session);
+
+		super.onWebSocketClose(session, statusCode, reason);
+	}
+
+	@OnWebSocketError
+	public void onWebSocketError(Session session, Throwable throwable) {
+		/* ignored */
+	}
+
+	@OnWebSocketMessage
+	public void onWebSocketMessage(Session session, String message) {
+		/* ignored */
+	}
+
+	private boolean sendEntries(Session session, List<TradeBotData> tradeBotEntries) {
+		try {
+			StringWriter stringWriter = new StringWriter();
+			marshall(stringWriter, tradeBotEntries);
+
+			String output = stringWriter.toString();
+			session.getRemote().sendStringByFuture(output);
+		} catch (IOException e) {
+			// No output this time?
+			return false;
+		}
+
+		return true;
+	}
+
+}

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

@@ -0,0 +1,351 @@
+package org.qortal.api.websocket;
+
+import java.io.IOException;
+import java.io.StringWriter;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.function.Predicate;
+import java.util.function.Supplier;
+import java.util.stream.Collectors;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.eclipse.jetty.websocket.api.Session;
+import org.eclipse.jetty.websocket.api.annotations.OnWebSocketClose;
+import org.eclipse.jetty.websocket.api.annotations.OnWebSocketConnect;
+import org.eclipse.jetty.websocket.api.annotations.OnWebSocketError;
+import org.eclipse.jetty.websocket.api.annotations.OnWebSocketMessage;
+import org.eclipse.jetty.websocket.api.annotations.WebSocket;
+import org.eclipse.jetty.websocket.servlet.WebSocketServletFactory;
+import org.qortal.api.model.CrossChainOfferSummary;
+import org.qortal.controller.Controller;
+import org.qortal.crosschain.SupportedBlockchain;
+import org.qortal.crosschain.ACCT;
+import org.qortal.crosschain.AcctMode;
+import org.qortal.data.at.ATStateData;
+import org.qortal.data.block.BlockData;
+import org.qortal.data.crosschain.CrossChainTradeData;
+import org.qortal.event.Event;
+import org.qortal.event.EventBus;
+import org.qortal.event.Listener;
+import org.qortal.repository.DataException;
+import org.qortal.repository.Repository;
+import org.qortal.repository.RepositoryManager;
+import org.qortal.utils.ByteArray;
+import org.qortal.utils.NTP;
+
+@WebSocket
+@SuppressWarnings("serial")
+public class TradeOffersWebSocket extends ApiWebSocket implements Listener {
+
+	private static final Logger LOGGER = LogManager.getLogger(TradeOffersWebSocket.class);
+
+	private static class CachedOfferInfo {
+		public final Map<String, AcctMode> previousAtModes = new HashMap<>();
+
+		// OFFERING
+		public final Map<String, CrossChainOfferSummary> currentSummaries = new HashMap<>();
+		// REDEEMED/REFUNDED/CANCELLED
+		public final Map<String, CrossChainOfferSummary> historicSummaries = new HashMap<>();
+	}
+	// Manual synchronization
+	private static final Map<String, CachedOfferInfo> cachedInfoByBlockchain = new HashMap<>();
+
+	private static final Predicate<CrossChainOfferSummary> isHistoric = offerSummary
+			-> offerSummary.getMode() == AcctMode.REDEEMED
+			|| offerSummary.getMode() == AcctMode.REFUNDED
+			|| offerSummary.getMode() == AcctMode.CANCELLED;
+
+	private static final Map<Session, String> sessionBlockchain = Collections.synchronizedMap(new HashMap<>());
+
+	@Override
+	public void configure(WebSocketServletFactory factory) {
+		factory.register(TradeOffersWebSocket.class);
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			populateCurrentSummaries(repository);
+
+			populateHistoricSummaries(repository);
+		} catch (DataException e) {
+			// How to fail properly?
+			return;
+		}
+
+		EventBus.INSTANCE.addListener(this::listen);
+	}
+
+	@Override
+	public void listen(Event event) {
+		if (!(event instanceof Controller.NewBlockEvent))
+			return;
+
+		BlockData blockData = ((Controller.NewBlockEvent) event).getBlockData();
+
+		// Process any new info
+
+		try (final Repository repository = RepositoryManager.getRepository()) {
+			// Find any new/changed trade ATs since this block
+			final Boolean isFinished = null;
+			final Integer dataByteOffset = null;
+			final Long expectedValue = null;
+			final Integer minimumFinalHeight = blockData.getHeight();
+
+			for (SupportedBlockchain blockchain : SupportedBlockchain.values()) {
+				Map<ByteArray, Supplier<ACCT>> acctsByCodeHash = SupportedBlockchain.getFilteredAcctMap(blockchain);
+
+				List<CrossChainOfferSummary> crossChainOfferSummaries = new ArrayList<>();
+
+				synchronized (cachedInfoByBlockchain) {
+					CachedOfferInfo cachedInfo = cachedInfoByBlockchain.computeIfAbsent(blockchain.name(), k -> new CachedOfferInfo());
+
+					for (Map.Entry<ByteArray, Supplier<ACCT>> acctInfo : acctsByCodeHash.entrySet()) {
+						byte[] codeHash = acctInfo.getKey().value;
+						ACCT acct = acctInfo.getValue().get();
+
+						List<ATStateData> atStates = repository.getATRepository().getMatchingFinalATStates(codeHash,
+								isFinished, dataByteOffset, expectedValue, minimumFinalHeight,
+								null, null, null);
+
+						crossChainOfferSummaries.addAll(produceSummaries(repository, acct, atStates, blockData.getTimestamp()));
+					}
+
+					// Remove any entries unchanged from last time
+					crossChainOfferSummaries.removeIf(offerSummary -> cachedInfo.previousAtModes.get(offerSummary.getQortalAtAddress()) == offerSummary.getMode());
+
+					// Skip to next blockchain if nothing has changed (for this blockchain)
+					if (crossChainOfferSummaries.isEmpty())
+						continue;
+
+					// Update
+					for (CrossChainOfferSummary offerSummary : crossChainOfferSummaries) {
+						String offerAtAddress = offerSummary.getQortalAtAddress();
+
+						cachedInfo.previousAtModes.put(offerAtAddress, offerSummary.getMode());
+						LOGGER.trace(() -> String.format("Block height: %d, AT: %s, mode: %s", blockData.getHeight(), offerAtAddress, offerSummary.getMode().name()));
+
+						switch (offerSummary.getMode()) {
+							case OFFERING:
+								cachedInfo.currentSummaries.put(offerAtAddress, offerSummary);
+								cachedInfo.historicSummaries.remove(offerAtAddress);
+								break;
+
+							case REDEEMED:
+							case REFUNDED:
+							case CANCELLED:
+								cachedInfo.currentSummaries.remove(offerAtAddress);
+								cachedInfo.historicSummaries.put(offerAtAddress, offerSummary);
+								break;
+
+							case TRADING:
+								cachedInfo.currentSummaries.remove(offerAtAddress);
+								cachedInfo.historicSummaries.remove(offerAtAddress);
+								break;
+						}
+					}
+
+					// Remove any historic offers that are over 24 hours old
+					final long tooOldTimestamp = NTP.getTime() - 24 * 60 * 60 * 1000L;
+					cachedInfo.historicSummaries.values().removeIf(historicSummary -> historicSummary.getTimestamp() < tooOldTimestamp);
+				}
+
+				// Notify sessions
+				for (Session session : getSessions()) {
+					// Only send if this session has this/no preferred blockchain
+					String preferredBlockchain = sessionBlockchain.get(session);
+
+					if (preferredBlockchain == null || preferredBlockchain.equals(blockchain.name()))
+						sendOfferSummaries(session, crossChainOfferSummaries);
+				}
+
+			}
+		} catch (DataException e) {
+			// No output this time
+		}
+	}
+
+	@OnWebSocketConnect
+	@Override
+	public void onWebSocketConnect(Session session) {
+		Map<String, List<String>> queryParams = session.getUpgradeRequest().getParameterMap();
+		final boolean includeHistoric = queryParams.get("includeHistoric") != null;
+
+		List<String> foreignBlockchains = queryParams.get("foreignBlockchain");
+		final String foreignBlockchain = foreignBlockchains == null ? null : foreignBlockchains.get(0);
+
+		// Make sure blockchain (if any) is valid
+		if (foreignBlockchain != null && SupportedBlockchain.fromString(foreignBlockchain) == null) {
+			session.close(4003, "unknown blockchain: " + foreignBlockchain);
+			return;
+		}
+
+		// Save session's preferred blockchain, if given
+		if (foreignBlockchain != null)
+			sessionBlockchain.put(session, foreignBlockchain);
+
+		List<CrossChainOfferSummary> crossChainOfferSummaries = new ArrayList<>();
+
+		synchronized (cachedInfoByBlockchain) {
+			Collection<CachedOfferInfo> cachedInfos;
+
+			if (foreignBlockchain == null)
+				// No preferred blockchain, so iterate through all of them
+				cachedInfos = cachedInfoByBlockchain.values();
+			else
+				cachedInfos = Collections.singleton(cachedInfoByBlockchain.computeIfAbsent(foreignBlockchain, k -> new CachedOfferInfo()));
+
+			for (CachedOfferInfo cachedInfo : cachedInfos) {
+				crossChainOfferSummaries.addAll(cachedInfo.currentSummaries.values());
+
+				if (includeHistoric)
+					crossChainOfferSummaries.addAll(cachedInfo.historicSummaries.values());
+			}
+		}
+
+		if (!sendOfferSummaries(session, crossChainOfferSummaries)) {
+			session.close(4002, "websocket issue");
+			return;
+		}
+
+		super.onWebSocketConnect(session);
+	}
+
+	@OnWebSocketClose
+	@Override
+	public void onWebSocketClose(Session session, int statusCode, String reason) {
+		// clean up
+		sessionBlockchain.remove(session);
+
+		super.onWebSocketClose(session, statusCode, reason);
+	}
+
+	@OnWebSocketError
+	public void onWebSocketError(Session session, Throwable throwable) {
+		/* ignored */
+	}
+
+	@OnWebSocketMessage
+	public void onWebSocketMessage(Session session, String message) {
+		/* ignored */
+	}
+
+	private boolean sendOfferSummaries(Session session, List<CrossChainOfferSummary> crossChainOfferSummaries) {
+		try {
+			StringWriter stringWriter = new StringWriter();
+			marshall(stringWriter, crossChainOfferSummaries);
+
+			String output = stringWriter.toString();
+			session.getRemote().sendStringByFuture(output);
+		} catch (IOException e) {
+			// No output this time?
+			return false;
+		}
+
+		return true;
+	}
+
+	private static void populateCurrentSummaries(Repository repository) throws DataException {
+		// We want ALL OFFERING trades
+		Boolean isFinished = Boolean.FALSE;
+		Long expectedValue = (long) AcctMode.OFFERING.value;
+		Integer minimumFinalHeight = null;
+
+		for (SupportedBlockchain blockchain : SupportedBlockchain.values()) {
+			Map<ByteArray, Supplier<ACCT>> acctsByCodeHash = SupportedBlockchain.getFilteredAcctMap(blockchain);
+
+			CachedOfferInfo cachedInfo = cachedInfoByBlockchain.computeIfAbsent(blockchain.name(), k -> new CachedOfferInfo());
+
+			for (Map.Entry<ByteArray, Supplier<ACCT>> acctInfo : acctsByCodeHash.entrySet()) {
+				byte[] codeHash = acctInfo.getKey().value;
+				ACCT acct = acctInfo.getValue().get();
+
+				Integer dataByteOffset = acct.getModeByteOffset();
+				List<ATStateData> initialAtStates = repository.getATRepository().getMatchingFinalATStates(codeHash,
+					isFinished, dataByteOffset, expectedValue, minimumFinalHeight,
+					null, null, null);
+
+				if (initialAtStates == null)
+					throw new DataException("Couldn't fetch current trades from repository");
+
+				// Save initial AT modes
+				cachedInfo.previousAtModes.putAll(initialAtStates.stream().collect(Collectors.toMap(ATStateData::getATAddress, atState -> AcctMode.OFFERING)));
+
+				// Convert to offer summaries
+				cachedInfo.currentSummaries.putAll(produceSummaries(repository, acct, initialAtStates, null).stream()
+										.collect(Collectors.toMap(CrossChainOfferSummary::getQortalAtAddress, offerSummary -> offerSummary)));
+			}
+		}
+	}
+
+	private static void populateHistoricSummaries(Repository repository) throws DataException {
+		// We want REDEEMED/REFUNDED/CANCELLED trades over the last 24 hours
+		long timestamp = System.currentTimeMillis() - 24 * 60 * 60 * 1000L;
+		int minimumFinalHeight = repository.getBlockRepository().getHeightFromTimestamp(timestamp);
+
+		if (minimumFinalHeight == 0)
+			throw new DataException("Couldn't fetch block timestamp from repository");
+
+		Boolean isFinished = Boolean.TRUE;
+		Integer dataByteOffset = null;
+		Long expectedValue = null;
+		++minimumFinalHeight; // because height is just *before* timestamp
+
+		for (SupportedBlockchain blockchain : SupportedBlockchain.values()) {
+			Map<ByteArray, Supplier<ACCT>> acctsByCodeHash = SupportedBlockchain.getFilteredAcctMap(blockchain);
+
+			CachedOfferInfo cachedInfo = cachedInfoByBlockchain.computeIfAbsent(blockchain.name(), k -> new CachedOfferInfo());
+
+			for (Map.Entry<ByteArray, Supplier<ACCT>> acctInfo : acctsByCodeHash.entrySet()) {
+				byte[] codeHash = acctInfo.getKey().value;
+				ACCT acct = acctInfo.getValue().get();
+
+				List<ATStateData> historicAtStates = repository.getATRepository().getMatchingFinalATStates(codeHash,
+					isFinished, dataByteOffset, expectedValue, minimumFinalHeight,
+					null, null, null);
+
+				if (historicAtStates == null)
+					throw new DataException("Couldn't fetch historic trades from repository");
+
+				for (ATStateData historicAtState : historicAtStates) {
+					CrossChainOfferSummary historicOfferSummary = produceSummary(repository, acct, historicAtState, null);
+
+					if (!isHistoric.test(historicOfferSummary))
+						continue;
+
+					// Add summary to initial burst
+					cachedInfo.historicSummaries.put(historicOfferSummary.getQortalAtAddress(), historicOfferSummary);
+
+					// Save initial AT mode
+					cachedInfo.previousAtModes.put(historicOfferSummary.getQortalAtAddress(), historicOfferSummary.getMode());
+				}
+			}
+		}
+	}
+
+	private static CrossChainOfferSummary produceSummary(Repository repository, ACCT acct, ATStateData atState, Long timestamp) throws DataException {
+		CrossChainTradeData crossChainTradeData = acct.populateTradeData(repository, atState);
+
+		long atStateTimestamp;
+
+		if (crossChainTradeData.mode == AcctMode.OFFERING)
+			// We want when trade was created, not when it was last updated
+			atStateTimestamp = crossChainTradeData.creationTimestamp;
+		else
+			atStateTimestamp = timestamp != null ? timestamp : repository.getBlockRepository().getTimestampFromHeight(atState.getHeight());
+
+		return new CrossChainOfferSummary(crossChainTradeData, atStateTimestamp);
+	}
+
+	private static List<CrossChainOfferSummary> produceSummaries(Repository repository, ACCT acct, List<ATStateData> atStates, Long timestamp) throws DataException {
+		List<CrossChainOfferSummary> offerSummaries = new ArrayList<>();
+
+		for (ATStateData atState : atStates)
+			offerSummaries.add(produceSummary(repository, acct, atState, timestamp));
+
+		return offerSummaries;
+	}
+
+}

src/main/java/org/qortal/asset/Asset.java

@@ -1,11 +1,13 @@
 package org.qortal.asset;
 
+import org.qortal.crypto.Crypto;
 import org.qortal.data.asset.AssetData;
 import org.qortal.data.transaction.IssueAssetTransactionData;
 import org.qortal.data.transaction.TransactionData;
 import org.qortal.data.transaction.UpdateAssetTransactionData;
 import org.qortal.repository.DataException;
 import org.qortal.repository.Repository;
+import org.qortal.utils.Amounts;
 
 public class Asset {
 
@@ -21,12 +23,12 @@ public class Asset {
 
 	// Other useful constants
 
-	public static final int MAX_NAME_SIZE = 400;
+	public static final int MIN_NAME_SIZE = 3;
+	public static final int MAX_NAME_SIZE = 40;
 	public static final int MAX_DESCRIPTION_SIZE = 4000;
 	public static final int MAX_DATA_SIZE = 400000;
 
-	public static final long MAX_DIVISIBLE_QUANTITY = 10_000_000_000L; // but also to 8 decimal places
-	public static final long MAX_INDIVISIBLE_QUANTITY = 1_000_000_000_000_000_000L;
+	public static final long MAX_QUANTITY = 10_000_000_000L * Amounts.MULTIPLIER; // but also to 8 decimal places
 
 	// Properties
 	private Repository repository;
@@ -42,12 +44,14 @@ public class Asset {
 	public Asset(Repository repository, IssueAssetTransactionData issueAssetTransactionData) {
 		this.repository = repository;
 
+		String ownerAddress = Crypto.toAddress(issueAssetTransactionData.getCreatorPublicKey());
+
 		// NOTE: transaction's reference is used to look up newly assigned assetID on creation!
-		this.assetData = new AssetData(issueAssetTransactionData.getOwner(), issueAssetTransactionData.getAssetName(),
+		this.assetData = new AssetData(ownerAddress, issueAssetTransactionData.getAssetName(),
 				issueAssetTransactionData.getDescription(), issueAssetTransactionData.getQuantity(),
-				issueAssetTransactionData.getIsDivisible(), issueAssetTransactionData.getData(),
-				issueAssetTransactionData.getIsUnspendable(),
-				issueAssetTransactionData.getTxGroupId(), issueAssetTransactionData.getSignature());
+				issueAssetTransactionData.isDivisible(), issueAssetTransactionData.getData(),
+				issueAssetTransactionData.isUnspendable(), issueAssetTransactionData.getTxGroupId(),
+				issueAssetTransactionData.getSignature(), issueAssetTransactionData.getReducedAssetName());
 	}
 
 	public Asset(Repository repository, long assetId) throws DataException {
@@ -118,10 +122,11 @@ public class Asset {
 				throw new IllegalStateException("Missing referenced transaction when orphaning UPDATE_ASSET");
 
 			switch (previousTransactionData.getType()) {
-				case ISSUE_ASSET:
+				case ISSUE_ASSET: {
 					IssueAssetTransactionData previousIssueAssetTransactionData = (IssueAssetTransactionData) previousTransactionData;
 
-					this.assetData.setOwner(previousIssueAssetTransactionData.getOwner());
+					String ownerAddress = Crypto.toAddress(previousIssueAssetTransactionData.getCreatorPublicKey());
+					this.assetData.setOwner(ownerAddress);
 
 					if (needDescription) {
 						this.assetData.setDescription(previousIssueAssetTransactionData.getDescription());
@@ -133,8 +138,9 @@ public class Asset {
 						needData = false;
 					}
 					break;
+				}
 
-				case UPDATE_ASSET:
+				case UPDATE_ASSET: {
 					UpdateAssetTransactionData previousUpdateAssetTransactionData = (UpdateAssetTransactionData) previousTransactionData;
 
 					this.assetData.setOwner(previousUpdateAssetTransactionData.getNewOwner());
@@ -152,7 +158,9 @@ public class Asset {
 					// Get signature for previous transaction in chain, just in case we need it
 					if (needDescription || needData)
 						previousTransactionSignature = previousUpdateAssetTransactionData.getOrphanReference();
+
 					break;
+				}
 
 				default:
 					throw new IllegalStateException("Invalid referenced transaction when orphaning UPDATE_ASSET");

src/main/java/org/qortal/asset/Order.java

@@ -1,8 +1,8 @@
 package org.qortal.asset;
 
-import java.math.BigDecimal;
+import static org.qortal.utils.Amounts.prettyAmount;
+
 import java.math.BigInteger;
-import java.math.RoundingMode;
 import java.util.Arrays;
 import java.util.List;
 
@@ -11,13 +11,12 @@ import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.qortal.account.Account;
 import org.qortal.account.PublicKeyAccount;
-import org.qortal.block.BlockChain;
 import org.qortal.data.asset.AssetData;
 import org.qortal.data.asset.OrderData;
 import org.qortal.data.asset.TradeData;
-import org.qortal.repository.AssetRepository;
 import org.qortal.repository.DataException;
 import org.qortal.repository.Repository;
+import org.qortal.utils.Amounts;
 import org.qortal.utils.Base58;
 
 public class Order {
@@ -29,9 +28,11 @@ public class Order {
 	private OrderData orderData;
 
 	// Used quite a bit
-	private final boolean isOurOrderNewPricing;
 	private final long haveAssetId;
 	private final long wantAssetId;
+	private final boolean isAmountInWantAsset;
+	private final BigInteger orderAmount;
+	private final BigInteger orderPrice;
 
 	/** Cache of price-pair units e.g. QORT/GOLD, but use getPricePair() instead! */
 	private String cachedPricePair;
@@ -47,9 +48,12 @@ public class Order {
 		this.repository = repository;
 		this.orderData = orderData;
 
-		this.isOurOrderNewPricing = this.orderData.getTimestamp() >= BlockChain.getInstance().getNewAssetPricingTimestamp();
 		this.haveAssetId = this.orderData.getHaveAssetId();
 		this.wantAssetId = this.orderData.getWantAssetId();
+		this.isAmountInWantAsset = haveAssetId < wantAssetId;
+
+		this.orderAmount = BigInteger.valueOf(this.orderData.getAmount());
+		this.orderPrice = BigInteger.valueOf(this.orderData.getPrice());
 	}
 
 	// Getters/Setters
@@ -60,16 +64,16 @@ public class Order {
 
 	// More information
 
-	public static BigDecimal getAmountLeft(OrderData orderData) {
-		return orderData.getAmount().subtract(orderData.getFulfilled());
+	public static long getAmountLeft(OrderData orderData) {
+		return orderData.getAmount() - orderData.getFulfilled();
 	}
 
-	public BigDecimal getAmountLeft() {
+	public long getAmountLeft() {
 		return Order.getAmountLeft(this.orderData);
 	}
 
 	public static boolean isFulfilled(OrderData orderData) {
-		return orderData.getFulfilled().compareTo(orderData.getAmount()) == 0;
+		return orderData.getFulfilled() == orderData.getAmount();
 	}
 
 	public boolean isFulfilled() {
@@ -86,13 +90,10 @@ public class Order {
 	 * <p>
 	 * @return granularity of matched-amount
 	 */
-	public static BigDecimal calculateAmountGranularity(boolean isAmountAssetDivisible, boolean isReturnAssetDivisible, BigDecimal price) {
-		// Multiplier to scale BigDecimal fractional amounts into integer domain
-		BigInteger multiplier = BigInteger.valueOf(1_0000_0000L);
-
+	public static long calculateAmountGranularity(boolean isAmountAssetDivisible, boolean isReturnAssetDivisible, long price) {
 		// Calculate the minimum increment for matched-amount using greatest-common-divisor
-		BigInteger returnAmount = multiplier; // 1 unit (* multiplier)
-		BigInteger matchedAmount = price.movePointRight(8).toBigInteger();
+		BigInteger returnAmount = Amounts.MULTIPLIER_BI; // 1 unit * multiplier
+		BigInteger matchedAmount = BigInteger.valueOf(price);
 
 		BigInteger gcd = returnAmount.gcd(matchedAmount);
 		returnAmount = returnAmount.divide(gcd);
@@ -100,20 +101,20 @@ public class Order {
 
 		// Calculate GCD in combination with divisibility
 		if (isAmountAssetDivisible)
-			returnAmount = returnAmount.multiply(multiplier);
+			returnAmount = returnAmount.multiply(Amounts.MULTIPLIER_BI);
 
 		if (isReturnAssetDivisible)
-			matchedAmount = matchedAmount.multiply(multiplier);
+			matchedAmount = matchedAmount.multiply(Amounts.MULTIPLIER_BI);
 
 		gcd = returnAmount.gcd(matchedAmount);
 
 		// Calculate the granularity at which we have to buy
-		BigDecimal granularity = new BigDecimal(returnAmount.divide(gcd));
+		BigInteger granularity = returnAmount.multiply(Amounts.MULTIPLIER_BI).divide(gcd);
 		if (isAmountAssetDivisible)
-			granularity = granularity.movePointLeft(8);
+			granularity = granularity.divide(Amounts.MULTIPLIER_BI);
 
 		// Return
-		return granularity;
+		return granularity.longValue();
 	}
 
 	/**
@@ -130,7 +131,7 @@ public class Order {
 
 	/** Calculate price pair. (e.g. QORT/GOLD)
 	 * <p>
-	 * Under 'new' pricing scheme, lowest-assetID asset is first,
+	 * Lowest-assetID asset is first,
 	 * so if QORT has assetID 0 and GOLD has assetID 10, then
 	 * the pricing pair is QORT/GOLD.
 	 * <p>
@@ -141,32 +142,32 @@ public class Order {
 		AssetData haveAssetData = getHaveAsset();
 		AssetData wantAssetData = getWantAsset();
 
-		if (isOurOrderNewPricing && haveAssetId > wantAssetId)
+		if (haveAssetId > wantAssetId)
 			cachedPricePair = wantAssetData.getName() + "/" + haveAssetData.getName();
 		else
 			cachedPricePair = haveAssetData.getName() + "/" + wantAssetData.getName();
 	}
 
 	/** Returns amount of have-asset to remove from order's creator's balance on placing this order. */
-	private BigDecimal calcHaveAssetCommittment() {
-		BigDecimal committedCost = this.orderData.getAmount();
+	private long calcHaveAssetCommittment() {
+		// Simple case: amount is in have asset
+		if (!this.isAmountInWantAsset)
+			return this.orderData.getAmount();
 
-		// If 'new' pricing and "amount" is in want-asset then we need to convert
-		if (isOurOrderNewPricing && haveAssetId < wantAssetId)
-			committedCost = committedCost.multiply(this.orderData.getPrice()).setScale(8, RoundingMode.HALF_UP);
+		return Amounts.roundUpScaledMultiply(this.orderAmount, this.orderPrice);
+	}
 
-		return committedCost;
+	private long calcHaveAssetRefund(long amount) {
+		// Simple case: amount is in have asset
+		if (!this.isAmountInWantAsset)
+			return amount;
+
+		return Amounts.roundUpScaledMultiply(BigInteger.valueOf(amount), this.orderPrice);
 	}
 
 	/** Returns amount of remaining have-asset to refund to order's creator's balance on cancelling this order. */
-	private BigDecimal calcHaveAssetRefund() {
-		BigDecimal refund = getAmountLeft();
-
-		// If 'new' pricing and "amount" is in want-asset then we need to convert
-		if (isOurOrderNewPricing && haveAssetId < wantAssetId)
-			refund = refund.multiply(this.orderData.getPrice()).setScale(8, RoundingMode.HALF_UP);
-
-		return refund;
+	private long calcHaveAssetRefund() {
+		return calcHaveAssetRefund(getAmountLeft());
 	}
 
 	// Navigation
@@ -192,27 +193,19 @@ public class Order {
 	/**
 	 * Returns AssetData for asset in effect for "amount" field.
 	 * <p>
-	 * For 'old' pricing, this is the have-asset.<br>
-	 * For 'new' pricing, this is the asset with highest assetID.
+	 * This is the asset with highest assetID.
 	 */
 	public AssetData getAmountAsset() throws DataException {
-		if (isOurOrderNewPricing && wantAssetId > haveAssetId)
-			return getWantAsset();
-		else
-			return getHaveAsset();
+		return (wantAssetId > haveAssetId) ? getWantAsset() : getHaveAsset();
 	}
 
 	/**
 	 * Returns AssetData for other (return) asset traded.
 	 * <p>
-	 * For 'old' pricing, this is the want-asset.<br>
-	 * For 'new' pricing, this is the asset with lowest assetID.
+	 * This is the asset with lowest assetID.
 	 */
 	public AssetData getReturnAsset() throws DataException {
-		if (isOurOrderNewPricing && haveAssetId < wantAssetId)
-			return getHaveAsset();
-		else
-			return getWantAsset();
+		return (haveAssetId < wantAssetId) ? getHaveAsset() : getWantAsset();
 	}
 
 	// Processing
@@ -227,8 +220,6 @@ public class Order {
 
 		// NOTE: the following values are specific to passed orderData, not the same as class instance values!
 
-		final boolean isOrderNewAssetPricing = orderData.getTimestamp() >= BlockChain.getInstance().getNewAssetPricingTimestamp();
-
 		// Cached for readability
 		final long _haveAssetId = orderData.getHaveAssetId();
 		final long _wantAssetId = orderData.getWantAssetId();
@@ -236,43 +227,36 @@ public class Order {
 		final AssetData haveAssetData = this.repository.getAssetRepository().fromAssetId(_haveAssetId);
 		final AssetData wantAssetData = this.repository.getAssetRepository().fromAssetId(_wantAssetId);
 
-		final long amountAssetId = (isOurOrderNewPricing && _wantAssetId > _haveAssetId) ? _wantAssetId : _haveAssetId;
-		final long returnAssetId = (isOurOrderNewPricing && _haveAssetId < _wantAssetId) ? _haveAssetId : _wantAssetId;
+		final long amountAssetId = (_wantAssetId > _haveAssetId) ? _wantAssetId : _haveAssetId;
+		final long returnAssetId = (_haveAssetId < _wantAssetId) ? _haveAssetId : _wantAssetId;
 
 		final AssetData amountAssetData = this.repository.getAssetRepository().fromAssetId(amountAssetId);
 		final AssetData returnAssetData = this.repository.getAssetRepository().fromAssetId(returnAssetId);
 
-		LOGGER.debug(String.format("%s %s", orderPrefix, Base58.encode(orderData.getOrderId())));
+		LOGGER.debug(() -> String.format("%s %s", orderPrefix, Base58.encode(orderData.getOrderId())));
 
-		LOGGER.trace(String.format("%s have %s, want %s. '%s' pricing scheme.", weThey, haveAssetData.getName(), wantAssetData.getName(), isOrderNewAssetPricing ? "new" : "old"));
+		LOGGER.trace(() -> String.format("%s have %s, want %s.", weThey, haveAssetData.getName(), wantAssetData.getName()));
 
-		LOGGER.trace(String.format("%s amount: %s (ordered) - %s (fulfilled) = %s %s left", ourTheir,
-				orderData.getAmount().stripTrailingZeros().toPlainString(),
-				orderData.getFulfilled().stripTrailingZeros().toPlainString(),
-				Order.getAmountLeft(orderData).stripTrailingZeros().toPlainString(),
+		LOGGER.trace(() -> String.format("%s amount: %s (ordered) - %s (fulfilled) = %s %s left", ourTheir,
+				prettyAmount(orderData.getAmount()),
+				prettyAmount(orderData.getFulfilled()),
+				prettyAmount(Order.getAmountLeft(orderData)),
 				amountAssetData.getName()));
 
-		BigDecimal maxReturnAmount = Order.getAmountLeft(orderData).multiply(orderData.getPrice()).setScale(8, RoundingMode.HALF_UP);
+		long maxReturnAmount = Amounts.roundUpScaledMultiply(Order.getAmountLeft(orderData), orderData.getPrice());
+		String pricePair = getPricePair();
 
-		LOGGER.trace(String.format("%s price: %s %s (%s %s tradable)", ourTheir,
-				orderData.getPrice().toPlainString(), getPricePair(),
-				maxReturnAmount.stripTrailingZeros().toPlainString(), returnAssetData.getName()));
+		LOGGER.trace(() -> String.format("%s price: %s %s (%s %s tradable)", ourTheir,
+				prettyAmount(orderData.getPrice()),
+				pricePair,
+				prettyAmount(maxReturnAmount),
+				returnAssetData.getName()));
 	}
 
 	public void process() throws DataException {
-		AssetRepository assetRepository = this.repository.getAssetRepository();
-
-		AssetData haveAssetData = getHaveAsset();
-		AssetData wantAssetData = getWantAsset();
-
-		/** The asset while working out amount that matches. */
-		AssetData matchingAssetData = isOurOrderNewPricing ? getAmountAsset() : wantAssetData;
-		/** The return asset traded if trade completes. */
-		AssetData returnAssetData = isOurOrderNewPricing ? getReturnAsset() : haveAssetData;
-
 		// Subtract have-asset from creator
 		Account creator = new PublicKeyAccount(this.repository, this.orderData.getCreatorPublicKey());
-		creator.setConfirmedBalance(haveAssetId, creator.getConfirmedBalance(haveAssetId).subtract(this.calcHaveAssetCommittment()));
+		creator.modifyAssetBalance(haveAssetId, - this.calcHaveAssetCommittment());
 
 		// Save this order into repository so it's available for matching, possibly by itself
 		this.repository.getAssetRepository().save(this.orderData);
@@ -281,36 +265,28 @@ public class Order {
 
 		// Fetch corresponding open orders that might potentially match, hence reversed want/have assetIDs.
 		// Returned orders are sorted with lowest "price" first.
-		List<OrderData> orders = assetRepository.getOpenOrdersForTrading(wantAssetId, haveAssetId, isOurOrderNewPricing ? this.orderData.getPrice() : null);
-		LOGGER.trace("Open orders fetched from repository: " + orders.size());
+		List<OrderData> orders = this.repository.getAssetRepository().getOpenOrdersForTrading(wantAssetId, haveAssetId, this.orderData.getPrice());
+		LOGGER.trace(() -> String.format("Open orders fetched from repository: %d", orders.size()));
 
 		if (orders.isEmpty())
 			return;
 
+		matchOrders(orders);
+	}
+
+	private void matchOrders(List<OrderData> orders) throws DataException {
+		AssetData haveAssetData = getHaveAsset();
+		AssetData wantAssetData = getWantAsset();
+
+		/** The asset while working out amount that matches. */
+		AssetData matchingAssetData = getAmountAsset();
+		/** The return asset traded if trade completes. */
+		AssetData returnAssetData = getReturnAsset();
+
 		// Attempt to match orders
 
 		/*
-		 * Potential matching order example ("old"):
-		 * 
-		 * Our order:
-		 * haveAssetId=[GOLD], wantAssetId=0 (QORT), amount=40 (GOLD), price=486 (QORT/GOLD)
-		 * This translates to "we have 40 GOLD and want QORT at a price of 486 QORT per GOLD"
-		 * If our order matched, we'd end up with 40 * 486 = 19,440 QORT.
-		 * 
-		 * Their order:
-		 * haveAssetId=0 (QORT), wantAssetId=[GOLD], amount=20,000 (QORT), price=0.00205761 (GOLD/QORT)
-		 * This translates to "they have 20,000 QORT and want GOLD at a price of 0.00205761 GOLD per QORT"
-		 * 
-		 * Their price, converted into 'our' units of QORT/GOLD, is: 1 / 0.00205761 = 486.00074844 QORT/GOLD.
-		 * This is better than our requested 486 QORT/GOLD so this order matches.
-		 * 
-		 * Using their price, we end up with 40 * 486.00074844 = 19440.02993760 QORT. They end up with 40 GOLD.
-		 * 
-		 * If their order had 19,440 QORT left, only 19,440 * 0.00205761 = 39.99993840 GOLD would be traded.
-		 */
-
-		/*
-		 * Potential matching order example ("new"):
+		 * Potential matching order example:
 		 * 
 		 * Our order:
 		 * haveAssetId=[GOLD], wantAssetId=0 (QORT), amount=40 (GOLD), price=486 (QORT/GOLD)
@@ -328,129 +304,107 @@ public class Order {
 		 * If their order only had 36 GOLD left, only 36 * 486.00074844 = 17496.02694384 QORT would be traded.
 		 */
 
-		BigDecimal ourPrice = this.orderData.getPrice();
+		long ourPrice = this.orderData.getPrice();
+		String pricePair = getPricePair();
 
 		for (OrderData theirOrderData : orders) {
 			logOrder("Considering order", false, theirOrderData);
 
-			// Not used:
-			// boolean isTheirOrderNewAssetPricing = theirOrderData.getTimestamp() >= BlockChain.getInstance().getNewAssetPricingTimestamp();
-
 			// Determine their order price
-			BigDecimal theirPrice;
-
-			if (isOurOrderNewPricing) {
-				// Pricing units are the same way round for both orders, so no conversion needed.
-				// Orders under 'old' pricing have been converted during repository update.
-				theirPrice = theirOrderData.getPrice();
-				LOGGER.trace(String.format("Their price: %s %s", theirPrice.toPlainString(), getPricePair()));
-			} else {
-				// If our order is 'old' pricing then all other existing orders must be 'old' pricing too
-				// Their order pricing will be inverted, so convert
-				theirPrice = BigDecimal.ONE.setScale(8).divide(theirOrderData.getPrice(), RoundingMode.DOWN);
-				LOGGER.trace(String.format("Their price: %s %s per %s", theirPrice.toPlainString(), wantAssetData.getName(), haveAssetData.getName()));
-			}
+			long theirPrice = theirOrderData.getPrice();
+			LOGGER.trace(() -> String.format("Their price: %s %s", prettyAmount(theirPrice), pricePair));
 
 			// If their price is worse than what we're willing to accept then we're done as prices only get worse as we iterate through list of orders
-			if (isOurOrderNewPricing) {
-				if (haveAssetId < wantAssetId && theirPrice.compareTo(ourPrice) > 0)
-					break;
-				if (haveAssetId > wantAssetId && theirPrice.compareTo(ourPrice) < 0)
-					break;
-			} else {
-				// 'old' pricing scheme
-				if (theirPrice.compareTo(ourPrice) < 0)
-					break;
-			}
+			if ((haveAssetId < wantAssetId && theirPrice > ourPrice) || (haveAssetId > wantAssetId && theirPrice < ourPrice))
+				break;
 
-			// Calculate how much we could buy at their price.
-			BigDecimal ourMaxAmount;
-			if (isOurOrderNewPricing)
-				// In 'new' pricing scheme, "amount" is expressed in terms of asset with highest assetID
-				ourMaxAmount = this.getAmountLeft();
-			else
-				// In 'old' pricing scheme, "amount" is expressed in terms of our want-asset.
-				ourMaxAmount = this.getAmountLeft().multiply(theirPrice).setScale(8, RoundingMode.DOWN);
-			LOGGER.trace("ourMaxAmount (max we could trade at their price): " + ourMaxAmount.stripTrailingZeros().toPlainString() + " " + matchingAssetData.getName());
+			// Calculate how much we could buy at their price, "amount" is expressed in terms of asset with highest assetID.
+			long ourMaxAmount = this.getAmountLeft();
+			LOGGER.trace(() -> String.format("ourMaxAmount (max we could trade at their price): %s %s", prettyAmount(ourMaxAmount), matchingAssetData.getName()));
 
 			// How much is remaining available in their order.
-			BigDecimal theirAmountLeft = Order.getAmountLeft(theirOrderData);
-			LOGGER.trace("theirAmountLeft (max amount remaining in their order): " + theirAmountLeft.stripTrailingZeros().toPlainString() + " " + matchingAssetData.getName());
+			long theirAmountLeft = Order.getAmountLeft(theirOrderData);
+			LOGGER.trace(() -> String.format("theirAmountLeft (max amount remaining in their order): %s %s", prettyAmount(theirAmountLeft), matchingAssetData.getName()));
 
 			// So matchable want-asset amount is the minimum of above two values
-			BigDecimal matchedAmount = ourMaxAmount.min(theirAmountLeft);
-			LOGGER.trace("matchedAmount: " + matchedAmount.stripTrailingZeros().toPlainString() + " " + matchingAssetData.getName());
+			long interimMatchedAmount = Math.min(ourMaxAmount, theirAmountLeft);
+			LOGGER.trace(() -> String.format("matchedAmount: %s %s", prettyAmount(interimMatchedAmount), matchingAssetData.getName()));
 
 			// If we can't buy anything then try another order
-			if (matchedAmount.compareTo(BigDecimal.ZERO) <= 0)
+			if (interimMatchedAmount <= 0)
 				continue;
 
 			// Calculate amount granularity, based on price and both assets' divisibility, so that return-amount traded is a valid value (integer or to 8 d.p.)
-			BigDecimal granularity = calculateAmountGranularity(matchingAssetData.getIsDivisible(), returnAssetData.getIsDivisible(), theirOrderData.getPrice());
-			LOGGER.trace("granularity (amount granularity): " + granularity.stripTrailingZeros().toPlainString() + " " + matchingAssetData.getName());
+			long granularity = calculateAmountGranularity(matchingAssetData.isDivisible(), returnAssetData.isDivisible(), theirOrderData.getPrice());
+			LOGGER.trace(() -> String.format("granularity (amount granularity): %s %s", prettyAmount(granularity), matchingAssetData.getName()));
 
 			// Reduce matched amount (if need be) to fit granularity
-			matchedAmount = matchedAmount.subtract(matchedAmount.remainder(granularity));
-			LOGGER.trace("matchedAmount adjusted for granularity: " + matchedAmount.stripTrailingZeros().toPlainString() + " " + matchingAssetData.getName());
+			long matchedAmount = interimMatchedAmount - interimMatchedAmount % granularity;
+			LOGGER.trace(() -> String.format("matchedAmount adjusted for granularity: %s %s", prettyAmount(matchedAmount), matchingAssetData.getName()));
 
 			// If we can't buy anything then try another order
-			if (matchedAmount.compareTo(BigDecimal.ZERO) <= 0)
+			if (matchedAmount <= 0)
 				continue;
 
 			// Safety check
-			if (!matchingAssetData.getIsDivisible() && matchedAmount.stripTrailingZeros().scale() > 0) {
-				Account participant = new PublicKeyAccount(this.repository, theirOrderData.getCreatorPublicKey());
-
-				String message = String.format("Refusing to trade fractional %s [indivisible assetID %d] for %s",
-						matchedAmount.toPlainString(), matchingAssetData.getAssetId(), participant.getAddress());
-				LOGGER.error(message);
-				throw new DataException(message);
-			}
+			checkDivisibility(matchingAssetData, matchedAmount, theirOrderData);
 
 			// Trade can go ahead!
 
 			// Calculate the total cost to us, in return-asset, based on their price
-			BigDecimal returnAmountTraded = matchedAmount.multiply(theirOrderData.getPrice()).setScale(8, RoundingMode.DOWN);
-			LOGGER.trace("returnAmountTraded: " + returnAmountTraded.stripTrailingZeros().toPlainString() + " " + returnAssetData.getName());
+			long returnAmountTraded = Amounts.roundDownScaledMultiply(matchedAmount, theirOrderData.getPrice());
+			LOGGER.trace(() -> String.format("returnAmountTraded: %s %s", prettyAmount(returnAmountTraded), returnAssetData.getName()));
 
 			// Safety check
-			if (!returnAssetData.getIsDivisible() && returnAmountTraded.stripTrailingZeros().scale() > 0) {
-				String message = String.format("Refusing to trade fractional %s [indivisible assetID %d] for %s",
-						returnAmountTraded.toPlainString(), returnAssetData.getAssetId(), creator.getAddress());
-				LOGGER.error(message);
-				throw new DataException(message);
-			}
+			checkDivisibility(returnAssetData, returnAmountTraded, this.orderData);
 
-			BigDecimal tradedWantAmount = (isOurOrderNewPricing && haveAssetId > wantAssetId) ? returnAmountTraded : matchedAmount;
-			BigDecimal tradedHaveAmount = (isOurOrderNewPricing && haveAssetId > wantAssetId) ? matchedAmount : returnAmountTraded;
+			long tradedWantAmount = this.isAmountInWantAsset ? matchedAmount : returnAmountTraded;
+			long tradedHaveAmount = this.isAmountInWantAsset ? returnAmountTraded : matchedAmount;
 
-			// We also need to know how much have-asset to refund based on price improvement ('new' pricing only and only one direction applies)
-			BigDecimal haveAssetRefund = isOurOrderNewPricing && haveAssetId < wantAssetId ? ourPrice.subtract(theirPrice).abs().multiply(matchedAmount).setScale(8, RoundingMode.DOWN) : BigDecimal.ZERO;
+			// We also need to know how much have-asset to refund based on price improvement (only one direction applies)
+			long haveAssetRefund = this.isAmountInWantAsset ? Amounts.roundDownScaledMultiply(matchedAmount, Math.abs(ourPrice - theirPrice)) : 0;
 
-			LOGGER.trace(String.format("We traded %s %s (have-asset) for %s %s (want-asset), saving %s %s (have-asset)",
-					tradedHaveAmount.toPlainString(), haveAssetData.getName(),
-					tradedWantAmount.toPlainString(), wantAssetData.getName(),
-					haveAssetRefund.toPlainString(), haveAssetData.getName()));
+			LOGGER.trace(() -> String.format("We traded %s %s (have-asset) for %s %s (want-asset), saving %s %s (have-asset)",
+					prettyAmount(tradedHaveAmount), haveAssetData.getName(),
+					prettyAmount(tradedWantAmount), wantAssetData.getName(),
+					prettyAmount(haveAssetRefund), haveAssetData.getName()));
 
 			// Construct trade
 			TradeData tradeData = new TradeData(this.orderData.getOrderId(), theirOrderData.getOrderId(),
 					tradedWantAmount, tradedHaveAmount, haveAssetRefund, this.orderData.getTimestamp());
+
 			// Process trade, updating corresponding orders in repository
 			Trade trade = new Trade(this.repository, tradeData);
 			trade.process();
 
 			// Update our order in terms of fulfilment, etc. but do not save into repository as that's handled by Trade above
-			BigDecimal amountFulfilled = isOurOrderNewPricing ? matchedAmount : returnAmountTraded;
-			this.orderData.setFulfilled(this.orderData.getFulfilled().add(amountFulfilled));
-			LOGGER.trace("Updated our order's fulfilled amount to: " + this.orderData.getFulfilled().stripTrailingZeros().toPlainString() + " " + matchingAssetData.getName());
-			LOGGER.trace("Our order's amount remaining: " + this.getAmountLeft().stripTrailingZeros().toPlainString() + " " + matchingAssetData.getName());
+			long amountFulfilled = matchedAmount;
+			this.orderData.setFulfilled(this.orderData.getFulfilled() + amountFulfilled);
+			LOGGER.trace(() -> String.format("Updated our order's fulfilled amount to: %s %s", prettyAmount(this.orderData.getFulfilled()), matchingAssetData.getName()));
+			LOGGER.trace(() -> String.format("Our order's amount remaining: %s %s", prettyAmount(this.getAmountLeft()), matchingAssetData.getName()));
 
 			// Continue on to process other open orders if we still have amount left to match
-			if (this.getAmountLeft().compareTo(BigDecimal.ZERO) <= 0)
+			if (this.getAmountLeft() <= 0)
 				break;
 		}
 	}
 
+	/**
+	 * Check amount has no fractional part if asset is indivisible.
+	 * 
+	 * @throws DataException if divisibility check fails
+	 */
+	private void checkDivisibility(AssetData assetData, long amount, OrderData orderData) throws DataException {
+		if (assetData.isDivisible() || amount % Amounts.MULTIPLIER == 0)
+			// Asset is divisible or amount has no fractional part
+			return;
+
+		String message = String.format("Refusing to trade fractional %s [indivisible assetID %d] for order %s",
+				prettyAmount(amount), assetData.getAssetId(), Base58.encode(orderData.getOrderId()));
+		LOGGER.error(message);
+		throw new DataException(message);
+	}
+
 	public void orphan() throws DataException {
 		// Orphan trades that occurred as a result of this order
 		for (TradeData tradeData : getTrades())
@@ -464,7 +418,7 @@ public class Order {
 
 		// Return asset to creator
 		Account creator = new PublicKeyAccount(this.repository, this.orderData.getCreatorPublicKey());
-		creator.setConfirmedBalance(haveAssetId, creator.getConfirmedBalance(haveAssetId).add(this.calcHaveAssetCommittment()));
+		creator.modifyAssetBalance(haveAssetId, this.calcHaveAssetCommittment());
 	}
 
 	// This is called by CancelOrderTransaction so that an Order can no longer trade
@@ -474,14 +428,14 @@ public class Order {
 
 		// Update creator's balance with unfulfilled amount
 		Account creator = new PublicKeyAccount(this.repository, this.orderData.getCreatorPublicKey());
-		creator.setConfirmedBalance(haveAssetId, creator.getConfirmedBalance(haveAssetId).add(calcHaveAssetRefund()));
+		creator.modifyAssetBalance(haveAssetId, calcHaveAssetRefund());
 	}
 
 	// Opposite of cancel() above for use during orphaning
 	public void reopen() throws DataException {
 		// Update creator's balance with unfulfilled amount
 		Account creator = new PublicKeyAccount(this.repository, this.orderData.getCreatorPublicKey());
-		creator.setConfirmedBalance(haveAssetId, creator.getConfirmedBalance(haveAssetId).subtract(calcHaveAssetRefund()));
+		creator.modifyAssetBalance(haveAssetId, - calcHaveAssetRefund());
 
 		this.orderData.setIsClosed(false);
 		this.repository.getAssetRepository().save(this.orderData);

src/main/java/org/qortal/asset/Trade.java

@@ -1,10 +1,7 @@
 package org.qortal.asset;
 
-import java.math.BigDecimal;
-
 import org.qortal.account.Account;
 import org.qortal.account.PublicKeyAccount;
-import org.qortal.block.BlockChain;
 import org.qortal.data.asset.OrderData;
 import org.qortal.data.asset.TradeData;
 import org.qortal.repository.AssetRepository;
@@ -17,12 +14,11 @@ public class Trade {
 	private Repository repository;
 	private TradeData tradeData;
 
-	private boolean isNewPricing;
 	private AssetRepository assetRepository;
 
 	private OrderData initiatingOrder;
 	private OrderData targetOrder;
-	private BigDecimal newPricingFulfilled;
+	private long fulfilled;
 
 	// Constructors
 
@@ -30,7 +26,6 @@ public class Trade {
 		this.repository = repository;
 		this.tradeData = tradeData;
 
-		this.isNewPricing = this.tradeData.getTimestamp() > BlockChain.getInstance().getNewAssetPricingTimestamp();
 		this.assetRepository = this.repository.getAssetRepository();
 	}
 
@@ -43,9 +38,9 @@ public class Trade {
 		// Note: targetAmount is amount traded FROM target order
 		// Note: initiatorAmount is amount traded FROM initiating order
 
-		// Under 'new' pricing scheme, "amount" and "fulfilled" are the same asset for both orders
+		// "amount" and "fulfilled" are the same asset for both orders
 		// which is the matchedAmount in asset with highest assetID
-		this.newPricingFulfilled = (initiatingOrder.getHaveAssetId() < initiatingOrder.getWantAssetId()) ? this.tradeData.getTargetAmount() : this.tradeData.getInitiatorAmount();
+		this.fulfilled = initiatingOrder.getHaveAssetId() < initiatingOrder.getWantAssetId() ? this.tradeData.getTargetAmount() : this.tradeData.getInitiatorAmount();
 	}
 
 	public void process() throws DataException {
@@ -55,16 +50,16 @@ public class Trade {
 		// Note: targetAmount is amount traded FROM target order
 		// Note: initiatorAmount is amount traded FROM initiating order
 
-		// Update corresponding Orders on both sides of trade
 		commonPrep();
 
-		initiatingOrder.setFulfilled(initiatingOrder.getFulfilled().add(isNewPricing ? newPricingFulfilled : tradeData.getInitiatorAmount()));
+		// Update corresponding Orders on both sides of trade
+		initiatingOrder.setFulfilled(initiatingOrder.getFulfilled() + fulfilled);
 		initiatingOrder.setIsFulfilled(Order.isFulfilled(initiatingOrder));
 		// Set isClosed to true if isFulfilled now true
 		initiatingOrder.setIsClosed(initiatingOrder.getIsFulfilled());
 		assetRepository.save(initiatingOrder);
 
-		targetOrder.setFulfilled(targetOrder.getFulfilled().add(isNewPricing ? newPricingFulfilled : tradeData.getTargetAmount()));
+		targetOrder.setFulfilled(targetOrder.getFulfilled() + fulfilled);
 		targetOrder.setIsFulfilled(Order.isFulfilled(targetOrder));
 		// Set isClosed to true if isFulfilled now true
 		targetOrder.setIsClosed(targetOrder.getIsFulfilled());
@@ -72,33 +67,31 @@ public class Trade {
 
 		// Actually transfer asset balances
 		Account initiatingCreator = new PublicKeyAccount(this.repository, initiatingOrder.getCreatorPublicKey());
-		initiatingCreator.setConfirmedBalance(initiatingOrder.getWantAssetId(), initiatingCreator.getConfirmedBalance(initiatingOrder.getWantAssetId()).add(tradeData.getTargetAmount()));
+		initiatingCreator.modifyAssetBalance(initiatingOrder.getWantAssetId(), tradeData.getTargetAmount());
 
 		Account targetCreator = new PublicKeyAccount(this.repository, targetOrder.getCreatorPublicKey());
-		targetCreator.setConfirmedBalance(targetOrder.getWantAssetId(), targetCreator.getConfirmedBalance(targetOrder.getWantAssetId()).add(tradeData.getInitiatorAmount()));
+		targetCreator.modifyAssetBalance(targetOrder.getWantAssetId(), tradeData.getInitiatorAmount());
 
 		// Possible partial saving to refund to initiator
-		BigDecimal initiatorSaving = this.tradeData.getInitiatorSaving();
-		if (initiatorSaving.compareTo(BigDecimal.ZERO) > 0)
-			initiatingCreator.setConfirmedBalance(initiatingOrder.getHaveAssetId(), initiatingCreator.getConfirmedBalance(initiatingOrder.getHaveAssetId()).add(initiatorSaving));
+		long initiatorSaving = this.tradeData.getInitiatorSaving();
+		if (initiatorSaving > 0)
+			initiatingCreator.modifyAssetBalance(initiatingOrder.getHaveAssetId(), initiatorSaving);
 	}
 
 	public void orphan() throws DataException {
-		AssetRepository assetRepository = this.repository.getAssetRepository();
-
 		// Note: targetAmount is amount traded FROM target order
 		// Note: initiatorAmount is amount traded FROM initiating order
 
-		// Revert corresponding Orders on both sides of trade
 		commonPrep();
 
-		initiatingOrder.setFulfilled(initiatingOrder.getFulfilled().subtract(isNewPricing ? newPricingFulfilled : tradeData.getInitiatorAmount()));
+		// Revert corresponding Orders on both sides of trade
+		initiatingOrder.setFulfilled(initiatingOrder.getFulfilled() - fulfilled);
 		initiatingOrder.setIsFulfilled(Order.isFulfilled(initiatingOrder));
 		// Set isClosed to false if isFulfilled now false
 		initiatingOrder.setIsClosed(initiatingOrder.getIsFulfilled());
 		assetRepository.save(initiatingOrder);
 
-		targetOrder.setFulfilled(targetOrder.getFulfilled().subtract(isNewPricing ? newPricingFulfilled : tradeData.getTargetAmount()));
+		targetOrder.setFulfilled(targetOrder.getFulfilled() - fulfilled);
 		targetOrder.setIsFulfilled(Order.isFulfilled(targetOrder));
 		// Set isClosed to false if isFulfilled now false
 		targetOrder.setIsClosed(targetOrder.getIsFulfilled());
@@ -106,15 +99,15 @@ public class Trade {
 
 		// Reverse asset transfers
 		Account initiatingCreator = new PublicKeyAccount(this.repository, initiatingOrder.getCreatorPublicKey());
-		initiatingCreator.setConfirmedBalance(initiatingOrder.getWantAssetId(), initiatingCreator.getConfirmedBalance(initiatingOrder.getWantAssetId()).subtract(tradeData.getTargetAmount()));
+		initiatingCreator.modifyAssetBalance(initiatingOrder.getWantAssetId(), - tradeData.getTargetAmount());
 
 		Account targetCreator = new PublicKeyAccount(this.repository, targetOrder.getCreatorPublicKey());
-		targetCreator.setConfirmedBalance(targetOrder.getWantAssetId(), targetCreator.getConfirmedBalance(targetOrder.getWantAssetId()).subtract(tradeData.getInitiatorAmount()));
+		targetCreator.modifyAssetBalance(targetOrder.getWantAssetId(), - tradeData.getInitiatorAmount());
 
 		// Possible partial saving to claw back from  initiator
-		BigDecimal initiatorSaving = this.tradeData.getInitiatorSaving();
-		if (initiatorSaving.compareTo(BigDecimal.ZERO) > 0)
-			initiatingCreator.setConfirmedBalance(initiatingOrder.getHaveAssetId(), initiatingCreator.getConfirmedBalance(initiatingOrder.getHaveAssetId()).subtract(initiatorSaving));
+		long initiatorSaving = this.tradeData.getInitiatorSaving();
+		if (initiatorSaving > 0)
+			initiatingCreator.modifyAssetBalance(initiatingOrder.getHaveAssetId(), - initiatorSaving);
 
 		// Remove trade from repository
 		assetRepository.delete(tradeData);

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

@@ -1,11 +1,9 @@
 package org.qortal.at;
 
-import java.math.BigDecimal;
-import java.nio.ByteBuffer;
 import java.util.List;
 
 import org.ciyam.at.MachineState;
-import org.qortal.asset.Asset;
+import org.ciyam.at.Timestamp;
 import org.qortal.crypto.Crypto;
 import org.qortal.data.at.ATData;
 import org.qortal.data.at.ATStateData;
@@ -42,66 +40,28 @@ public class AT {
 		int height = this.repository.getBlockRepository().getBlockchainHeight() + 1;
 		byte[] creatorPublicKey = deployATTransactionData.getCreatorPublicKey();
 		long creation = deployATTransactionData.getTimestamp();
-
-		byte[] creationBytes = deployATTransactionData.getCreationBytes();
 		long assetId = deployATTransactionData.getAssetId();
-		short version = (short) ((creationBytes[0] & 0xff) | (creationBytes[1] << 8)); // Little-endian
 
-		if (version >= 2) {
-			MachineState machineState = new MachineState(deployATTransactionData.getCreationBytes());
+		// Just enough AT data to allow API to query initial balances, etc.
+		ATData skeletonAtData = new ATData(atAddress, creatorPublicKey, creation, assetId);
 
-			this.atData = new ATData(atAddress, creatorPublicKey, creation, machineState.version, assetId, machineState.getCodeBytes(),
-					machineState.getIsSleeping(), machineState.getSleepUntilHeight(), machineState.getIsFinished(), machineState.getHadFatalError(),
-					machineState.getIsFrozen(), machineState.getFrozenBalance());
+		long blockTimestamp = Timestamp.toLong(height, 0);
+		QortalATAPI api = new QortalATAPI(repository, skeletonAtData, blockTimestamp);
+		QortalAtLoggerFactory loggerFactory = QortalAtLoggerFactory.getInstance();
 
-			byte[] stateData = machineState.toBytes();
-			byte[] stateHash = Crypto.digest(stateData);
+		MachineState machineState = new MachineState(api, loggerFactory, deployATTransactionData.getCreationBytes());
 
-			this.atStateData = new ATStateData(atAddress, height, creation, stateData, stateHash, BigDecimal.ZERO.setScale(8));
-		} else {
-			// Legacy v1 AT
-			// We would deploy these in 'dead' state as they will never be run on Qortal
-			// but this breaks import from Qora1 so something else will have to mark them dead at hard-fork
+		byte[] codeBytes = machineState.getCodeBytes();
+		byte[] codeHash = Crypto.digest(codeBytes);
 
-			// Extract code bytes length
-			ByteBuffer byteBuffer = ByteBuffer.wrap(deployATTransactionData.getCreationBytes());
+		this.atData = new ATData(atAddress, creatorPublicKey, creation, machineState.version, assetId, codeBytes, codeHash,
+				machineState.isSleeping(), machineState.getSleepUntilHeight(), machineState.isFinished(), machineState.hadFatalError(),
+				machineState.isFrozen(), machineState.getFrozenBalance());
 
-			// v1 AT header is: version, reserved, code-pages, data-pages, call-stack-pages, user-stack-pages (all shorts)
+		byte[] stateData = machineState.toBytes();
+		byte[] stateHash = Crypto.digest(stateData);
 
-			// Number of code pages
-			short numCodePages = byteBuffer.get(2 + 2);
-
-			// Skip header and also "minimum activation amount" (long)
-			byteBuffer.position(6 * 2 + 8);
-
-			int codeLen = 0;
-
-			// Extract actual code length, stored in minimal-size form (byte, short or int)
-			if (numCodePages * 256 < 257) {
-				codeLen = byteBuffer.get() & 0xff;
-			} else if (numCodePages * 256 < Short.MAX_VALUE + 1) {
-				codeLen = byteBuffer.getShort() & 0xffff;
-			} else if (numCodePages * 256 <= Integer.MAX_VALUE) {
-				codeLen = byteBuffer.getInt();
-			}
-
-			// Extract code bytes
-			byte[] codeBytes = new byte[codeLen];
-			byteBuffer.get(codeBytes);
-
-			// Create AT
-			boolean isSleeping = false;
-			Integer sleepUntilHeight = null;
-			boolean isFinished = false;
-			boolean hadFatalError = false;
-			boolean isFrozen = false;
-			Long frozenBalance = null;
-
-			this.atData = new ATData(atAddress, creatorPublicKey, creation, version, Asset.QORT, codeBytes, isSleeping, sleepUntilHeight, isFinished,
-					hadFatalError, isFrozen, frozenBalance);
-
-			this.atStateData = new ATStateData(atAddress, height, creation, null, null, BigDecimal.ZERO.setScale(8));
-		}
+		this.atStateData = new ATStateData(atAddress, height, stateData, stateHash, 0L, true);
 	}
 
 	// Getters / setters
@@ -116,9 +76,7 @@ public class AT {
 		ATRepository atRepository = this.repository.getATRepository();
 		atRepository.save(this.atData);
 
-		// For version 2+ we also store initial AT state data
-		if (this.atData.getVersion() >= 2)
-			atRepository.save(this.atStateData);
+		atRepository.save(this.atStateData);
 	}
 
 	public void undeploy() throws DataException {
@@ -126,34 +84,80 @@ public class AT {
 		this.repository.getATRepository().delete(this.atData.getATAddress());
 	}
 
-	public List<AtTransaction> run(long blockTimestamp) throws DataException {
+	public List<AtTransaction> run(int blockHeight, long blockTimestamp) throws DataException {
 		String atAddress = this.atData.getATAddress();
 
 		QortalATAPI api = new QortalATAPI(repository, this.atData, blockTimestamp);
-		QortalATLogger logger = new QortalATLogger();
+		QortalAtLoggerFactory loggerFactory = QortalAtLoggerFactory.getInstance();
 
 		byte[] codeBytes = this.atData.getCodeBytes();
 
-		// Fetch latest ATStateData for this AT (if any)
+		// Fetch latest ATStateData for this AT
 		ATStateData latestAtStateData = this.repository.getATRepository().getLatestATState(atAddress);
 
-		// There should be at least initial AT state data
+		// There should be at least initial deployment AT state data
 		if (latestAtStateData == null)
-			throw new IllegalStateException("No initial AT state data found");
+			throw new IllegalStateException("No previous AT state data found");
 
 		// [Re]create AT machine state using AT state data or from scratch as applicable
-		MachineState state = MachineState.fromBytes(api, logger, latestAtStateData.getStateData(), codeBytes);
-		state.execute();
+		MachineState state = MachineState.fromBytes(api, loggerFactory, latestAtStateData.getStateData(), codeBytes);
+		try {
+			state.execute();
+		} catch (Exception e) {
+			throw new DataException(String.format("Uncaught exception while running AT '%s'", atAddress), e);
+		}
 
-		int height = this.repository.getBlockRepository().getBlockchainHeight() + 1;
-		long creation = this.atData.getCreation();
 		byte[] stateData = state.toBytes();
 		byte[] stateHash = Crypto.digest(stateData);
-		BigDecimal atFees = api.calcFinalFees(state);
+		long atFees = api.calcFinalFees(state);
 
-		this.atStateData = new ATStateData(atAddress, height, creation, stateData, stateHash, atFees);
+		this.atStateData = new ATStateData(atAddress, blockHeight, stateData, stateHash, atFees, false);
 
 		return api.getTransactions();
 	}
 
+	public void update(int blockHeight, long blockTimestamp) throws DataException {
+		// Extract minimal/flags-only AT machine state using AT state data
+		MachineState state = MachineState.flagsOnlyfromBytes(this.atStateData.getStateData());
+
+		// Save latest AT state data
+		this.repository.getATRepository().save(this.atStateData);
+
+		// Update AT info in repository too
+		this.atData.setIsSleeping(state.isSleeping());
+		this.atData.setSleepUntilHeight(state.getSleepUntilHeight());
+		this.atData.setIsFinished(state.isFinished());
+		this.atData.setHadFatalError(state.hadFatalError());
+		this.atData.setIsFrozen(state.isFrozen());
+		this.atData.setFrozenBalance(state.getFrozenBalance());
+		this.repository.getATRepository().save(this.atData);
+	}
+
+	public void revert(int blockHeight, long blockTimestamp) throws DataException {
+		String atAddress = this.atData.getATAddress();
+
+		// Delete old AT state data from repository
+		this.repository.getATRepository().delete(atAddress, blockHeight);
+
+		if (this.atStateData.isInitial())
+			return;
+
+		// Load previous state data
+		ATStateData previousStateData = this.repository.getATRepository().getLatestATState(atAddress);
+		if (previousStateData == null)
+			throw new DataException("Can't find previous AT state data for " + atAddress);
+
+		// Extract minimal/flags-only AT machine state using AT state data
+		MachineState state = MachineState.flagsOnlyfromBytes(previousStateData.getStateData());
+
+		// Update AT info in repository
+		this.atData.setIsSleeping(state.isSleeping());
+		this.atData.setSleepUntilHeight(state.getSleepUntilHeight());
+		this.atData.setIsFinished(state.isFinished());
+		this.atData.setHadFatalError(state.hadFatalError());
+		this.atData.setIsFrozen(state.isFrozen());
+		this.atData.setFrozenBalance(state.getFrozenBalance());
+		this.repository.getATRepository().save(this.atData);
+	}
+
 }

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

@@ -1,134 +0,0 @@
-package org.qortal.at;
-
-import static java.util.Arrays.stream;
-import static java.util.stream.Collectors.toMap;
-
-import java.math.BigDecimal;
-import java.util.List;
-import java.util.Map;
-
-import org.ciyam.at.MachineState;
-import org.ciyam.at.Timestamp;
-import org.qortal.account.Account;
-import org.qortal.block.Block;
-import org.qortal.data.block.BlockData;
-import org.qortal.data.transaction.ATTransactionData;
-import org.qortal.data.transaction.PaymentTransactionData;
-import org.qortal.data.transaction.TransactionData;
-import org.qortal.repository.BlockRepository;
-import org.qortal.repository.DataException;
-import org.qortal.transaction.Transaction;
-
-public enum BlockchainAPI {
-
-	QORTAL(0) {
-		@Override
-		public void putTransactionFromRecipientAfterTimestampInA(String recipient, Timestamp timestamp, MachineState state) {
-			int height = timestamp.blockHeight;
-			int sequence = timestamp.transactionSequence + 1;
-
-			QortalATAPI api = (QortalATAPI) state.getAPI();
-			BlockRepository blockRepository = api.repository.getBlockRepository();
-
-			try {
-				Account recipientAccount = new Account(api.repository, recipient);
-
-				while (height <= blockRepository.getBlockchainHeight()) {
-					BlockData blockData = blockRepository.fromHeight(height);
-
-					if (blockData == null)
-						throw new DataException("Unable to fetch block " + height + " from repository?");
-
-					Block block = new Block(api.repository, blockData);
-
-					List<Transaction> transactions = block.getTransactions();
-
-					// No more transactions in this block? Try next block
-					if (sequence >= transactions.size()) {
-						++height;
-						sequence = 0;
-						continue;
-					}
-
-					Transaction transaction = transactions.get(sequence);
-
-					// Transaction needs to be sent to specified recipient
-					if (transaction.getRecipientAccounts().contains(recipientAccount)) {
-						// Found a transaction
-
-						api.setA1(state, new Timestamp(height, timestamp.blockchainId, sequence).longValue());
-
-						// Hash transaction's signature into other three A fields for future verification that it's the same transaction
-						byte[] hash = QortalATAPI.sha192(transaction.getTransactionData().getSignature());
-
-						api.setA2(state, QortalATAPI.fromBytes(hash, 0));
-						api.setA3(state, QortalATAPI.fromBytes(hash, 8));
-						api.setA4(state, QortalATAPI.fromBytes(hash, 16));
-						return;
-					}
-
-					// Transaction wasn't for us - keep going
-					++sequence;
-				}
-
-				// No more transactions - zero A and exit
-				api.zeroA(state);
-			} catch (DataException e) {
-				throw new RuntimeException("AT API unable to fetch next transaction?", e);
-			}
-		}
-
-		@Override
-		public long getAmountFromTransactionInA(Timestamp timestamp, MachineState state) {
-			QortalATAPI api = (QortalATAPI) state.getAPI();
-			TransactionData transactionData = api.fetchTransaction(state);
-
-			switch (transactionData.getType()) {
-				case PAYMENT:
-					return ((PaymentTransactionData) transactionData).getAmount().unscaledValue().longValue();
-
-				case AT:
-					BigDecimal amount = ((ATTransactionData) transactionData).getAmount();
-
-					if (amount != null)
-						return amount.unscaledValue().longValue();
-					else
-						return 0xffffffffffffffffL;
-
-				default:
-					return 0xffffffffffffffffL;
-			}
-		}
-	},
-	BTC(1) {
-		@Override
-		public void putTransactionFromRecipientAfterTimestampInA(String recipient, Timestamp timestamp, MachineState state) {
-			// TODO BTC transaction support for ATv2
-		}
-
-		@Override
-		public long getAmountFromTransactionInA(Timestamp timestamp, MachineState state) {
-			// TODO BTC transaction support for ATv2
-			return 0;
-		}
-	};
-
-	public final int value;
-
-	private static final Map<Integer, BlockchainAPI> map = stream(BlockchainAPI.values()).collect(toMap(type -> type.value, type -> type));
-
-	BlockchainAPI(int value) {
-		this.value = value;
-	}
-
-	public static BlockchainAPI valueOf(int value) {
-		return map.get(value);
-	}
-
-	// Blockchain-specific API methods
-
-	public abstract void putTransactionFromRecipientAfterTimestampInA(String recipient, Timestamp timestamp, MachineState state);
-
-	public abstract long getAmountFromTransactionInA(Timestamp timestamp, MachineState state);
-
-}

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

@@ -1,11 +1,11 @@
 package org.qortal.at;
 
-import java.math.BigDecimal;
-import java.security.MessageDigest;
-import java.security.NoSuchAlgorithmException;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
 
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.ciyam.at.API;
 import org.ciyam.at.ExecutionException;
 import org.ciyam.at.FunctionData;
@@ -14,35 +14,41 @@ import org.ciyam.at.MachineState;
 import org.ciyam.at.OpCode;
 import org.ciyam.at.Timestamp;
 import org.qortal.account.Account;
-import org.qortal.account.GenesisAccount;
+import org.qortal.account.NullAccount;
 import org.qortal.account.PublicKeyAccount;
 import org.qortal.asset.Asset;
+import org.qortal.block.BlockChain;
+import org.qortal.block.BlockChain.CiyamAtSettings;
 import org.qortal.crypto.Crypto;
 import org.qortal.data.at.ATData;
 import org.qortal.data.block.BlockData;
+import org.qortal.data.block.BlockSummaryData;
 import org.qortal.data.transaction.ATTransactionData;
 import org.qortal.data.transaction.BaseTransactionData;
 import org.qortal.data.transaction.MessageTransactionData;
+import org.qortal.data.transaction.PaymentTransactionData;
 import org.qortal.data.transaction.TransactionData;
 import org.qortal.group.Group;
+import org.qortal.repository.ATRepository;
 import org.qortal.repository.DataException;
 import org.qortal.repository.Repository;
 import org.qortal.transaction.AtTransaction;
+import org.qortal.transaction.Transaction.TransactionType;
+import org.qortal.utils.Base58;
+import org.qortal.utils.BitTwiddling;
 
 import com.google.common.primitives.Bytes;
 
 public class QortalATAPI extends API {
 
-	// Useful constants
-	private static final BigDecimal FEE_PER_STEP = BigDecimal.valueOf(1.0).setScale(8); // 1 QORT per "step"
-	private static final int MAX_STEPS_PER_ROUND = 500;
-	private static final int STEPS_PER_FUNCTION_CALL = 10;
-	private static final int MINUTES_PER_BLOCK = 10;
+	private static final byte[] ADDRESS_PADDING = new byte[32 - Account.ADDRESS_LENGTH];
+	private static final Logger LOGGER = LogManager.getLogger(QortalATAPI.class);
 
 	// Properties
-	Repository repository;
-	ATData atData;
-	long blockTimestamp;
+	private Repository repository;
+	private ATData atData;
+	private long blockTimestamp;
+	private final CiyamAtSettings ciyamAtSettings;
 
 	/** List of generated AT transactions */
 	List<AtTransaction> transactions;
@@ -54,36 +60,42 @@ public class QortalATAPI extends API {
 		this.atData = atData;
 		this.transactions = new ArrayList<>();
 		this.blockTimestamp = blockTimestamp;
+
+		this.ciyamAtSettings = BlockChain.getInstance().getCiyamAtSettings();
 	}
 
 	// Methods specific to Qortal AT processing, not inherited
 
+	public Repository getRepository() {
+		return this.repository;
+	}
+
 	public List<AtTransaction> getTransactions() {
 		return this.transactions;
 	}
 
-	public BigDecimal calcFinalFees(MachineState state) {
-		return FEE_PER_STEP.multiply(BigDecimal.valueOf(state.getSteps()));
+	public long calcFinalFees(MachineState state) {
+		return state.getSteps() * this.ciyamAtSettings.feePerStep;
 	}
 
 	// Inherited methods from CIYAM AT API
 
 	@Override
 	public int getMaxStepsPerRound() {
-		return MAX_STEPS_PER_ROUND;
+		return this.ciyamAtSettings.maxStepsPerRound;
 	}
 
 	@Override
 	public int getOpCodeSteps(OpCode opcode) {
 		if (opcode.value >= OpCode.EXT_FUN.value && opcode.value <= OpCode.EXT_FUN_RET_DAT_2.value)
-			return STEPS_PER_FUNCTION_CALL;
+			return this.ciyamAtSettings.stepsPerFunctionCall;
 
 		return 1;
 	}
 
 	@Override
 	public long getFeePerStep() {
-		return FEE_PER_STEP.unscaledValue().longValue();
+		return this.ciyamAtSettings.feePerStep;
 	}
 
 	@Override
@@ -105,31 +117,67 @@ public class QortalATAPI extends API {
 	}
 
 	@Override
-	public void putPreviousBlockHashInA(MachineState state) {
+	public void putPreviousBlockHashIntoA(MachineState state) {
 		try {
-			BlockData blockData = this.repository.getBlockRepository().fromHeight(this.getPreviousBlockHeight());
+			int previousBlockHeight = this.repository.getBlockRepository().getBlockchainHeight() - 1;
+
+			// We only need signature, so only request a block summary
+			List<BlockSummaryData> blockSummaries = this.repository.getBlockRepository().getBlockSummaries(previousBlockHeight, previousBlockHeight);
+			if (blockSummaries == null || blockSummaries.size() != 1)
+				throw new RuntimeException("AT API unable to fetch previous block hash?");
 
 			// Block's signature is 128 bytes so we need to reduce this to 4 longs (32 bytes)
-			byte[] blockHash = Crypto.digest(blockData.getSignature());
+			// To be able to use hash to look up block, save height (8 bytes) and partial signature (24 bytes)
+			this.setA1(state, previousBlockHeight);
 
-			this.setA(state, blockHash);
+			byte[] signature = blockSummaries.get(0).getSignature();
+			// Save some of minter's signature and transactions signature, so middle 24 bytes of the full 128 byte signature.
+			this.setA2(state, BitTwiddling.longFromBEBytes(signature, 52));
+			this.setA3(state, BitTwiddling.longFromBEBytes(signature, 60));
+			this.setA4(state, BitTwiddling.longFromBEBytes(signature, 68));
 		} catch (DataException e) {
 			throw new RuntimeException("AT API unable to fetch previous block?", e);
 		}
 	}
 
 	@Override
-	public void putTransactionAfterTimestampInA(Timestamp timestamp, MachineState state) {
+	public void putTransactionAfterTimestampIntoA(Timestamp timestamp, MachineState state) {
 		// Recipient is this AT
-		String recipient = this.atData.getATAddress();
+		String atAddress = this.atData.getATAddress();
 
-		BlockchainAPI blockchainAPI = BlockchainAPI.valueOf(timestamp.blockchainId);
-		blockchainAPI.putTransactionFromRecipientAfterTimestampInA(recipient, timestamp, state);
+		int height = timestamp.blockHeight;
+		int sequence = timestamp.transactionSequence;
+
+		if (state.getCurrentBlockHeight() < BlockChain.getInstance().getAtFindNextTransactionFixHeight())
+			// Off-by-one bug still in effect
+			sequence += 1;
+
+		ATRepository.NextTransactionInfo nextTransactionInfo;
+		try {
+			nextTransactionInfo = this.getRepository().getATRepository().findNextTransaction(atAddress, height, sequence);
+		} catch (DataException e) {
+			throw new RuntimeException("AT API unable to fetch next transaction?", e);
+		}
+
+		if (nextTransactionInfo == null) {
+			// No more transactions for AT at this time - zero A and exit
+			this.zeroA(state);
+			return;
+		}
+
+		// Found a transaction
+
+		this.setA1(state, new Timestamp(nextTransactionInfo.height, timestamp.blockchainId, nextTransactionInfo.sequence).longValue());
+
+		// Copy transaction's partial signature into the other three A fields for future verification that it's the same transaction
+		this.setA2(state, BitTwiddling.longFromBEBytes(nextTransactionInfo.signature, 8));
+		this.setA3(state, BitTwiddling.longFromBEBytes(nextTransactionInfo.signature, 16));
+		this.setA4(state, BitTwiddling.longFromBEBytes(nextTransactionInfo.signature, 24));
 	}
 
 	@Override
 	public long getTypeFromTransactionInA(MachineState state) {
-		TransactionData transactionData = this.fetchTransaction(state);
+		TransactionData transactionData = this.getTransactionFromA(state);
 
 		switch (transactionData.getType()) {
 			case PAYMENT:
@@ -151,22 +199,36 @@ public class QortalATAPI extends API {
 
 	@Override
 	public long getAmountFromTransactionInA(MachineState state) {
-		Timestamp timestamp = new Timestamp(state.getA1());
-		BlockchainAPI blockchainAPI = BlockchainAPI.valueOf(timestamp.blockchainId);
-		return blockchainAPI.getAmountFromTransactionInA(timestamp, state);
+		TransactionData transactionData = this.getTransactionFromA(state);
+
+		switch (transactionData.getType()) {
+			case PAYMENT:
+				return ((PaymentTransactionData) transactionData).getAmount();
+
+			case AT:
+				Long amount = ((ATTransactionData) transactionData).getAmount();
+
+				if (amount != null)
+					return amount;
+
+				// fall-through to default
+
+			default:
+				return 0xffffffffffffffffL;
+		}
 	}
 
 	@Override
 	public long getTimestampFromTransactionInA(MachineState state) {
 		// Transaction's "timestamp" already stored in A1
-		Timestamp timestamp = new Timestamp(state.getA1());
+		Timestamp timestamp = new Timestamp(this.getA1(state));
 		return timestamp.longValue();
 	}
 
 	@Override
 	public long generateRandomUsingTransactionInA(MachineState state) {
-		// The plan here is to sleep for a block then use next block's signature and this transaction's signature to generate pseudo-random, but deterministic,
-		// value.
+		// The plan here is to sleep for a block then use next block's signature
+		// and this transaction's signature to generate pseudo-random, but deterministic, value.
 
 		if (!isFirstOpCodeAfterSleeping(state)) {
 			// First call
@@ -179,7 +241,7 @@ public class QortalATAPI extends API {
 			// Second call
 
 			// HASH(A and new block hash)
-			TransactionData transactionData = this.fetchTransaction(state);
+			TransactionData transactionData = this.getTransactionFromA(state);
 
 			try {
 				BlockData blockData = this.repository.getBlockRepository().getLastBlock();
@@ -191,7 +253,7 @@ public class QortalATAPI extends API {
 
 				byte[] hash = Crypto.digest(input);
 
-				return fromBytes(hash, 0);
+				return BitTwiddling.longFromBEBytes(hash, 0);
 			} catch (DataException e) {
 				throw new RuntimeException("AT API unable to fetch latest block from repository?", e);
 			}
@@ -203,50 +265,50 @@ public class QortalATAPI extends API {
 		// Zero B in case of issues or shorter-than-B message
 		this.zeroB(state);
 
-		TransactionData transactionData = this.fetchTransaction(state);
+		TransactionData transactionData = this.getTransactionFromA(state);
 
-		byte[] messageData = null;
-
-		switch (transactionData.getType()) {
-			case MESSAGE:
-				messageData = ((MessageTransactionData) transactionData).getData();
-				break;
-
-			case AT:
-				messageData = ((ATTransactionData) transactionData).getMessage();
-				break;
-
-			default:
-				return;
-		}
-
-		// Check data length is appropriate, i.e. not larger than B
-		if (messageData.length > 4 * 8)
-			return;
+		byte[] messageData = this.getMessageFromTransaction(transactionData);
 
 		// Pad messageData to fit B
-		byte[] paddedMessageData = Bytes.ensureCapacity(messageData, 4 * 8, 0);
+		if (messageData.length < 4 * 8)
+			messageData = Bytes.ensureCapacity(messageData, 4 * 8, 0);
 
 		// Endian must be correct here so that (for example) a SHA256 message can be compared to one generated locally
-		this.setB(state, paddedMessageData);
+		this.setB(state, messageData);
 	}
 
 	@Override
 	public void putAddressFromTransactionInAIntoB(MachineState state) {
-		TransactionData transactionData = this.fetchTransaction(state);
+		TransactionData transactionData = this.getTransactionFromA(state);
 
-		// We actually use public key as it has more potential utility (e.g. message verification) than an address
-		byte[] bytes = transactionData.getCreatorPublicKey();
+		String address;
+		if (transactionData.getType() == TransactionType.AT) {
+			// Use AT address from transaction data, as transaction's public key will always be fake
+			address = ((ATTransactionData) transactionData).getATAddress();
+		} else {
+			byte[] publicKey = transactionData.getCreatorPublicKey();
+			address = Crypto.toAddress(publicKey);
+		}
 
-		this.setB(state, bytes);
+		// Convert to byte form as this only takes 25 bytes,
+		// compared to string-form's 34 bytes,
+		// and we only have 32 bytes available.
+		byte[] addressBytes = Bytes.ensureCapacity(Base58.decode(address), 32, 0); // pad to 32 bytes
+
+		this.setB(state, addressBytes);
 	}
 
 	@Override
 	public void putCreatorAddressIntoB(MachineState state) {
-		// We actually use public key as it has more potential utility (e.g. message verification) than an address
-		byte[] bytes = atData.getCreatorPublicKey();
+		byte[] publicKey = atData.getCreatorPublicKey();
+		String address = Crypto.toAddress(publicKey);
 
-		this.setB(state, bytes);
+		// Convert to byte form as this only takes 25 bytes,
+		// compared to string-form's 34 bytes,
+		// and we only have 32 bytes available.
+		byte[] addressBytes = Bytes.ensureCapacity(Base58.decode(address), 32, 0); // pad to 32 bytes
+
+		this.setB(state, addressBytes);
 	}
 
 	@Override
@@ -254,25 +316,22 @@ public class QortalATAPI extends API {
 		try {
 			Account atAccount = this.getATAccount();
 
-			return atAccount.getConfirmedBalance(Asset.QORT).unscaledValue().longValue();
+			return atAccount.getConfirmedBalance(Asset.QORT);
 		} catch (DataException e) {
 			throw new RuntimeException("AT API unable to fetch AT's current balance?", e);
 		}
 	}
 
 	@Override
-	public void payAmountToB(long unscaledAmount, MachineState state) {
-		byte[] publicKey = state.getB();
-
-		PublicKeyAccount recipient = new PublicKeyAccount(this.repository, publicKey);
+	public void payAmountToB(long amount, MachineState state) {
+		Account recipient = getAccountFromB(state);
 
 		long timestamp = this.getNextTransactionTimestamp();
 		byte[] reference = this.getLastReference();
-		BigDecimal amount = BigDecimal.valueOf(unscaledAmount, 8);
 
-		BaseTransactionData baseTransactionData = new BaseTransactionData(timestamp, Group.NO_GROUP, reference, GenesisAccount.PUBLIC_KEY, BigDecimal.ZERO, null);
+		BaseTransactionData baseTransactionData = new BaseTransactionData(timestamp, Group.NO_GROUP, reference, NullAccount.PUBLIC_KEY, 0L, null);
 		ATTransactionData atTransactionData = new ATTransactionData(baseTransactionData, this.atData.getATAddress(),
-				recipient.getAddress(), amount, this.atData.getAssetId(), new byte[0]);
+				recipient.getAddress(), amount, this.atData.getAssetId());
 		AtTransaction atTransaction = new AtTransaction(this.repository, atTransactionData);
 
 		// Add to our transactions
@@ -281,17 +340,15 @@ public class QortalATAPI extends API {
 
 	@Override
 	public void messageAToB(MachineState state) {
-		byte[] message = state.getA();
-		byte[] publicKey = state.getB();
-
-		PublicKeyAccount recipient = new PublicKeyAccount(this.repository, publicKey);
+		byte[] message = this.getA(state);
+		Account recipient = getAccountFromB(state);
 
 		long timestamp = this.getNextTransactionTimestamp();
 		byte[] reference = this.getLastReference();
 
-		BaseTransactionData baseTransactionData = new BaseTransactionData(timestamp, Group.NO_GROUP, reference, GenesisAccount.PUBLIC_KEY, BigDecimal.ZERO, null);
+		BaseTransactionData baseTransactionData = new BaseTransactionData(timestamp, Group.NO_GROUP, reference, NullAccount.PUBLIC_KEY, 0L, null);
 		ATTransactionData atTransactionData = new ATTransactionData(baseTransactionData, this.atData.getATAddress(),
-				recipient.getAddress(), BigDecimal.ZERO, this.atData.getAssetId(), message);
+				recipient.getAddress(), message);
 		AtTransaction atTransaction = new AtTransaction(this.repository, atTransactionData);
 
 		// Add to our transactions
@@ -303,22 +360,24 @@ public class QortalATAPI extends API {
 		int blockHeight = timestamp.blockHeight;
 
 		// At least one block in the future
-		blockHeight += (minutes / MINUTES_PER_BLOCK) + 1;
+		blockHeight += Math.max(minutes / this.ciyamAtSettings.minutesPerBlock, 1);
 
 		return new Timestamp(blockHeight, 0).longValue();
 	}
 
 	@Override
 	public void onFinished(long finalBalance, MachineState state) {
+		if (finalBalance <= 0)
+			return;
+
 		// Refund remaining balance (if any) to AT's creator
 		Account creator = this.getCreator();
 		long timestamp = this.getNextTransactionTimestamp();
 		byte[] reference = this.getLastReference();
-		BigDecimal amount = BigDecimal.valueOf(finalBalance, 8);
 
-		BaseTransactionData baseTransactionData = new BaseTransactionData(timestamp, Group.NO_GROUP, reference, GenesisAccount.PUBLIC_KEY, BigDecimal.ZERO, null);
+		BaseTransactionData baseTransactionData = new BaseTransactionData(timestamp, Group.NO_GROUP, reference, NullAccount.PUBLIC_KEY, 0L, null);
 		ATTransactionData atTransactionData = new ATTransactionData(baseTransactionData, this.atData.getATAddress(),
-				creator.getAddress(), amount, this.atData.getAssetId(), new byte[0]);
+				creator.getAddress(), finalBalance, this.atData.getAssetId());
 		AtTransaction atTransaction = new AtTransaction(this.repository, atTransactionData);
 
 		// Add to our transactions
@@ -327,7 +386,7 @@ public class QortalATAPI extends API {
 
 	@Override
 	public void onFatalError(MachineState state, ExecutionException e) {
-		state.getLogger().error("AT " + this.atData.getATAddress() + " suffered fatal error: " + e.getMessage());
+		LOGGER.error("AT " + this.atData.getATAddress() + " suffered fatal error: " + e.getMessage());
 	}
 
 	@Override
@@ -338,47 +397,38 @@ public class QortalATAPI extends API {
 		if (qortalFunctionCode == null)
 			throw new IllegalFunctionCodeException("Unknown Qortal function code 0x" + String.format("%04x", rawFunctionCode) + " encountered");
 
-		qortalFunctionCode.preExecuteCheck(2, true, state, rawFunctionCode);
+		qortalFunctionCode.preExecuteCheck(paramCount, returnValueExpected, rawFunctionCode);
 	}
 
 	@Override
 	public void platformSpecificPostCheckExecute(FunctionData functionData, MachineState state, short rawFunctionCode) throws ExecutionException {
 		QortalFunctionCode qortalFunctionCode = QortalFunctionCode.valueOf(rawFunctionCode);
 
+		if (qortalFunctionCode == null)
+			throw new IllegalFunctionCodeException("Unknown Qortal function code 0x" + String.format("%04x", rawFunctionCode) + " encountered");
+
 		qortalFunctionCode.execute(functionData, state, rawFunctionCode);
 	}
 
 	// Utility methods
 
-	/** Convert part of little-endian byte[] to long */
-	/* package */ static long fromBytes(byte[] bytes, int start) {
-		return (bytes[start] & 0xffL) | (bytes[start + 1] & 0xffL) << 8 | (bytes[start + 2] & 0xffL) << 16 | (bytes[start + 3] & 0xffL) << 24
-				| (bytes[start + 4] & 0xffL) << 32 | (bytes[start + 5] & 0xffL) << 40 | (bytes[start + 6] & 0xffL) << 48 | (bytes[start + 7] & 0xffL) << 56;
+	/** Returns partial transaction signature, used to verify we're operating on the same transaction and not naively using block height & sequence. */
+	public static byte[] partialSignature(byte[] fullSignature) {
+		return Arrays.copyOfRange(fullSignature, 8, 32);
 	}
 
-	/** Returns SHA2-192 digest of input - used to verify transaction signatures */
-	public static byte[] sha192(byte[] input) {
-		try {
-			// SHA2-192
-			MessageDigest sha192 = MessageDigest.getInstance("SHA-192");
-			return sha192.digest(input);
-		} catch (NoSuchAlgorithmException e) {
-			throw new RuntimeException("SHA-192 not available");
-		}
-	}
+	/** Verify transaction's partial signature matches A2 thru A4 */
+	private void verifyTransaction(TransactionData transactionData, MachineState state) {
+		// Compare end of transaction's signature against A2 thru A4
+		byte[] sig = transactionData.getSignature();
 
-	/** Verify transaction's SHA2-192 hashed signature matches A2 thru A4 */
-	private static void verifyTransaction(TransactionData transactionData, MachineState state) {
-		// Compare SHA2-192 of transaction's signature against A2 thru A4
-		byte[] hash = sha192(transactionData.getSignature());
-
-		if (state.getA2() != fromBytes(hash, 0) || state.getA3() != fromBytes(hash, 8) || state.getA4() != fromBytes(hash, 16))
+		if (this.getA2(state) != BitTwiddling.longFromBEBytes(sig, 8) || this.getA3(state) != BitTwiddling.longFromBEBytes(sig, 16) || this.getA4(state) != BitTwiddling.longFromBEBytes(sig, 24))
 			throw new IllegalStateException("Transaction signature in A no longer matches signature from repository");
 	}
 
 	/** Returns transaction data from repository using block height & sequence from A1, checking the transaction signatures match too */
-	/* package */ TransactionData fetchTransaction(MachineState state) {
-		Timestamp timestamp = new Timestamp(state.getA1());
+	/* package */ TransactionData getTransactionFromA(MachineState state) {
+		Timestamp timestamp = new Timestamp(this.getA1(state));
 
 		try {
 			TransactionData transactionData = this.repository.getTransactionRepository().fromHeightAndSequence(timestamp.blockHeight,
@@ -396,6 +446,20 @@ public class QortalATAPI extends API {
 		}
 	}
 
+	/** Returns message data from transaction. */
+	/*package*/ byte[] getMessageFromTransaction(TransactionData transactionData) {
+		switch (transactionData.getType()) {
+			case MESSAGE:
+				return ((MessageTransactionData) transactionData).getData();
+
+			case AT:
+				return ((ATTransactionData) transactionData).getMessage();
+
+			default:
+				return null;
+		}
+	}
+
 	/** Returns AT's account */
 	/* package */ Account getATAccount() {
 		return new Account(this.repository, this.atData.getATAddress());
@@ -409,29 +473,17 @@ public class QortalATAPI extends API {
 	/** Returns the timestamp to use for next AT Transaction */
 	private long getNextTransactionTimestamp() {
 		/*
-		 * Timestamp is block's timestamp + position in AT-Transactions list.
+		 * Use block's timestamp.
 		 * 
-		 * We need increasing timestamps to preserve transaction order and hence a correct signature-reference chain when the block is processed.
-		 * 
-		 * As Qora blocks must share the same milliseconds component in their timestamps, this allows us to generate up to 1,000 AT-Transactions per AT without
-		 * issue.
-		 * 
-		 * As long as ATs are not allowed to generate that many per block, e.g. by limiting maximum steps per execution round, then we should be fine.
+		 * This is OK because AT transactions are always generated locally and order is preserved in Transaction.getDataComparator().
 		 */
-
-		// XXX THE ABOVE IS NO LONGER TRUE IN QORTAL!
-		// return this.blockTimestamp + this.transactions.size();
-		throw new RuntimeException("AT timestamp code not fixed!");
+		return this.blockTimestamp;
 	}
 
-	/** Returns AT account's lastReference, taking newly generated ATTransactions into account */
+	/** Returns AT account's lastReference */
 	private byte[] getLastReference() {
-		// Use signature from last AT Transaction we generated
-		if (!this.transactions.isEmpty())
-			return this.transactions.get(this.transactions.size() - 1).getTransactionData().getSignature();
-
 		try {
-			// No transactions yet, so look up AT's account's last reference from repository
+			// Look up AT's account's last reference from repository
 			Account atAccount = this.getATAccount();
 
 			return atAccount.getLastReference();
@@ -440,4 +492,42 @@ public class QortalATAPI extends API {
 		}
 	}
 
+	/**
+	 * Returns Account (possibly PublicKeyAccount) based on value in B.
+	 * <p>
+	 * If first byte in B starts with either address version bytes,<br>
+	 * and bytes 26 to 32 are zero, then use as an address, but only if valid.
+	 * <p>
+	 * Otherwise, assume B is a public key.
+	 */
+	private Account getAccountFromB(MachineState state) {
+		byte[] bBytes = this.getB(state);
+
+		if ((bBytes[0] == Crypto.ADDRESS_VERSION || bBytes[0] == Crypto.AT_ADDRESS_VERSION)
+				&& Arrays.mismatch(bBytes, Account.ADDRESS_LENGTH, 32, ADDRESS_PADDING, 0, ADDRESS_PADDING.length) == -1) {
+			// Extract only the bytes containing address
+			byte[] addressBytes = Arrays.copyOf(bBytes, Account.ADDRESS_LENGTH);
+			// If address (in byte form) is valid...
+			if (Crypto.isValidAddress(addressBytes))
+				// ...then return an Account using address (converted to Base58
+				return new Account(this.repository, Base58.encode(addressBytes));
+		}
+
+		return new PublicKeyAccount(this.repository, bBytes);
+	}
+
+	/* Convenience methods to allow QortalFunctionCode package-visibility access to A/B-get/set methods. */
+
+	protected byte[] getB(MachineState state) {
+		return super.getB(state);
+	}
+
+	protected void setB(MachineState state, byte[] bBytes) {
+		super.setB(state, bBytes);
+	}
+
+	protected void zeroB(MachineState state) {
+		super.zeroB(state);
+	}
+
 }

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

@@ -1,26 +0,0 @@
-package org.qortal.at;
-
-import org.apache.logging.log4j.LogManager;
-import org.apache.logging.log4j.Logger;
-
-public class QortalATLogger implements org.ciyam.at.LoggerInterface {
-
-	// NOTE: We're logging on behalf of org.qortal.at.AT, not ourselves!
-	private static final Logger LOGGER = LogManager.getLogger(AT.class);
-
-	@Override
-	public void error(String message) {
-		LOGGER.error(message);
-	}
-
-	@Override
-	public void debug(String message) {
-		LOGGER.debug(message);
-	}
-
-	@Override
-	public void echo(String message) {
-		LOGGER.info(message);
-	}
-
-}