After successful migration from SQLite or MySql, there is an error after a restart

* UI updates

* Updates modes and calculation

* Unify tip buttons

* White caret

* Add top margin to calculation

* Add space between mode buttons and keypad

* Discount updates

.circleci/can-build.sh

@@ -0,0 +1,6 @@
+#!/bin/sh
+set -e
+
+echo "Checking if it is possible to build Bitcoin only..."
+cd ../BTCPayServer.Tests
+docker-compose -f "docker-compose.yml" build

.circleci/config.yml

@@ -2,15 +2,15 @@ version: 2
 jobs:
   fast_tests:
     machine:
-        enabled: true
+      image: ubuntu-2004:202111-02
     steps:
       - checkout
       - run:
           command: |
-            cd .circleci && ./run-tests.sh "Fast=Fast"
+            cd .circleci && ./run-tests.sh "Fast=Fast|ThirdParty=ThirdParty" && ./can-build.sh
   selenium_tests:
     machine:
-        enabled: true
+      image: ubuntu-2004:202111-02
     steps:
       - checkout
       - run:
@@ -18,79 +18,77 @@ jobs:
             cd .circleci && ./run-tests.sh "Selenium=Selenium"
   integration_tests:
     machine:
-        enabled: true
+      image: ubuntu-2004:202111-02
     steps:
       - checkout
       - run:
           command: |
             cd .circleci && ./run-tests.sh "Integration=Integration"
-  external_tests:
+  trigger_docs_build:
     machine:
-        enabled: true
+      image: ubuntu-2004:202111-02
     steps:
-      - checkout
       - run:
           command: |
-            if [ "$CIRCLE_PROJECT_USERNAME" == "btcpayserver" ] && [ "$CIRCLE_PROJECT_REPONAME" == "btcpayserver" ]; then
-                cd .circleci && ./run-tests.sh "ExternalIntegration=ExternalIntegration"
-            else
-              echo "Skipping running ExternalIntegration tests outside of context of main user and repository that have access to secrets"
-            fi
-
+            curl -X POST -H "Authorization: token $GH_PAT" -H "Accept: application/vnd.github.everest-preview+json" -H "Content-Type: application/json" https://api.github.com/repos/btcpayserver/btcpayserver-doc/dispatches --data '{"event_type": "build_docs"}'
 
   # publish jobs require $DOCKERHUB_REPO, $DOCKERHUB_USER, $DOCKERHUB_PASS defined
   amd64:
     machine:
-        enabled: true
+      image: ubuntu-2004:202111-02
     steps:
-      - checkout  
+      - checkout
       - run:
           command: |
             LATEST_TAG=${CIRCLE_TAG:1} #trim v from tag
+            GIT_COMMIT=$(git rev-parse HEAD)
             #
-            sudo docker build --pull -t $DOCKERHUB_REPO:$LATEST_TAG-amd64 -f amd64.Dockerfile .
+            sudo docker build --build-arg GIT_COMMIT=${GIT_COMMIT} --pull -t $DOCKERHUB_REPO:$LATEST_TAG-amd64 -f amd64.Dockerfile .
+            sudo docker build --build-arg GIT_COMMIT=${GIT_COMMIT} --pull --build-arg CONFIGURATION_NAME=Altcoins-Release -t $DOCKERHUB_REPO:$LATEST_TAG-altcoins-amd64 -f amd64.Dockerfile .
             sudo docker login --username=$DOCKERHUB_USER --password=$DOCKERHUB_PASS
             sudo docker push $DOCKERHUB_REPO:$LATEST_TAG-amd64
+            sudo docker push $DOCKERHUB_REPO:$LATEST_TAG-altcoins-amd64
 
   arm32v7:
     machine:
-        enabled: true
+      image: ubuntu-2004:202111-02
     steps:
-      - checkout  
+      - checkout
       - run:
           command: |
             sudo docker run --rm --privileged multiarch/qemu-user-static:register --reset
             LATEST_TAG=${CIRCLE_TAG:1} #trim v from tag
+            GIT_COMMIT=$(git rev-parse HEAD)
             #
-            sudo docker build --pull -t $DOCKERHUB_REPO:$LATEST_TAG-arm32v7 -f arm32v7.Dockerfile .
+            sudo docker build --build-arg GIT_COMMIT=${GIT_COMMIT} --pull -t $DOCKERHUB_REPO:$LATEST_TAG-arm32v7 -f arm32v7.Dockerfile .
+            sudo docker build --build-arg GIT_COMMIT=${GIT_COMMIT} --pull --build-arg CONFIGURATION_NAME=Altcoins-Release -t $DOCKERHUB_REPO:$LATEST_TAG-altcoins-arm32v7 -f arm32v7.Dockerfile .
             sudo docker login --username=$DOCKERHUB_USER --password=$DOCKERHUB_PASS
             sudo docker push $DOCKERHUB_REPO:$LATEST_TAG-arm32v7
+            sudo docker push $DOCKERHUB_REPO:$LATEST_TAG-altcoins-arm32v7
 
   arm64v8:
     machine:
-        enabled: true
+      image: ubuntu-2004:202111-02
     steps:
-      - checkout  
+      - checkout
       - run:
           command: |
             sudo docker run --rm --privileged multiarch/qemu-user-static:register --reset
             LATEST_TAG=${CIRCLE_TAG:1} #trim v from tag
+            GIT_COMMIT=$(git rev-parse HEAD)
             #
-            sudo docker build --pull -t $DOCKERHUB_REPO:$LATEST_TAG-arm64v8 -f arm64v8.Dockerfile .
+            sudo docker build --build-arg GIT_COMMIT=${GIT_COMMIT} --pull -t $DOCKERHUB_REPO:$LATEST_TAG-arm64v8 -f arm64v8.Dockerfile .
+            sudo docker build --build-arg GIT_COMMIT=${GIT_COMMIT} --build-arg CONFIGURATION_NAME=Altcoins-Release --pull -t $DOCKERHUB_REPO:$LATEST_TAG-altcoins-arm64v8 -f arm64v8.Dockerfile .
             sudo docker login --username=$DOCKERHUB_USER --password=$DOCKERHUB_PASS
             sudo docker push $DOCKERHUB_REPO:$LATEST_TAG-arm64v8
+            sudo docker push $DOCKERHUB_REPO:$LATEST_TAG-altcoins-arm64v8
 
   multiarch:
     machine:
-      enabled: true
-      image: circleci/classic:201808-01
+      image: ubuntu-2004:202201-02
     steps:
       - run:
           command: |
-            # Turn on Experimental features
-            sudo mkdir $HOME/.docker
-            sudo sh -c 'echo "{ \"experimental\": \"enabled\" }" >> $HOME/.docker/config.json'
-            #
             sudo docker login --username=$DOCKERHUB_USER --password=$DOCKERHUB_PASS
             #
             LATEST_TAG=${CIRCLE_TAG:1} #trim v from tag
@@ -100,6 +98,12 @@ jobs:
             sudo docker manifest annotate $DOCKERHUB_REPO:$LATEST_TAG $DOCKERHUB_REPO:$LATEST_TAG-arm64v8 --os linux --arch arm64 --variant v8
             sudo docker manifest push $DOCKERHUB_REPO:$LATEST_TAG -p
 
+            sudo docker manifest create --amend $DOCKERHUB_REPO:$LATEST_TAG-altcoins $DOCKERHUB_REPO:$LATEST_TAG-altcoins-amd64 $DOCKERHUB_REPO:$LATEST_TAG-altcoins-arm32v7 $DOCKERHUB_REPO:$LATEST_TAG-altcoins-arm64v8
+            sudo docker manifest annotate $DOCKERHUB_REPO:$LATEST_TAG-altcoins $DOCKERHUB_REPO:$LATEST_TAG-altcoins-amd64 --os linux --arch amd64
+            sudo docker manifest annotate $DOCKERHUB_REPO:$LATEST_TAG-altcoins $DOCKERHUB_REPO:$LATEST_TAG-altcoins-arm32v7 --os linux --arch arm --variant v7
+            sudo docker manifest annotate $DOCKERHUB_REPO:$LATEST_TAG-altcoins $DOCKERHUB_REPO:$LATEST_TAG-altcoins-arm64v8 --os linux --arch arm64 --variant v8
+            sudo docker manifest push $DOCKERHUB_REPO:$LATEST_TAG-altcoins -p
+
 workflows:
   version: 2
   build_and_test:
@@ -107,34 +111,37 @@ workflows:
       - fast_tests
       - selenium_tests
       - integration_tests
-      - external_tests:
-          filters:
-            branches:
-                only: master
-
   publish:
     jobs:
+      - trigger_docs_build:
+          filters:
+            branches:
+              ignore: /.*/
+            # only act on version tags
+            tags:
+              only: /(v[1-9]+(\.[0-9]+)*(-[a-z0-9-]+)?)|(v[a-z0-9-]+)/
       - amd64:
           filters:
             # ignore any commit on any branch by default
             branches:
               ignore: /.*/
-            # only act on version tags v1.0.0.88
+            # only act on version tags v1.0.0.88 or v1.0.2-1
             # OR feature tags like vlndseedbackup
+            # OR features on specific versions like v1.0.0.88-lndseedbackup-1
             tags:
-              only: /(v[1-9]+(\.[0-9]+)*)|(v[a-z]+)/
+              only: /(v[1-9]+(\.[0-9]+)*(-[a-z0-9-]+)?)|(v[a-z0-9-]+)/
       - arm32v7:
           filters:
             branches:
               ignore: /.*/
             tags:
-              only: /(v[1-9]+(\.[0-9]+)*)|(v[a-z]+)/
+              only: /(v[1-9]+(\.[0-9]+)*(-[a-z0-9-]+)?)|(v[a-z0-9-]+)/
       - arm64v8:
           filters:
             branches:
               ignore: /.*/
             tags:
-              only: /(v[1-9]+(\.[0-9]+)*)|(v[a-z]+)/
+              only: /(v[1-9]+(\.[0-9]+)*(-[a-z0-9-]+)?)|(v[a-z0-9-]+)/
       - multiarch:
           requires:
             - amd64
@@ -144,4 +151,4 @@ workflows:
             branches:
               ignore: /.*/
             tags:
-              only: /(v[1-9]+(\.[0-9]+)*)|(v[a-z]+)/
+              only: /(v[1-9]+(\.[0-9]+)*(-[a-z0-9-]+)?)|(v[a-z0-9-]+)/

.circleci/run-tests.sh

@@ -3,7 +3,16 @@ set -e
 
 cd ../BTCPayServer.Tests
 docker-compose -v
-docker-compose down --v
-docker-compose pull
-docker-compose build
-docker-compose run -e "TEST_FILTERS=$1" tests
+docker-compose -f "docker-compose.altcoins.yml" down --v
+
+# For some reason, docker-compose pull fails time to time, so we try several times
+n=0
+until [ "$n" -ge 10 ]
+do
+   docker-compose -f "docker-compose.altcoins.yml" pull && break
+   n=$((n+1)) 
+   sleep 5
+done
+
+docker-compose -f "docker-compose.altcoins.yml" build
+docker-compose -f "docker-compose.altcoins.yml" run -e "TEST_FILTERS=$1" tests

.editorconfig

@@ -10,10 +10,15 @@ root = true
 insert_final_newline = true
 indent_style = space
 indent_size = 4
+charset = utf-8
+space_before_self_closing = true
 
-[project.json]
+[*.json]
 indent_size = 2
 
+[swagger*.json]
+indent_size = 4
+
 # C# files
 [*.cs]
 # New line preferences
@@ -66,7 +71,7 @@ dotnet_naming_symbols.private_internal_fields.applicable_kinds = field
 dotnet_naming_symbols.private_internal_fields.applicable_accessibilities = private, internal
 
 dotnet_naming_style.camel_case_underscore_style.required_prefix = _
-dotnet_naming_style.camel_case_underscore_style.capitalization = camel_case 
+dotnet_naming_style.camel_case_underscore_style.capitalization = camel_case
 
 # Code style defaults
 dotnet_sort_system_directives_first = true
@@ -120,8 +125,11 @@ csharp_space_between_method_declaration_name_and_open_parenthesis = false
 csharp_space_between_method_declaration_parameter_list_parentheses = false
 csharp_space_between_parentheses = false
 csharp_space_between_square_brackets = false
+csharp_style_prefer_null_check_over_type_check = true:warning
+csharp_prefer_simple_using_statement = true:warning
 
 # C++ Files
+
 [*.{cpp,h,in}]
 curly_bracket_next_line = true
 indent_brace_style = Allman
@@ -146,4 +154,4 @@ indent_size = 2
 [*.sh]
 end_of_line = lf
 [*.{cmd, bat}]
-end_of_line = crlf
+end_of_line = crlf

.github/ISSUE_TEMPLATE/bug_report.md

@@ -1,37 +0,0 @@
----
-name: Report a problem
-about: File a technical problem or report a bug
----
-
-**Describe the problem/bug**
-A clear and concise description of what the bug is.
-
-**Your environment**
-* Version of BTCPay Server:
-* Deployment method: 
-* Other relevant environment details:
-
-**Logs (if applicable)**
-Basic logs can be found in Server Settings > Logs.
-
-**Setup Parameters**
-If you're reporting a deployment issue run `. btcpay-setup.sh -i` and paste your the paremeters by obscuring private information.
-
-**To Reproduce**
-Steps to reproduce the behavior:
-1. Go to '...'
-2. Click on '....'
-3. Scroll down to '....'
-4. See error
-
-**Expected behavior**
-A clear and concise description of what you expected to happen.
-
-**Actual behavior**
-Tell us what happens instead
-
-**Screenshots/Links**
-If applicable, add screenshots or links to help explain your problem.
-
-**Additional context**
-Add any other context about the problem here.

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -0,0 +1,68 @@
+name: 🐛 Bug Report
+description: File a bug report
+title: "[Bug]: "
+labels: ["bug"]
+body:
+  - type: markdown
+    attributes:
+      value: |
+        Thanks for taking the time to fill out this bug report! Please provide as much information as you can. It helps us better understand the problem and fix it faster.
+  - type: textarea
+    id: version
+    attributes:
+      label: What is your BTCPay version?
+      description: You can see the version in the footer's bottom right corner
+      placeholder: I'm running BTCPay v1.X.X.X
+    validations:
+      required: true
+  - type: textarea
+    id: deployment
+    attributes:
+      label: How did you deploy BTCPay Server?
+      description: Docker, manual, third-party host? Read more on deployment methods [here](https://docs.btcpayserver.org/Deployment/)
+      placeholder: I'm running BTCPay Server on a...
+    validations:
+      required: true
+  - type: textarea
+    id: what-happened
+    attributes:
+      label: What happened?
+      description: A clear and concise description of what the bug is.
+      placeholder: Tell us what you see!
+    validations:
+      required: true
+  - type: textarea
+    id: reproduce
+    attributes:
+      label: How did you encounter this bug?
+      description: Step by step describe how did you encounter the bug?
+      placeholder: 1. I clicked X 2. Then I clicked Y 3. See error
+    validations:
+      required: true
+  - type: textarea
+    id: logoutput
+    attributes:
+      label: Relevant log output
+      description: Please copy and paste any relevant log output. This will be automatically formatted into code, so no need for backticks. Logs can be found in Server Settings > Logs. Here's how you can [troubleshoot an issue](https://docs.btcpayserver.org/Troubleshooting/)
+      render: shell
+  - type: textarea
+    id: browser
+    attributes:
+      label: What browser do you use?
+      description: Provide your browser and it's version. If you replicated issues on multiple browsers, let us know which ones.
+      placeholder: For example Safari 15.00, Chrome 10.0, Tor, Edge, etc
+    validations:
+      required: false
+  - type: textarea
+    id: additonal
+    attributes:
+      label: Additional information
+      description: Feel free to provide additional information. Screenshots are always helpful.
+  - type: checkboxes
+    id: terms
+    attributes:
+      label: Are you sure this is a bug report?
+      description: By submitting this report, you agree that this is not a support or a feature request. For general questions please read our [documentation](https://docs.btcpayserver.org). You can ask questions in [discussions](https://github.com/btcpayserver/btcpayserver/discussions) and [on our community chat](https://chat.btcpayserver.org)
+      options:
+        - label: I confirm this is a bug report
+          required: true

.github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1,11 @@
+blank_issues_enabled: true
+contact_links:
+  - name: 🚀 Discussions
+    url: https://github.com/btcpayserver/btcpayserver/discussions
+    about: Technical discussions, questions and feature requests
+  - name: 📝 Official Documentation
+    url: https://docs.btcpayserver.org
+    about: Check our documentation for answers to common questions
+  - name: 💬 Community Support Chat
+    url: https://chat.btcpayserver.org/
+    about: Ask general questions and get community support in real-time

.github/ISSUE_TEMPLATE/feature_request.md

@@ -1,20 +0,0 @@
----
-name: Feature request
-about: Ideas and feature requests
-
----
-
-**Is your feature request related to a problem? Please describe.**
-A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]
-
-**Describe the solution you'd like**
-A clear and concise description of what you want to happen.
-
-**Describe alternatives you've considered**
-A clear and concise description of any alternative solutions or features you've considered.
-
-**Provide examples**
-If applicable provide examples, wireframes, sketches or images to better explain your idea.
-
-**Additional context**
-Add any other context or screenshots about the feature request here.

.gitignore

@@ -288,9 +288,14 @@ __pycache__/
 *.xsd.cs
 /BTCPayServer/Build/dockerfiles
 
-# Bundling JS/CSS
-BTCPayServer/wwwroot/bundles/*
-!BTCPayServer/wwwroot/bundles/.gitignore
-
-.vscode
+.vscode/*
+!.vscode/launch.json
+!.vscode/tasks.json
+!.vscode/extensions.json
 BTCPayServer/testpwd
+.DS_Store
+Packed Plugins
+Plugins/packed
+
+BTCPayServer/wwwroot/swagger/v1/openapi.json
+BTCPayServer/appsettings.dev.json

.run/Pack Test Extension.run.xml

@@ -0,0 +1,21 @@
+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="Pack Test Plugin" type="DotNetProject" factoryName=".NET Project" singleton="false">
+    <option name="EXE_PATH" value="$PROJECT_DIR$/BTCPayServer.PluginPacker/bin/Debug/netcoreapp3.1/BTCPayServer.PluginPacker.dll" />
+    <option name="PROGRAM_PARAMETERS" value="../../../../BTCPayServer.Plugins.Test\bin\Debug\netcoreapp3.1 BTCPayServer.Plugins.Test &quot;../../../../Packed Plugins&quot;" />
+    <option name="WORKING_DIRECTORY" value="$PROJECT_DIR$/BTCPayServer.PluginPacker/bin/Debug/netcoreapp3.1" />
+    <option name="PASS_PARENT_ENVS" value="1" />
+    <option name="USE_EXTERNAL_CONSOLE" value="0" />
+    <option name="USE_MONO" value="0" />
+    <option name="RUNTIME_ARGUMENTS" value="" />
+    <option name="PROJECT_PATH" value="$PROJECT_DIR$/BTCPayServer.PluginPacker/BTCPayServer.PluginPacker.csproj" />
+    <option name="PROJECT_EXE_PATH_TRACKING" value="1" />
+    <option name="PROJECT_ARGUMENTS_TRACKING" value="1" />
+    <option name="PROJECT_WORKING_DIRECTORY_TRACKING" value="1" />
+    <option name="PROJECT_KIND" value="DotNetCore" />
+    <option name="PROJECT_TFM" value=".NETCoreApp,Version=v3.1" />
+    <method v="2">
+      <option name="Build" default="false" projectName="BTCPayServer.Plugins.Test" projectPath="C:\Git\btcpayserver\Plugins\BTCPayServer.Plugins.Test\BTCPayServer.Plugins.Test.csproj" />
+      <option name="Build" />
+    </method>
+  </configuration>
+</component>

.vscode/extensions.json

@@ -0,0 +1,3 @@
+{
+    "recommendations": ["ms-dotnettools.csharp"]
+}

.vscode/launch.json

@@ -0,0 +1,33 @@
+{
+    // Use IntelliSense to find out which attributes exist for C# debugging
+    // Use hover for the description of the existing attributes
+    // For further information visit https://github.com/OmniSharp/omnisharp-vscode/blob/master/debugger-launchjson.md
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "name": ".NET Core Launch (web)",
+            "type": "coreclr",
+            "request": "launch",
+            "preLaunchTask": "build",
+            // If you have changed target frameworks, make sure to update the program path.
+            "program": "${workspaceFolder}/BTCPayServer/bin/Debug/net6.0/BTCPayServer.dll",
+            "args": [],
+            "cwd": "${workspaceFolder}/BTCPayServer",
+            "stopAtEntry": false,
+            // Enable launching a web browser when ASP.NET Core starts. For more information: https://aka.ms/VSCode-CS-LaunchJson-WebBrowser
+            "serverReadyAction": {
+                "action": "openExternally",
+                "pattern": "\\bNow listening on:\\s+(https?://\\S+)"
+            },
+            "env": {
+                "ASPNETCORE_ENVIRONMENT": "Development"
+            },
+            "sourceFileMap": {
+                "/Views": "${workspaceFolder}/Views"
+            },
+            "logging": {
+                "moduleLoad": false
+            }
+        }
+    ]
+}

.vscode/tasks.json

@@ -0,0 +1,42 @@
+{
+    "version": "2.0.0",
+    "tasks": [
+        {
+            "label": "build",
+            "command": "dotnet",
+            "type": "process",
+            "args": [
+                "build",
+                "${workspaceFolder}/BTCPayServer/BTCPayServer.csproj",
+                "/property:GenerateFullPaths=true",
+                "/consoleloggerparameters:NoSummary"
+            ],
+            "problemMatcher": "$msCompile"
+        },
+        {
+            "label": "publish",
+            "command": "dotnet",
+            "type": "process",
+            "args": [
+                "publish",
+                "${workspaceFolder}/BTCPayServer/BTCPayServer.csproj",
+                "/property:GenerateFullPaths=true",
+                "/consoleloggerparameters:NoSummary"
+            ],
+            "problemMatcher": "$msCompile"
+        },
+        {
+            "label": "watch",
+            "command": "dotnet",
+            "type": "process",
+            "args": [
+                "watch",
+                "run",
+                "${workspaceFolder}/BTCPayServer/BTCPayServer.csproj",
+                "/property:GenerateFullPaths=true",
+                "/consoleloggerparameters:NoSummary"
+            ],
+            "problemMatcher": "$msCompile"
+        }
+    ]
+}

BTCPayServer.Abstractions/BTCPayServer.Abstractions.csproj

@@ -0,0 +1,43 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <Import Project="../Build/Version.csproj" Condition="Exists('../Build/Version.csproj')" />
+  <Import Project="../Build/Common.csproj" />
+
+  <PropertyGroup>
+    <Company>BTCPay Server</Company>
+    <Copyright>Copyright © BTCPay Server 2020</Copyright>
+    <Description>A library for BTCPay Server plugin development</Description>
+    <PackageIcon>icon.png</PackageIcon>
+    <PackageTags>btcpay,btcpayserver</PackageTags>
+    <PackageProjectUrl>https://github.com/btcpayserver/btcpayserver/tree/master/BTCPayServer.Abstractions</PackageProjectUrl>
+    <PackageLicenseExpression>MIT</PackageLicenseExpression>
+    <RepositoryUrl>https://github.com/btcpayserver/btcpayserver</RepositoryUrl>
+    <RepositoryType>git</RepositoryType>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)' == 'Release' ">
+    <PublishRepositoryUrl>true</PublishRepositoryUrl>
+    <EmbedUntrackedSources>true</EmbedUntrackedSources>
+    <DebugType>portable</DebugType>
+    <Optimize>true</Optimize>
+    <NoWarn>1591;1573;1572;1584;1570;3021</NoWarn>
+    <GenerateDocumentationFile>true</GenerateDocumentationFile>
+  </PropertyGroup>  
+  <ItemGroup Condition=" '$(Configuration)' == 'Release' ">
+    <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.0.0" PrivateAssets="All" />
+  </ItemGroup>
+  <ItemGroup>
+    <FrameworkReference Include="Microsoft.AspNetCore.App" />
+  </ItemGroup>
+  <ItemGroup>
+    <None Include="icon.png" Pack="true" PackagePath="\" />
+  </ItemGroup>
+  <ItemGroup>
+    <PackageReference Include="HtmlSanitizer" Version="5.0.372" />
+    <PackageReference Include="Microsoft.EntityFrameworkCore" Version="6.0.9" />
+    <PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite" Version="6.0.9" />
+    <PackageReference Include="Npgsql.EntityFrameworkCore.PostgreSQL" Version="6.0.7" />
+    <PackageReference Include="Pomelo.EntityFrameworkCore.MySql" Version="6.0.1" />
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\BTCPayServer.Client\BTCPayServer.Client.csproj" />
+  </ItemGroup>
+</Project>

BTCPayServer.Abstractions/CamelCaseSerializerSettings.cs

@@ -0,0 +1,18 @@
+using Newtonsoft.Json;
+
+namespace BTCPayServer.Abstractions
+{
+    public class CamelCaseSerializerSettings
+    {
+        static CamelCaseSerializerSettings()
+        {
+            Settings = new JsonSerializerSettings()
+            {
+                ContractResolver = new Newtonsoft.Json.Serialization.CamelCasePropertyNamesContractResolver()
+            };
+            Serializer = JsonSerializer.Create(Settings);
+        }
+        public static readonly JsonSerializerSettings Settings;
+        public static readonly JsonSerializer Serializer;
+    }
+}

BTCPayServer.Abstractions/Configuration/DataDirectories.cs

@@ -0,0 +1,20 @@
+using System.IO;
+
+namespace BTCPayServer.Configuration
+{
+    public class DataDirectories
+    {
+        public string DataDir { get; set; }
+        public string PluginDir { get; set; }
+        public string TempStorageDir { get; set; }
+        public string StorageDir { get; set; }
+        public string TempDir { get; set; }
+
+        public string ToDatadirFullPath(string path)
+        {
+            if (Path.IsPathRooted(path))
+                return path;
+            return Path.Combine(DataDir, path);
+        }
+    }
+}

BTCPayServer.Abstractions/Constants/AuthenticationSchemes.cs

@@ -1,4 +1,4 @@
-namespace BTCPayServer.Security
+namespace BTCPayServer.Abstractions.Constants
 {
     public class AuthenticationSchemes
     {

BTCPayServer.Abstractions/Constants/WellKnownTempData.cs

@@ -0,0 +1,7 @@
+namespace BTCPayServer.Abstractions.Constants;
+
+public class WellKnownTempData
+{
+    public const string SuccessMessage = nameof(SuccessMessage);
+    public const string ErrorMessage = nameof(ErrorMessage);
+}

BTCPayServer.Abstractions/Contracts/BaseDbContextFactory.cs

@@ -0,0 +1,111 @@
+using System;
+using BTCPayServer.Abstractions.Models;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Metadata;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Microsoft.Extensions.Options;
+using Npgsql.EntityFrameworkCore.PostgreSQL.Migrations;
+using Npgsql.EntityFrameworkCore.PostgreSQL.Migrations.Operations;
+
+namespace BTCPayServer.Abstractions.Contracts
+{
+    public abstract class BaseDbContextFactory<T> where T : DbContext
+    {
+        private readonly IOptions<DatabaseOptions> _options;
+        private readonly string _schemaPrefix;
+
+        public BaseDbContextFactory(IOptions<DatabaseOptions> options, string schemaPrefix)
+        {
+            _options = options;
+            _schemaPrefix = schemaPrefix;
+        }
+
+        public abstract T CreateContext();
+
+        class CustomNpgsqlMigrationsSqlGenerator : NpgsqlMigrationsSqlGenerator
+        {
+#pragma warning disable EF1001 // Internal EF Core API usage.
+            public CustomNpgsqlMigrationsSqlGenerator(MigrationsSqlGeneratorDependencies dependencies, Npgsql.EntityFrameworkCore.PostgreSQL.Infrastructure.Internal.INpgsqlSingletonOptions opts) : base(dependencies, opts)
+#pragma warning restore EF1001 // Internal EF Core API usage.
+            {
+            }
+
+            protected override void Generate(NpgsqlCreateDatabaseOperation operation, IModel model, MigrationCommandListBuilder builder)
+            {
+                builder
+                    .Append("CREATE DATABASE ")
+                    .Append(Dependencies.SqlGenerationHelper.DelimitIdentifier(operation.Name));
+
+                // POSTGRES gotcha: Indexed Text column (even if PK) are not used if we are not using C locale
+                builder
+                    .Append(" TEMPLATE ")
+                    .Append(Dependencies.SqlGenerationHelper.DelimitIdentifier("template0"));
+
+                builder
+                    .Append(" LC_CTYPE ")
+                    .Append(Dependencies.SqlGenerationHelper.DelimitIdentifier("C"));
+
+                builder
+                    .Append(" LC_COLLATE ")
+                    .Append(Dependencies.SqlGenerationHelper.DelimitIdentifier("C"));
+
+                builder
+                    .Append(" ENCODING ")
+                    .Append(Dependencies.SqlGenerationHelper.DelimitIdentifier("UTF8"));
+
+                if (operation.Tablespace != null)
+                {
+                    builder
+                        .Append(" TABLESPACE ")
+                        .Append(Dependencies.SqlGenerationHelper.DelimitIdentifier(operation.Tablespace));
+                }
+
+                builder.AppendLine(Dependencies.SqlGenerationHelper.StatementTerminator);
+
+                EndStatement(builder, suppressTransaction: true);
+            }
+        }
+
+        public void ConfigureBuilder(DbContextOptionsBuilder builder)
+        {
+            switch (_options.Value.DatabaseType)
+            {
+                case DatabaseType.Sqlite:
+                    builder.UseSqlite(_options.Value.ConnectionString, o =>
+                    {
+                        if (!string.IsNullOrEmpty(_schemaPrefix))
+                        {
+                            o.MigrationsHistoryTable(_schemaPrefix);
+                        }
+                    });
+                    break;
+                case DatabaseType.Postgres:
+                    builder
+                        .UseNpgsql(_options.Value.ConnectionString, o =>
+                        {
+                            o.EnableRetryOnFailure(10);
+                            if (!string.IsNullOrEmpty(_schemaPrefix))
+                            {
+                                o.MigrationsHistoryTable(_schemaPrefix);
+                            }
+                        })
+                        .ReplaceService<IMigrationsSqlGenerator, CustomNpgsqlMigrationsSqlGenerator>();
+                    break;
+                case DatabaseType.MySQL:
+                    builder.UseMySql(_options.Value.ConnectionString, ServerVersion.AutoDetect(_options.Value.ConnectionString), o =>
+                    {
+                        o.EnableRetryOnFailure(10);
+
+                        if (!string.IsNullOrEmpty(_schemaPrefix))
+                        {
+                            o.MigrationsHistoryTable(_schemaPrefix);
+                        }
+                    });
+                    break;
+                default:
+                    throw new ArgumentOutOfRangeException();
+            }
+        }
+
+    }
+}

BTCPayServer.Abstractions/Contracts/IBTCPayServerClientFactory.cs

@@ -0,0 +1,12 @@
+using System.Threading.Tasks;
+using BTCPayServer.Client;
+using Microsoft.AspNetCore.Http;
+
+namespace BTCPayServer.Abstractions.Contracts
+{
+    public interface IBTCPayServerClientFactory
+    {
+        Task<BTCPayServerClient> Create(string userId, params string[] storeIds);
+        Task<BTCPayServerClient> Create(string userId, string[] storeIds, HttpContext httpRequest);
+    }
+}

BTCPayServer.Abstractions/Contracts/IBTCPayServerPlugin.cs

@@ -0,0 +1,32 @@
+using System;
+using System.Text.Json.Serialization;
+using BTCPayServer.Abstractions.Converters;
+using Microsoft.AspNetCore.Builder;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace BTCPayServer.Abstractions.Contracts
+{
+    public interface IBTCPayServerPlugin
+    {
+        public string Identifier { get; }
+        string Name { get; }
+        [JsonConverter(typeof(VersionConverter))]
+        Version Version { get; }
+        string Description { get; }
+        bool SystemPlugin { get; set; }
+        PluginDependency[] Dependencies { get; }
+        void Execute(IApplicationBuilder applicationBuilder, IServiceProvider applicationBuilderApplicationServices);
+        void Execute(IServiceCollection applicationBuilder);
+
+        public class PluginDependency
+        {
+            public string Identifier { get; set; }
+            public string Condition { get; set; }
+            public override string ToString()
+            {
+                return $"{Identifier}: {Condition}";
+            }
+        }
+    }
+
+}

BTCPayServer.Abstractions/Contracts/IFileService.cs

@@ -0,0 +1,17 @@
+#nullable enable
+using System;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Http;
+
+namespace BTCPayServer.Abstractions.Contracts;
+
+public interface IFileService
+{
+    Task<bool> IsAvailable();
+    Task<IStoredFile> AddFile(IFormFile file, string userId);
+    Task<IStoredFile> AddFile(Uri file, string userId);
+    Task<string?> GetFileUrl(Uri baseUri, string fileId);
+    Task<string?> GetTemporaryFileUrl(Uri baseUri, string fileId, DateTimeOffset expiry,
+        bool isDownload);
+    Task RemoveFile(string fileId, string userId);
+}

BTCPayServer.Abstractions/Contracts/INotificationHandler.cs

@@ -0,0 +1,27 @@
+using System;
+
+namespace BTCPayServer.Abstractions.Contracts
+{
+    public abstract class BaseNotification
+    {
+        public abstract string Identifier { get; }
+        public abstract string NotificationType { get; }
+    }
+
+    public interface INotificationHandler
+    {
+        string NotificationType { get; }
+        Type NotificationBlobType { get; }
+        public (string identifier, string name)[] Meta { get; }
+        void FillViewModel(object notification, NotificationViewModel vm);
+    }
+
+    public class NotificationViewModel
+    {
+        public string Id { get; set; }
+        public DateTimeOffset Created { get; set; }
+        public string Body { get; set; }
+        public string ActionLink { get; set; }
+        public bool Seen { get; set; }
+    }
+}

BTCPayServer.Abstractions/Contracts/IPluginHookAction.cs

@@ -0,0 +1,10 @@
+using System.Threading.Tasks;
+
+namespace BTCPayServer.Abstractions.Contracts
+{
+    public interface IPluginHookAction
+    {
+        public string Hook { get; }
+        Task Execute(object args);
+    }
+}

BTCPayServer.Abstractions/Contracts/IPluginHookFilter.cs

@@ -0,0 +1,11 @@
+using System.Threading.Tasks;
+
+namespace BTCPayServer.Abstractions.Contracts
+{
+    public interface IPluginHookFilter
+    {
+        public string Hook { get; }
+
+        Task<object> Execute(object args);
+    }
+}

BTCPayServer.Abstractions/Contracts/IPluginHookService.cs

@@ -0,0 +1,10 @@
+using System.Threading.Tasks;
+
+namespace BTCPayServer.Abstractions.Contracts
+{
+    public interface IPluginHookService
+    {
+        Task ApplyAction(string hook, object args);
+        Task<object> ApplyFilter(string hook, object args);
+    }
+}

BTCPayServer.Abstractions/Contracts/IScopeProvider.cs

@@ -0,0 +1,7 @@
+#nullable enable
+namespace BTCPayServer.Abstractions.Contracts;
+
+public interface IScopeProvider
+{
+    string? GetCurrentStoreId();
+}

BTCPayServer.Abstractions/Contracts/ISettingsRepository.cs

@@ -0,0 +1,13 @@
+#nullable enable
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace BTCPayServer.Abstractions.Contracts
+{
+    public interface ISettingsRepository
+    {
+        Task<T?> GetSettingAsync<T>(string? name = null) where T : class;
+        Task UpdateSetting<T>(T obj, string? name = null) where T : class;
+        Task<T> WaitSettingsChanged<T>(CancellationToken cancellationToken = default) where T : class;
+    }
+}

BTCPayServer.Abstractions/Contracts/IStartupTask.cs

@@ -1,10 +1,7 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
 
-namespace BTCPayServer
+namespace BTCPayServer.Abstractions.Contracts
 {
     public interface IStartupTask
     {

BTCPayServer.Abstractions/Contracts/IStoreRepository.cs

@@ -0,0 +1,12 @@
+#nullable enable
+using System.Collections.Generic;
+using System.Threading.Tasks;
+
+namespace BTCPayServer.Abstractions.Contracts;
+
+public interface IStoreRepository
+{
+    Task<T?> GetSettingAsync<T>(string storeId, string name) where T : class;
+    Task<Dictionary<string, T?>> GetSettingsAsync<T>(string name) where T : class;
+    Task UpdateSetting<T>(string storeId, string name, T obj) where T : class;
+}

BTCPayServer.Abstractions/Contracts/IStoredFile.cs

@@ -0,0 +1,12 @@
+using System;
+
+namespace BTCPayServer.Abstractions.Contracts;
+
+public interface IStoredFile
+{
+    string Id { get; set; }
+    string FileName { get; set; }
+    string StorageFileName { get; set; }
+    DateTime Timestamp { get; set; }
+    string ApplicationUserId { get; set; }
+}

BTCPayServer.Abstractions/Contracts/ISwaggerProvider.cs

@@ -0,0 +1,9 @@
+using System.Threading.Tasks;
+using Newtonsoft.Json.Linq;
+
+namespace BTCPayServer.Abstractions.Contracts;
+
+public interface ISwaggerProvider
+{
+    Task<JObject> Fetch();
+}

BTCPayServer.Abstractions/Contracts/ISyncSummaryProvider.cs

@@ -0,0 +1,18 @@
+using System.Collections.Generic;
+
+namespace BTCPayServer.Abstractions.Contracts
+{
+    public interface ISyncSummaryProvider
+    {
+        bool AllAvailable();
+
+        string Partial { get; }
+        IEnumerable<ISyncStatus> GetStatuses();
+    }
+
+    public interface ISyncStatus
+    {
+        public string CryptoCode { get; set; }
+        public bool Available { get; }
+    }
+}

BTCPayServer.Abstractions/Contracts/IUIExtension.cs

@@ -0,0 +1,9 @@
+namespace BTCPayServer.Abstractions.Contracts
+{
+    public interface IUIExtension
+    {
+        string Partial { get; }
+
+        string Location { get; }
+    }
+}

BTCPayServer.Abstractions/Contracts/IUTXOLocker.cs

@@ -0,0 +1,13 @@
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using NBitcoin;
+
+namespace BTCPayServer.Payments.PayJoin;
+
+public interface IUTXOLocker
+{
+    Task<bool> TryLock(OutPoint outpoint);
+    Task<bool> TryUnlock(params OutPoint[] outPoints);
+    Task<bool> TryLockInputs(OutPoint[] outPoints);
+    Task<HashSet<OutPoint>> FindLocks(OutPoint[] outpoints);
+}

BTCPayServer.Abstractions/Converters/VersionConverter.cs

@@ -0,0 +1,19 @@
+using System;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+
+namespace BTCPayServer.Abstractions.Converters
+{
+    public class VersionConverter : JsonConverter<Version>
+    {
+        public override Version Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
+        {
+            return Version.Parse(reader.GetString());
+        }
+
+        public override void Write(Utf8JsonWriter writer, Version value, JsonSerializerOptions options)
+        {
+            writer.WriteStringValue(value.ToString());
+        }
+    }
+}

BTCPayServer.Abstractions/Custodians/Client/AssetQuoteResult.cs

@@ -0,0 +1,19 @@
+namespace BTCPayServer.Abstractions.Custodians.Client;
+
+public class AssetQuoteResult
+{
+    public string FromAsset { get; set; }
+    public string ToAsset { get; set; }
+    public decimal Bid { get; set; }
+    public decimal Ask { get; set; }
+
+    public AssetQuoteResult() { }
+
+    public AssetQuoteResult(string fromAsset, string toAsset, decimal bid, decimal ask)
+    {
+        FromAsset = fromAsset;
+        ToAsset = toAsset;
+        Bid = bid;
+        Ask = ask;
+    }
+}

BTCPayServer.Abstractions/Custodians/Client/Exception/AssetBalancesUnavailableException.cs

@@ -0,0 +1,8 @@
+namespace BTCPayServer.Abstractions.Custodians;
+
+public class AssetBalancesUnavailableException : CustodianApiException
+{
+    public AssetBalancesUnavailableException(System.Exception e) : base(500, "asset-balances-unavailable", $"Cannot fetch the asset balances: {e.Message}", e)
+    {
+    }
+}

BTCPayServer.Abstractions/Custodians/Client/Exception/AssetQuoteUnavailableException.cs

@@ -0,0 +1,13 @@
+using BTCPayServer.Client.Models;
+
+namespace BTCPayServer.Abstractions.Custodians;
+
+public class AssetQuoteUnavailableException : CustodianApiException
+{
+    public AssetPairData AssetPair { get; }
+
+    public AssetQuoteUnavailableException(AssetPairData assetPair) : base(400, "asset-price-unavailable", "Cannot find a quote for pair " + assetPair)
+    {
+        this.AssetPair = assetPair;
+    }
+}

BTCPayServer.Abstractions/Custodians/Client/Exception/BadConfigException.cs

@@ -0,0 +1,13 @@
+using System;
+
+namespace BTCPayServer.Abstractions.Custodians;
+
+public class BadConfigException : CustodianApiException
+{
+    public string[] BadConfigKeys { get; set; }
+
+    public BadConfigException(string[] badConfigKeys) : base(500, "bad-custodian-account-config", "Wrong config values: " + String.Join(", ", badConfigKeys))
+    {
+        this.BadConfigKeys = badConfigKeys;
+    }
+}

BTCPayServer.Abstractions/Custodians/Client/Exception/CannotWithdrawException.cs

@@ -0,0 +1,13 @@
+namespace BTCPayServer.Abstractions.Custodians;
+
+public class CannotWithdrawException : CustodianApiException
+
+{
+    public CannotWithdrawException(ICustodian custodian, string paymentMethod, string message) : base(403, "cannot-withdraw", message)
+    {
+    }
+
+    public CannotWithdrawException(ICustodian custodian, string paymentMethod, string targetAddress, CustodianApiException originalException) : base(403, "cannot-withdraw", $"{custodian.Name} cannot withdraw {paymentMethod} to '{targetAddress}': {originalException.Message}")
+    {
+    }
+}

BTCPayServer.Abstractions/Custodians/Client/Exception/CustodianApiException.cs

@@ -0,0 +1,18 @@
+using System;
+namespace BTCPayServer.Abstractions.Custodians;
+public class CustodianApiException : Exception
+{
+    public int HttpStatus { get; }
+    public string Code { get; }
+
+    public CustodianApiException(int httpStatus, string code, string message, System.Exception ex) : base(message, ex)
+    {
+        HttpStatus = httpStatus;
+        Code = code;
+    }
+    
+    public CustodianApiException(int httpStatus, string code, string message) : this(httpStatus, code, message, null)
+    {
+    }
+}
+

BTCPayServer.Abstractions/Custodians/Client/Exception/CustodianFeatureNotImplementedException.cs

@@ -0,0 +1,8 @@
+namespace BTCPayServer.Abstractions.Custodians;
+
+public class CustodianFeatureNotImplementedException : CustodianApiException
+{
+    public CustodianFeatureNotImplementedException(string message) : base(400, "not-implemented", message)
+    {
+    }
+}

BTCPayServer.Abstractions/Custodians/Client/Exception/DepositsUnavailableException.cs

@@ -0,0 +1,8 @@
+namespace BTCPayServer.Abstractions.Custodians;
+
+public class DepositsUnavailableException : CustodianApiException
+{
+    public DepositsUnavailableException(string message) : base(404, "deposits-unavailable", message)
+    {
+    }
+}

BTCPayServer.Abstractions/Custodians/Client/Exception/InsufficientFundsException.cs

@@ -0,0 +1,8 @@
+namespace BTCPayServer.Abstractions.Custodians;
+
+public class InsufficientFundsException : CustodianApiException
+{
+    public InsufficientFundsException(string message) : base(400, "insufficient-funds", message)
+    {
+    }
+}

BTCPayServer.Abstractions/Custodians/Client/Exception/InvalidWithdrawalTargetException.cs

@@ -0,0 +1,9 @@
+namespace BTCPayServer.Abstractions.Custodians;
+
+public class InvalidWithdrawalTargetException : CustodianApiException
+
+{
+    public InvalidWithdrawalTargetException(ICustodian custodian, string paymentMethod, string targetAddress, CustodianApiException originalException) : base(403, "invalid-withdrawal-target", $"{custodian.Name} cannot withdraw {paymentMethod} to '{targetAddress}': {originalException.Message}")
+    {
+    }
+}

BTCPayServer.Abstractions/Custodians/Client/Exception/PermissionDeniedCustodianApiException.cs

@@ -0,0 +1,9 @@
+namespace BTCPayServer.Abstractions.Custodians;
+
+public class PermissionDeniedCustodianApiException : CustodianApiException
+
+{
+    public PermissionDeniedCustodianApiException(ICustodian custodian) : base(403, "custodian-api-permission-denied", $"{custodian.Name}'s API reported that you don't have permission.")
+    {
+    }
+}

BTCPayServer.Abstractions/Custodians/Client/Exception/TradeNotFoundException.cs

@@ -0,0 +1,11 @@
+namespace BTCPayServer.Abstractions.Custodians;
+
+public class TradeNotFoundException : CustodianApiException
+{
+    private string tradeId { get; }
+
+    public TradeNotFoundException(string tradeId) : base(404, "trade-not-found", "Could not find trade ID " + tradeId)
+    {
+        this.tradeId = tradeId;
+    }
+}

BTCPayServer.Abstractions/Custodians/Client/Exception/WithdrawalNotFoundException.cs

@@ -0,0 +1,11 @@
+namespace BTCPayServer.Abstractions.Custodians;
+
+public class WithdrawalNotFoundException : CustodianApiException
+{
+    private string WithdrawalId { get; }
+
+    public WithdrawalNotFoundException(string withdrawalId) : base(404, "withdrawal-not-found", $"Could not find withdrawal ID {withdrawalId}.")
+    {
+        WithdrawalId = withdrawalId;
+    }
+}

BTCPayServer.Abstractions/Custodians/Client/Exception/WrongTradingPairException.cs

@@ -0,0 +1,9 @@
+namespace BTCPayServer.Abstractions.Custodians;
+
+public class WrongTradingPairException : CustodianApiException
+{
+    public const int HttpCode = 404;
+    public WrongTradingPairException(string fromAsset, string toAsset) : base(HttpCode, "wrong-trading-pair", $"Cannot find a trading pair for converting {fromAsset} into {toAsset}.")
+    {
+    }
+}

BTCPayServer.Abstractions/Custodians/Client/MarketTradeResult.cs

@@ -0,0 +1,29 @@
+using System.Collections.Generic;
+using BTCPayServer.Client.Models;
+
+namespace BTCPayServer.Abstractions.Custodians.Client;
+
+/**
+ * The result of a market trade. Used as a return type for custodians implementing ICanTrade
+ */
+public class MarketTradeResult
+{
+    public string FromAsset { get; }
+    public string ToAsset { get; }
+    /**
+     * The ledger entries that show the balances that were affected by the trade.
+     */
+    public List<LedgerEntryData> LedgerEntries { get; }
+    /**
+     * The unique ID of the trade that was executed.
+     */
+    public string TradeId { get; }
+
+    public MarketTradeResult(string fromAsset, string toAsset, List<LedgerEntryData> ledgerEntries, string tradeId)
+    {
+        this.FromAsset = fromAsset;
+        this.ToAsset = toAsset;
+        this.LedgerEntries = ledgerEntries;
+        this.TradeId = tradeId;
+    }
+}

BTCPayServer.Abstractions/Custodians/Client/WithdrawResult.cs

@@ -0,0 +1,29 @@
+using System;
+using System.Collections.Generic;
+using BTCPayServer.Client.Models;
+
+namespace BTCPayServer.Abstractions.Custodians.Client;
+
+public class WithdrawResult
+{
+    public string PaymentMethod { get; }
+    public string Asset { get; set; }
+    public List<LedgerEntryData> LedgerEntries { get; }
+    public string WithdrawalId { get; }
+    public WithdrawalResponseData.WithdrawalStatus Status { get; }
+    public DateTimeOffset CreatedTime { get; }
+    public string TargetAddress { get; }
+    public string TransactionId { get; }
+
+    public WithdrawResult(string paymentMethod, string asset, List<LedgerEntryData> ledgerEntries, string withdrawalId, WithdrawalResponseData.WithdrawalStatus status, DateTimeOffset createdTime, string targetAddress, string transactionId)
+    {
+        PaymentMethod = paymentMethod;
+        Asset = asset;
+        LedgerEntries = ledgerEntries;
+        WithdrawalId = withdrawalId;
+        CreatedTime = createdTime;
+        Status = status;
+        TargetAddress = targetAddress;
+        TransactionId = transactionId;
+    }
+}

BTCPayServer.Abstractions/Custodians/ICanDeposit.cs

@@ -0,0 +1,17 @@
+using System.Threading;
+using System.Threading.Tasks;
+using BTCPayServer.Client.Models;
+using Newtonsoft.Json.Linq;
+
+namespace BTCPayServer.Abstractions.Custodians;
+
+public interface ICanDeposit
+{
+    /**
+     * Get the address where we can deposit for the chosen payment method (crypto code + network).
+     * The result can be a string in different formats like a bitcoin address or even a LN invoice.
+     */
+    public Task<DepositAddressData> GetDepositAddressAsync(string paymentMethod, JObject config, CancellationToken cancellationToken);
+
+    public string[] GetDepositablePaymentMethods();
+}

BTCPayServer.Abstractions/Custodians/ICanTrade.cs

@@ -0,0 +1,31 @@
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+using BTCPayServer.Abstractions.Custodians.Client;
+using BTCPayServer.Client.Models;
+using Newtonsoft.Json.Linq;
+
+namespace BTCPayServer.Abstractions.Custodians;
+
+public interface ICanTrade
+{
+    /**
+     * A list of tradable asset pairs, or NULL if the custodian cannot trade/convert assets. if thr asset pair contains fiat, fiat is always put last. If both assets are a cyrptocode or both are fiat, the pair is written alphabetically. Always in uppercase. Example: ["BTC/EUR","BTC/USD", "EUR/USD", "BTC/ETH",...]
+     */
+    public List<AssetPairData> GetTradableAssetPairs();
+
+    /**
+     * Execute a market order right now.
+     */
+    public Task<MarketTradeResult> TradeMarketAsync(string fromAsset, string toAsset, decimal qty, JObject config, CancellationToken cancellationToken);
+
+    /**
+     * Get the details about a previous market trade.
+     */
+    public Task<MarketTradeResult> GetTradeInfoAsync(string tradeId, JObject config, CancellationToken cancellationToken);
+
+    public Task<AssetQuoteResult> GetQuoteForAssetAsync(string fromAsset, string toAsset, JObject config, CancellationToken cancellationToken);
+}
+
+
+

BTCPayServer.Abstractions/Custodians/ICanWithdraw.cs

@@ -0,0 +1,15 @@
+using System.Threading;
+using System.Threading.Tasks;
+using BTCPayServer.Abstractions.Custodians.Client;
+using Newtonsoft.Json.Linq;
+
+namespace BTCPayServer.Abstractions.Custodians;
+
+public interface ICanWithdraw
+{
+    public Task<WithdrawResult> WithdrawAsync(string paymentMethod, decimal amount, JObject config, CancellationToken cancellationToken);
+
+    public Task<WithdrawResult> GetWithdrawalInfoAsync(string paymentMethod, string withdrawalId, JObject config, CancellationToken cancellationToken);
+
+    public string[] GetWithdrawablePaymentMethods();
+}

BTCPayServer.Abstractions/Custodians/ICustodian.cs

@@ -0,0 +1,26 @@
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+using BTCPayServer.Client.Models;
+using Newtonsoft.Json.Linq;
+
+namespace BTCPayServer.Abstractions.Custodians;
+
+public interface ICustodian
+{
+    /**
+     * Get the unique code that identifies this custodian.
+     */
+    string Code { get; }
+
+    string Name { get; }
+
+    /**
+     * Get a list of assets and their qty in custody.
+     */
+    Task<Dictionary<string, decimal>> GetAssetBalancesAsync(JObject config, CancellationToken cancellationToken);
+
+    public Task<Form.Form> GetConfigForm(JObject config, string locale,
+        CancellationToken cancellationToken = default);
+
+}

BTCPayServer.Abstractions/Extensions/CustodianExtensions.cs

@@ -0,0 +1,14 @@
+#nullable enable
+using System.Collections.Generic;
+using System.Linq;
+using BTCPayServer.Abstractions.Custodians;
+
+namespace BTCPayServer.Abstractions.Extensions;
+
+public static class CustodianExtensions
+{
+    public static ICustodian? GetCustodianByCode(this IEnumerable<ICustodian> custodians, string code)
+    {
+        return custodians.FirstOrDefault(custodian => custodian.Code == code);
+    }
+}

BTCPayServer.Abstractions/Extensions/GreenfieldExtensions.cs

@@ -0,0 +1,43 @@
+using System.Collections.Generic;
+using BTCPayServer.Client.Models;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.AspNetCore.Mvc.ModelBinding;
+
+namespace BTCPayServer.Abstractions.Extensions;
+
+public static class GreenfieldExtensions
+{
+    public static IActionResult CreateValidationError(this ControllerBase controller, ModelStateDictionary modelState)
+    {
+        return controller.UnprocessableEntity(modelState.ToGreenfieldValidationError());
+    }
+
+    public static List<GreenfieldValidationError> ToGreenfieldValidationError(this ModelStateDictionary modelState)
+    {
+        List<GreenfieldValidationError> errors = new List<GreenfieldValidationError>();
+        foreach (var error in modelState)
+        {
+            foreach (var errorMessage in error.Value.Errors)
+            {
+                errors.Add(new GreenfieldValidationError(error.Key, errorMessage.ErrorMessage));
+            }
+        }
+
+        return errors;
+    }
+
+    public static IActionResult CreateAPIError(this ControllerBase controller, string errorCode, string errorMessage)
+    {
+        return controller.BadRequest(new GreenfieldAPIError(errorCode, errorMessage));
+    }
+
+    public static IActionResult CreateAPIError(this ControllerBase controller, int httpCode, string errorCode, string errorMessage)
+    {
+        return controller.StatusCode(httpCode, new GreenfieldAPIError(errorCode, errorMessage));
+    }
+
+    public static IActionResult CreateAPIPermissionError(this ControllerBase controller, string missingPermission, string message = null)
+    {
+        return controller.StatusCode(403, new GreenfieldPermissionAPIError(missingPermission, message));
+    }
+}

BTCPayServer.Abstractions/Extensions/HttpRequestExtensions.cs

@@ -0,0 +1,120 @@
+using System;
+using Microsoft.AspNetCore.Http;
+
+namespace BTCPayServer.Abstractions.Extensions;
+
+public static class HttpRequestExtensions
+{
+    public static bool IsOnion(this HttpRequest request)
+    {
+        if (request?.Host.Host == null)
+            return false;
+        return request.Host.Host.EndsWith(".onion", StringComparison.OrdinalIgnoreCase);
+    }
+
+    public static string GetAbsoluteRoot(this HttpRequest request)
+    {
+        return string.Concat(
+            request.Scheme,
+            "://",
+            request.Host.ToUriComponent(),
+            request.PathBase.ToUriComponent());
+    }
+
+    public static Uri GetAbsoluteRootUri(this HttpRequest request)
+    {
+        return new Uri(request.GetAbsoluteRoot());
+    }
+
+    public static string GetCurrentUrl(this HttpRequest request)
+    {
+        return string.Concat(
+            request.Scheme,
+            "://",
+            request.Host.ToUriComponent(),
+            request.PathBase.ToUriComponent(),
+            request.Path.ToUriComponent());
+    }
+
+    public static string GetCurrentPath(this HttpRequest request)
+    {
+        return string.Concat(
+            request.PathBase.ToUriComponent(),
+            request.Path.ToUriComponent());
+    }
+
+    public static string GetCurrentPathWithQueryString(this HttpRequest request)
+    {
+        return request.PathBase + request.Path + request.QueryString;
+    }
+
+    /// <summary>
+    /// If 'toto' and RootPath is 'rootpath' returns '/rootpath/toto'
+    /// If 'toto' and RootPath is empty returns '/toto'
+    /// </summary>
+    /// <param name="request"></param>
+    /// <param name="path"></param>
+    /// <returns></returns>
+    public static string GetRelativePath(this HttpRequest request, string path)
+    {
+        if (path.Length > 0 && path[0] != '/')
+            path = $"/{path}";
+        return string.Concat(
+            request.PathBase.ToUriComponent(),
+            path);
+    }
+
+    /// <summary>
+    /// If 'https://example.com/toto' returns 'https://example.com/toto'
+    /// If 'toto' and RootPath is 'rootpath' returns '/rootpath/toto'
+    /// If 'toto' and RootPath is empty returns '/toto'
+    /// </summary>
+    /// <param name="request"></param>
+    /// <param name="path"></param>
+    /// <returns></returns>
+    public static string GetRelativePathOrAbsolute(this HttpRequest request, string path)
+    {
+        if (!Uri.TryCreate(path, UriKind.RelativeOrAbsolute, out var uri) ||
+            uri.IsAbsoluteUri)
+            return path;
+
+        if (path.Length > 0 && path[0] != '/')
+            path = $"/{path}";
+        return string.Concat(
+            request.PathBase.ToUriComponent(),
+            path);
+    }
+
+    public static string GetAbsoluteUri(this HttpRequest request, string redirectUrl)
+    {
+        bool isRelative =
+            (redirectUrl.Length > 0 && redirectUrl[0] == '/')
+            || !new Uri(redirectUrl, UriKind.RelativeOrAbsolute).IsAbsoluteUri;
+        return isRelative ? request.GetAbsoluteRoot() + redirectUrl : redirectUrl;
+    }
+
+    /// <summary>
+    /// Will return an absolute URL. 
+    /// If `relativeOrAsbolute` is absolute, returns it.
+    /// If `relativeOrAsbolute` is relative, send absolute url based on the HOST of this request (without PathBase)
+    /// </summary>
+    /// <param name="request"></param>
+    /// <param name="relativeOrAbsolte"></param>
+    /// <returns></returns>
+    public static Uri GetAbsoluteUriNoPathBase(this HttpRequest request, Uri relativeOrAbsolute = null)
+    {
+        if (relativeOrAbsolute == null)
+        {
+            return new Uri(string.Concat(
+                request.Scheme,
+                "://",
+                request.Host.ToUriComponent()), UriKind.Absolute);
+        }
+        if (relativeOrAbsolute.IsAbsoluteUri)
+            return relativeOrAbsolute;
+        return new Uri(string.Concat(
+            request.Scheme,
+            "://",
+            request.Host.ToUriComponent()) + relativeOrAbsolute.ToString().WithStartingSlash(), UriKind.Absolute);
+    }
+}

BTCPayServer.Abstractions/Extensions/ITempDataDictionaryExtensions.cs

@@ -0,0 +1,59 @@
+using System.Text.Json;
+using BTCPayServer.Abstractions.Constants;
+using BTCPayServer.Abstractions.Models;
+using Microsoft.AspNetCore.Mvc.ViewFeatures;
+using Newtonsoft.Json.Linq;
+
+namespace BTCPayServer.Abstractions.Extensions;
+
+public static class SetStatusMessageModelExtensions
+{
+    public static void SetStatusMessageModel(this ITempDataDictionary tempData, StatusMessageModel statusMessage)
+    {
+        if (statusMessage == null)
+        {
+            tempData.Remove("StatusMessageModel");
+            return;
+        }
+
+        tempData["StatusMessageModel"] = JsonSerializer.Serialize(statusMessage, new JsonSerializerOptions());
+    }
+
+    public static StatusMessageModel GetStatusMessageModel(this ITempDataDictionary tempData)
+    {
+        tempData.TryGetValue(WellKnownTempData.SuccessMessage, out var successMessage);
+        tempData.TryGetValue(WellKnownTempData.ErrorMessage, out var errorMessage);
+        tempData.TryGetValue("StatusMessageModel", out var model);
+        if (successMessage != null || errorMessage != null)
+        {
+            var parsedModel = new StatusMessageModel();
+            parsedModel.Message = (string)successMessage ?? (string)errorMessage;
+            if (successMessage != null)
+            {
+                parsedModel.Severity = StatusMessageModel.StatusSeverity.Success;
+            }
+            else
+            {
+                parsedModel.Severity = StatusMessageModel.StatusSeverity.Error;
+            }
+            return parsedModel;
+        }
+        else if (model != null && model is string str)
+        {
+            return JObject.Parse(str).ToObject<StatusMessageModel>();
+        }
+        return null;
+    }
+
+    public static bool HasStatusMessage(this ITempDataDictionary tempData)
+    {
+        return (tempData.Peek(WellKnownTempData.SuccessMessage) ??
+                tempData.Peek(WellKnownTempData.ErrorMessage) ??
+                tempData.Peek("StatusMessageModel")) != null;
+    }
+
+    public static bool HasErrorMessage(this ITempDataDictionary tempData)
+    {
+        return GetStatusMessageModel(tempData)?.Severity == StatusMessageModel.StatusSeverity.Error;
+    }
+}

BTCPayServer.Abstractions/Extensions/ServiceCollectionExtensions.cs

@@ -0,0 +1,12 @@
+using BTCPayServer.Abstractions.Contracts;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace BTCPayServer.Abstractions.Extensions
+{
+    public static class ServiceCollectionExtensions
+    {
+        public static IServiceCollection AddStartupTask<T>(this IServiceCollection services)
+            where T : class, IStartupTask
+            => services.AddTransient<IStartupTask, T>();
+    }
+}

BTCPayServer.Abstractions/Extensions/StringExtensions.cs

@@ -0,0 +1,43 @@
+using System;
+using System.IO;
+using System.Linq;
+
+namespace BTCPayServer.Abstractions.Extensions;
+
+public static class StringExtensions
+{
+    public static bool IsValidFileName(this string fileName)
+    {
+        return !fileName.ToCharArray().Any(c => Path.GetInvalidFileNameChars().Contains(c)
+                                                || c == Path.AltDirectorySeparatorChar
+                                                || c == Path.DirectorySeparatorChar
+                                                || c == Path.PathSeparator
+                                                || c == '\\');
+    }
+
+    public static string Truncate(this string value, int maxLength)
+    {
+        if (string.IsNullOrEmpty(value))
+            return value;
+        return value.Length <= maxLength ? value : value.Substring(0, maxLength);
+    }
+
+    public static string WithTrailingSlash(this string str)
+    {
+        if (str.EndsWith("/", StringComparison.InvariantCulture))
+            return str;
+        return str + "/";
+    }
+    public static string WithStartingSlash(this string str)
+    {
+        if (str.StartsWith("/", StringComparison.InvariantCulture))
+            return str;
+        return $"/{str}";
+    }
+    public static string WithoutEndingSlash(this string str)
+    {
+        if (str.EndsWith("/", StringComparison.InvariantCulture))
+            return str.Substring(0, str.Length - 1);
+        return str;
+    }
+}

BTCPayServer.Abstractions/Extensions/ViewsRazor.cs

@@ -0,0 +1,139 @@
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+using System.Linq;
+using Microsoft.AspNetCore.Html;
+using Microsoft.AspNetCore.Mvc.ViewFeatures;
+
+namespace BTCPayServer.Abstractions.Extensions
+{
+    public static class ViewsRazor
+    {
+        private const string ACTIVE_CATEGORY_KEY = "ActiveCategory";
+        private const string ACTIVE_PAGE_KEY = "ActivePage";
+        private const string ACTIVE_ID_KEY = "ActiveId";
+        private const string ActivePageClass = "active";
+
+        public enum DateDisplayFormat
+        {
+            Localized,
+            Relative
+        }
+
+        public static void SetActivePage<T>(this ViewDataDictionary viewData, T activePage, string title = null, string activeId = null)
+            where T : IConvertible
+        {
+            SetActivePage(viewData, activePage.ToString(), activePage.GetType().ToString(), title, activeId);
+        }
+
+        public static void SetActivePage(this ViewDataDictionary viewData, string activePage, string category, string title = null, string activeId = null)
+        {
+            // Page Title
+            viewData["Title"] = title ?? activePage;
+            // Navigation
+            viewData[ACTIVE_PAGE_KEY] = activePage;
+            viewData[ACTIVE_ID_KEY] = activeId;
+            SetActiveCategory(viewData, category);
+        }
+
+        public static void SetActiveCategory<T>(this ViewDataDictionary viewData, T activeCategory)
+        {
+            SetActiveCategory(viewData, activeCategory.ToString());
+        }
+
+        public static void SetActiveCategory(this ViewDataDictionary viewData, string activeCategory)
+        {
+            viewData[ACTIVE_CATEGORY_KEY] = activeCategory;
+        }
+
+        public static string IsActiveCategory<T>(this ViewDataDictionary viewData, T category, object id = null)
+        {
+            return IsActiveCategory(viewData, category.ToString(), id);
+        }
+
+        public static string IsActiveCategory(this ViewDataDictionary viewData, string category, object id = null)
+        {
+            if (!viewData.ContainsKey(ACTIVE_CATEGORY_KEY))
+            {
+                return null;
+            }
+            var activeId = viewData[ACTIVE_ID_KEY];
+            var activeCategory = viewData[ACTIVE_CATEGORY_KEY]?.ToString();
+            var categoryMatch = category.Equals(activeCategory, StringComparison.InvariantCultureIgnoreCase);
+            var idMatch = id == null || activeId == null || id.Equals(activeId);
+            return categoryMatch && idMatch ? ActivePageClass : null;
+        }
+
+        public static string IsActivePage<T>(this ViewDataDictionary viewData, T page, object id = null)
+            where T : IConvertible
+        {
+            return IsActivePage(viewData, page.ToString(), page.GetType().ToString(), id);
+        }
+
+        public static string IsActivePage<T>(this ViewDataDictionary viewData, IEnumerable<T> pages, object id = null)
+            where T : IConvertible
+        {
+            return pages.Any(page => IsActivePage(viewData, page.ToString(), page.GetType().ToString(), id) == ActivePageClass)
+                ? ActivePageClass
+                : null;
+        }
+
+        public static string IsActivePage(this ViewDataDictionary viewData, string page, string category, object id = null)
+        {
+            if (!viewData.ContainsKey(ACTIVE_PAGE_KEY))
+            {
+                return null;
+            }
+            var activeId = viewData[ACTIVE_ID_KEY];
+            var activePage = viewData[ACTIVE_PAGE_KEY]?.ToString();
+            var activeCategory = viewData[ACTIVE_CATEGORY_KEY]?.ToString();
+            var categoryAndPageMatch = (category == null || activeCategory.Equals(category, StringComparison.InvariantCultureIgnoreCase)) && page.Equals(activePage, StringComparison.InvariantCultureIgnoreCase);
+            var idMatch = id == null || activeId == null || id.Equals(activeId);
+            return categoryAndPageMatch && idMatch ? ActivePageClass : null;
+        }
+
+        public static HtmlString ToBrowserDate(this DateTimeOffset date, DateDisplayFormat format = DateDisplayFormat.Localized)
+        {
+            var relative = date.ToTimeAgo();
+            var initial = format.ToString().ToLower();
+            var dateTime = date.ToString("o", CultureInfo.InvariantCulture);
+            var displayDate = format == DateDisplayFormat.Relative ? relative : date.ToString("g", CultureInfo.InvariantCulture);
+            return new HtmlString($"<time datetime=\"{dateTime}\" data-relative=\"{relative}\" data-initial=\"{initial}\">{displayDate}</time>");
+        }
+
+        public static HtmlString ToBrowserDate(this DateTime date, DateDisplayFormat format = DateDisplayFormat.Localized)
+        {
+            var relative = date.ToTimeAgo();
+            var initial = format.ToString().ToLower();
+            var dateTime = date.ToString("o", CultureInfo.InvariantCulture);
+            var displayDate = format == DateDisplayFormat.Relative ? relative : date.ToString("g", CultureInfo.InvariantCulture);
+            return new HtmlString($"<time datetime=\"{dateTime}\" data-relative=\"{relative}\" data-initial=\"{initial}\">{displayDate}</time>");
+        }
+
+        public static string ToTimeAgo(this DateTimeOffset date) => (DateTimeOffset.UtcNow - date).ToTimeAgo();
+
+        public static string ToTimeAgo(this DateTime date) => (DateTimeOffset.UtcNow - date).ToTimeAgo();
+
+        public static string ToTimeAgo(this TimeSpan diff) => diff.TotalSeconds > 0 ? $"{diff.TimeString()} ago" : $"in {diff.Negate().TimeString()}";
+
+        public static string TimeString(this TimeSpan timeSpan)
+        {
+            if (timeSpan.TotalMinutes < 1)
+            {
+                return $"{(int)timeSpan.TotalSeconds} second{Plural((int)timeSpan.TotalSeconds)}";
+            }
+            if (timeSpan.TotalHours < 1)
+            {
+                return $"{(int)timeSpan.TotalMinutes} minute{Plural((int)timeSpan.TotalMinutes)}";
+            }
+            return timeSpan.Days < 1
+                ? $"{(int)timeSpan.TotalHours} hour{Plural((int)timeSpan.TotalHours)}"
+                : $"{(int)timeSpan.TotalDays} day{Plural((int)timeSpan.TotalDays)}";
+        }
+
+        private static string Plural(int value)
+        {
+            return value == 1 ? string.Empty : "s";
+        }
+    }
+}

BTCPayServer.Abstractions/Form/AlertMessage.cs

@@ -0,0 +1,37 @@
+using Newtonsoft.Json;
+using Newtonsoft.Json.Converters;
+
+namespace BTCPayServer.Abstractions.Form;
+
+public class AlertMessage
+{
+    // Corresponds to the Bootstrap CSS "alert alert-xxx" messages:
+    // Success = green
+    // Warning = orange
+    // Danger = red
+    // Info = blue
+    public enum AlertMessageType
+    {
+        Success,
+        Warning,
+        Danger,
+        Info
+    }
+
+    [JsonConverter(typeof(StringEnumConverter))]
+    public AlertMessageType Type;
+
+    // The translated message to be shown to the user
+    public string Message;
+
+    public AlertMessage()
+    {
+
+    }
+
+    public AlertMessage(AlertMessageType type, string message)
+    {
+        this.Type = type;
+        this.Message = message;
+    }
+}

BTCPayServer.Abstractions/Form/Field.cs

@@ -0,0 +1,64 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Linq;
+using Microsoft.AspNetCore.Mvc.ModelBinding;
+using Newtonsoft.Json;
+using Newtonsoft.Json.Linq;
+
+namespace BTCPayServer.Abstractions.Form;
+
+public class Field
+{
+    public static Field Create(string label, string name, string value, bool required, string helpText, string type = "text")
+    {
+        return new Field()
+        {
+            Label = label,
+            Name = name,
+            Value = value,
+            OriginalValue = value,
+            Required = required,
+            HelpText = helpText,
+            Type = type
+        };
+    }
+    // The name of the HTML5 node. Should be used as the key for the posted data.
+    public string Name;
+
+    public bool Hidden;
+
+    // HTML5 compatible type string like "text", "textarea", "email", "password", etc. Each type is a class and may contain more fields (i.e. "select" would have options).
+    public string Type;
+
+    public static Field CreateFieldset()
+    {
+        return new Field() { Type = "fieldset" };
+    }
+
+    // The value field is what is currently in the DB or what the user entered, but possibly not saved yet due to validation errors.
+    // If this is the first the user sees the form, then value and original value are the same. Value changes as the user starts interacting with the form.
+    public string Value;
+
+    public bool Required;
+
+    // The translated label of the field.
+    public string Label;
+
+    // The original value is the value that is currently saved in the backend. A "reset" button can be used to revert back to this. Should only be set from the constructor.
+    public string OriginalValue;
+
+    // A useful note shown below the field or via a tooltip / info icon. Should be translated for the user.
+    public string HelpText;
+
+    [JsonExtensionData] public IDictionary<string, JToken> AdditionalData { get; set; }
+    public List<Field> Fields { get; set; } = new();
+
+    // The field is considered "valid" if there are no validation errors
+    public List<string> ValidationErrors = new List<string>();
+
+    public virtual bool IsValid()
+    {
+        return ValidationErrors.Count == 0 && Fields.All(field => field.IsValid());
+    }
+}

BTCPayServer.Abstractions/Form/Form.cs

@@ -0,0 +1,157 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Mvc.ModelBinding;
+using Newtonsoft.Json.Linq;
+
+namespace BTCPayServer.Abstractions.Form;
+
+public class Form
+{
+#nullable enable
+    public static Form Parse(string str)
+    {
+        ArgumentNullException.ThrowIfNull(str);
+        return JObject.Parse(str).ToObject<Form>(CamelCaseSerializerSettings.Serializer) ?? throw new InvalidOperationException("Impossible to deserialize Form");
+    }
+    public override string ToString()
+    {
+        return JObject.FromObject(this, CamelCaseSerializerSettings.Serializer).ToString(Newtonsoft.Json.Formatting.Indented);
+    }
+#nullable restore
+    // Messages to be shown at the top of the form indicating user feedback like "Saved successfully" or "Please change X because of Y." or a warning, etc...
+    public List<AlertMessage> TopMessages { get; set; } = new();
+
+    // Groups of fields in the form
+    public List<Field> Fields { get; set; } = new();
+
+    // Are all the fields valid in the form?
+    public bool IsValid()
+    {
+        return Fields.Select(f => f.IsValid()).All(o => o);
+    }
+
+    public Field GetFieldByName(string name)
+    {
+        return GetFieldByName(name, Fields, null);
+    }
+
+    private static Field GetFieldByName(string name, List<Field> fields, string prefix)
+    {
+        prefix ??= string.Empty;
+        foreach (var field in fields)
+        {
+            var currentPrefix = prefix;
+            if (!string.IsNullOrEmpty(field.Name))
+            {
+
+                currentPrefix = $"{prefix}{field.Name}";
+                if (currentPrefix.Equals(name, StringComparison.InvariantCultureIgnoreCase))
+                {
+                    return field;
+                }
+
+                currentPrefix += "_";
+            }
+
+            var subFieldResult = GetFieldByName(name, field.Fields, currentPrefix);
+            if (subFieldResult is not null)
+            {
+                return subFieldResult;
+            }
+
+        }
+        return null;
+    }
+
+    public List<string> GetAllNames()
+    {
+        return GetAllNames(Fields);
+    }
+
+    private static List<string> GetAllNames(List<Field> fields)
+    {
+        var names = new List<string>();
+
+        foreach (var field in fields)
+        {
+            string prefix = string.Empty;
+            if (!string.IsNullOrEmpty(field.Name))
+            {
+                names.Add(field.Name);
+                prefix = $"{field.Name}_";
+            }
+
+            if (field.Fields.Any())
+            {
+                names.AddRange(GetAllNames(field.Fields).Select(s => $"{prefix}{s}"));
+            }
+        }
+
+        return names;
+    }
+
+    public void ApplyValuesFromOtherForm(Form form)
+    {
+        foreach (var fieldset in Fields)
+        {
+            foreach (var field in fieldset.Fields)
+            {
+                field.Value = form
+                    .GetFieldByName(
+                        $"{(string.IsNullOrEmpty(fieldset.Name) ? string.Empty : fieldset.Name + "_")}{field.Name}")
+                    ?.Value;
+            }
+        }
+    }
+
+    public void ApplyValuesFromForm(IFormCollection form)
+    {
+        var names = GetAllNames();
+        foreach (var name in names)
+        {
+            var field = GetFieldByName(name);
+            if (field is null || !form.TryGetValue(name, out var val))
+            {
+                continue;
+            }
+
+            field.Value = val;
+        }
+    }
+
+    public Dictionary<string, object> GetValues()
+    {
+        return GetValues(Fields);
+    }
+
+    private static Dictionary<string, object> GetValues(List<Field> fields)
+    {
+        var result = new Dictionary<string, object>();
+        foreach (Field field in fields)
+        {
+            var name = field.Name ?? string.Empty;
+            if (field.Fields.Any())
+            {
+                var values = GetValues(fields);
+                values.Remove(string.Empty, out var keylessValue);
+
+                result.TryAdd(name, values);
+
+                if (keylessValue is not Dictionary<string, object> dict)
+                    continue;
+                foreach (KeyValuePair<string, object> keyValuePair in dict)
+                {
+                    result.TryAdd(keyValuePair.Key, keyValuePair.Value);
+                }
+            }
+            else
+            {
+                result.TryAdd(name, field.Value);
+            }
+        }
+
+        return result;
+    }
+}

BTCPayServer.Abstractions/Models/BaseBTCPayServerPlugin.cs

@@ -0,0 +1,69 @@
+using System;
+using System.Reflection;
+using BTCPayServer.Abstractions.Contracts;
+using Microsoft.AspNetCore.Builder;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace BTCPayServer.Abstractions.Models
+{
+    public abstract class BaseBTCPayServerPlugin : IBTCPayServerPlugin
+    {
+        public virtual string Identifier
+        {
+            get
+            {
+                return GetType().GetTypeInfo().Assembly.GetName().Name;
+            }
+        }
+        public virtual string Name
+        {
+            get
+            {
+                return GetType().GetTypeInfo().Assembly
+                        .GetCustomAttribute<AssemblyProductAttribute>()?
+                        .Product ?? "???";
+            }
+        }
+
+        public virtual Version Version
+        {
+            get
+            {
+                return GetVersion(GetType().GetTypeInfo().Assembly
+                        .GetCustomAttribute<AssemblyInformationalVersionAttribute>()?
+                        .InformationalVersion) ??
+                        Assembly.GetAssembly(GetType())?.GetName()?.Version ??
+                        new Version(1, 0, 0, 0);
+            }
+        }
+
+        private static Version GetVersion(string informationalVersion)
+        {
+            if (informationalVersion is null)
+                return null;
+            Version.TryParse(informationalVersion, out var r);
+            return r;
+        }
+
+        public virtual string Description
+        {
+            get
+            {
+                return GetType().GetTypeInfo().Assembly
+                        .GetCustomAttribute<AssemblyDescriptionAttribute>()?
+                        .Description ?? string.Empty;
+            }
+        }
+        public bool SystemPlugin { get; set; }
+        public virtual IBTCPayServerPlugin.PluginDependency[] Dependencies { get; } = Array.Empty<IBTCPayServerPlugin.PluginDependency>();
+
+        public virtual void Execute(IApplicationBuilder applicationBuilder,
+            IServiceProvider applicationBuilderApplicationServices)
+        {
+        }
+
+        public virtual void Execute(IServiceCollection applicationBuilder)
+        {
+        }
+    }
+}

BTCPayServer.Abstractions/Models/ConfirmModel.cs

@@ -0,0 +1,34 @@
+using System;
+
+namespace BTCPayServer.Abstractions.Models
+{
+    public class ConfirmModel
+    {
+        private const string ButtonClassDefault = "btn-danger";
+
+        public ConfirmModel() { }
+
+        public ConfirmModel(string title, string desc, string action = null, string buttonClass = ButtonClassDefault, string actionName = null, string controllerName = null)
+        {
+            Title = title;
+            Description = desc;
+            Action = action;
+            ActionName = actionName;
+            ControllerName = controllerName;
+            ButtonClass = buttonClass;
+
+            if (Description.Contains("<strong>", StringComparison.InvariantCultureIgnoreCase))
+            {
+                DescriptionHtml = true;
+            }
+        }
+
+        public string Title { get; set; }
+        public string Description { get; set; }
+        public bool DescriptionHtml { get; set; }
+        public string Action { get; set; }
+        public string ActionName { get; set; }
+        public string ControllerName { get; set; }
+        public string ButtonClass { get; set; } = ButtonClassDefault;
+    }
+}

BTCPayServer.Abstractions/Models/DatabaseOptions.cs

@@ -0,0 +1,8 @@
+namespace BTCPayServer.Abstractions.Models
+{
+    public class DatabaseOptions
+    {
+        public DatabaseType DatabaseType { get; set; }
+        public string ConnectionString { get; set; }
+    }
+}

BTCPayServer.Abstractions/Models/DatabaseType.cs

@@ -0,0 +1,9 @@
+namespace BTCPayServer.Abstractions.Models
+{
+    public enum DatabaseType
+    {
+        Sqlite,
+        Postgres,
+        MySQL,
+    }
+}

BTCPayServer.Abstractions/Models/StatusMessageModel.cs

@@ -1,15 +1,12 @@
 using System;
-using Newtonsoft.Json;
-using Newtonsoft.Json.Linq;
 
-namespace BTCPayServer.Models
+namespace BTCPayServer.Abstractions.Models
 {
     public class StatusMessageModel
     {
         public StatusMessageModel()
         {
         }
-
         public string Message { get; set; }
         public string Html { get; set; }
         public StatusSeverity Severity { get; set; }

BTCPayServer.Abstractions/PushNuget.ps1

@@ -0,0 +1,7 @@
+rm "bin\release\" -Recurse -Force
+dotnet pack --configuration Release --include-symbols -p:SymbolPackageFormat=snupkg
+$package=(ls .\bin\Release\*.nupkg).FullName
+dotnet nuget push $package --source "https://api.nuget.org/v3/index.json"
+$ver = ((ls .\bin\release\*.nupkg)[0].Name -replace '.*(\d+\.\d+\.\d+)\.nupkg','$1')
+git tag -a "BTCPayServer.Abstractions/v$ver" -m "BTCPayServer.Abstractions/$ver"
+git push origin "BTCPayServer.Abstractions/v$ver"

BTCPayServer.Abstractions/Security/AuthorizationFilterHandle.cs

@@ -0,0 +1,27 @@
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Http;
+
+namespace BTCPayServer.Security;
+
+public class AuthorizationFilterHandle
+{
+    public AuthorizationHandlerContext Context { get; }
+    public PolicyRequirement Requirement { get; }
+    public HttpContext HttpContext { get; }
+    public bool Success { get; private set; }
+
+    public AuthorizationFilterHandle(
+        AuthorizationHandlerContext context,
+        PolicyRequirement requirement,
+        HttpContext httpContext)
+    {
+        Context = context;
+        Requirement = requirement;
+        HttpContext = httpContext;
+    }
+
+    public void MarkSuccessful()
+    {
+        Success = true;
+    }
+}

BTCPayServer.Abstractions/Security/ContentSecurityPolicies.cs

@@ -1,8 +1,8 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;
-using System.Threading.Tasks;
+using NBitcoin.Crypto;
 
 namespace BTCPayServer.Security
 {
@@ -10,6 +10,8 @@ namespace BTCPayServer.Security
     {
         public ConsentSecurityPolicy(string name, string value)
         {
+            if (value.Contains(';', StringComparison.OrdinalIgnoreCase))
+                throw new FormatException();
             _Value = value;
             _Name = name;
         }
@@ -66,11 +68,49 @@ namespace BTCPayServer.Security
         {
 
         }
-        HashSet<ConsentSecurityPolicy> _Policies = new HashSet<ConsentSecurityPolicy>();
+
+        readonly HashSet<ConsentSecurityPolicy> _Policies = new HashSet<ConsentSecurityPolicy>();
+
+        /// <summary>
+        /// Allow a specific script as event handler
+        /// </summary>
+        /// <param name="script"></param>
+        public void AllowUnsafeHashes(string script = null)
+        {
+            if (!allowUnsafeHashes)
+            {
+                Add("script-src", $"'unsafe-hashes'");
+                allowUnsafeHashes = true;
+            }
+            if (script != null)
+            {
+                var sha = GetSha256(script);
+                Add("script-src", $"'sha256-{sha}'");
+            }
+        }
+
+        bool allowUnsafeHashes = false;
+        /// <summary>
+        /// Allow the injection of script tag with the following script
+        /// </summary>
+        /// <param name="script"></param>
+        public void AllowInline(string script)
+        {
+            ArgumentNullException.ThrowIfNull(script);
+            var sha = GetSha256(script);
+            Add("script-src", $"'sha256-{sha}'");
+        }
+        static string GetSha256(string script)
+        {
+            return Convert.ToBase64String(Hashes.SHA256(Encoding.UTF8.GetBytes(script.Replace("\r\n", "\n", StringComparison.Ordinal))));
+        }
+
+        public void Add(string name, string value)
+        {
+            Add(new ConsentSecurityPolicy(name, value));
+        }
         public void Add(ConsentSecurityPolicy policy)
         {
-            if (_Policies.Any(p => p.Name == policy.Name && p.Value == policy.Name))
-                return;
             _Policies.Add(policy);
         }
 
@@ -81,40 +121,25 @@ namespace BTCPayServer.Security
         {
             StringBuilder value = new StringBuilder();
             bool firstGroup = true;
-            foreach(var group in Rules.GroupBy(r => r.Name))
+            foreach (var group in Rules.GroupBy(r => r.Name))
             {
                 if (!firstGroup)
                 {
                     value.Append(';');
                 }
-                List<string> values = new List<string>();
+                HashSet<string> values = new HashSet<string>();
+                List<string> valuesList = new List<string>();
                 values.Add(group.Key);
+                valuesList.Add(group.Key);
                 foreach (var v in group)
                 {
-                    values.Add(v.Value);
+                    if (values.Add(v.Value))
+                        valuesList.Add(v.Value);
                 }
-                foreach(var i in authorized)
-                {
-                    values.Add(i);
-                }
-                value.Append(String.Join(" ", values.OfType<object>().ToArray()));
+                value.Append(String.Join(" ", valuesList.OfType<object>().ToArray()));
                 firstGroup = false;
             }
             return value.ToString();
         }
-
-        internal void Clear()
-        {
-            authorized.Clear();
-            _Policies.Clear();
-        }
-
-        HashSet<string> authorized = new HashSet<string>();
-        internal void AddAllAuthorized(string v)
-        {
-            authorized.Add(v);
-        }
-
-        public IEnumerable<string> Authorized => authorized;
     }
 }

BTCPayServer.Abstractions/Security/PolicyRequirement.cs

@@ -1,7 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading.Tasks;
+using System;
 using Microsoft.AspNetCore.Authorization;
 
 namespace BTCPayServer.Security
@@ -10,8 +7,7 @@ namespace BTCPayServer.Security
     {
         public PolicyRequirement(string policy)
         {
-            if (policy == null)
-                throw new ArgumentNullException(nameof(policy));
+            ArgumentNullException.ThrowIfNull(policy);
             Policy = policy;
         }
         public string Policy { get; }

BTCPayServer.Abstractions/Services/PluginAction.cs

@@ -0,0 +1,16 @@
+using System.Threading.Tasks;
+using BTCPayServer.Abstractions.Contracts;
+
+namespace BTCPayServer.Abstractions.Services
+{
+    public abstract class PluginAction<T> : IPluginHookAction
+    {
+        public abstract string Hook { get; }
+        public Task Execute(object args)
+        {
+            return Execute(args is T args1 ? args1 : default);
+        }
+
+        public abstract Task Execute(T arg);
+    }
+}

BTCPayServer.Abstractions/Services/PluginHookFilter.cs

@@ -0,0 +1,17 @@
+using System.Threading.Tasks;
+using BTCPayServer.Abstractions.Contracts;
+
+namespace BTCPayServer.Abstractions.Services
+{
+    public abstract class PluginHookFilter<T> : IPluginHookFilter
+    {
+        public abstract string Hook { get; }
+
+        public Task<object> Execute(object args)
+        {
+            return Execute(args is T args1 ? args1 : default).ContinueWith(task => task.Result as object);
+        }
+
+        public abstract Task<T> Execute(T arg);
+    }
+}

BTCPayServer.Abstractions/Services/Safe.cs

@@ -1,12 +1,8 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading.Tasks;
 using Ganss.XSS;
 using Microsoft.AspNetCore.Html;
 using Microsoft.AspNetCore.Mvc.Rendering;
 
-namespace BTCPayServer.Services
+namespace BTCPayServer.Abstractions.Services
 {
     public class Safe
     {

BTCPayServer.Abstractions/Services/UIExtension.cs

@@ -0,0 +1,16 @@
+using BTCPayServer.Abstractions.Contracts;
+
+namespace BTCPayServer.Abstractions.Services
+{
+    public class UIExtension : IUIExtension
+    {
+        public UIExtension(string partial, string location)
+        {
+            Partial = partial;
+            Location = location;
+        }
+
+        public string Partial { get; }
+        public string Location { get; }
+    }
+}

BTCPayServer.Abstractions/TagHelpers/CSPA.cs

@@ -0,0 +1,30 @@
+using System;
+using BTCPayServer.Security;
+using Microsoft.AspNetCore.Razor.TagHelpers;
+
+namespace BTCPayServer.Abstractions.TagHelpers;
+
+/// <summary>
+/// Add sha256- to allow inline event handlers in a:href=javascript:
+/// </summary>
+[HtmlTargetElement("a", Attributes = "csp-allow")]
+public class CSPA : TagHelper
+{
+    private readonly ContentSecurityPolicies _csp;
+    public CSPA(ContentSecurityPolicies csp)
+    {
+        _csp = csp;
+    }
+    public override void Process(TagHelperContext context, TagHelperOutput output)
+    {
+        output.Attributes.RemoveAll("csp-allow");
+        if (output.Attributes.TryGetAttribute("href", out var attr))
+        {
+            var v = attr.Value.ToString();
+            if (v.StartsWith("javascript:", StringComparison.OrdinalIgnoreCase))
+            {
+                _csp.AllowUnsafeHashes(v);
+            }
+        }
+    }
+}

BTCPayServer.Abstractions/TagHelpers/CSPEventTagHelper.cs

@@ -0,0 +1,37 @@
+using System.Collections.Generic;
+using System.Linq;
+using BTCPayServer.Security;
+using Microsoft.AspNetCore.Razor.TagHelpers;
+
+namespace BTCPayServer.Abstractions.TagHelpers;
+
+/// <summary>
+/// Add 'unsafe-hashes' and sha256- to allow inline event handlers in CSP
+/// </summary>
+[HtmlTargetElement(Attributes = "onclick")]
+[HtmlTargetElement(Attributes = "onkeypress")]
+[HtmlTargetElement(Attributes = "onchange")]
+[HtmlTargetElement(Attributes = "onsubmit")]
+public class CSPEventTagHelper : TagHelper
+{
+    public const string EventNames = "onclick,onkeypress,onchange,onsubmit";
+    private readonly ContentSecurityPolicies _csp;
+
+    readonly static HashSet<string> EventSet = EventNames.Split(',')
+                                                .ToHashSet();
+    public CSPEventTagHelper(ContentSecurityPolicies csp)
+    {
+        _csp = csp;
+    }
+    public override void Process(TagHelperContext context, TagHelperOutput output)
+    {
+        foreach (var attr in output.Attributes)
+        {
+            var n = attr.Name.ToLowerInvariant();
+            if (EventSet.Contains(n))
+            {
+                _csp.AllowUnsafeHashes(attr.Value.ToString());
+            }
+        }
+    }
+}

BTCPayServer.Abstractions/TagHelpers/CSPInlineScriptTagHelper.cs

@@ -0,0 +1,33 @@
+using BTCPayServer.Security;
+using Microsoft.AspNetCore.Razor.TagHelpers;
+using NBitcoin;
+
+namespace BTCPayServer.Abstractions.TagHelpers;
+
+/// <summary>
+/// Add a nonce-* so the inline-script can pass CSP rule when they are rendered server-side
+/// </summary>
+[HtmlTargetElement("script")]
+public class CSPInlineScriptTagHelper : TagHelper
+{
+    private readonly ContentSecurityPolicies _csp;
+
+    public CSPInlineScriptTagHelper(ContentSecurityPolicies csp)
+    {
+        _csp = csp;
+    }
+
+    public override void Process(TagHelperContext context, TagHelperOutput output)
+    {
+        if (output.Attributes.ContainsName("src"))
+            return;
+        if (output.Attributes.TryGetAttribute("type", out var attr))
+        {
+            if (attr.Value?.ToString() != "text/javascript")
+                return;
+        }
+        var nonce = RandomUtils.GetUInt256().ToString().Substring(0, 32);
+        output.Attributes.Add(new TagHelperAttribute("nonce", nonce));
+        _csp.Add("script-src", $"'nonce-{nonce}'");
+    }
+}

BTCPayServer.Abstractions/TagHelpers/CSPTemplate.cs

@@ -0,0 +1,25 @@
+using System.Threading.Tasks;
+using BTCPayServer.Security;
+using Microsoft.AspNetCore.Razor.TagHelpers;
+
+namespace BTCPayServer.Abstractions.TagHelpers;
+
+/// <summary>
+/// Add sha256- to allow inline event handlers in CSP
+/// </summary>
+[HtmlTargetElement("template", Attributes = "csp-allow")]
+public class CSPTemplate : TagHelper
+{
+    private readonly ContentSecurityPolicies _csp;
+    public CSPTemplate(ContentSecurityPolicies csp)
+    {
+        _csp = csp;
+    }
+    public override async Task ProcessAsync(TagHelperContext context, TagHelperOutput output)
+    {
+        output.Attributes.RemoveAll("csp-allow");
+        var childContent = await output.GetChildContentAsync();
+        var content = childContent.GetContent();
+        _csp.AllowInline(content);
+    }
+}

BTCPayServer.Abstractions/TagHelpers/PermissionTagHelper.cs

@@ -0,0 +1,48 @@
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Razor.TagHelpers;
+using Microsoft.Extensions.Logging;
+
+namespace BTCPayServer.Abstractions.TagHelpers;
+
+[HtmlTargetElement(Attributes = nameof(Permission))]
+public class PermissionTagHelper : TagHelper
+{
+    private readonly IAuthorizationService _authorizationService;
+    private readonly IHttpContextAccessor _httpContextAccessor;
+    private readonly ILogger<PermissionTagHelper> _logger;
+
+    public PermissionTagHelper(IAuthorizationService authorizationService, IHttpContextAccessor httpContextAccessor, ILogger<PermissionTagHelper> logger)
+    {
+        _authorizationService = authorizationService;
+        _httpContextAccessor = httpContextAccessor;
+        _logger = logger;
+    }
+
+    public string Permission { get; set; }
+    public string PermissionResource { get; set; }
+
+    public override async Task ProcessAsync(TagHelperContext context, TagHelperOutput output)
+    {
+        if (string.IsNullOrEmpty(Permission))
+            return;
+        if (_httpContextAccessor.HttpContext is null)
+            return;
+
+        var key = $"{Permission}_{PermissionResource}";
+        if (!_httpContextAccessor.HttpContext.Items.TryGetValue(key, out var o) ||
+            o is not AuthorizationResult res)
+        {
+            res = await _authorizationService.AuthorizeAsync(_httpContextAccessor.HttpContext.User,
+                PermissionResource,
+                Permission);
+            _httpContextAccessor.HttpContext.Items.Add(key, res);
+        }
+        if (!res.Succeeded)
+        {
+            output.SuppressOutput();
+        }
+
+    }
+}

BTCPayServer.Abstractions/TagHelpers/SVGUse.cs

@@ -0,0 +1,33 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
+using System.IO;
+using System.Text.Encodings.Web;
+using Microsoft.AspNetCore.Html;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.AspNetCore.Mvc.Razor.TagHelpers;
+using Microsoft.AspNetCore.Mvc.Rendering;
+using Microsoft.AspNetCore.Mvc.Routing;
+using Microsoft.AspNetCore.Mvc.ViewFeatures;
+using Microsoft.AspNetCore.Razor.TagHelpers;
+
+namespace BTCPayServer.Abstractions.TagHelpers;
+
+// Make sure that <svg><use href=/ are correctly working if rootpath is present
+[HtmlTargetElement("use", Attributes = "href")]
+public class SVGUse : UrlResolutionTagHelper2
+{
+    private readonly IFileVersionProvider _fileVersionProvider;
+
+    public SVGUse(IUrlHelperFactory urlHelperFactory, HtmlEncoder htmlEncoder, IFileVersionProvider fileVersionProvider) : base(urlHelperFactory, htmlEncoder)
+    {
+        _fileVersionProvider = fileVersionProvider;
+    }
+    public override void Process(TagHelperContext context, TagHelperOutput output)
+    {
+        var attr = output.Attributes["href"].Value.ToString();
+        attr = _fileVersionProvider.AddFileVersionToPath(ViewContext.HttpContext.Request.PathBase, attr);
+        output.Attributes.SetAttribute("href", attr);
+        base.Process(context, output);
+    }
+}

BTCPayServer.Abstractions/TagHelpers/SrvModel.cs

@@ -0,0 +1,31 @@
+using BTCPayServer.Abstractions.Services;
+using BTCPayServer.Security;
+using Microsoft.AspNetCore.Razor.TagHelpers;
+using NBitcoin;
+
+namespace BTCPayServer.Abstractions.TagHelpers;
+
+[HtmlTargetElement("srv-model")]
+public class SrvModel : TagHelper
+{
+    private readonly Safe _safe;
+    private readonly ContentSecurityPolicies _csp;
+
+    public SrvModel(Safe safe, ContentSecurityPolicies csp)
+    {
+        _safe = safe;
+        _csp = csp;
+    }
+    public string VarName { get; set; } = "srvModel";
+    public object Model { get; set; }
+    public override void Process(TagHelperContext context, TagHelperOutput output)
+    {
+        output.TagName = "script";
+        output.TagMode = TagMode.StartTagAndEndTag;
+        output.Attributes.Add(new TagHelperAttribute("type", "text/javascript"));
+        var nonce = RandomUtils.GetUInt256().ToString().Substring(0, 32);
+        output.Attributes.Add(new TagHelperAttribute("nonce", nonce));
+        _csp.Add("script-src", $"'nonce-{nonce}'");
+        output.Content.SetHtmlContent($"var {VarName} = {_safe.Json(Model)};");
+    }
+}

BTCPayServer.Abstractions/TagHelpers/UrlResolutionTagHelper2.cs

@@ -0,0 +1,314 @@
+#nullable enable
+using System;
+using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
+using System.IO;
+using System.Text.Encodings.Web;
+using Microsoft.AspNetCore.Html;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.AspNetCore.Mvc.Razor.TagHelpers;
+using Microsoft.AspNetCore.Mvc.Rendering;
+using Microsoft.AspNetCore.Mvc.Routing;
+using Microsoft.AspNetCore.Mvc.ViewFeatures;
+using Microsoft.AspNetCore.Razor.TagHelpers;
+
+
+namespace BTCPayServer.Abstractions.TagHelpers
+{
+    // A copy of https://github.com/dotnet/aspnetcore/blob/39f0e0b8f40b4754418f81aef0de58a9204a1fe5/src/Mvc/Mvc.Razor/src/TagHelpers/UrlResolutionTagHelper.cs
+    // slightly modified to also work on use tag.
+    public class UrlResolutionTagHelper2 : TagHelper
+    {
+        // Valid whitespace characters defined by the HTML5 spec.
+        private static readonly char[] ValidAttributeWhitespaceChars =
+            new[] { '\t', '\n', '\u000C', '\r', ' ' };
+        private static readonly Dictionary<string, string[]> ElementAttributeLookups =
+            new(StringComparer.OrdinalIgnoreCase)
+            {
+                { "use", new[] { "href" } },
+                { "a", new[] { "href" } },
+                { "applet", new[] { "archive" } },
+                { "area", new[] { "href" } },
+                { "audio", new[] { "src" } },
+                { "base", new[] { "href" } },
+                { "blockquote", new[] { "cite" } },
+                { "button", new[] { "formaction" } },
+                { "del", new[] { "cite" } },
+                { "embed", new[] { "src" } },
+                { "form", new[] { "action" } },
+                { "html", new[] { "manifest" } },
+                { "iframe", new[] { "src" } },
+                { "img", new[] { "src", "srcset" } },
+                { "input", new[] { "src", "formaction" } },
+                { "ins", new[] { "cite" } },
+                { "link", new[] { "href" } },
+                { "menuitem", new[] { "icon" } },
+                { "object", new[] { "archive", "data" } },
+                { "q", new[] { "cite" } },
+                { "script", new[] { "src" } },
+                { "source", new[] { "src", "srcset" } },
+                { "track", new[] { "src" } },
+                { "video", new[] { "poster", "src" } },
+            };
+
+        /// <summary>
+        /// Creates a new <see cref="UrlResolutionTagHelper"/>.
+        /// </summary>
+        /// <param name="urlHelperFactory">The <see cref="IUrlHelperFactory"/>.</param>
+        /// <param name="htmlEncoder">The <see cref="HtmlEncoder"/>.</param>
+        public UrlResolutionTagHelper2(IUrlHelperFactory urlHelperFactory, HtmlEncoder htmlEncoder)
+        {
+            UrlHelperFactory = urlHelperFactory;
+            HtmlEncoder = htmlEncoder;
+        }
+
+        /// <inheritdoc />
+        public override int Order => -1000 - 999;
+
+        /// <summary>
+        /// The <see cref="IUrlHelperFactory"/>.
+        /// </summary>
+        protected IUrlHelperFactory UrlHelperFactory { get; }
+
+        /// <summary>
+        /// The <see cref="HtmlEncoder"/>.
+        /// </summary>
+        protected HtmlEncoder HtmlEncoder { get; }
+
+        /// <summary>
+        /// The <see cref="ViewContext"/>.
+        /// </summary>
+        [HtmlAttributeNotBound]
+        [ViewContext]
+        public ViewContext ViewContext { get; set; } = default!;
+
+        /// <inheritdoc />
+        public override void Process(TagHelperContext context, TagHelperOutput output)
+        {
+            ArgumentNullException.ThrowIfNull(context);
+            ArgumentNullException.ThrowIfNull(output);
+
+            if (output.TagName == null)
+            {
+                return;
+            }
+
+            if (ElementAttributeLookups.TryGetValue(output.TagName, out var attributeNames))
+            {
+                for (var i = 0; i < attributeNames.Length; i++)
+                {
+                    ProcessUrlAttribute(attributeNames[i], output);
+                }
+            }
+
+            // itemid can be present on any HTML element.
+            ProcessUrlAttribute("itemid", output);
+        }
+
+        /// <summary>
+        /// Resolves and updates URL values starting with '~/' (relative to the application's 'webroot' setting) for
+        /// <paramref name="output"/>'s <see cref="TagHelperOutput.Attributes"/> whose
+        /// <see cref="TagHelperAttribute.Name"/> is <paramref name="attributeName"/>.
+        /// </summary>
+        /// <param name="attributeName">The attribute name used to lookup values to resolve.</param>
+        /// <param name="output">The <see cref="TagHelperOutput"/>.</param>
+        protected void ProcessUrlAttribute(string attributeName, TagHelperOutput output)
+        {
+            ArgumentNullException.ThrowIfNull(attributeName);
+            ArgumentNullException.ThrowIfNull(output);
+
+            var attributes = output.Attributes;
+            // Read interface .Count once rather than per iteration
+            var attributesCount = attributes.Count;
+            for (var i = 0; i < attributesCount; i++)
+            {
+                var attribute = attributes[i];
+                if (!string.Equals(attribute.Name, attributeName, StringComparison.OrdinalIgnoreCase))
+                {
+                    continue;
+                }
+
+                if (attribute.Value is string stringValue)
+                {
+                    if (TryResolveUrl(stringValue, resolvedUrl: out string? resolvedUrl))
+                    {
+                        attributes[i] = new TagHelperAttribute(
+                            attribute.Name,
+                            resolvedUrl,
+                            attribute.ValueStyle);
+                    }
+                }
+                else
+                {
+                    if (attribute.Value is IHtmlContent htmlContent)
+                    {
+                        var htmlString = htmlContent as HtmlString;
+                        if (htmlString != null)
+                        {
+                            // No need for a StringWriter in this case.
+                            stringValue = htmlString.ToString();
+                        }
+                        else
+                        {
+                            using var writer = new StringWriter();
+                            htmlContent.WriteTo(writer, HtmlEncoder);
+                            stringValue = writer.ToString();
+                        }
+
+                        if (TryResolveUrl(stringValue, resolvedUrl: out IHtmlContent? resolvedUrl))
+                        {
+                            attributes[i] = new TagHelperAttribute(
+                                attribute.Name,
+                                resolvedUrl,
+                                attribute.ValueStyle);
+                        }
+                        else if (htmlString == null)
+                        {
+                            // Not a ~/ URL. Just avoid re-encoding the attribute value later.
+                            attributes[i] = new TagHelperAttribute(
+                                attribute.Name,
+                                new HtmlString(stringValue),
+                                attribute.ValueStyle);
+                        }
+                    }
+                }
+            }
+        }
+
+        /// <summary>
+        /// Tries to resolve the given <paramref name="url"/> value relative to the application's 'webroot' setting.
+        /// </summary>
+        /// <param name="url">The URL to resolve.</param>
+        /// <param name="resolvedUrl">Absolute URL beginning with the application's virtual root. <c>null</c> if
+        /// <paramref name="url"/> could not be resolved.</param>
+        /// <returns><c>true</c> if the <paramref name="url"/> could be resolved; <c>false</c> otherwise.</returns>
+        protected bool TryResolveUrl(string url, out string? resolvedUrl)
+        {
+            resolvedUrl = null;
+            var start = FindRelativeStart(url);
+            if (start == -1)
+            {
+                return false;
+            }
+
+            var trimmedUrl = CreateTrimmedString(url, start);
+
+            var urlHelper = UrlHelperFactory.GetUrlHelper(ViewContext);
+            resolvedUrl = urlHelper.Content(trimmedUrl);
+
+            return true;
+        }
+
+        /// <summary>
+        /// Tries to resolve the given <paramref name="url"/> value relative to the application's 'webroot' setting.
+        /// </summary>
+        /// <param name="url">The URL to resolve.</param>
+        /// <param name="resolvedUrl">
+        /// Absolute URL beginning with the application's virtual root. <c>null</c> if <paramref name="url"/> could
+        /// not be resolved.
+        /// </param>
+        /// <returns><c>true</c> if the <paramref name="url"/> could be resolved; <c>false</c> otherwise.</returns>
+        protected bool TryResolveUrl(string url, [NotNullWhen(true)] out IHtmlContent? resolvedUrl)
+        {
+            resolvedUrl = null;
+            var start = FindRelativeStart(url);
+            if (start == -1)
+            {
+                return false;
+            }
+
+            var trimmedUrl = CreateTrimmedString(url, start);
+
+            var urlHelper = UrlHelperFactory.GetUrlHelper(ViewContext);
+            var appRelativeUrl = urlHelper.Content(trimmedUrl);
+            var postTildeSlashUrlValue = trimmedUrl.Substring(2);
+
+            if (!appRelativeUrl.EndsWith(postTildeSlashUrlValue, StringComparison.Ordinal))
+            {
+                throw new InvalidOperationException();
+            }
+
+            resolvedUrl = new EncodeFirstSegmentContent(
+                appRelativeUrl,
+                appRelativeUrl.Length - postTildeSlashUrlValue.Length,
+                postTildeSlashUrlValue);
+
+            return true;
+        }
+
+        private static int FindRelativeStart(string url)
+        {
+            if (url == null || url.Length < 2)
+            {
+                return -1;
+            }
+
+            var maxTestLength = url.Length - 2;
+
+            var start = 0;
+            for (; start < url.Length; start++)
+            {
+                if (start > maxTestLength)
+                {
+                    return -1;
+                }
+
+                if (!IsCharWhitespace(url[start]))
+                {
+                    break;
+                }
+            }
+
+            // Before doing more work, ensure that the URL we're looking at is app-relative.
+            if (url[start] != '~' || url[start + 1] != '/')
+            {
+                return -1;
+            }
+
+            return start;
+        }
+
+        private static string CreateTrimmedString(string input, int start)
+        {
+            var end = input.Length - 1;
+            for (; end >= start; end--)
+            {
+                if (!IsCharWhitespace(input[end]))
+                {
+                    break;
+                }
+            }
+
+            var len = end - start + 1;
+
+            // Substring returns same string if start == 0 && len == Length
+            return input.Substring(start, len);
+        }
+
+        private static bool IsCharWhitespace(char ch)
+        {
+            return ValidAttributeWhitespaceChars.AsSpan().IndexOf(ch) != -1;
+        }
+
+        private sealed class EncodeFirstSegmentContent : IHtmlContent
+        {
+            private readonly string _firstSegment;
+            private readonly int _firstSegmentLength;
+            private readonly string _secondSegment;
+
+            public EncodeFirstSegmentContent(string firstSegment, int firstSegmentLength, string secondSegment)
+            {
+                _firstSegment = firstSegment;
+                _firstSegmentLength = firstSegmentLength;
+                _secondSegment = secondSegment;
+            }
+
+            public void WriteTo(TextWriter writer, HtmlEncoder encoder)
+            {
+                encoder.Encode(writer, _firstSegment, 0, _firstSegmentLength);
+                writer.Write(_secondSegment);
+            }
+        }
+    }
+
+}

BTCPayServer.Client/BTCPayServer.Client.csproj

@@ -1,12 +1,38 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
     <PropertyGroup>
         <TargetFramework>netstandard2.1</TargetFramework>
+        <LangVersion>10.0</LangVersion>
+        <Company>BTCPay Server</Company>
+        <Copyright>Copyright © BTCPay Server 2020</Copyright>
+        <Description>A client library for BTCPay Server Greenfield API</Description>
+        <PackageIcon>icon.png</PackageIcon>
+        <PackageTags>btcpay,btcpayserver</PackageTags>
+        <PackageProjectUrl>https://github.com/btcpayserver/btcpayserver/tree/master/BTCPayServer.Client</PackageProjectUrl>
+        <PackageLicenseExpression>MIT</PackageLicenseExpression>
+        <RepositoryUrl>https://github.com/btcpayserver/btcpayserver</RepositoryUrl>
+        <RepositoryType>git</RepositoryType>
     </PropertyGroup>
-
+  <PropertyGroup>
+    <Version Condition=" '$(Version)' == '' ">1.7.2</Version>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)' == 'Release' ">
+    <PublishRepositoryUrl>true</PublishRepositoryUrl>
+    <EmbedUntrackedSources>true</EmbedUntrackedSources>
+    <DebugType>portable</DebugType>
+    <Optimize>true</Optimize>
+    <NoWarn>1591;1573;1572;1584;1570;3021</NoWarn>
+    <GenerateDocumentationFile>true</GenerateDocumentationFile>
+  </PropertyGroup>
+  <ItemGroup Condition=" '$(Configuration)' == 'Release' ">
+    <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.0.0" PrivateAssets="All" />
+  </ItemGroup>
     <ItemGroup>
-      <PackageReference Include="NBitcoin" Version="5.0.29" />
-      <PackageReference Include="Newtonsoft.Json" Version="12.0.3" />
+      <PackageReference Include="BTCPayServer.Lightning.Common" Version="1.3.21" />
+      <PackageReference Include="NBitcoin" Version="7.0.24" />
+      <PackageReference Include="Newtonsoft.Json" Version="13.0.1" />
     </ItemGroup>
-
+  <ItemGroup>
+    <None Include="icon.png" Pack="true" PackagePath="\" />
+  </ItemGroup>
 </Project>

BTCPayServer.Client/BTCPayServerClient.APIKeys.cs

@@ -25,7 +25,7 @@ namespace BTCPayServer.Client
         public virtual async Task RevokeCurrentAPIKeyInfo(CancellationToken token = default)
         {
             var response = await _httpClient.SendAsync(CreateHttpRequest("api/v1/api-keys/current", null, HttpMethod.Delete), token);
-            HandleResponse(response);
+            await HandleResponse(response);
         }
 
         public virtual async Task RevokeAPIKey(string apikey, CancellationToken token = default)
@@ -33,7 +33,7 @@ namespace BTCPayServer.Client
             if (apikey == null)
                 throw new ArgumentNullException(nameof(apikey));
             var response = await _httpClient.SendAsync(CreateHttpRequest($"api/v1/api-keys/{apikey}", null, HttpMethod.Delete), token);
-            HandleResponse(response);
+            await HandleResponse(response);
         }
     }
 }

BTCPayServer.Client/BTCPayServerClient.Apps.cs

@@ -0,0 +1,103 @@
+using System;
+using System.Net.Http;
+using System.Threading;
+using System.Threading.Tasks;
+using BTCPayServer.Client.Models;
+
+namespace BTCPayServer.Client
+{
+    public partial class BTCPayServerClient
+    {
+
+        public virtual async Task<PointOfSaleAppData> CreatePointOfSaleApp(string storeId,
+            CreatePointOfSaleAppRequest request, CancellationToken token = default)
+        {
+            if (request == null)
+                throw new ArgumentNullException(nameof(request));
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/stores/{storeId}/apps/pos", bodyPayload: request,
+                    method: HttpMethod.Post), token);
+            return await HandleResponse<PointOfSaleAppData>(response);
+        }
+
+        public virtual async Task<CrowdfundAppData> CreateCrowdfundApp(string storeId,
+            CreateCrowdfundAppRequest request, CancellationToken token = default)
+        {
+            if (request == null)
+                throw new ArgumentNullException(nameof(request));
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/stores/{storeId}/apps/crowdfund", bodyPayload: request,
+                    method: HttpMethod.Post), token);
+            return await HandleResponse<CrowdfundAppData>(response);
+        }
+
+        public virtual async Task<PointOfSaleAppData> UpdatePointOfSaleApp(string appId,
+            CreatePointOfSaleAppRequest request, CancellationToken token = default)
+        {
+            if (request == null)
+                throw new ArgumentNullException(nameof(request));
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/apps/pos/{appId}", bodyPayload: request,
+                    method: HttpMethod.Put), token);
+            return await HandleResponse<PointOfSaleAppData>(response);
+        }
+
+        public virtual async Task<AppDataBase> GetApp(string appId, CancellationToken token = default)
+        {
+            if (appId == null)
+                throw new ArgumentNullException(nameof(appId));
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/apps/{appId}",
+                    method: HttpMethod.Get), token);
+            return await HandleResponse<AppDataBase>(response);
+        }
+        
+        public virtual async Task<AppDataBase[]> GetAllApps(string storeId, CancellationToken token = default)
+        {
+            if (storeId == null)
+                throw new ArgumentNullException(nameof(storeId));
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/stores/{storeId}/apps",
+                    method: HttpMethod.Get), token);
+            return await HandleResponse<AppDataBase[]>(response);
+        }
+
+        public virtual async Task<AppDataBase[]> GetAllApps(CancellationToken token = default)
+        {
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/apps",
+                    method: HttpMethod.Get), token);
+            return await HandleResponse<AppDataBase[]>(response);
+        }
+
+        public virtual async Task<PointOfSaleAppData> GetPosApp(string appId, CancellationToken token = default)
+        {
+            if (appId == null)
+                throw new ArgumentNullException(nameof(appId));
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/apps/pos/{appId}",
+                    method: HttpMethod.Get), token);
+            return await HandleResponse<PointOfSaleAppData>(response);
+        }
+
+        public virtual async Task<CrowdfundAppData> GetCrowdfundApp(string appId, CancellationToken token = default)
+        {
+            if (appId == null)
+                throw new ArgumentNullException(nameof(appId));
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/apps/crowdfund/{appId}",
+                    method: HttpMethod.Get), token);
+            return await HandleResponse<CrowdfundAppData>(response);
+        }
+
+        public virtual async Task DeleteApp(string appId, CancellationToken token = default)
+        {
+            if (appId == null)
+                throw new ArgumentNullException(nameof(appId));
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/apps/{appId}",
+                    method: HttpMethod.Delete), token);
+            await HandleResponse(response);
+        }
+    }
+}

BTCPayServer.Client/BTCPayServerClient.Authorization.cs

@@ -1,13 +1,14 @@
 using System;
 using System.Collections.Generic;
+using System.Threading.Tasks;
 
 namespace BTCPayServer.Client
 {
     public partial class BTCPayServerClient
     {
-    
+
         public static Uri GenerateAuthorizeUri(Uri btcpayHost, string[] permissions, bool strict = true,
-            bool selectiveStores = false)
+            bool selectiveStores = false, (string ApplicationIdentifier, Uri Redirect) applicationDetails = default)
         {
             var result = new UriBuilder(btcpayHost);
             result.Path = "api-keys/authorize";
@@ -18,6 +19,15 @@ namespace BTCPayServer.Client
                     {"strict", strict}, {"selectiveStores", selectiveStores}, {"permissions", permissions}
                 });
 
+            if (applicationDetails.Redirect != null)
+            {
+                AppendPayloadToQuery(result, new KeyValuePair<string, object>("redirect", applicationDetails.Redirect));
+                if (!string.IsNullOrEmpty(applicationDetails.ApplicationIdentifier))
+                {
+                    AppendPayloadToQuery(result, new KeyValuePair<string, object>("applicationIdentifier", applicationDetails.ApplicationIdentifier));
+                }
+            }
+
             return result.Uri;
         }
     }

BTCPayServer.Client/BTCPayServerClient.CustodianAccounts.cs

@@ -0,0 +1,97 @@
+using System.Collections.Generic;
+using System.Net.Http;
+using System.Threading;
+using System.Threading.Tasks;
+using BTCPayServer.Client.Models;
+
+namespace BTCPayServer.Client
+{
+    public partial class BTCPayServerClient
+    {
+        public virtual async Task<IEnumerable<CustodianAccountData>> GetCustodianAccounts(string storeId, bool includeAssetBalances = false, CancellationToken token = default)
+        {
+            var queryPayload = new Dictionary<string, object>();
+            if (includeAssetBalances)
+            {
+                queryPayload.Add("assetBalances", "true");
+            }
+
+            var response = await _httpClient.SendAsync(CreateHttpRequest($"api/v1/stores/{storeId}/custodian-accounts", queryPayload), token);
+            return await HandleResponse<IEnumerable<CustodianAccountData>>(response);
+        }
+
+        public virtual async Task<CustodianAccountResponse> GetCustodianAccount(string storeId, string accountId, bool includeAssetBalances = false, CancellationToken token = default)
+        {
+            var queryPayload = new Dictionary<string, object>();
+            if (includeAssetBalances)
+            {
+                queryPayload.Add("assetBalances", "true");
+            }
+
+            var response = await _httpClient.SendAsync(CreateHttpRequest($"api/v1/stores/{storeId}/custodian-accounts/{accountId}", queryPayload), token);
+            return await HandleResponse<CustodianAccountResponse>(response);
+        }
+
+        public virtual async Task<CustodianAccountData> CreateCustodianAccount(string storeId, CreateCustodianAccountRequest request, CancellationToken token = default)
+        {
+            var response = await _httpClient.SendAsync(CreateHttpRequest($"api/v1/stores/{storeId}/custodian-accounts", bodyPayload: request, method: HttpMethod.Post), token);
+            return await HandleResponse<CustodianAccountData>(response);
+        }
+
+        public virtual async Task<CustodianAccountData> UpdateCustodianAccount(string storeId, string accountId, CreateCustodianAccountRequest request, CancellationToken token = default)
+        {
+            var response = await _httpClient.SendAsync(CreateHttpRequest($"api/v1/stores/{storeId}/custodian-accounts/{accountId}", bodyPayload: request, method: HttpMethod.Put), token);
+            return await HandleResponse<CustodianAccountData>(response);
+        }
+
+        public virtual async Task DeleteCustodianAccount(string storeId, string accountId, CancellationToken token = default)
+        {
+            var response = await _httpClient.SendAsync(CreateHttpRequest($"api/v1/stores/{storeId}/custodian-accounts/{accountId}", method: HttpMethod.Delete), token);
+            await HandleResponse(response);
+        }
+
+        public virtual async Task<DepositAddressData> GetDepositAddress(string storeId, string accountId, string paymentMethod, CancellationToken token = default)
+        {
+            var response = await _httpClient.SendAsync(CreateHttpRequest($"api/v1/stores/{storeId}/custodian-accounts/{accountId}/addresses/{paymentMethod}"), token);
+            return await HandleResponse<DepositAddressData>(response);
+        }
+
+        public virtual async Task<MarketTradeResponseData> MarketTradeCustodianAccountAsset(string storeId, string accountId, TradeRequestData request, CancellationToken token = default)
+        {
+
+            //var response = await _httpClient.SendAsync(CreateHttpRequest("api/v1/users", null, request, HttpMethod.Post), token);
+            //return await HandleResponse<ApplicationUserData>(response);
+            var internalRequest = CreateHttpRequest($"api/v1/stores/{storeId}/custodian-accounts/{accountId}/trades/market", null,
+                    request, HttpMethod.Post);
+            var response = await _httpClient.SendAsync(internalRequest, token);
+            return await HandleResponse<MarketTradeResponseData>(response);
+        }
+
+        public virtual async Task<MarketTradeResponseData> GetTradeInfo(string storeId, string accountId, string tradeId, CancellationToken token = default)
+        {
+            var response = await _httpClient.SendAsync(CreateHttpRequest($"api/v1/stores/{storeId}/custodian-accounts/{accountId}/trades/{tradeId}", method: HttpMethod.Get), token);
+            return await HandleResponse<MarketTradeResponseData>(response);
+        }
+
+        public virtual async Task<TradeQuoteResponseData> GetTradeQuote(string storeId, string accountId, string fromAsset, string toAsset, CancellationToken token = default)
+        {
+            var queryPayload = new Dictionary<string, object>();
+            queryPayload.Add("fromAsset", fromAsset);
+            queryPayload.Add("toAsset", toAsset);
+            var response = await _httpClient.SendAsync(CreateHttpRequest($"api/v1/stores/{storeId}/custodian-accounts/{accountId}/trades/quote", queryPayload), token);
+            return await HandleResponse<TradeQuoteResponseData>(response);
+        }
+
+        public virtual async Task<WithdrawalResponseData> CreateWithdrawal(string storeId, string accountId, WithdrawRequestData request, CancellationToken token = default)
+        {
+            var response = await _httpClient.SendAsync(CreateHttpRequest($"api/v1/stores/{storeId}/custodian-accounts/{accountId}/withdrawals", bodyPayload: request, method: HttpMethod.Post), token);
+            return await HandleResponse<WithdrawalResponseData>(response);
+        }
+
+        public virtual async Task<WithdrawalResponseData> GetWithdrawalInfo(string storeId, string accountId, string paymentMethod, string withdrawalId, CancellationToken token = default)
+        {
+            var response = await _httpClient.SendAsync(CreateHttpRequest($"api/v1/stores/{storeId}/custodian-accounts/{accountId}/withdrawals/{paymentMethod}/{withdrawalId}", method: HttpMethod.Get), token);
+            return await HandleResponse<WithdrawalResponseData>(response);
+        }
+    }
+}

BTCPayServer.Client/BTCPayServerClient.Custodians.cs

@@ -0,0 +1,16 @@
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+using BTCPayServer.Client.Models;
+
+namespace BTCPayServer.Client
+{
+    public partial class BTCPayServerClient
+    {
+        public virtual async Task<IEnumerable<CustodianData>> GetCustodians(CancellationToken token = default)
+        {
+            var response = await _httpClient.SendAsync(CreateHttpRequest("api/v1/custodians"), token);
+            return await HandleResponse<IEnumerable<CustodianData>>(response);
+        }
+    }
+}

BTCPayServer.Client/BTCPayServerClient.Health.cs

@@ -0,0 +1,15 @@
+using System.Threading;
+using System.Threading.Tasks;
+using BTCPayServer.Client.Models;
+
+namespace BTCPayServer.Client
+{
+    public partial class BTCPayServerClient
+    {
+        public virtual async Task<ApiHealthData> GetHealth(CancellationToken token = default)
+        {
+            var response = await _httpClient.SendAsync(CreateHttpRequest("api/v1/health"), token);
+            return await HandleResponse<ApiHealthData>(response);
+        }
+    }
+}

BTCPayServer.Client/BTCPayServerClient.Invoices.cs

@@ -0,0 +1,145 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Net.Http;
+using System.Threading;
+using System.Threading.Tasks;
+using BTCPayServer.Client.Models;
+using NBitcoin;
+
+namespace BTCPayServer.Client
+{
+    public partial class BTCPayServerClient
+    {
+        public virtual async Task<IEnumerable<InvoiceData>> GetInvoices(string storeId, string[] orderId = null,
+            InvoiceStatus[] status = null,
+            DateTimeOffset? startDate = null,
+            DateTimeOffset? endDate = null,
+            string textSearch = null,
+            bool includeArchived = false,
+            int? skip = null,
+            int? take = null,
+            CancellationToken token = default)
+        {
+            Dictionary<string, object> queryPayload = new Dictionary<string, object>();
+            queryPayload.Add(nameof(includeArchived), includeArchived);
+
+            if (startDate is DateTimeOffset s)
+                queryPayload.Add(nameof(startDate), Utils.DateTimeToUnixTime(s));
+
+            if (endDate is DateTimeOffset e)
+                queryPayload.Add(nameof(endDate), Utils.DateTimeToUnixTime(e));
+
+            if (orderId != null)
+                queryPayload.Add(nameof(orderId), orderId);
+            if (textSearch != null)
+                queryPayload.Add(nameof(textSearch), textSearch);
+            if (status != null)
+                queryPayload.Add(nameof(status), status.Select(s => s.ToString().ToLower()).ToArray());
+
+            if (skip != null)
+            {
+                queryPayload.Add(nameof(skip), skip);
+            }
+
+            if (take != null)
+            {
+                queryPayload.Add(nameof(take), take);
+            }
+
+            var response =
+                await _httpClient.SendAsync(
+                    CreateHttpRequest($"api/v1/stores/{storeId}/invoices",
+                        queryPayload), token);
+            return await HandleResponse<IEnumerable<InvoiceData>>(response);
+        }
+
+        public virtual async Task<InvoiceData> GetInvoice(string storeId, string invoiceId,
+            CancellationToken token = default)
+        {
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/stores/{storeId}/invoices/{invoiceId}"), token);
+            return await HandleResponse<InvoiceData>(response);
+        }
+        public virtual async Task<InvoicePaymentMethodDataModel[]> GetInvoicePaymentMethods(string storeId, string invoiceId,
+            CancellationToken token = default)
+        {
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/stores/{storeId}/invoices/{invoiceId}/payment-methods"), token);
+            return await HandleResponse<InvoicePaymentMethodDataModel[]>(response);
+        }
+
+        public virtual async Task ArchiveInvoice(string storeId, string invoiceId,
+            CancellationToken token = default)
+        {
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/stores/{storeId}/invoices/{invoiceId}",
+                    method: HttpMethod.Delete), token);
+            await HandleResponse(response);
+        }
+
+        public virtual async Task<InvoiceData> CreateInvoice(string storeId,
+            CreateInvoiceRequest request, CancellationToken token = default)
+        {
+            if (request == null)
+                throw new ArgumentNullException(nameof(request));
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/stores/{storeId}/invoices", bodyPayload: request,
+                    method: HttpMethod.Post), token);
+            return await HandleResponse<InvoiceData>(response);
+        }
+
+        public virtual async Task<InvoiceData> UpdateInvoice(string storeId, string invoiceId,
+            UpdateInvoiceRequest request, CancellationToken token = default)
+        {
+            if (request == null)
+                throw new ArgumentNullException(nameof(request));
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/stores/{storeId}/invoices/{invoiceId}", bodyPayload: request,
+                    method: HttpMethod.Put), token);
+            return await HandleResponse<InvoiceData>(response);
+        }
+
+        public virtual async Task<InvoiceData> MarkInvoiceStatus(string storeId, string invoiceId,
+            MarkInvoiceStatusRequest request, CancellationToken token = default)
+        {
+            if (request == null)
+                throw new ArgumentNullException(nameof(request));
+            if (request.Status != InvoiceStatus.Settled && request.Status != InvoiceStatus.Invalid)
+                throw new ArgumentOutOfRangeException(nameof(request.Status), "Status can only be Invalid or Complete");
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/stores/{storeId}/invoices/{invoiceId}/status", bodyPayload: request,
+                    method: HttpMethod.Post), token);
+            return await HandleResponse<InvoiceData>(response);
+        }
+
+        public virtual async Task<InvoiceData> UnarchiveInvoice(string storeId, string invoiceId, CancellationToken token = default)
+        {
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/stores/{storeId}/invoices/{invoiceId}/unarchive",
+                    method: HttpMethod.Post), token);
+            return await HandleResponse<InvoiceData>(response);
+        }
+
+        public virtual async Task ActivateInvoicePaymentMethod(string storeId, string invoiceId, string paymentMethod, CancellationToken token = default)
+        {
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/stores/{storeId}/invoices/{invoiceId}/payment-methods/{paymentMethod}/activate",
+                    method: HttpMethod.Post), token);
+            await HandleResponse(response);
+        }
+
+        public virtual async Task<PullPaymentData> RefundInvoice(
+            string storeId,
+            string invoiceId,
+            RefundInvoiceRequest request,
+            CancellationToken token = default
+        )
+        {
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/stores/{storeId}/invoices/{invoiceId}/refund", bodyPayload: request,
+                    method: HttpMethod.Post), token);
+            return await HandleResponse<PullPaymentData>(response);
+        }
+    }
+}

BTCPayServer.Client/BTCPayServerClient.LNURLPayPaymentMethods.cs

@@ -0,0 +1,59 @@
+using System.Collections.Generic;
+using System.Net.Http;
+using System.Threading;
+using System.Threading.Tasks;
+using BTCPayServer.Client.Models;
+
+namespace BTCPayServer.Client
+{
+    public partial class BTCPayServerClient
+    {
+        public virtual async Task<IEnumerable<LNURLPayPaymentMethodData>>
+            GetStoreLNURLPayPaymentMethods(string storeId, bool? enabled = null,
+                CancellationToken token = default)
+        {
+            var query = new Dictionary<string, object>();
+            if (enabled != null)
+            {
+                query.Add(nameof(enabled), enabled);
+            }
+
+            var response =
+                await _httpClient.SendAsync(
+                    CreateHttpRequest($"api/v1/stores/{storeId}/payment-methods/LNURLPay",
+                        query), token);
+            return await HandleResponse<IEnumerable<LNURLPayPaymentMethodData>>(response);
+        }
+
+        public virtual async Task<LNURLPayPaymentMethodData> GetStoreLNURLPayPaymentMethod(
+            string storeId,
+            string cryptoCode, CancellationToken token = default)
+        {
+            var response =
+                await _httpClient.SendAsync(
+                    CreateHttpRequest($"api/v1/stores/{storeId}/payment-methods/LNURLPay/{cryptoCode}"), token);
+            return await HandleResponse<LNURLPayPaymentMethodData>(response);
+        }
+
+        public virtual async Task RemoveStoreLNURLPayPaymentMethod(string storeId,
+            string cryptoCode, CancellationToken token = default)
+        {
+            var response =
+                await _httpClient.SendAsync(
+                    CreateHttpRequest($"api/v1/stores/{storeId}/payment-methods/LNURLPay/{cryptoCode}",
+                        method: HttpMethod.Delete), token);
+            await HandleResponse(response);
+        }
+
+        public virtual async Task<LNURLPayPaymentMethodData> UpdateStoreLNURLPayPaymentMethod(
+            string storeId,
+            string cryptoCode, LNURLPayPaymentMethodData paymentMethod,
+            CancellationToken token = default)
+        {
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/stores/{storeId}/payment-methods/LNURLPay/{cryptoCode}",
+                    bodyPayload: paymentMethod, method: HttpMethod.Put), token);
+            return await HandleResponse<LNURLPayPaymentMethodData>(response);
+        }
+    }
+}

BTCPayServer.Client/BTCPayServerClient.Lightning.Internal.cs

@@ -0,0 +1,146 @@
+using System;
+using System.Collections.Generic;
+using System.Net.Http;
+using System.Threading;
+using System.Threading.Tasks;
+using BTCPayServer.Client.Models;
+
+namespace BTCPayServer.Client
+{
+    public partial class BTCPayServerClient
+    {
+        public virtual async Task<LightningNodeInformationData> GetLightningNodeInfo(string cryptoCode,
+            CancellationToken token = default)
+        {
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/server/lightning/{cryptoCode}/info",
+                    method: HttpMethod.Get), token);
+            return await HandleResponse<LightningNodeInformationData>(response);
+        }
+
+        public virtual async Task<LightningNodeBalanceData> GetLightningNodeBalance(string cryptoCode,
+            CancellationToken token = default)
+        {
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/server/lightning/{cryptoCode}/balance",
+                    method: HttpMethod.Get), token);
+            return await HandleResponse<LightningNodeBalanceData>(response);
+        }
+
+        public virtual async Task ConnectToLightningNode(string cryptoCode, ConnectToNodeRequest request,
+            CancellationToken token = default)
+        {
+            if (request == null)
+                throw new ArgumentNullException(nameof(request));
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/server/lightning/{cryptoCode}/connect", bodyPayload: request,
+                    method: HttpMethod.Post), token);
+            await HandleResponse(response);
+        }
+
+        public virtual async Task<IEnumerable<LightningChannelData>> GetLightningNodeChannels(string cryptoCode,
+            CancellationToken token = default)
+        {
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/server/lightning/{cryptoCode}/channels",
+                    method: HttpMethod.Get), token);
+            return await HandleResponse<IEnumerable<LightningChannelData>>(response);
+        }
+
+        public virtual async Task OpenLightningChannel(string cryptoCode, OpenLightningChannelRequest request,
+            CancellationToken token = default)
+        {
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/server/lightning/{cryptoCode}/channels", bodyPayload: request,
+                    method: HttpMethod.Post), token);
+            await HandleResponse(response);
+        }
+
+        public virtual async Task<string> GetLightningDepositAddress(string cryptoCode, CancellationToken token = default)
+        {
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/server/lightning/{cryptoCode}/address", method: HttpMethod.Post), token);
+            return await HandleResponse<string>(response);
+        }
+
+        public virtual async Task<LightningPaymentData> PayLightningInvoice(string cryptoCode, PayLightningInvoiceRequest request,
+            CancellationToken token = default)
+        {
+            if (request == null)
+                throw new ArgumentNullException(nameof(request));
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/server/lightning/{cryptoCode}/invoices/pay", bodyPayload: request,
+                    method: HttpMethod.Post), token);
+            return await HandleResponse<LightningPaymentData>(response);
+        }
+
+        public virtual async Task<LightningPaymentData> GetLightningPayment(string cryptoCode,
+            string paymentHash, CancellationToken token = default)
+        {
+            if (paymentHash == null)
+                throw new ArgumentNullException(nameof(paymentHash));
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/server/lightning/{cryptoCode}/payments/{paymentHash}",
+                    method: HttpMethod.Get), token);
+            return await HandleResponse<LightningPaymentData>(response);
+        }
+
+        public virtual async Task<LightningInvoiceData> GetLightningInvoice(string cryptoCode,
+            string invoiceId, CancellationToken token = default)
+        {
+            if (invoiceId == null)
+                throw new ArgumentNullException(nameof(invoiceId));
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/server/lightning/{cryptoCode}/invoices/{invoiceId}",
+                    method: HttpMethod.Get), token);
+            return await HandleResponse<LightningInvoiceData>(response);
+        }
+
+        public virtual async Task<LightningInvoiceData[]> GetLightningInvoices(string cryptoCode,
+            bool? pendingOnly = null, long? offsetIndex = null, CancellationToken token = default)
+        {
+            var queryPayload = new Dictionary<string, object>();
+            if (pendingOnly is bool v)
+            {
+                queryPayload.Add("pendingOnly", v.ToString());
+            }
+            if (offsetIndex is > 0)
+            {
+                queryPayload.Add("offsetIndex", offsetIndex);
+            }
+
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/server/lightning/{cryptoCode}/invoices", queryPayload), token);
+            return await HandleResponse<LightningInvoiceData[]>(response);
+        }
+        
+        public virtual async Task<LightningPaymentData[]> GetLightningPayments(string cryptoCode,
+            bool? includePending = null, long? offsetIndex = null, CancellationToken token = default)
+        {
+            var queryPayload = new Dictionary<string, object>();
+            if (includePending is bool v)
+            {
+                queryPayload.Add("includePending", v.ToString());
+            }
+            if (offsetIndex is > 0)
+            {
+                queryPayload.Add("offsetIndex", offsetIndex);
+            }
+
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/server/lightning/{cryptoCode}/payments", queryPayload), token);
+            return await HandleResponse<LightningPaymentData[]>(response);
+        }
+
+        public virtual async Task<LightningInvoiceData> CreateLightningInvoice(string cryptoCode, CreateLightningInvoiceRequest request,
+            CancellationToken token = default)
+        {
+            if (request == null)
+                throw new ArgumentNullException(nameof(request));
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/server/lightning/{cryptoCode}/invoices", bodyPayload: request,
+                    method: HttpMethod.Post), token);
+            return await HandleResponse<LightningInvoiceData>(response);
+        }
+    }
+}

BTCPayServer.Client/BTCPayServerClient.Lightning.Store.cs

@@ -0,0 +1,148 @@
+using System;
+using System.Collections.Generic;
+using System.Net.Http;
+using System.Threading;
+using System.Threading.Tasks;
+using BTCPayServer.Client.Models;
+
+namespace BTCPayServer.Client
+{
+    public partial class BTCPayServerClient
+    {
+        public virtual async Task<LightningNodeInformationData> GetLightningNodeInfo(string storeId, string cryptoCode,
+            CancellationToken token = default)
+        {
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/stores/{storeId}/lightning/{cryptoCode}/info",
+                    method: HttpMethod.Get), token);
+            return await HandleResponse<LightningNodeInformationData>(response);
+        }
+
+        public virtual async Task<LightningNodeBalanceData> GetLightningNodeBalance(string storeId, string cryptoCode,
+            CancellationToken token = default)
+        {
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/stores/{storeId}/lightning/{cryptoCode}/balance",
+                    method: HttpMethod.Get), token);
+            return await HandleResponse<LightningNodeBalanceData>(response);
+        }
+
+        public virtual async Task ConnectToLightningNode(string storeId, string cryptoCode, ConnectToNodeRequest request,
+            CancellationToken token = default)
+        {
+            if (request == null)
+                throw new ArgumentNullException(nameof(request));
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/stores/{storeId}/lightning/{cryptoCode}/connect", bodyPayload: request,
+                    method: HttpMethod.Post), token);
+            await HandleResponse(response);
+        }
+
+        public virtual async Task<IEnumerable<LightningChannelData>> GetLightningNodeChannels(string storeId, string cryptoCode,
+            CancellationToken token = default)
+        {
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/stores/{storeId}/lightning/{cryptoCode}/channels",
+                    method: HttpMethod.Get), token);
+            return await HandleResponse<IEnumerable<LightningChannelData>>(response);
+        }
+
+        public virtual async Task OpenLightningChannel(string storeId, string cryptoCode, OpenLightningChannelRequest request,
+            CancellationToken token = default)
+        {
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/stores/{storeId}/lightning/{cryptoCode}/channels", bodyPayload: request,
+                    method: HttpMethod.Post), token);
+            await HandleResponse(response);
+        }
+
+        public virtual async Task<string> GetLightningDepositAddress(string storeId, string cryptoCode,
+            CancellationToken token = default)
+        {
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/stores/{storeId}/lightning/{cryptoCode}/address", method: HttpMethod.Post),
+                token);
+            return await HandleResponse<string>(response);
+        }
+
+        public virtual async Task<LightningPaymentData> PayLightningInvoice(string storeId, string cryptoCode, PayLightningInvoiceRequest request,
+            CancellationToken token = default)
+        {
+            if (request == null)
+                throw new ArgumentNullException(nameof(request));
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/stores/{storeId}/lightning/{cryptoCode}/invoices/pay", bodyPayload: request,
+                    method: HttpMethod.Post), token);
+            return await HandleResponse<LightningPaymentData>(response);
+        }
+
+        public virtual async Task<LightningPaymentData> GetLightningPayment(string storeId, string cryptoCode,
+            string paymentHash, CancellationToken token = default)
+        {
+            if (paymentHash == null)
+                throw new ArgumentNullException(nameof(paymentHash));
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/stores/{storeId}/lightning/{cryptoCode}/payments/{paymentHash}",
+                    method: HttpMethod.Get), token);
+            return await HandleResponse<LightningPaymentData>(response);
+        }
+
+        public virtual async Task<LightningInvoiceData> GetLightningInvoice(string storeId, string cryptoCode,
+            string invoiceId, CancellationToken token = default)
+        {
+            if (invoiceId == null)
+                throw new ArgumentNullException(nameof(invoiceId));
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/stores/{storeId}/lightning/{cryptoCode}/invoices/{invoiceId}",
+                    method: HttpMethod.Get), token);
+            return await HandleResponse<LightningInvoiceData>(response);
+        }
+
+        public virtual async Task<LightningInvoiceData[]> GetLightningInvoices(string storeId, string cryptoCode,
+            bool? pendingOnly = null, long? offsetIndex = null, CancellationToken token = default)
+        {
+            var queryPayload = new Dictionary<string, object>();
+            if (pendingOnly is bool v)
+            {
+                queryPayload.Add("pendingOnly", v.ToString());
+            }
+            if (offsetIndex is > 0)
+            {
+                queryPayload.Add("offsetIndex", offsetIndex);
+            }
+
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/stores/{storeId}/lightning/{cryptoCode}/invoices", queryPayload), token);
+            return await HandleResponse<LightningInvoiceData[]>(response);
+        }
+        
+        public virtual async Task<LightningPaymentData[]> GetLightningPayments(string storeId, string cryptoCode,
+            bool? includePending = null, long? offsetIndex = null, CancellationToken token = default)
+        {
+            var queryPayload = new Dictionary<string, object>();
+            if (includePending is bool v)
+            {
+                queryPayload.Add("includePending", v.ToString());
+            }
+            if (offsetIndex is > 0)
+            {
+                queryPayload.Add("offsetIndex", offsetIndex);
+            }
+
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/stores/{storeId}/lightning/{cryptoCode}/payments", queryPayload), token);
+            return await HandleResponse<LightningPaymentData[]>(response);
+        }
+
+        public virtual async Task<LightningInvoiceData> CreateLightningInvoice(string storeId, string cryptoCode,
+            CreateLightningInvoiceRequest request, CancellationToken token = default)
+        {
+            if (request == null)
+                throw new ArgumentNullException(nameof(request));
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/stores/{storeId}/lightning/{cryptoCode}/invoices", bodyPayload: request,
+                    method: HttpMethod.Post), token);
+            return await HandleResponse<LightningInvoiceData>(response);
+        }
+    }
+}

BTCPayServer.Client/BTCPayServerClient.LightningAddresses.cs

@@ -0,0 +1,48 @@
+using System.Net.Http;
+using System.Threading;
+using System.Threading.Tasks;
+using BTCPayServer.Client.Models;
+
+namespace BTCPayServer.Client
+{
+    public partial class BTCPayServerClient
+    {
+        public virtual async Task<LightningAddressData[]> GetStoreLightningAddresses(string storeId,
+            CancellationToken token = default)
+        {
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/stores/{storeId}/lightning-addresses",
+                    method: HttpMethod.Get), token);
+            return await HandleResponse<LightningAddressData[]>(response);
+        }
+
+        public virtual async Task<LightningAddressData> GetStoreLightningAddress(string storeId, string username,
+            CancellationToken token = default)
+        {
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/stores/{storeId}/lightning-addresses/{username}",
+                    method: HttpMethod.Get), token);
+            return await HandleResponse<LightningAddressData>(response);
+        }
+
+        public virtual async Task RemoveStoreLightningAddress(string storeId, string username,
+            CancellationToken token = default)
+        {
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/stores/{storeId}/lightning-addresses/{username}",
+                    method: HttpMethod.Delete), token);
+            await HandleResponse(response);
+        }
+
+        public virtual async Task<LightningAddressData> AddOrUpdateStoreLightningAddress(string storeId,
+            string username, LightningAddressData data,
+            CancellationToken token = default)
+        {
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/stores/{storeId}/lightning-addresses/{username}",
+                    method: HttpMethod.Post, bodyPayload: data), token);
+
+            return await HandleResponse<LightningAddressData>(response);
+        }
+    }
+}