Update Changelog and bump version

* Show correct array regardless of size

fixes #4890

* Email provided to pos form was not forwarded to form

fixes #4810

* Make invoice receipt url redirect to the invoice redirect url if receipt is not enabled

When setting up a default email rule upon invoice settlement, you would link to the receipt page naturally. However, if using the payment requests, receipts are disabled as the payment request itself is the receipt.  This commit makes the receipt url redirect to the invoice redirect url if available, and in the case of payment requests, it would mean the receipt url is the payment request url. fixes #4895

* Set the email address in the form when configured in the payment request

* fix pay request email copy

* fix payouts nav link

fixes #4788

* Update BTCPayServer/Views/UIPaymentRequest/EditPaymentRequest.cshtml

Co-authored-by: Nicolas Dorier <nicolas.dorier@gmail.com>

---------

Co-authored-by: Nicolas Dorier <nicolas.dorier@gmail.com>

.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

@@ -0,0 +1,154 @@
+version: 2
+jobs:
+  fast_tests:
+    machine:
+      image: ubuntu-2004:202111-02
+    steps:
+      - checkout
+      - run:
+          command: |
+            cd .circleci && ./run-tests.sh "Fast=Fast|ThirdParty=ThirdParty" && ./can-build.sh
+  selenium_tests:
+    machine:
+      image: ubuntu-2004:202111-02
+    steps:
+      - checkout
+      - run:
+          command: |
+            cd .circleci && ./run-tests.sh "Selenium=Selenium"
+  integration_tests:
+    machine:
+      image: ubuntu-2004:202111-02
+    steps:
+      - checkout
+      - run:
+          command: |
+            cd .circleci && ./run-tests.sh "Integration=Integration"
+  trigger_docs_build:
+    machine:
+      image: ubuntu-2004:202111-02
+    steps:
+      - run:
+          command: |
+            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, $DOCKERHUB_PASS defined
+  amd64:
+    machine:
+      image: ubuntu-2004:202111-02
+    steps:
+      - checkout
+      - run:
+          command: |
+            LATEST_TAG=${CIRCLE_TAG:1} #trim v from tag
+            GIT_COMMIT=$(git rev-parse HEAD)
+            #
+            sudo docker build --build-arg GIT_COMMIT=${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:
+      image: ubuntu-2004:202111-02
+    steps:
+      - 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 --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:
+      image: ubuntu-2004:202111-02
+    steps:
+      - 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 --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:
+      image: ubuntu-2004:202201-02
+    steps:
+      - run:
+          command: |
+            sudo docker login --username=$DOCKERHUB_USER --password=$DOCKERHUB_PASS
+            #
+            LATEST_TAG=${CIRCLE_TAG:1} #trim v from tag
+            sudo docker manifest create --amend $DOCKERHUB_REPO:$LATEST_TAG $DOCKERHUB_REPO:$LATEST_TAG-amd64 $DOCKERHUB_REPO:$LATEST_TAG-arm32v7 $DOCKERHUB_REPO:$LATEST_TAG-arm64v8
+            sudo docker manifest annotate $DOCKERHUB_REPO:$LATEST_TAG $DOCKERHUB_REPO:$LATEST_TAG-amd64 --os linux --arch amd64
+            sudo docker manifest annotate $DOCKERHUB_REPO:$LATEST_TAG $DOCKERHUB_REPO:$LATEST_TAG-arm32v7 --os linux --arch arm --variant v7
+            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:
+    jobs:
+      - fast_tests
+      - selenium_tests
+      - integration_tests
+  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 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]+)*(-[a-z0-9-]+)?)|(v[a-z0-9-]+)/
+      - arm32v7:
+          filters:
+            branches:
+              ignore: /.*/
+            tags:
+              only: /(v[1-9]+(\.[0-9]+)*(-[a-z0-9-]+)?)|(v[a-z0-9-]+)/
+      - arm64v8:
+          filters:
+            branches:
+              ignore: /.*/
+            tags:
+              only: /(v[1-9]+(\.[0-9]+)*(-[a-z0-9-]+)?)|(v[a-z0-9-]+)/
+      - multiarch:
+          requires:
+            - amd64
+            - arm32v7
+            - arm64v8
+          filters:
+            branches:
+              ignore: /.*/
+            tags:
+              only: /(v[1-9]+(\.[0-9]+)*(-[a-z0-9-]+)?)|(v[a-z0-9-]+)/

.circleci/run-tests.sh

@@ -0,0 +1,18 @@
+#!/bin/sh
+set -e
+
+cd ../BTCPayServer.Tests
+docker-compose -v
+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/FUNDING.yml

@@ -0,0 +1,2 @@
+# These are supported funding model platforms
+custom: https://foundation.btcpayserver.org

.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 +1,17 @@
+blank_issues_enabled: true
+contact_links:
+  - name: 💡 Request a feature
+    url: https://github.com/btcpayserver/btcpayserver/discussions/categories/ideas-feature-requests
+    about: Submit a feature request or vote on ideas posted by others. Features with most upvotes become roadmap candidates
+  - name: 🧑‍💻 Ask a technical question
+    url: https://github.com/btcpayserver/btcpayserver/discussions/new?category=technical-support
+    about: If you're experiencing a technical problem post it to our community support forum
+  - name: 🔌 Report a problem with a plugin
+    url: https://github.com/btcpayserver/btcpayserver/discussions/new?category=plugins-integrations
+    about: Experiencing a problem with a third-party plugin? Post it here and we will tag their developers to assist
+  - 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

.gitignore

@@ -288,8 +288,14 @@ __pycache__/
 *.xsd.cs
 /BTCPayServer/Build/dockerfiles
 
-# Bundling JS/CSS
-BTCPayServer/wwwroot/bundles/*
-!BTCPayServer/wwwroot/bundles/.gitignore
+.vscode/*
+!.vscode/launch.json
+!.vscode/tasks.json
+!.vscode/extensions.json
+BTCPayServer/testpwd
+.DS_Store
+Packed Plugins
+Plugins/packed
 
-.vscode
+BTCPayServer/wwwroot/swagger/v1/openapi.json
+BTCPayServer/appsettings.dev.json

.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

@@ -0,0 +1,11 @@
+namespace BTCPayServer.Abstractions.Constants
+{
+    public class AuthenticationSchemes
+    {
+        public const string Cookie = "Identity.Application";
+        public const string Bitpay = "Bitpay";
+        public const string Greenfield = "Greenfield.APIKeys,Greenfield.Basic";
+        public const string GreenfieldAPIKeys = "Greenfield.APIKeys";
+        public const string GreenfieldBasic = "Greenfield.Basic";
+    }
+}

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 +1,29 @@
+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 string Identifier { get; set; }
+        public string Type { 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

@@ -0,0 +1,10 @@
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace BTCPayServer.Abstractions.Contracts
+{
+    public interface IStartupTask
+    {
+        Task ExecuteAsync(CancellationToken cancellationToken = default);
+    }
+}

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 +1,12 @@
+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)
+    {
+    }
+
+    public AssetBalancesUnavailableException(string errorMsg) : base(500, "asset-balances-unavailable", $"Cannot fetch the asset balances: {errorMsg}")
+    {
+    }
+}

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/SimulateWithdrawalResult.cs

@@ -0,0 +1,28 @@
+using System.Collections.Generic;
+using BTCPayServer.Client.Models;
+using BTCPayServer.JsonConverters;
+
+namespace BTCPayServer.Abstractions.Custodians.Client;
+
+public class SimulateWithdrawalResult
+{
+    public string PaymentMethod { get; }
+    public string Asset { get; }
+    public decimal MinQty { get; }
+    public decimal MaxQty { get; }
+
+    public List<LedgerEntryData> LedgerEntries { get; }
+
+    // Fee can be NULL if unknown.
+    public decimal? Fee { get; }
+
+    public SimulateWithdrawalResult(string paymentMethod, string asset, List<LedgerEntryData> ledgerEntries,
+        decimal minQty, decimal maxQty)
+    {
+        PaymentMethod = paymentMethod;
+        Asset = asset;
+        LedgerEntries = ledgerEntries;
+        MinQty = minQty;
+        MaxQty = maxQty;
+    }
+}

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 +1,20 @@
+using System.Threading;
+using System.Threading.Tasks;
+using BTCPayServer.Abstractions.Custodians.Client;
+using Newtonsoft.Json.Linq;
+
+namespace BTCPayServer.Abstractions.Custodians;
+
+/// <summary>
+/// Interface for custodians that can move funds to the store wallet.
+/// </summary>
+public interface ICanWithdraw
+{
+    public Task<WithdrawResult> WithdrawToStoreWalletAsync(string paymentMethod, decimal amount, JObject config, CancellationToken cancellationToken);
+
+    public Task<SimulateWithdrawalResult> SimulateWithdrawalAsync(string paymentMethod, decimal qty, 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 @@
+#nullable enable
+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, 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 +1,47 @@
+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 UserNotFound(this ControllerBase ctrl)
+    {
+        return ctrl.CreateAPIError(404, "user-not-found", "The user was not found");
+    }
+    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 Constant;
+
+    // HTML5 compatible type string like "text", "textarea", "email", "password", etc.
+    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();
+
+    public virtual bool IsValid()
+    {
+        return ValidationErrors.Count == 0 && Fields.All(field => field.IsValid());
+    }
+}

BTCPayServer.Abstractions/Form/Form.cs

@@ -0,0 +1,141 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Reflection;
+using Microsoft.AspNetCore.Http;
+using Microsoft.Extensions.Primitives;
+using Newtonsoft.Json.Linq;
+using Npgsql.Internal.TypeHandlers.GeometricHandlers;
+
+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()
+    {
+        if (TopMessages?.Any(t => t.Type == AlertMessage.AlertMessageType.Danger) is true)
+            return false;
+        return Fields.Select(f => f.IsValid()).All(o => o);
+    }
+
+    public Field GetFieldByFullName(string fullName)
+    {
+        foreach (var f in GetAllFields())
+        {
+            if (f.FullName == fullName)
+                return f.Field;
+        }
+        return null;
+    }
+
+    public IEnumerable<(string FullName, List<string> Path, Field Field)> GetAllFields()
+    {
+        HashSet<string> nameReturned = new();
+        foreach (var f in GetAllFieldsCore(new List<string>(), Fields))
+        {
+            var fullName = string.Join('_', f.Path.Where(s => !string.IsNullOrEmpty(s)));
+            if (!nameReturned.Add(fullName))
+                continue;
+            yield return (fullName, f.Path, f.Field);
+        }
+    }
+
+    public bool ValidateFieldNames(out List<string> errors)
+    {
+        errors = new List<string>();
+        HashSet<string> nameReturned = new();
+        foreach (var f in GetAllFieldsCore(new List<string>(), Fields))
+        {
+            var fullName = string.Join('_', f.Path.Where(s => !string.IsNullOrEmpty(s)));
+            if (!nameReturned.Add(fullName))
+            {
+                errors.Add($"Form contains duplicate field names '{fullName}'");
+                continue;
+            }
+        }
+        return errors.Count == 0;
+    }
+
+    IEnumerable<(List<string> Path, Field Field)> GetAllFieldsCore(List<string> path, List<Field> fields)
+    {
+        foreach (var field in fields)
+        {
+            List<string> thisPath = new(path.Count + 1);
+            thisPath.AddRange(path);
+            if (!string.IsNullOrEmpty(field.Name))
+            {
+                thisPath.Add(field.Name);
+                yield return (thisPath, field);
+            }
+
+            foreach (var child in field.Fields)
+            {
+                if (field.Constant)
+                    child.Constant = true;
+                foreach (var descendant in GetAllFieldsCore(thisPath, field.Fields))
+                {
+                    yield return descendant;
+                }
+            }
+        }
+    }
+
+    public void ApplyValuesFromForm(IEnumerable<KeyValuePair<string, StringValues>> form)
+    {
+        var values = form.GroupBy(f => f.Key, f => f.Value).ToDictionary(g => g.Key, g => g.First());
+        foreach (var f in GetAllFields())
+        {
+            if (f.Field.Constant || !values.TryGetValue(f.FullName, out var val))
+                continue;
+
+            f.Field.Value = val;
+        }
+    }
+
+    public void SetValues(JObject values)
+    {
+        var fields = GetAllFields().ToDictionary(k => k.FullName, k => k.Field);
+        SetValues(fields, new List<string>(), values);
+    }
+
+    private void SetValues(Dictionary<string, Field> fields, List<string> path, JObject values)
+    {
+        foreach (var prop in values.Properties())
+        {
+            List<string> propPath = new List<string>(path.Count + 1);
+            propPath.AddRange(path);
+            propPath.Add(prop.Name);
+            if (prop.Value.Type == JTokenType.Object)
+            {
+                SetValues(fields, propPath, (JObject)prop.Value);
+            }
+            else if (prop.Value.Type == JTokenType.String)
+            {
+                var fullName = string.Join('_', propPath.Where(s => !string.IsNullOrEmpty(s)));
+                if (fields.TryGetValue(fullName, out var f) && !f.Constant)
+                    f.Value = prop.Value.Value<string>();
+            }
+        }
+    }
+
+
+}

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

@@ -0,0 +1,50 @@
+using System;
+
+namespace BTCPayServer.Abstractions.Models
+{
+    public class StatusMessageModel
+    {
+        public StatusMessageModel()
+        {
+        }
+        public string Message { get; set; }
+        public string Html { get; set; }
+        public StatusSeverity Severity { get; set; }
+        public bool AllowDismiss { get; set; } = true;
+
+        public string SeverityCSS => ToString(Severity);
+
+        private void ParseNonJsonStatus(string s)
+        {
+            Message = s;
+            Severity = s.StartsWith("Error", StringComparison.InvariantCultureIgnoreCase)
+                ? StatusSeverity.Error
+                : StatusSeverity.Success;
+        }
+
+        public static string ToString(StatusSeverity severity)
+        {
+            switch (severity)
+            {
+                case StatusSeverity.Info:
+                    return "info";
+                case StatusSeverity.Error:
+                    return "danger";
+                case StatusSeverity.Success:
+                    return "success";
+                case StatusSeverity.Warning:
+                    return "warning";
+                default:
+                    throw new ArgumentOutOfRangeException();
+            }
+        }
+
+        public enum StatusSeverity
+        {
+            Info,
+            Error,
+            Success,
+            Warning
+        }
+    }
+}

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;
         }
@@ -66,14 +68,57 @@ 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);
         }
 
+        public void UnsafeEval()
+        {
+            Add("script-src", "'unsafe-eval'");
+        }
+
         public IEnumerable<ConsentSecurityPolicy> Rules => _Policies;
         public bool HasRules => _Policies.Count != 0;
 
@@ -81,40 +126,25 @@ 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

@@ -0,0 +1,15 @@
+using System;
+using Microsoft.AspNetCore.Authorization;
+
+namespace BTCPayServer.Security
+{
+    public class PolicyRequirement : IAuthorizationRequirement
+    {
+        public PolicyRequirement(string 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

@@ -0,0 +1,30 @@
+using Ganss.XSS;
+using Microsoft.AspNetCore.Html;
+using Microsoft.AspNetCore.Mvc.Rendering;
+
+namespace BTCPayServer.Abstractions.Services
+{
+    public class Safe
+    {
+        private readonly IHtmlHelper _htmlHelper;
+        private readonly IJsonHelper _jsonHelper;
+        private readonly HtmlSanitizer _htmlSanitizer;
+
+        public Safe(IHtmlHelper htmlHelper, IJsonHelper jsonHelper, HtmlSanitizer htmlSanitizer)
+        {
+            _htmlHelper = htmlHelper;
+            _jsonHelper = jsonHelper;
+            _htmlSanitizer = htmlSanitizer;
+        }
+
+        public IHtmlContent Raw(string value)
+        {
+            return _htmlHelper.Raw(_htmlSanitizer.Sanitize(value));
+        }
+
+        public IHtmlContent Json(object model)
+        {
+            return _htmlHelper.Raw(_jsonHelper.Serialize(model));
+        }
+    }
+}

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 +1,42 @@
+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();
+        var symbolIndex = attr!.IndexOf("#", StringComparison.InvariantCulture);
+        var start = attr.IndexOf("~", StringComparison.InvariantCulture) + 1;
+        var length = (symbolIndex != -1 ? symbolIndex : attr.Length) - start;
+        var filePath = attr.Substring(start, length);
+        if (!string.IsNullOrEmpty(filePath))
+        {
+            var versioned = _fileVersionProvider.AddFileVersionToPath(ViewContext.HttpContext.Request.PathBase, filePath);
+            attr = attr.Replace(filePath, versioned);
+        }
+        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

@@ -0,0 +1,38 @@
+<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="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

@@ -0,0 +1,58 @@
+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<ApiKeyData> GetCurrentAPIKeyInfo(CancellationToken token = default)
+        {
+            var response = await _httpClient.SendAsync(CreateHttpRequest("api/v1/api-keys/current"), token);
+            return await HandleResponse<ApiKeyData>(response);
+        }
+
+        public virtual async Task<ApiKeyData> CreateAPIKey(CreateApiKeyRequest request, CancellationToken token = default)
+        {
+            if (request == null)
+                throw new ArgumentNullException(nameof(request));
+            var response = await _httpClient.SendAsync(CreateHttpRequest("api/v1/api-keys", bodyPayload: request, method: HttpMethod.Post), token);
+            return await HandleResponse<ApiKeyData>(response);
+        }
+
+        public virtual async Task<ApiKeyData> CreateAPIKey(string userId, CreateApiKeyRequest request, CancellationToken token = default)
+        {
+            if (request == null)
+                throw new ArgumentNullException(nameof(request));
+            var response = await _httpClient.SendAsync(CreateHttpRequest($"api/v1/users/{userId}/api-keys",
+            bodyPayload: request, method: HttpMethod.Post), token);
+            return await HandleResponse<ApiKeyData>(response);
+        }
+
+        public virtual async Task RevokeCurrentAPIKeyInfo(CancellationToken token = default)
+        {
+            var response = await _httpClient.SendAsync(CreateHttpRequest("api/v1/api-keys/current", null, HttpMethod.Delete), token);
+            await HandleResponse(response);
+        }
+
+        public virtual async Task RevokeAPIKey(string apikey, CancellationToken token = default)
+        {
+            if (apikey == null)
+                throw new ArgumentNullException(nameof(apikey));
+            var response = await _httpClient.SendAsync(CreateHttpRequest($"api/v1/api-keys/{apikey}", null, HttpMethod.Delete), token);
+            await HandleResponse(response);
+        }
+        public virtual async Task RevokeAPIKey(string userId, string apikey, CancellationToken token = default)
+        {
+            if (apikey == null)
+                throw new ArgumentNullException(nameof(apikey));
+            if (userId is null)
+                throw new ArgumentNullException(nameof(userId));
+            var response = await _httpClient.SendAsync(CreateHttpRequest($"api/v1/users/{userId}/api-keys/{apikey}", null, HttpMethod.Delete), token);
+            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

@@ -0,0 +1,34 @@
+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, (string ApplicationIdentifier, Uri Redirect) applicationDetails = default)
+        {
+            var result = new UriBuilder(btcpayHost);
+            result.Path = "api-keys/authorize";
+
+            AppendPayloadToQuery(result,
+                new Dictionary<string, object>()
+                {
+                    {"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 +1,102 @@
+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($"api/v1/stores/{storeId}/custodian-accounts/{accountId}", method: HttpMethod.Delete), token);
+            await HandleResponse(response);
+        }
+
+        public virtual async Task<DepositAddressData> GetCustodianAccountDepositAddress(string storeId, string accountId, string paymentMethod, CancellationToken token = default)
+        {
+            var response = await _httpClient.SendAsync(CreateHttpRequest($"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($"api/v1/stores/{storeId}/custodian-accounts/{accountId}/trades/market", null,
+                    request, HttpMethod.Post);
+            var response = await _httpClient.SendAsync(internalRequest, token);
+            return await HandleResponse<MarketTradeResponseData>(response);
+        }
+
+        public virtual async Task<MarketTradeResponseData> GetCustodianAccountTradeInfo(string storeId, string accountId, string tradeId, CancellationToken token = default)
+        {
+            var response = await _httpClient.SendAsync(CreateHttpRequest($"api/v1/stores/{storeId}/custodian-accounts/{accountId}/trades/{tradeId}", method: HttpMethod.Get), token);
+            return await HandleResponse<MarketTradeResponseData>(response);
+        }
+
+        public virtual async Task<TradeQuoteResponseData> GetCustodianAccountTradeQuote(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($"api/v1/stores/{storeId}/custodian-accounts/{accountId}/trades/quote", queryPayload), token);
+            return await HandleResponse<TradeQuoteResponseData>(response);
+        }
+
+        public virtual async Task<WithdrawalResponseData> CreateCustodianAccountWithdrawal(string storeId, string accountId, WithdrawRequestData request, CancellationToken token = default)
+        {
+            var response = await _httpClient.SendAsync(CreateHttpRequest($"api/v1/stores/{storeId}/custodian-accounts/{accountId}/withdrawals", bodyPayload: request, method: HttpMethod.Post), token);
+            return await HandleResponse<WithdrawalResponseData>(response);
+        }
+
+        public virtual async Task<WithdrawalSimulationResponseData> SimulateCustodianAccountWithdrawal(string storeId, string accountId, WithdrawRequestData request, CancellationToken token = default)
+        {
+            var response = await _httpClient.SendAsync(CreateHttpRequest($"api/v1/stores/{storeId}/custodian-accounts/{accountId}/withdrawals/simulation", bodyPayload: request, method: HttpMethod.Post), token);
+            return await HandleResponse<WithdrawalSimulationResponseData>(response);
+        }
+
+        public virtual async Task<WithdrawalResponseData> GetCustodianAccountWithdrawalInfo(string storeId, string accountId, string paymentMethod, string withdrawalId, CancellationToken token = default)
+        {
+            var response = await _httpClient.SendAsync(CreateHttpRequest($"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);
+        }
+    }
+}

BTCPayServer.Client/BTCPayServerClient.LightningNetworkPaymentMethods.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<LightningNetworkPaymentMethodData>>
+            GetStoreLightningNetworkPaymentMethods(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($"api/v1/stores/{storeId}/payment-methods/LightningNetwork",
+                        query), token);
+            return await HandleResponse<IEnumerable<LightningNetworkPaymentMethodData>>(response);
+        }
+
+        public virtual async Task<LightningNetworkPaymentMethodData> GetStoreLightningNetworkPaymentMethod(
+            string storeId,
+            string cryptoCode, CancellationToken token = default)
+        {
+            var response =
+                await _httpClient.SendAsync(
+                    CreateHttpRequest($"api/v1/stores/{storeId}/payment-methods/LightningNetwork/{cryptoCode}"), token);
+            return await HandleResponse<LightningNetworkPaymentMethodData>(response);
+        }
+
+        public virtual async Task RemoveStoreLightningNetworkPaymentMethod(string storeId,
+            string cryptoCode, CancellationToken token = default)
+        {
+            var response =
+                await _httpClient.SendAsync(
+                    CreateHttpRequest($"api/v1/stores/{storeId}/payment-methods/LightningNetwork/{cryptoCode}",
+                        method: HttpMethod.Delete), token);
+            await HandleResponse(response);
+        }
+
+        public virtual async Task<LightningNetworkPaymentMethodData> UpdateStoreLightningNetworkPaymentMethod(
+            string storeId,
+            string cryptoCode, UpdateLightningNetworkPaymentMethodRequest paymentMethod,
+            CancellationToken token = default)
+        {
+            var response = await _httpClient.SendAsync(
+                CreateHttpRequest($"api/v1/stores/{storeId}/payment-methods/LightningNetwork/{cryptoCode}",
+                    bodyPayload: paymentMethod, method: HttpMethod.Put), token);
+            return await HandleResponse<LightningNetworkPaymentMethodData>(response);
+        }
+    }
+}