fixes

BTCPayServer.Common/Altcoins/BTCPayNetworkProvider.Bitcoin.cs

@@ -24,6 +24,7 @@ namespace BTCPayServer
                 DefaultSettings = BTCPayDefaultSettings.GetDefaultSettings(NetworkType),
                 CoinType = NetworkType == NetworkType.Mainnet ? new KeyPath("0'") : new KeyPath("1'"),
                 SupportRBF = true,
+                BlockTime = TimeSpan.FromMinutes(10),
                 //https://github.com/spesmilo/electrum/blob/11733d6bc271646a00b69ff07657119598874da4/electrum/constants.py
                 ElectrumMapping = NetworkType == NetworkType.Mainnet
                     ? new Dictionary<uint, DerivationType>()

BTCPayServer.Common/Altcoins/BTCPayNetworkProvider.Dogecoin.cs

@@ -26,7 +26,8 @@ namespace BTCPayServer
                 },
                 CryptoImagePath = "imlegacy/dogecoin.png",
                 DefaultSettings = BTCPayDefaultSettings.GetDefaultSettings(NetworkType),
-                CoinType = NetworkType == NetworkType.Mainnet ? new KeyPath("3'") : new KeyPath("1'")
+                CoinType = NetworkType == NetworkType.Mainnet ? new KeyPath("3'") : new KeyPath("1'"),
+				BlockTime = TimeSpan.FromMinutes(2.5)
             });
         }
     }

BTCPayServer.Common/Altcoins/Liquid/BTCPayNetworkProvider.Liquid.cs

@@ -32,6 +32,7 @@ namespace BTCPayServer
                 DefaultSettings = BTCPayDefaultSettings.GetDefaultSettings(NetworkType),
                 CoinType = NetworkType == NetworkType.Mainnet ? new KeyPath("1776'") : new KeyPath("1'"),
                 SupportRBF = true,
+                BlockTime = TimeSpan.FromMinutes(1),
                 //https://github.com/spesmilo/electrum/blob/11733d6bc271646a00b69ff07657119598874da4/electrum/constants.py
                 ElectrumMapping = NetworkType == NetworkType.Mainnet
                     ? new Dictionary<uint, DerivationType>()

BTCPayServer.Common/Altcoins/Liquid/BTCPayNetworkProvider.LiquidAssets.cs

@@ -31,6 +31,7 @@ namespace BTCPayServer
                 DefaultSettings = BTCPayDefaultSettings.GetDefaultSettings(NetworkType),
                 CoinType = NetworkType == NetworkType.Mainnet ? new KeyPath("1776'") : new KeyPath("1'"),
                 SupportRBF = true,
+                BlockTime = TimeSpan.FromMinutes(1),
                 //https://github.com/spesmilo/electrum/blob/11733d6bc271646a00b69ff07657119598874da4/electrum/constants.py
                 ElectrumMapping = NetworkType == NetworkType.Mainnet
                     ? new Dictionary<uint, DerivationType>()

BTCPayServer.Common/BTCPayNetwork.cs

@@ -131,6 +131,18 @@ namespace BTCPayServer
 
         public string CryptoImagePath { get; set; }
         public string[] DefaultRateRules { get; internal set; } = Array.Empty<string>();
+        public TimeSpan? BlockTime { get; internal set; }
+
+        public TimeSpan GetTimeSpan(int blockCount)
+        {
+            return new TimeSpan(BlockTime.Value.Ticks * blockCount);
+        }
+
+        public int GetBlockCount(TimeSpan span)
+        {
+            return (int)Math.Round(((double)span.Ticks / BlockTime.Value.Ticks), MidpointRounding.ToEven);
+        }
+
         public override string ToString()
         {
             return CryptoCode;

BTCPayServer.Tests/BTCPayServerTester.cs

@@ -2,10 +2,7 @@
 using System.Linq;
 using BTCPayServer.HostedServices;
 using BTCPayServer.Hosting;
-using BTCPayServer.Payments;
-using BTCPayServer.Payments.Lightning;
 using BTCPayServer.Rating;
-using BTCPayServer.Security;
 using BTCPayServer.Services.Invoices;
 using BTCPayServer.Services.Rates;
 using BTCPayServer.Services.Stores;
@@ -14,27 +11,18 @@ using BTCPayServer.Tests.Mocks;
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Mvc;
-using Microsoft.AspNetCore.Mvc.Controllers;
-using Microsoft.AspNetCore.Mvc.Routing;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
 using NBitcoin;
 using NBXplorer;
-using NBXplorer.DerivationStrategy;
 using System;
 using System.Collections.Generic;
-using System.Diagnostics;
 using System.IO;
 using System.Net;
-using System.Net.Sockets;
-using System.Runtime.CompilerServices;
 using System.Security.Claims;
-using System.Security.Principal;
 using System.Text;
 using System.Threading;
 using OpenIddict.Abstractions;
-using Xunit;
-using BTCPayServer.Services;
 using System.Net.Http;
 using Microsoft.AspNetCore.Hosting.Server.Features;
 using System.Threading.Tasks;

BTCPayServer.Tests/ChangellyTests.cs

@@ -1,4 +1,3 @@
-using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Net.Http;
@@ -10,10 +9,8 @@ using BTCPayServer.Models.StoreViewModels;
 using BTCPayServer.Payments.Changelly;
 using BTCPayServer.Payments.Changelly.Models;
 using BTCPayServer.Services.Rates;
-using BTCPayServer.Services.Stores;
 using BTCPayServer.Tests.Logging;
 using Microsoft.AspNetCore.Mvc;
-using Microsoft.Extensions.Logging;
 using Xunit;
 using Xunit.Abstractions;
 

BTCPayServer.Tests/PaymentRequestTests.cs

@@ -1,26 +1,12 @@
 using System;
-using System.Collections.Generic;
 using System.Linq;
-using System.Net.Http;
-using System.Threading;
 using System.Threading.Tasks;
 using BTCPayServer.Controllers;
-using BTCPayServer.Data;
-using BTCPayServer.Events;
 using BTCPayServer.Models;
-using BTCPayServer.Models.AppViewModels;
 using BTCPayServer.Models.PaymentRequestViewModels;
-using BTCPayServer.Models.StoreViewModels;
-using BTCPayServer.Payments.Changelly;
-using BTCPayServer.Payments.Changelly.Models;
-using BTCPayServer.Services.Apps;
 using BTCPayServer.Services.Invoices;
-using BTCPayServer.Services.Rates;
-using BTCPayServer.Services.Stores;
 using BTCPayServer.Tests.Logging;
 using Microsoft.AspNetCore.Mvc;
-using Microsoft.Extensions.Logging;
-using NBitcoin;
 using NBitpayClient;
 using Xunit;
 using Xunit.Abstractions;

BTCPayServer.Tests/SeleniumTester.cs

@@ -1,26 +1,18 @@
 using System;
-using BTCPayServer;
 using System.Linq;
-using System.Collections.Generic;
-using System.Diagnostics;
 using System.Globalization;
 using System.Runtime.CompilerServices;
-using System.Text;
 using NBitcoin;
 using OpenQA.Selenium;
 using OpenQA.Selenium.Chrome;
 using Xunit;
 using System.IO;
-using System.Net.Http;
-using System.Reflection;
 using BTCPayServer.Tests.Logging;
 using System.Threading;
 using System.Threading.Tasks;
 using BTCPayServer.Lightning;
 using BTCPayServer.Lightning.CLightning;
 using BTCPayServer.Views.Stores;
-using Newtonsoft.Json;
-using Newtonsoft.Json.Linq;
 using OpenQA.Selenium.Interactions;
 
 namespace BTCPayServer.Tests

BTCPayServer.Tests/ServerTester.cs

@@ -1,28 +1,17 @@
-using BTCPayServer.Controllers;
-using System.Linq;
-using BTCPayServer.Models.AccountViewModels;
-using Microsoft.AspNetCore.Http;
-using Microsoft.AspNetCore.Mvc;
+using System.Linq;
 using NBitcoin;
 using NBitcoin.RPC;
 using NBitpayClient;
 using NBXplorer;
-using NBXplorer.Models;
 using System;
 using System.Collections.Generic;
-using System.Diagnostics;
 using System.IO;
 using System.Net.Http;
 using System.Runtime.CompilerServices;
-using System.Text;
 using System.Threading.Tasks;
-using System.Threading;
 using System.Globalization;
 using BTCPayServer.Tests.Lnd;
-using BTCPayServer.Payments.Lightning;
-using BTCPayServer.Lightning.CLightning;
 using BTCPayServer.Lightning;
-using BTCPayServer.Services;
 using BTCPayServer.Tests.Logging;
 
 namespace BTCPayServer.Tests

BTCPayServer.Tests/UnitTest1.cs

@@ -60,6 +60,7 @@ using Microsoft.Extensions.DependencyInjection;
 using NBXplorer.DerivationStrategy;
 using BTCPayServer.U2F.Models;
 using BTCPayServer.Security.Bitpay;
+using BTCPayServer.Views.Wallets;
 using MemoryCache = Microsoft.Extensions.Caching.Memory.MemoryCache;
 
 namespace BTCPayServer.Tests
@@ -1488,6 +1489,104 @@ namespace BTCPayServer.Tests
             }
         }
 
+        [Fact]
+        public async Task CanSwapCurrencies()
+        {
+            using (var tester = ServerTester.Create())
+            {
+                await tester.StartAsync();
+                var user = tester.NewAccount();
+                user.GrantAccess();
+                var userBTCWallet = user.RegisterDerivationScheme("BTC");
+                var userLTCWallet = user.RegisterDerivationScheme("LTC");
+                WalletId userBTCWallet2 = null;
+                WalletId userLTCWallet2 = null;
+                // For having faster test, let's create user2 concurrently
+                var creatingUser2 = Task.Run(() =>
+                {
+                    var u = tester.NewAccount();
+                    u.GrantAccess();
+                    userBTCWallet2 = u.RegisterDerivationScheme("BTC");
+                    userLTCWallet2 = u.RegisterDerivationScheme("LTC");
+                    return u;
+                });
+
+                
+
+                var atomics = user.GetController<WalletsController>();
+                var newXSwap = Assert.IsType<NewViewModel>(Assert.IsType<ViewResult>(atomics.NewAtomicSwap(userBTCWallet).Result).Model);
+                Assert.Equal(2, newXSwap.WalletList.Count());
+                Assert.Contains(userBTCWallet.ToString(), newXSwap.WalletList.Select(c => c.Value));
+                Assert.Contains(userLTCWallet.ToString(), newXSwap.WalletList.Select(c => c.Value));
+                newXSwap.Amount = 1.0;
+                newXSwap.Spread = 5;
+                newXSwap.RateRule = "coinaverage(BTC_USD) * coinaverage(USD_LTC);";
+                newXSwap.SelectedWallet = userLTCWallet.ToString();
+
+                Assert.IsType<RedirectToActionResult>(atomics.NewAtomicSwap(userBTCWallet, newXSwap).GetAwaiter().GetResult());
+                Assert.NotNull(atomics.CreatedOfferId);
+                var entry = atomics.AtomicSwapRepository.GetEntry(atomics.CreatedOfferId).Result;
+                Assert.NotNull(entry);
+                var offer = entry.Offer;
+                // The amount of BTC is less than the amount of LTC because it is more expensive
+                Assert.True(offer.Offer.Amount < offer.Price.Amount);
+                Assert.Equal("BTC", offer.Offer.CryptoCode);
+                Assert.Equal("LTC", offer.Price.CryptoCode);
+                Assert.Equal("coinaverage(BTC_USD) * coinaverage(USD_LTC)", offer.Rule);
+
+                // Let's check it the offer appear in the list
+                var list = Assert.IsType<ListViewModel>(Assert.IsType<ViewResult>(atomics.AtomicSwapList(userBTCWallet).Result).Model);
+                var item = list.Swaps[0];
+                Assert.Equal(XSwapRole.Maker.ToString(), item.Role);
+                Assert.Equal("1.00000000 BTC", item.Sent);
+                Assert.Equal("10.50000000 LTC", item.Received);
+                Assert.Equal(XSwapStatus.WaitingTaker.ToString(), item.Status);
+
+                // Let's get user2 take the offer
+                var user2 = creatingUser2.Result;
+                var apps2 = user2.GetController<AppsController>();
+
+                var atomics2 = user2.GetController<WalletsController>();
+                var takeVM = Assert.IsType<TakeViewModel>(Assert.IsType<ViewResult>(atomics2.TakeAtomicSwap(userBTCWallet2)).Model);
+                takeVM.MakerUri = atomics.AtomicSwapRepository.GetEntry(atomics.CreatedOfferId).Result.Offer.MarketMakerUri.ToString();
+
+                var list2 = Assert.IsType<ListViewModel>(Assert.IsType<ViewResult>(atomics2.AtomicSwapList(userBTCWallet2).Result).Model);
+                Assert.Empty(list2.Swaps);
+
+                atomics2.TakeAtomicSwap(userBTCWallet2, takeVM).Wait();
+
+                list = Assert.IsType<ListViewModel>(Assert.IsType<ViewResult>(atomics.AtomicSwapList(userBTCWallet).Result).Model);
+                list2 = Assert.IsType<ListViewModel>(Assert.IsType<ViewResult>(atomics2.AtomicSwapList(userBTCWallet2).Result).Model);
+
+                Assert.Single(list.Swaps);
+                Assert.Single(list2.Swaps);
+
+                Assert.Null(list.Swaps[0].Partner);
+                Assert.Equal("127.0.0.1", list2.Swaps[0].Partner);
+                Assert.Equal(XSwapStatus.WaitingTaker.ToString(), list.Swaps[0].Status);
+                Assert.Equal(XSwapStatus.WaitingTaker.ToString(), list2.Swaps[0].Status);
+
+                var takerVM = Assert.IsType<AtomicSwapDetailsTakerWaitingTakerViewModel>(Assert.IsType<ViewResult>(atomics2.AtomicSwapDetails(userBTCWallet2, atomics2.CreatedOfferId).Result).Model);
+
+                atomics2.AcceptAtomicSwapOffer(userBTCWallet2, atomics2.CreatedOfferId, takerVM).Wait();
+
+                list = Assert.IsType<ListViewModel>(Assert.IsType<ViewResult>(atomics.AtomicSwapList(userBTCWallet).Result).Model);
+                list2 = Assert.IsType<ListViewModel>(Assert.IsType<ViewResult>(atomics2.AtomicSwapList(userBTCWallet2).Result).Model);
+
+                Assert.Equal(XSwapStatus.WaitingEscrow.ToString(), list.Swaps[0].Status);
+                Assert.Equal(XSwapStatus.WaitingEscrow.ToString(), list2.Swaps[0].Status);
+                Assert.Equal(XSwapRole.Maker.ToString(), list.Swaps[0].Role);
+                Assert.Equal(XSwapRole.Taker.ToString(), list2.Swaps[0].Role);
+                Assert.Equal("1.00000000 BTC", list.Swaps[0].Sent);
+                Assert.Equal("10.50000000 LTC", list.Swaps[0].Received);
+                Assert.Equal("10.50000000 LTC", list2.Swaps[0].Sent);
+                Assert.Equal("1.00000000 BTC", list2.Swaps[0].Received);
+
+                var swapControler= Assert.IsType<AtomicSwapEscrowViewModel>(Assert.IsType<ViewResult>(atomics.AtomicSwapDetails(userBTCWallet, atomics.CreatedOfferId).Result).Model);
+            }
+        }
+
+
         [Fact(Timeout = TestTimeout)]
         [Trait("Integration", "Integration")]
         [Trait("Altcoins", "Altcoins")]

BTCPayServer/AtomicSwaps/AtomicSwapClient.cs

@@ -0,0 +1,130 @@
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+using System.Linq;
+using System.Net.Http;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+using BTCPayServer.Views.Wallets;
+using Microsoft.AspNetCore.Mvc.ModelBinding.Validation;
+using NBitcoin;
+using NBitcoin.JsonConverters;
+using NBXplorer;
+using Newtonsoft.Json;
+
+namespace BTCPayServer.AtomicSwaps
+{
+    public class AtomicSwapClient
+    {
+        public AtomicSwapClient(Uri serverAddress)
+        {
+            if (serverAddress == null)
+                throw new ArgumentNullException(nameof(serverAddress));
+            ServerAddress = serverAddress;
+        }
+
+        private static readonly HttpClient SharedClient = new HttpClient();
+        internal HttpClient Client = SharedClient;
+
+        public void SetClient(HttpClient client)
+        {
+            Client = client;
+        }
+        public Uri ServerAddress { get; }
+
+        internal string GetFullUri(string relativePath, params object[] parameters)
+        {
+            relativePath = string.Format(CultureInfo.InvariantCulture, relativePath, parameters ?? Array.Empty<object>());
+            var uri = ServerAddress.AbsoluteUri;
+            if (!uri.EndsWith("/", StringComparison.Ordinal))
+                uri += "/";
+            uri += relativePath;
+            return uri;
+        }
+        private Task<T> GetAsync<T>(string relativePath, object[] parameters, CancellationToken cancellation)
+        {
+            return SendAsync<T>(HttpMethod.Get, null, relativePath, parameters, cancellation);
+        }
+        private async Task<T> SendAsync<T>(HttpMethod method, object body, string relativePath, object[] parameters, CancellationToken cancellation)
+        {
+            HttpRequestMessage message = CreateMessage(method, body, relativePath, parameters);
+            var result = await Client.SendAsync(message, cancellation).ConfigureAwait(false);
+            if ((int)result.StatusCode == 404)
+            {
+                return default(T);
+            }
+            return await ParseResponse<T>(result).ConfigureAwait(false);
+        }
+
+        internal HttpRequestMessage CreateMessage(HttpMethod method, object body, string relativePath, object[] parameters)
+        {
+            var uri = GetFullUri(relativePath, parameters);
+            var message = new HttpRequestMessage(method, uri);
+            if (body != null)
+            {
+                if (body is byte[])
+                    message.Content = new ByteArrayContent((byte[])body);
+                else
+                    message.Content = new StringContent(NBitcoin.JsonConverters.Serializer.ToString(body), Encoding.UTF8, "application/json");
+            }
+
+            return message;
+        }
+
+        private async Task<T> ParseResponse<T>(HttpResponseMessage response)
+        {
+            using (response)
+            {
+                if (response.IsSuccessStatusCode)
+                    if (response.Content.Headers.ContentLength == 0)
+                        return default(T);
+                    else if (response.Content.Headers.ContentType.MediaType.Equals("application/json", StringComparison.Ordinal))
+                    {
+                        var str = await response.Content.ReadAsStringAsync().ConfigureAwait(false);
+                        return NBitcoin.JsonConverters.Serializer.ToObject<T>(str);
+                    }
+                    else if (response.Content.Headers.ContentType.MediaType.Equals("application/octet-stream", StringComparison.Ordinal))
+                    {
+                        return (T)(object)await response.Content.ReadAsByteArrayAsync().ConfigureAwait(false);
+                    }
+                if (response.StatusCode == System.Net.HttpStatusCode.NotFound)
+                    return default(T);
+                var aaa = await response.Content.ReadAsStringAsync().ConfigureAwait(false);
+                //if (response.StatusCode == System.Net.HttpStatusCode.InternalServerError)
+                response.EnsureSuccessStatusCode();
+                //var error = _Serializer.ToObject<NBXplorerError>(await response.Content.ReadAsStringAsync().ConfigureAwait(false));
+                //if (error == null)
+                //    response.EnsureSuccessStatusCode();
+                //throw error.AsException();
+                return default(T);
+            }
+        }
+
+        private Task ParseResponse(HttpResponseMessage response)
+        {
+            using (response)
+            {
+                if (response.IsSuccessStatusCode)
+                    return Task.CompletedTask;
+                //if (response.StatusCode == System.Net.HttpStatusCode.InternalServerError)
+                response.EnsureSuccessStatusCode();
+                //var error = _Serializer.ToObject<NBXplorerError>(await response.Content.ReadAsStringAsync().ConfigureAwait(false));
+                //if (error == null)
+                //    response.EnsureSuccessStatusCode();
+                //throw error.AsException();
+                return Task.CompletedTask;
+            }
+        }
+
+        internal async Task<AtomicSwapOffer> GetOffer(CancellationToken cancellation = default)
+        {
+            return await SendAsync<AtomicSwapOffer>(HttpMethod.Get, null, "offer", null, cancellation);
+        }
+
+        public async Task<AtomicSwapTakeResponse> Take(AtomicSwapTakeRequest atomicSwapTakeRequest, CancellationToken cancellation = default)
+        {
+            return await SendAsync<AtomicSwapTakeResponse>(HttpMethod.Post, atomicSwapTakeRequest, "take", null, cancellation);
+        }
+    }
+}

BTCPayServer/AtomicSwaps/AtomicSwapTakeRequest.cs

@@ -0,0 +1,17 @@
+using System;
+using NBitcoin;
+using NBitcoin.JsonConverters;
+using Newtonsoft.Json;
+
+namespace BTCPayServer.AtomicSwaps
+{
+    [Microsoft.AspNetCore.Mvc.ModelBinding.Validation.ValidateNeverAttribute]
+    public class AtomicSwapTakeRequest
+    {
+        [JsonConverter(typeof(KeyJsonConverter))]
+        public PubKey MakerSentCryptoPubkey { get; set; }
+        [JsonConverter(typeof(KeyJsonConverter))]
+        public PubKey MakerReceivedCryptoPubkey { get; set; }
+        public Uri TakerUri { get; set; }
+    }
+}

BTCPayServer/AtomicSwaps/AtomicSwapTakeResponse.cs

@@ -0,0 +1,16 @@
+using NBitcoin;
+using NBitcoin.JsonConverters;
+using Newtonsoft.Json;
+
+namespace BTCPayServer.AtomicSwaps
+{
+    public class AtomicSwapTakeResponse
+    {
+        [JsonConverter(typeof(UInt160JsonConverter))]
+        public uint160 Hash { get; set; }
+        [JsonConverter(typeof(KeyJsonConverter))]
+        public PubKey MakerSentCryptoPubkey { get; set; }
+        [JsonConverter(typeof(KeyJsonConverter))]
+        public PubKey MakerReceivedCryptoPubkey { get; set; }
+    }
+}

BTCPayServer/AtomicSwaps/Preimage.cs

@@ -0,0 +1,31 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using NBitcoin;
+using NBitcoin.Crypto;
+
+namespace BTCPayServer.AtomicSwaps
+{
+    public class Preimage
+    {
+        public Preimage()
+        {
+            Bytes = RandomUtils.GetBytes(32);
+        }
+        public Preimage(byte[] bytes)
+        {
+            Bytes = bytes;
+        }
+
+        public byte[] Bytes
+        {
+            get; set;
+        }
+
+        public uint160 GetHash()
+        {
+            return new uint160(Hashes.Hash160(Bytes, Bytes.Length));
+        }
+    }
+}

BTCPayServer/BTCPayServer.csproj

@@ -1,135 +1,135 @@
 <Project Sdk="Microsoft.NET.Sdk.Web">
-  <Import Project="../Build/Version.csproj" Condition="Exists('../Build/Version.csproj')" />
-  <Import Project="../Build/Common.csproj" />
-  
+  <Import Project="../Build/Version.csproj" Condition="Exists('../Build/Version.csproj')"/>
+  <Import Project="../Build/Common.csproj"/>
+
   <PropertyGroup>
     <OutputType>Exe</OutputType>
   </PropertyGroup>
   <ItemGroup>
-    <Compile Remove="Build\**" />
-    <Compile Remove="wwwroot\bundles\jqueryvalidate\**" />
-    <Compile Remove="wwwroot\vendor\jquery-nice-select\**" />
-    <Content Remove="Build\**" />
-    <Content Remove="wwwroot\bundles\jqueryvalidate\**" />
-    <Content Remove="wwwroot\vendor\jquery-nice-select\**" />
-    <EmbeddedResource Remove="Build\**" />
-    <EmbeddedResource Remove="wwwroot\bundles\jqueryvalidate\**" />
-    <EmbeddedResource Remove="wwwroot\vendor\jquery-nice-select\**" />
-    <None Remove="Build\**" />
-    <None Remove="wwwroot\bundles\jqueryvalidate\**" />
-    <None Remove="wwwroot\vendor\jquery-nice-select\**" />
+    <Compile Remove="Build\**"/>
+    <Compile Remove="wwwroot\bundles\jqueryvalidate\**"/>
+    <Compile Remove="wwwroot\vendor\jquery-nice-select\**"/>
+    <Content Remove="Build\**"/>
+    <Content Remove="wwwroot\bundles\jqueryvalidate\**"/>
+    <Content Remove="wwwroot\vendor\jquery-nice-select\**"/>
+    <EmbeddedResource Remove="Build\**"/>
+    <EmbeddedResource Remove="wwwroot\bundles\jqueryvalidate\**"/>
+    <EmbeddedResource Remove="wwwroot\vendor\jquery-nice-select\**"/>
+    <None Remove="Build\**"/>
+    <None Remove="wwwroot\bundles\jqueryvalidate\**"/>
+    <None Remove="wwwroot\vendor\jquery-nice-select\**"/>
   </ItemGroup>
   <ItemGroup>
-    <None Remove="Currencies.txt" />
+    <None Remove="Currencies.txt"/>
   </ItemGroup>
   <ItemGroup>
-    <EmbeddedResource Include="bundleconfig.json" />
-    <EmbeddedResource Include="Currencies.txt" />
+    <EmbeddedResource Include="bundleconfig.json"/>
+    <EmbeddedResource Include="Currencies.txt"/>
   </ItemGroup>
   <ItemGroup>
-    <PackageReference Include="BTCPayServer.Hwi" Version="1.1.3" />
-    <PackageReference Include="BTCPayServer.Lightning.All" Version="1.1.8" />
-    <PackageReference Include="BuildBundlerMinifier" Version="3.2.435" />
-    <PackageReference Include="BundlerMinifier.Core" Version="3.2.435" />
-    <PackageReference Include="BundlerMinifier.TagHelpers" Version="3.2.435" />
-    <PackageReference Include="HtmlSanitizer" Version="4.0.217" />
-    <PackageReference Include="LedgerWallet" Version="2.0.0.5" />
-    <PackageReference Include="Microsoft.Extensions.Logging.Filter" Version="1.1.2" />
+    <PackageReference Include="BTCPayServer.Hwi" Version="1.1.3"/>
+    <PackageReference Include="BTCPayServer.Lightning.All" Version="1.1.8"/>
+    <PackageReference Include="BuildBundlerMinifier" Version="3.2.435"/>
+    <PackageReference Include="BundlerMinifier.Core" Version="3.2.435"/>
+    <PackageReference Include="BundlerMinifier.TagHelpers" Version="3.2.435"/>
+    <PackageReference Include="HtmlSanitizer" Version="4.0.217"/>
+    <PackageReference Include="LedgerWallet" Version="2.0.0.5"/>
+    <PackageReference Include="Microsoft.Extensions.Logging.Filter" Version="1.1.2"/>
     <PackageReference Include="Microsoft.NetCore.Analyzers" Version="2.9.8">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets>
     </PackageReference>
-    <PackageReference Include="NBitpayClient" Version="1.0.0.35" />	  
-    <PackageReference Include="DBriize" Version="1.0.1.3" />
-    <PackageReference Include="Newtonsoft.Json" Version="12.0.3" />
-    <PackageReference Include="NicolasDorier.CommandLine" Version="1.0.0.2" />
-    <PackageReference Include="NicolasDorier.CommandLine.Configuration" Version="1.0.0.3" />
-    <PackageReference Include="NicolasDorier.RateLimits" Version="1.1.0" />
-    <PackageReference Include="NicolasDorier.StandardConfiguration" Version="1.0.0.18" />
-    <PackageReference Include="Serilog" Version="2.9.0" />
-    <PackageReference Include="Serilog.AspNetCore" Version="3.2.0" />
-    <PackageReference Include="Serilog.Sinks.File" Version="4.1.0" />
-    <PackageReference Include="SSH.NET" Version="2016.1.0" />
+    <PackageReference Include="NBitpayClient" Version="1.0.0.35"/>
+    <PackageReference Include="DBriize" Version="1.0.1.3"/>
+    <PackageReference Include="Newtonsoft.Json" Version="12.0.3"/>
+    <PackageReference Include="NicolasDorier.CommandLine" Version="1.0.0.2"/>
+    <PackageReference Include="NicolasDorier.CommandLine.Configuration" Version="1.0.0.3"/>
+    <PackageReference Include="NicolasDorier.RateLimits" Version="1.1.0"/>
+    <PackageReference Include="NicolasDorier.StandardConfiguration" Version="1.0.0.18"/>
+    <PackageReference Include="Serilog" Version="2.9.0"/>
+    <PackageReference Include="Serilog.AspNetCore" Version="3.2.0"/>
+    <PackageReference Include="Serilog.Sinks.File" Version="4.1.0"/>
+    <PackageReference Include="SSH.NET" Version="2016.1.0"/>
     <PackageReference Include="Text.Analyzers" Version="2.6.4">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets>
     </PackageReference>
   </ItemGroup>
 
-	<ItemGroup>
-    <PackageReference Include="TwentyTwenty.Storage" Version="2.12.1" />
-    <PackageReference Include="TwentyTwenty.Storage.Amazon" Version="2.12.1" />
-    <PackageReference Include="TwentyTwenty.Storage.Azure" Version="2.12.1" />
-    <PackageReference Include="TwentyTwenty.Storage.Google" Version="2.12.1" />
-    <PackageReference Include="TwentyTwenty.Storage.Local" Version="2.12.1" />
-    <PackageReference Include="U2F.Core" Version="1.0.4" />
-		<PackageReference Include="YamlDotNet" Version="8.0.0" />
-    <PackageReference Include="OpenIddict" Version="3.0.0-alpha1.20058.15" />
+  <ItemGroup>
+    <PackageReference Include="TwentyTwenty.Storage" Version="2.12.1"/>
+    <PackageReference Include="TwentyTwenty.Storage.Amazon" Version="2.12.1"/>
+    <PackageReference Include="TwentyTwenty.Storage.Azure" Version="2.12.1"/>
+    <PackageReference Include="TwentyTwenty.Storage.Google" Version="2.12.1"/>
+    <PackageReference Include="TwentyTwenty.Storage.Local" Version="2.12.1"/>
+    <PackageReference Include="U2F.Core" Version="1.0.4"/>
+    <PackageReference Include="YamlDotNet" Version="8.0.0"/>
+    <PackageReference Include="OpenIddict" Version="3.0.0-alpha1.20058.15"/>
     <PackageReference Include="OpenIddict.Server.AspNetCore" Version="3.0.0-alpha1.20058.15"></PackageReference>
     <PackageReference Include="OpenIddict.Validation.AspNetCore" Version="3.0.0-alpha1.20058.15"></PackageReference>
-    <PackageReference Include="Microsoft.AspNetCore.Mvc.Razor.RuntimeCompilation" Version="3.1.0" Condition="'$(Configuration)' == 'Debug'" />
-    <PackageReference Include="Microsoft.AspNetCore.Mvc.NewtonsoftJson" Version="3.1.0" />
+    <PackageReference Include="Microsoft.AspNetCore.Mvc.Razor.RuntimeCompilation" Version="3.1.0" Condition="'$(Configuration)' == 'Debug'"/>
+    <PackageReference Include="Microsoft.AspNetCore.Mvc.NewtonsoftJson" Version="3.1.0"/>
   </ItemGroup>
 
-	<ItemGroup>
-	  <None Include="wwwroot\main\bootstrap4-creativestart\creative.js" />
-	  <None Include="wwwroot\vendor\font-awesome\fonts\fontawesome-webfont.svg" />
-	  <None Include="wwwroot\vendor\font-awesome\fonts\fontawesome-webfont.woff2" />
-	  <None Include="wwwroot\vendor\font-awesome\less\animated.less" />
-	  <None Include="wwwroot\vendor\font-awesome\less\bordered-pulled.less" />
-	  <None Include="wwwroot\vendor\font-awesome\less\core.less" />
-	  <None Include="wwwroot\vendor\font-awesome\less\fixed-width.less" />
-	  <None Include="wwwroot\vendor\font-awesome\less\font-awesome.less" />
-	  <None Include="wwwroot\vendor\font-awesome\less\icons.less" />
-	  <None Include="wwwroot\vendor\font-awesome\less\larger.less" />
-	  <None Include="wwwroot\vendor\font-awesome\less\list.less" />
-	  <None Include="wwwroot\vendor\font-awesome\less\mixins.less" />
-	  <None Include="wwwroot\vendor\font-awesome\less\path.less" />
-	  <None Include="wwwroot\vendor\font-awesome\less\rotated-flipped.less" />
-	  <None Include="wwwroot\vendor\font-awesome\less\screen-reader.less" />
-	  <None Include="wwwroot\vendor\font-awesome\less\stacked.less" />
-	  <None Include="wwwroot\vendor\font-awesome\less\variables.less" />
-	  <None Include="wwwroot\vendor\font-awesome\scss\font-awesome.scss" />
-	  <None Include="wwwroot\vendor\font-awesome\scss\_animated.scss" />
-	  <None Include="wwwroot\vendor\font-awesome\scss\_bordered-pulled.scss" />
-	  <None Include="wwwroot\vendor\font-awesome\scss\_core.scss" />
-	  <None Include="wwwroot\vendor\font-awesome\scss\_fixed-width.scss" />
-	  <None Include="wwwroot\vendor\font-awesome\scss\_icons.scss" />
-	  <None Include="wwwroot\vendor\font-awesome\scss\_larger.scss" />
-	  <None Include="wwwroot\vendor\font-awesome\scss\_list.scss" />
-	  <None Include="wwwroot\vendor\font-awesome\scss\_mixins.scss" />
-	  <None Include="wwwroot\vendor\font-awesome\scss\_path.scss" />
-	  <None Include="wwwroot\vendor\font-awesome\scss\_rotated-flipped.scss" />
-	  <None Include="wwwroot\vendor\font-awesome\scss\_screen-reader.scss" />
-	  <None Include="wwwroot\vendor\font-awesome\scss\_stacked.scss" />
-	  <None Include="wwwroot\vendor\font-awesome\scss\_variables.scss" />
-	  <None Include="wwwroot\vendor\jquery-easing\jquery.easing.compatibility.js" />
-	  <None Include="wwwroot\vendor\jquery-easing\jquery.easing.js" />
-	  <None Include="wwwroot\vendor\jquery-easing\jquery.easing.min.js" />
-	  <None Include="wwwroot\vendor\jquery\jquery.js" />
-	  <None Include="wwwroot\vendor\jquery\jquery.min.js" />
-	  <None Include="wwwroot\vendor\magnific-popup\jquery.magnific-popup.js" />
-	  <None Include="wwwroot\vendor\magnific-popup\jquery.magnific-popup.min.js" />
-	  <None Include="wwwroot\vendor\popper\popper.js" />
-	  <None Include="wwwroot\vendor\popper\popper.min.js" />
-	  <None Include="wwwroot\vendor\scrollreveal\scrollreveal.js" />
-	  <None Include="wwwroot\vendor\scrollreveal\scrollreveal.min.js" />
-	</ItemGroup>
+  <ItemGroup>
+    <None Include="wwwroot\main\bootstrap4-creativestart\creative.js"/>
+    <None Include="wwwroot\vendor\font-awesome\fonts\fontawesome-webfont.svg"/>
+    <None Include="wwwroot\vendor\font-awesome\fonts\fontawesome-webfont.woff2"/>
+    <None Include="wwwroot\vendor\font-awesome\less\animated.less"/>
+    <None Include="wwwroot\vendor\font-awesome\less\bordered-pulled.less"/>
+    <None Include="wwwroot\vendor\font-awesome\less\core.less"/>
+    <None Include="wwwroot\vendor\font-awesome\less\fixed-width.less"/>
+    <None Include="wwwroot\vendor\font-awesome\less\font-awesome.less"/>
+    <None Include="wwwroot\vendor\font-awesome\less\icons.less"/>
+    <None Include="wwwroot\vendor\font-awesome\less\larger.less"/>
+    <None Include="wwwroot\vendor\font-awesome\less\list.less"/>
+    <None Include="wwwroot\vendor\font-awesome\less\mixins.less"/>
+    <None Include="wwwroot\vendor\font-awesome\less\path.less"/>
+    <None Include="wwwroot\vendor\font-awesome\less\rotated-flipped.less"/>
+    <None Include="wwwroot\vendor\font-awesome\less\screen-reader.less"/>
+    <None Include="wwwroot\vendor\font-awesome\less\stacked.less"/>
+    <None Include="wwwroot\vendor\font-awesome\less\variables.less"/>
+    <None Include="wwwroot\vendor\font-awesome\scss\font-awesome.scss"/>
+    <None Include="wwwroot\vendor\font-awesome\scss\_animated.scss"/>
+    <None Include="wwwroot\vendor\font-awesome\scss\_bordered-pulled.scss"/>
+    <None Include="wwwroot\vendor\font-awesome\scss\_core.scss"/>
+    <None Include="wwwroot\vendor\font-awesome\scss\_fixed-width.scss"/>
+    <None Include="wwwroot\vendor\font-awesome\scss\_icons.scss"/>
+    <None Include="wwwroot\vendor\font-awesome\scss\_larger.scss"/>
+    <None Include="wwwroot\vendor\font-awesome\scss\_list.scss"/>
+    <None Include="wwwroot\vendor\font-awesome\scss\_mixins.scss"/>
+    <None Include="wwwroot\vendor\font-awesome\scss\_path.scss"/>
+    <None Include="wwwroot\vendor\font-awesome\scss\_rotated-flipped.scss"/>
+    <None Include="wwwroot\vendor\font-awesome\scss\_screen-reader.scss"/>
+    <None Include="wwwroot\vendor\font-awesome\scss\_stacked.scss"/>
+    <None Include="wwwroot\vendor\font-awesome\scss\_variables.scss"/>
+    <None Include="wwwroot\vendor\jquery-easing\jquery.easing.compatibility.js"/>
+    <None Include="wwwroot\vendor\jquery-easing\jquery.easing.js"/>
+    <None Include="wwwroot\vendor\jquery-easing\jquery.easing.min.js"/>
+    <None Include="wwwroot\vendor\jquery\jquery.js"/>
+    <None Include="wwwroot\vendor\jquery\jquery.min.js"/>
+    <None Include="wwwroot\vendor\magnific-popup\jquery.magnific-popup.js"/>
+    <None Include="wwwroot\vendor\magnific-popup\jquery.magnific-popup.min.js"/>
+    <None Include="wwwroot\vendor\popper\popper.js"/>
+    <None Include="wwwroot\vendor\popper\popper.min.js"/>
+    <None Include="wwwroot\vendor\scrollreveal\scrollreveal.js"/>
+    <None Include="wwwroot\vendor\scrollreveal\scrollreveal.min.js"/>
+  </ItemGroup>
 
-	<ItemGroup>
-	  <Folder Include="wwwroot\vendor\clipboard.js\" />
-	  <Folder Include="wwwroot\vendor\highlightjs\" />
-	  <Folder Include="wwwroot\vendor\summernote" />
-	  <Folder Include="wwwroot\vendor\u2f" />
-	</ItemGroup>
+  <ItemGroup>
+    <Folder Include="wwwroot\vendor\clipboard.js\"/>
+    <Folder Include="wwwroot\vendor\highlightjs\"/>
+    <Folder Include="wwwroot\vendor\summernote"/>
+    <Folder Include="wwwroot\vendor\u2f"/>
+  </ItemGroup>
 
-	<ItemGroup>
-	  <ProjectReference Include="..\BTCPayServer.Data\BTCPayServer.Data.csproj" />
-	  <ProjectReference Include="..\BTCPayServer.Rating\BTCPayServer.Rating.csproj" />
-	  <ProjectReference Include="..\BTCPayServer.Common\BTCPayServer.Common.csproj" />
-	</ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\BTCPayServer.Data\BTCPayServer.Data.csproj"/>
+    <ProjectReference Include="..\BTCPayServer.Rating\BTCPayServer.Rating.csproj"/>
+    <ProjectReference Include="..\BTCPayServer.Common\BTCPayServer.Common.csproj"/>
+  </ItemGroup>
 
-	<ItemGroup>
+  <ItemGroup>
     <Content Update="Views\Apps\_ViewImports.cshtml">
       <CopyToPublishDirectory>PreserveNewest</CopyToPublishDirectory>
       <Pack>$(IncludeRazorContentInPack)</Pack>
@@ -158,6 +158,27 @@
     <Content Update="Views\Server\DynamicDnsService.cshtml">
       <Pack>$(IncludeRazorContentInPack)</Pack>
     </Content>
+    <Content Update="Views\Wallets\AtomicSwapDetailsMarkerWaitingTaker.cshtml">
+      <Pack>$(IncludeRazorContentInPack)</Pack>
+    </Content>
+    <Content Update="Views\Wallets\AtomicSwapEscrow.cshtml">
+      <Pack>$(IncludeRazorContentInPack)</Pack>
+    </Content>
+    <Content Update="Views\Wallets\AtomicSwapDetailsTakerWaitingTaker.cshtml">
+      <Pack>$(IncludeRazorContentInPack)</Pack>
+    </Content>
+    <Content Update="Views\Wallets\AtomicSwapDetails.cshtml">
+      <Pack>$(IncludeRazorContentInPack)</Pack>
+    </Content>
+    <Content Update="Views\Wallets\TakeAtomicSwap.cshtml">
+      <Pack>$(IncludeRazorContentInPack)</Pack>
+    </Content>
+    <Content Update="Views\Wallets\NewAtomicSwap.cshtml">
+      <Pack>$(IncludeRazorContentInPack)</Pack>
+    </Content>
+    <Content Update="Views\Wallets\AtomicSwapList.cshtml">
+      <Pack>$(IncludeRazorContentInPack)</Pack>
+    </Content>
     <Content Update="Views\Server\SSHService.cshtml">
       <Pack>$(IncludeRazorContentInPack)</Pack>
     </Content>
@@ -167,55 +188,55 @@
     <Content Update="Views\Stores\PayButtonEnable.cshtml">
       <Pack>$(IncludeRazorContentInPack)</Pack>
     </Content>
-	  <Content Update="Views\Stores\PayButton.cshtml">
-	    <Pack>$(IncludeRazorContentInPack)</Pack>
-	  </Content>
-	  <Content Update="Views\Public\PayButtonHandle.cshtml">
-	    <Pack>$(IncludeRazorContentInPack)</Pack>
-	  </Content>
-	  <Content Update="Views\Server\LndServices.cshtml">
-	    <Pack>$(IncludeRazorContentInPack)</Pack>
-	  </Content>
-	  <Content Update="Views\Server\Maintenance.cshtml">
-	    <Pack>$(IncludeRazorContentInPack)</Pack>
-	  </Content>
-	  <Content Update="Views\Server\Services.cshtml">
-	    <Pack>$(IncludeRazorContentInPack)</Pack>
-	  </Content>
-	  <Content Update="Views\Wallets\ListWallets.cshtml">
-	    <Pack>$(IncludeRazorContentInPack)</Pack>
-	  </Content>
-	  <Content Update="Views\Wallets\WalletPSBTCombine.cshtml">
-	    <Pack>$(IncludeRazorContentInPack)</Pack>
-	  </Content>
-	  <Content Update="Views\Wallets\WalletPSBTReady.cshtml">
-	    <Pack>$(IncludeRazorContentInPack)</Pack>
-	  </Content>
-	  <Content Update="Views\Wallets\WalletPSBT.cshtml">
-	    <Pack>$(IncludeRazorContentInPack)</Pack>
-	  </Content>
-	  <Content Update="Views\Wallets\WalletRescan.cshtml">
-	    <Pack>$(IncludeRazorContentInPack)</Pack>
-	  </Content>
-	  <Content Update="Views\Wallets\WalletSendVault.cshtml">
-	    <Pack>$(IncludeRazorContentInPack)</Pack>
-	  </Content>
-	  <Content Update="Views\Wallets\WalletSendLedger.cshtml">
-	    <Pack>$(IncludeRazorContentInPack)</Pack>
-	  </Content>
-	  <Content Update="Views\Wallets\WalletTransactions.cshtml">
-	    <Pack>$(IncludeRazorContentInPack)</Pack>
-	  </Content>
+    <Content Update="Views\Stores\PayButton.cshtml">
+      <Pack>$(IncludeRazorContentInPack)</Pack>
+    </Content>
+    <Content Update="Views\Public\PayButtonHandle.cshtml">
+      <Pack>$(IncludeRazorContentInPack)</Pack>
+    </Content>
+    <Content Update="Views\Server\LndServices.cshtml">
+      <Pack>$(IncludeRazorContentInPack)</Pack>
+    </Content>
+    <Content Update="Views\Server\Maintenance.cshtml">
+      <Pack>$(IncludeRazorContentInPack)</Pack>
+    </Content>
+    <Content Update="Views\Server\Services.cshtml">
+      <Pack>$(IncludeRazorContentInPack)</Pack>
+    </Content>
+    <Content Update="Views\Wallets\ListWallets.cshtml">
+      <Pack>$(IncludeRazorContentInPack)</Pack>
+    </Content>
+    <Content Update="Views\Wallets\WalletPSBTCombine.cshtml">
+      <Pack>$(IncludeRazorContentInPack)</Pack>
+    </Content>
+    <Content Update="Views\Wallets\WalletPSBTReady.cshtml">
+      <Pack>$(IncludeRazorContentInPack)</Pack>
+    </Content>
+    <Content Update="Views\Wallets\WalletPSBT.cshtml">
+      <Pack>$(IncludeRazorContentInPack)</Pack>
+    </Content>
+    <Content Update="Views\Wallets\WalletRescan.cshtml">
+      <Pack>$(IncludeRazorContentInPack)</Pack>
+    </Content>
+    <Content Update="Views\Wallets\WalletSendVault.cshtml">
+      <Pack>$(IncludeRazorContentInPack)</Pack>
+    </Content>
+    <Content Update="Views\Wallets\WalletSendLedger.cshtml">
+      <Pack>$(IncludeRazorContentInPack)</Pack>
+    </Content>
+    <Content Update="Views\Wallets\WalletTransactions.cshtml">
+      <Pack>$(IncludeRazorContentInPack)</Pack>
+    </Content>
     <Content Remove="Views\Server\EditGoogleCloudStorageStorageProvider.cshtml">
     </Content>
-	  <Content Update="Views\Wallets\_Nav.cshtml">
-	    <Pack>$(IncludeRazorContentInPack)</Pack>
-	  </Content>
-	  <Content Update="Views\Wallets\_ViewImports.cshtml">
-	    <Pack>$(IncludeRazorContentInPack)</Pack>
-	  </Content>
-	  <Content Update="Views\Wallets\_ViewStart.cshtml">
-	    <Pack>$(IncludeRazorContentInPack)</Pack>
-	  </Content>
-	</ItemGroup>
+    <Content Update="Views\Wallets\_Nav.cshtml">
+      <Pack>$(IncludeRazorContentInPack)</Pack>
+    </Content>
+    <Content Update="Views\Wallets\_ViewImports.cshtml">
+      <Pack>$(IncludeRazorContentInPack)</Pack>
+    </Content>
+    <Content Update="Views\Wallets\_ViewStart.cshtml">
+      <Pack>$(IncludeRazorContentInPack)</Pack>
+    </Content>
+  </ItemGroup>
 </Project>

BTCPayServer/Controllers/AtomicSwapController.cs

@@ -0,0 +1,97 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Net.Http;
+using System.Threading;
+using System.Threading.Tasks;
+using BTCPayServer.AtomicSwaps;
+using BTCPayServer.Data;
+using BTCPayServer.Models;
+using BTCPayServer.Payments;
+using BTCPayServer.Payments.Bitcoin;
+using BTCPayServer.Rating;
+using BTCPayServer.Services;
+using BTCPayServer.Services.Apps;
+using BTCPayServer.Services.Rates;
+using BTCPayServer.Services.Stores;
+using BTCPayServer.Views.Wallets;
+using Microsoft.AspNetCore.Identity;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.AspNetCore.Mvc.ModelBinding.Validation;
+using NBitcoin;
+using NBitcoin.Crypto;
+using NBitcoin.DataEncoders;
+using NBitcoin.JsonConverters;
+using Newtonsoft.Json;
+
+
+namespace BTCPayServer.Controllers
+{
+    [Route("api/xswap")]
+    public partial class AtomicSwapController : Controller
+    {
+        public AtomicSwapController(AtomicSwapRepository atomicSwapRepository, AtomicSwapClientFactory atomicSwapClientFactory)
+        {
+            AtomicSwapRepository = atomicSwapRepository;
+            AtomicSwapClientFactory = atomicSwapClientFactory;
+        }
+
+        public AtomicSwapRepository AtomicSwapRepository { get; }
+        public AtomicSwapClientFactory AtomicSwapClientFactory { get; }
+
+        [Route("{offerId}/offer")]
+        public async Task<IActionResult> GetOfferAPI(string offerId)
+        {
+            var entry = await AtomicSwapRepository.GetEntry(offerId);
+            if (entry == null ||
+                (entry.Status != XSwapStatus.WaitingTaker && entry.Role == XSwapRole.Maker) ||
+                (entry.Status != XSwapStatus.WaitingEscrow && entry.Role == XSwapRole.Taker))
+                return NotFound();
+            return Json(entry.Offer);
+        }
+
+        [Route("{offerId}/take")]
+        [HttpPost]
+        [IgnoreAntiforgeryToken]
+        public async Task<IActionResult> TakeOfferAPI(string offerId, [FromBody] AtomicSwapTakeRequest request)
+        {
+            var entry = await AtomicSwapRepository.GetEntry(offerId);
+            if (entry == null || entry.Status != XSwapStatus.WaitingTaker)
+                return NotFound();
+            // TODO atomically take the offer
+            var client = AtomicSwapClientFactory.Create(request.TakerUri);
+            AtomicSwapTakeResponse response = null;
+            try
+            {
+                using (var cts = new CancellationTokenSource())
+                {
+                    cts.CancelAfter(5000);
+                    var takerOffer = await client.GetOffer(cts.Token);
+                    if (takerOffer.MarketMakerUri != entry.Offer.MarketMakerUri)
+                        return NotFound();
+                }
+            }
+            catch { }
+
+            entry.Partner = request.TakerUri.DnsSafeHost;
+            entry.OtherUri = request.TakerUri;
+            entry.Status = XSwapStatus.WaitingEscrow;
+            entry.Sent.MyKey = new Key();
+            entry.Sent.OtherKey = request.MakerSentCryptoPubkey;
+            entry.Received.MyKey = new Key();
+            entry.Received.OtherKey = request.MakerReceivedCryptoPubkey;
+            entry.Preimage = new Preimage();
+            entry.Hash = entry.Preimage.GetHash();
+
+            response = new AtomicSwapTakeResponse()
+            {
+                Hash = entry.Preimage.GetHash(),
+                MakerReceivedCryptoPubkey = entry.Received.MyKey.PubKey,
+                MakerSentCryptoPubkey = entry.Received.MyKey.PubKey
+            };
+
+            await AtomicSwapRepository.UpdateEntry(offerId, entry);
+            return Json(response);
+        }
+    }
+}

BTCPayServer/Controllers/WalletsController.cs

@@ -3,6 +3,7 @@ using System.Collections.Generic;
 using System.ComponentModel.DataAnnotations;
 using System.Globalization;
 using System.Linq;
+using System.Net.Http;
 using System.Net.WebSockets;
 using System.Text;
 using System.Threading;
@@ -17,6 +18,7 @@ using BTCPayServer.Services;
 using BTCPayServer.Services.Rates;
 using BTCPayServer.Services.Stores;
 using BTCPayServer.Services.Wallets;
+using BTCPayServer.Views.Wallets;
 using LedgerWallet;
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Http;
@@ -40,8 +42,10 @@ namespace BTCPayServer.Controllers
     {
         public StoreRepository Repository { get; }
         public WalletRepository WalletRepository { get; }
+        public AtomicSwapRepository AtomicSwapRepository { get; }
         public BTCPayNetworkProvider NetworkProvider { get; }
         public ExplorerClientProvider ExplorerClientProvider { get; }
+        public AtomicSwapClientFactory AtomicSwapClientFactory { get; }
 
         private readonly UserManager<ApplicationUser> _userManager;
         private readonly JsonSerializerSettings _serializerSettings;
@@ -53,6 +57,7 @@ namespace BTCPayServer.Controllers
 
         CurrencyNameTable _currencyTable;
         public WalletsController(StoreRepository repo,
+                                 AtomicSwapRepository atomicSwapRepository,
                                  WalletRepository walletRepository,
                                  CurrencyNameTable currencyTable,
                                  BTCPayNetworkProvider networkProvider,
@@ -63,7 +68,8 @@ namespace BTCPayServer.Controllers
                                  IAuthorizationService authorizationService,
                                  ExplorerClientProvider explorerProvider,
                                  IFeeProviderFactory feeRateProvider,
-                                 BTCPayWalletProvider walletProvider)
+                                 BTCPayWalletProvider walletProvider,
+                                 AtomicSwapClientFactory atomicSwapClientFactory)
         {
             _currencyTable = currencyTable;
             Repository = repo;
@@ -77,6 +83,8 @@ namespace BTCPayServer.Controllers
             ExplorerClientProvider = explorerProvider;
             _feeRateProvider = feeRateProvider;
             _walletProvider = walletProvider;
+            AtomicSwapClientFactory = atomicSwapClientFactory;
+            AtomicSwapRepository = atomicSwapRepository;
         }
 
         // Borrowed from https://github.com/ManageIQ/guides/blob/master/labels.md

BTCPayServer/Controllers/WalletsControllers.XSwap.cs

@@ -0,0 +1,398 @@
+using System;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using BTCPayServer.AtomicSwaps;
+using BTCPayServer.Data;
+using BTCPayServer.ModelBinders;
+using BTCPayServer.Rating;
+using BTCPayServer.Services.Rates;
+using BTCPayServer.Views.Wallets;
+using Microsoft.AspNetCore.Mvc;
+using NBitcoin;
+using NBitcoin.DataEncoders;
+
+namespace BTCPayServer.Controllers
+{
+
+    public partial class WalletsController : Controller
+    {
+        [Route("{walletId}/xswap")]
+        public async Task<IActionResult> AtomicSwapList([ModelBinder(typeof(WalletIdModelBinder))] WalletId walletId)
+        {
+            var derivationStrategy = await GetDerivationStrategy(walletId);
+            if (derivationStrategy == null)
+                return NotFound();
+            ListViewModel list = new ListViewModel();
+            list.CryptoCode = walletId.CryptoCode;
+            foreach (var entry in AtomicSwapRepository.GetEntries(walletId))
+            {
+                ListViewModel.SwapItem item = new ListViewModel.SwapItem()
+                {
+                    WalletId = walletId.ToString(),
+                    OfferId = entry.Id,
+                    Partner = entry.Partner,
+                    Role = entry.Role.ToString(),
+                    Status = entry.Status.ToString(),
+                    Timestamp = entry.Offer.CreatedAt,
+                    Sent = FormatAmount(entry.Sent),
+                    Received = FormatAmount(entry.Received),
+                };
+                list.Swaps.Add(item);
+            }
+            return View(list);
+        }
+
+        private string FormatAmount(AtomicSwapEscrowData entry)
+        {
+            return _currencyTable.DisplayFormatCurrency(entry.Amount.ToDecimal(MoneyUnit.BTC), entry.CryptoCode);
+        }
+
+        [Route("{walletId}/xswap/new")]
+        public async Task<IActionResult> NewAtomicSwap([ModelBinder(typeof(WalletIdModelBinder))] WalletId walletId)
+        {
+            var derivationStrategy = await GetDerivationStrategy(walletId);
+            if (derivationStrategy == null)
+                return NotFound();
+            var storeData = await Repository.FindStore(walletId.StoreId, GetUserId());
+            var wallets = await GetNamedWallets(walletId.CryptoCode);
+            var newVM = new NewViewModel();
+            var rateRules = storeData.GetStoreBlob().GetRateRules(NetworkProvider);
+            newVM.SetWalletList(wallets, walletId.ToString());
+            newVM.CryptoCode = walletId.CryptoCode;
+            return View(newVM);
+        }
+
+        private async Task<NamedWallet[]> GetNamedWallets(string fromCrypto)
+        {
+            var stores = await Repository.GetStoresByUserId(GetUserId());
+            return stores
+                    .SelectMany(s => s.GetSupportedPaymentMethods(NetworkProvider)
+                                    .OfType<DerivationSchemeSettings>()
+                                     .Where(p => p.Network.BlockTime != null)
+                                     .Where(p => p != null && ExplorerClientProvider.IsAvailable(p.Network))
+                                     .Select(p => new NamedWallet()
+                                     {
+                                         Name = $"{p.PaymentId.CryptoCode}: {s.StoreName}",
+                                         DerivationStrategy = p,
+                                         CryptoCode = p.PaymentId.CryptoCode,
+                                         WalletId = new WalletId(s.Id, p.PaymentId.CryptoCode),
+                                         Rule = GetRuleNoSpread(s.GetStoreBlob(), fromCrypto, p.PaymentId.CryptoCode),
+                                         Spread = s.GetStoreBlob().Spread
+                                     }))
+                                     .ToArray();
+        }
+
+        private RateRule GetRuleNoSpread(StoreBlob storeBlob, string cryptoCodeA, string cryptoCodeB)
+        {
+            var rules = storeBlob.GetRateRules(NetworkProvider);
+            rules.Spread = 0;
+            var rule = rules.GetRuleFor(new CurrencyPair(cryptoCodeA, cryptoCodeB));
+            return rule;
+        }
+
+        [TempData]
+        public string StatusMessage { get; set; }
+        public string CreatedOfferId { get; private set; }
+
+        [Route("{walletId}/xswap/new")]
+        [HttpPost]
+        public async Task<IActionResult> NewAtomicSwap(
+            [ModelBinder(typeof(WalletIdModelBinder))]
+            WalletId walletId,
+            NewViewModel newVM)
+        {
+            var fromWallet = await GetDerivationStrategy(walletId);
+            var statusAsync = ExplorerClientProvider.GetExplorerClient(fromWallet.Network).GetStatusAsync();
+            if (fromWallet == null)
+                return NotFound();
+            var wallets = await GetNamedWallets(walletId.CryptoCode);
+            newVM.SetWalletList(wallets, newVM.SelectedWallet);
+            newVM.CryptoCode = fromWallet.Network.CryptoCode;
+            if (!WalletId.TryParse(newVM.SelectedWallet, out var selectedWalletId))
+            {
+                ModelState.AddModelError(nameof(newVM.SelectedWallet), "Invalid wallet id");
+                return View(newVM);
+            }
+            var toWallet = await GetDerivationStrategy(selectedWalletId);
+            if (toWallet == null)
+            {
+                ModelState.AddModelError(nameof(newVM.SelectedWallet), "Invalid wallet id");
+                return View(newVM);
+            }
+
+            var id = Encoders.Base58.EncodeData(RandomUtils.GetBytes(20));
+            AtomicSwapOffer offer = new AtomicSwapOffer();
+            offer.MarketMakerUri = new Uri($"{this.Request.GetAbsoluteRoot().WithTrailingSlash()}api/xswap/{id}", UriKind.Absolute);
+            offer.Offer = new AtomicSwapOfferAsset()
+            {
+                Amount = Money.Coins((decimal)newVM.Amount),
+                CryptoCode = walletId.CryptoCode,
+            };
+
+            var minRelayFee = (await statusAsync).BitcoinStatus.MinRelayTxFee;
+            var minimumAmount = minRelayFee.GetFee(200); // Arbitrary but should cover the dust of any output
+            if (offer.Offer.Amount <= minimumAmount)
+            {
+                ModelState.AddModelError(nameof(newVM.Amount), $"Amount must be above {minimumAmount}");
+                return View(newVM);
+            }
+            offer.Price = new AtomicSwapOfferAsset()
+            {
+                CryptoCode = toWallet.PaymentId.CryptoCode
+            };
+            var lockTimespan = TimeSpan.FromDays(2);
+            offer.CreatedAt = DateTimeOffset.UtcNow;
+
+            var storeData = await Repository.FindStore(walletId.StoreId, GetUserId());
+            if (ModelState.IsValid)
+            {
+                var pair = new CurrencyPair("AAA", "BBB");
+                newVM.RateRule = $"{pair} = {newVM.RateRule}";
+
+                if (RateRules.TryParse(newVM.RateRule, out var rules, out var rateRulesErrors))
+                {
+                    rules.Spread = (decimal)newVM.Spread / 100.0m;
+                    var rateResult = await RateFetcher.FetchRate(pair, rules, CancellationToken.None);
+                    if (rateResult.BidAsk == null)
+                    {
+                        string errorMessage = "Error when fetching rate";
+                        if (rateResult.EvaluatedRule != null)
+                        {
+                            errorMessage += $" ({rateResult.EvaluatedRule})";
+                        }
+                        ModelState.AddModelError(nameof(newVM.RateRule), errorMessage);
+                    }
+                    else
+                    {
+                        offer.Price.Amount = Money.Coins(offer.Offer.Amount.ToDecimal(MoneyUnit.BTC) * rateResult.BidAsk.Ask);
+
+                        rules.Spread = 0;
+                        offer.Rule = rules.GetRuleFor(pair).ToString();
+                    }
+                }
+                else
+                {
+                    string errorDetails = "";
+                    if (rateRulesErrors.Count > 0)
+                    {
+                        errorDetails = $" ({rateRulesErrors[0]})";
+                    }
+                    ModelState.AddModelError(nameof(newVM.RateRule), $"Impossible to parse rate rules{errorDetails}");
+                }
+            }
+            if (!ModelState.IsValid)
+                return View(newVM);
+
+            var statusSent = ExplorerClientProvider.GetExplorerClient(offer.Offer.CryptoCode).GetStatusAsync();
+            var statusReceived = ExplorerClientProvider.GetExplorerClient(offer.Price.CryptoCode).GetStatusAsync();
+
+            offer.Offer.LockTime = new LockTime((await statusSent).ChainHeight + fromWallet.Network.GetBlockCount(lockTimespan));
+            offer.Price.LockTime = new LockTime((await statusReceived).ChainHeight + toWallet.Network.GetBlockCount(lockTimespan));
+            StatusMessage = $"Offer created, share the following link with the marker takers: {offer.MarketMakerUri}";
+            CreatedOfferId = id;
+
+            var entry = new AtomicSwapEntry();
+            entry.Offer = offer;
+            entry.Role = XSwapRole.Maker;
+            entry.Status = XSwapStatus.WaitingTaker;
+            entry.Sent = new SentAtomicSwapAsset(offer.Offer)
+            {
+                Refund = await GetDestination(fromWallet),
+                WalletId = walletId,
+            };
+            entry.Received = new ReceivedAtomicSwapAsset(offer.Price)
+            {
+                Destination = await GetDestination(toWallet),
+                WalletId = selectedWalletId
+            };
+            await AtomicSwapRepository.SaveEntry(walletId, id, entry);
+            return RedirectToAction(nameof(AtomicSwapDetails), new { offerId = id, walletId = walletId.ToString() });
+        }
+
+        private async Task<Script> GetDestination(DerivationSchemeSettings derivationStrategy)
+        {
+            var explorer = this.ExplorerClientProvider.GetExplorerClient(derivationStrategy.PaymentId.CryptoCode);
+            var scriptPubKey = (await explorer.GetUnusedAsync(derivationStrategy.AccountDerivation, NBXplorer.DerivationStrategy.DerivationFeature.Deposit, reserve: true)).ScriptPubKey;
+            return scriptPubKey;
+        }
+
+        [Route("{walletId}/xswap/take")]
+        public IActionResult TakeAtomicSwap(WalletId walletId)
+        {
+            return View(new TakeViewModel());
+        }
+
+        [Route("{walletId}/xswap/{offerId}/details")]
+        public async Task<IActionResult> AtomicSwapDetails(
+            [ModelBinder(typeof(WalletIdModelBinder))]
+            WalletId walletId,
+            string offerId)
+        {
+            var derivationStrategy = await GetDerivationStrategy(walletId);
+            if (derivationStrategy == null)
+                return NotFound();
+            var offer = await AtomicSwapRepository.GetEntry(offerId);
+            if (offer.Status == XSwapStatus.WaitingTaker)
+            {
+                if (offer.Role == XSwapRole.Maker)
+                {
+                    var vm = new AtomicSwapDetailsMarkerWaitingTakerViewModel()
+                    {
+                        ToSend = FormatAmount(offer.Sent),
+                        ToReceive = FormatAmount(offer.Received),
+                        OfferUri = new Uri($"{this.Request.GetAbsoluteRoot().WithTrailingSlash()}api/xswap/{offerId}", UriKind.Absolute)
+                    };
+                    return View("AtomicSwapDetailsMarkerWaitingTaker", vm);
+                }
+                if (offer.Role == XSwapRole.Taker)
+                {
+                    var vm = new AtomicSwapDetailsTakerWaitingTakerViewModel()
+                    {
+                        ToSend = FormatAmount(offer.Sent),
+                        ToReceive = FormatAmount(offer.Received),
+                        WalletId = walletId.ToString(),
+                        RefundTime = await GetRefundTime(offer),
+                    };
+                    var wallets = (await GetNamedWallets(offer.Received.CryptoCode)).Where(w => w.DerivationStrategy.PaymentId.CryptoCode == offer.Received.CryptoCode).ToArray();
+                    vm.SetWalletList(wallets, null);
+                    return View("AtomicSwapDetailsTakerWaitingTaker", vm);
+                }
+            }
+            else if (offer.Status == XSwapStatus.WaitingEscrow)
+            {
+                var network = NetworkProvider.GetNetwork<BTCPayNetwork>(offer.Sent.CryptoCode);
+                var vm = new AtomicSwapEscrowViewModel()
+                {
+                    ToSend = FormatAmount(offer.Sent),
+                    ToReceive = FormatAmount(offer.Received),
+                    SentToWalletId = walletId.ToString(),
+                    SentFromWalletId = offer.Sent.WalletId.ToString(),
+                    EscrowAddress = offer.Sent.GetEscrow().ToScript().GetDestinationAddress(network.NBitcoinNetwork).ToString(),
+                    Amount = offer.Sent.Amount.ToString(),
+                    RefundTime = await GetRefundTime(offer)
+                };
+                return View("AtomicSwapEscrow", vm);
+            }
+            return NotFound();
+        }
+
+        public class RefundTime
+        {
+            public int BlockCount { get; set; }
+            public TimeSpan Time { get; set; }
+        }
+        private async Task<RefundTime> GetRefundTime(AtomicSwapEntry offer)
+        {
+            var status = await ExplorerClientProvider.GetExplorerClient(offer.Sent.CryptoCode).GetStatusAsync();
+            var network = NetworkProvider.GetNetwork(offer.Sent.CryptoCode);
+            var blocksToWait = Math.Max(0, offer.Sent.LockTime.Height - status.ChainHeight);
+            var refundTime = network.GetTimeSpan(blocksToWait);
+            return new RefundTime() { BlockCount = blocksToWait, Time = refundTime };
+        }
+
+        [Route("{walletId}/xswap/take")]
+        [HttpPost]
+        public async Task<IActionResult> TakeAtomicSwap([ModelBinder(typeof(WalletIdModelBinder))] WalletId walletId, TakeViewModel takeViewModel)
+        {
+            var derivationStrategy = await GetDerivationStrategy(walletId);
+            var makerUri = new Uri(takeViewModel.MakerUri, UriKind.Absolute);
+            AtomicSwapClient client = AtomicSwapClientFactory.Create(makerUri);
+            var offer = await client.GetOffer();
+            if (offer == null)
+            {
+                ModelState.AddModelError(nameof(takeViewModel.MakerUri), "Offer not found");
+            }
+            else
+            {
+                if (offer.Offer.CryptoCode != walletId.CryptoCode)
+                {
+                    ModelState.AddModelError(nameof(takeViewModel.MakerUri), $"Offer for {offer.Offer.CryptoCode}, but this wallet is for {walletId.CryptoCode}");
+                }
+            }
+            if (!ModelState.IsValid)
+                return View(takeViewModel);
+            var entry = new AtomicSwapEntry()
+            {
+                Partner = new Uri(takeViewModel.MakerUri, UriKind.Absolute).DnsSafeHost,
+                OtherUri = makerUri,
+                Offer = offer,
+                Received = new ReceivedAtomicSwapAsset(offer.Offer)
+                {
+                    OtherKey = offer.Offer.Pubkey,
+                    Destination = await GetDestination(derivationStrategy),
+                    WalletId = walletId
+                },
+                Sent = new SentAtomicSwapAsset(offer.Price)
+                {
+                    OtherKey = offer.Price.Pubkey,
+                },
+                Role = XSwapRole.Taker,
+                Status = XSwapStatus.WaitingTaker
+            };
+            var id = Encoders.Base58.EncodeData(RandomUtils.GetBytes(20));
+            CreatedOfferId = id;
+            await AtomicSwapRepository.SaveEntry(walletId, id, entry);
+            return RedirectToAction(nameof(AtomicSwapDetails), new { offerId = id, walletId = walletId.ToString() });
+        }
+
+        [Route("{walletId}/xswap/{offerId}/accept")]
+        public async Task<IActionResult> AcceptAtomicSwapOffer(
+            [ModelBinder(typeof(WalletIdModelBinder))] WalletId walletId,
+            string offerId, AtomicSwapDetailsTakerWaitingTakerViewModel viewModel)
+        {
+            var derivationStrategy = await GetDerivationStrategy(walletId);
+            if (derivationStrategy == null)
+                return NotFound();
+
+            var entry = await AtomicSwapRepository.GetEntry(offerId);
+            if (entry == null)
+                return NotFound();
+
+
+            WalletId.TryParse(viewModel.SelectedWallet, out var selectedWalletId);
+            var destinationStrategy = await GetDerivationStrategy(selectedWalletId);
+
+            entry.Sent.WalletId = walletId;
+            entry.Sent.Refund = await GetDestination(derivationStrategy);
+            entry.Sent.MyKey = new Key();
+
+            entry.Received.Destination = await GetDestination(destinationStrategy);
+            entry.Received.WalletId = selectedWalletId;
+            entry.Received.MyKey = new Key();
+            entry.Status = XSwapStatus.WaitingEscrow;
+
+            var maker = AtomicSwapClientFactory.Create(entry.OtherUri);
+            var response = await maker.Take(new AtomicSwapTakeRequest()
+            {
+                TakerUri = new Uri($"{this.Request.GetAbsoluteRoot().WithTrailingSlash()}api/xswap/{entry.Id}", UriKind.Absolute),
+                MakerReceivedCryptoPubkey = entry.Sent.MyKey.PubKey,
+                MakerSentCryptoPubkey = entry.Received.MyKey.PubKey,
+            });
+
+            if (response == null)
+                return NotFound();
+
+            entry.Received.OtherKey = response.MakerSentCryptoPubkey;
+            entry.Sent.OtherKey = response.MakerReceivedCryptoPubkey;
+            entry.Hash = response.Hash;
+
+            await AtomicSwapRepository.UpdateEntry(offerId, entry);
+
+            return RedirectToAction(nameof(AtomicSwapDetails), new { offerId = offerId, walletId = walletId.ToString() });
+        }
+
+        async Task<DerivationSchemeSettings> GetDerivationStrategy(WalletId walletId)
+        {
+            if (walletId?.StoreId == null || GetUserId() == null)
+                return null;
+            var storeData = await this.Repository.FindStore(walletId.StoreId, GetUserId());
+            var strategy = storeData.GetSupportedPaymentMethods(NetworkProvider)
+                     .OfType<DerivationSchemeSettings>()
+                     .FirstOrDefault(s => s.PaymentId.CryptoCode == walletId.CryptoCode);
+            if (strategy == null || !ExplorerClientProvider.IsAvailable(strategy.Network))
+                return null;
+            return strategy;
+        }
+    }
+}

BTCPayServer/EscrowScriptBuilder.cs

@@ -0,0 +1,114 @@
+using NBitcoin;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+
+namespace BTCPayServer
+{
+    //<Bob.PubKey>
+    //OP_DEPTH OP_3 OP_EQUAL
+    //OP_IF
+
+    //	OP_SWAP
+    //	<Alice.PubKey> OP_CHECKSIGVERIFY OP_CODESEPARATOR
+    //OP_ELSE
+    //    0 OP_CLTV OP_DROP
+    //OP_ENDIF
+    //OP_CHECKSIG
+    public class EscrowScriptPubKeyParameters
+    {
+
+        public EscrowScriptPubKeyParameters()
+        {
+
+        }
+
+        public EscrowScriptPubKeyParameters(PubKey initiator, PubKey receiver, LockTime lockTime)
+        {
+            this.Initiator = initiator;
+            this.Receiver = receiver;
+            this.LockTime = lockTime;
+        }
+        public PubKey Initiator
+        {
+            get; set;
+        }
+
+        public PubKey Receiver
+        {
+            get; set;
+        }
+        public LockTime LockTime
+        {
+            get; set;
+        }
+        static readonly Comparer<PubKey> LexicographicComparer = Comparer<PubKey>.Create((a, b) => Comparer<string>.Default.Compare(a?.ToHex(), b?.ToHex()));
+
+
+        // OP_DEPTH 2 OP_EQUAL
+        // OP_IF
+        //     <Receiver.PubKey> OP_CHECKSIGVERIFY
+        // OP_ELSE
+        //     0 OP_CLTV OP_DROP
+        // OP_ENDIF
+        // <Initiator.PubKey> OP_CHECKSIG
+        public Script ToRedeemScript()
+        {
+            if (Initiator == null || Receiver == null || LockTime == default(LockTime))
+                throw new InvalidOperationException("Parameters are incomplete");
+            EscrowScriptPubKeyParameters parameters = new EscrowScriptPubKeyParameters();
+            List<Op> ops = new List<Op>();
+            ops.Add(OpcodeType.OP_DEPTH);
+            ops.Add(OpcodeType.OP_2);
+            ops.Add(OpcodeType.OP_EQUAL);
+            ops.Add(OpcodeType.OP_IF);
+            {
+                ops.Add(Op.GetPushOp(Receiver.ToBytes()));
+                ops.Add(OpcodeType.OP_CHECKSIGVERIFY);
+            }
+            ops.Add(OpcodeType.OP_ELSE);
+            {
+                ops.Add(Op.GetPushOp(LockTime));
+                ops.Add(OpcodeType.OP_CHECKLOCKTIMEVERIFY);
+                ops.Add(OpcodeType.OP_DROP);
+            }
+            ops.Add(OpcodeType.OP_ENDIF);
+            ops.Add(Op.GetPushOp(Initiator.ToBytes()));
+            ops.Add(OpcodeType.OP_CHECKSIG);
+            return new Script(ops.ToArray());
+        }
+
+
+        public override bool Equals(object obj)
+        {
+            EscrowScriptPubKeyParameters item = obj as EscrowScriptPubKeyParameters;
+            if (item == null)
+                return false;
+            return ToRedeemScript().Equals(item.ToRedeemScript());
+        }
+        public static bool operator ==(EscrowScriptPubKeyParameters a, EscrowScriptPubKeyParameters b)
+        {
+            if (System.Object.ReferenceEquals(a, b))
+                return true;
+            if (((object)a == null) || ((object)b == null))
+                return false;
+            return a.ToRedeemScript() == b.ToRedeemScript();
+        }
+
+        public static bool operator !=(EscrowScriptPubKeyParameters a, EscrowScriptPubKeyParameters b)
+        {
+            return !(a == b);
+        }
+
+        public override int GetHashCode()
+        {
+            return ToRedeemScript().GetHashCode();
+        }
+
+        internal Script ToScript()
+        {
+            return ToRedeemScript().WitHash.ScriptPubKey.Hash.ScriptPubKey;
+        }
+    }
+}

BTCPayServer/Hosting/BTCPayServerServices.cs

@@ -53,6 +53,7 @@ using Microsoft.AspNetCore.Routing;
 using Microsoft.AspNetCore.Authentication;
 using Microsoft.AspNetCore.Authorization;
 using BTCPayServer.Security.Bitpay;
+using BTCPayServer.Views.Wallets;
 using Serilog;
 
 namespace BTCPayServer.Hosting
@@ -69,6 +70,8 @@ namespace BTCPayServer.Hosting
                 o.UseOpenIddict<BTCPayOpenIdClient, BTCPayOpenIdAuthorization, OpenIddictScope<string>, BTCPayOpenIdToken, string>();
             });
             services.AddHttpClient();
+            services.TryAddSingleton<AtomicSwapRepository>();
+            services.TryAddSingleton<AtomicSwapClientFactory>();
             services.AddHttpClient(nameof(ExplorerClientProvider), httpClient =>
             {
                 httpClient.Timeout = Timeout.InfiniteTimeSpan;

BTCPayServer/Services/AtomicSwapClientFactory.cs

@@ -0,0 +1,23 @@
+using System;
+using System.Net.Http;
+using BTCPayServer.AtomicSwaps;
+
+namespace BTCPayServer.Services
+{
+    public class AtomicSwapClientFactory
+    {
+        public AtomicSwapClientFactory(IHttpClientFactory httpClientFactory)
+        {
+            HttpClientFactory = httpClientFactory;
+        }
+
+        public IHttpClientFactory HttpClientFactory { get; }
+
+        public AtomicSwapClient Create(Uri serverUri)
+        {
+            var client = new AtomicSwapClient(serverUri);
+            client.SetClient(HttpClientFactory.CreateClient());
+            return client;
+        }
+    }
+}

BTCPayServer/Views/Wallets/AtomicSwapDetails.cshtml

@@ -0,0 +1,21 @@
+@*@model OfferViewModel
+@{
+    Layout = "_Layout.cshtml";
+}
+
+<section>
+    <div class="container">
+        <div class="row">
+            <div class="col-lg-12 text-center">
+                <h2 class="section-heading">@Model.Title</h2>
+                <hr class="primary">
+                <p>You need to send <b>@Model.ToSend</b> to <b>@Model.EscrowAddress</b>, if the other party get unresponsive, you will get back money on your <a href="@Model.WalletUrl">BTCPay store's wallet</a> after @Model.RefundTime.</p>
+            </div>
+        </div>
+        <div class="row">
+            <div class="col-lg-12 text-center">
+                
+            </div>
+        </div>
+    </div>
+</section>*@

BTCPayServer/Views/Wallets/AtomicSwapDetailsMarkerWaitingTaker.cshtml

@@ -0,0 +1,21 @@
+@model AtomicSwapDetailsMarkerWaitingTakerViewModel
+@{
+    Layout = "../Shared/_NavLayout.cshtml";
+    ViewData["Title"] = "Manage atomic swaps";
+    ViewData.SetActivePageAndTitle(WalletsNavPages.AtomicSwaps);
+}
+
+
+<div class="row">
+    <div class="col-md-10">
+        <p>You will buy <b>@Model.ToReceive</b> against <b>@Model.ToSend</b>, you need to find a partner for this trade.</p>
+    </div>
+</div>
+<div class="row">
+    <div class="col-md-10 text-center">
+        <div class="alert alert-warning alert-dismissible" role="alert">
+            <span>Share the following link with the party willing to take your offer</span>
+            <span><b>@Model.OfferUri</b></span>
+        </div>
+    </div>
+</div>

BTCPayServer/Views/Wallets/AtomicSwapDetailsMarkerWaitingTakerViewModel.cs

@@ -0,0 +1,14 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+
+namespace BTCPayServer.Views.Wallets
+{
+    public class AtomicSwapDetailsMarkerWaitingTakerViewModel
+    {
+        public string ToSend { get; set; }
+        public string ToReceive { get; internal set; }
+        public Uri OfferUri { get; set; }
+    }
+}

BTCPayServer/Views/Wallets/AtomicSwapDetailsTakerWaitingTaker.cshtml

@@ -0,0 +1,27 @@
+@model AtomicSwapDetailsTakerWaitingTakerViewModel
+@{
+    Layout = "../Shared/_NavLayout.cshtml";
+    ViewData["Title"] = "Manage atomic swaps";
+    ViewData.SetActivePageAndTitle(WalletsNavPages.AtomicSwaps);
+}
+
+
+<div class="row">
+    <div class="col-md-10">
+        <p>You will buy <b>@Model.ToReceive</b> against <b>@Model.ToSend</b>, if your peer get unresponsive, you will get back your money on <a asp-action="WalletTransactions" asp-route-walletId="@Model.WalletId">your wallet</a> in <b>@Model.RefundTime.Time.TimeString()  (@Model.RefundTime.BlockCount blocks remaining)</b>.</p>
+    </div>
+</div>
+<div class="row">
+    <div class="col-md-10">
+        <form method="post">
+            <div class="form-group">
+                <label asp-for="SelectedWallet" class="control-label"></label>
+                <select asp-for="SelectedWallet" asp-items="Model.WalletList" class="form-control"></select>
+                <span asp-validation-for="SelectedWallet" class="text-danger"></span>
+            </div>
+            <div class="form-group">
+                <input type="submit" value="Accept offer" asp-action="AcceptAtomicSwapOffer" class="btn btn-primary" />
+            </div>
+        </form>
+    </div>
+</div>

BTCPayServer/Views/Wallets/AtomicSwapDetailsTakerWaitingTakerViewModel.cs

@@ -0,0 +1,29 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel.DataAnnotations;
+using System.Linq;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Mvc.Rendering;
+
+namespace BTCPayServer.Views.Wallets
+{
+    public class AtomicSwapDetailsTakerWaitingTakerViewModel
+    {
+        public string ToSend { get; set; }
+        public string ToReceive { get; internal set; }
+        public string WalletId { get; set; }
+        public Controllers.WalletsController.RefundTime RefundTime { get; set; }
+
+        [Display(Name = "Receive on wallet...")]
+        public string SelectedWallet { get; set; }
+        public SelectList WalletList { get; set; }
+
+        public void SetWalletList(NamedWallet[] namedWallet, string selectedWallet)
+        {
+            var choices = namedWallet.Select(o => new { Name = o.Name, Value = o.WalletId.ToString() }).ToArray();
+            var chosen = choices.FirstOrDefault(f => f.Value == selectedWallet) ?? choices.FirstOrDefault();
+            WalletList = new SelectList(choices, nameof(chosen.Value), nameof(chosen.Name), chosen);
+            SelectedWallet = chosen.Value;
+        }
+    }
+}

BTCPayServer/Views/Wallets/AtomicSwapEscrow.cshtml

@@ -0,0 +1,25 @@
+@model AtomicSwapEscrowViewModel
+@{
+    Layout = "../Shared/_NavLayout.cshtml";
+    ViewData["Title"] = "Manage atomic swaps";
+    ViewData.SetActivePageAndTitle(WalletsNavPages.AtomicSwaps);
+}
+
+
+<div class="row">
+    <div class="col-md-10">
+        <p>You will buy <b>@Model.ToReceive</b> against <b>@Model.ToSend</b>, if your peer get unresponsive, you will get back your money in <a asp-action="WalletTransactions" asp-route-walletId="@Model.SentToWalletId">your wallet</a> in <b>@Model.RefundTime.Time.TimeString() (@Model.RefundTime.BlockCount blocks remaining)</b>.</p>
+    </div>
+</div>
+
+<div class="row">
+    <div class="col-md-10">
+        <form asp-action="WalletSend" method="get">
+            <div class="form-group">
+                <input type="submit" value="Proceed to payment" class="btn btn-primary" />
+                <input type="hidden" name="defaultDestination" value="@Model.EscrowAddress" />
+                <input type="hidden" name="defaultAmount" value="@Model.Amount" />
+            </div>
+        </form>
+    </div>
+</div>

BTCPayServer/Views/Wallets/AtomicSwapEscrowViewModel.cs

@@ -0,0 +1,18 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+
+namespace BTCPayServer.Views.Wallets
+{
+    public class AtomicSwapEscrowViewModel
+    {
+        public string ToSend { get; set; }
+        public string ToReceive { get; internal set; }
+        public string SentToWalletId { get; set; }
+        public Controllers.WalletsController.RefundTime RefundTime { get; set; }
+        public string SentFromWalletId { get; set; }
+        public string EscrowAddress { get; internal set; }
+        public string Amount { get; set; }
+    }
+}

BTCPayServer/Views/Wallets/AtomicSwapList.cshtml

@@ -0,0 +1,47 @@
+@model ListViewModel
+@{
+    Layout = "../Shared/_NavLayout.cshtml";
+    ViewData["Title"] = "Manage atomic swaps";
+    ViewData.SetActivePageAndTitle(WalletsNavPages.AtomicSwaps);
+}
+
+<h4>@ViewData["Title"]</h4>
+<div class="row">
+    <div class="col-md-10 text-center">
+        <partial name="_StatusMessage" for="@TempData["TempDataProperty-StatusMessage"]" />
+    </div>
+</div>
+
+<div class="row">
+    <div class="col-md-10">
+        <a asp-route-walletId="@this.Context.GetRouteValue("walletId")" asp-action="NewAtomicSwap" class="btn btn-primary" role="button"><span class="fa fa-plus"></span> Make a @Model.CryptoCode offer</a>&nbsp;
+        <a asp-route-walletId="@this.Context.GetRouteValue("walletId")" asp-action="TakeAtomicSwap" class="btn btn-secondary" role="button"><span class="fa fa-sign-in"></span> Take a @Model.CryptoCode offer</a>
+        <table class="table table-sm table-responsive-md">
+            <thead>
+                <tr>
+                    <th style="text-align:center">Date</th>
+                    <th style="text-align:center">Partner</th>
+                    <th style="text-align:right">Send</th>
+                    <th style="text-align:right">Receive</th>
+                    <th style="text-align:center">Status</th>
+                    <th style="text-align:right">Actions</th>
+                </tr>
+            </thead>
+            <tbody>
+                @foreach (var swap in Model.Swaps)
+                {
+                    <tr>
+                        <td>@swap.Timestamp.ToTimeAgo()</td>
+                        <td>@swap.Partner</td>
+                        <td style="text-align:right;">@swap.Sent</td>
+                        <td style="text-align:right;">@swap.Received</td>
+                        <td style="text-align:center">@swap.Status</td>
+                        <td style="text-align:right">
+                            <a asp-action="AtomicSwapDetails" asp-route-walletId="@swap.WalletId" asp-route-offerId="@swap.OfferId">Details</a>
+                        </td>
+                    </tr>
+                }
+            </tbody>
+        </table>
+    </div>
+</div>

BTCPayServer/Views/Wallets/AtomicSwapRepository.cs

@@ -0,0 +1,151 @@
+using System;
+using System.Collections.Concurrent;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using BTCPayServer.AtomicSwaps;
+using NBitcoin;
+using Newtonsoft.Json;
+
+namespace BTCPayServer.Views.Wallets
+{
+    public class AtomicSwapRepository
+    {
+        ConcurrentDictionary<string, AtomicSwapEntry> _Offers = new ConcurrentDictionary<string, AtomicSwapEntry>();
+        
+        public Task SaveEntry(WalletId walletId, string offerId, AtomicSwapEntry entry)
+        {
+            entry.Id = offerId;
+            _Offers.TryAdd(offerId, entry);
+            _OfferIdsByWalletId.Add(walletId, offerId);
+            return Task.CompletedTask;
+        }
+
+        public Task<AtomicSwapEntry> GetEntry(string offerId)
+        {
+            _Offers.TryGetValue(offerId, out var offer);
+            return Task.FromResult(offer);
+        }
+
+        internal IEnumerable<AtomicSwapEntry> GetEntries(WalletId walletId)
+        {
+            if (!_OfferIdsByWalletId.TryGetValue(walletId, out var offers))
+                return Array.Empty<AtomicSwapEntry>();
+            return _OfferIdsByWalletId[walletId].Select(c => GetEntry(c).Result).OrderByDescending(o => o.Offer.CreatedAt);
+        }
+
+        MultiValueDictionary<WalletId, string> _OfferIdsByWalletId = new MultiValueDictionary<WalletId, string>();
+
+        internal Task UpdateEntry(string offerId, AtomicSwapEntry entry)
+        {
+            _Offers.AddOrUpdate(offerId, entry, (k, oldv) => entry);
+            return Task.CompletedTask;
+        }
+    }
+
+    public enum XSwapRole
+    {
+        Maker,
+        Taker
+    }
+
+    public enum XSwapStatus
+    {
+        WaitingTaker,
+        WaitingEscrow,
+        WaitingPeerEscrow,
+        WaitingBlocks,
+        CashingOut,
+        Refunding,
+        CashedOut,
+        Refunded
+    }
+
+    public class AtomicSwapEntry
+    {
+        [JsonConverter(typeof(Newtonsoft.Json.Converters.StringEnumConverter))]
+        public XSwapRole Role { get; set; }
+        [JsonConverter(typeof(Newtonsoft.Json.Converters.StringEnumConverter))]
+        public XSwapStatus Status { get; set; }
+        public AtomicSwapOffer Offer { get; set; }
+        public SentAtomicSwapAsset Sent { get; set; }
+        public ReceivedAtomicSwapAsset Received { get; set; }
+        public string Partner { get; set; }
+        public Uri OtherUri { get; set; }
+        public string Id { get; internal set; }
+
+        public Preimage Preimage { get; set; }
+
+        [JsonConverter(typeof(NBitcoin.JsonConverters.UInt160JsonConverter))]
+        public uint160 Hash { get; set; }
+    }
+
+    public class AtomicSwapEscrowData
+    {
+        public AtomicSwapEscrowData(AtomicSwapOfferAsset offerAsset)
+        {
+            Amount = offerAsset.Amount;
+            LockTime = offerAsset.LockTime;
+            CryptoCode = offerAsset.CryptoCode;
+        }
+        public AtomicSwapEscrowData()
+        {
+
+        }
+        public string CryptoCode { get; set; }
+        public Key MyKey { get; set; }
+        public PubKey OtherKey { get; set; }
+        public LockTime LockTime { get; set; }
+        public Money Amount { get; set; }
+        public WalletId WalletId { get; set; }
+        public EscrowScriptPubKeyParameters GetEscrow()
+        {
+            return new EscrowScriptPubKeyParameters(MyKey.PubKey, OtherKey, LockTime);
+        }
+    }
+
+    public class ReceivedAtomicSwapAsset : AtomicSwapEscrowData
+    {
+        public ReceivedAtomicSwapAsset(AtomicSwapOfferAsset offerAsset) : base(offerAsset)
+        {
+        }
+        public ReceivedAtomicSwapAsset()
+        {
+
+        }
+        public Script Destination { get; set; }
+    }
+
+    public class SentAtomicSwapAsset : AtomicSwapEscrowData
+    {
+        public SentAtomicSwapAsset(AtomicSwapOfferAsset offerAsset) : base(offerAsset)
+        {
+        }
+        public SentAtomicSwapAsset()
+        {
+
+        }
+        public Script Refund { get; set; }
+    }
+
+    public class AtomicSwapOffer
+    {
+        [JsonConverter(typeof(Newtonsoft.Json.Converters.UnixDateTimeConverter))]
+        public DateTimeOffset CreatedAt { get; set; }
+        public string Rule { get; set; }
+        public AtomicSwapOfferAsset Offer { get; set; }
+        public AtomicSwapOfferAsset Price { get; set; }
+        public Uri MarketMakerUri { get; set; }
+    }
+
+    public class AtomicSwapOfferAsset
+    {
+        public string CryptoCode { get; set; }
+        [JsonConverter(typeof(NBitcoin.JsonConverters.LockTimeJsonConverter))]
+        public LockTime LockTime { get; set; }
+        [JsonConverter(typeof(NBitcoin.JsonConverters.MoneyJsonConverter))]
+        public Money Amount { get; set; }
+        [JsonConverter(typeof(NBitcoin.JsonConverters.KeyJsonConverter))]
+        public PubKey Pubkey { get; set; }
+    }
+}

BTCPayServer/Views/Wallets/ListViewModel.cs

@@ -0,0 +1,24 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+
+namespace BTCPayServer.Views.Wallets
+{
+    public class ListViewModel
+    {
+        public class SwapItem
+        {
+            public string OfferId { get; set; }
+            public string WalletId { get; set; }
+            public DateTimeOffset Timestamp { get; set; }
+            public string Partner { get; set; }
+            public string Sent { get; set; }
+            public string Received { get; set; }
+            public string Status { get; set; }
+            public string Role { get; set; }
+        }
+        public string CryptoCode { get; set; }
+        public List<SwapItem> Swaps { get; set; } = new List<SwapItem>();
+    }
+}

BTCPayServer/Views/Wallets/NewAtomicSwap.cshtml

@@ -0,0 +1,73 @@
+@model NewViewModel
+@{
+    Layout = "../Shared/_NavLayout.cshtml";
+    ViewData["Title"] = "Create new atomic swap offer";
+    ViewData.SetActivePageAndTitle(WalletsNavPages.AtomicSwaps);
+}
+
+<h4>@ViewData["Title"]</h4>
+
+<div class="row">
+    <div class="col-md-10">
+        <form method="post">
+            <div asp-validation-summary="ModelOnly" class="text-danger"></div>
+            <div class="form-group">
+                <label asp-for="SelectedWallet" class="control-label"></label>
+                <select asp-for="SelectedWallet" asp-items="Model.WalletList" class="form-control" onchange="updateCryptoDestination();"></select>
+                <span asp-validation-for="SelectedWallet" class="text-danger"></span>
+            </div>
+            <div class="form-group">
+                <label asp-for="RateRule" class="control-label"></label>
+                <div class="input-group">
+                    <input asp-for="RateRule" class="form-control" />
+                    <div class="input-group-prepend">
+                        <span class="input-group-text" style="display:none;" id="cryptoDestination"></span>
+                    </div>
+                </div>
+                <span asp-validation-for="RateRule" class="text-danger"></span>
+            </div>
+            <div class="form-group">
+                <label asp-for="Amount"></label>
+                <div class="input-group">
+                    <input asp-for="Amount" class="form-control" />
+                    <div class="input-group-prepend">
+                        <span class="input-group-text">@Model.CryptoCode</span>
+                    </div>
+                </div>
+                <span asp-validation-for="Amount" class="text-danger"></span>
+            </div>
+            <div class="form-group">
+                <label asp-for="Spread"></label>
+                <div class="input-group">
+                    <input asp-for="Spread" class="form-control" />
+                    <div class="input-group-prepend">
+                        <span class="input-group-text">%</span>
+                    </div>
+                </div>
+                <span asp-validation-for="Spread" class="text-danger"></span>
+            </div>
+            <div class="form-group">
+                <input type="submit" value="New offer" class="btn btn-primary" />
+            </div>
+        </form>
+        <a asp-action="AtomicSwapList">Back to List</a>
+    </div>
+</div>
+
+@section Scripts
+    {
+    <script type="text/javascript">
+        var srvModel = @Html.Raw(Json.Serialize(Model));
+        $(function () {
+            updateCryptoDestination();
+        });
+        function updateCryptoDestination() {
+            var val = $("#SelectedWallet").val();
+            var selected = srvModel.walletData[val];
+            $("#cryptoDestination").text(selected.cryptoCode + " per " + '@Model.CryptoCode');
+            $("#RateRule").val(selected.rule);
+            $("#Spread").val(selected.spread * 100);
+            $("#cryptoDestination").show();
+        }
+    </script>
+}

BTCPayServer/Views/Wallets/NewViewModel.cs

@@ -0,0 +1,62 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel.DataAnnotations;
+using System.Linq;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Mvc.Rendering;
+using Microsoft.SqlServer.Server;
+
+namespace BTCPayServer.Views.Wallets
+{
+    public class NamedWallet
+    {
+        public string Name { get; set; }
+        public string CryptoCode { get; set; }
+        public WalletId WalletId { get; set; }
+        public Rating.RateRule Rule { get; set; }
+        public decimal Spread { get; set; }
+        public DerivationSchemeSettings DerivationStrategy { get; set; }
+    }
+    public class NewViewModel
+    {
+        public class NameWalletObj
+        {
+            public string CryptoCode { get; set; }
+            public decimal Spread { get; set; }
+            public string Rule { get; set; }
+        }
+        [Display(Name = "To wallet")]
+        public string SelectedWallet { get; set; }
+
+        [Display(Name = "Amount to receive in the destination wallet (or rating rule)")]
+        [Required()]
+        public string RateRule { get; set; }
+
+        [Range(0, double.MaxValue)]
+        [Display(Name = "Amount to send from this wallet")]
+        public double Amount { get; set; }
+
+        public string CryptoCode { get; set; }
+
+        [Display(Name = "Add a spread on exchange rate of ... %")]
+        [Range(0.0, 100.0)]
+        public double Spread
+        {
+            get;
+            set;
+        }
+
+        public Dictionary<WalletId, NameWalletObj> WalletData { get; set; }
+
+        public SelectList WalletList { get; set; }
+
+        public void SetWalletList(NamedWallet[] namedWallet, string selectedWallet)
+        {
+            var choices = namedWallet.Select(o => new { Name = o.Name, Value = o.WalletId.ToString() }).ToArray();
+            var chosen = choices.FirstOrDefault(f => f.Value == selectedWallet) ?? choices.FirstOrDefault();
+            WalletList = new SelectList(choices, nameof(chosen.Value), nameof(chosen.Name), chosen);
+            SelectedWallet = chosen.Value;
+            WalletData = namedWallet.ToDictionary(o => o.WalletId, o => new NameWalletObj() { CryptoCode = o.CryptoCode, Rule = o.Rule.ToString(), Spread = o.Spread });
+        }
+    }
+}

BTCPayServer/Views/Wallets/OfferViewModel.cs

@@ -0,0 +1,16 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+
+namespace BTCPayServer.Views.Wallets
+{
+    public class OfferViewModel
+    {
+        public string Title { get; set; }
+
+        public string EscrowAddress { get; set; }
+        public string WalletUrl { get; set; }
+        public string RefundTime { get; set; }
+    }
+}

BTCPayServer/Views/Wallets/TakeAtomicSwap.cshtml

@@ -0,0 +1,24 @@
+@model TakeViewModel
+@{
+    Layout = "../Shared/_NavLayout.cshtml";
+    ViewData["Title"] = "Take an atomic swap offer";
+    ViewData.SetActivePageAndTitle(WalletsNavPages.AtomicSwaps);
+}
+
+
+<div class="row">
+    <div class="col-md-10">
+        <form method="post">
+            <div asp-validation-summary="ModelOnly" class="text-danger"></div>
+            <div class="form-group">
+                <label asp-for="MakerUri" class="control-label"></label>*
+                <input asp-for="MakerUri" class="form-control" />
+                <span asp-validation-for="MakerUri" class="text-danger"></span>
+            </div>
+            <div class="form-group">
+                <input type="submit" value="Take offer" class="btn btn-primary" />
+            </div>
+        </form>
+        <a asp-action="AtomicSwapList">Back to List</a>
+    </div>
+</div>

BTCPayServer/Views/Wallets/TakeViewModel.cs

@@ -0,0 +1,18 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel.DataAnnotations;
+using System.Linq;
+using System.Threading.Tasks;
+using BTCPayServer.Validation;
+using Microsoft.AspNetCore.Mvc.Rendering;
+
+namespace BTCPayServer.Views.Wallets
+{
+    public class TakeViewModel
+    {
+        [Display(Name = "Maker's URI")]
+        [UriAttribute]
+        [Required]
+        public string MakerUri { get; set; }
+    }
+}

BTCPayServer/Views/Wallets/WalletsNavPages.cs

@@ -11,6 +11,7 @@ namespace BTCPayServer.Views.Wallets
         Transactions,
         Rescan,
         PSBT,
-        Settings
+        Settings,
+        AtomicSwaps
     }
 }

BTCPayServer/Views/Wallets/_Nav.cshtml

@@ -15,5 +15,6 @@
     {
         <a class="nav-link @ViewData.IsActivePage(WalletsNavPages.PSBT)" asp-action="WalletPSBT" asp-route-walletId="@this.Context.GetRouteValue("walletId")">PSBT</a>
         <a class="nav-link @ViewData.IsActivePage(WalletsNavPages.Settings)" asp-action="WalletSettings" asp-route-walletId="@this.Context.GetRouteValue("walletId")" id="WalletSettings">Settings</a>
+        <a class="nav-link @ViewData.IsActivePage(WalletsNavPages.AtomicSwaps)" asp-action="AtomicSwapList" asp-route-walletId="@this.Context.GetRouteValue("walletId")">Atomic Swaps</a>
     }
 </div>