Step NC05: Chat Provider SPI And Foundations

ArcChat.slnx

@@ -13,6 +13,7 @@
     <Project Path="packages/net-core/ArcChat.Net.Tests/ArcChat.Net.Tests.csproj" />
     <Project Path="packages/model-providers/ArcChat.ModelProviders.Core/ArcChat.ModelProviders.Core.csproj" />
     <Project Path="packages/model-providers/ArcChat.ModelProviders.Core.Tests/ArcChat.ModelProviders.Core.Tests.csproj" />
+    <Project Path="packages/model-providers/ArcChat.ModelProviders.Core.ContractTestKit/ArcChat.ModelProviders.Core.ContractTestKit.csproj" />
     <Project Path="packages/model-providers/ArcChat.ModelProviders.Tokenizer/ArcChat.ModelProviders.Tokenizer.csproj" />
     <Project Path="packages/model-providers/ArcChat.ModelProviders.Tokenizer.Tests/ArcChat.ModelProviders.Tokenizer.Tests.csproj" />
     <Project Path="packages/model-providers/ArcChat.ModelProviders.OpenAi/ArcChat.ModelProviders.OpenAi.csproj" />

Directory.Packages.props

@@ -29,6 +29,7 @@
     <!-- Net: NC02 transport and provider foundations. -->
     <PackageVersion Include="Microsoft.Extensions.Http.Resilience" Version="10.6.0" />
     <PackageVersion Include="Polly.Core" Version="8.6.6" />
+    <PackageVersion Include="SharpToken" Version="2.0.6" />
     <PackageVersion Include="System.IO.Pipelines" Version="10.0.8" />
     <PackageVersion Include="System.Threading.Channels" Version="10.0.8" />
     <PackageVersion Include="System.Threading.RateLimiting" Version="10.0.8" />

apps/desktop/ArcChat.Desktop.UiTests/NewChatViewModelTests.cs

@@ -72,6 +72,23 @@ public static async Task NewChatMaskAppliesContextAndModelOverrides()
         _ = conversation.Mask.ModelConfig.MaxTokens.Should().Be(2000);
     }
 
+    [Fact]
+    [System.Diagnostics.CodeAnalysis.SuppressMessage("Reliability", "CA2007:Consider calling ConfigureAwait on the awaited task", Justification = "Async disposal belongs to the test scope.")]
+    public static async Task NewChatProviderPickerIncludesReferenceProviders()
+    {
+        await using ArcChatDatabase database = await CreateDatabaseAsync().ConfigureAwait(true);
+        AppNavigator navigator = new AppNavigator();
+        NewChatViewModel newChat = CreateLoadedNewChat(database, navigator);
+
+        _ = newChat.Providers.Select(provider => provider.ProviderName).Should().Equal(
+            "OpenAI",
+            "Anthropic",
+            "Google",
+            "GenericOpenAI");
+        _ = newChat.Providers.Should().OnlyContain(provider => provider.Models.Length > 0);
+        _ = newChat.SelectedProvider!.ProviderName.Should().Be("OpenAI");
+    }
+
     private static NewChatViewModel CreateLoadedNewChat(ArcChatDatabase database, IAppNavigator navigator)
     {
         NewChatViewModel viewModel = new NewChatViewModel(

apps/desktop/ArcChat.Desktop/ArcChat.Desktop.csproj

@@ -29,7 +29,11 @@
     <ProjectReference Include="..\..\..\packages\agent-core\ArcChat.Agent\ArcChat.Agent.csproj" />
     <ProjectReference Include="..\..\..\packages\local-persistence\ArcChat.LocalPersistence\ArcChat.LocalPersistence.csproj" />
     <ProjectReference Include="..\..\..\packages\local-services\ArcChat.LocalServices\ArcChat.LocalServices.csproj" />
+    <ProjectReference Include="..\..\..\packages\model-providers\ArcChat.ModelProviders.Anthropic\ArcChat.ModelProviders.Anthropic.csproj" />
     <ProjectReference Include="..\..\..\packages\model-providers\ArcChat.ModelProviders.Core\ArcChat.ModelProviders.Core.csproj" />
+    <ProjectReference Include="..\..\..\packages\model-providers\ArcChat.ModelProviders.GenericOpenAi\ArcChat.ModelProviders.GenericOpenAi.csproj" />
+    <ProjectReference Include="..\..\..\packages\model-providers\ArcChat.ModelProviders.Google\ArcChat.ModelProviders.Google.csproj" />
+    <ProjectReference Include="..\..\..\packages\model-providers\ArcChat.ModelProviders.OpenAi\ArcChat.ModelProviders.OpenAi.csproj" />
     <ProjectReference Include="..\..\..\packages\net-core\ArcChat.Net\ArcChat.Net.csproj" />
     <ProjectReference Include="..\..\..\tools\ArcChat.IconCodegen\ArcChat.IconCodegen.csproj" OutputItemType="Analyzer" ReferenceOutputAssembly="false" PrivateAssets="all" />
   </ItemGroup>

apps/desktop/ArcChat.Desktop/Composition/ServiceCollectionExtensions.cs

@@ -12,7 +12,11 @@
 using ArcChat.Desktop.ViewModels;
 using ArcChat.LocalPersistence;
 using ArcChat.LocalPersistence.Repositories;
+using ArcChat.ModelProviders.Anthropic;
 using ArcChat.ModelProviders.Core;
+using ArcChat.ModelProviders.GenericOpenAi;
+using ArcChat.ModelProviders.Google;
+using ArcChat.ModelProviders.OpenAi;
 using ArcChat.Net.Factory;
 using Microsoft.Extensions.DependencyInjection;
 using ObservableSettingsRepository = ArcChat.LocalServices.Settings.SettingsRepository;
@@ -37,7 +41,8 @@ private static void AddCoreServices(IServiceCollection services)
         _ = services.AddSingleton<IConversationRepository>(provider => provider.GetRequiredService<ArcChatDatabase>().Conversations);
         _ = services.AddSingleton<IMessageRepository>(provider => provider.GetRequiredService<ArcChatDatabase>().Messages);
         _ = services.AddSingleton<PersistenceSettingsRepository>(provider => provider.GetRequiredService<ArcChatDatabase>().Settings);
-        _ = services.AddSingleton<IChatProviderRegistry>(_ => ModelProviderCoreDefaults.CreateRegistry());
+        AddChatProviders(services);
+        _ = services.AddArcChatProviders();
         _ = services.AddSingleton<IAgentRuntime>(provider => new AgentRuntime(provider.GetRequiredService<IChatProviderRegistry>()));
         _ = services.AddSingleton<IConversationTitler, ConversationTitler>();
         _ = services.AddSingleton<IContextSummarizer, ContextSummarizer>();
@@ -53,6 +58,18 @@ private static void AddCoreServices(IServiceCollection services)
         _ = services.AddSingleton<ILocaleService>(_ => LocaleService.FromDirectory(CreateLocaleDirectory(), CultureInfo.CurrentUICulture.Name));
     }
 
+    private static void AddChatProviders(IServiceCollection services)
+    {
+        _ = services.AddSingleton<IChatProvider>(provider =>
+            new OpenAiProvider(provider.GetRequiredService<INetCoreFactory>().GetClient(NetClientProfileNames.Streaming)));
+        _ = services.AddSingleton<IChatProvider>(provider =>
+            new AnthropicProvider(provider.GetRequiredService<INetCoreFactory>().GetClient(NetClientProfileNames.Streaming)));
+        _ = services.AddSingleton<IChatProvider>(provider =>
+            new GoogleProvider(provider.GetRequiredService<INetCoreFactory>().GetClient(NetClientProfileNames.Streaming)));
+        _ = services.AddSingleton<IChatProvider>(provider =>
+            new GenericOpenAiProvider(provider.GetRequiredService<INetCoreFactory>().GetClient(NetClientProfileNames.Streaming)));
+    }
+
     private static void AddFeatureViewModels(IServiceCollection services)
     {
         _ = services.AddTransient(provider => new SettingsViewModel(

docs/coverage/providers-live-demo.md

@@ -0,0 +1,45 @@
+# NC05 Provider Live Demo Evidence
+
+NC05 lands the chat-provider SPI and the four reference chat providers required before later provider waves:
+OpenAI, Anthropic, Google Gemini, and GenericOpenAI-compatible endpoints.
+
+## Offline Contract Evidence
+
+The provider contract suites stream recorded fixtures without network access:
+
+| Provider | Fixture | Test evidence |
+| --- | --- | --- |
+| OpenAI | `packages/model-providers/ArcChat.ModelProviders.OpenAi.Tests/Resources/openai-stream-tools-vision.ndjson` | `OpenAiProviderTests.StreamsOpenAiFixtureWithVisionToolsAndReasoning` |
+| Anthropic | `packages/model-providers/ArcChat.ModelProviders.Anthropic.Tests/Resources/anthropic-messages-tools-vision.ndjson` | `AnthropicProviderTests.StreamsAnthropicFixtureWithVisionToolsAndThinking` |
+| Google | `packages/model-providers/ArcChat.ModelProviders.Google.Tests/Resources/google-stream-tools-vision.ndjson` | `GoogleProviderTests.StreamsGoogleFixtureWithVisionToolsAndSafetySettings` |
+| GenericOpenAI | `packages/model-providers/ArcChat.ModelProviders.GenericOpenAi.Tests/Resources/vllm-stream-tools-vision.ndjson`; `packages/model-providers/ArcChat.ModelProviders.GenericOpenAi.Tests/Resources/lmstudio-chat-stream.ndjson` | `GenericOpenAiProviderTests.StreamsVllmCompatibleFixtureWithConfiguredEndpointVisionAndTools`; `GenericOpenAiProviderTests.StreamsLmStudioFixtureAgainstBaseUriWithoutVersionSegment` |
+
+## Desktop Selection Evidence
+
+`SettingsDefaults.Create()` now seeds selectable provider configs for OpenAI, Anthropic, Google, and GenericOpenAI. `ArcChat.Desktop` registers all four providers with the streaming HTTP profile, so `AgentRuntime` resolves the selected `ModelConfig.ProviderName` directly from the desktop composition root.
+
+Automated coverage:
+
+```text
+dotnet test apps/desktop/ArcChat.Desktop.UiTests/ArcChat.Desktop.UiTests.csproj -m:1 /p:TreatWarningsAsErrors=true
+```
+
+Result: passed, 46 tests. `NewChatViewModelTests.NewChatProviderPickerIncludesReferenceProviders` verifies the provider picker contains OpenAI, Anthropic, Google, and GenericOpenAI with at least one selectable model each.
+
+## Live Demo Procedure
+
+Live provider streaming is enabled through provider-specific environment variables until NC15 moves API keys into the OS keychain:
+
+```powershell
+$env:OPENAI_API_KEY = "<developer key>"
+$env:ANTHROPIC_API_KEY = "<developer key>"
+$env:GOOGLE_API_KEY = "<developer key>"
+$env:GENERIC_OPENAI_BASE_URL = "http://localhost:8000"
+$env:GENERIC_OPENAI_API_KEY = "<optional endpoint token>"
+$env:MSBUILDDISABLENODEREUSE = "1"
+dotnet run --project apps/desktop/ArcChat.Desktop/ArcChat.Desktop.csproj
+```
+
+Manual path: New Chat -> provider picker -> choose OpenAI, Anthropic, Google, or GenericOpenAI -> send a prompt -> verify streamed assistant response.
+
+Live execution status for this automated run: not executed because no developer provider key was supplied in the environment. The desktop wiring and stream behavior are covered by the offline contract and UI tests above.

docs/coverage/settings-schema.md

@@ -15,6 +15,10 @@ NC02 lands the shared protocol DTOs, the local SQLite v1 schema, and repository
 | Sync store | `SyncSnapshot`, `SyncProviderConfig` | `SyncMeta`, `SyncBackup`, and generic JSON table store | `ProtocolRoundTripTests.ProviderSettingsAndSyncDtosPreserveOpaqueExtraFields`; `MigrationAndSchemaTests.JsonBackedTablesRoundTripEveryAuxiliaryTable` |
 | Mask/plugin/MCP/artifact seeds | `Mask`, `Plugin`, `PluginManifest`, `McpConfigData`, `McpRequestMessage`, `McpResponseMessage`, `McpTool`, `HtmlArtifactPreview`, `ArcTool` | `Mask`, `Plugin`, `McpServer`, `HtmlArtifactPreview`, `ToolCall`, `PromptSeed`, `KeychainRef` tables | `ProtocolRoundTripTests.MaskPluginMcpAndArtifactDtosRoundTrip`; `MigrationAndSchemaTests.JsonBackedTablesRoundTripEveryAuxiliaryTable` |
 
+## NC05 Provider Settings Evidence
+
+NC05 extends `SettingsDefaults.Create()` with selectable provider configs for OpenAI, Anthropic, Google, and GenericOpenAI. The seeded `ProviderConfig` rows include endpoint base URLs and model descriptors. `NewChatViewModelTests.NewChatProviderPickerIncludesReferenceProviders` verifies the desktop provider picker exposes all four NC05 providers and at least one model for each provider.
+
 ## Store Metadata
 
 | Source | Store key | Version | Migrations found | Owner |

packages/agent-core/ArcChat.Agent.Tests/AgentRuntimeTests.cs

@@ -124,12 +124,12 @@ public SequenceProvider(params ChatEvent[] events)
             this.events = events;
         }
 
-        public string Id => "OpenAI";
+        public ProviderId Id => new ProviderId("OpenAI");
 
-        public bool SupportsVision => false;
+        public ChatProviderCapabilities Capabilities => ChatProviderCapabilities.Streaming;
 
         public async IAsyncEnumerable<ChatEvent> StreamAsync(
-            ChatProviderRequest request,
+            ChatRequest request,
             [EnumeratorCancellation] CancellationToken cancellationToken = default)
         {
             foreach (ChatEvent chatEvent in this.events)
@@ -139,18 +139,23 @@ public async IAsyncEnumerable<ChatEvent> StreamAsync(
                 yield return chatEvent;
             }
         }
+
+        public Task<ImmutableArray<ModelDescriptor>> ListModelsAsync(CancellationToken cancellationToken = default)
+        {
+            return Task.FromResult(ImmutableArray<ModelDescriptor>.Empty);
+        }
     }
 
     private sealed class RetryProvider : IChatProvider
     {
         public int Attempts { get; private set; }
 
-        public string Id => "OpenAI";
+        public ProviderId Id => new ProviderId("OpenAI");
 
-        public bool SupportsVision => false;
+        public ChatProviderCapabilities Capabilities => ChatProviderCapabilities.Streaming;
 
         public async IAsyncEnumerable<ChatEvent> StreamAsync(
-            ChatProviderRequest request,
+            ChatRequest request,
             [EnumeratorCancellation] CancellationToken cancellationToken = default)
         {
             this.Attempts++;
@@ -161,23 +166,33 @@ public async IAsyncEnumerable<ChatEvent> StreamAsync(
             }
 
             cancellationToken.ThrowIfCancellationRequested();
-            yield return new MessageDelta(request.ConversationId, request.MessageId, "ok");
-            yield return new ChatFinished(request.ConversationId, request.MessageId, "stop");
+            yield return new MessageDelta(request.Extra.ConversationId, request.Extra.MessageId, "ok");
+            yield return new ChatFinished(request.Extra.ConversationId, request.Extra.MessageId, "stop");
+        }
+
+        public Task<ImmutableArray<ModelDescriptor>> ListModelsAsync(CancellationToken cancellationToken = default)
+        {
+            return Task.FromResult(ImmutableArray<ModelDescriptor>.Empty);
         }
     }
 
     private sealed class SlowProvider : IChatProvider
     {
-        public string Id => "OpenAI";
+        public ProviderId Id => new ProviderId("OpenAI");
 
-        public bool SupportsVision => false;
+        public ChatProviderCapabilities Capabilities => ChatProviderCapabilities.Streaming;
 
         public async IAsyncEnumerable<ChatEvent> StreamAsync(
-            ChatProviderRequest request,
+            ChatRequest request,
             [EnumeratorCancellation] CancellationToken cancellationToken = default)
         {
             await Task.Delay(TimeSpan.FromSeconds(5), cancellationToken).ConfigureAwait(false);
-            yield return new MessageDelta(request.ConversationId, request.MessageId, "late");
+            yield return new MessageDelta(request.Extra.ConversationId, request.Extra.MessageId, "late");
+        }
+
+        public Task<ImmutableArray<ModelDescriptor>> ListModelsAsync(CancellationToken cancellationToken = default)
+        {
+            return Task.FromResult(ImmutableArray<ModelDescriptor>.Empty);
         }
     }
 }

packages/agent-core/ArcChat.Agent.Tests/ConversationMetadataTests.cs

@@ -30,8 +30,8 @@ public async Task ConversationTitlerUsesProviderOutput()
         string title = await titler.GenerateTitleAsync(conversation, CancellationToken.None).ConfigureAwait(true);
 
         _ = title.Should().Be("Neural roadmap");
-        ChatProviderRequest request = provider.Requests.Should().ContainSingle().Subject;
-        Message lastMessage = request.Messages[request.Messages.Count - 1];
+        ChatRequest request = provider.Requests.Should().ContainSingle().Subject;
+        Message lastMessage = request.History[request.History.Length - 1];
         _ = lastMessage.Role.Should().Be(MessageRole.User);
         _ = ConversationPromptRunner.ExtractText(lastMessage).Should().Be(ConversationTitler.TopicPrompt);
     }
@@ -57,8 +57,8 @@ public async Task ContextSummarizerCollapsesLongHistoryToBoundedMemoryPrompt()
 
         _ = Encoding.UTF8.GetByteCount(summarized.MemoryPrompt).Should().BeLessThanOrEqualTo(ContextSummarizer.MaxSummaryUtf8Bytes);
         _ = summarized.LastSummarizeIndex.Should().Be(500);
-        ChatProviderRequest request = provider.Requests.Should().ContainSingle().Subject;
-        Message lastMessage = request.Messages[request.Messages.Count - 1];
+        ChatRequest request = provider.Requests.Should().ContainSingle().Subject;
+        Message lastMessage = request.History[request.History.Length - 1];
         _ = lastMessage.Role.Should().Be(MessageRole.System);
         _ = ConversationPromptRunner.ExtractText(lastMessage).Should().Be(ContextSummarizer.SummaryPrompt);
     }
@@ -74,22 +74,22 @@ private static Message[] CreateMessages(int count)
             .ToArray();
     }
 
-    private static Func<ChatProviderRequest, CancellationToken, IAsyncEnumerable<ChatEvent>> CompletedText(string text)
+    private static Func<ChatRequest, CancellationToken, IAsyncEnumerable<ChatEvent>> CompletedText(string text)
     {
         return (request, cancellationToken) => StreamCompletedText(request, text, cancellationToken);
     }
 
     private static async IAsyncEnumerable<ChatEvent> StreamCompletedText(
-        ChatProviderRequest request,
+        ChatRequest request,
         string text,
         [EnumeratorCancellation] CancellationToken cancellationToken = default)
     {
         await Task.Delay(1, cancellationToken).ConfigureAwait(true);
         yield return new MessageCompleted(
-            request.ConversationId,
-            request.MessageId,
-            Message.Text(request.MessageId, MessageRole.Assistant, text, "0"));
-        yield return new ChatFinished(request.ConversationId, request.MessageId, "stop");
+            request.Extra.ConversationId,
+            request.Extra.MessageId,
+            Message.Text(request.Extra.MessageId, MessageRole.Assistant, text, "0"));
+        yield return new ChatFinished(request.Extra.ConversationId, request.Extra.MessageId, "stop");
     }
 
     [SuppressMessage("StyleCop.CSharp.ReadabilityRules", "SA1101:PrefixLocalCallsWithThis", Justification = "Record with-expressions use member assignment syntax.")]
@@ -120,23 +120,28 @@ private static Conversation CreateConversation(string topic, params Message[] me
 
     private sealed class ScriptedProvider : IChatProvider
     {
-        private readonly Func<ChatProviderRequest, CancellationToken, IAsyncEnumerable<ChatEvent>> streamFactory;
+        private readonly Func<ChatRequest, CancellationToken, IAsyncEnumerable<ChatEvent>> streamFactory;
 
-        public ScriptedProvider(Func<ChatProviderRequest, CancellationToken, IAsyncEnumerable<ChatEvent>> streamFactory)
+        public ScriptedProvider(Func<ChatRequest, CancellationToken, IAsyncEnumerable<ChatEvent>> streamFactory)
         {
             this.streamFactory = streamFactory;
         }
 
-        public List<ChatProviderRequest> Requests { get; } = new List<ChatProviderRequest>();
+        public List<ChatRequest> Requests { get; } = new List<ChatRequest>();
 
-        public string Id => "OpenAI";
+        public ProviderId Id => new ProviderId("OpenAI");
 
-        public bool SupportsVision => false;
+        public ChatProviderCapabilities Capabilities => ChatProviderCapabilities.Streaming;
 
-        public IAsyncEnumerable<ChatEvent> StreamAsync(ChatProviderRequest request, CancellationToken cancellationToken = default)
+        public IAsyncEnumerable<ChatEvent> StreamAsync(ChatRequest request, CancellationToken cancellationToken = default)
         {
             this.Requests.Add(request);
             return this.streamFactory(request, cancellationToken);
         }
+
+        public Task<ImmutableArray<ModelDescriptor>> ListModelsAsync(CancellationToken cancellationToken = default)
+        {
+            return Task.FromResult(ImmutableArray<ModelDescriptor>.Empty);
+        }
     }
 }