Add Microsoft.Extensions.AI support

.editorconfig

@@ -21,6 +21,7 @@ tab_width = 4
 end_of_line = crlf
 insert_final_newline = true
 
+dotnet_diagnostic.CA1510.severity = none  # Use ArgumentNullException throw helper
 dotnet_diagnostic.IDE0060.severity = none # Caused by resource with no methods and no subresources
 dotnet_diagnostic.IDE1006.severity = none # Some names may not match up with C# conventions
 dotnet_diagnostic.IDE0290.severity = none # Don't prefer primary constructors

README.md

@@ -156,6 +156,33 @@ await foreach (var message in client.Messages.CreateStreaming(parameters))
 }
 ```
 
+## `IChatClient`
+
+The SDK provides an implementation of the `IChatClient` interface from the `Microsoft.Extensions.AI.Abstractions` library.
+This enables `AnthropicClient` (and `Anthropic.Services.IBetaService`) to be used with other libraries that integrate with
+these core abstractions. For example, tools in the MCP C# SDK (`ModelContextProtocol`) library can be used directly with an `AnthropicClient`
+exposed via `IChatClient`.
+
+```csharp
+using Anthropic;
+using Microsoft.Extensions.AI;
+using ModelContextProtocol.Client;
+
+// Configured using the ANTHROPIC_API_KEY, ANTHROPIC_AUTH_TOKEN and ANTHROPIC_BASE_URL environment variables
+IChatClient chatClient = client.AsIChatClient("claude-haiku-4-5")
+    .AsBuilder()
+    .UseFunctionInvocation()
+    .Build();
+
+// Using McpClient from the MCP C# SDK
+McpClient learningServer = await McpClient.CreateAsync(
+    new HttpClientTransport(new() { Endpoint = new("https://learn.microsoft.com/api/mcp") }));
+
+ChatOptions options = new() { Tools = [.. await learningServer.ListToolsAsync()] };
+
+Console.WriteLine(await chatClient.GetResponseAsync("Tell me about IChatClient", options));
+```
+
 ## Binary responses
 
 The SDK defines methods that return binary responses, which are used for API responses that shouldn't necessarily be parsed, like non-JSON data.

examples/ChatClientExample/ChatClientExample.csproj

@@ -0,0 +1,12 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <ItemGroup>
+    <ProjectReference Include="..\..\src\Anthropic\Anthropic.csproj" />
+    <PackageReference Include="Microsoft.Extensions.AI" Version="10.0.0" />
+  </ItemGroup>
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+</Project>

examples/ChatClientExample/Program.cs

@@ -0,0 +1,32 @@
+using Anthropic;
+using Microsoft.Extensions.AI;
+
+// Configured using the ANTHROPIC_API_KEY, ANTHROPIC_AUTH_TOKEN and ANTHROPIC_BASE_URL environment variables
+IChatClient chatClient = new AnthropicClient()
+    .AsIChatClient("claude-haiku-4-5")
+    .AsBuilder()
+    .UseFunctionInvocation()
+    .Build();
+
+ChatOptions options = new()
+{
+    Tools =
+    [
+        AIFunctionFactory.Create(
+            () => Environment.UserName,
+            "get_current_user_name",
+            "Gets the current user's name."
+        ),
+    ],
+};
+
+await foreach (
+    var update in chatClient.GetStreamingResponseAsync(
+        "Write a Haiku about the current user's name",
+        options
+    )
+)
+{
+    Console.Write(update);
+}
+Console.WriteLine();