Migrate from Anthropic.SDK to official Anthropic package (#1083)

Co-authored-by: copilot-swe-agent[bot] <[email protected]>
Co-authored-by: stephentoub <[email protected]>

Author: Copilot

Directory.Packages.props

@@ -59,7 +59,7 @@
 
   <!-- Testing dependencies -->
   <ItemGroup>
-    <PackageVersion Include="Anthropic.SDK" Version="5.8.0" />
+    <PackageVersion Include="Anthropic" Version="11.0.0" />
     <PackageVersion Include="coverlet.collector" Version="6.0.4">
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
       <PrivateAssets>all</PrivateAssets>

samples/ChatWithTools/ChatWithTools.csproj

@@ -14,7 +14,6 @@
   <ItemGroup>
     <PackageReference Include="Microsoft.Extensions.AI" />
     <PackageReference Include="Microsoft.Extensions.AI.OpenAI" />
-    <PackageReference Include="Anthropic.SDK" />
     <PackageReference Include="OpenTelemetry.Exporter.OpenTelemetryProtocol" />
     <PackageReference Include="OpenTelemetry.Instrumentation.Http" />
   </ItemGroup>

samples/QuickstartClient/Program.cs

@@ -1,4 +1,4 @@
-using Anthropic.SDK;
+using Anthropic;
 using Microsoft.Extensions.AI;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.Hosting;
@@ -41,8 +41,8 @@
     Console.WriteLine($"Connected to server with tools: {tool.Name}");
 }
 
-using var anthropicClient = new AnthropicClient(new APIAuthentication(builder.Configuration["ANTHROPIC_API_KEY"]))
-    .Messages
+using var anthropicClient = new AnthropicClient(new() { APIKey = builder.Configuration["ANTHROPIC_API_KEY"] })
+    .AsIChatClient("claude-haiku-4-5-20251001")
     .AsBuilder()
     .UseFunctionInvocation()
     .Build();

samples/QuickstartClient/QuickstartClient.csproj

@@ -17,7 +17,7 @@
     </ItemGroup>
 
     <ItemGroup>
-        <PackageReference Include="Anthropic.SDK" />
+        <PackageReference Include="Anthropic" />
         <PackageReference Include="Microsoft.Extensions.Hosting" />
         <PackageReference Include="Microsoft.Extensions.AI" />
     </ItemGroup>