.NET: Simplify store=false scenario for responses (#4124)

* Simplify store=false scenario for responses

* Mark AsIChatClientWithStoredOutputDisabled as Experimental

dotnet/samples/Directory.Build.props

@@ -7,6 +7,7 @@
     <IsAotCompatible>false</IsAotCompatible>
     <TargetFrameworks>net10.0;net472</TargetFrameworks>
     <UserSecretsId>5ee045b0-aea3-4f08-8d31-32d1a6f8fed0</UserSecretsId>
+    <NoWarn>$(NoWarn);MAAI001</NoWarn>
   </PropertyGroup>
 
   <ItemGroup>

dotnet/samples/GettingStarted/AgentProviders/Agent_With_AzureOpenAIResponses/Program.cs

@@ -5,6 +5,7 @@
 using Azure.AI.OpenAI;
 using Azure.Identity;
 using Microsoft.Agents.AI;
+using Microsoft.Extensions.AI;
 using OpenAI.Responses;
 
 var endpoint = Environment.GetEnvironmentVariable("AZURE_OPENAI_ENDPOINT") ?? throw new InvalidOperationException("AZURE_OPENAI_ENDPOINT is not set.");
@@ -21,3 +22,16 @@ AIAgent agent = new AzureOpenAIClient(
 
 // Invoke the agent and output the text result.
 Console.WriteLine(await agent.RunAsync("Tell me a joke about a pirate."));
+
+// Create a responses based agent with "store"=false.
+// This means that chat history is managed locally by Agent Framework
+// instead of being stored in the service (default).
+AIAgent agentStoreFalse = new AzureOpenAIClient(
+    new Uri(endpoint),
+    new DefaultAzureCredential())
+     .GetResponsesClient(deploymentName)
+     .AsIChatClientWithStoredOutputDisabled()
+     .AsAIAgent(instructions: "You are good at telling jokes.", name: "Joker");
+
+// Invoke the agent and output the text result.
+Console.WriteLine(await agentStoreFalse.RunAsync("Tell me a joke about a pirate."));

dotnet/src/Microsoft.Agents.AI.OpenAI/Extensions/OpenAIResponseClientExtensions.cs

@@ -92,4 +92,23 @@ public static class OpenAIResponseClientExtensions
 
         return new ChatClientAgent(chatClient, options, loggerFactory, services);
     }
+
+    /// <summary>
+    /// Gets an <see cref="IChatClient"/> for use with this <see cref="ResponsesClient"/> that does not store responses for later retrieval.
+    /// </summary>
+    /// <remarks>
+    /// This corresponds to setting the "store" property in the JSON representation to false.
+    /// </remarks>
+    /// <param name="responseClient">The client.</param>
+    /// <returns>An <see cref="IChatClient"/> that can be used to converse via the <see cref="ResponsesClient"/> that does not store responses for later retrieval.</returns>
+    /// <exception cref="ArgumentNullException"><paramref name="responseClient"/> is <see langword="null"/>.</exception>
+    [Experimental(DiagnosticIds.Experiments.AgentsAIExperiments)]
+    public static IChatClient AsIChatClientWithStoredOutputDisabled(this ResponsesClient responseClient)
+    {
+        return Throw.IfNull(responseClient)
+            .AsIChatClient()
+            .AsBuilder()
+            .ConfigureOptions(x => x.RawRepresentationFactory = _ => new CreateResponseOptions() { StoredOutputEnabled = false })
+            .Build();
+    }
 }

dotnet/tests/Directory.Build.props

@@ -8,7 +8,7 @@
     <IsAotCompatible>false</IsAotCompatible>
     <TargetFrameworks>net10.0;net472</TargetFrameworks>
     <UserSecretsId>b7762d10-e29b-4bb1-8b74-b6d69a667dd4</UserSecretsId>
-    <NoWarn>$(NoWarn);Moq1410;xUnit2023</NoWarn>
+    <NoWarn>$(NoWarn);Moq1410;xUnit2023;MAAI001</NoWarn>
   </PropertyGroup>
 
   <ItemGroup>

dotnet/tests/Microsoft.Agents.AI.OpenAI.UnitTests/Extensions/OpenAIResponseClientExtensionsTests.cs

@@ -259,6 +259,38 @@ public sealed class OpenAIResponseClientExtensionsTests
         Assert.Same(serviceProvider, GetFunctionInvocationServices(functionInvokingClient));
     }
 
+    /// <summary>
+    /// Verify that AsIChatClientWithStoredOutputDisabled throws ArgumentNullException when client is null.
+    /// </summary>
+    [Fact]
+    public void AsIChatClientWithStoredOutputDisabled_WithNullClient_ThrowsArgumentNullException()
+    {
+        // Act & Assert
+        var exception = Assert.Throws<ArgumentNullException>(() =>
+            ((ResponsesClient)null!).AsIChatClientWithStoredOutputDisabled());
+
+        Assert.Equal("responseClient", exception.ParamName);
+    }
+
+    /// <summary>
+    /// Verify that AsIChatClientWithStoredOutputDisabled wraps the original ResponsesClient,
+    /// which remains accessible via the service chain.
+    /// </summary>
+    [Fact]
+    public void AsIChatClientWithStoredOutputDisabled_InnerResponsesClientIsAccessible()
+    {
+        // Arrange
+        var responseClient = new TestOpenAIResponseClient();
+
+        // Act
+        var chatClient = responseClient.AsIChatClientWithStoredOutputDisabled();
+
+        // Assert - the inner ResponsesClient should be accessible via GetService
+        var innerClient = chatClient.GetService<ResponsesClient>();
+        Assert.NotNull(innerClient);
+        Assert.Same(responseClient, innerClient);
+    }
+
     /// <summary>
     /// A simple test IServiceProvider implementation for testing.
     /// </summary>