Address comments

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

dotnet/src/Microsoft.Agents.AI.Foundry.Hosting/AgentFrameworkResponseHandler.cs

@@ -297,6 +297,7 @@ public class AgentFrameworkResponseHandler : ResponseHandler
             var agent = this._serviceProvider.GetKeyedService<AIAgent>(agentName);
             if (agent is not null)
             {
+                FoundryHostingExtensions.TryApplyUserAgent(agent);
                 return FoundryHostingExtensions.ApplyOpenTelemetry(agent);
             }
 
@@ -310,12 +311,13 @@ public class AgentFrameworkResponseHandler : ResponseHandler
         var defaultAgent = this._serviceProvider.GetService<AIAgent>();
         if (defaultAgent is not null)
         {
+            FoundryHostingExtensions.TryApplyUserAgent(defaultAgent);
             return FoundryHostingExtensions.ApplyOpenTelemetry(defaultAgent);
         }
 
         var errorMessage = string.IsNullOrEmpty(agentName)
             ? "No agent name specified in the request (via agent.name or metadata[\"entity_id\"]) and no default AIAgent is registered."
-            : $"Agent '{agentName}' not found. Ensure it is registered via AddAIAgent(\"{agentName}\", ...) or as a default AIAgent.";
+            : $"Agent '{agentName}' not found. Ensure it is registered via AddFoundryResponses(services, agent) or services.AddKeyedSingleton<AIAgent>(\"{agentName}\", ...).";
 
         throw new InvalidOperationException(errorMessage);
     }
@@ -352,7 +354,7 @@ public class AgentFrameworkResponseHandler : ResponseHandler
 
         var errorMessage = string.IsNullOrEmpty(agentName)
             ? "No agent name specified in the request (via agent.name or metadata[\"entity_id\"]) and no default AgentSessionStore is registered."
-            : $"Agent '{agentName}' not found. Ensure it is registered via AddAIAgent(\"{agentName}\", ...) or as a default AgentSessionStore.";
+            : $"AgentSessionStore for agent '{agentName}' not found. Ensure it is registered via AddFoundryResponses(services, agent, agentSessionStore) or services.AddKeyedSingleton<AgentSessionStore>(\"{agentName}\", ...).";
 
         throw new InvalidOperationException(errorMessage);
     }

dotnet/src/Microsoft.Agents.AI.Foundry.Hosting/DelegatingResponsesClient.cs

@@ -0,0 +1,113 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System;
+using System.ClientModel;
+using System.ClientModel.Primitives;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using OpenAI;
+using OpenAI.Responses;
+
+#pragma warning disable OPENAI001, SCME0001
+
+namespace Microsoft.Agents.AI.Foundry.Hosting;
+
+/// <summary>
+/// A <see cref="ResponsesClient"/> subclass that delegates every protocol-level request to a
+/// wrapped <see cref="ResponsesClient"/>. Before each call, a
+/// <see cref="HostedAgentUserAgentPolicy"/> is added to the per-call
+/// <see cref="RequestOptions"/> so the wrapped client's pipeline appends the hosted-agent
+/// <c>User-Agent</c> segment on the wire.
+/// </summary>
+/// <remarks>
+/// <para>
+/// The streaming overloads MEAI binds via reflection (<c>internal CreateResponseStreamingAsync(CreateResponseOptions, RequestOptions)</c>
+/// and <c>internal GetResponseStreamingAsync(GetResponseOptions, RequestOptions)</c>) bottom out
+/// in calls to the public-virtual non-streaming protocol overloads on <see langword="this"/>. Overriding those
+/// non-streaming overloads is therefore sufficient to intercept both streaming and non-streaming traffic.
+/// </para>
+/// <para>
+/// The base pipeline supplied to <see cref="ResponsesClient(ClientPipeline, OpenAIClientOptions)"/>
+/// is a dummy pipeline whose terminal transport throws if invoked. Every override on this class
+/// delegates to the inner client BEFORE any code path reaches <see cref="ResponsesClient.Pipeline"/>, so the dummy is
+/// never expected to run; the throwing transport surfaces any unexpected escape route loudly.
+/// </para>
+/// </remarks>
+internal sealed class DelegatingResponsesClient : ResponsesClient
+{
+    private readonly ResponsesClient _inner;
+
+    public DelegatingResponsesClient(ResponsesClient inner)
+        : base(BuildDummyPipeline(), new OpenAIClientOptions { Endpoint = inner?.Endpoint })
+    {
+        this._inner = inner ?? throw new ArgumentNullException(nameof(inner));
+    }
+
+    public override async Task<ClientResult> CreateResponseAsync(BinaryContent content, RequestOptions? options = null)
+        => await this._inner.CreateResponseAsync(content, AddUserAgentPolicy(options)).ConfigureAwait(false);
+
+    public override ClientResult CreateResponse(BinaryContent content, RequestOptions? options = null)
+        => this._inner.CreateResponse(content, AddUserAgentPolicy(options));
+
+    public override async Task<ClientResult> GetResponseAsync(string responseId, IEnumerable<IncludedResponseProperty>? include, bool? stream, int? startingAfter, bool? includeObfuscation, RequestOptions options)
+        => await this._inner.GetResponseAsync(responseId, include, stream, startingAfter, includeObfuscation, AddUserAgentPolicy(options)).ConfigureAwait(false);
+
+    public override ClientResult GetResponse(string responseId, IEnumerable<IncludedResponseProperty>? include, bool? stream, int? startingAfter, bool? includeObfuscation, RequestOptions options)
+        => this._inner.GetResponse(responseId, include, stream, startingAfter, includeObfuscation, AddUserAgentPolicy(options));
+
+    public override async Task<ClientResult> DeleteResponseAsync(string responseId, RequestOptions options)
+        => await this._inner.DeleteResponseAsync(responseId, AddUserAgentPolicy(options)).ConfigureAwait(false);
+
+    public override ClientResult DeleteResponse(string responseId, RequestOptions options)
+        => this._inner.DeleteResponse(responseId, AddUserAgentPolicy(options));
+
+    public override async Task<ClientResult> CancelResponseAsync(string responseId, RequestOptions options)
+        => await this._inner.CancelResponseAsync(responseId, AddUserAgentPolicy(options)).ConfigureAwait(false);
+
+    public override ClientResult CancelResponse(string responseId, RequestOptions options)
+        => this._inner.CancelResponse(responseId, AddUserAgentPolicy(options));
+
+    public override async Task<ClientResult> GetInputTokenCountAsync(string contentType, BinaryContent content, RequestOptions? options = null)
+        => await this._inner.GetInputTokenCountAsync(contentType, content, AddUserAgentPolicy(options)).ConfigureAwait(false);
+
+    public override ClientResult GetInputTokenCount(string contentType, BinaryContent content, RequestOptions? options = null)
+        => this._inner.GetInputTokenCount(contentType, content, AddUserAgentPolicy(options));
+
+    public override async Task<ClientResult> CompactResponseAsync(string contentType, BinaryContent content, RequestOptions? options = null)
+        => await this._inner.CompactResponseAsync(contentType, content, AddUserAgentPolicy(options)).ConfigureAwait(false);
+
+    public override ClientResult CompactResponse(string contentType, BinaryContent content, RequestOptions? options = null)
+        => this._inner.CompactResponse(contentType, content, AddUserAgentPolicy(options));
+
+    public override async Task<ClientResult> GetResponseInputItemCollectionPageAsync(string responseId, int? limit, string order, string after, string before, RequestOptions options)
+        => await this._inner.GetResponseInputItemCollectionPageAsync(responseId, limit, order, after, before, AddUserAgentPolicy(options)).ConfigureAwait(false);
+
+    public override ClientResult GetResponseInputItemCollectionPage(string responseId, int? limit, string order, string after, string before, RequestOptions options)
+        => this._inner.GetResponseInputItemCollectionPage(responseId, limit, order, after, before, AddUserAgentPolicy(options));
+
+    private static RequestOptions AddUserAgentPolicy(RequestOptions? options)
+    {
+        options ??= new RequestOptions();
+        options.AddPolicy(HostedAgentUserAgentPolicy.Instance, PipelinePosition.PerCall);
+        return options;
+    }
+
+    private static ClientPipeline BuildDummyPipeline()
+    {
+        var options = new ClientPipelineOptions
+        {
+            Transport = new ThrowingTransport(),
+        };
+        return ClientPipeline.Create(options, default, default, default);
+    }
+
+    private sealed class ThrowingTransport : PipelineTransport
+    {
+        private const string Message =
+            "DelegatingResponsesClient transport invoked bypassed the override-and-delegate design. This exception should be unreachable and should never be thrown following the correct usage of DelegatingResponsesClient.";
+
+        protected override PipelineMessage CreateMessageCore() => throw new InvalidOperationException(Message);
+        protected override void ProcessCore(PipelineMessage message) => throw new InvalidOperationException(Message);
+        protected override ValueTask ProcessCoreAsync(PipelineMessage message) => throw new InvalidOperationException(Message);
+    }
+}

dotnet/src/Microsoft.Agents.AI.Foundry.Hosting/HostedAgentUserAgentPolicy.cs

@@ -0,0 +1,84 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System.ClientModel.Primitives;
+using System.Collections.Generic;
+using System.Reflection;
+using System.Threading.Tasks;
+
+namespace Microsoft.Agents.AI.Foundry.Hosting;
+
+/// <summary>
+/// Pipeline policy that appends the hosted-agent <c>User-Agent</c> segment
+/// (e.g. <c>"foundry-hosting/agent-framework-dotnet/{version}"</c>) to outgoing requests.
+/// </summary>
+/// <remarks>
+/// <para>
+/// The supplement value is computed once from the Microsoft.Agents.AI.Foundry.Hosting
+/// assembly's informational version. The policy is idempotent on retries: if the segment
+/// is already present in the <c>User-Agent</c> header, the policy does not append it again.
+/// </para>
+/// <para>
+/// This policy is added at request time (per-call <see cref="PipelinePosition"/>)
+/// by <see cref="DelegatingResponsesClient"/> when invoking the wrapped
+/// <see cref="OpenAI.Responses.ResponsesClient"/>. It is only registered when an agent is
+/// resolved by the Foundry hosting layer.
+/// </para>
+/// </remarks>
+internal sealed class HostedAgentUserAgentPolicy : PipelinePolicy
+{
+    public static HostedAgentUserAgentPolicy Instance { get; } = new HostedAgentUserAgentPolicy();
+
+    private static readonly string s_supplementValue = CreateSupplementValue();
+
+    public override void Process(PipelineMessage message, IReadOnlyList<PipelinePolicy> pipeline, int currentIndex)
+    {
+        AppendHeader(message);
+        ProcessNext(message, pipeline, currentIndex);
+    }
+
+    public override async ValueTask ProcessAsync(PipelineMessage message, IReadOnlyList<PipelinePolicy> pipeline, int currentIndex)
+    {
+        AppendHeader(message);
+        await ProcessNextAsync(message, pipeline, currentIndex).ConfigureAwait(false);
+    }
+
+    private static void AppendHeader(PipelineMessage message)
+    {
+        if (message.Request.Headers.TryGetValue("User-Agent", out var existing) && !string.IsNullOrEmpty(existing))
+        {
+            // Guard against double-append on retries or when the policy
+            // is registered on multiple pipeline positions.
+            if (existing.Contains(s_supplementValue))
+            {
+                return;
+            }
+
+            message.Request.Headers.Set("User-Agent", $"{existing} {s_supplementValue}");
+        }
+        else
+        {
+            message.Request.Headers.Set("User-Agent", s_supplementValue);
+        }
+    }
+
+    private static string CreateSupplementValue()
+    {
+        const string Name = "foundry-hosting/agent-framework-dotnet";
+
+        if (typeof(HostedAgentUserAgentPolicy).Assembly.GetCustomAttribute<AssemblyInformationalVersionAttribute>()?.InformationalVersion is string version)
+        {
+            int pos = version.IndexOf('+');
+            if (pos >= 0)
+            {
+                version = version.Substring(0, pos);
+            }
+
+            if (version.Length > 0)
+            {
+                return $"{Name}/{version}";
+            }
+        }
+
+        return Name;
+    }
+}

dotnet/src/Microsoft.Agents.AI.Foundry.Hosting/ServiceCollectionExtensions.cs

@@ -3,16 +3,15 @@
 using System;
 using System.Diagnostics.CodeAnalysis;
 using System.Reflection;
-using System.Threading.Tasks;
 using Azure.AI.AgentServer.Responses;
 using Azure.Core;
 using Azure.Identity;
-using Microsoft.AspNetCore.Builder;
-using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Routing;
+using Microsoft.Extensions.AI;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.DependencyInjection.Extensions;
 using Microsoft.Shared.DiagnosticIds;
+using OpenAI.Responses;
 
 namespace Microsoft.Agents.AI.Foundry.Hosting;
 
@@ -36,7 +35,7 @@ public static class FoundryHostingExtensions
     /// <para>
     /// Example:
     /// <code>
-    /// builder.AddAIAgent("my-agent", ...);
+    /// builder.Services.AddKeyedSingleton&lt;AIAgent&gt;("my-agent", myAgent);
     /// builder.Services.AddFoundryResponses();
     ///
     /// var app = builder.Build();
@@ -181,13 +180,6 @@ public static class FoundryHostingExtensions
     {
         ArgumentNullException.ThrowIfNull(endpoints);
         endpoints.MapResponsesServer(prefix);
-
-        if (endpoints is IApplicationBuilder app)
-        {
-            // Ensure the middleware is added to the pipeline
-            app.UseMiddleware<AgentFrameworkUserAgentMiddleware>();
-        }
-
         return endpoints;
     }
 
@@ -216,46 +208,85 @@ public static class FoundryHostingExtensions
                     .Build();
     }
 
-    private sealed class AgentFrameworkUserAgentMiddleware(RequestDelegate next)
+    /// <summary>
+    /// Attempts to wrap the agent's underlying <see cref="ResponsesClient"/>
+    /// with a <see cref="DelegatingResponsesClient"/> so every outgoing Responses-API request
+    /// carries the hosted-agent <c>User-Agent</c> segment.
+    /// </summary>
+    /// <remarks>
+    /// <para>
+    /// Best-effort and idempotent. The method is a no-op when:
+    /// <list type="bullet">
+    /// <item><description><paramref name="agent"/> exposes no <see cref="IChatClient"/>;</description></item>
+    /// <item><description>the chat client is not backed by MEAI's internal <c>OpenAIResponsesChatClient</c> (e.g., a non-OpenAI provider or a custom impl);</description></item>
+    /// <item><description>the inner <see cref="ResponsesClient"/> is already a <see cref="DelegatingResponsesClient"/>.</description></item>
+    /// </list>
+    /// </para>
+    /// <para>
+    /// Works for any <see cref="ResponsesClient"/>-derived inner client — both the Foundry-specific
+    /// <see cref="Azure.AI.Extensions.OpenAI.ProjectResponsesClient"/> and the native OpenAI
+    /// <see cref="ResponsesClient"/> obtained from <see cref="OpenAI.OpenAIClient"/>. The wrapper preserves
+    /// the inner client's pipeline (Transport, RetryPolicy, NetworkTimeout, OrganizationId / ProjectId /
+    /// UserAgentApplicationId, custom policies) because every override delegates to the inner instance.
+    /// </para>
+    /// <para>
+    /// Returns the same <paramref name="agent"/> instance unchanged. Mutation happens via
+    /// reflection on MEAI's private <c>_responseClient</c> field; the agent itself is not wrapped.
+    /// </para>
+    /// </remarks>
+    internal static AIAgent TryApplyUserAgent(AIAgent agent)
     {
-        private static readonly string s_userAgentValue = CreateUserAgentValue();
-
-        public async Task InvokeAsync(HttpContext context)
+        var chatClient = agent.GetService<IChatClient>();
+        if (chatClient is null)
         {
-            var headers = context.Request.Headers;
-            var userAgent = headers.UserAgent.ToString();
-
-            if (string.IsNullOrEmpty(userAgent))
-            {
-                headers.UserAgent = s_userAgentValue;
-            }
-            else if (!userAgent.Contains(s_userAgentValue, StringComparison.OrdinalIgnoreCase))
-            {
-                headers.UserAgent = $"{userAgent} {s_userAgentValue}";
-            }
-
-            await next(context).ConfigureAwait(false);
+            return agent;
         }
 
-        private static string CreateUserAgentValue()
+        var meaiType = s_meaiResponsesChatClientType;
+        if (meaiType is null)
         {
-            const string Name = "agent-framework-dotnet";
-
-            if (typeof(AgentFrameworkUserAgentMiddleware).Assembly.GetCustomAttribute<AssemblyInformationalVersionAttribute>()?.InformationalVersion is string version)
-            {
-                int pos = version.IndexOf('+');
-                if (pos >= 0)
-                {
-                    version = version.Substring(0, pos);
-                }
-
-                if (version.Length > 0)
-                {
-                    return $"{Name}/{version}";
-                }
-            }
-
-            return Name;
+            return agent;
         }
+
+        var meaiInstance = chatClient.GetService(meaiType);
+        if (meaiInstance is null)
+        {
+            return agent;
+        }
+
+        var field = s_meaiResponseClientField;
+        if (field is null)
+        {
+            return agent;
+        }
+
+        var current = field.GetValue(meaiInstance) as ResponsesClient;
+        if (current is null or DelegatingResponsesClient)
+        {
+            return agent;
+        }
+
+        field.SetValue(meaiInstance, new DelegatingResponsesClient(current));
+        return agent;
     }
+
+    /// <summary>
+    /// MEAI's internal <c>OpenAIResponsesChatClient</c> type, resolved once via reflection.
+    /// <see langword="null"/> if the type cannot be found (e.g., MEAI version drift).
+    /// </summary>
+    [UnconditionalSuppressMessage("Trimming", "IL2026:RequiresUnreferencedCode",
+        Justification = "MEAI's OpenAIResponsesChatClient is referenced through MicrosoftExtensionsAIResponsesExtensions and survives trimming.")]
+    [UnconditionalSuppressMessage("Trimming", "IL2073:RequiresUnreferencedCode",
+        Justification = "MEAI's OpenAIResponsesChatClient is referenced through MicrosoftExtensionsAIResponsesExtensions and survives trimming.")]
+    private static readonly Type? s_meaiResponsesChatClientType =
+        typeof(MicrosoftExtensionsAIResponsesExtensions).Assembly.GetType("Microsoft.Extensions.AI.OpenAIResponsesChatClient");
+
+    /// <summary>
+    /// MEAI's internal <c>_responseClient</c> field on <c>OpenAIResponsesChatClient</c>,
+    /// resolved once via reflection. <see langword="null"/> if the field cannot be found.
+    /// </summary>
+    [UnconditionalSuppressMessage("Trimming", "IL2080:RequiresDynamicallyAccessedMembers",
+        Justification = "OpenAIResponsesChatClient and its private fields are preserved by the polyfill design; MEAI does the same reflection internally.")]
+    private static readonly FieldInfo? s_meaiResponseClientField =
+        s_meaiResponsesChatClientType?.GetField("_responseClient", BindingFlags.NonPublic | BindingFlags.Instance);
 }

dotnet/src/Microsoft.Agents.AI.Foundry/RequestOptionsExtensions.cs

@@ -3,7 +3,6 @@
 using System.ClientModel.Primitives;
 using System.Collections.Generic;
 using System.Reflection;
-using System.Threading;
 using System.Threading.Tasks;
 
 namespace Microsoft.Agents.AI;
@@ -13,20 +12,6 @@ internal static class RequestOptionsExtensions
     /// <summary>Gets the singleton <see cref="PipelinePolicy"/> that adds a MEAI user-agent header.</summary>
     internal static PipelinePolicy UserAgentPolicy => MeaiUserAgentPolicy.Instance;
 
-    /// <summary>Creates a <see cref="RequestOptions"/> configured for use with Foundry Agents.</summary>
-    public static RequestOptions ToRequestOptions(this CancellationToken cancellationToken, bool streaming)
-    {
-        RequestOptions requestOptions = new()
-        {
-            CancellationToken = cancellationToken,
-            BufferResponse = !streaming
-        };
-
-        requestOptions.AddPolicy(MeaiUserAgentPolicy.Instance, PipelinePosition.PerCall);
-
-        return requestOptions;
-    }
-
     /// <summary>Provides a pipeline policy that adds a "MEAI/x.y.z" user-agent header.</summary>
     private sealed class MeaiUserAgentPolicy : PipelinePolicy
     {

dotnet/tests/Microsoft.Agents.AI.Foundry.UnitTests/Hosting/DelegatingResponsesClientTests.cs

@@ -0,0 +1,453 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System;
+using System.ClientModel;
+using System.ClientModel.Primitives;
+using System.Collections.Generic;
+using System.Net;
+using System.Net.Http;
+using System.Reflection;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+using Azure.AI.Extensions.OpenAI;
+using Microsoft.Agents.AI.Foundry.Hosting;
+using Microsoft.Extensions.AI;
+using OpenAI;
+using OpenAI.Responses;
+
+#pragma warning disable OPENAI001, SCME0001, SCME0002, MEAI001
+
+namespace Microsoft.Agents.AI.Foundry.UnitTests.Hosting;
+
+/// <summary>
+/// Verifies that <see cref="DelegatingResponsesClient"/> preserves user-supplied client options
+/// (Transport, RetryPolicy, UserAgentApplicationId, OrganizationId, ProjectId) and adds the
+/// hosted-agent User-Agent supplement on every outgoing request, including streaming.
+/// Covers both the Azure-flavored <see cref="ProjectResponsesClient"/> and the native OpenAI
+/// <see cref="ResponsesClient"/>.
+/// </summary>
+public sealed partial class DelegatingResponsesClientTests
+{
+    private const string TestEndpoint = "https://fake-foundry.example.com/api/projects/fake-prj";
+    private const string OpenAIEndpoint = "https://fake-openai.example.com/v1";
+    private const string Deployment = "fake-deployment";
+
+    [System.Text.RegularExpressions.GeneratedRegex("foundry-hosting/agent-framework-dotnet")]
+    private static partial System.Text.RegularExpressions.Regex SupplementRegex();
+
+    [Fact]
+    public async Task Polyfill_NonStreaming_PreservesAppId_ThroughCustomTransport_AddsSupplementAsync()
+    {
+        // Arrange
+        using var handler = new RecordingHandler(MinimalResponseJson());
+#pragma warning disable CA5399
+        using var httpClient = new HttpClient(handler);
+#pragma warning restore CA5399
+        var inner = BuildInner(httpClient, userAgentApplicationId: "MY_APP_ID");
+        var chat = MakeWithDelegating(inner);
+
+        // Act
+        _ = await chat.GetResponseAsync("hello");
+
+        // Assert
+        var req = Assert.Single(handler.Requests);
+        Assert.Contains("MY_APP_ID", req.UserAgent);
+        Assert.Contains("MEAI/", req.UserAgent);
+        Assert.Contains("foundry-hosting/agent-framework-dotnet", req.UserAgent);
+        Assert.StartsWith(TestEndpoint, req.Uri);
+    }
+
+    [Fact]
+    public async Task Polyfill_Streaming_PreservesAppId_ThroughCustomTransport_AddsSupplementAsync()
+    {
+        // Arrange
+        using var handler = new RecordingHandler(MinimalSseResponse());
+#pragma warning disable CA5399
+        using var httpClient = new HttpClient(handler);
+#pragma warning restore CA5399
+        var inner = BuildInner(httpClient, userAgentApplicationId: "MY_APP_ID");
+        var chat = MakeWithDelegating(inner);
+
+        // Act
+        await foreach (var _ in chat.GetStreamingResponseAsync("hello"))
+        {
+        }
+
+        // Assert
+        var req = Assert.Single(handler.Requests);
+        Assert.Contains("MY_APP_ID", req.UserAgent);
+        Assert.Contains("MEAI/", req.UserAgent);
+        Assert.Contains("foundry-hosting/agent-framework-dotnet", req.UserAgent);
+        Assert.StartsWith(TestEndpoint, req.Uri);
+    }
+
+    [Fact]
+    public async Task Polyfill_PreservesOrganizationAndProjectHeadersAsync()
+    {
+        // Arrange
+        using var handler = new RecordingHandler(MinimalResponseJson());
+#pragma warning disable CA5399
+        using var httpClient = new HttpClient(handler);
+#pragma warning restore CA5399
+        var inner = BuildInner(httpClient,
+            userAgentApplicationId: "MY_APP_ID",
+            organizationId: "org_xyz",
+            projectId: "proj_abc");
+        var chat = MakeWithDelegating(inner);
+
+        // Act
+        _ = await chat.GetResponseAsync("hello");
+
+        // Assert
+        var req = Assert.Single(handler.Requests);
+        Assert.Contains("MY_APP_ID", req.UserAgent);
+        Assert.Contains("foundry-hosting/agent-framework-dotnet", req.UserAgent);
+    }
+
+    [Fact]
+    public async Task Polyfill_HonorsUserSuppliedRetryPolicy_ByCountingRetriesAsync()
+    {
+        // Arrange
+        var retryPolicy = new CountingRetryPolicy(extraAttempts: 2);
+        using var handler = new RecordingHandler(MinimalResponseJson());
+#pragma warning disable CA5399
+        using var httpClient = new HttpClient(handler);
+#pragma warning restore CA5399
+        var inner = BuildInner(httpClient, userAgentApplicationId: "MY_APP_ID", retryPolicy: retryPolicy);
+        var chat = MakeWithDelegating(inner);
+
+        // Act
+        _ = await chat.GetResponseAsync("hello");
+
+        // Assert: retry policy ran (1 + 2 extras = 3 attempts).
+        Assert.Equal(3, handler.Requests.Count);
+        Assert.Equal(3, retryPolicy.InvocationCount);
+        foreach (var req in handler.Requests)
+        {
+            Assert.Contains("MY_APP_ID", req.UserAgent);
+            Assert.Contains("MEAI/", req.UserAgent);
+            Assert.Contains("foundry-hosting/agent-framework-dotnet", req.UserAgent);
+        }
+    }
+
+    [Fact]
+    public async Task Baseline_NonStreaming_DoesNotInjectSupplementAsync()
+    {
+        // Arrange
+        using var handler = new RecordingHandler(MinimalResponseJson());
+#pragma warning disable CA5399
+        using var httpClient = new HttpClient(handler);
+#pragma warning restore CA5399
+        var inner = BuildInner(httpClient, userAgentApplicationId: "MY_APP_ID");
+        var chat = inner.AsIChatClient(Deployment);
+
+        // Act
+        _ = await chat.GetResponseAsync("hello");
+
+        // Assert
+        var req = Assert.Single(handler.Requests);
+        Assert.Contains("MY_APP_ID", req.UserAgent);
+        Assert.Contains("MEAI/", req.UserAgent);
+        Assert.DoesNotContain("foundry-hosting/agent-framework-dotnet", req.UserAgent);
+    }
+
+    [Fact]
+    public async Task Polyfill_NativeOpenAIResponsesClient_NonStreaming_AddsSupplementAsync()
+    {
+        // Arrange: use the NATIVE OpenAI SDK ResponsesClient (no Foundry / Azure project involved).
+        using var handler = new RecordingHandler(MinimalResponseJson());
+#pragma warning disable CA5399
+        using var httpClient = new HttpClient(handler);
+#pragma warning restore CA5399
+        var inner = BuildOpenAIInner(httpClient, userAgentApplicationId: "MY_APP_ID");
+        var chat = MakeWithDelegating(inner);
+
+        // Act
+        _ = await chat.GetResponseAsync("hello");
+
+        // Assert
+        var req = Assert.Single(handler.Requests);
+        Assert.Contains("MY_APP_ID", req.UserAgent);
+        Assert.Contains("MEAI/", req.UserAgent);
+        Assert.Contains("foundry-hosting/agent-framework-dotnet", req.UserAgent);
+        Assert.StartsWith(OpenAIEndpoint, req.Uri);
+    }
+
+    [Fact]
+    public async Task Polyfill_NativeOpenAIResponsesClient_Streaming_AddsSupplementAsync()
+    {
+        // Arrange
+        using var handler = new RecordingHandler(MinimalSseResponse());
+#pragma warning disable CA5399
+        using var httpClient = new HttpClient(handler);
+#pragma warning restore CA5399
+        var inner = BuildOpenAIInner(httpClient, userAgentApplicationId: "MY_APP_ID");
+        var chat = MakeWithDelegating(inner);
+
+        // Act
+        await foreach (var _ in chat.GetStreamingResponseAsync("hello"))
+        {
+        }
+
+        // Assert
+        var req = Assert.Single(handler.Requests);
+        Assert.Contains("MY_APP_ID", req.UserAgent);
+        Assert.Contains("MEAI/", req.UserAgent);
+        Assert.Contains("foundry-hosting/agent-framework-dotnet", req.UserAgent);
+        Assert.StartsWith(OpenAIEndpoint, req.Uri);
+    }
+
+    [Theory]
+    [InlineData("DeleteResponseAsync")]
+    [InlineData("CancelResponseAsync")]
+    [InlineData("GetInputTokenCountAsync")]
+    [InlineData("CompactResponseAsync")]
+    [InlineData("GetResponseInputItemCollectionPageAsync")]
+    public async Task Polyfill_AncillaryProtocolMethod_AddsSupplementAsync(string method)
+    {
+        // Arrange: hit the wrapper DIRECTLY (no MEAI in the chain) to simulate user code that
+        // grabs the underlying ResponsesClient via chat.GetService<ResponsesClient>() and invokes
+        // a non-Create/Get protocol method. This is the regression path: without overriding these,
+        // the wrapper's dummy throwing pipeline would fire.
+        using var handler = new RecordingHandler(MinimalResponseJson());
+#pragma warning disable CA5399
+        using var httpClient = new HttpClient(handler);
+#pragma warning restore CA5399
+        var inner = BuildOpenAIInner(httpClient, userAgentApplicationId: "MY_APP_ID");
+        var wrapper = new DelegatingResponsesClient(inner);
+
+        // Act
+        switch (method)
+        {
+            case "DeleteResponseAsync":
+                _ = await wrapper.DeleteResponseAsync("resp_1", options: null!);
+                break;
+            case "CancelResponseAsync":
+                _ = await wrapper.CancelResponseAsync("resp_1", options: null!);
+                break;
+            case "GetInputTokenCountAsync":
+                _ = await wrapper.GetInputTokenCountAsync("application/json", BinaryContent.Create(BinaryData.FromString("{}")));
+                break;
+            case "CompactResponseAsync":
+                _ = await wrapper.CompactResponseAsync("application/json", BinaryContent.Create(BinaryData.FromString("{}")));
+                break;
+            case "GetResponseInputItemCollectionPageAsync":
+                _ = await wrapper.GetResponseInputItemCollectionPageAsync("resp_1", limit: null, order: "asc", after: "a", before: "b", options: null!);
+                break;
+            default:
+                Assert.Fail($"Unhandled method: {method}");
+                break;
+        }
+
+        // Assert
+        var req = Assert.Single(handler.Requests);
+        Assert.Contains("MY_APP_ID", req.UserAgent);
+        Assert.Contains("foundry-hosting/agent-framework-dotnet", req.UserAgent);
+    }
+
+    [Fact]
+    public async Task Polyfill_RetryWithinCall_DoesNotDuplicateSupplementInUserAgentAsync()
+    {
+        // Arrange: a custom retry policy that re-runs the inner pipeline on the SAME message,
+        // so the per-call HostedAgentUserAgentPolicy fires multiple times against the same headers.
+        // The policy's Contains-guard must prevent the supplement from appearing twice.
+        var retryPolicy = new CountingRetryPolicy(extraAttempts: 2);
+        using var handler = new RecordingHandler(MinimalResponseJson());
+#pragma warning disable CA5399
+        using var httpClient = new HttpClient(handler);
+#pragma warning restore CA5399
+        var inner = BuildInner(httpClient, userAgentApplicationId: "MY_APP_ID", retryPolicy: retryPolicy);
+        var chat = MakeWithDelegating(inner);
+
+        // Act
+        _ = await chat.GetResponseAsync("hello");
+
+        // Assert: each retry attempt must have exactly ONE foundry-hosting segment, never two.
+        Assert.Equal(3, handler.Requests.Count);
+        foreach (var req in handler.Requests)
+        {
+            int matches = SupplementRegex().Matches(req.UserAgent).Count;
+            Assert.True(matches == 1, $"Expected exactly one foundry-hosting segment per retry attempt, got {matches}. UA: {req.UserAgent}");
+        }
+    }
+
+    [Fact]
+    public async Task TryApplyUserAgent_CalledTwiceOnSameAgent_DoesNotDoubleWrapAsync()
+    {
+        // Arrange: build a real ChatClientAgent whose IChatClient resolves to MEAI's
+        // OpenAIResponsesChatClient → ProjectResponsesClient (with a fake transport).
+        using var handler = new RecordingHandler(MinimalResponseJson());
+#pragma warning disable CA5399
+        using var httpClient = new HttpClient(handler);
+#pragma warning restore CA5399
+        var inner = BuildInner(httpClient, userAgentApplicationId: "MY_APP_ID");
+        IChatClient chatClient = inner.AsIChatClient(Deployment);
+        AIAgent agent = new ChatClientAgent(chatClient);
+
+        // Act: apply twice.
+        FoundryHostingExtensions.TryApplyUserAgent(agent);
+        FoundryHostingExtensions.TryApplyUserAgent(agent);
+
+        // Assert: invoking the agent produces exactly ONE outbound request whose UA contains
+        // the supplement EXACTLY ONCE (would be twice if the wrapper were nested).
+        _ = await chatClient.GetResponseAsync("hello");
+        var req = Assert.Single(handler.Requests);
+        int matches = SupplementRegex().Matches(req.UserAgent).Count;
+        Assert.True(matches == 1, $"Expected exactly one foundry-hosting segment, got {matches}. UA: {req.UserAgent}");
+    }
+
+    [Fact]
+    public void OpenAIResponsesChatClient_ResponseClientField_ReflectionGuard()
+    {
+        // Guards the polyfill's reflection target. Failure here means MEAI internals
+        // changed and the polyfill needs updating.
+        var meaiType = typeof(MicrosoftExtensionsAIResponsesExtensions).Assembly
+            .GetType("Microsoft.Extensions.AI.OpenAIResponsesChatClient");
+        Assert.NotNull(meaiType);
+
+        var field = meaiType!.GetField("_responseClient", BindingFlags.NonPublic | BindingFlags.Instance);
+        Assert.NotNull(field);
+        Assert.True(typeof(ResponsesClient).IsAssignableFrom(field!.FieldType),
+            $"Expected _responseClient to be assignable to ResponsesClient but was {field.FieldType}.");
+    }
+
+    [Fact]
+    public void ResponsesClient_PipelineProperty_ReflectionGuard()
+    {
+        // The polyfill design assumes ResponsesClient.Pipeline remains accessible.
+        var pipelineProp = typeof(ResponsesClient).GetProperty("Pipeline", BindingFlags.Public | BindingFlags.Instance);
+        Assert.NotNull(pipelineProp);
+        Assert.Equal(typeof(ClientPipeline), pipelineProp!.PropertyType);
+    }
+
+    private static IChatClient MakeWithDelegating(ResponsesClient inner)
+    {
+        IChatClient meai = inner.AsIChatClient(Deployment);
+        var meaiType = meai.GetType();
+        var field = meaiType.GetField("_responseClient", BindingFlags.NonPublic | BindingFlags.Instance)!;
+        field.SetValue(meai, new DelegatingResponsesClient(inner));
+        return meai;
+    }
+
+    private static ProjectResponsesClient BuildInner(
+        HttpClient httpClient,
+        string? userAgentApplicationId = null,
+        string? organizationId = null,
+        string? projectId = null,
+        PipelinePolicy? retryPolicy = null)
+    {
+        var options = new ProjectResponsesClientOptions
+        {
+            Transport = new HttpClientPipelineTransport(httpClient),
+        };
+        if (userAgentApplicationId is not null)
+        {
+            options.UserAgentApplicationId = userAgentApplicationId;
+        }
+        if (organizationId is not null)
+        {
+            options.OrganizationId = organizationId;
+        }
+        if (projectId is not null)
+        {
+            options.ProjectId = projectId;
+        }
+        if (retryPolicy is not null)
+        {
+            options.RetryPolicy = retryPolicy;
+        }
+
+        return new ProjectResponsesClient(new Uri(TestEndpoint), new FakeAuthenticationTokenProvider(), options);
+    }
+
+    private static ResponsesClient BuildOpenAIInner(
+        HttpClient httpClient,
+        string? userAgentApplicationId = null)
+    {
+        var options = new OpenAIClientOptions
+        {
+            Transport = new HttpClientPipelineTransport(httpClient),
+            Endpoint = new Uri(OpenAIEndpoint),
+        };
+        if (userAgentApplicationId is not null)
+        {
+            options.UserAgentApplicationId = userAgentApplicationId;
+        }
+
+        return new ResponsesClient(new ApiKeyCredential("test-key"), options);
+    }
+
+    private static string MinimalResponseJson() => """
+        {
+          "id":"resp_1","object":"response","created_at":1700000000,"status":"completed",
+          "model":"fake","output":[],"usage":{"input_tokens":1,"output_tokens":1,"total_tokens":2}
+        }
+        """;
+
+    private static string MinimalSseResponse()
+    {
+        var sb = new StringBuilder();
+        sb.Append("event: response.completed\n");
+        sb.Append("data: ").Append("""{"type":"response.completed","response":{"id":"resp_1","object":"response","created_at":1700000000,"status":"completed","model":"fake","output":[],"usage":{"input_tokens":1,"output_tokens":1,"total_tokens":2}}}""").Append("\n\n");
+        sb.Append("data: [DONE]\n\n");
+        return sb.ToString();
+    }
+
+    private sealed class RecordingHandler : HttpClientHandler
+    {
+        private readonly string _body;
+        public List<RecordedRequest> Requests { get; } = [];
+
+        public RecordingHandler(string body)
+        {
+            this._body = body;
+        }
+
+        protected override Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
+        {
+            string ua = request.Headers.TryGetValues("User-Agent", out var values)
+                ? string.Join(",", values)
+                : "(none)";
+            this.Requests.Add(new RecordedRequest(request.Method.Method, request.RequestUri?.ToString() ?? "?", ua));
+
+            var resp = new HttpResponseMessage(HttpStatusCode.OK)
+            {
+                Content = new StringContent(this._body, Encoding.UTF8, "application/json"),
+                RequestMessage = request,
+            };
+            return Task.FromResult(resp);
+        }
+    }
+
+    private readonly record struct RecordedRequest(string Method, string Uri, string UserAgent);
+
+    private sealed class CountingRetryPolicy : PipelinePolicy
+    {
+        private readonly int _extraAttempts;
+        public int InvocationCount { get; private set; }
+
+        public CountingRetryPolicy(int extraAttempts)
+        {
+            this._extraAttempts = extraAttempts;
+        }
+
+        public override void Process(PipelineMessage message, IReadOnlyList<PipelinePolicy> pipeline, int currentIndex)
+        {
+            for (int i = 0; i <= this._extraAttempts; i++)
+            {
+                this.InvocationCount++;
+                ProcessNext(message, pipeline, currentIndex);
+            }
+        }
+
+        public override async ValueTask ProcessAsync(PipelineMessage message, IReadOnlyList<PipelinePolicy> pipeline, int currentIndex)
+        {
+            for (int i = 0; i <= this._extraAttempts; i++)
+            {
+                this.InvocationCount++;
+                await ProcessNextAsync(message, pipeline, currentIndex).ConfigureAwait(false);
+            }
+        }
+    }
+}

dotnet/tests/Microsoft.Agents.AI.Foundry.UnitTests/Hosting/HostedOutboundUserAgentTests.cs

@@ -0,0 +1,165 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System;
+using System.ClientModel.Primitives;
+using System.Collections.Generic;
+using System.Net;
+using System.Net.Http;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+using Azure.AI.Extensions.OpenAI;
+using Microsoft.Agents.AI.Foundry.Hosting;
+using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Hosting.Server;
+using Microsoft.AspNetCore.TestHost;
+using Microsoft.Extensions.AI;
+using Microsoft.Extensions.DependencyInjection;
+
+#pragma warning disable OPENAI001, SCME0001, SCME0002, MEAI001
+
+namespace Microsoft.Agents.AI.Foundry.UnitTests.Hosting;
+
+/// <summary>
+/// End-to-end tests that exercise the FULL hosted ASP.NET Core pipeline:
+/// inbound HTTP → MapFoundryResponses → AgentFrameworkResponseHandler → TryApplyUserAgent →
+/// agent invocation → outbound HTTP from inside the hosted environment.
+/// Verifies that the hosted-agent <c>User-Agent</c> supplement reaches the outbound wire,
+/// not just the inbound request.
+/// </summary>
+public sealed class HostedOutboundUserAgentTests : IAsyncDisposable
+{
+    private const string TestEndpoint = "https://fake-foundry.example.com/api/projects/fake-prj";
+    private const string Deployment = "fake-deployment";
+
+    private WebApplication? _app;
+    private HttpClient? _inboundClient;
+    private RecordingHandler? _outboundHandler;
+
+    public async ValueTask DisposeAsync()
+    {
+        this._inboundClient?.Dispose();
+        this._outboundHandler?.Dispose();
+        if (this._app is not null)
+        {
+            await this._app.DisposeAsync();
+        }
+    }
+
+    [Fact]
+    public async Task Hosted_InboundResponsesRequest_TriggersOutboundCall_WithFoundryHostingSupplementAsync()
+    {
+        // Arrange: spin up a real ASP.NET Core TestServer that hosts an AIAgent backed by MEAI's
+        // OpenAIResponsesChatClient → ProjectResponsesClient → fake HTTP transport. This is the
+        // exact production stack minus the network: the only thing not real is the wire transport.
+        await this.StartHostedServerAsync();
+
+        // Act: send an inbound /openai/v1/responses request as the Foundry runtime would.
+        using var inboundRequest = new HttpRequestMessage(HttpMethod.Post, "/responses")
+        {
+            Content = new StringContent(InboundResponsesRequestJson(), Encoding.UTF8, "application/json"),
+        };
+        using var inboundResponse = await this._inboundClient!.SendAsync(inboundRequest);
+        var inboundBody = await inboundResponse.Content.ReadAsStringAsync();
+
+        // Assert: at least one OUTBOUND request reached the fake transport, AND it carries the
+        // foundry-hosting/agent-framework-dotnet/{version} supplement on its User-Agent.
+        // (We don't care about the inbound response shape — only that the agent's call to MEAI
+        // triggered an outbound request whose UA reaches the sandbox boundary correctly.)
+        Assert.True(this._outboundHandler!.Requests.Count > 0,
+            $"Expected at least one outbound request. Inbound status: {(int)inboundResponse.StatusCode}, body: {inboundBody}");
+        var outbound = this._outboundHandler.Requests[0];
+        Assert.StartsWith(TestEndpoint, outbound.Uri);
+        Assert.Contains("MEAI/", outbound.UserAgent);
+        Assert.Contains("foundry-hosting/agent-framework-dotnet", outbound.UserAgent);
+    }
+
+    private async Task StartHostedServerAsync()
+    {
+        var builder = WebApplication.CreateBuilder();
+        builder.WebHost.UseTestServer();
+
+        // Build a real ChatClientAgent whose IChatClient is MEAI's OpenAIResponsesChatClient
+        // wrapping a ProjectResponsesClient backed by a fake HTTP handler. After AgentFrameworkResponseHandler
+        // resolves this agent, TryApplyUserAgent will swap the inner _responseClient with our wrapper.
+        this._outboundHandler = new RecordingHandler(MinimalResponseJson());
+#pragma warning disable CA5399
+        var outboundHttpClient = new HttpClient(this._outboundHandler);
+#pragma warning restore CA5399
+
+        var projectOptions = new ProjectResponsesClientOptions
+        {
+            Transport = new HttpClientPipelineTransport(outboundHttpClient),
+        };
+        var projectResponsesClient = new ProjectResponsesClient(
+            new Uri(TestEndpoint),
+            new FakeAuthenticationTokenProvider(),
+            projectOptions);
+
+        IChatClient chatClient = projectResponsesClient.AsIChatClient(Deployment);
+        AIAgent agent = new ChatClientAgent(chatClient);
+
+        builder.Services.AddFoundryResponses(agent);
+        builder.Services.AddLogging();
+
+        this._app = builder.Build();
+        this._app.MapFoundryResponses();
+
+        await this._app.StartAsync();
+
+        var testServer = this._app.Services.GetRequiredService<IServer>() as TestServer
+            ?? throw new InvalidOperationException("TestServer not found");
+
+        this._inboundClient = testServer.CreateClient();
+    }
+
+    private static string InboundResponsesRequestJson() => """
+        {
+          "model": "fake-deployment",
+          "input": [
+            {
+              "type": "message",
+              "id": "msg_1",
+              "status": "completed",
+              "role": "user",
+              "content": [{ "type": "input_text", "text": "Hello" }]
+            }
+          ]
+        }
+        """;
+
+    private static string MinimalResponseJson() => """
+        {
+          "id":"resp_1","object":"response","created_at":1700000000,"status":"completed",
+          "model":"fake","output":[],"usage":{"input_tokens":1,"output_tokens":1,"total_tokens":2}
+        }
+        """;
+
+    private sealed class RecordingHandler : HttpClientHandler
+    {
+        private readonly string _body;
+        public List<RecordedRequest> Requests { get; } = [];
+
+        public RecordingHandler(string body)
+        {
+            this._body = body;
+        }
+
+        protected override Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
+        {
+            string ua = request.Headers.TryGetValues("User-Agent", out var values)
+                ? string.Join(",", values)
+                : "(none)";
+            this.Requests.Add(new RecordedRequest(request.RequestUri?.ToString() ?? "?", ua));
+
+            var resp = new HttpResponseMessage(HttpStatusCode.OK)
+            {
+                Content = new StringContent(this._body, Encoding.UTF8, "application/json"),
+                RequestMessage = request,
+            };
+            return Task.FromResult(resp);
+        }
+    }
+
+    private readonly record struct RecordedRequest(string Uri, string UserAgent);
+}

dotnet/tests/Microsoft.Agents.AI.Foundry.UnitTests/Hosting/ServiceCollectionExtensionsTests.cs

@@ -4,8 +4,10 @@ using System;
 using System.Linq;
 using Azure.AI.AgentServer.Responses;
 using Microsoft.Agents.AI.Foundry.Hosting;
+using Microsoft.Extensions.AI;
 using Microsoft.Extensions.DependencyInjection;
 using Moq;
+using OpenAI.Responses;
 
 namespace Microsoft.Agents.AI.Foundry.UnitTests.Hosting;
 
@@ -93,4 +95,45 @@ public class ServiceCollectionExtensionsTests
 
         Assert.Same(instrumented, result);
     }
+
+    [Fact]
+    public void TryApplyUserAgent_AgentWithoutChatClient_NoOp()
+    {
+        // Arrange: agent.GetService<IChatClient>() returns null.
+        var mockAgent = new Mock<AIAgent>();
+
+        // Act
+        var result = FoundryHostingExtensions.TryApplyUserAgent(mockAgent.Object);
+
+        // Assert
+        Assert.Same(mockAgent.Object, result);
+    }
+
+    [Fact]
+    public void TryApplyUserAgent_AgentWithNonMeaiChatClient_NoOp()
+    {
+        // Arrange: chat client that does not return MEAI's OpenAIResponsesChatClient via GetService.
+        var mockChatClient = new Mock<IChatClient>();
+        mockChatClient.Setup(c => c.GetService(It.IsAny<Type>(), It.IsAny<object?>())).Returns(null!);
+
+        var mockAgent = new Mock<AIAgent>();
+        mockAgent.Setup(a => a.GetService(typeof(IChatClient), It.IsAny<object?>())).Returns(mockChatClient.Object);
+
+        // Act
+        var result = FoundryHostingExtensions.TryApplyUserAgent(mockAgent.Object);
+
+        // Assert
+        Assert.Same(mockAgent.Object, result);
+    }
+
+    [Fact]
+    public void MeaiOpenAIResponsesChatClient_TypeFullName_ReflectionGuard()
+    {
+        // Guards the polyfill's reflection target type-name.
+        var meaiType = typeof(MicrosoftExtensionsAIResponsesExtensions).Assembly
+            .GetType("Microsoft.Extensions.AI.OpenAIResponsesChatClient");
+        Assert.NotNull(meaiType);
+        Assert.True(typeof(IChatClient).IsAssignableFrom(meaiType!),
+            $"Expected MEAI {meaiType!.FullName} to implement IChatClient.");
+    }
 }

dotnet/tests/Microsoft.Agents.AI.Foundry.UnitTests/Hosting/UserAgentMiddlewareTests.cs

@@ -1,134 +0,0 @@
-// Copyright (c) Microsoft. All rights reserved.
-
-using System;
-using System.Net.Http;
-using System.Text.RegularExpressions;
-using System.Threading.Tasks;
-using Microsoft.Agents.AI.Foundry.Hosting;
-using Microsoft.AspNetCore.Builder;
-using Microsoft.AspNetCore.Hosting.Server;
-using Microsoft.AspNetCore.Http;
-using Microsoft.AspNetCore.TestHost;
-using Microsoft.Extensions.DependencyInjection;
-using Moq;
-
-namespace Microsoft.Agents.AI.Foundry.UnitTests.Hosting;
-
-/// <summary>
-/// Tests for the <c>AgentFrameworkUserAgentMiddleware</c> registered by
-/// <see cref="FoundryHostingExtensions.MapFoundryResponses"/>.
-/// </summary>
-public sealed partial class UserAgentMiddlewareTests : IAsyncDisposable
-{
-    private const string VersionedUserAgentPattern = @"agent-framework-dotnet/\d+\.\d+\.\d+(-[\w.]+)?";
-
-    private WebApplication? _app;
-    private HttpClient? _httpClient;
-
-    public async ValueTask DisposeAsync()
-    {
-        this._httpClient?.Dispose();
-        if (this._app != null)
-        {
-            await this._app.DisposeAsync();
-        }
-    }
-
-    [Fact]
-    public async Task MapFoundryResponses_NoUserAgentHeader_SetsAgentFrameworkUserAgentAsync()
-    {
-        // Arrange
-        await this.CreateTestServerAsync();
-
-        using var request = new HttpRequestMessage(HttpMethod.Get, "/test-ua");
-
-        // Act
-        var response = await this._httpClient!.SendAsync(request);
-        var userAgent = await response.Content.ReadAsStringAsync();
-
-        // Assert
-        Assert.Matches(VersionedUserAgentPattern, userAgent);
-    }
-
-    [Fact]
-    public async Task MapFoundryResponses_WithExistingUserAgent_AppendsAgentFrameworkUserAgentAsync()
-    {
-        // Arrange
-        await this.CreateTestServerAsync();
-
-        using var request = new HttpRequestMessage(HttpMethod.Get, "/test-ua");
-        request.Headers.TryAddWithoutValidation("User-Agent", "MyApp/1.0");
-
-        // Act
-        var response = await this._httpClient!.SendAsync(request);
-        var userAgent = await response.Content.ReadAsStringAsync();
-
-        // Assert
-        Assert.StartsWith("MyApp/1.0", userAgent);
-        Assert.Matches(VersionedUserAgentPattern, userAgent);
-    }
-
-    [Fact]
-    public async Task MapFoundryResponses_AlreadyContainsUserAgent_DoesNotDuplicateAsync()
-    {
-        // Arrange
-        await this.CreateTestServerAsync();
-
-        // First request to capture the actual middleware-generated value
-        using var firstRequest = new HttpRequestMessage(HttpMethod.Get, "/test-ua");
-        var firstResponse = await this._httpClient!.SendAsync(firstRequest);
-        var middlewareValue = await firstResponse.Content.ReadAsStringAsync();
-
-        // Act: send a second request that already contains the middleware value
-        using var secondRequest = new HttpRequestMessage(HttpMethod.Get, "/test-ua");
-        secondRequest.Headers.TryAddWithoutValidation("User-Agent", $"MyApp/2.0 {middlewareValue}");
-        var secondResponse = await this._httpClient!.SendAsync(secondRequest);
-        var userAgent = await secondResponse.Content.ReadAsStringAsync();
-
-        // Assert: should remain unchanged (no duplication)
-        Assert.Equal($"MyApp/2.0 {middlewareValue}", userAgent);
-        Assert.Single(VersionedUserAgentRegex().Matches(userAgent));
-    }
-
-    [Fact]
-    public async Task MapFoundryResponses_UserAgentValue_ContainsVersionAsync()
-    {
-        // Arrange
-        await this.CreateTestServerAsync();
-
-        using var request = new HttpRequestMessage(HttpMethod.Get, "/test-ua");
-
-        // Act
-        var response = await this._httpClient!.SendAsync(request);
-        var userAgent = await response.Content.ReadAsStringAsync();
-
-        // Assert: should match "agent-framework-dotnet/x.y.z" pattern
-        Assert.Matches(VersionedUserAgentPattern, userAgent);
-    }
-
-    private async Task CreateTestServerAsync()
-    {
-        var builder = WebApplication.CreateBuilder();
-        builder.WebHost.UseTestServer();
-
-        var mockAgent = new Mock<AIAgent>();
-        builder.Services.AddFoundryResponses(mockAgent.Object);
-
-        this._app = builder.Build();
-        this._app.MapFoundryResponses();
-
-        // Test endpoint that echoes the User-Agent header after middleware processing
-        this._app.MapGet("/test-ua", (HttpContext ctx) =>
-            Results.Text(ctx.Request.Headers.UserAgent.ToString()));
-
-        await this._app.StartAsync();
-
-        var testServer = this._app.Services.GetRequiredService<IServer>() as TestServer
-            ?? throw new InvalidOperationException("TestServer not found");
-
-        this._httpClient = testServer.CreateClient();
-    }
-
-    [GeneratedRegex(VersionedUserAgentPattern)]
-    private static partial Regex VersionedUserAgentRegex();
-}

dotnet/tests/Microsoft.Agents.AI.Foundry.UnitTests/RequestOptionsExtensionsTests.cs

@@ -0,0 +1,115 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System.ClientModel.Primitives;
+using System.Net;
+using System.Net.Http;
+using System.Reflection;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Microsoft.Agents.AI.Foundry.UnitTests;
+
+/// <summary>
+/// Verifies the per-call <c>MeaiUserAgentPolicy</c> exposed via
+/// <see cref="RequestOptionsExtensions.UserAgentPolicy"/>. The policy is reachable through the
+/// public <see cref="FoundryAgent"/> constructors (which add it to the internally-built
+/// <see cref="Azure.AI.Projects.AIProjectClient"/>'s pipeline), so its behavior is part of the
+/// public API surface.
+/// </summary>
+public sealed class RequestOptionsExtensionsTests
+{
+    [Fact]
+    public async Task MeaiUserAgentPolicy_AddsMeaiSegment_ToOutgoingRequestAsync()
+    {
+        // Arrange
+        using var handler = new RecordingHandler();
+#pragma warning disable CA5399
+        using var httpClient = new HttpClient(handler);
+#pragma warning restore CA5399
+        var pipeline = ClientPipeline.Create(
+            new ClientPipelineOptions { Transport = new HttpClientPipelineTransport(httpClient) },
+            perCallPolicies: [RequestOptionsExtensions.UserAgentPolicy],
+            perTryPolicies: default,
+            beforeTransportPolicies: default);
+
+        // Act
+        var message = pipeline.CreateMessage();
+        message.Request.Method = "POST";
+        message.Request.Uri = new System.Uri("https://example.test/anything");
+        await pipeline.SendAsync(message);
+
+        // Assert
+        Assert.Equal(1, handler.Count);
+        Assert.NotNull(handler.LastUserAgent);
+        Assert.Contains("MEAI/", handler.LastUserAgent);
+    }
+
+    [Fact]
+    public async Task MeaiUserAgentPolicy_DoesNotAddFoundryHostingSegmentAsync()
+    {
+        // Arrange
+        using var handler = new RecordingHandler();
+#pragma warning disable CA5399
+        using var httpClient = new HttpClient(handler);
+#pragma warning restore CA5399
+        var pipeline = ClientPipeline.Create(
+            new ClientPipelineOptions { Transport = new HttpClientPipelineTransport(httpClient) },
+            perCallPolicies: [RequestOptionsExtensions.UserAgentPolicy],
+            perTryPolicies: default,
+            beforeTransportPolicies: default);
+
+        // Act
+        var message = pipeline.CreateMessage();
+        message.Request.Method = "POST";
+        message.Request.Uri = new System.Uri("https://example.test/anything");
+        await pipeline.SendAsync(message);
+
+        // Assert: the policy is MEAI-only; the foundry-hosting supplement is added elsewhere
+        // (by the polyfill DelegatingResponsesClient → HostedAgentUserAgentPolicy).
+        Assert.NotNull(handler.LastUserAgent);
+        Assert.DoesNotContain("foundry-hosting/agent-framework-dotnet", handler.LastUserAgent);
+    }
+
+    [Fact]
+    public void UserAgentPolicy_ExposesSingletonInstance()
+    {
+        // Two reads of the static property must return the same instance — the policy is stateless and shared.
+        var first = RequestOptionsExtensions.UserAgentPolicy;
+        var second = RequestOptionsExtensions.UserAgentPolicy;
+        Assert.Same(first, second);
+    }
+
+    [Fact]
+    public void MeaiUserAgentPolicy_ValueIncludesAFFoundryAssemblyVersion_ReflectionGuard()
+    {
+        // The policy emits "MEAI/{Microsoft.Agents.AI.Foundry assembly InformationalVersion}".
+        // If the assembly metadata stops being readable, the policy falls back to "MEAI" without a version,
+        // which is a measurable telemetry regression.
+        var attr = typeof(RequestOptionsExtensions).Assembly
+            .GetCustomAttribute<AssemblyInformationalVersionAttribute>();
+        Assert.NotNull(attr);
+        Assert.False(string.IsNullOrEmpty(attr!.InformationalVersion));
+    }
+
+    private sealed class RecordingHandler : HttpClientHandler
+    {
+        public int Count { get; private set; }
+        public string? LastUserAgent { get; private set; }
+
+        protected override Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
+        {
+            this.Count++;
+            this.LastUserAgent = request.Headers.TryGetValues("User-Agent", out var values)
+                ? string.Join(",", values)
+                : null;
+
+            var resp = new HttpResponseMessage(HttpStatusCode.OK)
+            {
+                Content = new StringContent("{}", Encoding.UTF8, "application/json"),
+                RequestMessage = request,
+            };
+            return Task.FromResult(resp);
+        }
+    }
+}

python/samples/04-hosting/foundry-hosted-agents/README.md

@@ -13,7 +13,8 @@ This directory contains samples that demonstrate how to use hosted [Agent Framew
 | 3 | [MCP](responses/03_mcp/) | An agent connected to a remote MCP server (GitHub), demonstrating external MCP tool provider integration. |
 | 4 | [Foundry Toolbox](responses/04_foundry_toolbox/) | An agent using Azure Foundry Toolbox, demonstrating toolbox provisioning and querying available tools at runtime. |
 | 5 | [Workflows](responses/05_workflows/) | An agent with a multi-step orchestrated workflow, demonstrating chaining prompts through an orchestrated flow. |
-| 6 | [Using deployed agent](responses/using_deployed_agent.py) | A sample demonstrating how to invoke an agent that has already been deployed to Foundry, showing how to interact with a hosted agent in code. |
+| 6 | [Files](responses/06_files/) | An agent demonstrating how to work with files in a hosted agent session, including uploading files to a hosted agent session and having the agent read and manipulate those files at runtime. |
+| 7 | [Using deployed agent](responses/using_deployed_agent.py) | A sample demonstrating how to invoke an agent that has already been deployed to Foundry, showing how to interact with a hosted agent in code. |
 
 ### Invocations API
 

python/samples/04-hosting/foundry-hosted-agents/responses/01_basic/README.md

@@ -14,6 +14,10 @@ See [main.py](main.py) for the full implementation.
 
 The agent is hosted using the [Agent Framework](https://github.com/microsoft/agent-framework) with the `ResponsesHostServer`, which provisions a REST API endpoint compatible with the OpenAI Responses protocol.
 
+## Running the Agent Host
+
+Follow the instructions in the [Running the Agent Host Locally](../../README.md#running-the-agent-host-locally) section of the README in the parent directory to run the agent host.
+
 ## Interacting with the agent
 
 > Depending on how you run the agent host, you can invoke the agent using `curl` (`Invoke-WebRequest` in PowerShell) or `azd`. Please refer to the [parent README](../../README.md) for more details. Use this README for sample queries you can send to the agent.

python/samples/04-hosting/foundry-hosted-agents/responses/01_basic/agent.yaml

@@ -6,4 +6,7 @@ protocols:
     version: 1.0.0
 resources:
   cpu: '0.25'
-  memory: '0.5Gi'
+  memory: '0.5Gi'
+environment_variables:
+  - name: AZURE_AI_MODEL_DEPLOYMENT_NAME
+    value: ${AZURE_AI_MODEL_DEPLOYMENT_NAME}

python/samples/04-hosting/foundry-hosted-agents/responses/02_tools/agent.yaml

@@ -5,4 +5,7 @@ protocols:
     version: 1.0.0
 resources:
   cpu: "0.25"
-  memory: 0.5Gi
+  memory: 0.5Gi
+environment_variables:
+  - name: AZURE_AI_MODEL_DEPLOYMENT_NAME
+    value: ${AZURE_AI_MODEL_DEPLOYMENT_NAME}

python/samples/04-hosting/foundry-hosted-agents/responses/02_tools/main.py

@@ -25,7 +25,7 @@ def get_weather(
     return f"The weather in {location} is {conditions[randint(0, 3)]} with a high of {randint(10, 30)}°C."
 
 
-@tool(approval_mode="always_require")
+@tool(approval_mode="never_require")
 def run_bash(command: str) -> str:
     """Execute a shell command locally and return stdout, stderr, and exit code."""
     try:

python/samples/04-hosting/foundry-hosted-agents/responses/03_mcp/agent.yaml

@@ -7,5 +7,7 @@ resources:
   cpu: "0.25"
   memory: 0.5Gi
 environment_variables:
+  - name: AZURE_AI_MODEL_DEPLOYMENT_NAME
+    value: ${AZURE_AI_MODEL_DEPLOYMENT_NAME}
   - name: GITHUB_PAT
     value: ${GITHUB_PAT}

python/samples/04-hosting/foundry-hosted-agents/responses/04_foundry_toolbox/README.md

@@ -16,8 +16,6 @@ You can also create a Foundry Toolbox in the Foundry portal. Read more about it
 
 The agent uses `FoundryChatClient` from the Agent Framework to create an OpenAI-compatible Responses client. It loads a named Foundry Toolbox via `client.get_toolbox(name)` — the toolbox is a server-side bundle of tool configurations (e.g., `code_interpreter`, `web_search`) defined in the Foundry portal or by `azd provision`. Omitting `version` resolves the toolbox's current default version at runtime.
 
-The sample then narrows the toolbox to a subset of tool types via `select_toolbox_tools(toolbox, include_types=[...])` before handing it to the agent. This demonstrates how one toolbox can be reused across agents that each expose only the tools they need — here, the agent only sees `code_interpreter` even though the toolbox also includes `web_search`.
-
 See [main.py](main.py) for the full implementation.
 
 ### Agent Hosting
@@ -28,6 +26,18 @@ The agent is hosted using the [Agent Framework](https://github.com/microsoft/age
 
 Follow the instructions in the [Running the Agent Host Locally](../../README.md#running-the-agent-host-locally) section of the README in the parent directory to run the agent host.
 
+An extra environment variable `TOOLBOX_NAME` must be set to the name of the Foundry Toolbox that the agent should load at runtime. This allows the agent host to dynamically retrieve the correct toolbox from Foundry when it starts. Run the following:
+
+```bash
+export TOOLBOX_NAME="<your-toolbox-name>"
+```
+
+Or in PowerShell:
+
+```powershell
+$env:TOOLBOX_NAME="<your-toolbox-name>"
+```
+
 ## Interacting with the agent
 
 > Depending on how you run the agent host, you can invoke the agent using `curl` (`Invoke-WebRequest` in PowerShell) or `azd`. Please refer to the [parent README](../../README.md) for more details. Use this README for sample queries you can send to the agent.

python/samples/04-hosting/foundry-hosted-agents/responses/04_foundry_toolbox/agent.yaml

@@ -5,4 +5,9 @@ protocols:
     version: 1.0.0
 resources:
   cpu: "0.25"
-  memory: 0.5Gi
+  memory: 0.5Gi
+environment_variables:
+  - name: AZURE_AI_MODEL_DEPLOYMENT_NAME
+    value: ${AZURE_AI_MODEL_DEPLOYMENT_NAME}
+  - name: TOOLBOX_NAME
+    value: "agent-tools"

python/samples/04-hosting/foundry-hosted-agents/responses/05_workflows/agent.yaml

@@ -5,4 +5,7 @@ protocols:
     version: 1.0.0
 resources:
   cpu: "0.25"
-  memory: 0.5Gi
+  memory: 0.5Gi
+environment_variables:
+  - name: AZURE_AI_MODEL_DEPLOYMENT_NAME
+    value: ${AZURE_AI_MODEL_DEPLOYMENT_NAME}

python/samples/04-hosting/foundry-hosted-agents/responses/06_files/.dockerignore

@@ -0,0 +1,9 @@
+.venv
+__pycache__
+*.pyc
+*.pyo
+*.pyd
+.Python
+
+# Local-only client tooling and sample data; not needed inside the agent image.
+resources/

python/samples/04-hosting/foundry-hosted-agents/responses/06_files/.env.example

@@ -0,0 +1,3 @@
+FOUNDRY_PROJECT_ENDPOINT="..."
+AZURE_AI_MODEL_DEPLOYMENT_NAME="..."
+TOOLBOX_NAME="..."

python/samples/04-hosting/foundry-hosted-agents/responses/06_files/Dockerfile

@@ -0,0 +1,16 @@
+FROM python:3.12-slim
+
+WORKDIR /app
+
+COPY . user_agent/
+WORKDIR /app/user_agent
+
+RUN if [ -f requirements.txt ]; then \
+        pip install -r requirements.txt; \
+    else \
+        echo "No requirements.txt found"; \
+    fi
+
+EXPOSE 8088
+
+CMD ["python", "main.py"]

python/samples/04-hosting/foundry-hosted-agents/responses/06_files/README.md

@@ -0,0 +1,115 @@
+# What this sample demonstrates
+
+An [Agent Framework](https://github.com/microsoft/agent-framework) agent that uses a local shell tool and a code interpreter tool for working with files, and hosted using the **Responses protocol**.
+
+## How It Works
+
+### Model Integration
+
+The agent uses `FoundryChatClient` from the Agent Framework to create a Responses client from the project endpoint and model deployment. The agent supports both streaming (SSE events) and non-streaming (JSON) response modes.
+
+See [main.py](main.py) for the full implementation.
+
+### Agent Hosting
+
+The agent is hosted using the [Agent Framework](https://github.com/microsoft/agent-framework) with the `ResponsesHostServer`, which provisions a REST API endpoint compatible with the OpenAI Responses protocol.
+
+### Tools
+
+This agent uses four tools:
+
+1. **Get Current Working Directory Tool (`get_cwd`)** – Returns the current working directory of the agent host process.
+2. **List Files Tool (`list_files`)** – Lists the files in a specified directory.
+3. **Read File Tool (`read_file`)** – Reads the contents of a specified file.
+4. **Code Interpreter Tool (`code_interpreter`)** – Allows the agent to execute Python code in a safe.
+
+> In this sample, the filesystem tools are function tools defined in Python using the `@tool` decorator from the Agent Framework. The code interpreter tool is a managed tool provided by [Foundry Toolbox](https://learn.microsoft.com/en-us/azure/foundry/agents/how-to/tools/toolbox). Learn more about foundry toolbox integration with hosted agents with this [sample](../04_foundry_toolbox/).
+
+## Running the Agent Host
+
+Follow the instructions in the [Running the Agent Host Locally](../../README.md#running-the-agent-host-locally) section of the README in the parent directory to run the agent host.
+
+An extra environment variable `TOOLBOX_NAME` must be set to the name of the Foundry Toolbox that the agent should load at runtime. This allows the agent host to dynamically retrieve the correct toolbox from Foundry when it starts. Run the following:
+
+```bash
+export TOOLBOX_NAME="<your-toolbox-name>"
+```
+
+Or in PowerShell:
+
+```powershell
+$env:TOOLBOX_NAME="<your-toolbox-name>"
+```
+
+## Interacting with the agent
+
+> Depending on how you run the agent host, you can invoke the agent using `curl` (`Invoke-WebRequest` in PowerShell) or `azd`. Please refer to the [parent README](../../README.md) for more details. Use this README for sample queries you can send to the agent.
+
+Send a POST request to the server with a JSON body containing an `"input"` field to interact with the agent. For example:
+
+```bash
+curl -X POST http://localhost:8088/responses -H "Content-Type: application/json" -d '{"input": "Find the quarterly report under `{cwd}/resources` and tell me the difference of revenue between q1 2026 and q1 2025?"}'
+```
+
+> When ruuning locally, it runs within the project directory, which contains the entire sample, so the `{cwd}/resources` path in the query above will allow the agent to locate the `resources` folder included with this sample and read the `contoso_q1_2026_report.txt` file from that folder.
+
+The server will respond with a JSON object containing the response text and a response ID. You can use this response ID to continue the conversation in subsequent requests.
+
+## Deploying the Agent to Foundry
+
+To host the agent on Foundry, follow the instructions in the [Deploying the Agent to Foundry](../../README.md#deploying-the-agent-to-foundry) section of the README in the parent directory.
+
+## Uploading a file to a session
+
+Deploying the agent won't automatically upload the files included with this sample to Foundry. To make these files available to the agent at runtime, you must upload them to a [hosted agent session](https://learn.microsoft.com/azure/foundry/agents/how-to/manage-hosted-sessions). Files are tied to a specific hosted agent session, so each time you start a new session you will need to upload the files again if the agent needs access to them during that session.
+
+After you deploy the agent to Foundry, you have two ways to interact with the agent:
+
+1. Using `azd ai agent invoke`.
+2. Through the Foundry portal.
+
+### Using `azd ai agent invoke`
+
+After successfully deploying the agent to Foundry, run the following command:
+
+> You must remain in the directory where your `azd` project is initialized so that the CLI can locate the deployed agent configuration.
+
+```bash
+azd ai agent invoke "Hi!"
+```
+
+The command will invoke the agent and the server will create a new session if one does not already exist for this interaction, returning the agent's response from the hosted agent session. Run the following if you want to force a new session:
+
+```bash
+azd ai agent invoke --new-session "Hi!"
+```
+
+Run the following command to upload a file to the hosted agent session:
+
+```bash
+azd ai agent files upload -f <path-to-contoso_q1_2026_report.txt>
+```
+
+> The above command will automatically detect the last active session and upload the file to that session without requiring you to explicitly provide a session ID. It is also possible to specify a particular session ID to upload the file to a specific hosted agent session by using the `--session-id` flag. Run `azd ai agent files upload -h` to see the full list of options and flags available for the `upload` command.
+
+Once the file is uploaded to the hosted agent session, the agent will be able to access it during that session and use it to respond to queries that reference the uploaded file.
+
+Invoke the agent again with a query that references the uploaded file to see how it can now use the file in its responses. For example:
+
+```bash
+azd ai agent invoke "Find the quarterly report under the home directory and tell me the difference of revenue between q1 2026 and q1 2025?"
+```
+
+### Using the Foundry Portal
+
+Similar to using the `azd` CLI, you must invoke the agent first to create a session:
+
+![alt text](./resources/start-a-session.png)
+
+Once the session is created, you can grab the session ID and use `azd ai agent files upload --session-id <session-id>` to upload files to that specific hosted agent session.
+
+![alt text](./resources/session-started.png)
+
+Or you can upload files directly through the Foundry portal by navigating to Files tab in the agent playground:
+
+![alt text](./resources/file-upload-portal.png)

python/samples/04-hosting/foundry-hosted-agents/responses/06_files/agent.manifest.yaml

@@ -0,0 +1,32 @@
+name: agent-framework-agent-files-responses
+description: >
+  An Agent Framework agent that can work with files hosted by Foundry.
+metadata:
+  tags:
+    - Agent Framework
+    - AI Agent Hosting
+    - Azure AI AgentServer
+    - Responses Protocol
+    - Streaming
+template:
+  name: agent-framework-agent-files-responses
+  kind: hosted
+  protocols:
+    - protocol: responses
+      version: 1.0.0
+  environment_variables:
+    - name: AZURE_AI_MODEL_DEPLOYMENT_NAME
+      value: "{{AZURE_AI_MODEL_DEPLOYMENT_NAME}}"
+    - name: TOOLBOX_NAME
+      value: "agent-tools"
+resources:
+  - kind: model
+    id: gpt-4.1-mini
+    name: AZURE_AI_MODEL_DEPLOYMENT_NAME
+  - kind: toolbox
+    name: agent-tools
+    tools:
+      - type: web_search
+        name: web_search
+      - type: code_interpreter
+        name: code_interpreter

python/samples/04-hosting/foundry-hosted-agents/responses/06_files/agent.yaml

@@ -0,0 +1,12 @@
+# yaml-language-server: $schema=https://raw.githubusercontent.com/microsoft/AgentSchema/refs/heads/main/schemas/v1.0/ContainerAgent.yaml
+kind: hosted
+name: agent-framework-agent-files-responses
+protocols:
+  - protocol: responses
+    version: 1.0.0
+resources:
+  cpu: '0.25'
+  memory: '0.5Gi'
+environment_variables:
+  - name: AZURE_AI_MODEL_DEPLOYMENT_NAME
+    value: ${AZURE_AI_MODEL_DEPLOYMENT_NAME}

python/samples/04-hosting/foundry-hosted-agents/responses/06_files/main.py

@@ -0,0 +1,83 @@
+# Copyright (c) Microsoft. All rights reserved.
+
+import asyncio
+import os
+
+from agent_framework import Agent, tool
+from agent_framework.foundry import FoundryChatClient
+from agent_framework_foundry import select_toolbox_tools
+from agent_framework_foundry_hosting import ResponsesHostServer
+from azure.identity import DefaultAzureCredential
+from dotenv import load_dotenv
+
+# Load environment variables from .env file
+load_dotenv()
+
+
+@tool(description="Get the current working directory.", approval_mode="never_require")
+def get_cwd() -> str:
+    """Get the current working directory."""
+    try:
+        return os.getcwd()
+    except Exception as e:
+        return f"Error getting current working directory: {e}"
+
+
+@tool(description="List files in a directory.", approval_mode="never_require")
+def list_files(directory: str) -> list[str]:
+    """List files in a directory."""
+    try:
+        return os.listdir(directory)
+    except Exception as e:
+        return [f"Error listing files in {directory}: {e}"]
+
+
+@tool(description="Read the contents of a file.", approval_mode="never_require")
+def read_file(file_path: str) -> str:
+    """Read the contents of a file."""
+    try:
+        with open(file_path) as f:
+            return f.read()
+    except Exception as e:
+        return f"Error reading file {file_path}: {e}"
+
+
+async def main():
+    client = FoundryChatClient(
+        project_endpoint=os.environ["FOUNDRY_PROJECT_ENDPOINT"],
+        model=os.environ["AZURE_AI_MODEL_DEPLOYMENT_NAME"],
+        credential=DefaultAzureCredential(),
+    )
+
+    # Load the named toolbox from the Foundry project. Omitting `version`
+    # resolves the toolbox's current default version at runtime.
+    toolbox = await client.get_toolbox(os.environ["TOOLBOX_NAME"])
+    # The toolbox deployed has two tools: (see agent.manifest.yaml)
+    # - `code_interpreter`
+    # - `web_search`
+    # We only need the `code_interpreter` tool for this sample
+    selected_tools = select_toolbox_tools(
+        toolbox,
+        include_names=["code_interpreter"],
+    )
+
+    agent = Agent(
+        client=client,
+        instructions=(
+            "You are a friendly assistant. Keep your answers brief. "
+            "Make sure all mathematical calculations are performed using the code interpreter "
+            "instead of mental arithmetic."
+        ),
+        tools=[get_cwd, list_files, read_file] + selected_tools,
+        # History will be managed by the hosting infrastructure, thus there
+        # is no need to store history by the service. Learn more at:
+        # https://developers.openai.com/api/reference/resources/responses/methods/create
+        default_options={"store": False},
+    )
+
+    server = ResponsesHostServer(agent)
+    await server.run_async()
+
+
+if __name__ == "__main__":
+    asyncio.run(main())

python/samples/04-hosting/foundry-hosted-agents/responses/06_files/requirements.txt

@@ -0,0 +1,2 @@
+agent-framework
+agent-framework-foundry-hosting

python/samples/04-hosting/foundry-hosted-agents/responses/06_files/resources/contoso_q1_2026_report.txt

@@ -0,0 +1,121 @@
+Contoso Corporation
+Quarterly Report — Q1 2026 (Three months ended March 31, 2026)
+
+DISCLAIMER
+This document contains fictional data for sample/demo purposes only.
+Contoso is a fictional company; all figures below are fabricated.
+
+------------------------------------------------------------
+1. EXECUTIVE SUMMARY
+------------------------------------------------------------
+Contoso delivered a solid first quarter, with total revenue of
+$1,482.6M, up 11.4% year-over-year. Growth was led by the Cloud
+Services segment (+22.7% YoY) and continued double-digit expansion
+in International markets. Operating margin expanded 140 basis points
+to 23.8% on disciplined cost management and improved gross margin.
+
+Key highlights:
+  - Revenue: $1,482.6M (YoY +11.4%)
+  - Gross profit: $912.0M (gross margin 61.5%)
+  - Operating income: $352.9M (operating margin 23.8%)
+  - Net income: $268.4M (net margin 18.1%)
+  - Diluted EPS: $1.27 (vs. $1.04 prior year)
+  - Free cash flow: $311.5M
+  - Cash & equivalents: $2,140.8M
+
+------------------------------------------------------------
+2. INCOME STATEMENT (USD millions, unaudited)
+------------------------------------------------------------
+                                     Q1 2026     Q1 2025     YoY %
+Revenue                              1,482.6     1,330.7     +11.4%
+Cost of revenue                        570.6       538.9      +5.9%
+Gross profit                           912.0       791.8     +15.2%
+  Gross margin                          61.5%       59.5%    +200 bps
+Operating expenses
+  Research & development               241.4       220.5      +9.5%
+  Sales & marketing                    218.7       205.1      +6.6%
+  General & administrative              99.0        88.6     +11.7%
+Total operating expenses               559.1       514.2      +8.7%
+Operating income                       352.9       277.6     +27.1%
+  Operating margin                      23.8%       20.9%    +290 bps
+Other income / (expense), net            8.4         5.1
+Income before taxes                    361.3       282.7
+Provision for income taxes              92.9        72.6
+Net income                             268.4       210.1     +27.7%
+Diluted EPS (USD)                       1.27        1.04     +22.1%
+
+------------------------------------------------------------
+3. REVENUE BY SEGMENT (USD millions)
+------------------------------------------------------------
+Segment                              Q1 2026     Q1 2025     YoY %
+Cloud Services                         612.4       499.1     +22.7%
+Productivity Software                  448.9       422.6      +6.2%
+Devices & Hardware                     267.0       260.4      +2.5%
+Professional Services                  154.3       148.6      +3.8%
+Total revenue                        1,482.6     1,330.7     +11.4%
+
+------------------------------------------------------------
+4. REVENUE BY GEOGRAPHY (USD millions)
+------------------------------------------------------------
+Region                               Q1 2026     Q1 2025     YoY %
+North America                          812.1       756.0      +7.4%
+EMEA                                   388.5       340.2     +14.2%
+Asia-Pacific                           221.7       183.4     +20.9%
+Latin America                           60.3        51.1     +18.0%
+Total revenue                        1,482.6     1,330.7     +11.4%
+
+------------------------------------------------------------
+5. SELECTED BALANCE SHEET ITEMS (USD millions)
+------------------------------------------------------------
+                                     Mar 31,     Dec 31,
+                                       2026        2025
+Cash & equivalents                   2,140.8     1,902.3
+Short-term investments                 845.6       820.4
+Accounts receivable, net             1,012.7       988.5
+Total current assets                 4,510.2     4,190.6
+Goodwill & intangibles               2,330.1     2,338.9
+Total assets                         9,884.5     9,512.0
+Total current liabilities            2,118.4     2,054.7
+Long-term debt                       1,750.0     1,750.0
+Total liabilities                    4,402.6     4,310.5
+Total stockholders' equity           5,481.9     5,201.5
+
+------------------------------------------------------------
+6. CASH FLOW HIGHLIGHTS (USD millions)
+------------------------------------------------------------
+                                     Q1 2026     Q1 2025
+Net cash from operating activities     382.0       298.7
+Capital expenditures                   (70.5)      (62.1)
+Free cash flow                         311.5       236.6
+Share repurchases                     (120.0)      (90.0)
+Dividends paid                         (54.2)      (48.6)
+
+------------------------------------------------------------
+7. KEY OPERATING METRICS
+------------------------------------------------------------
+Cloud paid seats (millions)             48.6        39.7     +22.4%
+Cloud net revenue retention            118%        114%
+Active enterprise customers          18,420      16,905      +9.0%
+Headcount (end of period)            22,140      20,610      +7.4%
+
+------------------------------------------------------------
+8. OUTLOOK — Q2 2026 GUIDANCE
+------------------------------------------------------------
+Revenue:           $1,520M – $1,560M (YoY +10% to +13%)
+Operating margin:  23.5% – 24.5%
+Diluted EPS:       $1.30 – $1.36
+Capital expenditures: ~$80M
+
+Management remains confident in the full-year plan and reiterates
+fiscal-year 2026 revenue growth of 10–12% and operating-margin
+expansion of 100–150 basis points versus FY 2025.
+
+------------------------------------------------------------
+9. NOTES
+------------------------------------------------------------
+- All figures are unaudited and rounded to one decimal place.
+- Year-over-year comparisons are versus the same period in 2025.
+- "Free cash flow" is defined as net cash from operating activities
+  less capital expenditures, and is a non-GAAP measure.
+- This sample report is intended solely for demonstration of an
+  agent-driven document analysis pipeline.