diff --git a/dotnet/src/Microsoft.Agents.AI.Hosting.A2A/A2AAgentHandler.cs b/dotnet/src/Microsoft.Agents.AI.Hosting.A2A/A2AAgentHandler.cs
index 65bc4c30bd..2113d273e0 100644
--- a/dotnet/src/Microsoft.Agents.AI.Hosting.A2A/A2AAgentHandler.cs
+++ b/dotnet/src/Microsoft.Agents.AI.Hosting.A2A/A2AAgentHandler.cs
@@ -42,11 +42,19 @@ public A2AAgentHandler(
     /// <inheritdoc/>
     public Task ExecuteAsync(RequestContext context, AgentEventQueue eventQueue, CancellationToken cancellationToken)
     {
+        // Handle task updates
         if (context.IsContinuation)
         {
             return this.HandleTaskUpdateAsync(context, eventQueue, cancellationToken);
         }
 
+        // Handle messages received via streaming endpoint
+        if (context.StreamingResponse)
+        {
+            return this.HandleNewMessageStreamingAsync(context, eventQueue, cancellationToken);
+        }
+
+        // Handle new messages received via non-streaming endpoint
         return this.HandleNewMessageAsync(context, eventQueue, cancellationToken);
     }
 
@@ -80,13 +88,19 @@ private async Task HandleNewMessageAsync(RequestContext context, AgentEventQueue
             ? new AgentRunOptions { AllowBackgroundResponses = allowBackgroundResponses }
             : new AgentRunOptions { AllowBackgroundResponses = allowBackgroundResponses, AdditionalProperties = context.Metadata.ToAdditionalProperties() };
 
-        var response = await this._hostAgent.RunAsync(
-            chatMessages,
-            session: session,
-            options: options,
-            cancellationToken: cancellationToken).ConfigureAwait(false);
-
-        await this._hostAgent.SaveSessionAsync(contextId, session, cancellationToken).ConfigureAwait(false);
+        AgentResponse response;
+        try
+        {
+            response = await this._hostAgent.RunAsync(
+                chatMessages,
+                session: session,
+                options: options,
+                cancellationToken: cancellationToken).ConfigureAwait(false);
+        }
+        finally
+        {
+            await this._hostAgent.SaveSessionAsync(contextId, session, CancellationToken.None).ConfigureAwait(false);
+        }
 
         if (response.ContinuationToken is null)
         {
@@ -108,6 +122,39 @@ private async Task HandleNewMessageAsync(RequestContext context, AgentEventQueue
         }
     }
 
+    private async Task HandleNewMessageStreamingAsync(RequestContext context, AgentEventQueue eventQueue, CancellationToken cancellationToken)
+    {
+        var contextId = context.ContextId ?? Guid.NewGuid().ToString("N");
+        var session = await this._hostAgent.GetOrCreateSessionAsync(contextId, cancellationToken).ConfigureAwait(false);
+
+        // AIAgent does not support resuming from arbitrary prior tasks.
+        // Throw explicitly so the client gets a clear error rather than a response
+        // that silently ignores the referenced task context.
+        if (context.Message?.ReferenceTaskIds is { Count: > 0 })
+        {
+            throw new NotSupportedException("ReferenceTaskIds is not supported. AIAgent cannot resume from arbitrary prior task context.");
+        }
+
+        List<ChatMessage> chatMessages = context.Message is not null ? [context.Message.ToChatMessage()] : [];
+
+        var options = context.Metadata is { Count: > 0 }
+            ? new AgentRunOptions { AdditionalProperties = context.Metadata.ToAdditionalProperties() }
+            : null;
+
+        try
+        {
+            await foreach (var update in this._hostAgent.RunStreamingAsync(chatMessages, session, options, cancellationToken).ConfigureAwait(false))
+            {
+                var message = CreateMessageFromUpdate(contextId, update);
+                await eventQueue.EnqueueMessageAsync(message, cancellationToken).ConfigureAwait(false);
+            }
+        }
+        finally
+        {
+            await this._hostAgent.SaveSessionAsync(contextId, session, CancellationToken.None).ConfigureAwait(false);
+        }
+    }
+
     private async Task HandleTaskUpdateAsync(RequestContext context, AgentEventQueue eventQueue, CancellationToken cancellationToken)
     {
         var contextId = context.ContextId ?? Guid.NewGuid().ToString("N");
@@ -141,8 +188,10 @@ private async Task HandleTaskUpdateAsync(RequestContext context, AgentEventQueue
             await failUpdater.FailAsync(message: null, CancellationToken.None).ConfigureAwait(false);
             throw;
         }
-
-        await this._hostAgent.SaveSessionAsync(contextId, session, cancellationToken).ConfigureAwait(false);
+        finally
+        {
+            await this._hostAgent.SaveSessionAsync(contextId, session, CancellationToken.None).ConfigureAwait(false);
+        }
 
         if (response.ContinuationToken is null)
         {
@@ -174,6 +223,16 @@ private static Message CreateMessageFromResponse(string contextId, AgentResponse
             Metadata = response.AdditionalProperties?.ToA2AMetadata()
         };
 
+    private static Message CreateMessageFromUpdate(string contextId, AgentResponseUpdate update) =>
+        new()
+        {
+            MessageId = update.ResponseId ?? Guid.NewGuid().ToString("N"),
+            ContextId = contextId,
+            Role = Role.Agent,
+            Parts = update.ToParts(),
+            Metadata = update.AdditionalProperties?.ToA2AMetadata()
+        };
+
     private static List<ChatMessage> ExtractChatMessagesFromTaskHistory(AgentTask? agentTask)
     {
         if (agentTask?.History is not { Count: > 0 })
diff --git a/dotnet/src/Microsoft.Agents.AI.Hosting.A2A/Converters/MessageConverter.cs b/dotnet/src/Microsoft.Agents.AI.Hosting.A2A/Converters/MessageConverter.cs
index b2f57fc09e..a231f322c4 100644
--- a/dotnet/src/Microsoft.Agents.AI.Hosting.A2A/Converters/MessageConverter.cs
+++ b/dotnet/src/Microsoft.Agents.AI.Hosting.A2A/Converters/MessageConverter.cs
@@ -8,6 +8,26 @@ namespace Microsoft.Agents.AI.Hosting.A2A.Converters;
 
 internal static class MessageConverter
 {
+    public static List<Part> ToParts(this AgentResponseUpdate update)
+    {
+        if (update is null || update.Contents is not { Count: > 0 })
+        {
+            return [];
+        }
+
+        var parts = new List<Part>();
+        foreach (var content in update.Contents)
+        {
+            var part = content.ToPart();
+            if (part is not null)
+            {
+                parts.Add(part);
+            }
+        }
+
+        return parts;
+    }
+
     public static List<Part> ToParts(this IList<ChatMessage> chatMessages)
     {
         if (chatMessages is null || chatMessages.Count == 0)
diff --git a/dotnet/tests/Microsoft.Agents.AI.Hosting.A2A.UnitTests/A2AAgentHandlerTests.cs b/dotnet/tests/Microsoft.Agents.AI.Hosting.A2A.UnitTests/A2AAgentHandlerTests.cs
index 6558144184..b54b3d7db7 100644
--- a/dotnet/tests/Microsoft.Agents.AI.Hosting.A2A.UnitTests/A2AAgentHandlerTests.cs
+++ b/dotnet/tests/Microsoft.Agents.AI.Hosting.A2A.UnitTests/A2AAgentHandlerTests.cs
@@ -586,6 +586,457 @@ await handler.CancelAsync(
 
 #pragma warning restore MEAI001
 
+    /// <summary>
+    /// Verifies that in streaming mode, each update from RunStreamingAsync produces a message event.
+    /// </summary>
+    [Fact]
+    public async Task ExecuteAsync_Streaming_EnqueuesMessageForEachUpdateAsync()
+    {
+        // Arrange
+        AgentResponseUpdate[] updates =
+        [
+            new AgentResponseUpdate(ChatRole.Assistant, "chunk 1") { ResponseId = "r1" },
+            new AgentResponseUpdate(ChatRole.Assistant, "chunk 2") { ResponseId = "r2" }
+        ];
+        A2AAgentHandler handler = CreateHandler(CreateStreamingAgentMock(updates));
+
+        // Act
+        var events = await CollectEventsAsync(handler, new RequestContext
+        {
+            StreamingResponse = true,
+            TaskId = "",
+            ContextId = "ctx",
+            Message = new Message { MessageId = "test-id", Role = Role.User, Parts = [new Part { Text = "Hello" }] }
+        });
+
+        // Assert
+        Assert.Equal(2, events.Messages.Count);
+        Assert.Equal("chunk 1", events.Messages[0].Parts![0].Text);
+        Assert.Equal("chunk 2", events.Messages[1].Parts![0].Text);
+    }
+
+    /// <summary>
+    /// Verifies that in streaming mode, when metadata is present, options with AdditionalProperties
+    /// are passed to RunStreamingAsync.
+    /// </summary>
+    [Fact]
+    public async Task ExecuteAsync_Streaming_WithMetadata_PassesOptionsWithAdditionalPropertiesAsync()
+    {
+        // Arrange
+        AgentRunOptions? capturedOptions = null;
+        A2AAgentHandler handler = CreateHandler(CreateStreamingAgentMockWithOptionsCapture(
+            options => capturedOptions = options));
+
+        // Act
+        await InvokeExecuteAsync(handler, new RequestContext
+        {
+            StreamingResponse = true,
+            TaskId = "",
+            ContextId = "ctx",
+            Message = new Message { MessageId = "test-id", Role = Role.User, Parts = [new Part { Text = "Hello" }] },
+            Metadata = new Dictionary<string, JsonElement>
+            {
+                ["key1"] = JsonSerializer.SerializeToElement("value1")
+            }
+        });
+
+        // Assert
+        Assert.NotNull(capturedOptions);
+        Assert.NotNull(capturedOptions.AdditionalProperties);
+        Assert.Equal("value1", capturedOptions.AdditionalProperties["key1"]?.ToString());
+    }
+
+    /// <summary>
+    /// Verifies that in streaming mode, when metadata is null, null options are passed to RunStreamingAsync.
+    /// </summary>
+    [Fact]
+    public async Task ExecuteAsync_Streaming_WithNullMetadata_PassesNullOptionsAsync()
+    {
+        // Arrange
+        AgentRunOptions? capturedOptions = null;
+        bool optionsCaptured = false;
+        A2AAgentHandler handler = CreateHandler(CreateStreamingAgentMockWithOptionsCapture(
+            options => { capturedOptions = options; optionsCaptured = true; }));
+
+        // Act
+        await InvokeExecuteAsync(handler, new RequestContext
+        {
+            StreamingResponse = true,
+            TaskId = "",
+            ContextId = "ctx",
+            Message = new Message { MessageId = "test-id", Role = Role.User, Parts = [new Part { Text = "Hello" }] }
+        });
+
+        // Assert
+        Assert.True(optionsCaptured);
+        Assert.Null(capturedOptions);
+    }
+
+    /// <summary>
+    /// Verifies that in streaming mode, ReferenceTaskIds throws NotSupportedException.
+    /// </summary>
+    [Fact]
+    public async Task ExecuteAsync_Streaming_WithReferenceTaskIds_ThrowsNotSupportedExceptionAsync()
+    {
+        // Arrange
+        A2AAgentHandler handler = CreateHandler(CreateStreamingAgentMock([]));
+
+        // Act & Assert
+        var eventQueue = new AgentEventQueue();
+        await Assert.ThrowsAsync<NotSupportedException>(() =>
+            handler.ExecuteAsync(
+                new RequestContext
+                {
+                    StreamingResponse = true,
+                    TaskId = "",
+                    ContextId = "ctx",
+                    Message = new Message
+                    {
+                        MessageId = "test-id",
+                        Role = Role.User,
+                        Parts = [new Part { Text = "Hello" }],
+                        ReferenceTaskIds = ["other-task-id"]
+                    }
+                },
+                eventQueue,
+                CancellationToken.None));
+    }
+
+    /// <summary>
+    /// Verifies that in streaming mode, when ContextId is null, a new one is generated.
+    /// </summary>
+    [Fact]
+    public async Task ExecuteAsync_Streaming_WhenContextIdIsNull_GeneratesContextIdAsync()
+    {
+        // Arrange
+        AgentResponseUpdate[] updates =
+        [
+            new AgentResponseUpdate(ChatRole.Assistant, "Reply") { ResponseId = "r1" }
+        ];
+        A2AAgentHandler handler = CreateHandler(CreateStreamingAgentMock(updates));
+
+        // Act
+        var events = await CollectEventsAsync(handler, new RequestContext
+        {
+            StreamingResponse = true,
+            TaskId = "",
+            ContextId = null!,
+            Message = new Message { MessageId = "test-id", Role = Role.User, Parts = [new Part { Text = "Hello" }] }
+        });
+
+        // Assert
+        Message message = Assert.Single(events.Messages);
+        Assert.NotNull(message.ContextId);
+        Assert.NotEmpty(message.ContextId);
+    }
+
+    /// <summary>
+    /// Verifies that in streaming mode, the provided ContextId is used in the response.
+    /// </summary>
+    [Fact]
+    public async Task ExecuteAsync_Streaming_UsesProvidedContextIdAsync()
+    {
+        // Arrange
+        AgentResponseUpdate[] updates =
+        [
+            new AgentResponseUpdate(ChatRole.Assistant, "Reply") { ResponseId = "r1" }
+        ];
+        A2AAgentHandler handler = CreateHandler(CreateStreamingAgentMock(updates));
+
+        // Act
+        var events = await CollectEventsAsync(handler, new RequestContext
+        {
+            StreamingResponse = true,
+            TaskId = "",
+            ContextId = "my-streaming-ctx",
+            Message = new Message { MessageId = "test-id", Role = Role.User, Parts = [new Part { Text = "Hello" }] }
+        });
+
+        // Assert
+        Message message = Assert.Single(events.Messages);
+        Assert.Equal("my-streaming-ctx", message.ContextId);
+    }
+
+    /// <summary>
+    /// Verifies that in streaming mode, when Message is null, the handler succeeds with empty messages.
+    /// </summary>
+    [Fact]
+    public async Task ExecuteAsync_Streaming_WhenMessageIsNull_SucceedsWithEmptyMessagesAsync()
+    {
+        // Arrange
+        AgentResponseUpdate[] updates =
+        [
+            new AgentResponseUpdate(ChatRole.Assistant, "Reply") { ResponseId = "r1" }
+        ];
+        A2AAgentHandler handler = CreateHandler(CreateStreamingAgentMock(updates));
+
+        // Act
+        var events = await CollectEventsAsync(handler, new RequestContext
+        {
+            StreamingResponse = true,
+            TaskId = "",
+            ContextId = "ctx",
+            Message = null!
+        });
+
+        // Assert
+        Message message = Assert.Single(events.Messages);
+        Assert.Equal("ctx", message.ContextId);
+    }
+
+    /// <summary>
+    /// Verifies that in streaming mode, the ResponseId from the update is used as the MessageId in the response.
+    /// </summary>
+    [Fact]
+    public async Task ExecuteAsync_Streaming_ResponseIdIsUsedAsMessageIdAsync()
+    {
+        // Arrange
+        AgentResponseUpdate[] updates =
+        [
+            new AgentResponseUpdate(ChatRole.Assistant, "chunk") { ResponseId = "resp-42" }
+        ];
+        A2AAgentHandler handler = CreateHandler(CreateStreamingAgentMock(updates));
+
+        // Act
+        var events = await CollectEventsAsync(handler, new RequestContext
+        {
+            StreamingResponse = true,
+            TaskId = "",
+            ContextId = "ctx",
+            Message = new Message { MessageId = "test-id", Role = Role.User, Parts = [new Part { Text = "Hello" }] }
+        });
+
+        // Assert
+        Message message = Assert.Single(events.Messages);
+        Assert.Equal("resp-42", message.MessageId);
+    }
+
+    /// <summary>
+    /// Verifies that in streaming mode, when ResponseId is null, a MessageId is still generated.
+    /// </summary>
+    [Fact]
+    public async Task ExecuteAsync_Streaming_WhenResponseIdIsNull_GeneratesMessageIdAsync()
+    {
+        // Arrange
+        AgentResponseUpdate[] updates =
+        [
+            new AgentResponseUpdate(ChatRole.Assistant, "chunk") { ResponseId = null }
+        ];
+        A2AAgentHandler handler = CreateHandler(CreateStreamingAgentMock(updates));
+
+        // Act
+        var events = await CollectEventsAsync(handler, new RequestContext
+        {
+            StreamingResponse = true,
+            TaskId = "",
+            ContextId = "ctx",
+            Message = new Message { MessageId = "test-id", Role = Role.User, Parts = [new Part { Text = "Hello" }] }
+        });
+
+        // Assert
+        Message message = Assert.Single(events.Messages);
+        Assert.NotNull(message.MessageId);
+        Assert.NotEmpty(message.MessageId);
+    }
+
+    /// <summary>
+    /// Verifies that in streaming mode, when the update has AdditionalProperties, the message has metadata.
+    /// </summary>
+    [Fact]
+    public async Task ExecuteAsync_Streaming_WithResponseAdditionalProperties_ReturnsMessageWithMetadataAsync()
+    {
+        // Arrange
+        AdditionalPropertiesDictionary additionalProps = new()
+        {
+            ["streamKey"] = "streamValue"
+        };
+        AgentResponseUpdate[] updates =
+        [
+            new AgentResponseUpdate(ChatRole.Assistant, "chunk") { ResponseId = "r1", AdditionalProperties = additionalProps }
+        ];
+        A2AAgentHandler handler = CreateHandler(CreateStreamingAgentMock(updates));
+
+        // Act
+        var events = await CollectEventsAsync(handler, new RequestContext
+        {
+            StreamingResponse = true,
+            TaskId = "",
+            ContextId = "ctx",
+            Message = new Message { MessageId = "test-id", Role = Role.User, Parts = [new Part { Text = "Hello" }] }
+        });
+
+        // Assert
+        Message message = Assert.Single(events.Messages);
+        Assert.NotNull(message.Metadata);
+        Assert.True(message.Metadata.ContainsKey("streamKey"));
+    }
+
+    /// <summary>
+    /// Verifies that in streaming mode, when the update has null AdditionalProperties, the message has null metadata.
+    /// </summary>
+    [Fact]
+    public async Task ExecuteAsync_Streaming_WithNullAdditionalProperties_ReturnsMessageWithNullMetadataAsync()
+    {
+        // Arrange
+        AgentResponseUpdate[] updates =
+        [
+            new AgentResponseUpdate(ChatRole.Assistant, "chunk") { ResponseId = "r1", AdditionalProperties = null }
+        ];
+        A2AAgentHandler handler = CreateHandler(CreateStreamingAgentMock(updates));
+
+        // Act
+        var events = await CollectEventsAsync(handler, new RequestContext
+        {
+            StreamingResponse = true,
+            TaskId = "",
+            ContextId = "ctx",
+            Message = new Message { MessageId = "test-id", Role = Role.User, Parts = [new Part { Text = "Hello" }] }
+        });
+
+        // Assert
+        Message message = Assert.Single(events.Messages);
+        Assert.Null(message.Metadata);
+    }
+
+    /// <summary>
+    /// Verifies that in streaming mode, the session is saved after all updates are processed.
+    /// </summary>
+    [Fact]
+    public async Task ExecuteAsync_Streaming_SavesSessionAfterProcessingAsync()
+    {
+        // Arrange
+        var mockSessionStore = new Mock<AgentSessionStore>();
+        mockSessionStore
+            .Setup(x => x.GetSessionAsync(
+                It.IsAny<AIAgent>(),
+                It.IsAny<string>(),
+                It.IsAny<CancellationToken>()))
+            .ReturnsAsync(new TestAgentSession());
+        mockSessionStore
+            .Setup(x => x.SaveSessionAsync(
+                It.IsAny<AIAgent>(),
+                It.IsAny<string>(),
+                It.IsAny<AgentSession>(),
+                It.IsAny<CancellationToken>()))
+            .Returns(ValueTask.CompletedTask);
+
+        AgentResponseUpdate[] updates =
+        [
+            new AgentResponseUpdate(ChatRole.Assistant, "chunk") { ResponseId = "r1" }
+        ];
+        A2AAgentHandler handler = CreateHandler(CreateStreamingAgentMock(updates), agentSessionStore: mockSessionStore.Object);
+
+        // Act
+        await InvokeExecuteAsync(handler, new RequestContext
+        {
+            StreamingResponse = true,
+            TaskId = "",
+            ContextId = "ctx-stream",
+            Message = new Message { MessageId = "test-id", Role = Role.User, Parts = [new Part { Text = "Hello" }] }
+        });
+
+        // Assert - verify session was saved
+        mockSessionStore.Verify(
+            x => x.SaveSessionAsync(
+                It.IsAny<AIAgent>(),
+                It.Is<string>(s => s == "ctx-stream"),
+                It.IsAny<AgentSession>(),
+                It.IsAny<CancellationToken>()),
+            Times.Once);
+    }
+
+    /// <summary>
+    /// Verifies that in streaming mode, when RunStreamingAsync yields no updates,
+    /// no messages are enqueued and the session is still saved.
+    /// </summary>
+    [Fact]
+    public async Task ExecuteAsync_Streaming_WhenNoUpdates_EnqueuesNoMessagesAndSavesSessionAsync()
+    {
+        // Arrange
+        var mockSessionStore = new Mock<AgentSessionStore>();
+        mockSessionStore
+            .Setup(x => x.GetSessionAsync(
+                It.IsAny<AIAgent>(),
+                It.IsAny<string>(),
+                It.IsAny<CancellationToken>()))
+            .ReturnsAsync(new TestAgentSession());
+        mockSessionStore
+            .Setup(x => x.SaveSessionAsync(
+                It.IsAny<AIAgent>(),
+                It.IsAny<string>(),
+                It.IsAny<AgentSession>(),
+                It.IsAny<CancellationToken>()))
+            .Returns(ValueTask.CompletedTask);
+
+        A2AAgentHandler handler = CreateHandler(CreateStreamingAgentMock([]), agentSessionStore: mockSessionStore.Object);
+
+        // Act
+        var events = await CollectEventsAsync(handler, new RequestContext
+        {
+            StreamingResponse = true,
+            TaskId = "",
+            ContextId = "ctx",
+            Message = new Message { MessageId = "test-id", Role = Role.User, Parts = [new Part { Text = "Hello" }] }
+        });
+
+        // Assert
+        Assert.Empty(events.Messages);
+        mockSessionStore.Verify(
+            x => x.SaveSessionAsync(
+                It.IsAny<AIAgent>(),
+                It.Is<string>(s => s == "ctx"),
+                It.IsAny<AgentSession>(),
+                It.IsAny<CancellationToken>()),
+            Times.Once);
+    }
+
+    /// <summary>
+    /// Verifies that the CancellationToken is propagated to RunStreamingAsync in the streaming path.
+    /// </summary>
+    [Fact]
+    public async Task ExecuteAsync_Streaming_CancellationTokenIsPropagatedToRunStreamingAsync()
+    {
+        // Arrange
+        CancellationToken capturedToken = default;
+        using var cts = new CancellationTokenSource();
+
+        Mock<AIAgent> agentMock = new() { CallBase = true };
+        agentMock.SetupGet(x => x.Name).Returns("TestAgent");
+        agentMock
+            .Protected()
+            .Setup<ValueTask<AgentSession>>("CreateSessionCoreAsync", ItExpr.IsAny<CancellationToken>())
+            .ReturnsAsync(new TestAgentSession());
+        agentMock
+            .Protected()
+            .Setup<IAsyncEnumerable<AgentResponseUpdate>>("RunCoreStreamingAsync",
+                ItExpr.IsAny<IEnumerable<ChatMessage>>(),
+                ItExpr.IsAny<AgentSession?>(),
+                ItExpr.IsAny<AgentRunOptions?>(),
+                ItExpr.IsAny<CancellationToken>())
+            .Callback<IEnumerable<ChatMessage>, AgentSession?, AgentRunOptions?, CancellationToken>(
+                (_, _, _, ct) => capturedToken = ct)
+            .Returns(() => ToAsyncEnumerableAsync([new AgentResponseUpdate(ChatRole.Assistant, "reply") { ResponseId = "r1" }]));
+
+        A2AAgentHandler handler = CreateHandler(agentMock);
+
+        // Act
+        var eventQueue = new AgentEventQueue();
+        await handler.ExecuteAsync(
+            new RequestContext
+            {
+                TaskId = "",
+                ContextId = "ctx",
+                StreamingResponse = true,
+                Message = new Message { MessageId = "test-id", Role = Role.User, Parts = [new Part { Text = "Hello" }] }
+            },
+            eventQueue,
+            cts.Token);
+        eventQueue.Complete(null);
+
+        // Assert
+        Assert.Equal(cts.Token, capturedToken);
+    }
+
     /// <summary>
     /// Verifies that when no session store is provided, the handler uses InMemoryAgentSessionStore
     /// and can execute successfully.
@@ -656,169 +1107,471 @@ public async Task Handler_WithCustomSessionStore_UsesProvidedSessionStoreAsync()
             }
         });
 
-        // Assert - verify the custom session store was called
-        mockSessionStore.Verify(
-            x => x.GetSessionAsync(
-                It.IsAny<AIAgent>(),
-                It.Is<string>(s => s == "ctx-1"),
-                It.IsAny<CancellationToken>()),
-            Times.Once);
+        // Assert - verify the custom session store was called
+        mockSessionStore.Verify(
+            x => x.GetSessionAsync(
+                It.IsAny<AIAgent>(),
+                It.Is<string>(s => s == "ctx-1"),
+                It.IsAny<CancellationToken>()),
+            Times.Once);
+        mockSessionStore.Verify(
+            x => x.SaveSessionAsync(
+                It.IsAny<AIAgent>(),
+                It.Is<string>(s => s == "ctx-1"),
+                It.IsAny<AgentSession>(),
+                It.IsAny<CancellationToken>()),
+            Times.Once);
+    }
+
+    /// <summary>
+    /// Verifies that when no session store is provided, the default InMemoryAgentSessionStore
+    /// persists sessions across multiple calls with the same context ID.
+    /// </summary>
+    [Fact]
+    public async Task Handler_WithNullSessionStore_SessionIsPersistedAcrossCallsAsync()
+    {
+        // Arrange - track how many times CreateSessionCoreAsync is called
+        int createSessionCallCount = 0;
+        var sessionInstance = new TestAgentSession();
+
+        Mock<AIAgent> agentMock = new() { CallBase = true };
+        agentMock.SetupGet(x => x.Name).Returns("TestAgent");
+        agentMock
+            .Protected()
+            .Setup<ValueTask<AgentSession>>("CreateSessionCoreAsync", ItExpr.IsAny<CancellationToken>())
+            .Callback(() => Interlocked.Increment(ref createSessionCallCount))
+            .ReturnsAsync(() => new TestAgentSession());
+        agentMock
+            .Protected()
+            .Setup<ValueTask<JsonElement>>("SerializeSessionCoreAsync",
+                ItExpr.IsAny<AgentSession>(),
+                ItExpr.IsAny<JsonSerializerOptions?>(),
+                ItExpr.IsAny<CancellationToken>())
+            .ReturnsAsync(JsonDocument.Parse("{}").RootElement);
+        agentMock
+            .Protected()
+            .Setup<ValueTask<AgentSession>>("DeserializeSessionCoreAsync",
+                ItExpr.IsAny<JsonElement>(),
+                ItExpr.IsAny<JsonSerializerOptions?>(),
+                ItExpr.IsAny<CancellationToken>())
+            .ReturnsAsync(sessionInstance);
+        agentMock
+            .Protected()
+            .Setup<Task<AgentResponse>>("RunCoreAsync",
+                ItExpr.IsAny<IEnumerable<ChatMessage>>(),
+                ItExpr.IsAny<AgentSession?>(),
+                ItExpr.IsAny<AgentRunOptions?>(),
+                ItExpr.IsAny<CancellationToken>())
+            .ReturnsAsync(new AgentResponse([new ChatMessage(ChatRole.Assistant, "Reply")]));
+
+        A2AAgentHandler handler = CreateHandler(agentMock, agentSessionStore: null);
+
+        var context = new RequestContext
+        {
+            StreamingResponse = false,
+            TaskId = "",
+            ContextId = "ctx-persistent",
+            Message = new Message
+            {
+                MessageId = "test-id",
+                Role = Role.User,
+                Parts = [new Part { Text = "Hello" }]
+            }
+        };
+
+        // Act - call twice with the same context ID
+        await InvokeExecuteAsync(handler, context);
+        await InvokeExecuteAsync(handler, context);
+
+        // Assert - CreateSessionCoreAsync should be called once (first call creates, second retrieves from store)
+        Assert.Equal(1, createSessionCallCount);
+    }
+
+    /// <summary>
+    /// Verifies that when the AllowBackgroundWhen delegate throws, the exception propagates
+    /// and the agent is not invoked.
+    /// </summary>
+    [Fact]
+    public async Task ExecuteAsync_DynamicMode_WhenCallbackThrows_PropagatesExceptionAsync()
+    {
+        // Arrange
+        bool agentInvoked = false;
+        A2AAgentHandler handler = CreateHandler(
+            CreateAgentMock(_ => agentInvoked = true),
+            runMode: AgentRunMode.AllowBackgroundWhen((_, _) =>
+                throw new InvalidOperationException("Callback failed")));
+
+        // Act & Assert
+        await Assert.ThrowsAsync<InvalidOperationException>(() =>
+            InvokeExecuteAsync(handler, new RequestContext
+            {
+                TaskId = "", ContextId = "ctx", StreamingResponse = false, Message = new Message { MessageId = "test-id", Role = Role.User, Parts = [new Part { Text = "Hello" }] }
+            }));
+
+        Assert.False(agentInvoked);
+    }
+
+    /// <summary>
+    /// Verifies that the CancellationToken is propagated to the AllowBackgroundWhen delegate.
+    /// </summary>
+    [Fact]
+    public async Task ExecuteAsync_DynamicMode_CancellationTokenIsPropagatedToCallbackAsync()
+    {
+        // Arrange
+        CancellationToken capturedToken = default;
+        using var cts = new CancellationTokenSource();
+        A2AAgentHandler handler = CreateHandler(
+            CreateAgentMock(_ => { }),
+            runMode: AgentRunMode.AllowBackgroundWhen((_, ct) =>
+            {
+                capturedToken = ct;
+                return ValueTask.FromResult(false);
+            }));
+
+        // Act
+        var eventQueue = new AgentEventQueue();
+        await handler.ExecuteAsync(
+            new RequestContext
+            {
+                TaskId = "", ContextId = "ctx", StreamingResponse = false, Message = new Message { MessageId = "test-id", Role = Role.User, Parts = [new Part { Text = "Hello" }] }
+            },
+            eventQueue,
+            cts.Token);
+        eventQueue.Complete(null);
+
+        // Assert
+        Assert.Equal(cts.Token, capturedToken);
+    }
+
+    /// <summary>
+    /// Verifies that the agent run mode is applied on the continuation/task-update path,
+    /// not just the new message path.
+    /// </summary>
+    [Fact]
+    public async Task ExecuteAsync_OnContinuation_RunModeIsAppliedAsync()
+    {
+        // Arrange
+        AgentRunOptions? capturedOptions = null;
+        A2AAgentHandler handler = CreateHandler(
+            CreateAgentMock(options => capturedOptions = options),
+            runMode: AgentRunMode.AllowBackgroundIfSupported);
+
+        // Act
+        await InvokeExecuteAsync(handler, new RequestContext
+        {
+            StreamingResponse = false,
+            TaskId = "task-1",
+            ContextId = "ctx-1",
+            Message = new Message { MessageId = "empty", Role = Role.User, Parts = [] },
+
+            Task = new AgentTask { Id = "task-1", ContextId = "ctx-1", History = [new Message { Role = Role.User, Parts = [new Part { Text = "Hello" }] }] }
+        });
+
+        // Assert
+        Assert.NotNull(capturedOptions);
+        Assert.True(capturedOptions.AllowBackgroundResponses);
+    }
+
+    /// <summary>
+    /// Verifies that in the non-streaming path, SaveSessionAsync is called with
+    /// CancellationToken.None even when RunAsync throws an exception.
+    /// </summary>
+    [Fact]
+    public async Task ExecuteAsync_NonStreaming_WhenRunAsyncThrows_SavesSessionWithUncancelledTokenAsync()
+    {
+        // Arrange
+        var mockSessionStore = new Mock<AgentSessionStore>();
+        mockSessionStore
+            .Setup(x => x.GetSessionAsync(It.IsAny<AIAgent>(), It.IsAny<string>(), It.IsAny<CancellationToken>()))
+            .ReturnsAsync(new TestAgentSession());
+        mockSessionStore
+            .Setup(x => x.SaveSessionAsync(It.IsAny<AIAgent>(), It.IsAny<string>(), It.IsAny<AgentSession>(), It.IsAny<CancellationToken>()))
+            .Returns(ValueTask.CompletedTask);
+
+        Mock<AIAgent> agentMock = new() { CallBase = true };
+        agentMock.SetupGet(x => x.Name).Returns("TestAgent");
+        agentMock.Protected()
+            .Setup<ValueTask<AgentSession>>("CreateSessionCoreAsync", ItExpr.IsAny<CancellationToken>())
+            .ReturnsAsync(new TestAgentSession());
+        agentMock.Protected()
+            .Setup<Task<AgentResponse>>("RunCoreAsync",
+                ItExpr.IsAny<IEnumerable<ChatMessage>>(),
+                ItExpr.IsAny<AgentSession?>(),
+                ItExpr.IsAny<AgentRunOptions?>(),
+                ItExpr.IsAny<CancellationToken>())
+            .ThrowsAsync(new InvalidOperationException("Agent failed"));
+
+        using var cts = new CancellationTokenSource();
+        A2AAgentHandler handler = CreateHandler(agentMock, agentSessionStore: mockSessionStore.Object);
+
+        // Act
+        var eventQueue = new AgentEventQueue();
+        await Assert.ThrowsAsync<InvalidOperationException>(() =>
+            handler.ExecuteAsync(
+                new RequestContext
+                {
+                    TaskId = "", ContextId = "ctx", StreamingResponse = false,
+                    Message = new Message { MessageId = "test-id", Role = Role.User, Parts = [new Part { Text = "Hello" }] }
+                },
+                eventQueue,
+                cts.Token));
+
+        // Assert - SaveSessionAsync was called with CancellationToken.None despite the exception
+        mockSessionStore.Verify(
+            x => x.SaveSessionAsync(
+                It.IsAny<AIAgent>(),
+                It.Is<string>(s => s == "ctx"),
+                It.IsAny<AgentSession>(),
+                It.Is<CancellationToken>(ct => ct == CancellationToken.None)),
+            Times.Once);
+    }
+
+    /// <summary>
+    /// Verifies that in the streaming path, SaveSessionAsync is called with
+    /// CancellationToken.None even when RunStreamingAsync throws an exception.
+    /// </summary>
+    [Fact]
+    public async Task ExecuteAsync_Streaming_WhenRunStreamingAsyncThrows_SavesSessionWithUncancelledTokenAsync()
+    {
+        // Arrange
+        var mockSessionStore = new Mock<AgentSessionStore>();
+        mockSessionStore
+            .Setup(x => x.GetSessionAsync(It.IsAny<AIAgent>(), It.IsAny<string>(), It.IsAny<CancellationToken>()))
+            .ReturnsAsync(new TestAgentSession());
+        mockSessionStore
+            .Setup(x => x.SaveSessionAsync(It.IsAny<AIAgent>(), It.IsAny<string>(), It.IsAny<AgentSession>(), It.IsAny<CancellationToken>()))
+            .Returns(ValueTask.CompletedTask);
+
+        Mock<AIAgent> agentMock = new() { CallBase = true };
+        agentMock.SetupGet(x => x.Name).Returns("TestAgent");
+        agentMock.Protected()
+            .Setup<ValueTask<AgentSession>>("CreateSessionCoreAsync", ItExpr.IsAny<CancellationToken>())
+            .ReturnsAsync(new TestAgentSession());
+        agentMock.Protected()
+            .Setup<IAsyncEnumerable<AgentResponseUpdate>>("RunCoreStreamingAsync",
+                ItExpr.IsAny<IEnumerable<ChatMessage>>(),
+                ItExpr.IsAny<AgentSession?>(),
+                ItExpr.IsAny<AgentRunOptions?>(),
+                ItExpr.IsAny<CancellationToken>())
+            .Returns(() => ToThrowingAsyncEnumerableAsync(new InvalidOperationException("Stream failed")));
+
+        using var cts = new CancellationTokenSource();
+        A2AAgentHandler handler = CreateHandler(agentMock, agentSessionStore: mockSessionStore.Object);
+
+        // Act
+        var eventQueue = new AgentEventQueue();
+        await Assert.ThrowsAsync<InvalidOperationException>(() =>
+            handler.ExecuteAsync(
+                new RequestContext
+                {
+                    TaskId = "", ContextId = "ctx-stream", StreamingResponse = true,
+                    Message = new Message { MessageId = "test-id", Role = Role.User, Parts = [new Part { Text = "Hello" }] }
+                },
+                eventQueue,
+                cts.Token));
+
+        // Assert - SaveSessionAsync was called with CancellationToken.None despite the exception
         mockSessionStore.Verify(
             x => x.SaveSessionAsync(
                 It.IsAny<AIAgent>(),
-                It.Is<string>(s => s == "ctx-1"),
+                It.Is<string>(s => s == "ctx-stream"),
                 It.IsAny<AgentSession>(),
-                It.IsAny<CancellationToken>()),
+                It.Is<CancellationToken>(ct => ct == CancellationToken.None)),
             Times.Once);
     }
 
     /// <summary>
-    /// Verifies that when no session store is provided, the default InMemoryAgentSessionStore
-    /// persists sessions across multiple calls with the same context ID.
+    /// Verifies that on the continuation path, SaveSessionAsync is called with
+    /// CancellationToken.None even when RunAsync throws an exception.
     /// </summary>
     [Fact]
-    public async Task Handler_WithNullSessionStore_SessionIsPersistedAcrossCallsAsync()
+    public async Task ExecuteAsync_OnContinuation_WhenRunAsyncThrows_SavesSessionWithUncancelledTokenAsync()
     {
-        // Arrange - track how many times CreateSessionCoreAsync is called
-        int createSessionCallCount = 0;
-        var sessionInstance = new TestAgentSession();
+        // Arrange
+        var mockSessionStore = new Mock<AgentSessionStore>();
+        mockSessionStore
+            .Setup(x => x.GetSessionAsync(It.IsAny<AIAgent>(), It.IsAny<string>(), It.IsAny<CancellationToken>()))
+            .ReturnsAsync(new TestAgentSession());
+        mockSessionStore
+            .Setup(x => x.SaveSessionAsync(It.IsAny<AIAgent>(), It.IsAny<string>(), It.IsAny<AgentSession>(), It.IsAny<CancellationToken>()))
+            .Returns(ValueTask.CompletedTask);
 
         Mock<AIAgent> agentMock = new() { CallBase = true };
         agentMock.SetupGet(x => x.Name).Returns("TestAgent");
-        agentMock
-            .Protected()
+        agentMock.Protected()
             .Setup<ValueTask<AgentSession>>("CreateSessionCoreAsync", ItExpr.IsAny<CancellationToken>())
-            .Callback(() => Interlocked.Increment(ref createSessionCallCount))
-            .ReturnsAsync(() => new TestAgentSession());
-        agentMock
-            .Protected()
-            .Setup<ValueTask<JsonElement>>("SerializeSessionCoreAsync",
-                ItExpr.IsAny<AgentSession>(),
-                ItExpr.IsAny<JsonSerializerOptions?>(),
-                ItExpr.IsAny<CancellationToken>())
-            .ReturnsAsync(JsonDocument.Parse("{}").RootElement);
-        agentMock
-            .Protected()
-            .Setup<ValueTask<AgentSession>>("DeserializeSessionCoreAsync",
-                ItExpr.IsAny<JsonElement>(),
-                ItExpr.IsAny<JsonSerializerOptions?>(),
-                ItExpr.IsAny<CancellationToken>())
-            .ReturnsAsync(sessionInstance);
-        agentMock
-            .Protected()
+            .ReturnsAsync(new TestAgentSession());
+        agentMock.Protected()
             .Setup<Task<AgentResponse>>("RunCoreAsync",
                 ItExpr.IsAny<IEnumerable<ChatMessage>>(),
                 ItExpr.IsAny<AgentSession?>(),
                 ItExpr.IsAny<AgentRunOptions?>(),
                 ItExpr.IsAny<CancellationToken>())
-            .ReturnsAsync(new AgentResponse([new ChatMessage(ChatRole.Assistant, "Reply")]));
-
-        A2AAgentHandler handler = CreateHandler(agentMock, agentSessionStore: null);
+            .ThrowsAsync(new InvalidOperationException("Agent failed"));
 
-        var context = new RequestContext
-        {
-            StreamingResponse = false,
-            TaskId = "",
-            ContextId = "ctx-persistent",
-            Message = new Message
-            {
-                MessageId = "test-id",
-                Role = Role.User,
-                Parts = [new Part { Text = "Hello" }]
-            }
-        };
+        using var cts = new CancellationTokenSource();
+        A2AAgentHandler handler = CreateHandler(agentMock, agentSessionStore: mockSessionStore.Object);
 
-        // Act - call twice with the same context ID
-        await InvokeExecuteAsync(handler, context);
-        await InvokeExecuteAsync(handler, context);
+        // Act
+        var eventQueue = new AgentEventQueue();
+        var events = new EventCollector();
+        var readerTask = ReadEventsAsync(eventQueue, events);
+        await Assert.ThrowsAsync<InvalidOperationException>(() =>
+            handler.ExecuteAsync(
+                new RequestContext
+                {
+                    StreamingResponse = false,
+                    TaskId = "task-1", ContextId = "ctx-cont",
+                    Message = new Message { MessageId = "empty", Role = Role.User, Parts = [] },
+                    Task = new AgentTask { Id = "task-1", ContextId = "ctx-cont", History = [new Message { Role = Role.User, Parts = [new Part { Text = "Hello" }] }] }
+                },
+                eventQueue,
+                cts.Token));
+        eventQueue.Complete(null);
+        await readerTask;
 
-        // Assert - CreateSessionCoreAsync should be called once (first call creates, second retrieves from store)
-        Assert.Equal(1, createSessionCallCount);
+        // Assert - SaveSessionAsync was called with CancellationToken.None despite the exception
+        mockSessionStore.Verify(
+            x => x.SaveSessionAsync(
+                It.IsAny<AIAgent>(),
+                It.Is<string>(s => s == "ctx-cont"),
+                It.IsAny<AgentSession>(),
+                It.Is<CancellationToken>(ct => ct == CancellationToken.None)),
+            Times.Once);
     }
 
     /// <summary>
-    /// Verifies that when the AllowBackgroundWhen delegate throws, the exception propagates
-    /// and the agent is not invoked.
+    /// Verifies that in the non-streaming path, SaveSessionAsync is called with
+    /// CancellationToken.None rather than the caller's cancellation token.
     /// </summary>
     [Fact]
-    public async Task ExecuteAsync_DynamicMode_WhenCallbackThrows_PropagatesExceptionAsync()
+    public async Task ExecuteAsync_NonStreaming_SavesSessionWithUncancelledTokenAsync()
     {
         // Arrange
-        bool agentInvoked = false;
-        A2AAgentHandler handler = CreateHandler(
-            CreateAgentMock(_ => agentInvoked = true),
-            runMode: AgentRunMode.AllowBackgroundWhen((_, _) =>
-                throw new InvalidOperationException("Callback failed")));
+        var mockSessionStore = new Mock<AgentSessionStore>();
+        mockSessionStore
+            .Setup(x => x.GetSessionAsync(It.IsAny<AIAgent>(), It.IsAny<string>(), It.IsAny<CancellationToken>()))
+            .ReturnsAsync(new TestAgentSession());
+        mockSessionStore
+            .Setup(x => x.SaveSessionAsync(It.IsAny<AIAgent>(), It.IsAny<string>(), It.IsAny<AgentSession>(), It.IsAny<CancellationToken>()))
+            .Returns(ValueTask.CompletedTask);
 
-        // Act & Assert
-        await Assert.ThrowsAsync<InvalidOperationException>(() =>
-            InvokeExecuteAsync(handler, new RequestContext
+        AgentResponse response = new([new ChatMessage(ChatRole.Assistant, "Reply")]);
+        A2AAgentHandler handler = CreateHandler(CreateAgentMockWithResponse(response), agentSessionStore: mockSessionStore.Object);
+
+        using var cts = new CancellationTokenSource();
+
+        // Act
+        var eventQueue = new AgentEventQueue();
+        await handler.ExecuteAsync(
+            new RequestContext
             {
-                TaskId = "", ContextId = "ctx", StreamingResponse = false, Message = new Message { MessageId = "test-id", Role = Role.User, Parts = [new Part { Text = "Hello" }] }
-            }));
+                TaskId = "", ContextId = "ctx", StreamingResponse = false,
+                Message = new Message { MessageId = "test-id", Role = Role.User, Parts = [new Part { Text = "Hello" }] }
+            },
+            eventQueue,
+            cts.Token);
+        eventQueue.Complete(null);
 
-        Assert.False(agentInvoked);
+        // Assert - SaveSessionAsync was called with CancellationToken.None, not the caller's token
+        mockSessionStore.Verify(
+            x => x.SaveSessionAsync(
+                It.IsAny<AIAgent>(),
+                It.Is<string>(s => s == "ctx"),
+                It.IsAny<AgentSession>(),
+                It.Is<CancellationToken>(ct => ct == CancellationToken.None)),
+            Times.Once);
     }
 
     /// <summary>
-    /// Verifies that the CancellationToken is propagated to the AllowBackgroundWhen delegate.
+    /// Verifies that in the streaming path, SaveSessionAsync is called with
+    /// CancellationToken.None rather than the caller's cancellation token.
     /// </summary>
     [Fact]
-    public async Task ExecuteAsync_DynamicMode_CancellationTokenIsPropagatedToCallbackAsync()
+    public async Task ExecuteAsync_Streaming_SavesSessionWithUncancelledTokenAsync()
     {
         // Arrange
-        CancellationToken capturedToken = default;
+        var mockSessionStore = new Mock<AgentSessionStore>();
+        mockSessionStore
+            .Setup(x => x.GetSessionAsync(It.IsAny<AIAgent>(), It.IsAny<string>(), It.IsAny<CancellationToken>()))
+            .ReturnsAsync(new TestAgentSession());
+        mockSessionStore
+            .Setup(x => x.SaveSessionAsync(It.IsAny<AIAgent>(), It.IsAny<string>(), It.IsAny<AgentSession>(), It.IsAny<CancellationToken>()))
+            .Returns(ValueTask.CompletedTask);
+
+        AgentResponseUpdate[] updates = [new AgentResponseUpdate(ChatRole.Assistant, "chunk") { ResponseId = "r1" }];
+        A2AAgentHandler handler = CreateHandler(CreateStreamingAgentMock(updates), agentSessionStore: mockSessionStore.Object);
+
         using var cts = new CancellationTokenSource();
-        A2AAgentHandler handler = CreateHandler(
-            CreateAgentMock(_ => { }),
-            runMode: AgentRunMode.AllowBackgroundWhen((_, ct) =>
-            {
-                capturedToken = ct;
-                return ValueTask.FromResult(false);
-            }));
 
         // Act
         var eventQueue = new AgentEventQueue();
         await handler.ExecuteAsync(
             new RequestContext
             {
-                TaskId = "", ContextId = "ctx", StreamingResponse = false, Message = new Message { MessageId = "test-id", Role = Role.User, Parts = [new Part { Text = "Hello" }] }
+                TaskId = "", ContextId = "ctx-stream", StreamingResponse = true,
+                Message = new Message { MessageId = "test-id", Role = Role.User, Parts = [new Part { Text = "Hello" }] }
             },
             eventQueue,
             cts.Token);
         eventQueue.Complete(null);
 
-        // Assert
-        Assert.Equal(cts.Token, capturedToken);
+        // Assert - SaveSessionAsync was called with CancellationToken.None, not the caller's token
+        mockSessionStore.Verify(
+            x => x.SaveSessionAsync(
+                It.IsAny<AIAgent>(),
+                It.Is<string>(s => s == "ctx-stream"),
+                It.IsAny<AgentSession>(),
+                It.Is<CancellationToken>(ct => ct == CancellationToken.None)),
+            Times.Once);
     }
 
     /// <summary>
-    /// Verifies that the agent run mode is applied on the continuation/task-update path,
-    /// not just the new message path.
+    /// Verifies that on the continuation path, SaveSessionAsync is called with
+    /// CancellationToken.None rather than the caller's cancellation token.
     /// </summary>
     [Fact]
-    public async Task ExecuteAsync_OnContinuation_RunModeIsAppliedAsync()
+    public async Task ExecuteAsync_OnContinuation_SavesSessionWithUncancelledTokenAsync()
     {
         // Arrange
-        AgentRunOptions? capturedOptions = null;
-        A2AAgentHandler handler = CreateHandler(
-            CreateAgentMock(options => capturedOptions = options),
-            runMode: AgentRunMode.AllowBackgroundIfSupported);
+        var mockSessionStore = new Mock<AgentSessionStore>();
+        mockSessionStore
+            .Setup(x => x.GetSessionAsync(It.IsAny<AIAgent>(), It.IsAny<string>(), It.IsAny<CancellationToken>()))
+            .ReturnsAsync(new TestAgentSession());
+        mockSessionStore
+            .Setup(x => x.SaveSessionAsync(It.IsAny<AIAgent>(), It.IsAny<string>(), It.IsAny<AgentSession>(), It.IsAny<CancellationToken>()))
+            .Returns(ValueTask.CompletedTask);
 
-        // Act
-        await InvokeExecuteAsync(handler, new RequestContext
-        {
-            StreamingResponse = false,
-            TaskId = "task-1",
-            ContextId = "ctx-1",
-            Message = new Message { MessageId = "empty", Role = Role.User, Parts = [] },
+        AgentResponse response = new([new ChatMessage(ChatRole.Assistant, "Done!")]);
+        A2AAgentHandler handler = CreateHandler(CreateAgentMockWithResponse(response), agentSessionStore: mockSessionStore.Object);
 
-            Task = new AgentTask { Id = "task-1", ContextId = "ctx-1", History = [new Message { Role = Role.User, Parts = [new Part { Text = "Hello" }] }] }
-        });
+        using var cts = new CancellationTokenSource();
 
-        // Assert
-        Assert.NotNull(capturedOptions);
-        Assert.True(capturedOptions.AllowBackgroundResponses);
+        // Act
+        var eventQueue = new AgentEventQueue();
+        var events = new EventCollector();
+        var readerTask = ReadEventsAsync(eventQueue, events);
+        await handler.ExecuteAsync(
+            new RequestContext
+            {
+                StreamingResponse = false,
+                TaskId = "task-1", ContextId = "ctx-cont",
+                Message = new Message { MessageId = "empty", Role = Role.User, Parts = [] },
+                Task = new AgentTask { Id = "task-1", ContextId = "ctx-cont", History = [new Message { Role = Role.User, Parts = [new Part { Text = "Hello" }] }] }
+            },
+            eventQueue,
+            cts.Token);
+        eventQueue.Complete(null);
+        await readerTask;
+
+        // Assert - SaveSessionAsync was called with CancellationToken.None, not the caller's token
+        mockSessionStore.Verify(
+            x => x.SaveSessionAsync(
+                It.IsAny<AIAgent>(),
+                It.Is<string>(s => s == "ctx-cont"),
+                It.IsAny<AgentSession>(),
+                It.Is<CancellationToken>(ct => ct == CancellationToken.None)),
+            Times.Once);
     }
 
     private static A2AAgentHandler CreateHandler(
@@ -905,6 +1658,68 @@ private static Mock<AIAgent> CreateAgentMockWithCallCount(
         return agentMock;
     }
 
+    private static Mock<AIAgent> CreateStreamingAgentMock(IEnumerable<AgentResponseUpdate> updates)
+    {
+        Mock<AIAgent> agentMock = new() { CallBase = true };
+        agentMock.SetupGet(x => x.Name).Returns("TestAgent");
+        agentMock
+            .Protected()
+            .Setup<ValueTask<AgentSession>>("CreateSessionCoreAsync", ItExpr.IsAny<CancellationToken>())
+            .ReturnsAsync(new TestAgentSession());
+        agentMock
+            .Protected()
+            .Setup<IAsyncEnumerable<AgentResponseUpdate>>("RunCoreStreamingAsync",
+                ItExpr.IsAny<IEnumerable<ChatMessage>>(),
+                ItExpr.IsAny<AgentSession?>(),
+                ItExpr.IsAny<AgentRunOptions?>(),
+                ItExpr.IsAny<CancellationToken>())
+            .Returns(() => ToAsyncEnumerableAsync(updates));
+
+        return agentMock;
+    }
+
+    private static Mock<AIAgent> CreateStreamingAgentMockWithOptionsCapture(
+        Action<AgentRunOptions?> optionsCallback)
+    {
+        Mock<AIAgent> agentMock = new() { CallBase = true };
+        agentMock.SetupGet(x => x.Name).Returns("TestAgent");
+        agentMock
+            .Protected()
+            .Setup<ValueTask<AgentSession>>("CreateSessionCoreAsync", ItExpr.IsAny<CancellationToken>())
+            .ReturnsAsync(new TestAgentSession());
+        agentMock
+            .Protected()
+            .Setup<IAsyncEnumerable<AgentResponseUpdate>>("RunCoreStreamingAsync",
+                ItExpr.IsAny<IEnumerable<ChatMessage>>(),
+                ItExpr.IsAny<AgentSession?>(),
+                ItExpr.IsAny<AgentRunOptions?>(),
+                ItExpr.IsAny<CancellationToken>())
+            .Callback<IEnumerable<ChatMessage>, AgentSession?, AgentRunOptions?, CancellationToken>(
+                (_, _, options, _) => optionsCallback(options))
+            .Returns(() => ToAsyncEnumerableAsync([new AgentResponseUpdate(ChatRole.Assistant, "reply") { ResponseId = "r1" }]));
+
+        return agentMock;
+    }
+
+    private static async IAsyncEnumerable<T> ToAsyncEnumerableAsync<T>(IEnumerable<T> items)
+    {
+        await Task.Yield();
+        foreach (var item in items)
+        {
+            yield return item;
+        }
+    }
+
+    private static async IAsyncEnumerable<AgentResponseUpdate> ToThrowingAsyncEnumerableAsync(Exception exception)
+    {
+        await Task.Yield();
+        throw exception;
+
+#pragma warning disable CS0162 // Unreachable code detected - yield is required for async iterator
+        yield break;
+#pragma warning restore CS0162
+    }
+
     private static async Task InvokeExecuteAsync(A2AAgentHandler handler, RequestContext context)
     {
         var eventQueue = new AgentEventQueue();
diff --git a/dotnet/tests/Microsoft.Agents.AI.Hosting.A2A.UnitTests/Converters/MessageConverterTests.cs b/dotnet/tests/Microsoft.Agents.AI.Hosting.A2A.UnitTests/Converters/MessageConverterTests.cs
index e26189e9e5..9c7b398644 100644
--- a/dotnet/tests/Microsoft.Agents.AI.Hosting.A2A.UnitTests/Converters/MessageConverterTests.cs
+++ b/dotnet/tests/Microsoft.Agents.AI.Hosting.A2A.UnitTests/Converters/MessageConverterTests.cs
@@ -147,4 +147,67 @@ public void ToParts_WithMultipleMessages_ReturnsAllParts()
         Assert.Equal("First message", result[0].Text);
         Assert.Equal("Second message", result[1].Text);
     }
+
+    [Fact]
+    public void ToParts_AgentResponseUpdate_WithNoContents_ReturnsEmptyList()
+    {
+        // Arrange
+        var update = new AgentResponseUpdate();
+
+        // Act
+        var result = update.ToParts();
+
+        // Assert
+        Assert.NotNull(result);
+        Assert.Empty(result);
+    }
+
+    [Fact]
+    public void ToParts_AgentResponseUpdate_WithTextContent_ReturnsTextPart()
+    {
+        // Arrange
+        var update = new AgentResponseUpdate(ChatRole.Assistant, "Hello from streaming!");
+
+        // Act
+        var result = update.ToParts();
+
+        // Assert
+        Assert.Single(result);
+        Assert.Equal("Hello from streaming!", result[0].Text);
+    }
+
+    [Fact]
+    public void ToParts_AgentResponseUpdate_WithMultipleContents_ReturnsAllParts()
+    {
+        // Arrange
+        var update = new AgentResponseUpdate(ChatRole.Assistant, [
+            new TextContent("First chunk"),
+            new TextContent("Second chunk")
+        ]);
+
+        // Act
+        var result = update.ToParts();
+
+        // Assert
+        Assert.Equal(2, result.Count);
+        Assert.Equal("First chunk", result[0].Text);
+        Assert.Equal("Second chunk", result[1].Text);
+    }
+
+    [Fact]
+    public void ToParts_AgentResponseUpdate_WithUnsupportedContent_FiltersOutNulls()
+    {
+        // Arrange - FunctionCallContent maps to null Part since it's not a supported A2A content type
+        var update = new AgentResponseUpdate(ChatRole.Assistant, [
+            new TextContent("Supported text"),
+            new FunctionCallContent("call-1", "myFunction")
+        ]);
+
+        // Act
+        var result = update.ToParts();
+
+        // Assert - only the text part should be returned
+        Assert.Single(result);
+        Assert.Equal("Supported text", result[0].Text);
+    }
 }