.NET : Support for A2A streaming in `MapA2A`

[anktsrkr]

While integrating A2A with the Agent Framework, I noticed that the MapA2A extension currently uses RunAsync, which produces a fully-buffered response rather than streaming partial deltas.

Reference:

agent-framework/dotnet/src/Microsoft.Agents.AI.Hosting.A2A/AIAgentExtensions.cs

Line 50 in 73761aa

var response = await hostAgent.RunAsync(

Since A2A supports streaming, I’m trying to understand the recommended way to enable streaming through this helper.

Questions:

• Is there an existing streaming API (e.g., RunStreamingAsync) that MapA2A is expected to use?
• If not, is streaming support planned for MapA2A based on Agent's capability?

[anktsrkr]

Also I noticed that the .ToPart() method in currently handles TextContent, UriContent, and DataContent, but drops FunctionCallContent entirely.

Reference:

agent-framework/dotnet/src/Microsoft.Agents.AI.Hosting.A2A/AIAgentExtensions.cs

Line 57 in 73761aa

var parts = response.Messages.ToParts();

This causes structured function calls from the model to be lost when converting to A2A parts, which breaks tool invocation workflows.

Questions:

• Is there a recommended way to preserve FunctionCallContent in .ToPart()?

Thanks for the guidance!

[DeagleGross]

Currrently being supported via Task support in A2A at #3732

[markwallace-microsoft]

@anktsrkr, friendly reminder — this issue is waiting on your response. Please share any updates when you get a chance. (This is an automated message.)

[filipw]

The A2A integration still only uses agent.RunAsync not agent.RunStreamingAsync. The linked PR adds ContinuationToken/background-task support, which is a different feature from real-time token streaming.

To support token streaming to the caller, we still have to polyfill this feature by adding something like taskManager.OnTaskUpdated += RunAgentStreamingAsync;. This should be a first class extension in AF (for example MapStreamingA2A)

[ecc-parity-check]

Is there any sample code showing how to use Tasks to get messages with streaming with A2A?
Something like a simple use case - Agent returns tokens from LLM and I want to forward those tokens out via A2A.
The provided "sample" in the PR:

        taskManager.OnMessageReceived += OnMessageReceivedAsync;
        taskManager.OnTaskUpdated += OnTaskUpdatedAsync;
        taskManager.OnTaskCancelled += OnTaskCancelledAsync;

doesn't tell me much, what is a taskManager, who should create it, and where (client, server), what the handlers should do?