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agent-framework/python/packages/a2a
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Giles Odigwe 289cafcf36 Python: feat(a2a): use non-streaming transport and return_immediately for background ops (#5963)
* feat(a2a): use non-streaming transport and return_immediately for background ops

When stream=False, use a client configured with streaming=False so the
SDK sends a single HTTP POST to message/send instead of opening an SSE
connection via message/stream. This matches the A2A protocol's design:
non-streaming calls use direct request/response, streaming calls use
Server-Sent Events.

Also sets return_immediately=background on SendMessageConfiguration so
the server respects the caller's intent for background operations.

Changes:
- Create separate streaming and non-streaming internal clients (sharing
  the same httpx connection pool) to match protocol transport semantics
- Select non-streaming client for run(stream=False) calls
- Add SendMessageConfiguration with return_immediately=background
- Fallback to streaming client when non-streaming unavailable (e.g. user
  provides their own client via constructor)
- Add tests for client selection and return_immediately behavior

Resolves microsoft/agent-framework#5936

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* fix: address PR review feedback

- Initialize last_request in MockA2AClient.__init__ for explicit state
- Use 'is not None' instead of truthiness for _non_streaming_client check
- Assert return_immediately propagates through non-streaming client path

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* fix: only set configuration when background=True

Only attach SendMessageConfiguration to the request when background=True,
keeping requests minimal and preserving server-side defaults for normal
(foreground) operations. This follows the framework pattern of only
setting optional fields when they have meaningful values.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* fix: only set return_immediately for non-streaming background ops

Per the A2A spec, return_immediately only applies to message/send
(non-streaming). It has no effect on streaming operations. Only set
the configuration field when both background=True and stream=False.

Adds test verifying streaming+background does not set return_immediately.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

---------

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
289cafcf36 ยท 2026-05-21 15:04:56 +00:00
History
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Get Started with Microsoft Agent Framework A2A

Please install this package via pip:

pip install agent-framework-a2a --pre

A2A Agent Integration

The A2A agent integration enables communication with remote A2A-compliant agents using the standardized A2A protocol. This allows your Agent Framework applications to connect to agents running on different platforms, languages, or services.

A2AAgent (Client)

The A2AAgent class is a client that wraps an A2A Client to connect the Agent Framework with external A2A-compliant agents.

from agent_framework.a2a import A2AAgent

# Connect to a remote A2A agent
a2a_agent = A2AAgent(url="http://remote-agent/a2a")
response = await a2a_agent.run("Hello!")

A2AExecutor (Hosting)

The A2AExecutor class bridges local AI agents built with the agent_framework library to the A2A protocol, allowing them to be hosted and accessed by other A2A-compliant clients.

from agent_framework.a2a import A2AExecutor
from a2a.server.apps import A2AStarletteApplication
from a2a.server.request_handlers import DefaultRequestHandler
from a2a.server.tasks import InMemoryTaskStore

# Create an A2A executor for your agent
executor = A2AExecutor(agent=my_agent)

# Set up the request handler and server application
request_handler = DefaultRequestHandler(
    agent_executor=executor,
    task_store=InMemoryTaskStore(),
)

app = A2AStarletteApplication(
    agent_card=my_agent_card,
    http_handler=request_handler,
).build()

Basic Usage Example

See the A2A agent examples which demonstrate:

  • Connecting to remote A2A agents
  • Hosting local agents via A2A protocol
  • Sending messages and receiving responses
  • Handling different content types (text, files, data)
  • Streaming responses and real-time interaction