Great job — your code works and shows deep understanding of streaming, chunk parsing, and A2A context handling.
To simplify and align with the official A2A client patterns (like test_client.py), focus on these refinements:
- Move all A2A-specific logic into a helper module (
a2a_adapter.py). - Keep your LangGraph node (
call_a2a_server) lightweight — just call the adapter and update state. - This mirrors the clean layering in the example client.
- Use the built-in Pydantic models (e.g.,
chunk.root.result.artifact.parts) instead of generic.get()chains. - Avoid converting everything to dicts; rely on
model_dump()only for debugging or logging. - The SDK already normalizes streaming and non-streaming responses for you.
-
Follow the example’s pattern:
async for chunk in client.send_message_streaming(request): data = chunk.model_dump(mode='json', exclude_none=True) result = data.get('result') or data.get('root', {}).get('result', {})
-
Extract text from
artifact.parts[].textand stop — skip multi-path heuristics or “longest-chunk” logic for now.
-
Factor your message creation into a helper:
def build_message_params(text, task_id=None, context_id=None) -> MessageSendParams: ...
-
Keeps your node cleaner and matches the
test_client.pystructure.
- The non-streaming fallback inside
call_a2a_server()isn’t needed for your current setup. - Keep it in a separate function or remove it unless you’re testing fault tolerance.
| Area | Current | Align With |
|---|---|---|
| A2A logic | Inlined in graph node | Reusable adapter (get_a2a_answer) |
| Response handling | Manual JSON parsing | Typed SDK models |
| Message payloads | Built inline | Helper function |
| Graph role | Does everything | Just orchestrates nodes |
| Fallbacks | Inline | Optional helper |
Outcome: Your code becomes 40–50% smaller, easier to maintain, and fully aligned with how most of the A2A user community structures LangGraph clients today.