fix: handle APIError code 1000 in _receive_from_model for google-genai >= 1.62.0

[TonyLee-AI]

Problem

google-genai >= 1.62.0 changed live.py to catch ConnectionClosedOK inside _receive() and re-raise it as APIError(code=1000).

Because APIError is not a subclass of ConnectionClosedOK, it bypassed the existing handler in _receive_from_model:

except ConnectionClosedOK:
    pass  # APIError(1000) is NOT caught here

It then propagated to run_live()'s generic except Exception handler, which logged it as an unexpected error — even though WebSocket close code 1000 (RFC 6455 Normal Closure) indicates a clean, intentional session end.

With google-genai == 1.61.0 (which did not perform this conversion), the behaviour was silent and correct.

Fix

Catch APIError in _receive_from_model and treat code 1000 the same as ConnectionClosedOK — silently discard it. Any other APIError code is re-raised unchanged.

except ConnectionClosedOK:
    pass
except genai_errors.APIError as e:
    # google-genai >= 1.62.0 converts ConnectionClosedOK into APIError with
    # WebSocket close code 1000 (RFC 6455 Normal Closure). Treat it the same
    # as ConnectionClosedOK so that a clean session close does not propagate
    # as an unexpected error.
    if e.code != 1000:
        raise

Logs

Before (google-genai==1.68.0, unpatched) — triggered on every normal session close (e.g. call transfer):

ERROR:google_adk.google.adk.flows.llm_flows.base_llm_flow:An unexpected error occurred in live flow: 1000 None.
Traceback (most recent call last):
  File ".../google/genai/live.py", line 535, in _receive
    raw_response = await self._ws.recv(decode=False)
  File ".../websockets/asyncio/connection.py", line 322, in recv
    raise self.protocol.close_exc from self.recv_exc
websockets.exceptions.ConnectionClosedOK: sent 1000 (OK); then received 1000 (OK)
During handling of the above exception, another exception occurred:
  File ".../google/adk/flows/llm_flows/base_llm_flow.py", line 530, in run_live
    async for event in agen:
  ...
  File ".../google/genai/live.py", line 545, in _receive
    errors.APIError.raise_error(code, reason, None)
google.genai.errors.APIError: 1000 None.

After (google-genai==1.68.0, patched) — no error log on normal session close. The session ends silently as intended.

Testing plan

• Added tests/unittests/flows/llm_flows/test_base_llm_flow_connection_close.py with 3 unit tests:
  • test_receive_from_model_connection_closed_ok_is_silent — existing behaviour unchanged
  • test_receive_from_model_api_error_1000_is_silent — new: APIError(1000) is swallowed
  • test_receive_from_model_api_error_non_1000_is_raised — non-1000 codes still propagate
• All 3 tests pass:

PASSED test_receive_from_model_connection_closed_ok_is_silent
PASSED test_receive_from_model_api_error_1000_is_silent
PASSED test_receive_from_model_api_error_non_1000_is_raised
3 passed in 2.35s

• Manual E2E: verified with google-genai==1.68.0 + google-adk==1.27.2 that normal session close (call transfer, hang-up) no longer produces ERROR: An unexpected error occurred in live flow: 1000 None.

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