ConnectionClosedError 1007: Invalid JSON payload (Unknown name "scheduling") when using Gemini Realtime via livekit.plugins.google

[tesla1900]

Bug Description

When using LiveKit Agents with the Google Gemini Realtime plugin, the session consistently crashes with a ConnectionClosedError (1007) due to an invalid JSON payload being sent to the Gemini API.

The Gemini Realtime service rejects the incoming payload, reporting an unknown field "scheduling" inside the tool_response.function_responses[0] object.

2025-11-10 17:05:53,355 - DEBUG livekit.agents - executing tool {"function": "get_application_status", "arguments": "{\"mobileNo\": \"1234\", \"application_no\": \"1234\"}"}
2025-11-10 17:05:56,288 - ERROR livekit.plugins.google - error in receive task:
received 1007 (invalid frame payload data)
Invalid JSON payload received.
Unknown name "scheduling" at 'tool_response.function_responses[0]': Cannot find field.
Traceback (most recent call last):
  File "/home/tesla/work/hdfc_sky/.venv/lib/python3.11/site-packages/livekit/plugins/google/realtime/realtime_api.py", line 779, in _recv_task
    async for response in session.receive():
  File "/home/tesla/work/hdfc_sky/.venv/lib/python3.11/site-packages/google/genai/live.py", line 448, in receive
    while result := await self._receive():
  ...
websockets.exceptions.ConnectionClosedError:
received 1007 (invalid frame payload data)
Invalid JSON payload received.
Unknown name "scheduling" at 'tool_response.function_responses[0]': Cannot find field.

Expected Behavior

The livekit.plugins.google module should send payloads that conform exactly to Gemini’s expected schema. Gemini should not close the connection if LiveKit’s payload structure is valid.

Reproduction Steps

1. Use LiveKit Agents with Google Gemini Realtime plugin.
2. Add any tool (e.g., get_application_status) returning a JSON dict.
3. Start a realtime session and invoke the tool.
4. Observe Gemini disconnects with Invalid JSON payload referring to "scheduling".

Operating System

Fedora Linux 42 (Workstation Edition) / Ubuntu 24.04

Models Used

No response

Package Versions

Python==3.11.13
livekit==1.0.18
livekit-agents==1.2.17
livekit-plugins-google==1.2.17
google-genai==1.49.0
Vertex Model==gemini-live-2.5-flash-preview-native-audio-09-2025

Session/Room/Call IDs

No response

Proposed Solution

Additional Context

No response

Screenshots and Recordings

No response

[longcw]

probably related to #3793, are you using Vertex AI?

[tesla1900]

yes. i can also confirm that this is not an issue on livekit-agent 1.2.9 and google-genai 1.38.0.

[longcw]

@tesla1900 yes the scheduling support was introduced in agents 1.2.12, and it's not supported by Vertex AI. #3793 should fixed the issue, it will be included in next release.

[tesla1900]

@longcw i tested it on 1.2.18 and it is working fine. thanks.