다음의 에러의 원인은 뭐야? failed to publish transcription\nTraceback (most recent call last):\n File \"/app/.venv/lib/python3.12/site-packages/livekit/agents/voice/room_io/_output.py\", line 427, in capture_text\n self._writer = await self._create_text_writer()\n ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\n File \"/app/.venv/lib/python3.12/site-packages/livekit/agents/voice/room_io/_output.py\", line 403, in _create_text_writer\n return await self._room.local_participant.stream_text(\n ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\n File \"/app/.venv/lib/python3.12/site-packages/livekit/rtc/participant.py\", line 578, in stream_text\n await writer._send_header()\n File \"/app/.venv/lib/python3.12/site-packages/livekit/rtc/data_stream.py\", line 189, in _send_header\n raise ConnectionError(cb.send_stream_header.error)\nConnectionError: engine: connection error: engine is closed

Thanks for reaching out, Dan(송희웅). I'm an AI assistant and I'm here to help. Give me a moment while I research this topic.

Participant disconnected -> process exiting -> Error(failed to publish transcription\nTraceback (most recent call last):\n File \"/app/.venv/lib/python3.12/site-packages/livekit/agents/voice/room_io/_output.py\", line 298, in _publish_transcription\n await self._room.local_participant.publish_transcription(transcription)\n File \"/app/.venv/lib/python3.12/site-packages/livekit/rtc/participant.py\", line 285, in publish_transcription\n raise PublishTranscriptionError(cb.publish_transcription.error)\nlivekit.rtc.participant.PublishTranscriptionError: engine: connection error: engine is closed)

I'm sorry to hear you're encountering the "PublishTranscriptionError: engine is closed" message. This usually happens when there's an attempt to publish transcription data after the RTC engine has already been closed or disconnected. It might occur if a participant has disconnected, a reconnection didn't go through, or if the engine was shut down during cleanup. To help prevent this, it's a good idea to check that the room and engine are still connected before calling

publish_transcription

. You can listen for disconnection events and programmatically verify the connection status. Also, wrapping your

publish_transcription

call in a try-catch block can help handle any errors smoothly. If you see this error after trying to reconnect, you might need to re-establish the engine connection before trying again. Please feel free to reach out if you'd like me to walk you through your specific setup or if you have any other questions—I’m here to help! Sources: livekit-rtc/livekit/rtc/participant.py | livekit-ffi/src/livekit.proto.rs | lib/src/core/engine.dart

다음과 같이 참여자가

participant_disconnected

되었을때

shutdown

을 하는데. 이렇게 하면 안되는거야?

python
...

job_ctx = get_job_context()
room = job_ctx.room

@room.on("participant_disconnected")
def _on_participant_disconnected(event: rtc.RemoteParticipant):
    job_ctx.shutdown()

`

I understand that calling

shutdown

directly in the

participant_disconnected

event handler might seem like a straightforward solution, but it’s usually best to avoid this unless your application specifically needs it. This event fires whenever any participant leaves the room, and shutting down right away could end the session too soon, even if others are still connected. Here are some friendly tips to help you manage this smoothly: • Before shutting down, check if the room is actually empty by verifying

len(ctx.room.remote_participants) == 0

. • Use

ctx.shutdown(reason="...")

to gracefully disconnect the agent when the time is right. • If you want more detailed control, consider setting

RoomInputOptions.close_on_disconnect=False

so you can manage the session lifetime yourself. Following these suggestions will help ensure the agent only shuts down when everyone has left or when the right conditions are met. If you’d like, I’m here to help clarify anything or assist with your implementation—just let me know! Sources: Inside a session | LiveKit Docs | livekit-rtc/livekit/rtc/room.py | livekit-agents/livekit/agents/job.py

그렇다면 참가자가 participant_disconnected 나갔을때 Agent Session을 종료하려면?

I'm here to help you properly terminate an agent session when a participant disconnects. Here are some friendly approaches you can consider: • Automatic Termination: LiveKit thoughtfully closes the agent session automatically when the linked participant disconnects under certain conditions (like

CLIENT_INITIATED

,

ROOM_DELETED

, or

USER_REJECTED

). This happens thanks to the

close_on_disconnect

option, which is turned on by default to make things easier for you. • Manual Termination: If you prefer more control, you can gently close the agent session by calling

ctx.shutdown(reason="Session ended")

. Another way is to use

session.aclose()

to end the session whenever you need. • Full Room Termination: And if your goal is to end the whole room session and disconnect everyone, the server API

deleteRoom

is the way to go. Also, it’s a great idea to handle the

close

event on the session for any cleanup tasks you might want to do, like logging or removing the room. If you'd like, I’m more than happy to walk you through more details or share examples to make your implementation smoother. Just let me know! Sources: agents/src/voice/room_io/room_io.ts | Job lifecycle | LiveKit Docs | Inside a session | LiveKit Docs | livekit-agents/livekit/agents/voice/agent_session.py

다음과 같이

_on_participant_disconnected

함수에 async 를 사용할수 있어? 사용할수 없는것 같은데? ```python @room.on("participant_disconnected") async def _on_participant_disconnected(event: rtc.RemoteParticipant): logger.bind( event="SESSION_PARTICIPANT", stage="disconnected", room=room.name, participant=getattr(event, "identity", None), ).info("Participant disconnected") session.history.add_message( role="developer", content="[END CALL BY USER]", ) await session.aclose()

Thanks for reaching out! I wanted to share a little tip about the

participant_disconnected

event handler in the LiveKit Python SDK. It can’t be declared as an

async

function using

async def

because the SDK doesn’t support directly awaiting asynchronous code inside this handler. But don’t worry! You can define the handler as a regular synchronous function (

def

) and then use

asyncio.create_task()

to run your asynchronous operations in the background. Here’s a simple example:

def on_participant_disconnected(participant: rtc.RemoteParticipant):
    if (session := self._sessions.pop(participant.identity)) is None:
        return
    # Start the async session closure as a background task
    task = asyncio.create_task(self._close_session(session))
    self._tasks.add(task)  # Keep a reference to the task
    task.add_done_callback(lambda _: self._tasks.discard(task))

This way, the event loop keeps running smoothly, and you can still handle your async work. If anything’s unclear or you’d like me to walk you through more examples, just let me know—I’m here to help! Sources: examples/voice_agents/realtime_joke_teller.py | livekit-rtc/livekit/rtc/participant.py | agent/game_host.py