To implement a push-to-talk feature with an AI agent in your Flutter frontend, you can use manual turn control on the backend and RPC calls to manage when the agent listens and responds. Here’s how you can achieve this: Backend Setup: 1. Configure the AI agent with manual turn detection to disable automatic speech detection:

session = AgentSession(
    turn_detection="manual",
    # ... stt, tts, llm, etc.
)

# Disable audio input at the start
session.input.set_audio_enabled(False)

1. Implement RPC methods to control the push-to-talk functionality: • Start Turn (Button Press):

@ctx.room.local_participant.register_rpc_method("start_turn")
async def start_turn(data: rtc.RpcInvocationData):
    session.interrupt()
    session.clear_user_turn()
    room_io.set_participant(data.caller_identity)
    session.input.set_audio_enabled(True)

• End Turn (Button Release):

@ctx.room.local_participant.register_rpc_method("end_turn")
async def end_turn(data: rtc.RpcInvocationData):
    session.input.set_audio_enabled(False)
    session.commit_user_turn(transcript_timeout=10.0)

• Cancel Turn:

@ctx.room.local_participant.register_rpc_method("cancel_turn")
async def cancel_turn(data: rtc.RpcInvocationData):
    session.input.set_audio_enabled(False)
    session.clear_user_turn()

Frontend Integration: 1. In your Flutter app, implement a button that: ◦ Calls the

start_turn

RPC method on press. ◦ Calls the

end_turn

RPC method on release. ◦ Optionally calls

cancel_turn

if the user cancels mid-speech. 1. Ensure the backend communicates to the frontend that push-to-talk is supported:

async def handle_request(request: JobRequest) -> None:
    await request.accept(
        identity="ptt-agent",
        attributes={"push-to-talk": "1"},
    )

Additional Notes: • The

session.commit_user_turn()

method ensures the AI agent responds only after the button is released. • You can implement custom logic to handle empty user turns and prevent the agent from generating a reply when no speech is detected. If you need further details on integrating the RPC calls into your Flutter app, let me know! Sources: Turn detection and interruptions | LiveKit Docs | README.md | LiveKit Docs