aloof-forest-57428
12/23/2025, 4:54 AMtall-airline-16756
12/23/2025, 4:54 AMtall-airline-16756
12/23/2025, 4:55 AMagent_name in room config) and that dispatch completes before connecting the client.
• Connection / lifecycle ordering: Verify you call ctx.connect() / start the RoomIO (e.g., await room_io.start()) before publishing or expecting audio. Delayed or out-of-order connects can drop the first utterance.
• Preconnect buffering: If users speak before the agent is fully connected, early audio can be lost. Enable preconnect audio buffering on the client to capture initial speech.
• Reused state or room name: Reusing the same room or session objects across calls can cause leftover tracks or routing conflicts. Try unique room names per call and ensure session/room cleanup.
• Missing audio tracks: Confirm audio tracks are published/subscribed correctly on each attempt (no errors when starting audio).
To pinpoint the issue I need a few details
• Are you on LiveKit Cloud? If so, which plan (Build/free vs paid)?
• How are you dispatching the agent — automatic or explicit (show the dispatch snippet or token config if possible)?
• Relevant code snippets around the agent entrypoint: where you create/start the session, call ctx.connect(), and start room_io.
• Logs from the first three attempts (agent startup logs, dispatch logs, and any errors).
• Whether the client uses preconnect buffering and whether you reuse room names.
If you share those, I’ll suggest exact fixes and code changes.
Sources: Quotas and limits | LiveKit docs | Agent dispatch | LiveKit docs | Authentication | LiveKit docs | examples/bank-ivr | livekit/livekit_composite | DeepWiki | Job lifecycle | LiveKit docsaloof-forest-57428
12/23/2025, 4:57 AMtall-airline-16756
12/23/2025, 4:58 AMcreate_dispatch.
Short checklist of highest-probability causes (based on your code)
• Race between dispatch and caller join: you dispatch immediately; agent may start before the SIP caller is present, so it sees no participant/audio and exits or never links.
• Worker/process lifecycle (DB connect): DB connect per worker must be reliable — if a worker blocks or fails to connect, the agent job can hang or die.
• Connection sequencing / double connect: calling await ctx.connect() then session.start(...) can create race/duplication — session.start will handle connecting and subscriptions.
• No explicit participant binding: if the agent joins before caller or room state hasn’t propagated, RoomIO may not auto-link to the SIP participant → no audio.
• Premature room deletion: deleting the room on a perceived agent-failure can create inconsistent state for retries.
Immediate, minimal changes to try (in order)
1. Delay dispatch until the caller is confirmed joined.
◦ Poll the room participants (via LiveKit API) and only call create_dispatch after you detect the SIP participant.
1. Remove the extra await ctx.connect() and rely on await session.start(...) to establish the agent connection.
2. Explicitly bind the agent to the caller participant when starting the session:
◦ Extract the SIP participant identity from ctx.room.participants and pass it in RoomInputOptions (e.g., participant_identity or explicit participant_kinds).
1. Make DB connect idempotent and per-worker safe:
◦ Ensure each worker calls db_manager.connect() and waits until db_manager.connected before proceeding; add short retries.
1. Stop deleting the room immediately on a failed agent join. Wait for an explicit session end or a longer timeout before cleanup.
2. Add short stabilization delays where needed:
◦ After confirming caller joined, wait ~0.5–1.0s before dispatching/starting session to let SFU state propagate.
1. Enable client preconnect audio buffering (on the caller side) so early speech isn’t lost.
Key logging/events to add (will make root cause obvious)
• Log participant join events, track publications, and when the agent publishes/subscribes.
• Log lifecycle steps: "caller detected", "dispatch requested", "agent process started", "session.start called", "agent linked to participant".
• If agent exits, log exit reason/traceback and whether RoomIO had any linked participant.
If you want, I can:
• Provide the small code patches for (A) polling/wait-for-caller before dispatch, (B) removing ctx.connect() and explicitly binding participant in RoomInputOptions, and (C) a safe ensure_db_connected() helper. Which one should I give first?aloof-forest-57428
12/23/2025, 5:01 AMcreate_dispatch after you detect the SIP participant.
2. Remove the extra await ctx.connect() and rely on await session.start(...) to establish the agent connection.
3. Explicitly bind the agent to the caller participant when starting the session:
◦ Extract the SIP participant identity from ctx.room.participants and pass it in RoomInputOptions (e.g., participant_identity or explicit participant_kinds).
4. Make DB connect idempotent and per-worker safe:
◦ Ensure each worker calls db_manager.connect() and waits until db_manager.connected before proceeding; add short retries.
5. Stop deleting the room immediately on a failed agent join. Wait for an explicit session end or a longer timeout before cleanup.
6. Add short stabilization delays where needed:
◦ After confirming caller joined, wait ~0.5–1.0s before dispatching/starting session to let SFU state propagate.
7. Enable client preconnect
the things u have mentiond what if agent never joins the room and the sip participant is still waitinh inside the room wouldnt that cuse an issue since its a cal ?tall-airline-16756
12/23/2025, 5:02 AMaloof-forest-57428
12/23/2025, 5:05 AMtall-airline-16756
12/23/2025, 5:05 AMaloof-forest-57428
12/23/2025, 5:10 AMtall-airline-16756
12/23/2025, 5:10 AMcreate_dispatch.
5. Wait for the agent participant to join (timeout + retries).
6. Start the AgentSession and explicitly bind to the SIP participant identity.
7. Monitor session and participant events; on failures use a fallback (IVR/human/voicemail) after retries.
8. Clean up only after session end or fallback complete (don’t delete room immediately on first failure).
Config choices (recommended)
• Caller-wait timeout: 10s
• Agent-join timeout: 10s per attempt
• Dispatch retries: 1–2
• Stabilization delay: 0.5–1.0s
• Overall caller cooldown before final cleanup: 30–60s
Code snippets (Python-ish pseudocode; adapt to your codebase)
1) Helper: poll for caller (SIP participant)
async def wait_for_sip_caller(lk_url, api_key, api_secret, room_name, timeout=10.0, poll_interval=1.0):
api = api.LiveKitAPI(lk_url, api_key, api_secret)
deadline = asyncio.get_event_loop().time() + timeout
try:
while asyncio.get_event_loop().time() < deadline:
room_info = await api.room.get_room(api.RoomRequest(room=room_name))
for p in room_info.participants:
# ParticipantKind enum may differ by SDK; check SDK value for SIP
if p.kind == rtc.ParticipantKind.PARTICIPANT_KIND_SIP:
return p.identity
await asyncio.sleep(poll_interval)
finally:
await api.aclose()
return None
2) Dispatch agent with retries and wait for agent join
async def dispatch_agent_and_wait(lk_url, api_key, api_secret, room_name, agent_name,
metadata, max_retries=2, join_timeout=10.0):
dispatch_api = api.LiveKitAPI(lk_url, api_key, api_secret)
try:
for attempt in range(1, max_retries + 1):
await dispatch_api.agent_dispatch.create_dispatch(
api.CreateAgentDispatchRequest(room=room_name, agent_name=agent_name, metadata=metadata)
)
# wait for agent participant
joined = await wait_for_agent_participant(dispatch_api, room_name, agent_name, timeout=join_timeout)
if joined:
return True
# backoff before retry
await asyncio.sleep(1.0 * attempt)
return False
finally:
await dispatch_api.aclose()
async def wait_for_agent_participant(api_client, room_name, agent_name, timeout=10.0, poll_interval=0.5):
deadline = asyncio.get_event_loop().time() + timeout
while asyncio.get_event_loop().time() < deadline:
try:
room_info = await api_client.room.get_room(api.RoomRequest(room=room_name))
for p in room_info.participants:
if p.identity == agent_name:
return True
except Exception:
pass
await asyncio.sleep(poll_interval)
return False
3) Start agent session binding to caller participant
# In your agent worker entrypoint (ctx available)
# 1. Ensure db connected per-worker (ensure_db_connected helper)
# 2. Do NOT call await ctx.connect() separately if session.start handles it.
# find SIP participant identity from ctx.room.participants
caller_identity = None
for pid, participant in ctx.room.participants.items():
if participant.kind == rtc.ParticipantKind.PARTICIPANT_KIND_SIP:
caller_identity = participant.identity
break
if not caller_identity:
logger.error("No SIP caller found in room at agent start")
# optionally retry a short time, then exit
# small stabilization delay
await asyncio.sleep(0.5)
# build session and pass explicit participant binding
session = AgentSession(...)
await session.start(
agent=agent,
room=ctx.room,
room_input_options=RoomInputOptions(
audio_enabled=True,
participant_kinds=[rtc.ParticipantKind.PARTICIPANT_KIND_SIP],
participant_identity=caller_identity, # explicit binding
),
room_output_options=RoomOutputOptions(audio_enabled=True),
)
4) Wait-with-timeout / fallback flow (caller-facing safety)
# Orchestrator flow when initiating the call:
caller_identity = await wait_for_sip_caller(...)
if not caller_identity:
# Caller never joined: run fallback (hangup or voicemail) immediately
run_fallback("caller_not_joined")
return
# short stabilization
await asyncio.sleep(0.8)
# dispatch and wait for agent
agent_joined = await dispatch_agent_and_wait(..., max_retries=2, join_timeout=10.0)
if not agent_joined:
# Agent never joined: attempt fallback (IVR, human transfer, voicemail)
run_fallback("agent_unavailable")
# keep room alive for cooldown then cleanup (30s)
await asyncio.sleep(30.0)
await lk_api.room.delete_room(api.DeleteRoomRequest(room=room_name))
return
# Agent joined => proceed (agent worker will start session and handle call)
5) DB connect helper for worker processes
async def ensure_db_connected(db_manager, max_wait=5.0):
start = asyncio.get_event_loop().time()
if not db_manager.connected:
await db_manager.connect()
while not db_manager.connected and (asyncio.get_event_loop().time() - start) < max_wait:
await asyncio.sleep(0.1)
return db_manager.connected
6) Logging & events to add (minimal)
• Log when caller detected, when dispatch requested, when agent process starts, when agent joins, when tracks are published, and when session ends.
• Add event handlers for participant connected/disconnected and track_published to trace audio routing.
7) Cleanup rules (safe)
• Never delete room immediately on first agent join failure.
• After final fallback/policy decision, end call politely (play IVR message or transfer), wait short cooldown, then delete room.
Final notes
• The key fixes: wait for caller before dispatch, bind agent explicitly to the SIP participant when starting the session, and implement timeouts/retries/fallbacks.
• Adjust timeouts based on observed agent cold-starts on your EC2 instance — if you see longer startup times, increase agent-join timeout.
If you want, I can:
• Convert these snippets into a ready-to-drop patch for your exact files (entrypoint + dispatch caller), or
• Provide a single combined orchestrator function that implements the full flow end-to-end.
Which would you prefer?