How I can configure agent to greet connected user ...
# ask-ai
q
How I can configure agent to greet connected user ?
t
Thanks for reaching out, Heorhi. I'm an AI assistant and I'm here to help. Give me a moment while I research this topic.
You're asking how to configure an agent to greet a connected user — here are the ways you can do that and when to use each. 1) Recommended — use the agent lifecycle hook (
on_enter
/
onEnter
) • Override the agent's
on_enter
(Python) or
onEnter
(Node) and call the session reply generator so the agent speaks as soon as it becomes active. • Python example:
Copy code
class Assistant(Agent):
    async def on_enter(self) -> None:
        await self.session.generate_reply(instructions="Greet the user and offer your assistance.")
• Node example:
Copy code
class Assistant extends voice.Agent {
    async onEnter(): Promise<void> {
        this.session.generateReply({ instructions: 'Greet the user and offer your assistance.' });
    }
}
2) Alternative — manually trigger a greeting after session start • If you control session startup, call
session.generate_reply()
immediately after
session.start()
so the agent speaks once the session and room are ready. • Python example:
Copy code
await session.start(room=ctx.room, agent=Assistant())
await session.generate_reply(instructions="Greet the user and offer your assistance.")
• Node example:
Copy code
await session.start({ agent, room: ctx.room });
session.generateReply({ instructions: 'Greet the user and offer your assistance.' });
3) No-code — Agent Builder UI • Enable the Welcome greeting toggle in the Agent Builder and customize the greeting text. • You can include variables like
{{metadata.user_name}}
to personalize the greeting. Notes: • The greeting is synthesized with the agent's configured TTS model. • For telephony, ensure the greeting is sent after the call is answered. Would you like the exact code adapted to your current agent class or room/session setup? Sources: Agents and handoffs | LiveKit docs | Pipeline nodes and hooks | LiveKit docs | Voice AI quickstart | LiveKit docs | Agent Builder | LiveKit docs | Agents telephony integration | LiveKit docs
q
How to prevent user interraptions on greeting message?
t
You're asking how to prevent users from interrupting the agent's greeting — you can disable interruptions on the greeting call. Options: • Use
session.say()
(recommended for static greetings) ◦ Python:
Copy code
await session.say("Hello! Welcome to our service.", allow_interruptions=False)
• Node:
Copy code
await session.say('Hello! Welcome to our service.', { allowInterruptions: false });
• Use
session.generate_reply()
(for LLM-generated/dynamic greetings) ◦ Python:
Copy code
await session.generate_reply(instructions="Say a warm welcome message", allow_interruptions=False)
• Node:
Copy code
session.generateReply({ instructions: 'Say a warm welcome message', allowInterruptions: false });
Notes: • Interruptions are allowed by default; setting
allow_interruptions=False
ensures the greeting plays to completion. • You can still force an interrupt later with
session.interrupt()
if needed. Would you like this added into your existing agent lifecycle (e.g.,
on_enter
) or shown in your session-start flow? Sources: Agent speech and audio | LiveKit docs | Turn detection and interruptions | LiveKit Docs
q
In nodejs I set allowInterruptions to false in two places:
Copy code
agent: new voice.Agent({
  instructions: agentContext,
  tools: toolsService.getAllTools(),
  allowInterruptions: false,
}),
and
Copy code
cas.agentSession.generateReply({ allowInterruptions: false });
both doesn't work. and I can interrupt agent
t
Thanks — I see you're trying to stop users from interrupting the greeting in Node.js and your current changes didn't work. Quick checklist and the fix to make the greeting truly non-interruptible. 1) What to change (required) • Set
allowInterruptions: false
in the AgentSession
voiceOptions
(this is the setting that actually controls interruption detection). • Use
session.say(..., { allowInterruptions: false })
for static greetings (or also pass
allowInterruptions: false
to
generateReply()
), but the session-level
voiceOptions
must be disabled too. Example:
Copy code
const session = new voice.AgentSession({
  /* stt, llm, tts, vad, etc. */
  voiceOptions: {
    allowInterruptions: false,
    preemptiveGeneration: false, // optional: avoid preemptive behavior
  },
});

await session.start({ agent: new voice.Agent({ instructions: agentContext, tools: toolsService.getAllTools() }), room: ctx.room });

await session.say("Hello! I'm here to help you.", { allowInterruptions: false });
2) Why your current code didn't work •
allowInterruptions
in the
new voice.Agent({...})
constructor is ignored and does not control VAD/interrupt behavior. • Per-call flags (on `generateReply`/`say`) do not reliably prevent interruptions if
voiceOptions.allowInterruptions
on the session is true. 3) Quick debugging steps • Confirm
voiceOptions.allowInterruptions
is set to false when creating AgentSession. • Temporarily remove or disable
vad
to see if VAD is forcing endpointing. • Ensure
preemptiveGeneration
is false during greeting. • Verify package version of livekit agents (use >=0.12.0 if possible). If you want, paste the minimal session creation + greeting code you’re running and your livekit-agents version and I’ll point out exactly what to change. Sources: Agents (Node.js) | livekit/livekit_composite | DeepWiki | Turn detection and interruptions | LiveKit Docs | Agent speech and audio | LiveKit docs | Agent session | LiveKit docs
q
How to enable interruptions after first agent message?
t
You want interruptions enabled only after the agent's first message — here's a concise way to do that in Node.js. 1) Send the first greeting with interruptions disabled, wait for playout to finish. 2) For subsequent replies, allow interruptions (default) or explicitly set allowInterruptions: true. Example:
Copy code
const session = new voice.AgentSession({
  /* stt, llm, tts, vad, etc. */
  voiceOptions: {
    // keep default true so later replies are interruptible
    allowInterruptions: true,
    preemptiveGeneration: false,
  },
});

await session.start({ agent: new voice.Agent({ instructions: agentContext, tools: toolsService.getAllTools() }), room: ctx.room });

// 1) non-interruptible greeting
const handle = await session.say("Hello! How can I help you today?", { allowInterruptions: false });
await handle.waitForPlayout(); // ensure greeting finished

// 2) subsequent replies are interruptible
// either generateReply or say() without disabling interruptions:
await session.generateReply({ instructions: "Respond to the user.", allowInterruptions: true });
Notes: • Ensure session-level
voiceOptions.allowInterruptions
is true (default) so the per-call flags behave as expected. • If you globally set
voiceOptions.allowInterruptions: false
, you must explicitly re-enable for later calls. •
waitForPlayout()
ensures the greeting finishes before allowing interruption. Want me to adapt this to your exact session/agent code? Paste the snippet and I’ll tailor it. Sources: Agents (Node.js) | livekit/livekit_composite | DeepWiki | Turn detection and interruptions | LiveKit Docs
q
I disabled interruptions by voiceOptions-allowInterruptions = false in agent session options. Only that helped. So now I need to enable interruptions after first greeting
t
You can re-enable interruptions at runtime by updating the session’s voiceOptions after the greeting finishes. Use
session.updateOptions()
right after the greeting playout completes. Example (Node.js):
Copy code
// session created with voiceOptions.allowInterruptions = false
await session.start({ agent, room: ctx.room });

// non-interruptible greeting
const handle = await session.say("Hello! How can I help you today?", { allowInterruptions: false });
await handle.waitForPlayout(); // ensure greeting finished

// re-enable interruptions for subsequent speech
session.updateOptions({
  voiceOptions: { allowInterruptions: true },
});
Notes: • The update applies to future speech only; it won’t affect the currently playing utterance. • If you used
generateReply()
for the greeting, await its playout the same way before calling
updateOptions()
. • If you want an immediate switch without waiting for playout, skip
waitForPlayout()
but user speech may cut the greeting. Would you like this added into your existing session code? Paste it and I’ll adapt it. Sources: Agents (Node.js) | livekit/livekit_composite | DeepWiki
q
there is no updateOptions method on session
t
Thanks — I’ll correct that and give the accurate options. Because you started the session with
voiceOptions.allowInterruptions = false
, you cannot change that session’s pipeline interruption detection at runtime. The SDK does not support updating
voiceOptions
after start. Your realistic choices are: Option A — Restart the session with interruptions enabled (recommended) 1. Stop/cleanup the current session. 2. Create a new
AgentSession
with
voiceOptions.allowInterruptions = true
. 3. Start the new session and send the greeting as a non-interruptible utterance:
Copy code
// recreate session with interruptions enabled
const session = new voice.AgentSession({
  /* stt, llm, tts, vad, etc. */
  voiceOptions: { allowInterruptions: true, preemptiveGeneration: false },
});
await session.start({ agent, room: ctx.room });

// send greeting non-interruptible for this call only
const handle = await session.say("Hello! How can I help you today?", { allowInterruptions: false });
await handle.waitForPlayout();

// subsequent speech will be interruptible
Option B — If you cannot restart the session: send the greeting in a way that is non-interruptible regardless of session-level setting (may be limited) • If your SDK version supports per-call enforcement when VAD is active, try
session.say(..., { allowInterruptions: false })
and await playout. This may not be reliable when
voiceOptions.allowInterruptions
is false. • Otherwise, implement an application-level guard: ignore/stash incoming user transcripts/events until greeting is complete (e.g., track a
greetingDone
flag and discard or buffer user input until set). Minimal restart steps (Option A): 1. Call any cleanup/stop method on current session (e.g.,
await session.stop()
or close resources). 2. Construct new
AgentSession
with
voiceOptions.allowInterruptions = true
. 3.
await session.start(...)
, send greeting with
{ allowInterruptions: false }
, await playout, then continue. Which option works best depends on your constraints. Please paste: • your current session creation + greeting code, and • your @livekit/agents SDK version (npm list @livekit/agents) — and I’ll give the exact minimal code change to restart the session or implement the app-level guard. Sources: Agents (Node.js) | livekit/livekit_composite | DeepWiki | Turn detection and interruptions | LiveKit Docs | Agent speech and audio | LiveKit docs
q
How to disable and enable then microphone for user in room ?
t
To disable/enable a user's microphone in a LiveKit room, use the client's localParticipant
setMicrophoneEnabled
method. Web / JS / Node (Browser client)
Copy code
// mute
await room.localParticipant.setMicrophoneEnabled(false);

// unmute
await room.localParticipant.setMicrophoneEnabled(true);
Notes: • Disabling unpublishes/mutes the local audio track so other participants stop receiving audio. • Track mute/unmute will emit track events (e.g., TrackMuted/TrackUnmuted) you can listen to update UI. • The same API pattern exists in LiveKit React Native and Flutter clients (syntax varies slightly). If you want, tell me which SDK (web, react-native, flutter) and whether you need to control another participant's microphone from the server side — I can provide exact sample code. Sources: Camera &amp; microphone | LiveKit docs | LiveKit coming to React Native! | Flutter quickstart | LiveKit docs
q
Nodejs sdk doesn't have this api
t
You're right — the Node.js server SDK can't toggle a user's local mic. Two workable options: 1) Mute/unmute server-side (stops audio being forwarded) • Use RoomServiceClient.mutePublishedTrack(room, participantIdentity, trackSid, true/false). • Get track SIDs from roomService.listParticipants(roomName). 2) Disable the client mic (best for truly turning off user's device) • Server sends a data message or websocket command to the client. • Client receives it and calls
room.localParticipant.setMicrophoneEnabled(false)
/
true
. If you tell me whether you control the client code (web, React Native, Flutter) and whether you prefer server-side mute or client-side control, I’ll provide the exact code snippets for your stack. Sources: Managing participants | LiveKit docs | Server-side | livekit/livekit_composite | DeepWiki | Camera &amp; microphone | LiveKit docs
q
Client is SIP provider
t
With a SIP client you cannot call client-side APIs like
setMicrophoneEnabled
. Two practical approaches remain — pick based on what control you have over the SIP endpoint: 1) Server-side mute (recommended when you can't control SIP device) • Use the LiveKit server SDK to mute the participant's published audio track. This prevents other room participants from hearing them but does not disable the SIP device's mic. • Steps: ◦ Find the participant's audio track SID (via
roomService.listParticipants(roomName)
). ◦ Call
roomService.mutePublishedTrack(roomName, participantIdentity, trackSid, true)
to mute and
... , false)
to unmute. Example (Node.js):
Copy code
import { RoomServiceClient } from 'livekit-server-sdk';

const svc = new RoomServiceClient(lkUrl, apiKey, apiSecret);

// list participants to find audio track SID
const participants = await svc.listParticipants('room-name');
const p = participants.find(x => x.identity === 'participant-identity');
const audioTrack = p.tracks.find(t => t.type === 'audio');

await svc.mutePublishedTrack('room-name', p.identity, audioTrack.sid, true); // mute
await svc.mutePublishedTrack('room-name', p.identity, audioTrack.sid, false); // unmute
2) SIP-side mute (recommended if you control SIP provider/config) • Send a SIP signal (e.g., SIP INFO, RE-INVITE with SDP to remove sendrecv, or use provider API) to instruct the SIP endpoint to stop sending audio. This fully disables the microphone on the SIP side. • After greeting, send the SIP unmute command to allow audio again. 3) Hybrid / UX-safe approach when exact mute semantics matter • Use server-side mute to prevent audio reaching other participants while also sending a SIP mute command if you can, ensuring both server and endpoint are muted. • Or send a data/event to any client-side controller you have so it mutes locally. Which fits you? • If you control the SIP stack, I can show a SIP re-INVITE or INFO example to mute/unmute. • If you do not control SIP endpoints, use the RoomServiceClient mutePublishedTrack approach — tell me how you identify participants (identity vs SID) and I’ll tailor the snippet.