Docs - AI phone agents for SMB

@telzino/voice is the framework-independent browser client.

npm i @telzino/voice

`new TelzinoVoice(config)`

import { TelzinoVoice } from '@telzino/voice';

const voice = new TelzinoVoice({ publishableKey: 'pk_live_...' });

Member	Type	Description
`config.publishableKey`	`string`	Publishable key (`pk_...`). Safe in the browser, but only works from allowed origins.
`config.session`	`(req: SessionRequest) => Promise<SessionResponse>`	Custom session provider, used instead of the key. See Authentication.
`config.apiBaseUrl`	`string`	Defaults to `https://api.telzino.com`. During the beta, use `https://beta.telzino.io`.
`activeCall`	`VoiceCall \| null`	The call in progress, if any.
`start(opts)`	`(opts: StartOptions) => Promise<VoiceCall>`	`opts` is `{ agentId, participantName?, metadata? }`. Rejects with `invalid_request` if a call is already active.
`listInputDevices()`	`() => Promise<Array<{ deviceId: string; label: string }>>`	Available microphones. Labels are empty until mic permission is granted.

Provide either publishableKey or session. With neither, start() rejects with invalid_request.

`start(opts, hooks?)`

const call = await voice.start({
  agentId: '3f1c2a4e-8b7d-4c3a-9e2f-1a2b3c4d5e6f',
  participantName: 'Ada',
  metadata: { plan: 'pro' },
});

Option	Type	Description
`agentId`	`string`	The id (UUID) of the agent to call.
`participantName`	`string`	Display name of the caller. Up to 80 characters. Defaults to “Guest”.
`metadata`	`Record<string, string>`	String values only, up to 4096 bytes as JSON. Background data about the caller, not instructions. See Security.

start() asks for microphone permission, so call it from a user gesture such as a button click. The optional second argument hooks is { onCall?: (call: VoiceCall) => void }. onCall fires synchronously once the call object exists, before it emits connecting. Use it to subscribe to events from the start, or to call end() while the call is still connecting.

`VoiceCall`

start() resolves to a VoiceCall once the connection is up.

Member	Type	Description
`sessionId`	`string`	Server session id.
`agent`	`{ id: string; name: string }`	The agent being called.
`status`	`CallStatus`	`idle`, `connecting`, `connected`, `reconnecting` or `ended`.
`agentState`	`AgentState`	`initializing`, `listening`, `thinking`, `speaking` or `unknown`.
`transcript`	`TranscriptItem[]`	Live transcript, `{ id, role, text, final, timestamp }`.
`messages`	`ChatMessage[]`	Text chat messages, `{ id, role, text, timestamp }`.
`muted`	`boolean`	Whether the microphone is muted.
`needsUserGesture`	`boolean`	True when the browser blocked audio playback; call `resumeAudio()` from a click.
`on(event, fn)`	`(event, fn) => () => void`	Subscribe; returns an unsubscribe function. See Events and errors.
`setMuted(muted)`	`Promise<void>`	Mute or unmute the microphone.
`sendText(text)`	`Promise<void>`	Send a text chat message to the agent.
`setInputDevice(deviceId)`	`Promise<void>`	Switch microphone.
`resumeAudio()`	`Promise<void>`	Start audio playback after a user gesture.
`end()`	`Promise<void>`	Hang up. Safe to call more than once.

call.on('transcript', (item) => console.log(item.role, item.text, item.final));
call.on('agentState', (state) => console.log('agent is', state));
call.on('ended', ({ reason }) => console.log('call ended:', reason));

await call.setMuted(true);
await call.setMuted(false);

await call.end();

A transcript item can be updated several times while a line is spoken. final is false for partial text and true once the line is complete. Items keep the same id across updates.

Audio playback

Browsers can block audio until the user interacts with the page. When that happens, needsUserGesture becomes true and a needsUserGesture event fires. Show a button and call resumeAudio() from its click handler.

Choosing a microphone

const devices = await voice.listInputDevices();
await call.setInputDevice(devices[0].deviceId);

Device labels are empty until the user grants microphone permission.

Setup Guides

Managing AI agents

Telzino Dashboard

Connect App

Agent Settings

Agent Functions

NetSapiens Functions

Event Webhooks

Agent Examples

Integrations

SDK

White Label

Configure agents with AI

Developers

Core API

`new TelzinoVoice(config)`

`start(opts, hooks?)`

`VoiceCall`

Audio playback

Choosing a microphone