Control only (no audio)

Set mediaFactory: null explicitly; omitting it selects browser media. Also set autoAnswer: false so outbound offers don't trigger attempts to answer without media. This works in browsers and Node 20+.

The following fragment assumes serverUrl, token, and your render callback:

import { BabelconnectClient } from "@babelforce/babelconnect-sdk";

const bc = BabelconnectClient.connect({
  serverUrl, token, mediaFactory: null, autoAnswer: false,
  onError: e => console.error(e.code, e.message),
});
const stop = bc.subscribe(render);
bc.sendSms("+15551234567", "On my way!");
// When finished: stop(); await bc.close();

When to use it

Use this mode for an agent's dashboard, messaging, presence, or automation. A token identifies one agent; this is not a team-wide observer API. Go automation has a different default: a silent WebRTC leg.

What works without audio

The state stream, non-media intents and unary fetches still work. answerCall needs media and reports no_media when none is configured. A placeCall intent can succeed, but a human still needs somewhere to hear the call.

Registration changes routing. register() loads presence options, caller IDs, contacts and feature config and requests WebRTC reachability, even with an empty capabilities list or no media factory. For calls on an external phone, register, wait for the resulting deployment data, then set setWebrtc(false) and setAgentNumber(number). Confirm both values in state before dialing. TypeScript sends are asynchronous; adjacent calls do not guarantee completion order. Repeat the routing setup after registering a replacement session.

For a pure observer, avoid registration unless those reference data are needed; registration is not a passive read. If you do register, restore the intended audio route. With WebRTC off and no external number, the agent is unreachable.

See where calls ring, client cleanup, and error handling.