Async Audio Twilio

Twilio wrapper for @silyze/async-audio-stream

Install

npm install @silyze/async-audio-twilio

Usage

Import and use it in your project:

import TwilioStream from "@silyze/async-audio-twilio";

// Use with a WebSocket connection from Twilio Media Streams
const stream = await TwilioStream.from(ws);

// Wait for stream to be ready (after "start" event)
await stream.ready;

// Read audio (u-law format)
for await (const chunk of stream.read()) {
  // process chunk (Buffer)
}

// Write audio (must be u-law encoded)
await stream.write(ulawBuffer);

// Listen for DTMF tones
for await (const digit of stream.dtmf.read()) {
  console.log("DTMF:", digit);
}

// Access Twilio metadata
const startEvent = await stream.startEvent;
console.log("Call SID:", startEvent.start.callSid);

const stopEvent = await stream.stopEvent;
console.log("Call ended for SID:", stopEvent.stop.callSid);

API

TwilioStream.from(websocket: WebSocket): Promise<TwilioStream>

Wraps a Twilio Media Stream WebSocket into an AudioStream interface.

stream.read(signal?: AbortSignal): AsyncIterable<Buffer>

Yields u-law audio buffers from the Twilio media stream.

stream.write(input: Buffer): Promise<void>

Sends u-law audio buffer into the WebSocket stream.

stream.dtmf: AsyncReadStream<string>

Yields detected DTMF digits (as strings).

stream.startEvent: Promise<TwilioStartEvent>

Resolves to the Twilio start event, containing metadata such as callSid, streamSid, and customParameters.

stream.stopEvent: Promise<TwilioStopEvent>

Resolves to the Twilio stop event.

stream.ready: Promise<void>

Resolves when the start event is received — useful for waiting before sending/receiving audio.

stream.format: AudioFormat

Returns ULawFormat(8000) — used by Twilio Media Streams.