This package has been deprecated

Author message:

Effective April 1, 2025, Twilio will end of life (EOL) our support for Twilio Voice JS SDK version 1.x. Please migrate to version 2.x

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1.15.1 • Public • Published

Deprecation Notice

This repository does not contain the latest version of Twilio's Javascript Voice SDK. Although this major version will continue to be supported, it will no longer receive new features. We recommend that all users upgrade to 2.0 at their earliest convenience, in order to receive access to new features as they arrive.

Twilio's JavaScript Voice SDK 2.0 is now GA!

This repository contains an outdated version of Twilio's Javascript Client SDK. We have now released 2.0 as Generally Available. You can find the new repository containing the JavaScript Voice SDK 2.0 here.

This new major version cleans up a lot of the legacy API, such as:

  • Removing deprecated methods
  • Renaming classes and methods to be less ambiguous
  • Implementing the new features from 1.x as defaults rather than behind feature flags
  • Completely moving to the new TwilioError class which is standardized between Voice SDKs and contains much more detailed information about errors

Additionally, new features from this point onward will only be added to the 2.0 project, and not be backported to 1.x, so anyone looking to use the latest features will want to be moved to the new 2.0 API.

Existing customers can review our migration guide here.


NPM CircleCI

twilio-client.js allows you to add real-time voice and PSTN calling to your web apps.

Issues and Support

Please check out our common issues page or file any issues you find here on Github. For general inquiries related to the Voice SDK you can file a support ticket. Please ensure that you are not sharing any Personally Identifiable Information(PII) or sensitive account information (API keys, credentials, etc.) when reporting an issue.



We recommend using npm to add the Client SDK as a dependency.

npm install twilio-client --save

Using this method, you can import twilio-client.js using ES Module or TypeScript syntax:

import { Device } from 'twilio-client';

Or using CommonJS:

const Device = require('twilio-client').Device;


Though not recommended, releases of twilio-client.js are also hosted on a CDN and you can include these directly in your web app using a <script> tag.

<script src=""></script>

Using this method, twilio-client.js will set a browser global:

const Device = Twilio.Device;


Running unit tests requires no setup aside from installation (above). You can run unit tests via:

npm run test:unit

Integration tests require some set up:

  1. If the account you want to use doesn't already have a TwiML app set up, create one using the TwiML code below.
  2. Copy config.example.yaml to config.yaml, replacing the placeholder information with valid credentials.
<?xml version="1.0" encoding="UTF-8"?>
      <Parameter name="duplicate" value="12345" />
      <Parameter name="duplicate" value="123456" />
      <Parameter name="custom + param" value="我不吃蛋" />
      <Parameter name="foobar" value="some + value" />
      <Parameter name="custom1" value="{{Custom1}}" />
      <Parameter name="custom2" value="{{Custom2}}" />
      <Parameter name="custom3" value="{{Custom3}}" />

Integration tests can be run via:

npm run test:integration

These tests will run via karma, one at a time, in your system's default Chrome and then Firefox.

Content Security Policy (CSP)

Use the following policy directives to enable CSP that is compatible with twilio-client.js.

media-src mediastream
connect-src wss://

If you are providing a non-default value for Device.Options.edge or Device.Options.region parameter, you need to add the Signaling URI wss://chunderw-vpc-gll-{regionId} in your connect-src directive where regionId is the Region ID as defined in this page. See examples below.

If Device.Options.region is us1

connect-src wss://

If Device.Options.edge is ashburn

connect-src wss://

If Device.Options.edge is ['ashburn', 'sydney', 'roaming']

connect-src wss:// wss:// wss://





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