Skip to main content


Welcome to the technical documentation for the JavaScript Browser SDK.

voice calls, dialing the PSTN, and connecting to SIP endpoints

This latest version of the RELAY Browser SDK is ideal for Chat applications and streaming or conferencing with audio and video. If you need to add browser support for voice calls or dial the PSTN or SIP endpoints, please use our previous version of the Browser SDK.


Install locally

npm install @signalwire/js

Or include it in your client using our CDN

<script src=""></script>

Get started

This SDK is meant to be used in the browser, and gives you access to four different namespaces:

  • Video gives you access to the classes and methods that let you interface with the backend Video APIs.
  • Chat gives you access to the classes and methods that you need to create a real-time chat application.
  • PubSub is the foundation layer of Chat. It gives you access to the most basic classes and functions to subscribe to channels, publish messages, and receive messages.
  • WebRTC contains several functions that are useful for interacting with the hardware of the user's device.

Don't know where to start? Create an instance of Video.RoomSession to join a room, use the Chat.Client constructor to start a chat application, or take a look at the Simple Video Demo or Simple Chat Demo walkthroughs.