 <p>You'll need the client-side library to connect to the server. You can fetch it at your domain.com/socket.io/socket.io.js and cache it locally. From there you can access global io and then connect with: </p> <pre><code>var socket = io.connect(); </code></pre> <p>It may be even better to copy the library into your application and have a background service that fetches the newest version every x days/weeks.</p>