ActionCable is a new framework for real-time communication over websockets and it will be part of Rails 5. I am not going to get into too much detail about it, you can read the very detailed readme of the project on this link: ActionCable . The websockets server is running in a separate process from the main Rails application which means you need to authenticate your users there too. In the example app , David used a simple cookie based authentication in the app itself and re-validated the cookie at the websocket connection. This is good for demonstration, but many of the Rails based apps are using Devise for authentication so I want to share, how I solved the authentication with Devise. The websocket server doesn't have a session, but it can read the same cookies as the main app, so I figured, I will just set a cookie with the user id and verify that at the socket connection. To do this, I used a Warden hook: # app/config/initializers/warden_hooks.rb Warden ::...