Action Cable

Action Cable is the WebSocket framework integrated into Ruby on Rails, providing real-time communication capabilities for Rails applications. The npm package 'actioncable' (current stable version 5.2.8-1, though the Rails ecosystem recommends using the latest 7.x or 8.x series) is the JavaScript client library that connects to an Action Cable server. It allows developers to subscribe to channels and receive broadcasts in the browser or any JavaScript runtime. Key differentiators: tight integration with Rails (session/cookie-based authentication, same MVC patterns), full-stack offering with both server- and client-side components, and pub-sub streaming model. Release cadence follows Rails releases, with frequent minor and patch updates. Alternatives include pure WebSocket libraries or Pusher, but Action Cable is the default for Rails real-time features.