WebSocket support is now in Public Beta

Vercel has launched WebSocket support in public beta for its Functions, enabling bidirectional communication for realtime features like AI streaming and chat. The WebSocket connections run on Fluid compute with billing only for active CPU time, not idle connections, and support standard Node.js libraries.

Vercel Functions can now serve WebSocket connections, enabling bidirectional communication between clients and server-side code on Vercel. Use WebSockets for realtime features such as interactive AI streaming, chat, and collaborative apps. WebSocket connections run on Fluid compute https://vercel.com/docs/fluid-compute and follow the same limits https://vercel.com/docs/functions/limitations and pricing https://vercel.com/docs/functions/usage-and-pricing as other Function invocations. With Active CPU pricing https://vercel.com/docs/functions/usage-and-pricing , billing only applies to the time your Function spends processing messages, not idle connection time. You can serve WebSocket connections using standard Node.js libraries, with no additional configuration: Higher-level libraries like Socket.IO http://socket.io/ are also supported. Read the documentation https://vercel.com/docs/functions/websockets to get started.