Socket.IO

The standard JavaScript library for real-time, bidirectional and event-based communication, supporting fallback to long-polling.

Overview

Socket.IO enables real-time communication between client and server. It is not a managed service but a library you run on your own Node.js server. It provides a simple event-driven API (`emit`, `on`) and handles connection fallbacks for browsers that don't support WebSockets. It remains the most popular choice for custom real-time logic due to its flexibility and vast community support.

Best for

• Custom multiplayer games
• Real-time collaborative tools with complex logic
• Legacy browser support

Trade-offs

What XeroHack pre-wires

When you pick Socket.IO in the interview, the engine emits these files into your scaffold:

• io.connect()
• socket.emit()
• socket.on()