Backend WebSocket Patterns

Purpose

Design consistent, production-grade WebSocket services. Every connection must follow the same conventions for handshake, message framing, room management, reconnection, error handling, and cross-node scaling.

Agent Protocol

Trigger

Exact user phrases: "WebSocket", "real-time", "socket.io", "WS connection", "reconnection", "WS rooms", "broadcast", "WS scaling", "WS clustering", "pub/sub over WS", "SSE", "Server-Sent Events", "long polling", "WS handshake", "design a WebSocket server".

Input Context

Before activating, verify:

• The real-time feature being designed is known.
• The transport (raw WebSocket / Socket.IO / SSE) is chosen. If not, ask: "Raw WebSocket, Socket.IO, or SSE?"
• The scaling requirement (single node vs multi-node) is known.
• The authentication model is known.

Output Artifact

No file output unless the user requests it. Produces WebSocket connection specs and message protocols as text.