WebSockets

Full-duplex, persistent, bidirectional communication over a single TCP connection. Defined in RFC 6455 (2011). Used for chat, real-time dashboards, collaborative editing, multiplayer games, push notifications — anything where the server needs to send to the client without polling.

For comparison with SSE / long-polling see 03_websocket_vs_alternatives.md. For nginx-side proxying see ../nginx/10_websocket_proxying.md.

Files

#	Topic
01	WebSocket protocol — handshake, frames, codes
02	Python implementation — websockets, FastAPI, Channels
03	WebSocket vs alternatives — SSE, long-poll, gRPC
04	Authentication
05	Connection management — heartbeats, reconnection, backpressure
06	Security
07	Scaling — broker fan-out, sticky sessions

../sse/ — Server-Sent Events
../nginx/10_websocket_proxying.md — nginx reverse proxy for WebSockets
../../28_networking/02_tcp_vs_udp.md — TCP fundamentals
../../07_rest_apis/09_stateful_vs_stateless.md — statefulness implications