Server-Sent Events (SSE)

One-way streaming

Why it exists

Simpler than WebSockets when you only need server → client
Uses plain HTTP (no upgrade)
Auto-reconnect and event IDs built into the spec

Tradeoffs

One direction only (no client → server over same connection)
Often limited to 6 connections per domain (browser)

GET /api/sse/stream — connection stays open, server pushes events

Stream

Disconnected

One-way stream — server → client

S

Server

events

C

Client

Event log

Connect to the stream to see server-sent events.