Realtime

Server-Sent Events (SSE)

A unidirectional server-to-client streaming protocol over HTTP, defined by the WHATWG HTML Living Standard. SSE is simpler than WebSocket — it reuses HTTP and supports automatic reconnection — but is one-way only. It has seen a resurgence as the carrier for LLM token streams from OpenAI, Anthropic, and other AI APIs.

GitHub

Documentation

📖
Documentation
https://developer.mozilla.org/en-US/docs/Web/API/Server-sent_events

Other Resources

🔗
Specification
https://html.spec.whatwg.org/multipage/server-sent-events.html

API entry from apis.yml

apis.yml Raw ↑ 
aid: realtime:server-sent-events
name: Server-Sent Events (SSE)
description: A unidirectional server-to-client streaming protocol over HTTP, defined by the WHATWG HTML
  Living Standard. SSE is simpler than WebSocket — it reuses HTTP and supports automatic reconnection
  — but is one-way only. It has seen a resurgence as the carrier for LLM token streams from OpenAI, Anthropic,
  and other AI APIs.
humanURL: https://html.spec.whatwg.org/multipage/server-sent-events.html
baseURL: https://
tags:
- SSE
- Server-Sent Events
- Protocol
- Unidirectional
- Standard
properties:
- type: Specification
  url: https://html.spec.whatwg.org/multipage/server-sent-events.html
- type: Documentation
  url: https://developer.mozilla.org/en-US/docs/Web/API/Server-sent_events