SSE
Server-Sent Events — a one-way HTTP streaming protocol used for LLM token streaming and MCP HTTP transport.
Definition
Server-Sent Events is a simple text-based streaming protocol where a server pushes events to a client over a long-lived HTTP response using the text/event-stream media type. It powers LLM token streaming from the Anthropic and OpenAI APIs, real-time dashboards, and MCP's HTTP/SSE transport. Browsers expose it via the EventSource API.