# Streamable HTTP

> The MCP transport, introduced in spec version 2025-03-26, that carries client-server messages over a single HTTP endpoint and supersedes the older HTTP+SSE transport.

_The Agentic Web Lexicon · /glossary/streamable-http · [JSON](/api/glossary/streamable-http) · [all The Agentic Web Lexicon](/glossary)_

- **term:** Streamable HTTP
- **category:** protocols
- **short_def:** The MCP transport, introduced in spec version 2025-03-26, that carries client-server messages over a single HTTP endpoint and supersedes the older HTTP+SSE transport.
- **long_def:** Streamable HTTP replaces MCP's original 2024-11-05 HTTP+SSE transport with a single-endpoint design: the server handles POST and GET requests and may optionally use Server-Sent Events to stream multiple messages, but can also run fully statelessly behind a load balancer. The TypeScript SDK v1.10.0 (17 April 2025) was the first to support it.
- **see_also:** mcp, content-negotiation
- **etymology_origin:** Introduced in the Model Context Protocol specification version 2025-03-26 as the recommended remote transport, superseding the HTTP+SSE transport from spec version 2024-11-05.
- **related_to:** mcp, tool-use, webmcp
- **contrast_with:** Unlike the deprecated HTTP+SSE transport, which required a persistent server-sent-events connection, Streamable HTTP uses a single endpoint and can run statelessly behind a load balancer — SSE becomes optional rather than mandatory.
- **example:** MCP introduced Streamable HTTP in spec version 2025-03-26; the TypeScript SDK v1.10.0 (17 April 2025) was the first release to support it.
- **source:** https://modelcontextprotocol.io/specification/2025-03-26/basic/transports
- **status:** active
- **why_it_matters:** Streamable HTTP is the transport a site uses to host a scalable remote MCP server; choosing it over deprecated SSE is a concrete agent-readiness implementation decision.
- **sameAs:** —
- **bridge_entity:** protocols/capability/mcp
- **last_verified:** 2026-06-15
- **md_twin:** /glossary/streamable-http.md