Model Context Protocol

What is Streamable HTTP (MCP transport)?

Definition: Streamable HTTP is the current transport for remote MCP servers: a single HTTPS endpoint that accepts POSTed JSON-RPC and replies with either a plain JSON response or a Server-Sent-Events stream, with optional sessions via the Mcp-Session-Id header.

It superseded the older two-endpoint HTTP+SSE transport, collapsing everything to one endpoint. The client POSTs with Accept: application/json, text/event-stream; the server chooses JSON or SSE per request. For local tools, stdio is used instead.

Which MCP transport should a remote server use?

Streamable HTTP — it's the single-endpoint standard current clients expect. The legacy HTTP+SSE transport is superseded; stdio is for local subprocess servers.

Put it into practice

MCP transports explained →

Related terms

Model Context Protocol (MCP)MCP server