Streamable HTTP
Core Facts
At the end of March 2025, MCP added the Streamable HTTP communication mechanism, which has become the current mainstream approach.
Remote MCP services adopt the Streamable HTTP mode, based on HTTP/1.1 or HTTP/2 protocols, with support for Server-Sent Events (SSE).
In early 2025, the community proposed the Streamable HTTP transport method as a replacement for SSE.
Timeline (last 90 days)
In the MCP specification, Sampling, Roots, and Logging have been marked as deprecated and can still be used for at least 12 months; the long-running Tasks capability has been moved out of the core to become an official extension; SSE is the deprecated legacy transport method—local processes use Standard IO, and remote services use Streamable HTTP.
When calling an MCP server that uses the Streamable HTTP transport, the HTTP request's Accept header must include both application/json and text/event-stream, otherwise the server returns 406.
MCP transport changed in Spring AI 2.0: Streamable HTTP replaces the deprecated SSE and becomes the default transport protocol.
For individual developers, stdio is usually the safer starting point; only when tools need to be shared across devices or teams is it worth taking on the operational cost of Streamable HTTP.
Alguard's Tier 1 is an MCP server (mcp_server/server.py) that exposes three tools—attempt_purchase, get_session_status, get_audit_trail—via Streamable HTTP, and no approve tool exists.
STDIO is suitable for local operation and is the optimal choice for Claude Desktop and Claude Code to call local servers; for remote deployment or team sharing, Streamable HTTP should be used instead, which is the officially recommended remote transport method.
CrewAI only supports streamable HTTP type MCP servers.
When using streamable HTTP transport, the client and server can be located anywhere, but the server must be running before the client can connect.
In early 2025, the community proposed the Streamable HTTP transport method as a replacement for SSE.
All Facts (13)
At the end of March 2025, MCP added the Streamable HTTP communication mechanism, which has become the current mainstream approach.
80%VerifiedRemote MCP services adopt the Streamable HTTP mode, based on HTTP/1.1 or HTTP/2 protocols, with support for Server-Sent Events (SSE).
80%VerifiedIn early 2025, the community proposed the Streamable HTTP transport method as a replacement for SSE.
65%UnverifiedStreamable HTTP implements bidirectional streaming communication based on the standard HTTP protocol, resolving the network traversal issues that SSE faces in enterprise proxy and load-balancing environments.
60%UnverifiedIn the MCP specification, Sampling, Roots, and Logging have been marked as deprecated and can still be used for at least 12 months; the long-running Tasks capability has been moved out of the core to become an official extension; SSE is the deprecated legacy transport method—local processes use Standard IO, and remote services use Streamable HTTP.
50%UnverifiedWhen calling an MCP server that uses the Streamable HTTP transport, the HTTP request's Accept header must include both application/json and text/event-stream, otherwise the server returns 406.
50%UnverifiedMCP transport changed in Spring AI 2.0: Streamable HTTP replaces the deprecated SSE and becomes the default transport protocol.
50%UnverifiedFor individual developers, stdio is usually the safer starting point; only when tools need to be shared across devices or teams is it worth taking on the operational cost of Streamable HTTP.
50%UnverifiedAlguard's Tier 1 is an MCP server (mcp_server/server.py) that exposes three tools—attempt_purchase, get_session_status, get_audit_trail—via Streamable HTTP, and no approve tool exists.
50%UnverifiedSTDIO is suitable for local operation and is the optimal choice for Claude Desktop and Claude Code to call local servers; for remote deployment or team sharing, Streamable HTTP should be used instead, which is the officially recommended remote transport method.
50%UnverifiedCrewAI only supports streamable HTTP type MCP servers.
50%UnverifiedWhen using streamable HTTP transport, the client and server can be located anywhere, but the server must be running before the client can connect.
50%UnverifiedStreamable HTTP支持有状态和无状态两种操作模式
50%