Streamable HTTP support

[hanxuanliang]

The latest draft specification of MCP states that streamable HTTP will be the supported communication protocol, replacing HTTP + SSE. It would be better if fastmcp provided support for this.

References:

[1] https://modelcontextprotocol.io/specification/2025-03-26/basic/transports#streamable-http

[shira-ayal]

Hi @hanxuanliang ! Thanks for submitting this.
We are following up close on the new specification, but as the mcp-clients currently only support SSE, we are not adjusting just yet.
Having said that, we are very open to contribution so if you (or anyone else) would like to pick this up we would be happy to review a PR!

[shahar4499]

Pinned this issue as it is one of the upcoming things, right after we implement auth support.

[mcfredrick]

Is there any update on this? I'd love to use this in a project. But SSE is a non-starter in kubernetes.

[cb-bharathvaj]

+1 Any update on supporting Streamable HTTP

[magicbrighter]

+1 Any update on supporting Streamable HTTP

[chariswang188996]

+1 Any update on supporting Streamable HTTP

[UnfetteredScholar]

+1 Any update on supporting Streamable HTTP

[crazyqsl]

+1 Any update on supporting Streamable HTTP

[Hujun]

+1 Any update on supporting Streamable HTTP

[Jerry-Kon]

+1 Any update on supporting Streamable HTTP