fastmcp/docs/servers/providers
Jeremiah Lowin 0ba3db1a56
Mirror the frontend's protocol era on a proxy's backend connection (#4573)
* Mirror front protocol era onto proxy backend connection

A proxy created from a non-Client target now negotiates, on its backend,
whatever era its front client negotiated, instead of pinning one era.
Explicit create_proxy(mode=...) still overrides. Guards the eager backend
initialize() so an explicit modern pin behind a handshake front no longer
crashes.

* Carry the mirrored proxy era into multi-server config backends

A multi-server MCPConfig target mounts one proxy per configured server on a
composite router, so setting the era on the outer client stopped at the router
and every real backend stayed on its default era. TransportOptions.backend_mode
carries it down, resolved per request alongside the outer mirroring.

The router is also sealed under a policy held on the transport rather than a
fresh per-router ephemeral key, so a guard tool's request_state survives the
router being rebuilt between rounds.
2026-07-20 12:31:02 -04:00
..
custom.mdx Migrate to MCP SDK v2.0.0b2 (httpx2) (#4503) 2026-07-18 15:12:47 -04:00
filesystem.mdx Rename filesystem-provider example dir to avoid mcp/ collision (#3878) 2026-04-12 17:01:58 -04:00
local.mdx Align server component docs (#4260) 2026-07-19 14:23:36 -04:00
overview.mdx Align server component docs (#4260) 2026-07-19 14:23:36 -04:00
proxy.mdx Mirror the frontend's protocol era on a proxy's backend connection (#4573) 2026-07-20 12:31:02 -04:00
skills.mdx Align server component docs (#4260) 2026-07-19 14:23:36 -04:00