Module mcp 

Protocol-specific application logic shared by more than one entry point.

These modules are MCP-shaped rather than transport-shaped, and more than one caller needs them: a server answers a handshake, a bridge answers the same handshake on its downstream leg. Anything here that both needed would have been written twice otherwise, and two readings of a wire format is how a bridge ends up disagreeing with the server it sits in front of.

Post-MVP protocols slot in beside initialize in this directory.

Modules

initialize

The initialize exchange, as both a server and a bridge read it.

input_required

SEP-2322 multi round-trip requests, introduced at 2026-07-28.

param_headers

Mcp-Param-{Name}: tool arguments a client mirrors into HTTP headers.

request_meta

The per-request _meta block SEP-2575 introduced at 2026-07-28.

subscription

subscriptions/listen, independent of the transport that carries it.