MCP Explained

Model Context Protocol

Spec version

Message flow

#	From	To	Method	Info

Not in the MCP spec

A harness implementation detail, not part of MCP. Nothing new on the wire: the client and servers still speak plain tools/list and tools/call.

Message

MCP spec 2025-11-25. Token counts are illustrative.
Made by Runlayer, the secure MCP gateway for teams.