Two years ago this month Anthropic open-sourced the Model Context Protocol (25 November 2024). In December 2025 it was donated

to the Agentic AI Foundation, a directed fund under the Linux Foundation co-founded by Anthropic, Block and OpenAI with support

from Google, Microsoft, AWS, Cloudflare and Bloomberg - so today it is a shared standard rather than one vendor's plugin system.

Its current specification revision is dated 2026-07-28 , and that revision does something most explainer posts miss: it makes

the protocol stateless . The initialize handshake is gone, sessions and the Mcp-Session-Id header are removed from

Streamable HTTP, every request carries its own protocol version and client capabilities in _meta , and servers must implement a

server/discover RPC to advertise versions and identity. Roots, Sampling and Logging were deprecated outright, with a

twelve-month removal window.…