The Model Context Protocol, the open standard that lets AI agents talk to external tools, has shipped its largest revision since launch. The 2026-07-28 release candidate, finalized July 28, makes the protocol stateless at its core, removing the handshake and session IDs that previously pinned clients to specific servers.
The change means a remote MCP server can now sit behind a plain round-robin load balancer with no sticky sessions or shared session stores, a shift that makes horizontal scaling dramatically simpler. Requests carry protocol version and method in headers, and clients can cache tool listings for as long as servers allow.
The update also makes extensions first-class. MCP Apps introduces server-rendered user interfaces, while the Tasks extension handles long-running work. Authorization now aligns more closely with OAuth and OpenID Connect, roots, sampling, and logging are deprecated, and tools get full JSON Schema 2020-12 support.
A formal deprecation policy means future revisions should stop breaking existing integrations, and new features will stabilize as opt-in extensions before entering the core spec. The release candidate was locked in May to give SDK maintainers and clients a ten-week validation window, and the final specification now ships under the stewardship of the Agentic AI Foundation.
