The Model Context Protocol published the 2026-07-28 specification and shipped matching SDK updates.

The Model Context Protocol team published the 2026-07-28 specification and announced that the SDKs needed to build clients and servers are available alongside it. The release makes the protocol stateless, moving MCP from a bidirectional stateful model to a request-response design that carries protocol version, client identity, and capabilities on each request. The announcement also says the release includes authorization hardening changes, including RFC 9207 issuer validation and a shift away from Dynamic Client Registration toward client metadata documents. It further introduces a formal deprecation policy so the protocol can evolve without breaking existing deployments.

Why it matters: Agent developers can now target a simpler HTTP scaling model while preparing for updated auth and deprecation rules that will shape server compatibility.