Model Context Protocol revises its specification
Specification revision — removes protocol-level sessions and Mcp-Session-Id, drops the initialize handshake, makes server/discover mandatory, has the MRTR pattern replace server-initiated requests, announces the end of support for Roots, Sampling, Logging and OAuth DCR, and introduces a 12-month deprecation grace policy
Why it matters
MCP is redesigned from the ground up, from a protocol of stateful sessions into a stateless, per-request one. The largest break in backward compatibility yet
Source — Primary sources first; secondary reports are labelled “Press”
Officialmodelcontextprotocol.iohttps://modelcontextprotocol.io/specification/2026-07-28/changelogAdded in Week 35, 2026 · See that week