Originally published on AI Tech Connect.
What breaks first Start with the uncomfortable part, because the release-candidate period is over and the specification blog has now published 2026-07-28 as final. If you have an MCP server serving real traffic this week, here is what stops matching the spec. Your handshake. The initialize and initialized exchange is removed (SEP-2575 and SEP-2567). Any code path that waits for a handshake before accepting calls no longer has a handshake to wait for. Your session identifier. The Mcp-Session-Id header is removed. Protocol-level sessions are gone entirely. Anything hanging off that session. Negotiated capabilities, the client's declared protocol version, per-connection scratch state — all of it used to arrive once at handshake time and be looked up thereafter. Now the protocol version plus…
Top comments (0)