№ 00 — MEMBERS ONLY
MCP in August 2026: the handshake is gone, three primitives are on a removal clock, and the spec still promises more than your client will run
2026-08-13PRIVATE≈ 17 min read
The 2026-07-28 revision deleted the initialize handshake, the session ID, and every server-initiated request, then deprecated Roots, Sampling and Logging with a twelve-month clock. This is the wire-level state of MCP as a production builder needs it: exact method names and shapes, which SDK actually changes what you speak on upgrade, the token bill nobody quotes, and the features the spec offers that no client will actually run.
WHAT'S INSIDE
- 01The revision is dated 2026-07-28, and "MCP 2.0" is a phrase that will break your migration plan
- 02Declare your protocol version on every request, because there is no handshake left to negotiate it
- 03Stateless does not mean you cannot keep state, it means the state gets a name and travels in the open
- 04Elicitation was not improved, it was inverted, and the new shape is a retry
- 05A feature in the specification is not a feature you can ship
- 06Roots, Sampling and Logging are deprecated, so build the replacement into your next server now
- 07Tool schemas got looser and one error code changed under you
- 08The new headers are the gift to whoever operates your traffic
- 09Extensions are how the protocol grows now, and Tasks already moved out of core
- 10Six SEPs hardened authorization, and one of them finally unbreaks desktop clients
- 11MCP is the wrong answer when you own both ends and the tool count is small
- 12The four SDKs disagree about what upgrading does to your wire format
- 13Nothing broke on July 28, and that sentence is the most misread line in the migration
- 14What to actually do this week