MCP 2026-07-28 Specification (Stateless Core + Extensions)

A dated reading of what is claimed, reported, and independently verified in the current evidence.

Current reading

Readiness band and full integer triple

AI-assisted assembly · derived results

Readiness band

Watch

Primary summary from verified readiness

Evidence strength Critical

Decision

Agent-assisted assessment · independently reviewed · 2026-10-01

Use the final stateless core with staged migration and explicit extension qualification.

Why: Independent implementation tests cover substantial core and extension behavior, while deployment acceptance and cross-host interoperability remain implementation-specific.
Next: Pin releases and test per-request capabilities, extension fallback, authorization, subscriptions, disconnects and safe retries under the intended deployment conditions.

Constraints

Optional extensions require bilateral compatibility testing.
Source-level conformance does not establish acceptance of every released package.
Application state and replay protection remain deployment responsibilities.
Transport and lifecycle changes require migration testing.

Evidence summary

AI-assisted assembly

Counts and dates only. Raw signals, private excerpts, trust records, and internal corpus material are not published here.

Publication record

Revision 19