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

Ready

Primary summary from verified readiness

Evidence strength Critical

Decision

Human editorial judgment · 2026-08-20

Proceed with caution

Why: Spec is officially final-dated and backed by the Linux Foundation/AAIF, but it is the biggest breaking revision yet and the stateless benefit has a documented streaming/subscription-state caveat, so adopt deliberately rather than racing the RC.
Next: Build a shadow branch targeting the RC: drop Mcp-Session-Id stickiness, add .well-known/oauth-protected-resource + per-request MCP-Protocol-Version, wire Mcp-Method routing, and run multi-instance round-robin tests before the 2026-07-28 cutover; keep current spec in prod until Tier-1 SDKs validate.

Constraints

No named blocker is present in the current public projection.

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 13