Only 1 of 4,356 reachable MCP servers passes the new checks
A scan on July 12, 2026 tested all 7,850 s listed in the official and could openly reach 4,356 of them. Only one reachable server passed all three checks required for the scheduled for July 28. The tool classified 90.8% as not ready; other servers could not be judged conclusively because of , unclear responses, or similar limits.
The new removes the initial connection handshake and , and it requires on every request. Existing servers will not suddenly stop working on July 28. Version negotiation will continue, and deprecated features will remain available for at least 12 months.
The open-source mcp-spec-check tool can test a live server address in about 30 seconds without reading its code or installing anything on the server. It also returns exit codes 0, 1, or 2 for ready, failed, or unable to test, making it usable in automated deployment checks.
Key points
- The scan covered all 7,850 s in the official registry and reached 4,356 without credentials.
- Only one reachable server passed all three required readiness checks.
- The tool marked 90.8% of reachable servers as not ready.
- July 28 is the publication date, not a shutdown date; deprecated features remain for at least 12 months.
- Teams can run npx mcp-spec-check with a server address for a roughly 30-second test.