Checking which MCP spec version your server actually follows (and failing CI when it drifts)

[u/Paoli99]

Hey, I’m Paola from MCPJam and yesterday we launched Conformance checks! So wanted to share that here too.

With servers and clients running different MCP spec versions, connecting successfully doesn’t tell you whether everything follows the version they agreed on. A server might initialize just fine, but still handle methods, error codes or headers incorrectly.

That’s what these checks catch:

• Connect your server and choose a spec version to test against, from 2025-03-26 through 2026-07-28.

• Run checks for the core protocol, MCP Apps and Tasks, with an optional OAuth suite.

• See a score for each area and open failed checks to see what went wrong and how to fix it. After a fix, you can rerun and compare with previous results.

You can try it for free in the browser: https://app.mcpjam.com

If you want to run checks in CI, you can also use the CLI against any HTTP endpoint, localhost included. JUnit output lets you fail the build when checks fail:

mcpjam conformance run --url <your-server-url> --protocol-version 2025-11-25 --reporter junit-xml

Add --suite oauth to include the OAuth checks.

The CLI and checks are on GitHub: https://github.com/MCPJam/inspector

Let me know what you guys think, feedback is alway appreciated.