On the bundled sample: 13 findings (12 errors, 1 warning) in 1 file from 27 rules - initialize, ping, logging/setLevel, Mcp-Session-Id, Last-Event-ID and SSEServerTransport.

Who it’s for
Developers and teams who maintain an MCP server or client in TypeScript, JavaScript or Python and ship it to Claude, VS Code or other MCP hosts.

What breaks, and when
The 2026-07-28 revision removed the initialize handshake, ping, logging/setLevel and the Mcp-Session-Id header. MCP is stateless: protocol version and client capabilities ride in _meta on every request.

What you get
• SKILL.md, an offline Node scanner and the 27-rule table
• file:line, severity and what 2026-07-28 changed

See it first
The real output of the bundled example is on getreadystack.com/skills/mcp-server-spec-check/ — free, no sign-up, so you see what it finds before you pay.

Install in 30 seconds
Unzip into ~/.claude/skills/, then ask Claude Code: “Clients are moving to the new MCP protocol version. Is the MCP server in this repo still compatible? Don’t edit anything yet.”. Needs Node 16+.

What it does not do
It does not connect to your server; it reads source text line by line.

FAQ
Q: How is this different from asking Claude without the skill?
A: The skill carries a dated rule table and a scanner that reads every file, so Claude quotes the exact date and line instead of guessing from memory.
Q: How do I get the files?
A: In your Whop library after paying: the lesson “mcp-server-spec-check.zip”.