Claude Code skills · updated 2026-10-03

MCP spec migration skill for Claude Code — removed methods, transports by line

13 findings in one MCP server file, each with what 2026-07-28 changed

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.

Get it on Whop - $12 onceGet it on Gumroad

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 it printed on the bundled example

== MCP Server Lint — 13 findings (12 errors, 1 warning) in 1 file · 27 rules
  ERROR server.ts:2  [mcp_25]
        SDK transport class for the Deprecated HTTP+SSE transport.
        fix: StreamableHTTPServerTransport / StreamableHTTPClientTransport
  ERROR server.ts:4  [mcp_7]
        The initialize handshake was REMOVED in 2026-07-28. MCP is stateless: protocol version and client capabilities ride in _meta on every request.
        fix: Implement server/discover; read _meta["io.modelcontextprotocol/clientCapabilities"]
  ERROR server.ts:5  [mcp_11]
        ping was REMOVED in 2026-07-28.

What you get

• SKILL.md, an offline Node scanner and the 27-rule table
• file:line, severity and what 2026-07-28 changed
• The replacement to use, applied only after you agree
• CI: node scripts/scan.js . exits 1 on any error

Install

Unzip into ~/.claude/skills/ (all projects) or your-repo/.claude/skills/ (one repo), 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+.

unzip mcp-server-spec-check.zip -d ~/.claude/skills/

Ask Claude

“Clients are moving to the new MCP protocol version. Is the MCP server in this repo still compatible? Don't edit anything yet.”

What it does not do

It does not connect to your server; it reads source text line by line. No network calls, no edits without your OK.

FAQ

What is a Claude Code skill?

A folder with a SKILL.md and scripts that Claude Code loads when your request matches it. You ask in plain words and Claude runs the scanner the skill carries.

How is this different from asking Claude without the skill?

The skill carries a dated rule table and a scanner that reads every file, so Claude quotes the exact date and line instead of answering from memory.

Does it send my code anywhere?

It does not connect to your server; it reads source text line by line. No network calls, no edits without your OK.

How do I install it?

Unzip into ~/.claude/skills/ (all projects) or your-repo/.claude/skills/ (one repo), 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 do I get when I buy?

The zip. On Whop it is in your library as a download lesson with the zip attached; on Gumroad it is the product file.