Troubleshooting

"npx: command not found"

Make sure Node.js (v18+) is installed:

node --version
npm --version

Install from nodejs.org if needed.

Tools not showing up

1. Restart the app after editing the config file
2. Check the config path — make sure you edited the right file
3. Validate JSON — use a JSON validator to check for syntax errors
4. Check logs — Claude Desktop and other apps may have logs showing connection errors

"calc-mcp: command not found" inside a Node.js project

If you run npx inside a directory that contains node_modules, npx may fail with:

sh: calc-mcp: command not found

This happens because npx resolves the scoped package locally but fails to link the binary correctly. All the examples on this page already include the fix (--prefix /tmp), which forces npx to use a separate directory for package resolution:

npx --prefix /tmp -y @coo-quack/calc-mcp@latest

Version info

To check the latest published version:

npx --prefix /tmp -y @coo-quack/calc-mcp@latest --version

Still stuck?

Open an issue on GitHub.