Free tool
Test your MCP server
Paste an npm package, a GitHub repository, or an npx/uvx command. We run a live MCP handshake and hand you a shareable report: verdict, protocol version, tools list, and if it fails, why.
3 free tests per day. Sign in with GitHub for 15. The command runs sandboxed (no network beyond package install, memory/CPU capped, killed after 150s).
A real handshake, not a lint
We spawn your server exactly like Claude or Cursor would and complete a live MCP session over stdio: initialize → notifications/initialized → tools/list. If it passes here, it works in a client.
Failures come with a diagnosis
Scaffolder instead of a server, missing API key, interactive CLI, wrong runner. The report names the likely cause in plain language, with the stderr tail to prove it.
Sandboxed and capped
Commands run in a landlock+seccomp sandbox under systemd resource caps with a hard 150-second timeout. Only npx and uvx launchers are executed, never shell.
Passing server? List it in the vault. Claim it and verification runs automatically.