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. Checks run on an isolated worker with restricted networking and resource limits. Public web access is allowed. Handshake deadline: 150s.
A real handshake over stdio
We start the package and complete a live MCP session: initialize → tools/list. This checks startup and tool discovery; individual tool behavior and your client configuration still need testing.
Failures name the likely cause
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.
Isolated from the directory
Package checks run in disposable containers on a separate worker. Private-network access is blocked, resources are capped and the handshake has a 150-second deadline. Public web access remains available.
Passing server? List it in the vault. Claim it and verification runs automatically.