Connect an agent over MCP
Give Claude, Cursor or any MCP client the published specs in this registry, so it writes against the real contract instead of guessing.
Find the right API
Search the registry by what an API does, not by what it is called, and get back the listings that match.
Read the contract
Pull a full OpenAPI document, a single operation, or one schema — so the agent writes against the real contract instead of guessing field names.
Follow the changes
Ask what changed between two versions of a published API, and get the changelog the registry computed from the specs themselves.
Set it up
1.Add the server to your client
Writes the config for Cursor and Claude. Add --client cursor or --client claude for just one.
terminalnpx @spec0/cli mcp install2.Restart the client and sign in when it asks
The client opens a browser window the first time it calls a registry tool. There is no token to copy and no
Authorizationheader to paste — approve it once and the client keeps the session.3.Ask it something
Anything in this registry is addressable as
org/api.“Using Spec0, look at adyen/checkout-api and write me a typed client for creating a payment session. Use the response schema from the spec, not your memory of it.”
No Spec0 account yet?
Reading the registry from an agent needs one. It is free.