Revoke one of your API keys

Kills a key immediately: the very next request made with it is refused with 401 invalid_api_key. There is no propagation delay and no cache to wait out. You may revoke the key you are authenticating with — that is the correct move when it has leaked, though you will then need another key, or the email flow, to get back in; rotate does both in one call. A key belonging to another account, or to another API, answers 404 exactly as an unknown id does, so this cannot be used to probe for keys you do not own. Idempotent, and free.