Calls are billed to the account the key belongs to. You can create as many keys
as you like — for example, one per environment or per service — and revoke any
of them without affecting the others.
A missing, malformed, or revoked key returns 401 Unauthorized:
{ "status": "error", "message": "Invalid API key"}
If your account is out of credits, calls return 402 Payment Required. Top up
from the Billing page of your dashboard. See
Responses & errors for the full list of status codes.