Errors

Errors return a JSON body of {"ok": false, "error": "<message>"}.

Status	`error`	Cause
401	Missing API key	No key, or the value doesn't start with `fxk_`.
401	Send the key in the Authorization (Bearer) or X-API-Key header	The request had an `api_key` query parameter.
401	Invalid, expired or revoked API key	Unknown, expired or revoked key.
403	This key lacks the read:… scope	The key lacks the scope for this endpoint.
400	limit and before must be numbers	Bad paging parameters.
404	Not found	Unknown resource.

Requests to paths outside the four documented endpoints may get a plain-text 404 from the platform rather than JSON. Unexpected server errors return 5xx; retry with backoff.