HTTP status codes

Status codes returned by the Newsletter API.

Code	Meaning
200	OK — query or update successful.
201	Created — resource created.
400	Bad request — malformed JSON, invalid list or invalid status filter.
401	Unauthorized — missing or invalid API key.
403	Forbidden — API access disabled or module capability disabled.
404	Not found — subscriber does not exist.
413	Payload too large.
415	Unsupported media type — use application/json.
422	Validation error — field-level errors.
429	Rate limit exceeded or temporary lockout.

See Response format for the error envelope, and Rate limits for the 429 payload.