Errors

Code	Meaning
400	Malformed request — check required fields
401	Missing/invalid/expired bearer token — log in again. On the order endpoints (/api/web/*): missing or invalid x-access-key / x-secret-key
403	Account blocked, or valid token without permission for this resource
404	Resource not found — for Get order, an order number that isn’t one of your orders
429	Rate limited — back off and retry

Error responses use the same envelope with success: false and a human-readable message.