Errors

The Duta API uses standard HTTP status codes. Error responses include a message you can show or log.

Status	Meaning	Common cause and fix
401	Authentication failed	Missing or invalid API key. Check the Authorization: Bearer header.
402	Quota exceeded	You hit your plan’s monthly send limit. Upgrade in the dashboard.
403	Permission denied	The sender domain is not verified for your account, or the key lacks the required scope. Verify the domain.
422	Unprocessable	Invalid sender, or a recipient is on your suppression list. The response lists blocked addresses.
429	Rate limited	Too many requests per second, or the free-plan daily cap. Slow down or upgrade.
500	Server error	Transient. Retry with backoff; contact support if it persists.

Error shape

Most errors return:

{ "error": "Sender domain not verified for this account" }

Rate-limit errors return:

{ "statusCode": 429, "name": "rate_limit_exceeded", "message": "Too many requests." }

The TypeScript SDK normalises both shapes into a single DutaError with a stable name, so you can branch on error.name reliably.