Error Handling - Heyy Help Center

The Heyy API uses conventional HTTP response codes to indicate success or failure. Response codes in the 2xx range indicate success. Codes in the 4xx range indicate a client error—the request failed given the information provided. Codes in the 5xx range indicate an error on Heyy’s servers.

HTTP error codes in use

The API uses the following HTTP codes to communicate errors:

HTTP Code	Error type	Description
400	Client error	Returned when there is a type mismatch in the request body, invalid fields, or other structural issues in the request.
401	Unauthorized	Returned when the request could not be authenticated (e.g. missing or invalid API key).
404	Not found	Returned when the requested resource does not exist.
429	Too many requests	Returned when you exceed the rate limit. Throttle requests and use the rate limit headers to retry appropriately.
500	Unexpected error	Returned when an unexpected problem occurs on our servers. Retry with exponential backoff.

Error object

Every error response uses the same structure: success set to false and a single error object with messageKey and message.

{
  "success": false,
  "error": {
    "messageKey": "contact_not_found",
    "message": "No contact could be found for this resource identifier. Please make sure to use the correct contact ID."
  }
}