Common API response codes and their meaning
Important
LUIS will be retired on October 1st 2025 and starting April 1st 2023 you will not be able to create new LUIS resources. We recommend migrating your LUIS applications to conversational language understanding to benefit from continued product support and multilingual capabilities.
The authoring and endpoint APIs return HTTP response codes. While response messages include information specific to a request, the HTTP response status code is general.
Common status codes
The following table lists some of the most common HTTP response status codes for the authoring and endpoint APIs:
| Code | API | Explanation |
|---|---|---|
| 400 | Authoring, Endpoint | request's parameters are incorrect meaning the required parameters are missing, malformed, or too large |
| 400 | Authoring, Endpoint | request's body is incorrect meaning the JSON is missing, malformed, or too large |
| 401 | Authoring | used endpoint key, instead of authoring key |
| 401 | Authoring, Endpoint | invalid, malformed, or empty key |
| 401 | Authoring, Endpoint | key doesn't match region |
| 401 | Authoring | you are not the owner or collaborator |
| 401 | Authoring | invalid order of API calls |
| 403 | Authoring, Endpoint | total monthly key quota limit exceeded |
| 409 | Endpoint | application is still loading |
| 410 | Endpoint | application needs to be retrained and republished |
| 414 | Endpoint | query exceeds maximum character limit |
| 429 | Authoring, Endpoint | Rate limit is exceeded (requests/second) |