# Questions on error codes
[Server-side error codes](https://open.feishu.cn/document/ukTMukTMukTM/ugjM14COyUjL4ITN) lists the common server-side API error codes and suggestions on troubleshooting the errors.

**1. I encountered an error code that is not listed in the Open Platform documentation. What should I do?**

Answer: We're sorry for the inconvenience. You can [contact our customer service](https://applink.feishu.cn/client/helpdesk/open?id=6626260912531570952&extra=%7B%22channel%22%3A14%2C%22created_at%22%3A1614493146%2C%22scenario_id%22%3A6885151765134622721%2C%22signature%22%3A%22ca94c408b966dc1de2083e5bbcd418294c146e98%22%7D). We will add description for the error code shortly.

You can also click your profile photo in the upper left corner of Feishu, and select **Contact Us** for support.
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**2. Why did I receive the error code 20007 when using the authentication API [obtain user identity](https://open.feishu.cn/document/uAjLw4CM/ukTMukTMukTM/reference/authen-v1/authen/refresh_access_token)?**

Answer:
- If the [obtain user identity API](https://open.feishu.cn/document/uAjLw4CM/ukTMukTMukTM/reference/authen-v1/authen/refresh_access_token) returns the error code 1007 or 20007, it indicates that the code is invalid. Ensure that the code is not consumed repeatedly or expired (the code is valid for 5 minutes and can only be used once).
- The code obtained by calling the gadget API tt.login() cannot be used in the server-side API for obtaining user information.

**3. Why are there multiple error codes for the same type of error?**

Answer: Different business domains and different API versions may cause some of the same type of errors to return different error codes.

For example:

- When the message API is frequency-limited, the error code 230020 will be returned; when the message flow API is frequency-limited, the error code 99991400 will be returned.
- When the message flow API returns the error code 99991400, the HTTP Code (status code) is 429, but in the historical version of the API, the HTTP Code corresponding to the error code 99991400 is 400.

Based on the above situation, please do not use the same error code and the same HTTP Code to intercept all API errors encountered in the actual development process. You need to pay attention to handling problems according to the actual error information of different APIs when calling the API. For detailed descriptions of error codes, please refer to the API documentation or [Common Error Codes](https://open.feishu.cn/document/ukTMukTMukTM/ugjM14COyUjL4ITN).