> ## Documentation Index
> Fetch the complete documentation index at: https://cobo-docs-feature-cobo-cli.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Error codes and status codes

This article explains the common error codes and HTTP status codes you may encounter when using the Cobo WaaS 2.0 API and how to resolve the errors.

### Error codes

| **Error code** | **Description**                                           | **Solution**                                                                                                                                                                                                                        |
| -------------- | --------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| 2000           | Internal error.                                           | Try again later.                                                                                                                                                                                                                    |
| 2002           | Unsupported HTTP method.                                  | Use a supported HTTP method.                                                                                                                                                                                                        |
| 2003           | Missing required parameters.                              | Provide the required parameters.                                                                                                                                                                                                    |
| 2006           | Illegal parameter format or value.                        | Provide valid parameters.                                                                                                                                                                                                           |
| 2010           | Rate limit exceeded.                                      | Try again later.                                                                                                                                                                                                                    |
| 2021           | Missing request handler.                                  | Provide required handlers.                                                                                                                                                                                                          |
| 2022           | Missing required request headers.                         | Provide required headers.                                                                                                                                                                                                           |
| 2023           | API signature validation failed.                          | Use a valid API signature.                                                                                                                                                                                                          |
| 2024           | API key authentication failed.                            | Use a valid API key. If your API key is permanent, you also need to send the API request from a whitelisted IP address. See [Register an API key](https://manuals.cobo.com/en/portal/developer-console/create-api-key) for details. |
| 2025           | Forbidden access to resources.                            | Check the permission of your API key.                                                                                                                                                                                               |
| 2026           | Too many requests.                                        | Try again later.                                                                                                                                                                                                                    |
| 2028           | Resource not found.                                       | Check the request URL.                                                                                                                                                                                                              |
| 2029           | Invalid status property.                                  | Check the value of the status property.                                                                                                                                                                                             |
| 2040           | Duplicate key.                                            | Use a unique key.                                                                                                                                                                                                                   |
| 2050           | No available pricing plan or the usage limit is exceeded. | Purchase a pricing plan or upgrade an existing one. To learn more about pricing plans, see [Introduction to Bills & Payments](https://manuals.cobo.com/en/portal/bills-and-payments/introduction).                                  |

### HTTP status codes

| **Status code** | **Description**        | **Solution**                                    |
| --------------- | ---------------------- | ----------------------------------------------- |
| 200             | OK.                    | N/A                                             |
| 400             | Bad request.           | Check the request parameters.                   |
| 401             | Unauthorized.          | Check the API key, API signature, or timestamp. |
| 403             | Forbidden.             | Ensure you have the required permissions.       |
| 404             | Not Found.             | Check the requestURL.                           |
| 405             | Method Not Allowed.    | Use a supported HTTP method.                    |
| 406             | Not Acceptable.        | Ensure the request content format is JSON.      |
| 429             | Too Many Requests.     | Reduce request frequency and try again later.   |
| 500             | Internal Server Error. | Try again later.                                |
| 502             | Bad Gateway.           | Check the connectivity and try again later.     |
| 503             | Service Unavailable.   | Try again later.                                |