> For the complete documentation index, see [llms.txt](https://docs.copperx.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.copperx.io/error-handling-and-troubleshooting.md).

# Error Handling & Troubleshooting

| Status Code | Meaning               | Common Cause             |
| ----------- | --------------------- | ------------------------ |
| 400         | Bad Request           | Invalid data in request  |
| 401         | Unauthorized          | Invalid API Key          |
| 403         | Forbidden             | Access denied            |
| 404         | Resource not found    | Incorrect ID or endpoint |
| 500         | Internal Server Error | Copperx service error    |

**Tips:**

* Use test environment first.
* Check API logs for request/response details.
* Contact support if you face persistent issues.