> For the complete documentation index, see [llms.txt](https://docs.vida.id/identity-stack/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.vida.id/identity-stack/verify/id-fraud-shield-sdk/integration-guide/web-sdk/backend-api-integration.md).

# Backend API Integration

Reference here - [API Reference | \[NEW\] VIDA Identity Stack](https://docs.vida.id/identity-stack/verify/id-fraud-shield-sdk/integration-guide/android/api-reference)

### Error Codes <a href="#error-codes" id="error-codes"></a>

The following error codes and messages will be returned from the Vida ID Fraud Shield SDK using the onError callback method, supplied by the hosting application.

#### Frontend Error Codes <a href="#frontend-error-codes" id="frontend-error-codes"></a>

| Code  | Message                                                                              | Description                                                                                           |
| ----- | ------------------------------------------------------------------------------------ | ----------------------------------------------------------------------------------------------------- |
| 40001 | "Unable to proceed, please check your connection"                                    | Indicates that the user's device is not connected to the internet.                                    |
| 40002 | "Unable to proceed due to network timeout, please check your connection"             | Indicates that the network request timed out, possibly due to a slow or unstable internet connection. |
| 40003 | "Unable to proceed, ensure authorization method is correct and token is not expired" | Indicates that the provided authorization token is invalid or has expired.                            |
| 50005 | "Unknown error occurred, please try again later"                                     | A general error indicating an unknown issue that requires further investigation.                      |
| 60003 | "Unknown error while generating hash"                                                | Indicates an issue occurred while generating a hash, typically during a secure operation.             |

#### Backend Error Codes <a href="#backend-error-codes" id="backend-error-codes"></a>

Reference here - [Error Codes | \[NEW\] VIDA Identity Stack](https://docs.vida.id/identity-stack/verify/id-fraud-shield-sdk/integration-guide/android/error-codes#vida-backend-error-codes)