# Error Handling

> Learn how to respond to errors in your API requests.

The Untether Labs API follows the [RFC-9457](https://www.rfc-editor.org/rfc/rfc9457.html)
Problem Detail specification for error responses. This standardized format provides consistent,
machine-readable error information to help you build robust applications.

A complete list of expected errors can be found in the [Error Reference](/errors).
Each endpoint in the API Reference documents the specific errors that it may return.

## Error Response Structure

All API errors return a JSON response with the following structure:

```json Error Response Structure icon=braces
{
    "type": "https://developers.untetherlabs.com/errors#user-not-found",
    "status": 404,
    "title": "A specified user does not exist in the system.",
    "detail": "User with ID '123e4567-e89b-12d3-a456-426614174000' was not found."
}
```

### Response Fields

Standard HTTP response codes are always returned in addition to the error body.

<ResponseField name='type' type='string' required>
    A URI that uniquely identifies the error type. Always use this field to identify and
    handle specific errors programmatically.
</ResponseField>
<ResponseField name='status' type='integer' required>
    The HTTP status code of the response (e.g., 400, 404, 500). This is always set in the
    actual HTTP response also.
</ResponseField>
<ResponseField name='title' type='string' required>
    A short, human-readable summary of the problem type.
</ResponseField>
<ResponseField name='detail' type='string'>
    A human-readable explanation specific to this occurrence of the problem.
</ResponseField>

<Note>
    Additional fields (extensions) may be present depending on the specific error type.
    See the response documentation for specific endpoints for details on any extensions.
</Note>

## Error Identification

Always use the `type` field to identify errors programmatically. The `type` contains the full URL path to the specific error documentation:

```javascript Error Identification Example icon=code
if (error.type === 'https://developers.untetherlabs.com/errors#user-not-found') {
    // Handle user not found
    console.log('User does not exist');
} else if (error.type === 'https://developers.untetherlabs.com/errors#validation') {
    // Handle validation error
    console.log('Input validation failed:', error.message);
}
```