> For AI agents: the complete documentation index is available at /llms.txt, the full documentation bundle is available at /llms-full.txt.

# ErrorResponse

Error response object based on RFC 7807 Problem Details for HTTP APIs.
See [https://datatracker.ietf.org/doc/html/rfc7807](https://datatracker.ietf.org/doc/html/rfc7807) for details.

**Response Format:** A response is either in the new RFC 7807 Problem Details format OR the legacy Message format, but never both.

- **New Format (RFC 7807):** Contains the `type` property and standard problem detail properties (`title`, `detail`, `status`). May also include additional extension members.
- **Legacy Format:** Contains only the `Message` property. This format is used for some existing error responses during our transition to full RFC 7807 compliance.

**Usage:** Check if the `type` property is present. If it exists, the response is in RFC 7807 format. If `type` is absent, fall back to reading the `Message` property.

#### Properties

| Name         | Type    | Description                                                                                                                                                                                                                                                                                       |
| ------------ | ------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **type**     | String  | <p>A URI reference identifying the problem type. This property is always present in RFC 7807 responses.</p>                                                                                                                                                                                       |
| **title**    | String  | <p>A short, human-readable summary of the problem</p>                                                                                                                                                                                                                                             |
| **detail**   | String  | <p>A human-readable explanation specific to this occurrence of the problem</p>                                                                                                                                                                                                                    |
| **status**   | Integer | <p>The HTTP status code</p>                                                                                                                                                                                                                                                                       |
| **instance** | String  | <p>A URI reference that identifies the specific occurrence of the problem</p>                                                                                                                                                                                                                     |
| **Message**  | String  | <p><strong>Deprecated (Legacy Format Only):</strong> Contains the error message in the old response format. This property appears alone in legacy error responses and is mutually exclusive with the RFC 7807 properties above. Will be phased out as we complete our transition to RFC 7807.</p> |

**Examples:**

_Modern RFC 7807 Problem Details format_

```json
{
  "type": "https://api.signhost.com/errors/validation-failed",
  "title": "Validation Failed",
  "detail": "One or more validation errors occurred",
  "status": 400,
  "errors": {
    "$": [
      "Some validation error"
    ]
  }
}
```

_Legacy error response format_

```json
{
  "Message": "An error occurred while processing the request."
}
```