> ## Documentation Index
> Fetch the complete documentation index at: https://docs.blinkops.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Run Second Factor Authentication

Perform second-factor authentication for a user.

> [!NOTE]
>
> External Documentation
>
> To learn more, visit the [Duo Auth documentation](https://duo.com/docs/authapi#/auth).

## Basic Parameters

| Parameter | Description |
| - | - |
| Async | Determine whether to execute the action asynchronously.  If set to `1`, the action will return a `transaction ID`, which later can be used with the `Get Auth Status` action. If this parameter is not provided, or set to **0**, the action will only return a response once authentication is complete. |
| Device | ID of the device to authentication by. This device must have the capability of the corresponding factor. To obtain the device ID and verify it's capabilities, you can use the `Run Preauth` action and check the specific device's information. |
| Display Username | String to display in Duo Mobile in place of the user's Duo username. |
| Factor | Factor to use for authentication. For more information on each factor, please visit [Duo's documentation](https://duo.com/docs/authapi#/auth).  `Note:` To use the different factors you must enable them in the applied policy. Check our [Duo Auth documentation](https://docs.blinkops.com/docs/integrations/duo-auth.md) for further information. |
| Passcode | Passcode entered by the user. |
| Push Info | A set of URL-encoded key/value pairs with additional contextual information associated with this authentication attempt. The Duo Mobile app will display this information to the user.  **Note**, The URL-encoded string's total length must be less than 20,000 bytes. |
| Push Notification | The string that displays in the Duo Mobile app push notification and UI. |
| Transaction ID | The transaction ID received in the `Run Preauth` action response when the request specified `Client Supports Verified Push`= 1 for `Verified Duo Push`. |
| User ID | The unique identifier for the user as generated by `Duo` upon user creation.  Can be obtained by the `List Users` action in the Duo collection. `Important To Note:` The `Duo` collection has a separate connection that requires Admin API Credentials. Please follow [our Duo documentation](https://docs.blinkops.com/docs/integrations/duo.md) to obtain them. |
| User Info Type | Choose the user's information to provide. You must specify either the user ID or the username. |
| Username | The Unique username that is commonly specified during user creation. This value may also represent a username alias assigned to a user.  Can be obtained by the `List Users` action in the Duo collection. `Important To Note:` The `Duo` collection has a separate connection that requires Admin API Credentials. Please follow [our Duo documentation](https://docs.blinkops.com/docs/integrations/duo.md) to obtain them. |

## Advanced Parameters

| Parameter | Description |
| - | - |
| Hostname | The host name of the device accessing the application. |
| IP Address | The IP address of the user to be authenticated.  If an Auth API client does not send the ipaddr value in a request, policy settings based on available IP address information, like authorized networks or user location have no effect. |

## Example Output

```json theme={"dark"}
{
	"stat": "OK",
	"response": {
		"result": "allow",
		"status": "allow",
		"status_msg": "Success. Logging you in..."
	}
}
```