# @ohos.userIAM.faceAuth (Facial Authentication)

The **userIAM.faceAuth** module provides APIs for face enrollment.

> **NOTE**
>
> The initial APIs of this module are supported since API version 9. Newly added APIs will be marked with a superscript to indicate their earliest API version.
>
> The APIs provided by this module are system APIs.

## Modules to Import

```js
import userIAM_faceAuth from '@ohos.userIAM.faceAuth';
```

## FaceAuthManager

Provides APIs for facial authentication management.

### constructor

constructor()

A constructor used to create a **FaceAuthManager** object.

**System capability**: SystemCapability.UserIAM.UserAuth.FaceAuth

**Return value**

| Type                  | Description                |
| ---------------------- | -------------------- |
| [FaceAuthManager](#faceauthmanager) | **FaceAuthManager** object.|

**Example**

```js
import userIAM_faceAuth from '@ohos.userIAM.faceAuth';

let faceAuthManager = new userIAM_faceAuth.FaceAuthManager();
```

### setSurfaceId

setSurfaceId(surfaceId: string): void;

Sets an [XComponent surface ID](../arkui-ts/ts-basic-components-xcomponent.md#getxcomponentsurfaceid) for the face preview page in the face enrollment process. This API must be used with [AddCredential](./js-apis-osAccount.md#addcredential8).

**System capability**: SystemCapability.UserIAM.UserAuth.FaceAuth

**Required permissions**: ohos.permission.MANAGE_USER_IDM

**Parameters**

| Name        | Type                              | Mandatory| Description                      |
| -------------- | ---------------------------------- | ---- | -------------------------- |
| surfaceId       | string     | Yes  | ID of the surface held by the [XComponent](../arkui-ts/ts-basic-components-xcomponent.md#getxcomponentsurfaceid).|

For details about the following error codes, see [User Authentication Error Codes](../errorcodes/errorcode-useriam.md).

**Error codes**

| ID| Error Message|
| -------- | ------- |
| 201 | Permission verification failed. |
| 202 | The caller is not a system application. |
| 12700001 | The operation is failed. |

**Example**

```js
import userIAM_faceAuth from '@ohos.userIAM.faceAuth';

// The surfaceId is obtained from the XComponent control. The surfaceId here is only an example.
let surfaceId = "123456";
let manager = new userIAM_faceAuth.FaceAuthManager();
try {
    manager.setSurfaceId(surfaceId);
    console.info("Set the surface ID successfully");
} catch (e) {
    console.error("Failed to set the surface ID, error = " + e);
}
```