> ## Documentation Index > Fetch the complete documentation index at: https://documentation.idenfy.com/llms.txt > Use this file to discover all available pages before exploring further. # Android SDK Face Authentication > Implement biometric face authentication in your Android app using the iDenfy SDK for fast 30-second returning user re-verification. Face Matching authentication works from Android SDK version 8.0.1. ## Introduction Face authentication is a tool to perform KYC checks once and then use the same scanRef to perform multiple verifications in just **30 seconds**. The flow only requires your user to take a regular face photo to perform the authentication. Face matching authentication ## Pre-Conditions A [successful verification](/kyc/generate-token#graphical-representation-of-token-generation-uml-activity) must be performed before initializing face authentication. For face authentication all you need is a scanRef, which is obtained during [session creation](/kyc/generate-token#receiving-response). ## Getting Started Follow the [iDenfy SDK integration guide](/sdks/android/quickstart), which is required for face authentication as well. After completing the steps and the application **compiles successfully**, you are ready to implement **face-auth specific** logic. You can also download **the sample app**, which supports face authentication. [Download here](https://github.com/idenfy/iDenfyResources/blob/main/sdk/android/tutorials/sample/idenfy_sample_android.zip). ### Handle Webhook Callback You will receive a webhook callback if it is your preferred way of handling results (recommended as it is more secure and reliable). The webhook structure is: ```json theme={"system"} { "token": "token", "clientId": "clientId", "scanRef": "scanRef", "status": "SUCCESS", "type": "AUTHENTICATION", "method": "FACE_MATCHING", "facePhoto": "https://s3.eu-west-1.amazonaws.com/production.users.storage/users_storage/users//FRONT.png?AWSAccessKeyId=&Signature=&Expires=" } ``` The `facePhoto` key is a String (URL), can be null, with a max length of 500. It provides a URL to download the selfie photo used for authentication. The `status` key has the following values: | Name | Description | | ---------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `SUCCESS` | The user completed face authentication flow and the authentication status, provided by an automated platform, is SUCCESS. | | `FAILED` | The user completed face authentication flow and the authentication status, provided by an automated platform, is FAILED. | | `CANCELED` | The user did not complete the face authentication flow and canceled it and the identification status, provided by an automated platform, is EXIT. | | `EXPIRED` | The user did not complete the face authentication flow, but did not cancel it explicitly and the identification status, provided by an automated platform, is EXPIRED. | To set your webhook URL, contact tech support via the [dashboard](https://admin.idenfy.com/auth/login). ### Handle Callback in SDK If you also want to handle results directly in the mobile app, implement the result handling in the SDK: ```Kotlin theme={"system"} private var identificationResultsCallback = registerForActivityResult( ActivityResultContracts.StartActivityForResult() ) { result: ActivityResult -> val resultCode = result.resultCode val data = result.data if (resultCode == IdenfyController.IDENFY_FACE_AUTHENTICATION_RESULT_CODE) { val faceAuthenticationResult: FaceAuthenticationResult = data!!.getParcelableExtra(IdenfyController.IDENFY_FACE_AUTHENTICATION_RESULT)!! Toast.makeText(this, "Face Authentication Status: " + faceAuthenticationResult.faceAuthenticationStatus.status, Toast.LENGTH_SHORT).show() when (faceAuthenticationResult.faceAuthenticationStatus) { FaceAuthenticationStatus.SUCCESS -> { // The user completed authentication flow, was successfully authenticated } FaceAuthenticationStatus.FAILED -> { // The user completed authentication flow, was not successfully authenticated } FaceAuthenticationStatus.EXIT -> { // The user did not complete authentication flow } } } } ``` ### Check Face Authentication Status and Create the Session Before initializing the SDK, check whether your user can use face authentication and obtain an authToken. See the [Create Face Auth Session](/face-authentication/token-generation) documentation. ### Initialize SDK Pass the session token to start face authentication: ```Kotlin theme={"system"} val faceAuthenticationInitialization = FaceAuthenticationInitialization(token) IdenfyController.getInstance().initializeFaceAuthenticationSDKV2(requireActivity(), (requireActivity() as BaseActivity).identificationResultsCallback, faceAuthenticationInitialization) ``` ## Customization ### Immediate Redirect You can pass an additional boolean to set the immediate redirect feature. This controls whether you **receive results immediately** from the SDK without any additional result pages. The user completes the verification, a loading state appears and closes -- without showing the final status screen. ```Kotlin theme={"system"} val faceAuthenticationInitialization = FaceAuthenticationInitialization(token, true) ``` ### Face Detection You can enable face detection, which requires users to place their face into the marked area before taking a photo. Face detection Contact tech support via the [Jira customer portal](https://idenfy-ivs.atlassian.net/servicedesk/customer/portal/1) to enable this feature. Face detection will apply to **both** KYC verification and face authentication flows. ### Passive Liveness Detection While using face matching authentication, you can enable passive liveness detection to detect whether a selfie photo is genuine or not. Contact tech support via the [Jira customer portal](https://idenfy-ivs.atlassian.net/servicedesk/customer/portal/1) to enable this feature. This will apply to **both** KYC verification and face authentication flows. ### Auto Capture You can enable auto capture, which requires users to place their face into the marked area. The picture is then automatically taken and immediately processed: Face authentication auto capture Contact tech support via the [Jira customer portal](https://idenfy-ivs.atlassian.net/servicedesk/customer/portal/1) to enable this feature for face authentication. ## UI Customization The UI can be customized the same as the [KYC verification flow](/sdks/android/ui-customization). Main [colors or styles](/sdks/android/ui-customization#customization-with-overriding-layouts-of-sdk) in the **styles.xml** or **colors.xml** files of your app target can be overridden, as well as the [layouts](/sdks/android/ui-customization#customization-with-overriding-layouts-of-sdk). Find colors, styles, and layouts in the [repository](https://github.com/idenfy/iDenfyResources/tree/main/sdk/android/). Face authentication flow has additional UI settings that can be passed using **IdenfyFaceAuthUIBuilder** along with **FaceAuthenticationInitialization**: ```kotlin theme={"system"} val idenfyFaceAuthUISettings = IdenfyFaceAuthUISettings.IdenfyFaceAuthUIBuilder() //Show or hide language selection button .withLanguageSelection(true) //Show or skip camera on boarding screen .withOnBoardingView(true) .build() val faceAuthenticationInitialization = FaceAuthenticationInitialization( token, idenfyFaceAuthUISettings = idenfyFaceAuthUISettings ) ``` ## Related topics - [iOS SDK Face Authentication](/sdks/ios/face-authentication.md) - [Android SDK Additional Features](/sdks/android/additional-features.md) - [Android SDK Migration Guide](/sdks/android/migration-guide.md) - [Face Authentication](/face-authentication/overview.md) - [Face Authentication in the Dashboard](/guides/dashboard/face-auth/face-authentication.md)