A production-grade biometric authentication SDK designed for apps that demand trust.
Ideal for fintech, banking, e-wallets, secure messaging, parental control, or any app requiring identity protection and transaction-level security.
This SDK simplifies AndroidX biometric integration with modern Kotlin practices, supporting:
- Fingerprint
- Face Unlock
- Device Credential fallback (PIN/Pattern/Password)
- ✅ Seamless integration with AndroidX Biometric APIs
- ✅ Supports Fingerprint, Face, and Device Credential fallback
- ✅ Designed for fintech, banking, and high-trust apps
- ✅
NOT_ENABLED,ENABLED_AND_MANDATORY,ENABLED_BUT_NOT_MANDATORYauth modes - ✅ Lifecycle-safe: no biometric prompts while app is backgrounded
- ✅ Clean Kotlin interfaces — easy to test with MockK
- ✅ Pluggable, SDK-ready structure — ideal for JitPack/Maven distribution
Use this SDK directly in your Android project using JitPack.
In your root-level settings.gradle.kts:
dependencyResolutionManagement { repositories { maven { url = uri("https://jitpack.io") } } }In your module-level build.gradle.kts:
implementation("com.github.NoNCoderF:biometric-sdk:v1.0.3")This SDK offers two flexible integration modes depending on your product's security needs:
Best for apps that want to secure specific features like viewing a profile, accessing settings, or opening sensitive notes.
Biometric is triggered manually when the user takes a high-trust action.
private val biometricAuthenticator: BiometricAuthenticator by lazy { val biometricManager = MyBiometricManagerImpl( this, //AppCompatActivity "Unlock", "Unlock to use the app" ) BiometricAuthenticatorImpl( biometricManager, object : BiometricAuthenticatorCallback{ override fun onBiometricSuccess() { //onSuccess } override fun onBiometricFailure(errorCode: Int, errString: CharSequence) { //onFailure } } ) } private val biometricAuthHandler: BiometricAuthHandler by lazy { BiometricAuthHandler( biometricAuthenticator = biometricAuthenticator, requirement = { AuthenticationRequirement.ENABLED_AND_MANDATORY }, bypass = { false }, ) } //On user action // Evaluate biometric flow dynamically fun onClick() { //Reset the prompt controller BiometricPromptController.resetBiometricFlag() when (biometricAuthHandler.evaluate()) { BiometricDecision.BYPASS -> { // Biometric is turned off or bypassed manually } BiometricDecision.SECURITY_NOT_PRESENT -> { // Device doesn't support biometric OR no credential fallback } BiometricDecision.SETUP_REQUIRED -> { // Biometric is supported but user hasn't enrolled — suggest settings intent } BiometricDecision.AUTHENTICATE -> { biometricAuthenticator.authenticate() } } } Use this when your app needs biometric protection for every screen or session, like banking apps, parental control, or work-profile locked apps.
Biometric prompts auto-trigger as the user navigates the app.
In your Application or base Activity:
override fun onCreate() { super.onCreate() ProcessLifecycleOwner.get().lifecycle.addObserver(AppVisibilityTracker) }abstract class BaseBiometricActivity : AppCompatActivity() { private val biometricAuthenticator: BiometricAuthenticator by lazy { val biometricManager = MyBiometricManagerImpl( this, //AppCompatActivity "Unlock", "Unlock to use the app" ) BiometricAuthenticatorImpl( biometricManager, object : BiometricAuthenticatorCallback{ override fun onBiometricSuccess() { //onSuccess } override fun onBiometricFailure(errorCode: Int, errString: CharSequence) { //onFailure } } ) } private val biometricAuthHandler: BiometricAuthHandler by lazy { BiometricAuthHandler( biometricAuthenticator = biometricAuthenticator, requirement = { AuthenticationRequirement.ENABLED_AND_MANDATORY }, bypass = { false }, ) } override fun onResume() { super.onResume() // Evaluate biometric flow dynamically when (biometricAuthHandler.evaluate()) { BiometricDecision.BYPASS -> { // Biometric is turned off or bypassed manually } BiometricDecision.PROMPT_SKIPPED -> { // App in foreground, biometric not required in this state } BiometricDecision.SECURITY_NOT_PRESENT -> { // Device doesn't support biometric OR no credential fallback } BiometricDecision.SETUP_REQUIRED -> { // Biometric is supported but user hasn't enrolled — suggest settings intent } BiometricDecision.AUTHENTICATE -> { biometricAuthenticator.authenticate() } } } }Then extend it across your app:
class DashboardActivity : BaseBiometricActivity()| Use Case | Recommended Mode |
|---|---|
| Secure a settings/profile page | 🔐 Identity Protection (Mode 1) |
| Authenticate before money transfer | 💳 Transaction-Level (Mode 2) |
| Lock every screen or session | 💳 Transaction-Level (Mode 2) |
💡 Use one mode or both — the SDK adapts to your product’s security needs.
- 🔍 Built for testability using dependency injection
- ✅ Easily mock
BiometricAuthenticatorwith MockK - 🧼
AppVisibilityTrackeris stateless and safe to test
MIT License — free for commercial and non-commercial use.
Just give credit where it’s due ❤️
Built with ❤️ by Nizamuddin Ahmed
Contributions, issues, and stars are always welcome ⭐