biometric_shield library

BiometricShield — A composable Flutter SDK for biometric authentication.

Core package for biometric authentication. Pure Dart business logic without Flutter widget dependencies.

For Flutter UI widgets, import biometric_shield_ui separately.

Classes

BiometricCancelled
User explicitly cancelled authentication.
BiometricCapability
Rich capability model describing what biometric features are available on the current device.
BiometricConfig
Configuration object for the BiometricShield SDK.
BiometricError
An unexpected platform error occurred.
BiometricEvent
An audit event emitted by the BiometricShield SDK.
BiometricFallbackSuccess
Biometric failed but a fallback succeeded.
BiometricInvalidated
Biometric keys were invalidated (new fingerprint enrolled etc).
BiometricLockedOut
Max attempts exceeded. User is locked out.
BiometricPolicy
Server-driven policy overrides.
BiometricPreferences
User-facing biometric preferences that can be changed at runtime.
BiometricReauthenticationRequired
Token refresh failed and the user must re-authenticate from scratch.
BiometricResult
Sealed result type for all biometric authentication outcomes.
BiometricSession
Represents an active biometric authentication session.
BiometricSessionValid
Active session was found — no prompt shown.
BiometricShield
Main entry point for the BiometricShield SDK.
BiometricShieldInterface
Contract for BiometricShield that enables proper dependency injection and mock substitution in tests.
BiometricShieldMockBase
Base class for mock implementations used in testing.
BiometricSuccess
Biometric auth succeeded. Session is now active.
BiometricTokenExpired
Auth succeeded but token was expired or missing.
BiometricUnavailable
Biometric is not available or not enrolled on this device.
FallbackHandler
Interface for handling fallback authentication UI.
LockoutState
Represents the current lockout state for a user.
PolicyProvider
Interface for server-driven policy enforcement.
TokenLifecycle
Interface for backend-agnostic token lifecycle management.
TokenRefreshFailed
Refresh failed due to a transient error.
TokenRefreshReauthRequired
The refresh token itself is expired; full re-auth needed.
TokenRefreshResult
Result of a token refresh attempt.
TokenRefreshSuccess
Refresh succeeded.
TokenStoreInterface
Interface for custom secure token storage.

Enums

BiometricAuthMethod
The authentication method used to establish a session.
BiometricEventType
All event types emitted by the BiometricShield SDK.
BiometricFallback
Available fallback authentication methods when biometric auth fails or is unavailable.
BiometricUnavailableReason
Reason why biometric authentication is unavailable on this device.
FallbackResult
Result of a fallback attempt.
TokenStatus
Status of a stored token after validation.