🛡️ kavach_flutter

Dart SDK for the Kavach Shield Engine

🔗 Source Code: Rajeev02/kavachid on GitHub

📖 Overview

The official Kavach Flutter SDK. It provides cross-platform biometric authentication by securely bridging down to native iOS FaceID and Android Biometrics through highly optimized Dart platform channels.

✨ Key Features

  • Write Once, Authenticate Anywhere: A single Dart API call triggers the correct native UI on both iOS and Android.
  • Platform Channel Optimization: Extremely low latency communication between Dart and native layers.
  • Secure Storage Wrapper: Includes a built-in wrapper for flutter_secure_storage to ensure session tokens are never stored in plain text.
  • Device Fingerprinting: Extracts underlying device hardware IDs for risk-engine evaluation.

🏆 Why Use This Library?

  • Saves Development Time: Eliminates the need to write custom Swift and Kotlin bridging code for authentication.
  • Type Safety: 100% null-safe Dart code with strong typing for all API responses.
  • Consistent UX: Ensures your users see the OS-standard biometric prompts they trust, rather than custom UI dialogs.

🚀 Installation (Pub.dev)

Add to your pubspec.yaml:

dependencies:
  kavach_flutter: ^1.0.1

💻 Detailed Usage

1. Initialization

import 'package:kavach_flutter/kavach_flutter.dart';

// Initialize the singleton client
final kavach = KavachClient(
  serverUrl: 'https://api.yourdomain.com',
  enableTelemetry: true // Sends device fingerprints for risk analysis
);

2. Authenticating

Future<void> handleLogin() async {
  // Check if hardware is present and enrolled
  final canCheckBiometrics = await kavach.canCheckBiometrics;
  
  if (canCheckBiometrics) {
    try {
      final sessionToken = await kavach.loginWithBiometrics(
        email: 'user@example.com',
        localizedReason: 'Please authenticate to access your secure vault.',
      );
      print('Authentication successful: $sessionToken');
    } catch (e) {
      print('Authentication failed: $e');
    }
  } else {
    print('Device does not support biometrics. Fallback to PIN.');
  }
}

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