React Native SDK

Complete SDK for content registration with Starknet wallet management

Installation

iOS Setup

Android Setup

Add Play Integrity API to android/app/build.gradle:

dependencies {
    implementation 'com.google.android.play:integrity:1.3.0'
}

Then create the Play Integrity native module. See the full Android setup guide.

API Reference

BlockFactProvider

Wrap your app with this provider:

import { BlockFactProvider } from '@blockfact/react-native-facti-pro';

<BlockFactProvider>
  <App />
</BlockFactProvider>

useBlockFact()

Hook to access BlockFact functionality:

const {
  wallet,           // Current wallet object
  loading,          // Loading state
  error,            // Error message
  createWallet,     // Function to create wallet
  registerContent,  // Function to register content
  deleteWallet,     // Function to delete wallet
  hasWallet         // Boolean: wallet exists
} = useBlockFact();

createWallet()

Creates a new Starknet wallet with biometric protection:

const wallet = await createWallet();
// Returns: { address, publicKey, privateKey }

registerContent()

Registers content on blockchain:

const result = await registerContent({
  imageUri: string,           // Required: Image URI
  latitude: number,           // Required: GPS latitude
  longitude: number,          // Required: GPS longitude
  exifData: object,          // Required: Camera EXIF data
  captureTimestamp: string,  // Required: ISO timestamp
  metadata: object           // Optional: Additional metadata
});

// Returns:
{
  factiUrl: string,    // IPFS URL to .facti file
  factiCid: string,    // IPFS CID
  txHash: string,      // Blockchain transaction hash
  sessionId: string    // Session ID for tracking
}

Complete Example

import React from 'react';
import { View, Button, Text } from 'react-native';
import { useBlockFact } from '@blockfact/react-native-facti-pro';
import * as ImagePicker from 'expo-image-picker';
import * as Location from 'expo-location';

function CameraScreen() {
  const { wallet, createWallet, registerContent, hasWallet } = useBlockFact();

  // 1. Create wallet if needed
  if (!hasWallet) {
    return <Button title="Create Wallet" onPress={createWallet} />;
  }

  // 2. Capture and register
  const handleCapture = async () => {
    // Get location
    const location = await Location.getCurrentPositionAsync();

    // Take photo
    const photo = await ImagePicker.launchCameraAsync({
      exif: true,
      quality: 1
    });

    // Register on blockchain
    const result = await registerContent({
      imageUri: photo.uri,
      latitude: location.coords.latitude,
      longitude: location.coords.longitude,
      exifData: photo.exif,
      captureTimestamp: new Date().toISOString()
    });

    console.log('Registered:', result.factiUrl);
  };

  return (
    <View>
      <Text>Wallet: {wallet.address}</Text>
      <Button title="Take Photo" onPress={handleCapture} />
    </View>
  );
}

Security Features

• ✅ Proper Starknet key generation using starknet.js
• ✅ Biometric authentication (Face ID, Touch ID, Fingerprint)
• ✅ 30-second image freshness window
• ✅ Device attestation (iOS DeviceCheck, Android Play Integrity)
• ✅ EXIF validation required
• ✅ No insecure fallbacks

Troubleshooting

Error: DeviceCheck not available

You need to implement the iOS DeviceCheck native module. See the iOS setup guide.

Error: Image too old

Images must be registered within 30 seconds of capture. Call registerContent() immediately after taking the photo.

Error: EXIF data required

Make sure to enable EXIF data when capturing: { exif: true }