Expo purchase verification

// Install react-native-iap (with dev client / EAS Build)
npx expo install react-native-iap

// Then rebuild with:
npx expo run:android  # or run:ios

// In your Expo app
import RNIap, { PurchaseError } from 'react-native-iap';

// After purchase completes, send token to your backend
const handlePurchase = async (purchase: Purchase) => {
  const result = await fetch('https://your-api.com/verify', {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({
      platform: Platform.OS,
      purchaseToken: purchase.transactionReceipt,
      productId: purchase.productId,
      packageName: 'com.yourapp',
    }),
  });
  await RNIap.finishTransaction({ purchase, isConsumable: false });
  return result.json();
};

// Your backend (Node.js example)
app.post('/verify', async (req, res) => {
  const { platform, purchaseToken, productId, userId } = req.body;

  const endpoint = platform === 'android'
    ? '/v1/purchases/google-play/verify'
    : '/v1/purchases/apple/verify';

  const verification = await fetch(
    `https://tierux.com/api${endpoint}`,
    {
      method: 'POST',
      headers: {
        'Authorization': 'Bearer YOUR_API_KEY',
        'Content-Type': 'application/json',
      },
      body: JSON.stringify({
        appId: 'app_123',
        userId,
        packageName: 'com.yourapp',
        productId,
        purchaseToken,
      }),
    }
  );

  const data = await verification.json();
  res.json({ active: data.active, entitlement: data.entitlement });
});

// In your Expo app — gate premium features
const { active, entitlement } = await result.json();

if (active) {
  // Show premium content
  return ;
}

// Show paywall or limited content
return ;