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Payment Implementation

Learn how to implement subscription payments in your a0 app using the a0-purchases library.
The a0 payment system uses the a0-purchases library. All apps built with a0 come with the necessary configuration and providers built in.

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Prerequisites

Before implementing payments in your code, ensure you have:
1

Completed Payment Setup

Created your features, plans, and offerings in the a0 dashboard. See the Payment Setup guide.
2

Synced to Providers

Synced your plans to Stripe and/or Apple App Store Connect.
3

Created Offerings

Created at least one offering and set it as current - this is required for paywalls to display products.

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Building a Paywall

Here’s a simple paywall component using the useA0Purchases hook: 
import { useA0Purchases } from 'a0-purchases';

function PaywallScreen() {
  const { 
    isPremium, 
    isLoading,
    offerings,
    purchase,
    restore,
  } = useA0Purchases();

  // Get packages from offerings - REQUIRED for paywall to work
  const packages = offerings?.all?.[0]?.availablePackages || [];

  const handlePurchase = async (packageId) => {
    try {
      await purchase(packageId);
      if (isPremium) {
        // Success! Navigate to premium content
      }
    } catch (error) {
      if (!error.userCancelled) {
        // Show error to user
      }
    }
  };

  if (isLoading) {
    return <ActivityIndicator />;
  }

  if (packages.length === 0) {
    return <Text>No products available</Text>;
  }

  return (
    <View>
      {packages.map((pkg) => (
        <TouchableOpacity
          key={pkg.identifier}
          onPress={() => handlePurchase(pkg.identifier)}
        >
          <Text>{pkg.product.title}</Text>
          <Text>{pkg.product.priceString}</Text>
          <Text>
            {pkg.packageType === 'WEEKLY' ? 'per week' : 
             pkg.packageType === 'MONTHLY' ? 'per month' : 
             pkg.packageType === 'ANNUAL' ? 'per year' : ''}
          </Text>
        </TouchableOpacity>
      ))}
      
      <Button title="Restore Purchases" onPress={restore} />
    </View>
  );
}
Your paywall will show no products if you haven’t created offerings. Offerings are REQUIRED for the paywall to work.

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Checking Premium Status

The simplest way to gate content is using the isPremium property: 
function PremiumContent() {
  const { isPremium } = useA0Purchases();
  
  if (!isPremium) {
    return <PaywallScreen />;
  }
  
  return <YourPremiumContent />;
}

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Checking Specific Entitlements

isPremium returns true if the user has ANY active entitlement. If you have multiple features/entitlements and need to check specific ones, use getCustomerInfo().
function FeatureGatedContent() {
  const { getCustomerInfo } = useA0Purchases();
  const customerInfo = getCustomerInfo();
  
  // Check for specific entitlements
  const hasProFeature = customerInfo?.entitlements.active['PRO'];
  const hasAdFree = customerInfo?.entitlements.active['AD_FREE'];
  const hasUnlimitedStorage = customerInfo?.entitlements.active['UNLIMITED_STORAGE'];
  
  return (
    <View>
      {hasProFeature && <ProContent />}
      {hasAdFree ? <ContentWithoutAds /> : <ContentWithAds />}
      {hasUnlimitedStorage && <UnlimitedUploadButton />}
    </View>
  );
}

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Advanced Implementation

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Custom Paywall with Package Details

function DetailedPaywallScreen() {
  const { offerings, purchase, isPremium } = useA0Purchases();
  const currentOffering = offerings?.current;
  
  if (!currentOffering) {
    return <Text>Loading products...</Text>;
  }
  
  // Get different package types
  const weeklyPackage = currentOffering.weekly;
  const monthlyPackage = currentOffering.monthly;
  const annualPackage = currentOffering.annual;
  
  return (
    <View>
      <Text>Choose your plan:</Text>
      
      {weeklyPackage && (
        <PlanOption 
          package={weeklyPackage}
          onPress={() => purchase(weeklyPackage.identifier)}
        />
      )}
      
      {monthlyPackage && (
        <PlanOption 
          package={monthlyPackage}
          onPress={() => purchase(monthlyPackage.identifier)}
          highlighted={true} // Most popular
        />
      )}
      
      {annualPackage && (
        <PlanOption 
          package={annualPackage}
          onPress={() => purchase(annualPackage.identifier)}
          savings="Save 25%"
        />
      )}
    </View>
  );
}

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Handling Purchase States

function PurchaseButton({ packageId }) {
  const { purchase } = useA0Purchases();
  const [isPurchasing, setIsPurchasing] = useState(false);
  const [error, setError] = useState(null);
  
  const handlePurchase = async () => {
    setIsPurchasing(true);
    setError(null);
    
    try {
      const result = await purchase(packageId);
      // Success - the hook will update isPremium automatically
      navigation.navigate('Success');
    } catch (err) {
      if (err.userCancelled) {
        // User cancelled - no need to show error
      } else if (err.code === 'PRODUCT_ALREADY_PURCHASED') {
        // User already has this product
        setError('You already have an active subscription');
      } else {
        // Other error
        setError('Purchase failed. Please try again.');
      }
    } finally {
      setIsPurchasing(false);
    }
  };
  
  return (
    <>
      <Button 
        title="Subscribe Now"
        onPress={handlePurchase}
        disabled={isPurchasing}
      />
      {error && <Text style={{ color: 'red' }}>{error}</Text>}
    </>
  );
}

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Testing Purchases

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Test Credentials

Stripe Test Cards:
  • Success: 4242 4242 4242 4242
  • Decline: 4000 0000 0000 0002
  • More test cards in Stripe docs
Apple Sandbox:
  • Use App Store Connect sandbox tester accounts
  • Subscriptions auto-renew every few minutes for testing
  • Clear purchase history in Settings → App Store → Sandbox Account

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Testing Flow

1

Enable Test Mode

For Stripe, ensure you synced to the sandbox environment in your payment setup.
2

Test Purchase Flow

Make test purchases using the test credentials above.
3

Verify Entitlements

Check that isPremium updates correctly and specific entitlements are active.
4

Test Restore

Clear app data and test the restore purchases functionality.

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Troubleshooting

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Next Steps

a0-purchases API Reference

Complete library documentation with all available methods and properties.

Test on Real Devices

Build and test payment flows on physical devices.