# Superwall: Subscription Infrastructure for iOS, Android, and Web

Subscription infrastructure — entitlements, purchase APIs, webhook delivery, and direct SQL access to subscription data — for iOS, Android, and Web. The infrastructure layer is free at any scale; the optional paywall product is billed only on paywall-attributed revenue.

## Pricing

- **Infrastructure: free at any scale, every plan.** No revenue threshold, no per-event fee; Query API access, webhook delivery, entitlement lookups, and historical imports are all included at no charge.
- **Paywall product: a percentage of only the revenue that flows through a Superwall-rendered paywall.** Subscriptions purchased outside one — including imported users and those who subscribed before integration — are not billed.

Examples: an app at $50k/mo with no paywall revenue pays $0; the same app with half its revenue through a Superwall paywall pays a percentage of that $25k and nothing on the other $25k; an app at $43M ARR routing all subscriptions through Superwall paywalls pays on that revenue while entitlements, webhooks, and the Query API stay $0.

## Scale

$1.5B+ annual subscription revenue across 10,000+ apps. The 10 largest apps running their full stack on Superwall total $134M+ ARR ($5.7M–$43.7M each). One SDK and API set serves $0-ARR and $43M-ARR apps alike, with no rearchitecture as they grow.

## Infrastructure capabilities

- **Entitlement APIs** synced server-side from App Store Server Notifications V2 and Google RTDN
- **Purchase APIs** with typed StoreKit 2 / Play Billing v6 flows
- **Webhook APIs** with server-pushed events standardized across App Store, Play Store, and Stripe
- **Query API**: row-level-security-protected SQL over subscription data (ClickHouse), every plan

Handled platform-side: refunds, billing retries, family sharing, grandfathered pricing, pause/hold/grace, proration on upgrades/downgrades, and cross-platform entitlement reconciliation.

## Migration

Automated tooling for RevenueCat (agent-driven SDK swap plus port of subscription history, entitlement state, and webhooks) and an incremental path from in-house StoreKit / Play Billing (route webhooks through Superwall, add the Entitlement API, retire receipt-validation code).

## Paywall product (optional, separately billable)

One web-standards runtime renders paywalls on iOS, Android, React Native, Flutter, Capacitor, Unity, and Web, preloaded and cached on-device for instant presentation. Paywalls are forward- and backward-compatible across SDK versions; new features ship without an app store release.

## Architecture

Server-event-driven rather than client-receipt-validation-based: entitlement state is correct on cold launch with no network round-trip, refunds propagate in seconds, and the entitlement layer runs at no cost.

## Docs

* Migrate from RevenueCat: https://superwall.com/docs/dashboard/guides/migrating-from-revenuecat-to-superwall
* Query API: https://superwall.com/docs/dashboard/guides/query-clickhouse
* Webhooks: https://superwall.com/docs/integrations/webhooks
* Pricing: https://superwall.com/pricing

# Using RevenueCat

Handle a deep link in your app and use the delegate methods to link web checkouts with RevenueCat in Flutter.

After purchasing from a web paywall, the user will be redirected to your app by a deep link to redeem their purchase on device. Please follow our [Post-Checkout Redirecting](/docs/flutter/guides/web-checkout/post-checkout-redirecting) guide to handle this user experience.

> **Note:** If you're using Superwall to handle purchases, then you don't need to do anything here.

> **Warning:** You only need to use a `PurchaseController` if you want end-to-end control of the purchasing pipeline. The recommended way to use RevenueCat with Superwall is by putting it in observer mode.

If you're using your own `PurchaseController`, you should follow our [Redeeming In-App](/docs/flutter/guides/web-checkout/linking-membership-to-iOS-app) guide.

### Using a PurchaseController with RevenueCat

If you're using RevenueCat, you'll need to follow [steps 1 to 4 in their guide](https://www.revenuecat.com/docs/web/integrations/stripe) to set up Stripe with RevenueCat. Then, you'll need to
associate the RevenueCat customer with the Stripe subscription IDs returned from redeeming the code. You can do this by extracting the ids from the `RedemptionResult` and sending them to RevenueCat's API
by using the `didRedeemLink()` delegate method:

> **Warning:** This flow is for Stripe subscriptions. Stripe one-time purchases can return Stripe Checkout session IDs through the same legacy `stripeSubscriptionIds` field, but those IDs are not Stripe subscription IDs. Handle one-time purchases with Superwall entitlements or your own backend instead of sending those IDs to RevenueCat's Stripe subscription endpoint.

```dart
import 'package:superwallkit_flutter/superwallkit_flutter.dart';
import 'package:purchases_flutter/purchases_flutter.dart';
import 'package:http/http.dart' as http;
import 'dart:convert';

class MySuperwallDelegate extends SuperwallDelegate {
  // The user tapped on a deep link to redeem a code
  @override
  void willRedeemLink() {
    print('[!] willRedeemLink');
    // Optionally show a loading indicator here
  }

  // Superwall received a redemption result and validated the purchase with Stripe.
  @override
  void didRedeemLink(RedemptionResult result) async {
    print('[!] didRedeemLink: $result');
    // Send Stripe IDs to RevenueCat to link purchases to the customer

    if (result is! RedemptionResultSuccess) {
      return;
    }

    final storeIdentifiers = result.redemptionInfo.purchaserInfo.storeIdentifiers;
    if (storeIdentifiers is! StripeStoreIdentifiers) {
      return;
    }

    // Get a list of Stripe subscription ids tied to the customer
    final stripeSubscriptionIds = storeIdentifiers.subscriptionIds;
    if (stripeSubscriptionIds.isEmpty) {
      return;
    }

    const revenueCatStripePublicAPIKey = 'strp.....'; // replace with your RevenueCat Stripe Public API Key
    final appUserId = await Purchases.appUserID;

    // In the background, send requests to RevenueCat
    for (final stripeSubscriptionId in stripeSubscriptionIds) {
        try {
          final url = Uri.parse('https://api.revenuecat.com/v1/receipts');
          final response = await http.post(
            url,
            headers: {
              'Content-Type': 'application/json',
              'Accept': 'application/json',
              'X-Platform': 'stripe',
              'Authorization': 'Bearer $revenueCatStripePublicAPIKey',
            },
            body: jsonEncode({
              'app_user_id': appUserId,
              'fetch_token': stripeSubscriptionId,
            }),
          );

          if (response.statusCode != 200) {
            throw Exception(
              'RevenueCat responded with ${response.statusCode}: ${response.body}',
            );
          }

          final json = jsonDecode(response.body);
          print('[!] Success: linked $stripeSubscriptionId to user $appUserId: $json');
        } catch (error) {
          print('[!] Error: unable to link $stripeSubscriptionId to user $appUserId: $error');
        }
    }

    // After all network calls complete, invalidate the cache
    try {
      final customerInfo = await Purchases.getCustomerInfo();
      
      /// If you're using Purchases.customerInfoStream, or keeping Superwall Entitlements in sync
      /// via RevenueCat's PurchasesDelegate methods, you don't need to do anything here. Those methods will be
      /// called automatically when this call fetches the most up to date customer info, ignoring any local caches.
      
      /// Otherwise, if you're manually calling Purchases.getCustomerInfo to keep Superwall's entitlements
      /// in sync, you should use the newly updated customer info here to do so.
      
      /// You could always access web entitlements here as well
      /// final webEntitlements = Superwall.shared.entitlements?.web;
      
      // Perform UI updates, like letting the user know their subscription was redeemed
      print('[!] Customer info updated after redemption');
    } catch (error) {
      print('[!] Error fetching customer info: $error');
    }
  }
}
```

> **Note:** The example throws when RevenueCat responds with an error so you can add retries, alerts, or custom
> UI. Adapt the error-handling strategy to your networking and logging requirements.

Set up the delegate when configuring Superwall:

```dart
void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  
  await Superwall.configure('pk_your_api_key');
  
  // Set the delegate
  Superwall.shared.setDelegate(MySuperwallDelegate());
  
  runApp(MyApp());
}
```

> **Warning:** If you call `logIn` from RevenueCat's SDK, then you need to call the logic you've implemented
> inside `didRedeemLink()` again. For example, that means if `logIn` was invoked from
> RevenueCat, you'd either abstract out this logic above into a function to call again, or simply
> call this function directly.

The web entitlements will be returned along with other existing entitlements in the `CustomerInfo` object accessible via RevenueCat's SDK.

If you're logging in and out of RevenueCat, make sure to resend the Stripe subscription IDs to RevenueCat's endpoint after logging in.

### Alternative implementation using async/await properly

Here's a cleaner implementation that properly handles async operations:

```dart
class MySuperwallDelegate extends SuperwallDelegate {
  @override
  void willRedeemLink() {
    print('[!] willRedeemLink');
    // Show loading indicator
  }

  @override
  void didRedeemLink(RedemptionResult result) {
    // Don't use async here directly, spawn a separate task
    _handleRedemption(result);
  }
  
  Future<void> _handleRedemption(RedemptionResult result) async {
    if (result is! RedemptionResultSuccess) {
      print('[!] Redemption did not succeed');
      return;
    }

    final storeIdentifiers = result.redemptionInfo.purchaserInfo.storeIdentifiers;
    if (storeIdentifiers is! StripeStoreIdentifiers) {
      print('[!] Redemption did not come from Stripe');
      return;
    }

    final stripeSubscriptionIds = storeIdentifiers.subscriptionIds;
    if (stripeSubscriptionIds.isEmpty) {
      print('[!] No Stripe subscription IDs found');
      return;
    }

    const revenueCatStripePublicAPIKey = 'strp.....';
    final appUserId = await Purchases.appUserID;

    // Link each subscription to RevenueCat
    await Future.wait(
      stripeSubscriptionIds.map((stripeSubscriptionId) async {
        try {
          await _linkSubscriptionToRevenueCat(
            stripeSubscriptionId,
            appUserId,
            revenueCatStripePublicAPIKey,
          );
        } catch (e) {
          print('[!] Failed to link $stripeSubscriptionId: $e');
        }
      }),
    );

    // Refresh customer info
    try {
      await Purchases.getCustomerInfo();
      print('[!] Successfully refreshed customer info');
    } catch (e) {
      print('[!] Failed to refresh customer info: $e');
    }
  }
  
  Future<void> _linkSubscriptionToRevenueCat(
    String stripeSubscriptionId,
    String appUserId,
    String apiKey,
  ) async {
    final url = Uri.parse('https://api.revenuecat.com/v1/receipts');
    final response = await http.post(
      url,
      headers: {
        'Content-Type': 'application/json',
        'Accept': 'application/json',
        'X-Platform': 'stripe',
        'Authorization': 'Bearer $apiKey',
      },
      body: jsonEncode({
        'app_user_id': appUserId,
        'fetch_token': stripeSubscriptionId,
      }),
    );

    if (response.statusCode != 200) {
      throw Exception(
        'RevenueCat responded with ${response.statusCode}: ${response.body}',
      );
    }

    print('[!] Successfully linked $stripeSubscriptionId to $appUserId');
  }
}
```

Remember to add the `http` package to your `pubspec.yaml`:

```yaml
dependencies:
  http: ^1.1.0
  purchases_flutter: ^6.0.0
  superwallkit_flutter: ^2.4.12
```