💰 Flutter In-App Subscriptions

Production-ready subscription flows with App Store & Play Store integration

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🚀 Key Features

Feature	Description
📱 Cross-Platform	Unified API for iOS/Android subscription management
🎯 Introductory Offers	First-time user discounts & free trials
🔒 Purchase Validation	Server-side receipt verification
📊 Analytics	Track conversion rates & churn metrics
🔄 Restore Purchases	Seamless entitlement recovery

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🛠 Tech Stack

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⚡ Quick Start

Prerequisites

• Flutter 3.22+
• App Store Developer Account ($99/year)
• Google Play Developer Account ($25 one-time)

Installation

1. Add Dependency

   dependencies:
     in_app_purchase: ^3.1.7

2. Platform Setup

📱 iOS Configuration

1. Enable In-App Purchases in Xcode capabilities
2. Create subscriptions in App Store Connect
3. Add StoreKit configuration file:

// ios/Runner/Config.storekit
{
  "products": [
    {
      "identifier": "premium_monthly",
      "type": "subscription"
    }
  ]
}

🤖 Android Configuration

1. Add billing permission:

<!-- android/app/src/main/AndroidManifest.xml -->
<uses-permission android:name="com.android.vending.BILLING" />

2. Configure products in Play Console:

Monetize → Products → Subscriptions

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🛒 Purchase Flow Architecture

sequenceDiagram
  participant User
  participant App
  participant Store
  participant Server
  
  User->>App: Initiate Purchase
  App->>Store: Request Products
  Store-->>App: Return Product List
  App->>User: Show Options
  User->>Store: Confirm Payment
  Store-->>App: Purchase Token
  App->>Server: Validate Receipt
  Server-->>App: Grant Access

Loading

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💻 Code Snippets

Fetch Subscription Plans

Future<List<ProductDetails>> fetchSubscriptions() async {
  const Set<String> _kSubscriptionIds = {'premium_monthly', 'premium_yearly'};
  final response = await InAppPurchase.instance.queryProductDetails(_kSubscriptionIds);
  return response.productDetails;
}

Handle Purchase Updates

InAppPurchase.instance.purchaseStream.listen((purchases) {
  purchases.forEach((purchase) {
    if (purchase.status == PurchaseStatus.purchased) {
      _verifyPurchase(purchase); // Server-side validation
      InAppPurchase.instance.completePurchase(purchase);
    }
  });
});

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🎁 Introductory Offers Implementation

iOS (App Store)

// StoreKit configuration for free trial
{
  "identifier": "premium_monthly",
  "introductoryPrice": "7.99",
  "introductoryPriceNumberOfPeriods": 1,
  "introductoryPriceSubscriptionPeriod": "month"
}

Android (Play Store)

<!-- Play Console introductory pricing -->
<subscription 
  introductoryPrice="4.99"
  introductoryPricePeriod="P1M"
  introductoryPriceCycles="3"/>

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📊 Subscription Metrics Dashboard

Metric	Target Value
Conversion Rate	>12%
Trial-to-Paid	>35%
Monthly Churn	<5%
ARPU	>$8.50

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🚨 Troubleshooting

Error	Solution
Product Not Found	Verify store configuration
Purchase Pending	Check network connectivity
Validation Failed	Update server receipt parser

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🤝 Contributing

1. Fork repository
2. Create feature branch: git checkout -b feat/subscription-analytics
3. Commit changes: git commit -m 'Add revenue tracking'
4. Push to branch: git push origin feat/subscription-analytics
5. Open pull request