llms.txt

# OpenIAP Quick Reference

> OpenIAP: Unified in-app purchase specification for iOS & Android
> Documentation: https://openiap.dev
> Full Reference: https://openiap.dev/llms-full.txt
> Generated: 2026-05-08T10:48:46.778Z

## Installation

### React Native / Expo
```bash
# expo-iap (Expo projects)
npx expo install expo-iap

# react-native-iap (React Native CLI)
npm install react-native-iap
```

### Native
```swift
// Swift Package Manager
.package(url: "https://github.com/hyodotdev/openiap.git", from: "1.0.0")
```

```kotlin
// Gradle
implementation("io.github.hyochan.openiap:openiap-google:1.0.0")
```

```yaml
# Flutter
dependencies:
  flutter_inapp_purchase: ^5.0.0
```

```gdscript
# Godot
# Install godot-iap to addons/godot-iap and enable the plugin
```

```kotlin
// Kotlin Multiplatform
implementation("io.github.hyochan.kmpiap:library:1.3.8")
```

```xml
<!-- .NET MAUI -->
<PackageReference Include="OpenIap.Maui" Version="1.0.1" />
```

## Framework Libraries

- `expo-iap`: Expo Modules wrapper, same OpenIAP API as React Native.
- `react-native-iap`: Nitro Modules wrapper for React Native CLI apps.
- `flutter_inapp_purchase`: Dart API with generated OpenIAP types and streams.
- `godot-iap`: Godot 4.x plugin with GDScript functions and signals.
- `kmp-iap`: Kotlin Multiplatform API with Flow-based purchase events.
- `maui-iap`: `OpenIap.Maui` package with `Iap.Instance`,
  generated `Types.cs`, IAPKit helpers (`Iap.KitApi`,
  `Iap.ConnectWebhookStream`, `Iap.ParseWebhookEventData`), flattened iOS
  xcframework / Android AAR bindings in one NuGet package, and MAUI example
  flows matching `expo-iap`.

## Core APIs

### Connection
```typescript
// Initialize (required before any operation)
await initConnection();

// With alternative billing (Android)
await initConnection({ alternativeBillingModeAndroid: 'user-choice' });

// Cleanup on unmount
await endConnection();
```

### Fetch Products
```typescript
const products = await fetchProducts({
  products: [
    { id: 'com.app.premium', type: 'inapp' },
    { id: 'com.app.monthly', type: 'subs' },
  ],
});
```

### Request Purchase
```typescript
// IMPORTANT: requestPurchase is event-based, not promise-based
// Set up purchaseUpdatedListener before calling
await requestPurchase({
  request: {
    apple: { sku: 'com.app.premium' },
    google: { skus: ['com.app.premium'] },
  },
  type: 'inapp', // 'inapp' | 'subs'
});
```

### Finish Transaction
```typescript
// CRITICAL: Must call after verification
// Android: purchases auto-refund after 3 days if not acknowledged
await finishTransaction(purchase, isConsumable);
```

### Get Available Purchases
```typescript
const purchases = await getAvailablePurchases();
// Returns user's current entitlements
```

### Restore Purchases
```typescript
await restorePurchases();
const purchases = await getAvailablePurchases();
```

## Events (React Native/Expo)

```typescript
import { purchaseUpdatedListener, purchaseErrorListener } from 'expo-iap';

// Set up before any purchase request
const purchaseUpdateSubscription = purchaseUpdatedListener(async (purchase) => {
  // 1. Verify purchase on server
  // 2. Grant entitlement
  // 3. Finish transaction
  await finishTransaction(purchase);
});

const purchaseErrorSubscription = purchaseErrorListener((error) => {
  if (error.code === 'UserCancelled') return; // Normal flow
  console.error('Purchase error:', error.message);
});

// Cleanup
purchaseUpdateSubscription.remove();
purchaseErrorSubscription.remove();
```

## Core Types

### Product
```typescript
interface Product {
  id: string;           // Product identifier (SKU)
  title: string;        // Display name
  description: string;  // Product description
  price: string;        // Formatted price string
  priceAmount: number;  // Price as number
  currency: string;     // ISO 4217 currency code
  type: 'inapp' | 'subs';
}
```

### Purchase
```typescript
interface Purchase {
  productId: string;         // Purchased product ID
  transactionId: string;     // Platform transaction ID
  transactionDate: number;   // Purchase timestamp
  purchaseState: PurchaseState;
  // iOS specific
  originalTransactionId?: string;
  // Android specific
  purchaseToken?: string;
  orderId?: string;
}

type PurchaseState = 'purchased' | 'pending' | 'restored';
```

### PurchaseError
```typescript
interface PurchaseError {
  code: string;       // Error code
  message: string;    // Human-readable message
  productId?: string; // Related SKU
}
```

## Common Error Codes

| Code | Description | Action |
|------|-------------|--------|
| UserCancelled | User cancelled purchase | No action needed |
| ItemUnavailable | Product not in store | Check store config |
| AlreadyOwned | Already purchased | Restore purchases |
| NetworkError | Network issue | Retry with backoff |
| ServiceError | Store service error | Retry later |
| NotPrepared | initConnection not called | Call initConnection first |

## API Naming Convention

- **Cross-platform**: No suffix (fetchProducts, requestPurchase)
- **iOS-only**: `IOS` suffix (syncIOS, getStorefrontIOS)
- **Android-only**: `Android` suffix (acknowledgePurchaseAndroid)

## Platform-Specific APIs

### iOS
- syncIOS() - Sync with App Store
- presentCodeRedemptionSheetIOS() - Show offer code UI
- showManageSubscriptionsIOS() - Open subscription management
- beginRefundRequestIOS() - Start refund flow

### Android
- acknowledgePurchaseAndroid() - Acknowledge purchase
- consumePurchaseAndroid() - Consume for re-purchase

## Purchase Flow Summary

1. initConnection()
2. fetchProducts([...skus])
3. Set up purchaseUpdatedListener
4. requestPurchase({ sku })
5. In listener: verify -> grant -> finishTransaction()
6. endConnection() on cleanup

## Links

- Docs: https://openiap.dev/docs
- Types: https://openiap.dev/docs/types
- APIs: https://openiap.dev/docs/apis
- Errors: https://openiap.dev/docs/errors
- GitHub: https://github.com/hyodotdev/openiap