ax-storekit

StoreKit 2 In-App Purchases

iOS 15+ (iOS 18.4+ for latest features) | WWDC 2025-241, 2025-249, 2023-10013, 2021-10114

Quick Patterns

Testing-First Workflow

StoreKit Config -> Local Testing -> Production Code -> Unit Tests -> Sandbox Testing

1. Xcode -> File -> New -> StoreKit Configuration File (save as Products.storekit)
2. Add products: consumable / non-consumable / auto-renewable subscription
3. Scheme -> Edit Scheme -> Run -> Options -> StoreKit Configuration: select file
4. Run app in simulator, verify products load and purchases complete
5. THEN write production code

Benefits: product ID typos caught in Xcode (not runtime), no App Store Connect dependency, teammates test locally, accelerated subscription renewal.

StoreManager Architecture (Centralized, Required)

@MainActor
final class StoreManager: ObservableObject {
    @Published private(set) var products: [Product] = []
    @Published private(set) var purchasedProductIDs: Set<String> = []

    private let productIDs = ["com.app.coins_100", "com.app.premium", "com.app.pro_monthly"]
    private var transactionListener: Task<Void, Never>?

    init() {
        transactionListener = listenForTransactions()
        Task { await loadProducts(); await updatePurchasedProducts() }
    }

    deinit { transactionListener?.cancel() }

    func loadProducts() async {
        do { products = try await Product.products(for: productIDs) }
        catch { print("Failed to load products: \(error)") }
    }

    func listenForTransactions() -> Task<Void, Never> {
        Task.detached { [weak self] in
            for await result in Transaction.updates {
                await self?.handleTransaction(result)
            }
        }
    }

    private func handleTransaction(_ result: VerificationResult<Transaction>) async {
        guard let transaction = try? result.payloadValue else { return }
        if transaction.revocationDate != nil {
            await revokeEntitlement(for: transaction.productID)
        } else {
            await grantEntitlement(for: transaction)
        }
        await transaction.finish() // CRITICAL: always finish
        await updatePurchasedProducts()
    }

    func updatePurchasedProducts() async {
        var purchased: Set<String> = []
        for await result in Transaction.currentEntitlements {
            if let tx = try? result.payloadValue, tx.revocationDate == nil {
                purchased.insert(tx.productID)
            }
        }
        purchasedProductIDs = purchased
    }
}