StoreKit

StoreKit 2 patterns for implementing in-app purchases with async/await APIs, automatic verification, and SwiftUI integration.

Reference Loading Guide

ALWAYS load reference files if there is even a small chance the content may be required. It's better to have the context than to miss a pattern or make a mistake.

Reference Load When

Getting Started Setting up .storekit configuration file, testing-first workflow

Products Loading products, product types, purchasing with Product.purchase()

Subscriptions Auto-renewable subscriptions, subscription groups, offers, renewal tracking

Transactions Transaction listener, verification, finishing transactions, restore purchases

StoreKit Views ProductView, SubscriptionStoreView, SubscriptionOfferView in SwiftUI

Core Workflow

• Create .storekit configuration file first (before any code)

• Test purchases locally in Xcode simulator

• Implement centralized StoreManager with @MainActor

• Set up Transaction.updates listener at app launch

• Display products with ProductView or custom UI

• Always call transaction.finish() after granting entitlements

Essential Architecture

@MainActor final class StoreManager: ObservableObject { @Published private(set) var products: [Product] = [] @Published private(set) var purchasedProductIDs: Set<String> = [] private var transactionListener: Task<Void, Never>?

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

}

Common Mistakes

Missing .finish() calls on transactions — Forgetting to call transaction.finish() after granting entitlements causes transactions to never complete. The user won't see their purchase reflected. Always call finish() .

Unsafe StoreManager state — Shared StoreManager without @MainActor can have race conditions. Multiple async tasks can update @Published properties concurrently, corrupting state. Use @MainActor for thread safety.

No transaction listener at app launch — Not setting up Transaction.updates listener means app crashes or misses refunded/canceled purchases. Listen for transactions immediately in @main , not when user taps purchase button.

Hardcoded product IDs — Hardcoded IDs make testing and localization hard. Use configuration files or environment variables for product IDs. Same applies to prices (fetch from App Store, don't hardcode).

Ignoring verification failures — App Store verification fails silently sometimes. Not checking verification status means accepting unverified transactions (security risk). Always verify before granting entitlements.