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Skill
Review
Audit score 70

storekit

dpearson2699/swift-ios-skills

Implement in-app purchases and subscriptions using StoreKit 2 on iOS 16+.

What is storekit?

StoreKit 2 skill provides modern Swift APIs for building paywalls, processing transactions, verifying entitlements, and managing subscriptions. Use this when implementing in-app purchases, subscriptions, offer codes, Family Sharing, Ask to Buy, refund handling, and StoreKit testing.

  • Build paywalls with SubscriptionStoreView, ProductView, and StoreView (iOS 17+)
  • Process purchases and transactions with Product and Transaction APIs
  • Verify entitlements and manage subscription status and renewal state
  • Handle purchase flows: consumable, non-consumable, auto-renewable, and non-renewing
  • Implement offer codes, promotional offers, introductory offers, and win-back offers
  • Set up StoreKit testing with configuration files and manage Family Sharing, Ask to Buy, refunds, and billing retry logic

How to install storekit

npx skills add https://github.com/dpearson2699/swift-ios-skills --skill storekit
Prerequisites
  • iOS 16 or later (iOS 17+ for SubscriptionStoreView and ProductView)
  • Xcode with StoreKit 2 support
  • App Store Connect configured with in-app purchase products
Claude Code
Cursor
Windsurf
Cline

How to use storekit

  1. 1.Define product IDs as constants matching App Store Connect configuration
  2. 2.Load products using Product.products(for:) with your product ID list
  3. 3.Start Transaction.updates listener at app launch to catch purchases from other devices, renewals, and refunds
  4. 4.Use SubscriptionStoreView or ProductView for standard paywalls, or PurchaseAction for custom SwiftUI buttons
  5. 5.Verify every VerificationResult before granting access, deliver content, then call transaction.finish()
  6. 6.Check Transaction.currentEntitlements for active entitlements and exclude refunded/revoked transactions

Use cases

Good for
  • Building a premium subscription paywall with auto-renewable plans and introductory offers
  • Implementing consumable in-app purchases (gems, coins) with restore functionality
  • Verifying user entitlements at app launch and handling refunds or revocations
  • Testing purchase flows locally with StoreKit configuration files before App Store submission
  • Managing subscription renewal state and grace-period handling across devices
Who it's for
  • iOS app developers implementing monetization
  • SwiftUI developers building paywalls and purchase flows
  • Backend engineers integrating App Store Server API for verification
  • QA engineers testing in-app purchase and subscription scenarios

storekit FAQ

What is the difference between PurchaseAction and product.purchase(options:)?

PurchaseAction is the preferred SwiftUI path for custom purchase buttons in the environment. Direct product.purchase(options:) is valid for lower-level custom StoreKit flows that need direct control. Standard paywalls should use SubscriptionStoreView, ProductView, or StoreView.

When should I use Transaction.updates vs Transaction.currentEntitlements?

Transaction.updates is a listener started at app launch that catches purchases from other devices, Family Sharing changes, renewals, Ask to Buy approvals, refunds, and revocations. Transaction.currentEntitlements is a snapshot of active entitlements (non-consumables, active auto-renewable subscriptions, non-renewing subscriptions) at any point in time.

What does Transaction.currentEntitlements cover?

It covers non-consumables, active or grace-period auto-renewable subscriptions, and non-renewing subscriptions. It does not include consumable purchases or delivery history, which must be tracked in your app or server ledger.

How do I handle pending Ask to Buy approvals?

When a purchase returns .pending, show a pending approval message to the user. Do not unlock content until a verified transaction arrives through the Transaction.updates listener after approval.

What should I verify before granting access to content?

Always verify every VerificationResult before granting access. Deliver or persist the entitlement first, then call transaction.finish(). Exclude refunded or revoked transactions from active entitlement state.

Full instructions (SKILL.md)

Source of truth, from dpearson2699/swift-ios-skills.


name: storekit description: "Implement, review, or improve in-app purchases and subscriptions using StoreKit 2. Use when building paywalls with SubscriptionStoreView or ProductView, processing transactions with Product and Transaction APIs, verifying entitlements, handling purchase flows (consumable, non-consumable, auto-renewable), implementing offer codes or promotional/win-back/introductory offers, managing subscription status and renewal state, setting up StoreKit testing with configuration files, or integrating Family Sharing, Ask to Buy, refund handling, and billing retry logic."

StoreKit 2 In-App Purchases and Subscriptions

Implement in-app purchases, subscriptions, paywalls, and StoreKit testing using StoreKit 2 on iOS 26+. Use the modern Swift-based Product, Transaction, PurchaseAction, StoreView, and SubscriptionStoreView APIs. Avoid original In-App Purchase APIs (SKProduct, SKPaymentQueue) unless legacy OS support requires them.

When reviewing StoreKit code, explicitly separate "preferred SwiftUI path" from "invalid API": PurchaseAction is the preferred custom SwiftUI button path, but direct product.purchase(options:) is still valid for lower-level custom StoreKit flows.

Contents

Implementation Review Minimums

When reviewing a paywall, purchase manager, or entitlement gate, include these points explicitly:

  • Standard SwiftUI paywalls should prefer StoreView, ProductView, or SubscriptionStoreView; custom SwiftUI buy buttons should prefer PurchaseAction; direct product.purchase(options:) is valid for lower-level custom StoreKit flows.
  • Transaction.updates must start at app launch because it catches purchases from other devices, Family Sharing changes, renewals, Ask to Buy approvals, refunds, revocations, and unfinished transactions.
  • Include this entitlement-scope sentence verbatim when reviewing Transaction.currentEntitlements: "It covers non-consumables, active or grace-period auto-renewable subscriptions, and non-renewing subscriptions; it does not include consumable purchase or delivery history."
  • Verify every VerificationResult before granting access. Deliver or persist the entitlement first, then call transaction.finish().
  • Pending purchases and user cancellations never unlock content; pending Ask to Buy approvals unlock only after a verified transaction arrives through the launch-time listener.
  • Exclude refunded or revoked transactions from active entitlement state and re-check entitlements when refunds or revocations arrive through Transaction.updates.
  • Provide a visible restore purchases path and Terms of Service / Privacy Policy links on subscription paywalls.

Product Types

TypeEnum CaseBehavior
Consumable.consumableUsed once, can be repurchased (gems, coins)
Non-consumable.nonConsumablePurchased once permanently (premium unlock)
Auto-renewable.autoRenewableRecurring billing with automatic renewal
Non-renewing.nonRenewingTime-limited access without automatic renewal

Loading Products

Define product IDs as constants. Fetch products with Product.products(for:).

import StoreKit

enum ProductID {
    static let premium = "com.myapp.premium"
    static let gems100 = "com.myapp.gems100"
    static let monthlyPlan = "com.myapp.monthly"
    static let yearlyPlan = "com.myapp.yearly"
    static let all: [String] = [premium, gems100, monthlyPlan, yearlyPlan]
}

let products = try await Product.products(for: ProductID.all)
for product in products {
    print("\(product.displayName): \(product.displayPrice)")
}

Purchase Flow

Prefer StoreKit views for standard paywalls because they initiate purchases, restore purchases, and display policy controls. For custom SwiftUI purchase buttons, prefer PurchaseAction from the environment. Use direct product.purchase(options:) only for lower-level custom flows, and use purchase(confirmIn:options:) for UIKit or AppKit confirmation. Always handle every PurchaseResult, verify before access, deliver durably, then finish.

Review wording: do not call product.purchase(options:) inherently wrong. Say "prefer PurchaseAction for SwiftUI buttons; keep product.purchase(options:) for lower-level custom flows that need direct StoreKit control."

@Environment(\.purchase) private var purchase

func purchaseProduct(_ product: Product) async throws {
    let result = try await purchase(product, options: [
        .appAccountToken(userAccountToken)
    ])
    switch result {
    case .success(let verification):
        let transaction = try checkVerified(verification)
        await deliverContent(for: transaction)
        await transaction.finish()
    case .userCancelled:
        break
    case .pending:
        // Ask to Buy or deferred approval: show pending UI, no unlock yet.
        showPendingApprovalMessage()
    @unknown default:
        break
    }
}

func checkVerified<T>(_ result: VerificationResult<T>) throws -> T {
    switch result {
    case .verified(let value): return value
    case .unverified(_, let error): throw error
    }
}

Transaction.updates Listener

Start at app launch, not when a paywall appears. Catches purchases from other devices, Family Sharing changes, renewals, Ask to Buy approvals, refunds, revocations, and unfinished transactions Apple emits once immediately after launch. Keep the task retained for the app lifetime.

In implementation reviews, name the launch-time coverage explicitly: purchases made on other devices, Family Sharing changes, subscription renewals, Ask to Buy approvals, refunds, revocations, and unfinished transactions.

@main
struct MyApp: App {
    private let transactionListener: Task<Void, Never>

    init() {
        transactionListener = Self.listenForTransactions()
    }

    var body: some Scene {
        WindowGroup { ContentView() }
    }

    static func listenForTransactions() -> Task<Void, Never> {
        Task(priority: .background) {
            for await result in Transaction.updates {
                guard case .verified(let transaction) = result else { continue }
                await StoreManager.shared.updateEntitlements()
                await transaction.finish()
            }
        }
    }
}

Entitlement Checking

Use Transaction.currentEntitlements for non-consumables, active or grace period auto-renewable subscriptions, and non-renewing subscriptions. It excludes consumables and consumable delivery history; track consumable fulfillment in your own app or server ledger. It also excludes refunded or revoked transactions. Use Transaction.unfinished for unfinished consumables and recovery sweeps. Always check revocationDate when processing transactions.

In reviews, include this sentence verbatim: "Transaction.currentEntitlements covers non-consumables, active or grace-period auto-renewable subscriptions, and non-renewing subscriptions; it does not include consumable purchase or delivery history." Do not replace this with only a code sample or a revocation check.

@Observable
@MainActor
class StoreManager {
    static let shared = StoreManager()
    var purchasedProductIDs: Set<String> = []
    var isPremium: Bool { purchasedProductIDs.contains(ProductID.premium) }

    func updateEntitlements() async {
        var purchased = Set<String>()
        for await result in Transaction.currentEntitlements {
            if case .verified(let transaction) = result,
               transaction.revocationDate == nil {
                purchased.insert(transaction.productID)
            }
        }
        purchasedProductIDs = purchased
    }
}

SwiftUI .currentEntitlementTask Modifier

struct PremiumGatedView: View {
    @State private var state: EntitlementTaskState<VerificationResult<Transaction>?> = .loading

    var body: some View {
        Group {
            switch state {
            case .loading: ProgressView()
            case .failure: PaywallView()
            case .success(.some(.verified(let transaction))) where transaction.revocationDate == nil:
                PremiumContentView()
            case .success:
                PaywallView()
            }
        }
        .currentEntitlementTask(for: ProductID.premium) { state in
            self.state = state
        }
    }
}

SubscriptionStoreView (iOS 17+)

Built-in SwiftUI view for subscription paywalls. Handles product loading, purchase UI, and restore purchases automatically.

SubscriptionStoreView(groupID: "YOUR_GROUP_ID")
    .subscriptionStoreControlStyle(.prominentPicker)
    .subscriptionStoreButtonLabel(.multiline)
    .storeButton(.visible, for: .restorePurchases)
    .storeButton(.visible, for: .redeemCode)
    .subscriptionStorePolicyDestination(url: termsURL, for: .termsOfService)
    .subscriptionStorePolicyDestination(url: privacyURL, for: .privacyPolicy)
    .onInAppPurchaseCompletion { product, result in
        if case .success(.success(.verified(let transaction))) = result {
            await deliverContent(for: transaction)
            await transaction.finish()
        }
    }

Custom Marketing Content

SubscriptionStoreView(groupID: "YOUR_GROUP_ID") {
    VStack {
        Image(systemName: "crown.fill").font(.system(size: 60)).foregroundStyle(.yellow)
        Text("Unlock Premium").font(.largeTitle.bold())
        Text("Access all features").foregroundStyle(.secondary)
    }
}
.containerBackground(.blue.gradient, for: .subscriptionStore)

Hierarchical Layout

SubscriptionOptionGroup, SubscriptionOptionSection, and SubscriptionPeriodGroupSet are iOS 18+ helper views for organizing options inside SubscriptionStoreView.

SubscriptionStoreView(groupID: "YOUR_GROUP_ID") {
    SubscriptionPeriodGroupSet()
}
.subscriptionStoreControlStyle(.picker)

StoreView (iOS 17+)

Merchandises multiple products with localized names, prices, and purchase buttons.

StoreView(ids: [ProductID.gems100, ProductID.premium], prefersPromotionalIcon: true)
    .productViewStyle(.large)
    .storeButton(.visible, for: .restorePurchases)
    .onInAppPurchaseCompletion { product, result in
        if case .success(.success(.verified(let transaction))) = result {
            await deliverContent(for: transaction)
            await transaction.finish()
        }
    }

ProductView for Individual Products

ProductView(id: ProductID.premium) { iconPhase in
    switch iconPhase {
    case .success(let image): image.resizable().scaledToFit()
    case .loading: ProgressView()
    default: Image(systemName: "star.fill")
    }
}
.productViewStyle(.large)

Subscription Status Checking

func checkSubscriptionActive(groupID: String) async throws -> Bool {
    let statuses = try await Product.SubscriptionInfo.status(for: groupID)
    for status in statuses {
        guard case .verified = status.renewalInfo,
              case .verified = status.transaction else { continue }
        if status.state == .subscribed || status.state == .inGracePeriod {
            return true
        }
    }
    return false
}

Renewal States

StateMeaning
.subscribedActive subscription
.expiredSubscription has expired
.inBillingRetryPeriodPayment failed, Apple is retrying
.inGracePeriodPayment failed but access continues during grace period
.revokedApple refunded or revoked the subscription

Restore Purchases

StoreKit 2 handles restoration via Transaction.currentEntitlements. Add a restore button or call AppStore.sync() explicitly.

func restorePurchases() async throws {
    try await AppStore.sync()
    await StoreManager.shared.updateEntitlements()
}

On store views: .storeButton(.visible, for: .restorePurchases)

App Transaction (App Purchase Verification)

Verify the legitimacy of the app installation. Use for business model changes or detecting tampered installations (iOS 16+).

func verifyAppPurchase() async {
    do {
        let result = try await AppTransaction.shared
        switch result {
        case .verified(let appTransaction):
            let originalVersion = appTransaction.originalAppVersion
            let purchaseDate = appTransaction.originalPurchaseDate
            // Migration logic for users who paid before subscription model
        case .unverified:
            // Potentially tampered -- restrict features as appropriate
            break
        }
    } catch { /* Could not retrieve app transaction */ }
}

Purchase Options

// App account token for server-side reconciliation
try await product.purchase(options: [.appAccountToken(UUID())])

// Consumable quantity
try await product.purchase(options: [.quantity(5)])

// Simulate Ask to Buy in sandbox
try await product.purchase(options: [.simulatesAskToBuyInSandbox(true)])

SwiftUI Purchase Callbacks

.onInAppPurchaseStart { product in
    await analytics.trackPurchaseStarted(product.id)
}
.onInAppPurchaseCompletion { product, result in
    if case .success(.success(.verified(let transaction))) = result {
        await deliverContent(for: transaction)
        await transaction.finish()
    }
}
.inAppPurchaseOptions { product in
    [.appAccountToken(userAccountToken)]
}

Common Mistakes

1. Not starting Transaction.updates at app launch

// WRONG: No listener -- misses renewals, refunds, Ask to Buy approvals
@main struct MyApp: App {
    var body: some Scene { WindowGroup { ContentView() } }
}
// CORRECT: Start listener in App init (see Transaction.updates section above)

2. Forgetting transaction.finish()

// WRONG: Never finished -- reappears in unfinished queue forever
let transaction = try checkVerified(verification)
unlockFeature(transaction.productID)

// CORRECT: Deliver durably, then finish. If delivery fails, do not finish yet.
let transaction = try checkVerified(verification)
try await recordDelivery(transaction)
await transaction.finish()

3. Ignoring verification result

// WRONG: Using unverified transaction -- security risk
let transaction = verification.unsafePayloadValue

// CORRECT: Verify before using
let transaction = try checkVerified(verification)

4. Using original In-App Purchase APIs in new StoreKit 2 code

// AVOID: Original In-App Purchase APIs
let request = SKProductsRequest(productIdentifiers: ["com.app.premium"])
SKPaymentQueue.default().add(payment)

// PREFERRED: StoreKit 2
let products = try await Product.products(for: ["com.app.premium"])
let result = try await product.purchase()

5. Not checking revocationDate

// WRONG: Grants access to refunded purchases
if case .verified(let transaction) = result {
    purchased.insert(transaction.productID)
}

// CORRECT: Skip revoked transactions
if case .verified(let transaction) = result, transaction.revocationDate == nil {
    purchased.insert(transaction.productID)
}

6. Hardcoding prices

// WRONG: Wrong for other currencies and regions
Text("Buy Premium for $4.99")

// CORRECT: Localized price from Product
Text("Buy \(product.displayName) for \(product.displayPrice)")

7. Not handling .pending purchase result

// WRONG: Silently drops pending Ask to Buy
default: break

// CORRECT: Explain approval is pending; unlock only after Transaction.updates
case .pending:
    showPendingApprovalMessage()

8. Checking entitlements only once at launch

// WRONG: Check once, never update
func appDidFinish() { Task { await updateEntitlements() } }

// CORRECT: Re-check on Transaction.updates AND on foreground return
// Transaction.updates listener handles mid-session changes.
// Also use .task { await storeManager.updateEntitlements() } on content views.

9. Missing restore purchases button

// WRONG: No restore option -- App Store rejection risk
SubscriptionStoreView(groupID: "group_id")

// CORRECT
SubscriptionStoreView(groupID: "group_id")
    .storeButton(.visible, for: .restorePurchases)

10. Subscription views without policy links

// WRONG: No terms or privacy policy
SubscriptionStoreView(groupID: "group_id")

// CORRECT
SubscriptionStoreView(groupID: "group_id")
    .subscriptionStorePolicyDestination(url: termsURL, for: .termsOfService)
    .subscriptionStorePolicyDestination(url: privacyURL, for: .privacyPolicy)

Review Checklist

  • Transaction.updates listener starts at app launch in App init
  • All transactions verified before granting access
  • transaction.finish() called only after durable content delivery
  • Revoked/refunded transactions excluded and entitlement state updated
  • .pending result shows Ask to Buy/deferred-approval feedback
  • Restore purchases button visible on paywall and store views
  • Terms of Service and Privacy Policy links on subscription views
  • Prices shown using product.displayPrice, never hardcoded
  • Subscription terms (price, duration, renewal) clearly displayed
  • Free trial states post-trial pricing clearly
  • No original In-App Purchase APIs (SKProduct, SKPaymentQueue) unless legacy OS support requires them
  • Product IDs defined as constants, not scattered strings
  • StoreKit tests cover promotional offers, win-back, offer codes, Ask to Buy, renewals, refunds, and revocations
  • Entitlements re-checked on Transaction.updates and app foreground
  • Server-side validation uses jwsRepresentation if applicable
  • Consumables delivered and finished promptly
  • Transaction observer types and product model types are Sendable when shared across concurrency boundaries

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