# subscriptionIntroductoryOffer(applyOffer:compactJWS:) Selects the introductory offer eligibility preference to apply to a purchase a customer makes from a subscription store view. ``` nonisolated func subscriptionIntroductoryOffer(applyOffer: @escaping (Product, Product.SubscriptionInfo) -> Bool, compactJWS: @escaping (Product, Product.SubscriptionInfo) async throws -> String) -> some View ``` ## Parameters `applyOffer` The system calls this function before drawing the given subscription product on the subscription store view. Return if the introductory offer should be applied to a given product, if any, to have system-provided UI reflect the discounted terms under the selected offer. `compactJWS` The system calls this function before processing a purchase, with the product to be purchased provided as a parameter. Return a compact JWS signature you generate on your server that validates the selected offer eligibility preference. Errors thrown from this closure will be surfaced via the [`onInAppPurchaseCompletion(perform:)`](/documentation/SwiftUI/View/onInAppPurchaseCompletion(perform:)) modifier. For information about generating the JWS signature, see . ## Discussion Subscription stores within this view uses the introductory subscription offers to configure the appearance of the subscription plans displayed, when you use a system-provided to style the in-app subscription store. Standard instances don’t show introductory or promotional offers in UI, instead use . Determine if the introductory offer should be displayed in the view and applied to the purchase using the `applyOffer`. If the signature passes validation, the system applies or removes the offer to the purchases according to the offer eligibility preference. If the signature fails validation, the purchase will fail with . --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)