The rewrite tax

Store APIs×Frameworks=Repeated work

01
APIs diverge
Methods, types, and events change with every store and SDK.
02
Fixes repeat
Maintainers solve the same lifecycle and error cases in parallel.
03
Platforms drift
StoreKit and Play Billing updates reach each framework differently.

02 / The contract

One source, many targets

Change the contract once. Generate the same shape for every language, then implement it against the native stores.

SourceGraphQL schemaOne contract
GenerateNative typesSwift · Kotlin · TS · Dart · C# · GDScript
ImplementStore modulesStoreKit 2 · Play Billing
ShipFramework SDKsOne API in every runtime

Native core

openiap-appleStoreKit 2 openiap-googlePlay Billing 9.1 View the schema

03 / The API

A small surface on purpose

Methods

Start and complete the purchase lifecycle

initConnection()fetchProducts()requestPurchase()finishTransaction()

Types

Share one model without hiding native fields

ProductPurchaseProductSubscriptionPurchaseError

Events

React to state changes with predictable signals

purchaseUpdatedListenerpurchaseErrorListenersubscriptionBillingIssueListener

04 / Generated types

Same model, native language

Each target gets idiomatic generated types while the field model stays aligned across the ecosystem.

swift

func displayLabel(for product: Product) -> String {
    switch product {
    case let .productIos(ios):
        return ios.title + " " + ios.displayNameIOS
    case let .productAndroid(android):
        return android.title + " " + android.nameAndroid
    }
}

05 / Runtime