What is the App Store Server API?

Calls use a JSON Web Token as a bearer token, signed with a key you create in App Store Connect. Apple provides the open-source App Store Server Library in four languages, which creates the tokens and verifies the signed data. The API works whether or not the customer has your app installed, because it answers from the customer's purchase history. Every endpoint except one is available in the sandbox at a separate base URL, and a transaction identifier must be sent to the environment that created it.

Typical uses: get all subscription statuses to learn whether a subscriber is active, in a grace period or in billing retry; get the transaction history; send consumption information after a refund request; extend a subscription's renewal date to make up for an outage; look up an order from the ID on a customer's receipt email; and request a test notification.

RevenueDot uses the API with the app's In-App Purchase key to confirm each StoreKit 2 purchase, read the full history and renewal state, and extend subscriptions. It can also look up an order ID for a support restore. Without the key RevenueDot still verifies signed transactions against Apple's root certificate, but it knows only what the device sent.

Sources: Apple: App Store Server API · Apple: Look Up Order ID · Apple: Send Consumption Information