paymentPendingError (error code 20): Payment pending

• StoreKit 2: the purchase result is .pending, which Apple describes as a purchase that requires action from the customer. The SDK throws paymentPendingError (StoreKit2TransactionListener.swift).
• StoreKit 1: a transaction in the deferred state, which Apple describes as pending external action such as Ask to Buy.
• Android: the Play purchase state is PENDING. The SDK raises this error instead of posting the purchase (PostReceiptHelper.kt). Google says to grant entitlement only when the state is PURCHASED (Google docs).
• The backend answered 7651 (payment not complete), which the Android SDK maps here.

• Do not retry the purchase. The customer would start a second one.
• Do not grant access until CustomerInfo shows the entitlement active.
• Treat it as a state, not an error: store a "pending" flag for the product so the paywall can say so on the next launch.

// Swift
do {
  let result = try await Purchases.shared.purchase(package: package)
} catch let error as ErrorCode where error == .paymentPendingError {
  // handle payment pending
}

// Kotlin
if (error.code == PurchasesErrorCode.PaymentPendingError) { /* ... */ }

On RevenueDot: The Android SDK does not post pending purchases, so RevenueDot normally never sees them. If a pending Google purchase does reach POST /v1/receipts, RevenueDot answers 503 with code 7101, so the SDK posts it again later, and a cancelled pending purchase gets 400 with 7103.