RevenueCat

If RevenueCat already manages your in-app purchases, its webhook is the shortest route: one endpoint, one header, and both stores' purchases, renewals and refunds arrive as a single kind of event. You then need neither the Google Play nor the App Store setup.

1. 1Revenue tab → Connect RevenueCat. Choose any value for the Authorization header and Save. It is a shared secret: we compare it constant-time on every event.
2. 2RevenueCat → Project settings → Integrations → Webhooks → Add. URL: the one on the Revenue tab. Authorization header: the same value.
3. 3Press RevenueCat's Send test event. Within seconds the Revenue tab moves from *Waiting for the first event* to confirming the URL, without waiting for a real purchase.

https://api.roassensor.com/api/tracking/webhooks/revenuecat/YOUR_PUBLIC_KEY

RevenueCat identifies a customer by app_user_id. Configure it with our visitor id, and every event carries the thread back to the install:

// Kotlin
Purchases.configure(PurchasesConfiguration.Builder(context, apiKey).appUserID(Roas.visitorId()).build())

// Swift
Purchases.configure(withAPIKey: apiKey, appUserID: Roas.visitorId())

Both SDKs are initialised at launch, so this is an ordering, not a race: ours first, then RevenueCat with the id ours returns.

Events with environment: SANDBOX -- a StoreKit tester or a Play licence tester -- are flagged is_test and kept out of reported figures. An event missing the field is treated as real money, deliberately: dropping genuine revenue on the strength of a field that was not sent is the more expensive mistake.