Push notifications

Middle PRO

How it works

1. The app asks the user for permission (UNUserNotificationCenter.requestAuthorization) and registers with APNs (registerForRemoteNotifications()).
2. APNs (Apple Push Notification service) issues a device token — it arrives in application(_:didRegisterForRemoteNotificationsWithDeviceToken:). The token is unique per app+device pair and may change (reinstall, restore from backup) — send it to your server on every launch.
3. Your server (or a provider: Firebase, OneSignal, Braze) sends the payload to APNs over HTTP/2 at api.push.apple.com, specifying the device token.
4. APNs delivers the notification to the device; the system shows a banner or wakes the app.