Push notifications engage users with timely, relevant information. Register for remote notifications with UNUserNotificationCenter. Request authorization with requestAuthorization(options:). Implement application:didRegisterForRemoteNotificationsWithDeviceToken. APNs device token identifies the app installation. Payload format follows APNs specification with aps dictionary. Alert, badge, sound configure notification appearance. Category identifiers group notification actions. UNNotificationAction defines buttons displayed on notification. UNNotificationCategory groups related actions. Rich notifications include images, video, and audio attachments. Notification service extension modifies content before display. Notification content extension shows custom UI on long press. Silent notifications wake app in background for data refresh. Background modes configure capabilities for remote notifications. Handle foreground notifications by displaying custom UI. Notification grouping organizes multiple notifications. Critical alerts bypass silent mode for emergencies. VoIP pushes use PushKit for immediate delivery. Test notifications with NWPusher or Firebase Console. Push notifications require careful design to avoid user .
