push-notifications

What it does

Implements, reviews, and debugs local and remote notifications on iOS/macOS using UserNotifications and APNs. Covers permission flow, token registration, payload structure, foreground handling, notification actions, grouping, and rich notifications. Targets iOS 26+ with Swift 6.3, backward-compatible to iOS 16 unless noted.

How it works

• Emphasizes keeping adjacent domains separate for specific payload types (Live Activity, PushKit/VoIP, App Clips, background processing).
• Divides functionality into sections: Correction Reviews, Permission Flow, APNs Registration, Local Notifications, Remote Notification Payload, Notification Handling, Notification Actions and Categories, Notification Grouping, Common Mistakes, Review Checklist, References.
• Provides sample code blocks for requesting permission, checking status, registering for remote notifications, handling device tokens, and configuring notifications.
• Shows explicit Swift examples for creating content, various triggers (time, calendar, location), scheduling, and managing notifications.
• Details handling of remote notifications with both standard and silent/background payloads, including background fetch results and content-handling constraints for service extensions.
• Includes guidance on mutable-content service extensions, attachments, localization, and deep linking via a shared router pattern.
• Demonstrates UNUserNotificationCenterDelegate methods to control foreground display and user interaction, including handling default/dismiss/custom actions.
• Demonstrates defining notification categories and actions, including text input actions and destructive actions, and registering them at launch.

When to use it

Use when implementing, reviewing, or debugging push notifications in Swift apps, including:

• requesting user permission
• registering for remote notifications
• handling notification payloads (local and remote)
• configuring categories and actions
• creating rich notification content and attachments
• debugging delivery, background processing, and notification behavior
• working with alerts, badges, sounds, background pushes, or user notification permissions

What it can touch

• Code samples reference UserNotifications APIs and APNs handling in Swift
• File names and tool names are quoted exactly as in the skill text: UNUserNotificationCenter, registerForRemoteNotifications(), didRegisterForRemoteNotificationsWithDeviceToken, UIBackgroundFetchResult, UNMutableNotificationContent, UNTimeIntervalNotificationTrigger, UNCalendarNotificationTrigger, UNLocationNotificationTrigger, UNNotificationRequest, UNNotificationCategory, UNNotificationAction, UNTextInputNotificationAction, UNUserNotificationCenterDelegate, NotificationDelegate, DeepLinkRouter, and related identifiers like MESSAGE_CATEGORY, REPLY_ACTION, etc.

Caveats

• The description specifies targets (iOS 26+ with Swift 6.3) with backward compatibility to iOS 16 unless noted.
• It notes that provisional and critical alerts require special entitlements or prompts.
• It emphasizes that background pushes are low priority, throttled, and not guaranteed, with proper handling in didReceiveRemoteNotification using UIBackgroundFetchResult.
• Service extension behavior requires mutable-content: 1 and handling of content updates on all success/failure/timeout paths; silent pushes do not trigger service extensions.
• Localization uses localization keys within the aps payload.
• Deep linking relies on a shared observable router pattern to route taps to the correct screen.