Handles CloudKit and iCloud sync for iOS and macOS apps. You'll reach for this when implementing record CRUD, queries, subscriptions, or when setting up CKSyncEngine for automatic conflict resolution and change tracking. Covers the full stack from container setup and custom zones to SwiftData integration and iCloud Drive file coordination. The CKSyncEngine section is solid if you're on iOS 17+, it's the modern approach that handles retry logic and push notifications for you. Includes practical error handling patterns for network failures and quota limits, plus a conflict resolution guide. Targets Swift 6.3 but notes backward compatibility where it matters.
npx skills add https://github.com/dpearson2699/swift-ios-skills --skill cloudkit