Build and sharpen a project's domain model. Use when discussing codebase terminology, writing or editing a CONTEXT.md, or recording or editing an ADR.
Use when ANY iOS build fails, test crashes, Xcode misbehaves, or environment issue occurs before debugging code. Covers build failures, compilation errors, dependency conflicts, simulator problems, environment-first diagnostics.
Use when writing ANY async code, actors, threads, or seeing ANY concurrency error. Covers Swift 6 concurrency, @MainActor, Sendable, data races, async/await patterns.
Use when working with ANY data persistence, database, storage, CloudKit, migration, or serialization. Covers SwiftData, Core Data, GRDB, SQLite, CloudKit sync, file storage, Codable, migrations.
Use when making design decisions, implementing HIG patterns, Liquid Glass, SF Symbols, typography, or structuring app entry points and authentication flows.
Use when working with HealthKit, WorkoutKit, health data, workouts, or fitness features on iOS or watchOS. Covers permissions, queries, background delivery, custom workouts, multidevice coordination.
Use when integrating ANY iOS system feature - Siri, Shortcuts, widgets, IAP, localization, privacy, alarms, calendar, reminders, contacts, background tasks, push notifications, timers. Covers App Intents, WidgetKit, StoreKit, EventKit, Contacts.
Use when working with camera, photos, audio, haptics, ShazamKit, or Now Playing. Covers AVCaptureSession, PHPicker, PhotosPicker, AVFoundation, Core Haptics, audio recognition, MediaPlayer, CarPlay, MusicKit.