HealthKit and WorkoutKit
You MUST use this skill for ANY HealthKit or WorkoutKit development including authorization, data queries, background delivery, workout sessions, planned workouts, wellbeing APIs (State of Mind), Medications, and Health Records.
Quick Reference
Cross-Suite Routes
These topics overlap with HealthKit/WorkoutKit but live in separate suites:
watchOS presentation
- Watch-specific workout presentation (Always On, Smart Stack), complication surfaces → See axiom-watchos
- Workout app structure on Apple Watch → See axiom-watchos (
skills/platform-basics.md)
Concurrency
- Swift 6 concurrency, actors, Sendable → See axiom-concurrency
- HealthKit queries bridging to Swift Concurrency →
skills/queries.mdis the canonical example
SwiftUI
- Charts rendering for health data → See axiom-swiftui
@Observableview models for health data → See axiom-swiftui
Data and sync
- General cross-platform sync patterns (CloudKit, GRDB) → See axiom-data
- HealthKit anchored/observer queries as a generalizable sync mechanism →
skills/sync-and-background.md
Security and privacy
- Keychain storage, encryption, data-protection entitlements → See axiom-security
Conflict Resolution
axiom-health vs axiom-watchos: For workout apps on Apple Watch:
- Use axiom-health for
HKWorkoutSessionlifecycle,HKLiveWorkoutBuilder, recovery APIs, multi-device mirroring — these are HealthKit concepts, not watch concepts - Use axiom-watchos for watch-specific presentation: Always On display, Smart Stack placement, watchOS background mode coordination
- Both apply for a watch-native workout app — start with axiom-health for session lifecycle, then axiom-watchos for presentation
axiom-health vs axiom-concurrency: For HealthKit query patterns:
- Use axiom-health for which query type to choose and HealthKit-specific gotchas
- Use axiom-concurrency for general Swift 6 actor isolation rules that apply to query callbacks
axiom-health vs axiom-data: For change-tracked data synchronization:
- Use axiom-health for
HKAnchoredObjectQuery,HKObserverQuery,HKDeletedObject - Use axiom-data for application-level data sync across devices (CloudKit, GRDB, SwiftData)
Decision Tree
Resources
WWDC: 2019-218, 2020-10182, 2020-10184, 2020-10664, 2021-10009, 2021-10287, 2022-10005, 2023-10016, 2023-10023, 2024-10084, 2024-10109, 2025-321, 2025-322
Docs: /healthkit, /healthkit/about-the-healthkit-framework, /healthkit/authorizing-access-to-health-data, /healthkit/protecting-user-privacy, /healthkit/reading-data-from-healthkit, /healthkit/running-queries-with-swift-concurrency, /healthkit/executing-anchored-object-queries, /healthkit/executing-observer-queries, /healthkit/hkworkoutsession, /healthkit/hklivewobuilder, /workoutkit, /healthkit/accessing-health-records
Skills: axiom-watchos, axiom-concurrency, axiom-swiftui, axiom-data, axiom-security



