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
| Symptom / Task |
Reference |
HealthKit framework model, HKHealthStore, data types, sample vs characteristic data |
See skills/fundamentals.md |
Capability setup, requestAuthorization, purpose strings, read-asymmetry, privacy |
See skills/authorization-and-privacy.md |
HKSampleQuery, Swift Concurrency query APIs, HKStatisticsCollectionQuery, sample writes |
See skills/queries.md |
Anchored queries, observer queries, HKDeletedObject, background-delivery entitlement |
See skills/sync-and-background.md |
HKWorkoutSession, HKLiveWorkoutBuilder, recovery, multi-device, iOS/iPadOS/watchOS workout tracking |
See skills/workouts.md |
Workout zones (heart-rate/power effort bands), live + retrospective OS27 |
See skills/workouts.md |
| WorkoutKit custom/planned workouts, scheduling, swimming workouts, previewing |
See skills/workoutkit.md |
State of Mind, Medications API, symptom logging, menopausal state, wellbeing APIs OS27 |
See skills/wellbeing-and-medications.md |
| Health Records (FHIR), Mobility Health App, motion-based health |
See skills/clinical-and-mobility.md |
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.md is the canonical example
SwiftUI
- Charts rendering for health data → See axiom-swiftui
@Observable view 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
HKWorkoutSession lifecycle, 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
digraph health {
start [label="HealthKit / workout task" shape=ellipse];
what [label="What area?" shape=diamond];
start -> what;
what -> "skills/fundamentals.md" [label="framework basics, data types"];
what -> "skills/authorization-and-privacy.md" [label="permissions, purpose strings, privacy"];
what -> "skills/queries.md" [label="reading data, rollups, writes"];
what -> "skills/sync-and-background.md" [label="change tracking, background delivery"];
what -> "skills/workouts.md" [label="HKWorkoutSession, live workouts"];
what -> "skills/workoutkit.md" [label="planned/custom workouts"];
what -> "skills/wellbeing-and-medications.md" [label="State of Mind, Medications"];
what -> "skills/clinical-and-mobility.md" [label="Health Records, Mobility"];
what -> "axiom-watchos" [label="watch-specific presentation"];
what -> "axiom-concurrency" [label="general actor isolation rules"];
what -> "axiom-swiftui" [label="Charts, data visualization"];
}
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
1---2name: axiom-health3description: 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.4license: MIT5---6
7# HealthKit and WorkoutKit
8
9**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.**
10
11## Quick Reference
12
13| Symptom / Task | Reference |
14|----------------|-----------|
15| HealthKit framework model, `HKHealthStore`, data types, sample vs characteristic data | See `skills/fundamentals.md` |
16| Capability setup, `requestAuthorization`, purpose strings, read-asymmetry, privacy | See `skills/authorization-and-privacy.md` |
17| `HKSampleQuery`, Swift Concurrency query APIs, `HKStatisticsCollectionQuery`, sample writes | See `skills/queries.md` |
18| Anchored queries, observer queries, `HKDeletedObject`, `background-delivery` entitlement | See `skills/sync-and-background.md` |
19| `HKWorkoutSession`, `HKLiveWorkoutBuilder`, recovery, multi-device, iOS/iPadOS/watchOS workout tracking | See `skills/workouts.md` |
20| Workout zones (heart-rate/power effort bands), live + retrospective `OS27` | See `skills/workouts.md` |
21| WorkoutKit custom/planned workouts, scheduling, swimming workouts, previewing | See `skills/workoutkit.md` |
22| State of Mind, Medications API, symptom logging, menopausal state, wellbeing APIs `OS27` | See `skills/wellbeing-and-medications.md` |
23| Health Records (FHIR), Mobility Health App, motion-based health | See `skills/clinical-and-mobility.md` |
24
25## Cross-Suite Routes
26
27These topics overlap with HealthKit/WorkoutKit but live in separate suites:
28
29#### watchOS presentation
30- Watch-specific workout presentation (Always On, Smart Stack), complication surfaces → See axiom-watchos
31- Workout app structure on Apple Watch → See axiom-watchos (`skills/platform-basics.md`)
32
33#### Concurrency
34- Swift 6 concurrency, actors, Sendable → See axiom-concurrency
35- HealthKit queries bridging to Swift Concurrency → `skills/queries.md` is the canonical example
36
37#### SwiftUI
38- Charts rendering for health data → See axiom-swiftui
39- `@Observable` view models for health data → See axiom-swiftui
40
41#### Data and sync
42- General cross-platform sync patterns (CloudKit, GRDB) → See axiom-data
43- HealthKit anchored/observer queries as a generalizable sync mechanism → `skills/sync-and-background.md`
44
45#### Security and privacy
46- Keychain storage, encryption, data-protection entitlements → See axiom-security
47
48## Conflict Resolution
49
50**axiom-health vs axiom-watchos**: For workout apps on Apple Watch:
511. **Use axiom-health** for `HKWorkoutSession` lifecycle, `HKLiveWorkoutBuilder`, recovery APIs, multi-device mirroring — these are HealthKit concepts, not watch concepts
522. **Use axiom-watchos** for watch-specific presentation: Always On display, Smart Stack placement, watchOS background mode coordination
533. **Both apply** for a watch-native workout app — start with axiom-health for session lifecycle, then axiom-watchos for presentation
54
55**axiom-health vs axiom-concurrency**: For HealthKit query patterns:
561. **Use axiom-health** for which query type to choose and HealthKit-specific gotchas
572. **Use axiom-concurrency** for general Swift 6 actor isolation rules that apply to query callbacks
58
59**axiom-health vs axiom-data**: For change-tracked data synchronization:
601. **Use axiom-health** for `HKAnchoredObjectQuery`, `HKObserverQuery`, `HKDeletedObject`
612. **Use axiom-data** for application-level data sync across devices (CloudKit, GRDB, SwiftData)
62
63## Decision Tree
64
65```dot
66digraph health {
67 start [label="HealthKit / workout task" shape=ellipse];
68 what [label="What area?" shape=diamond];
69
70 start -> what;
71 what -> "skills/fundamentals.md" [label="framework basics, data types"];
72 what -> "skills/authorization-and-privacy.md" [label="permissions, purpose strings, privacy"];
73 what -> "skills/queries.md" [label="reading data, rollups, writes"];
74 what -> "skills/sync-and-background.md" [label="change tracking, background delivery"];
75 what -> "skills/workouts.md" [label="HKWorkoutSession, live workouts"];
76 what -> "skills/workoutkit.md" [label="planned/custom workouts"];
77 what -> "skills/wellbeing-and-medications.md" [label="State of Mind, Medications"];
78 what -> "skills/clinical-and-mobility.md" [label="Health Records, Mobility"];
79 what -> "axiom-watchos" [label="watch-specific presentation"];
80 what -> "axiom-concurrency" [label="general actor isolation rules"];
81 what -> "axiom-swiftui" [label="Charts, data visualization"];
82}
83```
84
85## Resources
86
87**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
88
89**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
90
91**Skills**: axiom-watchos, axiom-concurrency, axiom-swiftui, axiom-data, axiom-security
charleswiltgen