watchos · diff
git:20260927.027656f to git:20261012.0cd6b32
8 added, 6 removed. Audit A to A.
---
name: watchos
description: Use when building Apple Watch apps — complications, workouts, HealthKit, or iPhone-Watch connectivity.
versions:
watchos: 27
user-invocable: false
references: references/complications.md, references/workouts.md, references/watch-connectivity.md
related-skills: swift-core, swiftui-core, ios, mcp-tools
---
<objective>
Covers watchOS-specific development for Apple Watch: watch-face complications for glanceable data, workout sessions and fitness tracking, HealthKit access to health metrics, and Watch Connectivity for iPhone-Watch sync.
- Includes design considerations specific to the platform — small display with large touch targets, glanceable information with minimal text, Digital Crown scrolling/input, Force Touch on older watches, swipe/tap gestures, and battery-conscious background work.
+ Includes design considerations specific to the platform — small display with large touch targets, glanceable information with minimal text, Digital Crown scrolling/input, swipe/tap gestures, and battery-conscious background work.
Best practices: keep information glanceable, use large tap targets, minimize text input, drive watch-face updates through complications, use efficient background refresh, and always validate on real hardware since the simulator behaves differently.
</objective>
# watchOS Platform
watchOS-specific development for Apple Watch experiences.
## Agent Workflow (MANDATORY)
Before ANY implementation, spawn 3 agents in parallel, one `Agent` call each with a `name`:
1. **fuse-ai-pilot:explore-codebase** - Analyze existing watchOS patterns
2. **fuse-ai-pilot:research-expert** - Verify latest watchOS 27 docs via Context7/Exa
3. **mcp__apple-docs__search_apple_docs** - Check watchOS patterns
After implementation, run **fuse-ai-pilot:sniper** for validation.
---
## Overview
### When to Use
- Building Apple Watch apps
- Creating watch face complications
- Workout and fitness tracking
- Health data access (HealthKit)
- iPhone-Watch communication
### Why watchOS Skill
| Feature | Benefit |
|---------|---------|
| Complications | Glanceable data on watch face |
| Workouts | Fitness and health tracking |
| HealthKit | Access health metrics |
| Connectivity | Sync with iPhone |
---
## Reference Guide
| Need | Reference |
|------|-----------|
| Watch face complications | [complications.md](references/complications.md) |
| Workout sessions, HealthKit | [workouts.md](references/workouts.md) |
| iPhone ↔ Watch sync | [watch-connectivity.md](references/watch-connectivity.md) |
---
## Design Considerations
### Screen Size
- - Small display, large touch targets
- - Glanceable information
- - Minimal text, clear icons
+ - Small display; controls 44x44 pt default, 28x28 pt minimum
+ - Text: 16 pt default, 12 pt minimum; support enlargement to at least 140%
+ - Glanceable information, minimal text, clear icons
+ Source: https://developer.apple.com/design/human-interface-guidelines/accessibility
+
### Interactions
- - Digital Crown for scrolling/input
- - Force Touch (older watches)
+ - Digital Crown for scrolling/input ([HIG](https://developer.apple.com/design/human-interface-guidelines/digital-crown))
- Gestures: swipe, tap
+ - Complications and Smart Stack are WidgetKit accessory widgets (see `swiftui-core/references/hig-system-surfaces.md`)
### Battery
- Minimize background work
- Use complications for updates
- Efficient data transfer
---
## Best Practices
1. **Glanceable** - Quick information access
2. **Large targets** - Easy tapping
3. **Minimal input** - Reduce typing
4. **Complications** - Update watch face data
5. **Background refresh** - Efficient updates
6. **Test on device** - Simulator differs from hardware