AIエージェントでiOSアプリを構築する：実践者向けガイド

# Check Xcode version
xcodebuild -version
# Expected: Xcode 26.3 or later (26.5+ recommended)

# Check available simulators
xcrun simctl list devices available
# Expected: at least one iPhone simulator

# Verify xcrun mcpbridge is available
xcrun mcpbridge --help
# Expected: usage information (not "command not found")

# Install Claude Code (if not already installed)
claude --version  # verify installation

# Add XcodeBuildMCP (59 tools — builds, tests, simulators, debugging)
claude mcp add XcodeBuildMCP \
  -s user \
  -e XCODEBUILDMCP_SENTRY_DISABLED=true \
  -- npx -y xcodebuildmcp@latest mcp

# Add Apple Xcode MCP (20 tools — file ops, diagnostics, Swift REPL, previews)
claude mcp add --transport stdio xcode \
  -s user -- xcrun mcpbridge

xcodebuildmcp init
# Or without a global install:
npx -y xcodebuildmcp@latest init

You: Add a new SettingsView with toggles for notifications and haptic feedback.
     Use the existing Settings.swift pattern from TimerManager.
     Build for simulator after implementation and fix any errors.

Claude: [reads Settings.swift, TimerManager.swift, existing views]
        [creates SettingsView.swift]
        [calls build_sim via MCP]
        [reads structured error: missing import HealthKit]
        [fixes import]
        [calls build_sim again — success, 0 errors, 1 warning]
        [calls test_sim — all tests pass]

# Add Apple Xcode MCP to Codex
codex mcp add xcode -- xcrun mcpbridge

# Add XcodeBuildMCP to Codex
codex mcp add XcodeBuildMCP -- npx -y xcodebuildmcp@latest mcp

# Option 1: Via npx (recommended — always uses latest version)
claude mcp add XcodeBuildMCP \
  -s user \
  -e XCODEBUILDMCP_SENTRY_DISABLED=true \
  -- npx -y xcodebuildmcp@latest mcp

# Option 2: Via Homebrew (pinned version, manual updates)
brew install xcodebuildmcp
claude mcp add XcodeBuildMCP \
  -s user \
  -e XCODEBUILDMCP_SENTRY_DISABLED=true \
  -- xcodebuildmcp mcp

# Option 3: Project-scoped (omit -s user)
claude mcp add XcodeBuildMCP \
  -e XCODEBUILDMCP_SENTRY_DISABLED=true \
  -- npx -y xcodebuildmcp@latest mcp

# Standard installation (global)
claude mcp add --transport stdio xcode \
  -s user -- xcrun mcpbridge

# For Codex CLI
codex mcp add xcode -- xcrun mcpbridge

┌─────────────────────────────────────────────────────────────────┐
│                     MCP TOOL COVERAGE                           │
├─────────────────────────────────────────────────────────────────┤
│                                                                 │
│  XcodeBuildMCP (59 tools)        Apple Xcode MCP (20 tools)    │
│  ┌─────────────────────┐         ┌─────────────────────┐       │
│  │ Standalone           │         │ Requires Xcode      │       │
│  │ (no Xcode process)  │         │ (XPC bridge)        │       │
│  │                     │         │                     │       │
│  │ ✓ Simulators        │  BOTH   │ ✓ Documentation     │       │
│  │ ✓ Real devices      │ ┌─────┐ │ ✓ Swift REPL        │       │
│  │ ✓ LLDB debugging    │ │Build│ │ ✓ SwiftUI previews  │       │
│  │ ✓ UI automation     │ │Test │ │ ✓ Live diagnostics  │       │
│  │ ✓ Project scaffold  │ └─────┘ │ ✓ Analyzer issues   │       │
│  │ ✓ Screenshot        │         │                     │       │
│  └─────────────────────┘         └─────────────────────┘       │
│                                                                 │
└─────────────────────────────────────────────────────────────────┘

# List all configured MCP servers
claude mcp list

# Expected output includes:
# XcodeBuildMCP: npx -y xcodebuildmcp@latest mcp - Connected
# xcode: xcrun mcpbridge - Connected

## Build & Test — Always Use MCP

Prefer MCP tools over raw shell commands for ALL build operations:

- **Build**: `build_sim` / `build_device` (NOT `xcodebuild` via Bash)
- **Test**: `test_sim` / `test_device` (NOT `xcodebuild test` via Bash)
- **Simulators**: `list_sims`, `boot_sim`, `open_sim` (NOT `xcrun simctl` via Bash)
- **Debug**: `debug_attach_sim`, `debug_stack`, `debug_variables`
- **Apple docs**: `DocumentationSearch` (NOT WebSearch for Apple APIs)
- **Swift verification**: `ExecuteSnippet` (NOT `swift` via Bash)
- **Previews**: `RenderPreview` for headless SwiftUI verification

MCP returns structured JSON. Bash returns unstructured text.
Structured data means fewer tokens consumed and better error diagnosis.

# Return - Zen Focus Timer

**Bundle ID:** `com.941apps.Return`
**Target:** iOS 26+ / macOS Tahoe / watchOS 26+ / tvOS 26+
**Architecture:** SwiftUI with @Observable pattern, companion Watch and TV apps
**Swift version:** 6.2
**Minimum deployment:** iOS 26.0

## File Structure

```
Return/
├── ReturnApp.swift              # App entry, dark mode enforcement
├── ContentView.swift            # Main timer view with theme backgrounds
├── TimerManager.swift           # Timer state, logic, and repeat handling
├── AudioManager.swift           # Sound playback with AVAudioPlayer
├── Settings.swift               # Centralized settings with validation
├── SettingsSheet.swift          # Settings UI
├── HealthKitManager.swift       # Mindful session logging + cross-device sync
├── LiveActivityManager.swift    # Lock Screen/Dynamic Island
├── Theme.swift                  # Theme definitions
├── ThemeManager.swift           # Theme state management
├── VideoBackgroundView.swift    # AVPlayer video backgrounds
├── GlassTextShape.swift         # Core Text glyph paths for glass effect
├── GlassTimerText.swift         # Timer text with glass material
└── Constants.swift              # App constants
```

## Build & Test

Build for iOS simulator:
```bash
xcodebuild -scheme Return -destination 'platform=iOS Simulator,name=iPhone 16 Pro' build
```

Run tests:
```bash
xcodebuild -scheme Return -destination 'platform=iOS Simulator,name=iPhone 16 Pro' test
```

Run tvOS tests:
```bash
xcodebuild -scheme ReturnTV -destination 'platform=tvOS Simulator,name=Apple TV' test
```

**Prefer MCP tools** (`build_sim`, `test_sim`) over these raw commands.
MCP returns structured JSON with categorized errors.

## Key Patterns

### Observable Architecture
- ALL view models use `@Observable` (NEVER `ObservableObject`)
- ALL navigation uses `NavigationStack` (NEVER `NavigationView`)
- State management via `@Observable` classes with `@MainActor` isolation

### Settings Pattern
- Centralized `Settings.shared` singleton
- All settings bounded to valid ranges with validation
- Sound names validated against whitelist
- Thread-safe access via @MainActor

### Audio System
- `AVAudioPlayer` with `.playback` category (plays in silent mode)
- Silent audio loop for background execution
- Bell playback with completion callbacks and token-based staleness

## Rules

- **NEVER modify .pbxproj files** — create Swift files, then I will add them to Xcode manually
- **NEVER modify .xcodeproj/ contents directly**
- **NEVER add new package dependencies** without asking first
- **NEVER change the deployment target**
- **NEVER modify entitlements files** unless explicitly asked
- **NEVER use NavigationView** — always NavigationStack
- **NEVER use ObservableObject** — always @Observable
- **NEVER use @StateObject** — always @State with @Observable

## HealthKit Configuration

- Entitlement: `com.apple.developer.healthkit`
- Info.plist keys:
  - `NSHealthShareUsageDescription`: "Return reads your mindful minutes..."
  - `NSHealthUpdateUsageDescription`: "Return logs meditation sessions..."
- Category types: `HKCategoryType(.mindfulSession)`
- Authorization checked on every write (user can revoke at any time)
- HealthKit is unavailable on tvOS — guard with `#if canImport(HealthKit)`

## SwiftData Models

### Model Relationships
- `GroceryList` has many `GroceryItem` (cascade delete)
- `GroceryItem` belongs to one `GroceryList`
- `GroceryItem` has optional `Category`

### Model Container Setup
- Configured in App struct with `modelContainer(for:)`
- Schema versioning: currently V2
- Migration plan: `GroceryMigrationPlan` handles V1 → V2

### Queries
- `@Query(sort: \GroceryItem.name)` for sorted fetches
- `@Query(filter: #Predicate { !$0.isCompleted })` for active items
- Always use `@Query` in views, `modelContext.fetch()` in managers

## SpriteKit Scene Hierarchy

```
GameScene (SKScene)
├── backgroundLayer (SKNode, zPosition: -100)
│   └── StarfieldNode (custom, parallax scrolling)
├── gameLayer (SKNode, zPosition: 0)
│   ├── playerShip (PlayerNode, zPosition: 10)
│   ├── enemyContainer (SKNode, zPosition: 5)
│   └── bulletPool (SKNode, zPosition: 8)
├── effectsLayer (SKNode, zPosition: 50)
│   └── ParticleManager (manages explosion/trail emitters)
└── hudLayer (SKNode, zPosition: 100)
    ├── scoreLabel (SKLabelNode)
    └── healthBar (HealthBarNode)
```

- Physics categories defined in `PhysicsCategory.swift` as bitmasks
- Contact detection via `didBegin(_ contact:)` on GameScene
- Bullet pooling: pre-allocate 50, recycle via `removeFromParent()` + re-add

## Metal Pipeline

- Render pipeline: `MetalView` → `Renderer` → `ShaderLibrary`
- Compute pipeline: `AudioAnalyzer` → compute shader → texture output
- Shared uniforms struct: `Uniforms` in `ShaderTypes.h` (bridged to Swift)
- Frame timing: `CADisplayLink` drives render loop
- Buffer triple-buffering: 3 in-flight frames with semaphore

### Shader Files
- `Shaders.metal` — Main render shaders (vertex + fragment)
- `Compute.metal` — Audio analysis compute kernel
- `PostProcess.metal` — Bloom and color grading

### DO NOT modify Metal shaders without testing on device.
Simulator Metal is not representative of device GPU behavior.

# Banana List - Grocery List App

**Bundle ID:** `com.941apps.BananaList`
**Target:** iOS 26+
**Architecture:** SwiftUI + SwiftData + iCloud Drive sync
**Swift version:** 6.2
**Minimum deployment:** iOS 26.0

## Core Features

- Grocery lists with items, categories, and quantities
- iCloud Drive sync via SwiftData CloudKit integration
- Custom MCP server exposing list data to Claude Desktop
- Liquid Glass design system
- Haptic feedback on interactions
- Share sheets for list sharing

## File Structure

```
BananaList/
├── BananaListApp.swift           # App entry, model container setup
├── Models/
│   ├── GroceryList.swift         # @Model: list with name, items, color
│   ├── GroceryItem.swift         # @Model: item with name, quantity, category, isCompleted
│   ├── Category.swift            # @Model: user-defined categories
│   └── SampleData.swift          # Preview and test data
├── Views/
│   ├── ListsView.swift           # Main list of grocery lists
│   ├── ListDetailView.swift      # Items within a list
│   ├── ItemRow.swift             # Single item row with swipe actions
│   ├── AddItemSheet.swift        # New item form
│   ├── CategoryPicker.swift      # Category selection with create-new
│   └── SettingsView.swift        # App settings
├── Managers/
│   ├── CloudSyncManager.swift    # iCloud Drive sync status and conflict resolution
│   └── HapticManager.swift       # UIImpactFeedbackGenerator wrapper
├── MCP/
│   ├── MCPServer.swift           # MCP server for Claude Desktop integration
│   ├── ListTools.swift           # MCP tools: list CRUD operations
│   └── ItemTools.swift           # MCP tools: item CRUD operations
└── Extensions/
    ├── Color+Extensions.swift    # Custom color definitions
    └── View+Extensions.swift     # Reusable view modifiers
```

## SwiftData Models

### Relationships
- `GroceryList` has many `GroceryItem` (cascade delete)
- `GroceryItem` belongs to one `GroceryList` (required)
- `GroceryItem` has optional `Category`
- `Category` has many `GroceryItem` (nullify on delete)

### Container Setup
```swift
@main
struct BananaListApp: App {
    var body: some Scene {
        WindowGroup {
            ListsView()
        }
        .modelContainer(for: [GroceryList.self, GroceryItem.self, Category.self])
    }
}
```

### Query Patterns
- Lists: `@Query(sort: \GroceryList.name) var lists: [GroceryList]`
- Active items: `@Query(filter: #Predicate { !$0.isCompleted })`
- By category: filter in-memory after fetch (SwiftData predicate limitations)

## Build & Test

```bash
xcodebuild -scheme BananaList -destination 'platform=iOS Simulator,name=iPhone 16 Pro' build
xcodebuild -scheme BananaList -destination 'platform=iOS Simulator,name=iPhone 16 Pro' test
```

Prefer MCP tools (`build_sim`, `test_sim`) over raw commands.

## Key Patterns

### Observable + SwiftData
- SwiftData `@Model` classes are automatically Observable
- DO NOT add `@Observable` to `@Model` classes (redundant, causes warnings)
- Use `@Bindable` for two-way bindings to model properties in forms
- Use `@Query` in views, `modelContext.fetch()` in non-view code

### iCloud Sync
- Automatic via SwiftData CloudKit integration
- Conflict resolution: last-write-wins (CloudKit default)
- Sync status exposed via `CloudSyncManager.shared.syncState`
- Test sync by running on two simulators with same iCloud account

### MCP Server Architecture
- Runs as a local WebSocket server on port 8765
- Exposes 6 tools: listAll, getList, createList, addItem, completeItem, deleteItem
- Claude Desktop connects via MCP config in `~/.config/claude-desktop/config.json`

## Rules

- NEVER modify .pbxproj or .xcodeproj contents
- NEVER change the model schema without updating SampleData.swift
- NEVER use `ObservableObject` — SwiftData models are already Observable
- NEVER use `@StateObject` — use `@State` with `@Observable` classes
- NEVER use `NavigationView` — always `NavigationStack`
- NEVER add `@Observable` macro to `@Model` classes
- ALWAYS use `@Bindable` for form bindings to model properties
- ALWAYS test iCloud sync changes on two simulator instances

# Reps - Workout Tracking

**Bundle ID:** `com.941apps.Reps`
**Target:** iOS 26+
**Architecture:** SwiftUI + SwiftData
**Swift version:** 6.2

## File Structure

```
Reps/
├── RepsApp.swift              # App entry, model container
├── Models/
│   ├── Workout.swift          # @Model: workout with exercises, date, duration
│   ├── Exercise.swift         # @Model: exercise with sets, reps, weight
│   └── ExerciseTemplate.swift # @Model: saved exercise definitions
├── Views/
│   ├── WorkoutListView.swift  # Main list of workouts
│   ├── WorkoutDetailView.swift # Exercises within a workout
│   ├── ExerciseRow.swift      # Single exercise with inline editing
│   ├── AddExerciseSheet.swift # Exercise selection from templates
│   ├── NewWorkoutView.swift   # Start new workout flow
│   └── StatsView.swift        # Progress charts and summaries
├── Managers/
│   └── WorkoutTimer.swift     # Active workout timer
└── Extensions/
    └── Date+Extensions.swift  # Formatting helpers
```

## Build & Test

```bash
xcodebuild -scheme Reps -destination 'platform=iOS Simulator,name=iPhone 16 Pro' build
xcodebuild -scheme Reps -destination 'platform=iOS Simulator,name=iPhone 16 Pro' test
```

## SwiftData Relationships

- `Workout` has many `Exercise` (cascade delete)
- `Exercise` has optional `ExerciseTemplate`
- `ExerciseTemplate` standalone (nullify on exercise delete)

## Rules

- NEVER modify .pbxproj
- NEVER use ObservableObject — use @Observable
- NEVER use NavigationView — use NavigationStack
- @Model classes are already Observable — do not add @Observable macro
- Use @Bindable for form bindings to model properties

# Starfield Destroyer - Space Shooter

**Bundle ID:** `com.941apps.StarfieldDestroyer`
**Target:** iOS 26+
**Architecture:** SpriteKit + Metal post-processing + Game Center
**Swift version:** 6.2

## Game Overview

99 levels across 3 galaxies. 8 unlockable ships with different stats.
Game Center leaderboards and achievements. Metal shader post-processing
for bloom and screen effects.

## File Structure

```
StarfieldDestroyer/
├── StarfieldDestroyerApp.swift    # App entry, Game Center auth
├── GameScene.swift                # Main game scene, update loop
├── MenuScene.swift                # Title screen, ship selection
├── Entities/
│   ├── PlayerShip.swift           # Player node with physics, weapons, shields
│   ├── EnemyShip.swift            # Enemy base class with AI behaviors
│   ├── Bullet.swift               # Bullet pool node
│   ├── PowerUp.swift              # Collectible power-ups
│   └── Boss.swift                 # Boss enemies (levels 33, 66, 99)
├── Systems/
│   ├── LevelManager.swift         # Level progression, wave spawning
│   ├── PhysicsCategory.swift      # UInt32 bitmask categories
│   ├── CollisionHandler.swift     # Contact delegate methods
│   ├── ScoreManager.swift         # Score tracking, multipliers
│   ├── ParticleManager.swift      # Explosion, trail, shield emitters
│   └── AudioManager.swift         # Sound effects, background music
├── UI/
│   ├── HUDNode.swift              # Score, health, level display
│   ├── ShipSelectView.swift       # SwiftUI ship selection (UIHostingController)
│   ├── GameOverView.swift         # Game over screen with score submission
│   └── PauseMenu.swift            # Pause overlay
├── Metal/
│   ├── MetalRenderer.swift        # Post-processing render pipeline
│   ├── BloomShader.metal          # Bloom post-process effect
│   └── ShaderTypes.h              # Shared uniforms (bridging header)
├── Data/
│   ├── ShipData.swift             # 8 ship definitions (speed, damage, shields)
│   ├── LevelData.swift            # 99 level configurations
│   └── AchievementData.swift      # Game Center achievement definitions
└── GameCenterManager.swift        # Leaderboard/achievement submission
```

## SpriteKit Scene Hierarchy

```
GameScene (SKScene)
├── backgroundLayer (zPosition: -100)
│   └── StarfieldNode (parallax scrolling, 3 layers)
├── gameLayer (zPosition: 0)
│   ├── playerShip (zPosition: 10)
│   ├── enemyContainer (zPosition: 5)
│   ├── bulletPool (zPosition: 8) — pre-allocated 50 bullets
│   └── powerUpContainer (zPosition: 3)
├── effectsLayer (zPosition: 50)
│   └── ParticleManager (explosion + trail emitters)
└── hudLayer (zPosition: 100)
    ├── scoreLabel (SKLabelNode)
    ├── healthBar (custom SKShapeNode)
    └── levelLabel (SKLabelNode)
```

## Physics Categories

```swift
struct PhysicsCategory {
    static let none:      UInt32 = 0
    static let player:    UInt32 = 0b1        // 1
    static let enemy:     UInt32 = 0b10       // 2
    static let bullet:    UInt32 = 0b100      // 4
    static let powerUp:   UInt32 = 0b1000     // 8
    static let shield:    UInt32 = 0b10000    // 16
    static let bossBullet:UInt32 = 0b100000   // 32
}

// Contact pairs:
// player + enemy → damage
// player + powerUp → collect
// bullet + enemy → destroy
// player + bossBullet → damage
```

## Game State Machine

```
.menu → .playing → .paused → .playing
                 → .gameOver → .menu
                 → .bossIntro → .playing
                 → .levelComplete → .playing (next level)
```

## Metal Post-Processing

- Bloom shader: `BloomShader.metal` — multi-pass Gaussian blur + additive blend
- Uniforms: `PostProcessUniforms { float intensity; float threshold; float2 resolution; }`
- Applied after SpriteKit renders each frame via `SKView.presentScene(:transition:)`
- DO NOT modify Metal shaders without testing on device

## Build & Test

```bash
xcodebuild -scheme StarfieldDestroyer -destination 'platform=iOS Simulator,name=iPhone 16 Pro' build
xcodebuild -scheme StarfieldDestroyer -destination 'platform=iOS Simulator,name=iPhone 16 Pro' test
```

## Rules

- NEVER modify .pbxproj
- NEVER modify PhysicsCategory bitmasks (breaks all collision detection)
- NEVER change the scene hierarchy z-ordering without understanding render order
- NEVER modify ShaderTypes.h without updating both Swift and Metal references
- Add new enemies by subclassing EnemyShip, not by modifying it
- Bullet pooling: recycle via removeFromParent() + re-add, never allocate new
- Game Center: always check isAuthenticated before submitting scores

# amp97 - Audio Visualizer

**Bundle ID:** `com.941apps.amp97`
**Target:** iOS 26+
**Architecture:** Metal render pipeline + AVAudioEngine analysis
**Swift version:** 6.2

## Architecture

```
Audio Input (microphone/file)
    → AVAudioEngine tap
    → FFT (vDSP)
    → Frequency/amplitude buffers
    → Metal compute shader (analysis)
    → Metal render pipeline (visualization)
    → CADisplayLink (60fps)
    → MTKView
```

## File Structure

```
amp97/
├── amp97App.swift               # App entry
├── Audio/
│   ├── AudioEngine.swift        # AVAudioEngine setup, tap installation
│   ├── FFTProcessor.swift       # vDSP FFT, frequency bin extraction
│   ├── AudioBuffer.swift        # Ring buffer for audio data
│   └── MicrophoneManager.swift  # Microphone permission, session config
├── Rendering/
│   ├── MetalView.swift          # MTKView wrapper for SwiftUI
│   ├── Renderer.swift           # Main render loop, pipeline state
│   ├── ShaderLibrary.swift      # Compiled shader management
│   ├── BufferManager.swift      # Triple-buffered uniform updates
│   └── TextureManager.swift     # Offscreen render targets
├── Shaders/
│   ├── Shaders.metal            # Vertex + fragment shaders
│   ├── AudioCompute.metal       # Audio analysis compute kernel
│   ├── PostProcess.metal        # Bloom, color grading
│   └── ShaderTypes.h            # Shared uniforms (bridging header)
├── Visualizations/
│   ├── WaveformViz.swift        # Oscilloscope-style waveform
│   ├── SpectrumViz.swift        # Frequency spectrum bars
│   ├── CircularViz.swift        # Radial visualization
│   └── VizSelector.swift        # Visualization switching
├── Views/
│   ├── MainView.swift           # Full-screen viz with overlays
│   ├── ControlsOverlay.swift    # Play/pause, viz selection, gain
│   └── SettingsView.swift       # Audio source, sensitivity
└── Extensions/
    ├── SIMD+Extensions.swift    # Vector math helpers
    └── Color+Metal.swift        # UIColor → float4 conversion
```

## Metal Pipeline

### Uniforms (ShaderTypes.h)
```c
typedef struct {
    float time;
    float2 resolution;
    float audioLevel;       // 0.0-1.0 RMS amplitude
    float frequencyBins[64]; // FFT output, normalized
    float4x4 transform;
} Uniforms;
```

### Render Pipeline
1. Compute pass: AudioCompute.metal processes FFT data → texture
2. Render pass: Shaders.metal reads texture + uniforms → visualization
3. Post-process pass: PostProcess.metal applies bloom → final output

### Buffer Management
- Triple buffering with DispatchSemaphore(value: 3)
- Uniforms updated per-frame on CPU, consumed by GPU 1-2 frames later
- Audio data ring buffer: 4096 samples, lock-free single producer/consumer

## Rules

- NEVER modify ShaderTypes.h without updating BOTH Swift and Metal sides
- NEVER exceed 64 frequency bins (fixed buffer size in shader)
- NEVER test Metal visual output in simulator — device only
- NEVER modify the audio engine tap format (48kHz, mono, float32)
- Triple buffer discipline: always signal semaphore in completion handler
- Audio session: .playAndRecord category with .defaultToSpeaker option

You: Summarize this project. What scheme should I build with?

Claude: [reads CLAUDE.md]
        [calls discover_projs via MCP]
        [calls list_schemes via MCP]

        This is Return, a zen meditation timer for iOS 26+, watchOS, and tvOS.
        Available schemes: Return, ReturnWatch, ReturnTV, ReturnTests.
        Primary scheme for iOS: Return.

You: Build the Return scheme for iOS simulator and report results.

Claude: [calls list_sims — finds iPhone 16 Pro on iOS 26.2]
        [calls boot_sim — boots the simulator]
        [calls build_sim — builds the project]

        Build succeeded. 63 source files compiled.
        2 warnings:
        - HomeView.swift:132 — UIScreen.main deprecated in iOS 26.0
        - LogWaterIntent.swift:61 — Result of try? is unused
        0 errors.

You: Run all tests and report pass/fail.

Claude: [calls test_sim]

        12 tests executed:
        ✓ TimerManagerTests (5/5 passed)
        ✓ SettingsTests (4/4 passed)
        ✓ ConstantsTests (3/3 passed)
        All tests passed.

You: Add a new "Rain" theme to the theme system. Follow the existing
     pattern in Theme.swift and ThemeManager.swift. Include a rain
     ambient sound. Build and test after implementation.

Claude: [reads Theme.swift — understands Theme struct pattern]
        [reads ThemeManager.swift — understands theme registration]
        [reads existing theme definitions]
        [adds Rain theme to Theme.swift following existing pattern]
        [registers Rain theme in ThemeManager.swift]
        [calls build_sim — build succeeds]
        [calls test_sim — all tests pass]

        Added Rain theme:
        - Theme.swift: new `static let rain` with video, cover, ambient
        - ThemeManager.swift: added to `allThemes` array
        - Build: success (0 errors, 2 existing warnings)
        - Tests: 12/12 passed

        Note: You'll need to add rain_ambient.wav to the project
        and add the new Theme.swift changes to the Xcode target manually
        (I did not modify .pbxproj).

Create a SettingsView that matches the existing pattern in SettingsSheet.swift.
Include toggles for:
- Enable haptic feedback (Settings.shared.hapticsEnabled)
- Enable HealthKit logging (Settings.shared.healthKitEnabled)
- Show session history (navigation link to SessionHistoryView)

Use Liquid Glass styling with .glassEffect() on section backgrounds.
Follow the @Observable pattern, not ObservableObject.

Write unit tests for TimerManager covering:
1. Initial state is .stopped
2. start() transitions to .running
3. pause() transitions to .paused
4. reset() returns to .stopped with original duration
5. Timer counts down correctly (test with 3-second duration)

Refactor all views in the Views/ directory to use @Observable instead of
ObservableObject. Update @StateObject to @State, @ObservedObject to direct
property access, and @Published to plain properties.

Boot an iPhone 16 Pro simulator on iOS 26, install the app, and take a screenshot.

{
  "hooks": {
    "PreToolUse": [
      {
        "matcher": "Edit|Write",
        "command": "bash -c 'INPUT=$(cat); FP=$(echo \"$INPUT\" | jq -r \".tool_input.file_path // empty\"); if echo \"$FP\" | grep -qE \"\\.(pbxproj|xcworkspace|xib|storyboard)$|xcodeproj/|xcworkspace/\"; then echo \"BLOCKED: Do not modify Xcode project files. Create Swift files and add to Xcode manually.\" >&2; exit 2; fi'"
      }
    ]
  }
}

{
  "hooks": {
    "PostToolUse": [
      {
        "matcher": "Edit|Write",
        "command": "bash -c 'INPUT=$(cat); FP=$(echo \"$INPUT\" | jq -r \".tool_input.file_path // empty\"); if echo \"$FP\" | grep -qE \"\\.swift$\"; then swiftformat \"$FP\" --quiet 2>/dev/null; fi'"
      }
    ]
  }
}

# .swiftformat
--indent 4
--allman false
--stripunusedargs closure-only
--importgrouping testable-bottom
--header strip

{
  "hooks": {
    "PostToolUse": [
      {
        "matcher": "Edit|Write",
        "command": "bash -c 'INPUT=$(cat); FP=$(echo \"$INPUT\" | jq -r \".tool_input.file_path // empty\"); if echo \"$FP\" | grep -qE \"\\.swift$\"; then swiftlint lint --path \"$FP\" --quiet 2>/dev/null || true; fi'"
      }
    ]
  }
}

{
  "hooks": {
    "PostToolUse": [
      {
        "matcher": "Edit|Write",
        "command": "bash -c 'INPUT=$(cat); FP=$(echo \"$INPUT\" | jq -r \".tool_input.file_path // empty\"); if echo \"$FP\" | grep -qE \"\\.swift$\"; then xcodebuild -scheme Return -destination \"platform=iOS Simulator,name=iPhone 16 Pro\" build 2>&1 | tail -5; fi'"
      }
    ]
  }
}

{
  "hooks": {
    "PreToolUse": [
      {
        "matcher": "Edit|Write",
        "command": "bash -c 'INPUT=$(cat); FP=$(echo \"$INPUT\" | jq -r \".tool_input.file_path // empty\"); if echo \"$FP\" | grep -qE \"\\.entitlements$\"; then echo \"BLOCKED: Do not modify entitlements files without explicit permission.\" >&2; exit 2; fi'"
      }
    ]
  }
}

{
  "hooks": {
    "PreToolUse": [
      {
        "matcher": "Edit|Write",
        "command": "bash -c 'INPUT=$(cat); FP=$(echo \"$INPUT\" | jq -r \".tool_input.file_path // empty\"); if echo \"$FP\" | grep -qE \"\\.(pbxproj|xcworkspace|xib|storyboard|entitlements)$|xcodeproj/|xcworkspace/\"; then echo \"BLOCKED: Do not modify Xcode-managed files. Create Swift files and add manually.\" >&2; exit 2; fi'"
      }
    ],
    "PostToolUse": [
      {
        "matcher": "Edit|Write",
        "command": "bash -c 'INPUT=$(cat); FP=$(echo \"$INPUT\" | jq -r \".tool_input.file_path // empty\"); if echo \"$FP\" | grep -qE \"\\.swift$\"; then swiftformat \"$FP\" --quiet 2>/dev/null; fi'"
      }
    ]
  }
}

// CORRECT — @Observable
@Observable
@MainActor
final class TimerManager {
    var timeRemaining: TimeInterval = 0
    var state: TimerState = .stopped

    func start() {
        state = .running
        // ...
    }
}

// In a view:
struct TimerView: View {
    @State private var timer = TimerManager()

    var body: some View {
        Text(timer.timeRemaining, format: .number)
    }
}

// WRONG — ObservableObject (deprecated pattern)
class TimerManager: ObservableObject {
    @Published var timeRemaining: TimeInterval = 0
    @Published var state: TimerState = .stopped
}

// WRONG — @StateObject (deprecated pattern)
struct TimerView: View {
    @StateObject private var timer = TimerManager()
}

// CORRECT
NavigationStack {
    List(items) { item in
        NavigationLink(value: item) {
            ItemRow(item: item)
        }
    }
    .navigationDestination(for: Item.self) { item in
        ItemDetailView(item: item)
    }
}

// WRONG
NavigationView {
    List(items) { item in
        NavigationLink(destination: ItemDetailView(item: item)) {
            ItemRow(item: item)
        }
    }
}

@Model
final class GroceryItem {
    var name: String
    var quantity: Int
    var isCompleted: Bool
    var category: Category?
    var list: GroceryList?

    init(name: String, quantity: Int = 1) {
        self.name = name
        self.quantity = quantity
        self.isCompleted = false
    }
}

// Actor isolation for shared mutable state
@MainActor
@Observable
final class DataManager {
    var items: [Item] = []

    func loadItems() async throws {
        let fetched = try await api.fetchItems()
        items = fetched  // Safe: @MainActor isolated
    }
}

// Sendable conformance for cross-actor transfers
struct Item: Sendable, Identifiable {
    let id: UUID
    let name: String
    let createdAt: Date
}

// Glass effect on containers
VStack {
    // content
}
.glassEffect()

// Glass effect with tint
Button("Action") { }
    .glassEffect(.regular.tint(.blue))

// Glass effect on navigation bars (automatic in iOS 26)
NavigationStack {
    // content
}
// Navigation bar automatically uses glass material

// Custom glass shapes
RoundedRectangle(cornerRadius: 16)
    .fill(.ultraThinMaterial)
    .glassEffect()

// Always check availability and authorization
import HealthKit

@MainActor
@Observable
final class HealthKitManager {
    private let store = HKHealthStore()
    var isAuthorized = false

    func requestAuthorization() async {
        guard HKHealthStore.isHealthDataAvailable() else { return }

        let types: Set<HKSampleType> = [
            HKQuantityType(.dietaryWater),
            HKCategoryType(.mindfulSession)
        ]

        do {
            try await store.requestAuthorization(toShare: types, read: types)
            isAuthorized = true
        } catch {
            // User denied — do not retry automatically
        }
    }
}

## SpriteKit Rules

- Scene hierarchy is a tree of SKNodes with zPosition ordering
- Physics bodies use category bitmasks (UInt32) for collision detection
- Node pooling: pre-allocate reusable nodes (bullets, particles)
- Never add nodes directly to the scene — use layer nodes for organization
- Update loop: `update(_ currentTime:)` runs every frame — keep it fast
- Actions: use SKAction sequences for animations, not manual property updates
- Textures: use texture atlases for performance (.atlas directories)

## Metal Rules

- Shared types between Swift and Metal go in a bridging header (ShaderTypes.h)
- Triple buffer in-flight frames (semaphore with value 3)
- Test shaders on DEVICE, not simulator (Metal behavior differs)
- Compute shaders: threadgroup size must divide evenly into grid size
- Fragment shaders: output color must be in correct color space (sRGB or linear)
- DO NOT optimize shaders without Instruments GPU profiling data

## Live Activities

- ActivityAttributes defined in `TimerActivityAttributes.swift`
- ActivityKit framework: `import ActivityKit`
- Widget extension: `ReturnWidgets/ReturnLiveActivity.swift`
- Start: `Activity<TimerActivityAttributes>.request(attributes:content:)`
- Update: `activity.update(ActivityContent(state:staleDate:))`
- End: `activity.end(ActivityContent(state:staleDate:), dismissalPolicy:)`
- Push token: register for updates via `activity.pushTokenUpdates`

## Game Center

- Authentication: `GKLocalPlayer.local.authenticateHandler`
- Leaderboards: `GKLeaderboard.submitScore(_:context:player:leaderboardIDs:completionHandler:)`
- Achievements: `GKAchievement.report(_:withCompletionHandler:)` (takes `[GKAchievement]` array)
- Always check `GKLocalPlayer.local.isAuthenticated` before submitting
- Handle authentication failure gracefully (offline play must work)

Shared/
├── MeditationSession.swift    # Data model (all platforms)
├── SessionStore.swift         # iCloud sync (all platforms)
└── SessionHistoryView.swift   # UI (adapts per platform)

Return/                        # iOS-specific
ReturnWatch Watch App/         # watchOS-specific
ReturnTV/                      # tvOS-specific

// HealthKit: available on iOS and watchOS, not tvOS
#if canImport(HealthKit)
import HealthKit
// HealthKit code here
#endif

// ActivityKit: available on iOS only
#if canImport(ActivityKit)
import ActivityKit
// Live Activity code here
#endif

// WatchKit: available on watchOS only
#if os(watchOS)
import WatchKit
// Watch-specific code here
#endif

struct SessionHistoryView: View {
    @Query var sessions: [MeditationSession]

    var body: some View {
        List(sessions) { session in
            SessionRow(session: session)
        }
        #if os(tvOS)
        .focusable()
        #endif
        #if os(iOS)
        .swipeActions {
            Button("Delete", role: .destructive) {
                // delete
            }
        }
        #endif
    }
}

Implement a countdown timer that:
1. Starts from a user-selected duration (10, 20, or 30 minutes)
2. Shows remaining time with a circular progress indicator
3. Plays a bell sound on completion
4. Logs the session to HealthKit as mindful minutes

Build after each change. Fix all errors. Run tests when the build succeeds.
Continue until all tests pass and the build is clean.

Use a subagent to research the best approach for implementing
iCloud key-value store sync for meditation sessions across iOS,
watchOS, and tvOS. Report back with the recommended pattern.

Look at how Settings.swift works in the Return project
(centralized singleton with validation). Apply the same pattern
to create a Settings.swift for the Water project.

# After Claude implements the feature:
codex "Review the changes in the last commit. Focus on Swift 6.2
      concurrency correctness, SwiftData relationship integrity,
      and potential retain cycles. Report issues only — no praise."

# Update @Observable pattern across all projects
for project in BananaList Return Water Reps; do
  cd ~/Projects/$project
  claude -p "Audit all files for any remaining ObservableObject usage.
             Convert to @Observable following the pattern in CLAUDE.md.
             Build and test after changes." --dangerously-skip-permissions
done

import FoundationModels

func budgetFor(prompt: String, reservedReply: Int = 256) async throws -> Int {
    let model = SystemLanguageModel.default
    let promptCost = try await model.tokenCount(for: prompt)
    let budget = model.contextSize - promptCost - reservedReply
    guard budget > 0 else { throw ContextError.promptTooLong }
    return budget
}

┌─────────────┐     ┌─────────────┐     ┌─────────────┐
│    tvOS     │     │    Mac      │     │   Watch     │
│ TVTimerMgr  │     │ TimerMgr    │     │ WatchTimer  │
└──────┬──────┘     └──────┬──────┘     └──────┬──────┘
       │                   │                   │
       └───────────────────┼───────────────────┘
                           │
                           ▼
              ┌────────────────────────┐
              │     SessionStore       │
              │  (iCloud Key-Value)    │
              └───────────┬────────────┘
                          │
                          ▼
              ┌────────────────────────┐
              │  iPhone (on foreground)│
              │  → Write to HealthKit  │
              └────────────────────────┘

You: Here's the next feature for Return: add a "Focus Score" that
     calculates from session duration and consistency. Show it on
     the main timer view. Build and test.

Claude: [reads CLAUDE.md, understands patterns]
        [reads TimerManager.swift, Settings.swift]
        [creates FocusScore.swift — model with calculation logic]
        [creates FocusScoreView.swift — display component]
        [integrates into ContentView.swift]
        [calls build_sim — 1 error: missing import]
        [fixes import]
        [calls build_sim — success]
        [writes FocusScoreTests.swift]
        [calls test_sim — all pass]

---
name: ios-developer
description: iOS development agent with MCP build tools and SwiftUI expertise
tools:
  - XcodeBuildMCP
  - xcode
---

# iOS Developer Agent

You are an iOS development agent for apps targeting iOS 26+ with SwiftUI.

## Architecture Rules
- @Observable for all view models (NEVER ObservableObject)
- NavigationStack for all navigation (NEVER NavigationView)
- SwiftData for persistence
- Swift 6.2 strict concurrency
- @MainActor on all Observable classes

## Build & Test — Always Use MCP

Prefer MCP tools over raw shell commands for ALL build operations:

- **Build**: `build_sim` / `build_device` (NOT `xcodebuild` via Bash)
- **Test**: `test_sim` / `test_device` (NOT `xcodebuild test` via Bash)
- **Simulators**: `list_sims`, `boot_sim`, `open_sim`
- **Debug**: `debug_attach_sim`, `debug_stack`, `debug_variables`
- **Apple docs**: `DocumentationSearch` (NOT WebSearch for Apple APIs)
- **Swift verification**: `ExecuteSnippet` (NOT `swift` via Bash)

MCP returns structured JSON. Bash returns unstructured text.

## File Management Rules
- NEVER modify .pbxproj, .xcodeproj/, .xcworkspace/, .xib, .storyboard
- Create Swift files in the correct directory
- Report files that need manual addition to Xcode targets

## SwiftData Rules
- @Model classes are automatically Observable — do not add @Observable
- Use @Bindable for form bindings to model properties
- Use @Query in views, modelContext.fetch() elsewhere
- Document relationship delete rules

## When You Get Stuck
- Build errors: use `build_sim` via MCP for structured output
- API questions: use `DocumentationSearch` via Apple MCP
- Swift verification: use `ExecuteSnippet` via Apple MCP
- Never guess — verify with tools

# In CLAUDE.md:
## Test Structure

Tests mirror source structure:
- `ReturnTests/TimerManagerTests.swift` tests `TimerManager.swift`
- `ReturnTests/SettingsTests.swift` tests `Settings.swift`
- `ReturnTests/ConstantsTests.swift` tests `Constants.swift`

Test naming: `test_<what>_<condition>_<expected>`
Example: `test_start_whenStopped_transitionsToRunning`

Write unit tests for TimerManager covering:

1. Initial state is .stopped with timeRemaining == selectedDuration
2. start() transitions state to .running
3. pause() from .running transitions to .paused
4. reset() from any state returns to .stopped with original duration
5. start() from .paused resumes (state becomes .running)
6. Edge case: reset() when already stopped is a no-op
7. Edge case: pause() when already paused is a no-op

Follow the existing test pattern in SettingsTests.swift.
Use setUp() to create a fresh TimerManager for each test.

Write tests for TimerManager.

// Agent produces this pattern when guided correctly:
final class TimerManagerTests: XCTestCase {
    var sut: TimerManager!

    @MainActor
    override func setUp() {
        super.setUp()
        sut = TimerManager()
    }

    @MainActor
    func test_start_whenStopped_transitionsToRunning() {
        // Given
        XCTAssertEqual(sut.state, .stopped)

        // When
        sut.start()

        // Then
        XCTAssertEqual(sut.state, .running)
    }

    @MainActor
    func test_timerCountsDown_afterOneSecond() async throws {
        // Given
        sut.selectedDuration = 10
        sut.reset()
        sut.start()

        // When
        try await Task.sleep(for: .seconds(1.1))

        // Then
        XCTAssertLessThanOrEqual(sut.timeRemaining, 9.0)
    }
}

Add snapshot tests for the main timer view in three states:
1. Stopped (showing full duration)
2. Running (showing countdown)
3. Completed (showing 00:00 with completion state)

Use SnapshotTesting library. Create reference images on first run.

Use discover_projs and list_schemes to find the correct scheme name
for this project before building.

## Build
Primary scheme: `Return` (iOS)
Watch scheme: `ReturnWatch` (watchOS)
TV scheme: `ReturnTV` (tvOS)

# Ensure Xcode command line tools are selected
sudo xcode-select -s /Applications/Xcode.app/Contents/Developer

# Verify
xcrun mcpbridge --help

# Exit current session (Ctrl+C or /exit)
# Start fresh
claude

You: List all available MCP tools from XcodeBuildMCP.

xcrun simctl shutdown all
xcrun simctl boot "iPhone 16 Pro"

Shut down all simulators, then boot a fresh iPhone 16 Pro.

{
  "hooks": {
    "PreToolUse": [
      {
        "matcher": "Edit|Write",
        "command": "bash -c 'INPUT=$(cat); FP=$(echo \"$INPUT\" | jq -r \".tool_input.file_path // empty\"); if echo \"$FP\" | grep -qE \"\\.(pbxproj|xcworkspace|xib|storyboard)$|xcodeproj/|xcworkspace/\"; then echo \"BLOCKED: Do not modify Xcode project files.\" >&2; exit 2; fi'"
      }
    ]
  }
}

## Configuration

API base URL and keys are in `Config.xcconfig` (not committed).
Required keys:
- `API_BASE_URL` — Backend server URL
- `API_KEY` — Authentication token

Create `Config.xcconfig` from `Config.xcconfig.template`.

Implement error handling for the HealthKit authorization flow:
1. Check HKHealthStore.isHealthDataAvailable() — show alert if not
2. Request authorization — handle denial gracefully
3. On write failure — retry once, then show error
4. All errors should be user-facing with localized descriptions

Add accessibility labels to all interactive elements in TimerView:
- Timer display: current time remaining
- Start/Pause button: current state and action
- Reset button: "Reset timer"
- Duration picker: selected duration

## Core Data Model Versions
- V1: Initial (GroceryList, GroceryItem)
- V2: Added Category model (current)
- Migration: Lightweight automatic for V1→V2

- NEVER use ObservableObject — use @Observable
- NEVER add @Observable to @Model classes (already Observable)
- NEVER use @StateObject — use @State with @Observable
- NEVER use @ObservedObject — access @Observable properties directly

## Closure Pattern
- Timer callbacks: use `[weak self]` and guard
- NotificationCenter observers: store in `Set<AnyCancellable>` and use `[weak self]`
- Completion handlers: use `[weak self]` for any closure stored beyond the call site

## Concurrency Rule
ALL @Observable classes MUST be @MainActor:
```swift
@Observable
@MainActor
final class SomeManager { }
```

## Navigation Pattern
ALWAYS use value-based navigation:
```swift
NavigationLink(value: item) { ItemRow(item: item) }
.navigationDestination(for: Item.self) { ItemDetailView(item: $0) }
```
NEVER use: `NavigationLink(destination: ItemDetailView(item: item)) { }`

## Simulators
Do NOT hardcode simulator names. Use `list_sims` MCP tool to discover
available devices, then `boot_sim` with the discovered device ID.

## File Placement Rules
- Views → `AppName/Views/`
- Models → `AppName/Models/`
- Managers → `AppName/Managers/`
- Extensions → `AppName/Extensions/`
- Tests → `AppNameTests/`

## Platform Guards
- HealthKit: `#if canImport(HealthKit)` (unavailable on tvOS)
- ActivityKit: `#if canImport(ActivityKit)` (iOS only)
- WatchKit: `#if os(watchOS)`
- UIKit haptics: `#if os(iOS)` (unavailable on tvOS, watchOS uses WKHaptic)

## Architecture Principle
Prefer the simplest solution that handles the requirements.
- Direct implementation over protocol abstraction (unless you have 2+ conforming types)
- Concrete types over generics (unless reuse is proven)
- Extensions on existing types over new wrapper types

# XcodeBuildMCP (59 tools)
claude mcp add XcodeBuildMCP -s user \
  -e XCODEBUILDMCP_SENTRY_DISABLED=true \
  -- npx -y xcodebuildmcp@latest mcp

# Apple Xcode MCP (20 tools)
claude mcp add --transport stdio xcode -s user -- xcrun mcpbridge

# Codex MCP setup
codex mcp add xcode -- xcrun mcpbridge

# Verify
claude mcp list

1. Project identity (bundle ID, target OS, architecture)
2. File structure with annotations
3. Build and test commands
4. Key patterns and rules
5. Prohibitions (NEVER touch .pbxproj)
6. Framework-specific context

{
  "PreToolUse": [{ "matcher": "Edit|Write", "command": "block .pbxproj" }],
  "PostToolUse": [{ "matcher": "Edit|Write", "command": "swiftformat" }]
}

@Observable         (not ObservableObject)
NavigationStack     (not NavigationView)
@State              (not @StateObject)
SwiftData @Model    (not Core Data)
async/await         (not completion handlers)
@MainActor          (on all Observable classes)
.glassEffect()      (Liquid Glass, iOS 26+)

Build:     build_sim          (not xcodebuild via Bash)
Test:      test_sim           (not xcodebuild test via Bash)
Sim:       list_sims/boot_sim (not xcrun simctl via Bash)
Docs:      DocumentationSearch (not WebSearch)
REPL:      ExecuteSnippet     (not swift via Bash)