iOS to Android: Feature Parity Implementation

Use iOS code as the reference to implement the equivalent Android feature. Not a literal translation - understand what the iOS code does, then implement it idiomatically for Android.

Use this when:

• Porting a feature from iOS to Android
• iOS is the "source of truth" for a feature
• Ensuring feature parity between platforms

Key Principle

iOS Code → Understand Feature → Match Android Codebase Patterns → Implement
              (what)                    (how it's done here)

Preserved: Feature behavior, data structure shapes, business logic, user flows Adapted: Language idioms, frameworks, patterns to match the Android codebase

Workflow

Step 0: Gather Context

Ask the user for both pieces of information:

To port a feature from iOS to Android, I need:

1. PATH TO iOS CODEBASE (source of truth)
   Where is the iOS project located?
   Example: /path/to/ios-app or ../ios-app

2. FEATURE TO IMPLEMENT
   What feature or component should I port?
   Example: "UserProfile screen" or "the authentication flow" or "src/Features/Checkout"

Assumptions:

• Current working directory = Android codebase (target)
• User provides path to iOS codebase (source)

If the user already provided this info, proceed. Otherwise, ask.

Step 1: Locate the iOS Feature

Navigate to the iOS codebase path and find the relevant files:

1. Go to the iOS path provided
2. Find files related to the feature
3. Read and understand the implementation

Step 2: Analyze the iOS Code

Thoroughly understand:

| Aspect | What to Extract | |--------|-----------------| | Feature Behavior | What does this feature do? User-facing functionality | | Data Structures | Models, types, enums - their shapes and relationships | | Business Logic | Core logic, validations, transformations | | State Management | What state exists, how it flows | | API Contracts | Network calls, request/response shapes | | UI Flow | Screens, navigation, user interactions | | Edge Cases | Error handling, loading states, empty states |

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                    iOS FEATURE ANALYSIS
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## Feature: [Name]

### What It Does
[User-facing description]

### Data Structures
[Key models and their relationships]

### Business Logic
[Core logic summary]

### State
[What state is managed, how it changes]

### API Calls
[Endpoints, request/response shapes]

### UI Flow
[Screens, navigation]

### Edge Cases Handled
- [Case 1]
- [Case 2]

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Step 3: Analyze Android Codebase Patterns

Before implementing, understand how THIS Android codebase does things:

1. Check if .claude/codebase-style.md exists - If yes, use it and skip manual analysis
2. Find similar features in the codebase
3. Note the patterns used:

• Architecture pattern
• UI framework and patterns
• State management approach
• Networking approach
• Dependency injection
• File/folder organization
• Naming conventions

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               ANDROID CODEBASE PATTERNS
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Style Guide: [Found / Not found]

Patterns observed from existing code:
- Architecture: [what pattern is used]
- UI: [how UI is built]
- State: [how state is managed]
- Networking: [how API calls are made]
- DI: [how dependencies are injected]
- Navigation: [how navigation works]

Similar features to reference:
- [Feature 1]: [path]
- [Feature 2]: [path]

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Step 4: Create Implementation Plan

Map the iOS feature to Android equivalents using the patterns from Step 3:

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                  IMPLEMENTATION PLAN
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## Files to Create

| # | File | Purpose | iOS Equivalent |
|---|------|---------|----------------|
| 1 | [path matching codebase conventions] | [purpose] | [iOS file] |
| 2 | ... | ... | ... |

## Key Mappings

| iOS Concept | Android Equivalent (matching codebase patterns) |
|-------------|------------------------------------------------|
| [iOS thing] | [Android equivalent as done in this codebase] |
| ... | ... |

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Step 5: Implement

Create the Android implementation:

• Match the codebase's existing patterns exactly
• Use the same architecture, UI patterns, state management as other features
• Follow the same naming conventions
• Keep data structure shapes equivalent for API compatibility

Step 6: Copy Assets (if needed)

If the feature uses assets, offer to copy them:

Assets that may need to be copied:

• Images, icons, colors, fonts, Lottie animations, sounds, etc.

If assets are needed and the user wants them copied, use file operations to transfer them from the iOS codebase to the appropriate Android locations.

Step 7: Report Results

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                 iOS → ANDROID COMPLETE
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## Feature: [Name]

### Files Created

| File | Purpose |
|------|---------|
| [path] | [description] |

### Feature Parity Checklist

- [x] Core functionality matches iOS
- [x] Data structures equivalent
- [x] Error handling preserved
- [x] Loading states preserved
- [x] Edge cases handled
- [x] Matches Android codebase patterns

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Triggers

"ios to android"
"convert from ios"
"port this swift to kotlin"
"implement this ios feature for android"
"android version of this ios code"

Integration with style-guide

Recommended: Run the style-guide skill on the Android codebase first.

style guide     ← Run this first on Android codebase
ios to android  ← Then run this

This generates .claude/codebase-style.md which this skill will automatically reference.

If style guide exists:

• Skip manual pattern analysis (Step 3)
• Reference the documented patterns directly
• Ensure perfect consistency with existing code

If no style guide:

• This skill will analyze patterns manually (Step 3)
• Consider running style-guide first for better results

Tips

1. Don't translate literally - Understand the feature, then implement idiomatically
2. Match the codebase - Use the same patterns as existing Android code
3. Keep data shapes equivalent - API compatibility matters
4. Handle platform differences - Some things work differently (lifecycle, permissions)
5. Verify feature parity - Same behavior, not same code