---
slug: "swiff-ios"
source_type: "skill_md"
source_url: "https://cdn.jsdelivr.net/gh/narenreddy2302/swiff_ios@main/SKILL.md"
repo: "https://github.com/narenreddy2302/swiff_ios"
source_file: "SKILL.md"
branch: "main"
---
---
name: swiff-ios
description: Expert assistant for the Swiff iOS subscription and expense management application. Use when working on Swiff iOS features, architecture, SwiftUI/SwiftData development, widgets, notifications, subscriptions, expenses, group billing, security, accessibility, or performance optimization. Provides comprehensive knowledge of MVVM architecture, service layer patterns, and iOS best practices.
---

# Swiff iOS Development Assistant

## Purpose
Use this skill when working on the Swiff iOS project to ensure consistency with established patterns, architecture, and coding standards. The skill includes expertise in:

- SwiftUI declarative UI development
- SwiftData persistence and migrations
- MVVM architecture with service layer
- WidgetKit home screen widgets
- iOS notifications and background tasks
- Subscription and expense management features
- Group expense splitting and calculations
- Security best practices for financial apps
- Accessibility standards
- Performance optimization

## When to Use This Skill

Invoke this skill when:
- Starting work on any Swiff iOS feature or bug fix
- Understanding the project architecture and structure
- Implementing new views, models, or services
- Working with subscriptions, transactions, or group expenses
- Adding widgets or notifications
- Performing code reviews
- Handling data migrations
- Implementing security or accessibility features
- Optimizing performance
- Writing tests

## Project Context

**Swiff iOS** is a comprehensive subscription and expense management app built with:
- SwiftUI for modern declarative UI
- SwiftData for data persistence (iOS 17+)
- Combine for reactive programming
- WidgetKit for home screen widgets

### Core Features
1. Subscription Management - Track recurring subscriptions with renewal reminders
2. Expense Tracking - Log and categorize transactions
3. Group Expenses - Split bills and track balances
4. Analytics - Spending trends and forecasting
5. Notifications - Renewal reminders and alerts
6. Widgets - Quick access home screen widgets

## Architecture Pattern

The project follows **MVVM + Services** pattern:
- **Models**: DataModels (domain) + SwiftDataModels (persistence)
- **ViewModels**: Service layer (DataManager, PersistenceService, etc.)
- **Views**: SwiftUI views with reusable components

## Key Guidelines

### Code Style
- Use `@MainActor` for services that interact with UI
- Prefer `@Published` properties in services for reactive updates
- Follow Swift naming conventions (PascalCase for types, camelCase for variables)
- Use comprehensive error handling with typed errors

### Architecture
- Keep business logic in Services layer, not in Views
- Use domain models (DataModels) for business logic
- Convert between domain and persistence models explicitly
- Inject DataManager via `@EnvironmentObject`

### Testing
- Write unit tests for business logic and calculations
- Test error conditions and edge cases
- Mock services for isolated testing
- Use SwiftUI previews for UI testing

### Security
- Sanitize all user inputs
- Use biometric authentication for sensitive operations
- Encrypt sensitive data at rest
- Follow OWASP mobile security guidelines

### Performance
- Use lazy loading for lists
- Implement efficient SwiftData queries
- Minimize view updates with proper state management
- Profile and optimize widget updates

## Available Detailed Skills

The project includes specialized skills in `.claude/skills/`:
- `project-context.md` - Project overview and navigation
- `mvvm-architecture.md` - Architecture patterns and guidelines
- `swiftui.md` - SwiftUI best practices
- `swiftdata.md` - Data persistence patterns
- `service-layer.md` - Service implementation guidelines
- `subscription-expense.md` - Business logic for subscriptions/expenses
- `widgets.md` - WidgetKit implementation
- `notifications.md` - Notification handling
- `security.md` - Security best practices
- `accessibility.md` - Accessibility standards
- `performance.md` - Performance optimization
- `testing.md` - Testing strategies
- `error-handling.md` - Error management
- `ui-design.md` - UI/UX guidelines
- `code-review.md` - Code review checklist

## Example Usage

When adding a new feature:
1. Review project-context.md for structure
2. Follow patterns in mvvm-architecture.md
3. Implement using swiftui.md and swiftdata.md guidelines
4. Add tests per testing.md
5. Ensure accessibility.md compliance
6. Review against code-review.md checklist