Imported from isradeleon/agents (skills/kmp-android-architecture/SKILL.md). Install upstream with npx skills add isradeleon/agents --skill kmp-android-architecture. Copyright stays with the author.

Clean Architecture

Based on the clean architecture principles for the separation of concerns, but applied to mobile apps development with Kotlin Multiplatform (specificaly with shared UI between Android & iOS with Compose Multiplatform), or also for Android apps development

Key dependencies for KMP projects

• ViewModels
• Compose multiplatform
• Compose navigation (with safe type args since version 2.8.0 or higher) Documentation
• Koin for dependency injection
• Ktor for networking (both platforms)
• Kotlin Serialization (for safe compose navigation args & network serialization)
• Room (supports KMP since version 2.7.0 and higher) with SQLite bundled Documentation
• SQLite bundled
• KSP (Kotlin Symbol Processing)

Key dependencies for Android projects

• Compose
• Compose navigation (with safe type args since version 2.8.0 or higher)Documentation
• Hilt for dependency injection
• Retrofit for networking & Moshi or Gson for serialization
• Kotlin Serialization (for safe compose navigation args)
• Room
• KSP (Kotlin Symbol Processing)

Project structure

project/
├── data
│   ├── mappers
│   │   └── CartMapper
│   ├── repositories
│   │   └── cart
│   │       └── CartRepositoryImpl
│   ├── remote
│   │   ├── dtos
│   │   │   └── CartItemsResponseDTO
│   │   └── source
│   │       └── CartRemoteDataSource
│   └── local
│       ├── entities
│       │   └── CartEntity
│       └── daos
│           └── CartDao
├── domain
│   ├── use_cases
│   │   └── cart
│   │       └── AddItemToCartUseCase
│   ├── model
│   │   └── cart
│   │       ├── Cart
│   │       └── CartItem
│   └── repository
│       └── CartRepository
├── ui
│   ├── screens
│   │   └── cart
│   │       ├── CartScreen
│   │       ├── CartViewModel
│   │       └── CartUIState
│   ├── composables // Reusable UI
│   │   └── cart
│   │       └── CartItem
│   └── navigation
│       ├── Routes // sealed class
│       └── components
│           ├── MyTopAppBar
│           └── MyBottomNavbar
├── common
│   ├── network
│   │   └── apis
│   │       └── CartRemoteDataSourceApi
│   ├── utils // Utility classes
│   └── database
│       └── MyDatabase
└── di // Dependency Injection modules

Layers

Domain

Contains the use cases for business logic, models & repository abstractions.

• Use cases: Define one single business logic operation at a time.
• Models: Represent an object part of the business logic in plain kotlin.
• Repositories: Repositories defined as interfaces to better abstract data for the use cases.

Data

Here are the mapper files, repository implementations, remote & also local data source interfaces (if necessary, since the local database usually doesn't need to change as much as an API could).

• Mappers: Here are the functions responsible for converting DTOs to models and vice versa, named after the domain model. Also models to entities and vice versa. IMPORTANT: Never convert DTOs to entitites or entities to DTOs directly.
• Repositories: Here are the repository implementations.
• Remote: Here are the DTO definitions & remote data source interfaces.
• Local: Here are the Room entities and Daos. Local data source abstractions might not be necessary.

UI

Here we have the screens, reusable UI composables and navigation components.

• Screens: Represent a whole section of the app, like HomeScreen, ProfileScreen, etc. These must be next to their corresponding ViewModel class & UI state sealed class.
• Composables: Reusable UI composables.
• Navigation: Route sealed class for compose navigation.

Common

Here we have the network, utils and database package.

• Network: Here we put the necessary abstractions & implementations for networking. Including the remote data source implementations inside an API package.
• Utils: Utility classes and extensions.
• Database: Here we put the room database abstract class. We store the database constructor here as well.

DI (dependency injection)

Dependency injection modules go here.