Project Setup — KMP

This guide walks through the minimal project structure for a Kotlin Multiplatform project using Arkitekt with Decompose for component-based architecture and Koin for dependency injection.

Project Structure

shared/
└── src/commonMain/kotlin/com/example/myapp
    ├── navigation
    │   └── HomeNavigation.kt
    └── ui/home
        ├── HomeComponent.kt
        └── HomeState.kt

androidApp/
└── src/main/kotlin/com/example/myapp
    └── ui/home
        └── HomeScreen.kt

State

State is a simple data class defined in common code. It represents the UI state for a given component.

data class HomeState(val title: String = "")

Navigation actions are defined as an interface extending NavigationActions. The parent component provides the implementation.

interface HomeNavigation : NavigationActions {
    fun toDetail()
}

Component

The component extends BaseComponent and is annotated with @GenerateFactory to enable automatic factory generation via KSP.

@GenerateFactory
class HomeComponent(
    @InjectedParam componentContext: AppComponentContext,
    @InjectedParam navigation: HomeNavigation,
    private val someUseCase: SomeUseCase,
) : BaseComponent<HomeState, HomeUiEvent>(componentContext, HomeState()) {

    val state: StateFlow<HomeState> = componentState

    fun onDetailClicked() {
        navigation.toDetail()
    }
}

The @GenerateFactory annotation triggers KSP to generate a HomeComponentFactory class. This factory resolves Koin dependencies (such as someUseCase) automatically — you only need to supply @InjectedParam arguments manually when creating the component.

For full KSP setup details and advanced configuration, see the Factory Generator page.

Screen Composable (Android)

On the Android target, the screen composable receives the component directly and collects its state as a Compose state.

@Composable
fun HomeScreen(component: HomeComponent) {
    val state by component.state.collectAsState()
    Text(text = state.title)

    EventsEffect(component.events) {
        onEvent<HomeUiEvent.ShowToast> { /* handle */ }
    }
}