android-di-koin

Android / KMP Dependency Injection (Koin)

Principles

• One Koin module per feature layer — create it only if there are dependencies to provide.
• Modules are assembled in :app, never in feature modules themselves.
• In Compose root composables, always inject ViewModels via koinViewModel().

For DSL fundamentals (scopes, qualifiers, parameters, get()/inject()) see the koin-patterns skill; for shared/commonMain wiring see kmp-di.

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Dependencies

Use the BOM so every Koin artifact stays on one version (current stable: 4.2.2):

// :app
implementation(platform("io.insert-koin:koin-bom:4.2.2"))
implementation("io.insert-koin:koin-android")          // startKoin, androidContext, ViewModel DSL
implementation("io.insert-koin:koin-androidx-compose") // koinViewModel/koinInject (pulls koin-compose-viewmodel)
testImplementation("io.insert-koin:koin-test")         // verify() / verifyAll()

// feature modules: platform-free DSL only
implementation(platform("io.insert-koin:koin-bom:4.2.2"))
implementation("io.insert-koin:koin-core")           // :data — module {}, singleOf, factoryOf
implementation("io.insert-koin:koin-core-viewmodel") // :presentation — viewModelOf

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Module Definitions

Prefer the constructor-reference overloads (singleOf, viewModelOf, factoryOf) — they are more concise and let Koin resolve parameters automatically. Only fall back to the lambda overloads (single { ... }, viewModel { ... }, factory { ... }) when constructor injection alone is not enough, e.g. when you need to call a factory method, pass a named/qualified dependency, or do post-construction setup.

Imports (Koin 4.x):

import org.koin.core.module.dsl.singleOf      // also factoryOf, viewModelOf, bind
import org.koin.compose.viewmodel.koinViewModel
import org.koin.compose.koinInject

Stale APIs the IDE still suggests — reject them:

• org.koin.androidx.viewmodel.dsl.viewModelOf / .viewModel are @Deprecated ("Moved ViewModel DSL package") → use org.koin.core.module.dsl.*.
• stateViewModel() / getStateViewModel() were removed in Koin 4.x — they no longer resolve. Use the plain viewModel DSL; SavedStateHandle is autowired into any viewModelOf(::X) definition (Koin builds it from the owner's CreationExtras).