docs/reference/koin-core/start-koin.md
Quick reference for starting Koin. For detailed guide see Core - Starting Koin.
| Method | Use Case |
|---|---|
startKoin { } | Standard apps - registers in GlobalContext |
koinApplication { } | Testing, SDKs - isolated instance |
koinConfiguration { } | Configuration for Compose, Ktor |
startKoin<T>() | Typed startup with Compiler Plugin |
startKoin {
modules(appModule)
}
startKoin {
logger(Level.INFO)
environmentProperties()
fileProperties()
properties(mapOf("env" to "production"))
modules(coreModule, networkModule)
lazyModules(analyticsModule)
createEagerInstances()
allowOverride(false)
}
| Option | Description |
|---|---|
logger() | Set logging level and implementation |
modules() | Load modules immediately |
lazyModules() | Load modules in background |
properties() | Load properties from map |
fileProperties() | Load from koin.properties file |
environmentProperties() | Load from system/environment |
createEagerInstances() | Create all createdAtStart singletons |
allowOverride() | Enable/disable definition overriding |
Requires Koin Compiler Plugin and @KoinApplication:
@KoinApplication
class MyApp
// Start
startKoin<MyApp>()
// With configuration
startKoin<MyApp> {
printLogger()
}
// Load after startup
loadKoinModules(featureModule)
// Unload
unloadKoinModules(featureModule)
stopKoin() // Global instance
// Isolated instance
koinApp.close()
| Logger | Platform | Description |
|---|---|---|
EmptyLogger | All | No logging (default) |
PrintLogger | All | Console output |
AndroidLogger | Android | Logcat |
SLF4JLogger | JVM | SLF4J |
startKoin {
logger(Level.DEBUG) // or androidLogger() for Android
}
startKoin {
environmentProperties()
fileProperties() // koin.properties
properties(mapOf("key" to "value"))
}
// In module
single {
ApiClient(url = getProperty("server_url"))
}
class MainApplication : Application() {
override fun onCreate() {
super.onCreate()
startKoin {
androidLogger()
androidContext(this@MainApplication)
modules(appModule)
}
}
}
@Composable
fun App() {
KoinApplication(
configuration = koinConfiguration { modules(appModule) }
) {
MainScreen()
}
}
fun Application.module() {
install(Koin) {
slf4jLogger()
modules(appModule)
}
}