R8 / ProGuard

This page explains how Koin behaves under code shrinking and obfuscation (R8 / ProGuard), what Koin keeps for you, and what you need to keep in your own app.

TL;DR

• Koin's core resolution is R8-safe. get<T>(), inject<T>(), and the *Of builders (singleOf, factoryOf, viewModelOf, …) resolve dependencies at compile time — they use reified types and, on Android/JVM, key the registry by Class.getName(). There is no runtime reflection over your constructors, so you do not need to keep your definitions, ViewModels, or their constructors on Koin's behalf.
• Koin ships consumer-rules.pro in its Android AARs (koin-android, koin-core-viewmodel, koin-compose-viewmodel, koin-androidx-workmanager, koin-androidx-startup), so the rules below are applied automatically — you usually don't add anything.
• You still need to keep classes that something else loads reflectively (see below).

What Koin keeps for you (shipped consumer rules)

The AARs silence R8 warnings about Koin internals:

-dontwarn org.koin.**

koin-androidx-startup additionally keeps its manifest-referenced initializer. None of these keep your application classes — Koin doesn't need them kept.

What you must keep

These come from the platform/libraries, not from Koin's resolution:

• Fragments created by KoinFragmentFactory are instantiated by class name. Keep your Fragment subclasses (they're usually kept already via @Keep, layout references, or AndroidX rules).
• WorkManager ListenableWorker subclasses are kept by androidx.work's own consumer rules.
• Saved state for process death. SavedStateHandle is provided by androidx CreationExtras, not by Koin. The values you put into it must survive R8 like any other saved state — keep your own @Parcelize / Serializable state classes:

# Example — keep your own saved-state payloads
-keep class com.example.** implements android.os.Parcelable { *; }

ViewModels & SavedStateHandle (#2044)

A common belief is that intermittent No definition found for SavedStateHandle crashes are caused by R8 stripping Koin's ViewModel reflection. They are not — viewModelOf(::MyViewModel) is compile-time, so a -keep on your ViewModel won't change Koin's resolution.

SavedStateHandle is only available while the ViewModel is being created (it is built from the CreationExtras passed to the factory). Resolve it directly in the ViewModel constructor — do not resolve it lazily or after construction:

// ✅ resolved during creation
class MyViewModel(val handle: SavedStateHandle) : ViewModel()

// ❌ resolved later — the CreationExtras are gone by then
class MyViewModel(koin: Koin) : ViewModel() {
    val handle by lazy { koin.get<SavedStateHandle>() } // fails
}

If you declare ViewModels inside viewModelScope { }, enable the matching option so the scope can be created:

startKoin {
    options(viewModelScopeFactory())
    modules(appModule)
}

Non-Android targets (JS / WASM / Native)

On Android/JVM Koin keys the registry by Class.getName(), which is stable under R8. On Kotlin/JS, WASM, and Native, Koin uses qualifiedName / simpleName from Kotlin reflection. Aggressive name minification on those targets can affect type identity — prefer named qualifiers (named("...")) over relying on class names when you minify non-Android targets.