Steps

•

Read gradle/libs.versions.toml and add the navigation dependencies:

Under [versions]:

code

navigation3-ui = "1.0.0-alpha05"
lifecycle-viewmodel-navigation3 = "2.10.0-alpha05"

Under [libraries]:

code

navigation3-ui = { module = "org.jetbrains.androidx.navigation3:navigation3-ui", version.ref = "navigation3-ui" }
lifecycle-viewmodel-navigation3 = { module = "org.jetbrains.androidx.lifecycle:lifecycle-viewmodel-navigation3", version.ref = "lifecycle-viewmodel-navigation3" }

Important: Before adding, search the web for the latest stable version of these libraries. Use latest stable — no alpha/beta unless no stable exists yet (Navigation 3 is currently alpha-only, so alpha is acceptable here).

•
Read composeApp/build.gradle.kts and add to commonMain.dependencies:
kotlin
```
implementation(libs.navigation3.ui)
implementation(libs.lifecycle.viewmodel.navigation3)
```
Also ensure kotlinx-serialization plugin is applied (needed for type-safe routes):
- •Add serialization plugin in [plugins] of version catalog if missing
- •Apply it in composeApp/build.gradle.kts
- •Add kotlinx-serialization-core to commonMain dependencies
•
Create the navigation setup at composeApp/src/commonMain/kotlin/io/ak1/docubox/navigation/:

NavRoutes.kt — Define routes as serializable data objects/classes:
kotlin
```
@Serializable
data object HomeRoute : NavKey

@Serializable
data class DetailRoute(val id: String) : NavKey
```
NavConfig.kt — SavedStateConfiguration with polymorphic serialization (required for iOS/non-JVM):
kotlin
```
val navConfig = SavedStateConfiguration {
    serializersModule = SerializersModule {
        polymorphic(NavKey::class) {
            subclass(HomeRoute::class)
            subclass(DetailRoute::class)
        }
    }
}
```
AppNavigation.kt — Main navigation composable using rememberNavBackStack and NavDisplay
•
Update App.kt to use the new navigation composable as root.

•

Verify the build compiles on both platforms:

code

./gradlew :composeApp:assembleDebug
./gradlew :composeApp:iosSimulatorArm64MainKotlinNativeCompile

Key rules

•All route classes must implement NavKey and be @Serializable
•Register every route in the SavedStateConfiguration polymorphic block (required for iOS)
•Use rememberNavBackStack for back stack management — manipulate it directly to navigate
•Do not use the old navigation-compose (org.jetbrains.androidx.navigation:navigation-compose) — Navigation 3 is the current approach for Compose Multiplatform 1.10.0+