Navigation Kotlinx Serialization

This optional JVM 11 adapter creates a Core NavRouteSpec<T> from a Kotlinx KSerializer<T>. The source-registered 0.1.0-alpha01 exposes Navigation Core and Serialization Core, has no platform dependencies, and is intended for flat route schemas.

Create a route spec

@Serializable
data class ProfileRoute(
    val userId: Long,
    val tab: String = "posts",
)

val ProfileDestination: NavRouteSpec<ProfileRoute> =
    serializableNavRouteSpec(name = "profile")

fun serializableRouteSample(): ProfileRoute {
    val route = ProfileDestination.encode(ProfileRoute(userId = 42L))
    return ProfileDestination.decode(route)
}

The reified overload obtains the serializer; other callers pass it. Exact mapping is Boolean to BooleanValue, Byte/Short/Int to IntValue, Long to LongValue, Float/Double to their matching value, Char/String/enum to Text, and nullable scalars to their value or Null.

The root must be a class or object with scalar, enum, nullable-scalar, or supported inline-scalar fields. Construction rejects nested objects, collections, maps, polymorphic/contextual shapes, unsigned fields, non-object roots, and non-finite floats. Call-local JSON bridges the serializer; only immutable NavRoute/NavValue is retained. Decode rejects unknown names, invalid nulls, and wrong variants; omitted defaults are reconstructed. Keep schema restore-compatible; alternative JSON names are disabled.

See Navigation Core, architecture, Compose migration, and the generated API.