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Sealed classes now do not have any special support, so you should use the same approach as if you were using regular polymorphic serialization (`@Polymorphic` annotation, SerializersModule, etc). We have plans to improve it in future.

Try running my snippet, its that it explicitly doesn't work, while the same structure with an abstract class works

`@Polymorphic` annotation is applied automatically for abstract classes, but not for sealed ones

Can you provide an example on how to fix this?

```
@Serializable
@Polymorphic
sealed class BaseSealed {

  @Serializable
  @Polymorphic
  data class Child(val a: String) : BaseSealed()
}
```

Doesn't work either

Sorry for misleading you, `@Polymorphic` should be applied on a _use-site_ for sealed class: <https://github.com/kotlin/kotlinx.serialization/blob/45aa7c7ab97f25f205408b46a7069886408bce6b/runtime/commonTest/src/kotlinx/serialization/features/SealedPolymorphismTest.kt#L26>
Because special support for sealed classes would be introduced in compiler plugin, we  do not apply polymorphic for sealed classes globally

If you have your sealed class on top-level (unwrapped), you can use `PolymorphicSerializer(BaseSealed::class)` as its serializer to enable polymorphism

nope, polymorphic serialization designed as cross-platform and therefore is reflectionless. That's why ypu have to specify all sublcasses in some module

Can you then please add an annotation for that? Like @Polymorphic(children= [X::class, Y::class])
I really like how I don't have to pass instances around especially in a modularized application