@Serializable
data class Reader(
        var name : String = "",
        var photoUrl : String = "",
        var address : Address = Address())

Kotlinx Serialization setup

Do you have kotlinx-serialization gradle plugin applied?

The message is saying about a class “Reader”. Do you have any class in your code called like that missing a @Serializable annotation?

@rudolf.hladik The docs (https://ktor.io/servers/features/content-negotiation/serialization-converter.html) didn't mention about applying a plugin. Thanks a lot!

@manlan it’s only in kotlinx.serialization, https://github.com/Kotlin/kotlinx.serialization

Yes, that's where I saw the guide. But ktor should improve the docs, which is being done anyway 🙂

Actually I think docs are pretty ok, at least in server side, compared with other tools. Maybe it is just the amount of things you can do… xD It is a bit weird that you need to apply a plugin… with Gson it is not needed for serialization…

because Gson uses reflection, kotlinx.serialization don’t