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kotlinlang

Hello!

I want to use a third-party API that expects either int or string as a value for id. Like:

```Request {
    id: int | string,
    name: string,
    // other fields
}```
How do I do that with kotlinx.serialization? I only need to serialize my classes to JSON, no deserialization.

Tried setting the id type to `Any` and just store a String or Int in it?

No, because:

1. I want more type-safety
2. Serializer has not been found for type ‘Any’. To use context serializer as fallback, explicitly annotate type or property with @ContextualSerialization

I’m thinking about a sealed class, like `Either` + custom serializer

Ok. Last guess I will bother you with. Does the api actually distinguish between int and string ? Or will it simply accept both… ie. is id=42 equivalent to id=“42”

I don’t know, but I guess yes. String ids are like usernames: `@user`

I would go for a sealed class and a JsonParametricSerializer: <https://github.com/Kotlin/kotlinx.serialization/blob/master/docs/json_transformations.md#json-parametric-polymorphic-deserialization>