Is it possible to use external dependencies in https://play.kotlinlang.org?

To my understanding, no. This could be a major security issue. However, the playground is open source, and you can host your own version if you need. And within the self-hosted version you are able to supply your own dependencies

Thanks!

The playground website supports a limited set of external dependencies, such as kotlinx.coroutines and junit.

Cool. Is there a list somewhere? (I was looking for jackson deps)

I think the list is this one: https://github.com/JetBrains/kotlin-compiler-server/blob/77b55564bd24e8a12839768415f3ffa81406c897/build.gradle.kts#L104-L116 …