Is there still no Gradle plugin to generate Kotlin code based on (any platform) Kotlin code (similar to java annotation processors), or any kind of plans/KEEP for metaprogramming in Kotlin ? Something like official compiler API to manipulate (or even read only) the AST would be really nice.

There's kapt for annotation processing. And you can implement your own code generators, e.g. by using kotlin poet

Annotation processing works only for Kotlin JVM, I want something similar for any platform 🙂

Oh, I see, I've misunderstood the question. I don't think there is anything like that, at least I haven't seen or heard anything about it, but I haven't purposefully researched the topic.

Yes, they're planning a an official compiler plugin API. There are hints about it scattered trough a lot of videos and forums, eg. here's a sentence about it:

Yeah I have noticed a few things inside the repository regarding IR but I'm being impatient for an official (beta/experimental) release.. 🙂

You can make a gradle plugin that uses KotlinPoet, like SqlDelight is doing.

Generating code is not the problem, reading (and maybe modifying) the AST in a proper way is 🙂