I used python before, and I converted one of the http servers that I had into async/await app, I used async libraries like aiopg or aiohttp. But say I have jdbi/jdbc based app, how do I convert it into async using coroutines without an async library or spawning any additional threads?

you cannot convert blocking call to async without explicit or implicit threads; simple option is smth like

fun asyncCall() = async(IO) { blockingCall() }

I just wonder how it’s done in python, I don’t think it spawns any threads

aiohttp is built as async from scratch, you can check kotlinx-io or ktor as sample of similar approach implementation in kotlin

aiopg though is just an async wrapper around blocking psycopg library, so I was looking for an example of how to do similar thing in kotlin