David Denton made a Kotlin implementation as part of the larger http4k “Server as a Function” technology that he created for the JDK community. As well as that, two ClimateAPI demos - one that uses Kotlin with the new library, and one that uses plain Java with the same Kotlin library.
David’s intention is to use and support this library going forward.
Library as part of the http4k monorepo: github.com/http4k/http4k/tree/master/http4k-testing-servirtium
Climate API Demo: github.com/http4k/servirtium-demo-kotlin-climate-tck