Krossbow
See the project's website for documentation.
Krossbow is a Kotlin multiplatform STOMP 1.2 client with a coroutine-based API. It provides a bunch of adapters for popular web socket clients (OkHttp, Ktor, Spring, SockJS...), as well as a 0-dependency built-in web socket implementation for some platforms.
License
This project is published under the MIT license.