dominikbucher

AsyncAPI is about specifying push-based APIs (which are still far less standardized imho), and not about if a HTTP endpoint processes requests asynchronously (if that's what you meant). For example, if you let clients connect to your system via WebSocket - how do you specify the format of the push messages sent over the WebSocket channel?

Can't speak for all languages and usecases, but at least in Scala its primary use (afaik) is to enable the compiler to reason about the correctness of an application (i.e., it knows all the possible subclasses of a class and can tell you if you forgot to handle some case). I think this is also useful in other languages if you have some logic somewhere that depends on knowing all possible subclasses of a class (independent of the compiler generating warnings or not).