Last I investigated, the ergonomics of the websockets API in OpenResty didn't really seem like a good candidate for building websocket based applications. As an example, there's no trivial way to keep track of all connected clients and broadcast a message to them without overly complicated solutions. It's not trivial to listen to events from different asynchronous sources at the same time. (probably other things too but I don't remember right now) OpenResty/Nginx is not a general purpose event loop. The fact that it's primarily an HTTP webserver is evident in the design of the interfaces that are made available.
That said, there's nothing stopping you from and utilizing the `ngx` APIs directly, there are just a few considerations to be made with database connection pooling, but generally you can `require` any Lapis module and use it anywhere in Lua code. For websockets in OpenResty look here: https://github.com/openresty/lua-resty-websocket
The reason the issue is still open is not because I'm not interested in adding it, but because I didn't feel Lapis could provide a useful abstraction at this time.