Is it possible to pass variables in a websocket $connect call?

I have some existing code using Tomcat and Grizzly webservers, and they accept a path like the following:

wss://<server>/forum/{subject}

It doesn't seem possible to configure API Gateway v2 endpoints to have variables such as subject here. Is that correct or am I missing something?

I realize that I can work around this by sending messages, but it creates an inconsistency from the client perspective and there doesn't seem a good "reason" for it, except it hasn't been done yet.