Is there an easy way to send custom websocket messages over an already established connection?

I don't know of any such capability for HTTP requests either.

Howcome? Because the devs haven't built in the feature

If you need to though dev tools > memory > take snapshot

Filter the snapshot by searching for "websocket", right click the socket in the results and store as global variable

You can then access the socket in the console using the variable temp1

$ temp1.send('foobar')

This is the way.

Done

[removed]

Voted!