Upvoting you because you're being downvoted and I skimmed the page and somehow missed it at first too. The answer is:

> The plan is to make curl do websockets similar to telnet/nc. That part of the work has not been started.

Edit: Come on man, whoever downvoted me too. It's easy to miss if you skim. I included the answer in my reply. And I tried to save the poster some karma because I thought they were being downvoted more than they deserved. Some people just can't be happy.

See the section under the header "Command line tool websockets"

Your question is answered on the page