Doesn’t curl do this just as easily?
How complicated are your requests? If I need to test a POST request with a JSON payload longer than a line or two, I'll go and construct my curl command in a text editor anyway, since the shell prompt / readline is not easy to edit. Once you need to start escaping single or double quotes or html payloads in the request, it quickly gets cumbersome. At that point I ditch the shell as a middleman and use the editor to submit the request for me.