The Httpful package is fantastic. Searching around I couldn’t find out how to use Httpful\Request::post to send post data to a endpoint. Here’s what I figured out:
<?php
$response = Httpful\Request::post($url)
->body(['foo' => 'bar'], Httpful\Mime::FORM)
->send();
One the receiving end, you’ll be able to access your info from $_POST. If you found this, you were probably fruitlessly searching the web for the answer just like me. I hope this helps.