command | curl -F "content=@-" https://clipboards.drifting-through.space
You can add anything after the returned URL, as long as the first character is not a number. A few extensions will actually get the right Content-Type sent along :)
Files with Content-Type support are:
application/pdf pdf image/jpeg jpg jpeg image/gif gif image/png png text/html html text/x-csrc c video/mp4 mp4 audio/mpeg mp3