matrixtool client upload - Upload a file to the media repository
$ matrixtool client -u @me:example.com upload avatar.png
This command uploads a file to the media repository of a Matrix homeserver, printing the returned mxc:// URL.
Normally the MIME type must be supplied as a second argument, but in the common case of files whose names end in certain recognised file extensions, the MIME type can be automatically inferred for convenience.
The recognised extensions are
.jpg, .jpeg image/jpeg .png image/png
Paul Evans <email@example.com>