The rgbmatrix web interface also provides some handy HTTP calls that can be used to create your own scripts.
GET
Clear rgbmatrix:
curl http://rgbmatrix.local/clear
Display Line of Text:
curl http://rgbmatrix.local/text?line=TextString
Display GIF from SD:
curl http://rgbmatrix.local/localplay?file=MENU
Get Version
curl http://rgbmatrix.local/version
Reboot
curl http://rgbmatrix.local/reboot
POST
Transfer and Display GIF
curl -F 'file=@file.gif' http://rgbmatrix.local/remoteplay