Upon using Ctrl+F in the official addon documentation -
http://pastebin.com/ZwqMZqYn
I have not found anything about
direction,
facing, or
heading.
Therefore, I do not think anything is currently in the API that allows you to get any information about where the player is facing. You can ask about it, and (usually) get a quick dev response at the addon api forum on the official RIFT forums.
http://forums.riftgame.com/beta-addon-api-development/
It's relatively impossible to do much of anything without access to the character's facing. If/when the API allows you to check your location/coordinates, then you could potentially do checks to figure out which direction the person is moving in... but if they aren't moving, then it is useless.