Question Creating a GO Keyboard theme?

Hi devs,

I'm trying to find a way to create a theme for GO Keyboard. I saw many third parties doing that (they have some kind of installer system, applaunches, goes to theme selection screen and instructs user to click activate). I know what the graphic resources are (found them in source of 3rd party theme) but I don't seem to find what to do with that resources. Does Go Keyboard / Go Dev have some kind of API or library? Or I just need to paste the resources somewhere? (I know that GO Launcher Ex themes use some package called com.go.theme.template, is there anything like this for the Keyboard and I'm missing it?)

Thanks in advance.