Hmm. The closest thing I have to that is the Book I write myself that outlines the important aspects and rituals of my religion. Entries are revised and changed as needed, but provided they are an accurate reflection of what I currently do, they are something of a "supreme authority." Read the entry I have on energy work and it will tell you my approach towards that subject, for example. The Book isn't intended to extend to anyone other than myself, though, although the files that make it in there have a fair bit of research and experience behind them.
I've got my own one of these too