The
solidus-sdk was spearheaded by Joel Saupe (
@joel) over at Deseret Book, but I believe that he doesn't work there anymore. I've not actually seen a store use it before (besides presumably Deseret Book), and it doesn't appear to be actively maintained. The folks over at Deseret Book made most of their open source stuff private a while back and our main contacts there have since left the company.
That's not to say that you might not be able to find someone to help you with solidus-sdk around here, just a warning that I don't think a lot of people have used that package.