Hey @raygulick - long time no type! 
You can see a live implementation at updates.codepotent.com which is the domain that serves my plugin update data. A couple others have shared their own implementations via Slack DMs, as well… I’ll let them post their own links, just in case I was getting a sneak-preview not intended for public eyes.
I did create a short tutorial on this in response to a question that was wondering which plugins to use to create a headless installation that could serve specific data. As it turned out, I had just created exactly that just days prior. The Headless theme is essentially an installable version of that post. If you have any specific questions about the theme, design decisions, or implementation, feel free to open a post and I’ll be happy to help.