To be honest, it was not designed as a Headless CMS at the beginning... But the fact is that we split up the code in two parts :
You could of course use your own frontend based on the backend. Fasty Allow you to write quickly an API to expose your data the way you want to.
We gonna start creating some posts with more real examples for authentication, getting elements and display them on your website. Of course we will use or Openresty / Lua frontend but you could use anything else.