[vibe.d] How to create authentication system via REST interface?

[NX via Digitalmars-d-learn]

I'm trying to understand how to create some json-rest api that 
would return data (in json format) related to that specific 
logged in user. I see the documentation covers these but I'm 
totally new to vibe.d so can't quite figure out putting these two 
things together and make them work. Some easy to follow sample 
would be incredibly helpful, though any help is appreciated.