I will abandon this project and focus my contributions to Mopdify-Mopify project, which seems to accomplish what I want.
https://github.com/drsounds/mopidy-mopify
#Bungalow
Open Source Spotify client (designed to be the Eclipse of streaming music clients, other service should be easily integrated).
It should be run in nw.js and is based on a back and front end. The interaction with streaming music client is done in the back-end while the user interface and features (a.k.a Apps) are in the front end.
Last development sprint I used node-spotify but as Spotify announce End-of-Life for LibSpotify, I decided to migrate to Web API. Spotify's Web API is still not supporting streaming at this point, so right now I'm stuck with no streaming possibility. However, I have refactored the code so streaming music API implementation is in a node server back end while user interface are a front end communicating with the back end through a REST API. On this way the code is easier to maintain.
Spotify killed their app finder earlier this year claiming majority are using mobile phones. However many users liked the Spotify Apps and I believe the termination of it's apps program was a financial action more than a shift to mobile. In this project, I have written a framework that emulates parts of the Spotify Apps framework, to encourage people to write plugins for Bungalow. The views are all written in this format.