I have been looking around for this issue and haven't found anything yet.

I want to create a webapp that requests offline access to google api, and the my main concern is that I'm using angular as a front-end and I'm consuming a api created in nancy.

I have been able to get access but only for a couple of hours, but I need the user to grand offline access to the app because it's going to have a task running every amount of time needed.

Have anyone already accomplish this one? Tried? Experience? I've tried to call the google oauth api to request the token but it returns 405 method not allowed.