In normal ASP.NET Web forms sites I would use web.configs \"appsettings\" to add application setting data to a site. However, I am not able to retrieve setting values this way w
Are you ever calling set? I'm guessing it never gets called, so the private variable never gets the value from the config.
Try it this way (just retrieve the value in the get, no set needed):
public string ClientSecret
{
get { return System.Configuration.ConfigurationManager.AppSettings["ClientSecret"]; }
}