app-version.cs

[Route("version")]
public ActionResult Version()
{
    var version = "DEV Build?";
    var descriptionAttribute = this.GetType().Assembly.GetCustomAttributes<AssemblyDescriptionAttribute>().FirstOrDefault();
    if ((descriptionAttribute?.Description ?? version) != version && descriptionAttribute.Description.Length > 0)
    {
        version = descriptionAttribute.Description;
    }
    return Content(version);
}