We designed Nold in a way that you have an option to use it offline. You need internet connection (wifi or cellular) to activate the device, but once its activated, you don't need internet to operate Nold.
You also need internet to share access with your guests. This can be done remotely on your phone or even in your browser with Nold Cloud. Your guest also needs to be online to accept the invitation and to download the key, but after that, it will work offline.
If you want to revoke access from a guest, you also need an active internet connection to activate the changes on your device.