Abstract: Disclosed is a smart device housing configured to fixably attach to a beverage vessel having a domed surface at a distal end, the domed surface adjacent a wall terminating at a lip, the smart device housing including an exterior configured as a transformable shape enabling a locking fit between the lip and the domed surface of the beverage vessel. Also disclosed is a system wherein a smart device has at least one proximity, image or distance sensor having a beam of detection with a path, the sensor located and directed such the beam of detection covers a location where a coupler can be attached to the beverage vessel, the smart device configured to determine whether the coupler is attached to the beverage vessel by measuring whether the path is obstructed by the coupler. Also disclosed is a method of determining the fill status of a beverage container.