A conduit connector assembly is provided for a respiratory therapy apparatus and configured to connect a patient interface to a gas delivery conduit. The assembly comprises: a conduit comprising a first flow port configured to be connected to the patient interface, and a second flow port configured to be connected to the gas delivery conduit, and a supplementary flow port; and a first valve port configured to be closed or opened by a valve flap. The conduit and the valve flap selectively provide an inspiratory flow path from the second flow port of the conduit to the first flow port of the conduit; and an expiratory flow path from the first flow port of the conduit to the supplementary flow port via the first valve port. A supplementary gas flow path is provided between the first and/or second flow ports and the supplementary flow port via a supplementary valve port.