An inventory droid was any droid tasked with logging every item and crew member aboard Imperial cargo ship to ensure the safe delivery of said vessel's cargo. AP-5, a blue-plated RA-7 protocol droid, served as the inventory droid of Cargo transport 241, a transport that was stolen from Horizon Base by the rebel astromech Chopper. Imperial cargo ships were required to have an inventory droid to track and monitor all the goods, ensure it was organized and safely arrived to its destination on time. Also, inventory droids were tasked with logging every item and crew member of the transport and in addition were able to view the Imperial data network.