Interface Minibar / Vending systems.
The wInner Minibar Interface handles the automation with the Automated minibar system. Posting the minibar charges to the guest account is the basic functionality typically offered by such interface. Depending on the Minibar system, additional functionality is possible like Check-in & Check-out messages sent by wInner triggering the minibar system to lock or unlock the minibar in the guest room.
A similar interface exists with Vending systems where the guest can use the roomkey to buy products from the vending system and have these posted to the room account.