Manhattan Active Omni solution provides clients the ability to integrate with a 3rd party external promotions engine to apply automatic promotions as well as promotions tied to a coupon code during order capture or order edits. As changes to the order are made, a new promotion call can be triggered and the discounts associated to the applied promotions are saved on the order and used in order total calculations. These discounts can be applied against the order, specific order lines, specific charges, and directly against the item price.
Manhattan Active Omni has pre-built apps with many 3rd party Promotion Engines which can be leveraged out of the box. Please see each 3rd party vendor to view what functionalities are available.