The CompassAE Commerce Engine uses the engines that implement Parties, Products and Orders, and adds the ability to conduct commerce. It implements a pricing engine, fees, payment gateways.

The CompassAE Financial Accounting Engine implements the basic classes that allow either interface or implementation of general ledger, accounts payable and accounts receivable modules. This module is experimental at this stage.

The Inventory Engine in CompassAE implements a set of models for storing information about the availability and location of ProductTypes and optionally Product Instances. It is also the root for yield and revenue management requirements to segment and allocate inventory for different purposes.