Prerequisites
In finance and operations apps, a business action that a user performs can be either a workflow action or a non-workflow action. Approval of a purchase requisition is an example of a workflow action, whereas confirmation of a purchase order is an example of a non-workflow action. Both types of actions can generate business events that external systems can use in integration and notification scenarios.
Class extensions are used to implement new business events that allow external systems to receive notifications from finance and operations apps.
To find existing business events in the instance you’re using, go to System administration > Setup > Business events > Business event catalog.