The ADK includes both a synchronous and an asynchronous processing model. An asynchronous listener notification publishes a document to a webMethods Broker queue, using the doNotify method. Adapter users may process the document's data any way they want to. For example, they can create an Integration Server trigger that receives the document and executes an Integration Server flow service or a Java service.

A synchronous listener notification invokes a specified IS service, and potentially receives a reply from the service and delivers the results back to the adapter resource. In this case, the notification object's runNotification method calls invokeService (instead of doNotify), to process the data produced by the notification. A synchronous listener notification does not publish a document.

Synchronous listener notifications do not support session handling. When a synchronous listener notification calls a service that needs information contained in the session data, that service can fail. However, note that the same service may appear to work for an asynchronous listener notification. This is because asynchronous listener notifications themselves do not execute a service. Instead, an Integration Server trigger, which supports session handling, is used to receive the document and execute an Integration Server flow service or a Java service.