A Communicator application uses the Microsoft® Office Communicator Automation API to access a Communicator instance and the behind-scenes communications service to manipulate Communicator programmatically, customize the Communicator’s user experiences, or extend its functionality.
The following diagram illustrates the architecture of an Office Communicator Automation API application.
An application first calls Office Communicator Automation API to access a running Communicator instance connected to a Communications Server within an enterprise network. The instance is accessed with the IMessenger interface, the IMessenger2 interface, or the IMessenger3 interface. These interfaces are designated as IMessenger* in the illustration above.
The IMessengerPrivate interface allows an application to work the communications service behind the scenes. An application can use this feature to add contacts and enable Alert Events without going through Communicator UI elements.