This comes directly from the Avaya website.
The one-X Agent API (also known as the Event Notification API) enables developers to create custom clients that can register with one-X Agent and poll for event notifications, making it easy to provide custom screen-pops. The API also enables some basic call control operations to be performed by a custom client. The interface is an XML/HTTP based API where clients make HTTP requests to one-X Agent and receive XML/HTTP responses.
Some of the event notifcation operations enabled by the one-X Agent API include:
RegisterClient: registers a custom client with one-X Agent and creates a notification queue. NextNotification: Enables the client to get the next notification from its notification queue. WorkItemAdded: Notifies the client that a work item has been added to its notification queue. VoiceItemAdded: Notifies the client that a voice item has been added to its notification queue. IMInteractionCreated: Notifies the client that an instant message item has been added to its notification queue. Call control operations include:
MakeCall: Enables a client to make an outgoing call, using one-X Agent. AcceptVoiceInteraction: Enables a client to accept an incoming call, using one-X Agent. For information about the full set of supported operations, see the Avaya one-X Agent API guide, available for download under Releases for the release of one-X Agent you are using.