All User Inboxes must, at a minimum, perform certain fundamental operations. These include:
Log in to the Process Engine and instantiate and initialize a VWSession object (creates a Process session).
Query user queues and/or work queues for Queue Elements to display work item information.
Display a list of queues from which the user can select items to work on.
Select a work item from those displayed (as a result of a query) and open the work item, as a Java™ or HTML Step Processor, or Tracker application.
See also Overview of User Inbox Development and Developing a User Inbox.