A system and method for programmatically determining interface information for a graphical program. Interface information for a graphical program may include information necessary to invoke execution of the graphical program. A first program may receive a request for information regarding an interface of a graphical program. In response to the request, the first program may programmatically determine the information regarding the interface of the graphical program. The interface information may include such information as parameters of the graphical program, their respective data types, whether each parameter is an input parameter, an output parameter, or both, and default values for input parameters. The programmatically determined information regarding the interface of the graphical program may then be returned to a second program. The second program may invoke execution of the graphical program according to the received information.