Component architectures promote cross-project code reuse by facilitating composition of large applications using off-the-shelf software components. Existing component architectures are not geared towards building efficient parallel software applications that require tighter runtime integration of largely independent parallel modules. We have developed a component architecture based on Converse, a message-driven multiparadigm runtime system that allows concurrent composition. In this paper, we describe an interface model for this component architecture, which allows reusable component modules to be developed independently of each other, and mediates, monitors, and optimizes interactions between such components.