A method and apparatus for creating run-time reconfigurable cores using a core template package. The core template package provides an object-oriented application programming interface for specifying run-time reconfigurable (RTR) electronic circuit designs in a RTR application program. A run-time parameterizable (RTP) core library includes a plurality of predefined RTP core classes that implement selected functions in an electronic circuit design when invoked from an RTR application program. An RTP core template package includes a plurality of template classes. Each template class has a predefined set of method interfaces and fields. The RTP core template package further includes an RTP core template class that includes methods for building, connecting and traversing a hierarchy of RTP core objects based on the template classes and the predefined RTP core classes.