Methods and apparatus for analyzing the interface usage and requirements within software applications. In one embodiment, the interfaces comprise application programming interfaces (APIs) used with Java-based software, and the apparatus comprises a computer program that analyzes file paths (or classpaths) containing one or more files comprising Java bytecode. The names of the classes are extracted and placed into a class dictionary. The different classes listed in the dictionaries are broken down into their individual methods. Each method is then dissembled and analyzed for method or field invocations on other classes found in the dictionary. Methods called are added to a “used class” report. The used class report preferably contains the name of the class, method and the instruction information.