We release the MetaboX library, an open source PHP framework for developing metabolic networks from a set of compounds. This library provides easy access to the Kyoto Encyclopedia for Genes and Genomes (KEGG) database using its RESTful Application Programming Interfaces (APIs), and methods to enhance manipulation of the information returned from KEGG webservice. MetaboX includes methods to extract information about a resource of interest (e.g. metabolite, reaction and enzyme) for further processing and storing purposes. MetaboX is modular, thus developers can contribute with alternative implementations or extensions. Each component of the library is designed with minimum dependency on other components. MetaboX follows the SOLID object-oriented design principle in order to provide dependency management, re-usability and flexibility.