This work presents an open-source software package, HADOKEN (High-level Algorithms to Design, Optimize, and Keep Electrons in Nanowires), for predicting the formation of electron gases in core-shell nanowires with arbitrary geometries/shell layers, doping densities, and external boundary conditions. The code utilizes a self-consistent numerical implementation that solves coupled Schrödinger and Poisson equations to obtain wavefunctions, electron densities, and band-bending diagrams . HADOKEN is written in the MATLAB programming environment to aid in its readability and general accessibility to both users and practitioners. Since open-source Schrödinger-Poisson codes for arbitrary core-shell geometries and boundary conditions are not readily accessible, our publicly available HADOKEN code provides a user-friendly program for researchers by reducing the time commitment of writing these complex algorithms from scratch. To demonstrate its utility, we extensively document and provide several examples of different nanowire configurations that can be handled by the HADOKEN software package.