This repository contains codes for grey-box identification of nonlinear dynamical systems using TensorFlow and Keras. The core components are a set of custom Keras layers. The "Physics" layer will need to be defined independently for any particular example. Three example systems are included---a CSTR, a continuous bioreactor, and a continuous bioreactor using prior phenomenalogical information (see companion paper for details). A second file will need to be generated for each system to define the GB-ANN object---examples are provided for each example system.