This package provides two Jupyter notebooks that demonstrate how to model escaping exoplanet atmospheres using Athena++ and perform post-processing with Cloudy: Running_Athena_Simulations.ipynb — A guide to set up Athena++ simulations of exoplanet atmospheric escape, including 2D and 3D test runs. Running_cloudy_with_Athena++_output.ipynb — A step-by-step explanation of how to run the post-processing radiative transfer code using Cloudy, based on the output from Athena++. This post-processing framework, designed to take Athena++ simulation outputs, run Cloudy, and perform radiative transfer calculations based on Cloudy’s results, was originally developed by Keith Baka. It was later improved and adapted for use with various planetary systems by Fabienne Nail. A full scientific description of the framework can be found in: "Probing the extent of WASP-52 b’s atmosphere – High-resolution observations and 3D modeling insights" by Nail et al. (2025). The corresponding post-processing framework is also available on GitHub: https://github.com/FabienneNail/AthenaCloudyRT.git. All necessary software requirements and instructions are included within the notebooks.