The Computational Crystallography Toolbox (cctbx)  is an open-source library of reusable software components for crystallographic and cryo-EM structure determination. It offers a comprehensive set of tools for processing, analyzing, and manipulating crystallographic and cryo-EM data, and molecular models. From analyzing data to refining and validating atomic models, the cctbx is designed to support the entire structure determination workflow. The introductory tutorial on the cctbx module is tailored for beginners, providing an overview of the module's structure, and an introduction to some of its key functions. Attendees will learn to handle crystallographic data sets, execute basic data analysis, and implement simple algorithms within the cctbx environment. The tutorial exercises will run in a Colab environment, so no local installation of cctbx is needed.