Some features of the package manager can be configured from the files found under ‘/etc/cpt/’. Even though this doesn’t sound like the premise of "no configuration" files, these files are completely optional to the package manager, and still the majority of configuration is done through environment variables. The files on this directory are for configuration that don’t have a big impact on how the package manager behaves, and are not feasible to be used inside simple environment variables (such as the base package list and package manager hooks).