CSS Module Loader Core is a loader-agnostic implementation of CSS Modules, built on PostCSS, that processes CSS files to enable local scoping and dependency management. It takes a CSS source string and path, resolves imports and dependencies using a path fetcher, and returns both the final processed CSS and a mapping of local to scoped class names. This tool is designed for developers building CSS Modules support into build tools or loaders who need a flexible, PostCSS-based core for handling CSS Modules transformations.