NCrystal release v2.2.0 (December 2020) introduced support for plugins, and the NCrystal release v4.0.0 (February 2025) updated the ergonomics of installing such plugins. The plugin mechanism is mainly intended to provide a mechanism with which one can extend the existing NCrystal features, for instance by introducing new or alternative physics models, or adding support for new file formats. Additionally, plugins can be used as a way to provide extra NCMAT data files, beyond what is available in the NCrystal standard data library.

The wiki page PluginsDevelopment contains information for people who would like to develop new plugins. Normally, plugins are developed in git repositories, from which they can be installed easily via pip install. In any case, each plugin should have a unique name. For debugging purposes, the command nctool --plugins can be used to print a list of enabled plugins, nctool --browse shows available datafiles including those from plugins, and ncrystal-pluginmanager --test <pluginname> can be used for a quick test that the plugin is working as intended.

On CuratedPlugins, we contain a curated list of plugins which are regularly tested to work with the latest NCrystal releases.