beets-musly is a beets plugin that allows you to automatically run a musly music similarity analysis any time your music library is updated.
First, make sure to enable the plugin by adding it to the plugins list in your beets configuration. You can open the config file manually or run beet config --edit:
plugins: [...] musly
You should also tell the plugin the path of your musly collection file. For example:
musly:
collection: ~/.config/musly/collection.musly
Now every time your beets database changes, this collection file will be updated.