Plugin Development

A Quod Libet / Ex Falso Plugin is a simple python module or package which contains sub-classes of special plugin classes. These classes can provide special methods that get used by QL or can take action on certain events.

At the moment the following plugin classes exist:

Plugin Types

Event Plugins
  • Are instantiated as long as they are enabled or QL is running. They get notified when songs start, get added etc.

  • Can also (3.10+) listen to selection changes in the main songlist.

  • Example: scrobbler that watches what you play and sends the information to

Tag Editing Plugins
  • Can extend many parts of the tag editor.

  • Example: Title case your tags.

GStreamer Plugins
  • Can inject elements into the GStreamer pipeline and configure them on the fly.

  • Example: Tempo adjustment to play music/audio books faster.

Play Order: Shuffle Plugins
  • Can decide which song to play next or what happens if you select one.

  • Example: weighted shuffle, which prefers higher rated songs.

Play Order: Repeat Plugins:
  • How to repeat the songs

  • Example: repeat each song a set number of times

Songs Menu Plugins
  • Can be accessed through the play list context menu and get passed all selected songs.

  • Example: Album art search, to search album art for all selected songs.

Playlist Plugins
  • Similar to Songs Menu plugin, and in fact derived on the same base class

  • Can be accessed through the playlist context menu in the Playlist Browser

  • Example: remove duplicate songs from a playlist.

Cover Source Plugins
  • Fetch covers from external or local resources

Location of Plugins

In older versions of Quod Libet, before they were moved into the main quodlibet module, plugins could be placed in ~/.config/quodlibet/plugins on many Linux systems, and in ~/.quodlibet/plugins on MacOS.

Whilst this still may work, we recommend installing from source (see Creating a Development Environment) for all plugin development, which will allow a fuller integration experience (debugging, etc).

Creating a new Plugin

  1. Assuming you are running from source, put it in quodlibet/ext under a directory according to its plugin type (events/ etc).

  2. Write the following into the file:

    from import EventPlugin
    class MyPlugin(EventPlugin):
        PLUGIN_ID = "myplugin"
        PLUGIN_NAME = "My Plugin"
  3. Restart Quod Libet, or click the Refresh button in the plugins window.

  4. In Quod Libet open MusicPlugins and search the list for “My Plugin”


  • The best way to find out what is possible is to read the documentation of the plugin base classes .

  • The easiest way to get started creating a new plugin is to look for existing plugins that do something similar to what you want.