Helium allows for running user defined scripts. 

Scripts are small code blocks that performs various operations on files, artists, albums etc.

You can automate tasks such as tagging, file renaming, bpm calculation and more.

Helium is shipped with a few demonstrative scripts that you can take inspiration from, improve or rebuild. 

From more in-depth information about click this link.

Running scripts

To run a script, click Tools > Run script...

This will open a window allowing you to select which script to run. Select a script to see more information about it.

Please note that scripts does necessarily not run on tracks only, sometimes scripts are executed on the entire library or visible albums.

This shall be displayed in the "Script scope" text-label.

After you have selected the script to execute, click OK.