Inactivity Scripts is a Paper Plugin that runs Commands/Scripts on four different events, when the server starts, when the server stops, and when the player count changes to 1 or 0.

You can decide if you want to set a breakpoint, that waits for your script to finish, this is recommended for the server stop, because the plugin being disabled at server stop might crash your Command/Script.

The plugin was only tested in 1.21.9 on Windows 11 and 1.21.11 on Debian 12 but should work with all 1.21 versions.