Pastel is an open-source, self-organizer task list CLI program I'm planning and making myself, and for myself use. All features and use cases are made based on my personal use and needs.
I really encourage you not using this app, instead learn the code and make your own.
$ todo add "Some task for today next fiting hour" ...
$ todo done 3 ... # Mark 3rd todo as done
For todos management the index of it in the today's list is used.
It seems help the interface's development since no technical info need to be available (i.e. UUID).