I would not assume everyone has sqlite but this can be done optionally with a plugin. Will consider writing a demo for this.
Using XDG directories and system secrets sounds a lot better than what I did. I will learn how to use them and try to integrate them with my code!
Used to be everyone used BerkleyDB or some similar key-value store - for a great many usecases SQLite is just pragmatically better.
And it's arguably less exotic than perl.
You should of course do what want - but "just use SQLite" is pretty solid advice when dealing with structured data - and almost certainly better than "smart" text file.
I was more thinking from gp comment that the project might store context or history in its own files - and then SQLite might be a good fit.
Linking to the rust implementation because it’s the fastest and most easily portable: https://github.com/neosmart/securestore-rs