I think JupyterLite is using localStorage by default. But there are File System APIs for WASM and some external projects[0], I don't think they're yet integrated.
Thanks, yes I see it now. It stores the notebook, which is a json, as a value in the localStorage object, with the filename as a key. Interesting, yes, not quite easy to configure (though I haven't read through the documentation or code to find this).
> I think JupyterLite is using localStorage by default