Hi. It's a good question.

For now, I just want to build a Roam for myself to save $15/month.

The main different with Roam is I want my app saves data on local, instead of on the cloud.

Obsidian is a good alternative for this, but Obsidian is not block-based, I can't achieve something like block level reference. It's an important feature for me.

The link I post here is not a note app, it is an editor libaray. I use this library to build my note app. I think I can open source the editor core so that the other one can build their own block-based note app.