I think n8n supports sqlite or postgresql, or do you mean am extra database to do other stuff?

I’ve tried a few of these, and I’ve never found one that doesn’t feel like I’m inviting a sales rep to live on my home server. They’re technically open source, but it’s obvious their primary purpose in this form is to upsell you. I understand it, but it’s just not what I want so I’ve ended up getting rid of each one after tinkering with them for a while.

I guess the same could be said for n8n, but I find it more tolerable. I have set up a Valkey instance though and use it for persistent storage through n8n’s Redis support. That works well enough for my fairly limited use case.

Ok, it wasn't clear because supabase it's not even self-hosted. I checked out baserow and grist and you can connect it to an external postgresql db so it should be valid for your use case. I personally used omnidb but it looks abandoned