I made another thing: https://pinin4fjords.github.io/nf-metro/dev/playground/ nf-metro playground editor. Still possible to make quite a mess, but I've made it so you can start from one of the many in-built examples easily. Please smash the 'report a bug' button at the top right when renders do crazy stuff, it will basically make github issues for you, with the dodgy mmds in-built.

This is really nice to work with. It doesn't seems to like when you put more than one node outside subgraph 😅

graph LR
	a[Input]
    c[Output]
    subgraph only [Only Section]
        b[Process]
        a -->|main| b
        b -->|main| c
    end

There's very much an assumption that nodes stay in subgraphs, the model depends on it. I should make the editor block that

Could files reside outside ? This would be really nice.

Yeah, you put in an early request for that. But it's harder than it sounds. The layout is only possible because I make some simplifying assumptions about how I can lay out sub-graphs individually and then connect them, rather than having to reconcile the relative positions of all the nodes across the page. As soon as you start moving things outside the graphs things get harder. I can think about how to make it visually look like what you want, but something for the future.

Thanks for trying. This would be a nice additional feature but the tool is already really nice. If we can export the result in svg, this could be manually done relatively easily.