Yep, this was the one! It looks great though I hadn't got around to trying it. Do you think something like Cue makes for a better representation for lowdefy apps than YAML, since it seems to offer better abstraction ability and hence easier to compose?

It's an interesting thought. I'll definitely spend some time to consider how this could work.

Although, writing apps in yaml or json works really well currently. We mostly express logic through Lowdefy operators. We like supporting yaml / json since it is easy to write code to create or update such apps in any language.