Makes me think of a toy node.js module I wrote a white back, read-or-execute[1]. I was kind of inspired by Ansible inventory. You specify a ANSIBLE_INVENTORY=some-file. If the file is not-executable, it reads that file as the inventory. If the file is executable though, it runs the file and uses the stdout. I thought it was neat that there could be either a static file, or something generating the contents, and made read-or-execute, which follows this heuristic.
I can imagine a small Go program with a builder api that outputs Yaml to accomplish this naml goal. I feel like I don't understand what naml is, what it does, how it operates, from a quick 5 minute cruise around. There's some high level vision & goals, but I feel quite disconnected from the "what is happening" part.
[1] https://github.com/rektide/read-or-execute