Most of my clients produce and save a Postman file that I can use to test and mimic their REST API. I would find a Postman file to most helpful. And it would be useful for Particle to do nightly testing of your APIs.
The API should be fully documented. As is the beauty of open-source: Please do make such a file and share it with the community, I'm sure we could all benefit if they're as useful as you say they are!