Another suggestion

[WardLT]

I've been meaning to make a PR for months, but have not found time.

In lieu of depth, I'll go for a quick reply: an API I built in collaboration with colleagues at NIST (Josh Tallion) and Citrine Informatics (Max Hutchinson) is described here - https://materialsio.readthedocs.io/en/latest/user-guide.html#class-interface

It's very similar to what I see with yadg, with just some differences around handling multiple files and allowing a "context" field for supplying options which affect how the extractor operates.