We also made a couple of implementations towards OpenAPI, so collecting such approaches in e.g. the file storage seems like a good idea.
Concerning fully automated approaches (e.g. based on the object-model of OpenACS or the public API), one is exporting more details than desired. The mongoDB interface has the notion of embedding vs. linking complex structures, is designed for different renderers etc. So, there are quite a few ingredients out there.
