The TextAPI Compliant Object Store is the back end service we created to host TextAPI resources that are always 100% TextAPI compliant. In fact, the object store is created right from our data model definitions as they are written in Pydantic and the store uses a FastAPI server to retrieve and output resources. We are able to autocreate missing fields like timestamps.
It uses a MongoDB in the background, as MongoDB provides views what we can use to handle embedded resources. This is important for performance reasons as the client does not have to send 1000+1 requests to retrieve all the data needed to present a digital edition.
A word on input and output models. Some mandatory fields will be set automatically if not provided by the request. Thats why we need to define differences between incomming and outgoing resources.