Local Database File Associated with .dwg File

I am planning on building an AutoCAD extension application that will require custom data be stored outside of the standard .dwg file for AutoCAD drawings. I would like there to be a local file that this custom data is stored in so that the data can be read into AutoCAD or saved from AutoCAD while offline. I have been imagining that each .dwg file would have it’s own separate database file associated with it, but I am also open to the idea of having a single data file locally stored in order to allow for offline reading/writing of my custom data. Does MongoDB support this type of local data storage? There will be a cloud-based database where the data can be read from/written to, but I want there to be a local storage system to allow for offline read/write and also improved speed. I am just a bit confused about this because most resources online seem to address cloud storage and I am having a hard time understanding how to use MongoDB to implement a reliable local storage system.