Look into the new Content Provider API for Jupyter

[mwouts]

Could jupytext use the relatively new Content Provider API as described in:

• Content Provisioning
• IContentProvider
• Add Content Provider API jupyterlab/jupyterlab#17092

To me it looks like jupytext could be a perfect use case for this API.

Originally posted by @krassowski in #133

[mwouts]

Hi @krassowski, thank you for the pointers. From what I saw in the links above I was under the impression that this new API is in Typescript, is that correct? Unfortunately both my current skills and Jupytext's current implementation are mostly in Python so far 😅

Quick other question, do you think this could help with syncing multiple views on paired notebooks, cf. #1401 ?