How to allow sensitive data to be displayed on screen but not saved to file?

[manics]

I found a related idea in:

Exit/abort Save from pre_save_hook?

Currently, all errors in pre_save_hooks are caught and logged, so they cannot cancel the save in progress. This patch will allow you to raise HTTPErrors to cancel saves with a message that will be shown to the user. Until you can require that, though, you need to implement the quota enforcement by overriding ContentsManager.save instead of a hook: from tornado.web import HTTPError from jupyter_server.services.contents.largefilemanager import LargeFileManager class QuotaFileManager(LargeFileMa…

You could try overriding the ContentsManager which handles saving/loading notebooks:
https://jupyter-server.readthedocs.io/en/latest/developers/contents.html#writing-a-custom-contentsmanager