Rafael Weinstein's mutation-summary library, from a few years back, includes functionality to transmit & mirror DOM's:

https://github.com/rafaelw/mutation-summary

Not including JavaScript state, I assume, since that isn't exposed by the extensions API to my knowledge.

If that's true, it's still kind of cool, but I think the title is reaching a bit, depending on whether you consider JavaScript state part of the page state (and there's certainly pages where I think that's true).

Extension content scripts can inject script elements into their pages which then allow them to access the page's JS variables. But even then there wouldn't be any way to access key parts of the state like closures.

People who find this useful may also find a number of other web archiving projects helpful:

- https://github.com/machawk1/warcreate

- https://github.com/webrecorder/pywb

- https://github.com/WorldBrain/Memex

- https://github.com/pirate/ArchiveBox

- https://getpolarized.io/

And lots of others here:

https://github.com/pirate/ArchiveBox/wiki/Web-Archiving-Comm...

I would add SingleFile [1] to the list.

[1] https://github.com/gildas-lormeau/SingleFile