Comment by dunham

It's not quite the same, but in the past I've written (in python) scrapers that run off of the cache. E.g. it would extract recipes from web pages that I had visited. The script would run through the cache and run an appropriate scraper based on the url. I think I also looked for json-ld and microdata.

The down sides were that it only works with cached data, and I had to tweak it a couple of times because they changed the format of the cache keys.