What gets cached?
If an AMP page is valid and is requested (so the Google AMP Cache is aware of it), it will get cached. Any resources in AMP pages, including AMP images, also get cached.
Can I stop content from being cached?
No. By using the AMP format, content producers are making the content in AMP files available to be cached by third parties. For example, Google products use the Google AMP Cache to serve AMP content as fast as possible.
Can the cache be crawled?
No. The Google AMP Cache is roboted to crawlers. We recommend that search engines process cache links according to the guidelines for crawling Google AMP Cache URLs. For more information, see robots.txt.
Are there size limits on resources?
Yes, the Google AMP Cache does not fetch any resources (i.e., HTML, images, fonts) that are larger than 12 MB. In these cases, the Google AMP Cache returns a 404 error.
How can I identify crawl requests by the Google AMP Cache?
You can use reverse DNS lookup to identify requests initiated by the AMP cache as described in the verifying GoogleBot guide.