List of potential origins of host domains through which google bot crawls?

Question

What is the potential list of origins of the host domains through which google bot crawls?

e.g.: Like Google cache uses the following domain to crawl the APIs: http://webcache.googleusercontent.com/

I want to add those google domains into my APIs, so Google bot easily crawls my website. So bot or crawler don't get cross origin error.

Answer 1

According to the official documentation, Googlebot always crawls using either the googlebot.com or google.com domains.

It's worth mentioning that the documentation also recommends using a reverse DNS lookup on the bot's IP to fully verify the bot's authenticity.