Google's Secret Screenshot API

I hope this isn't too off-topic, but the "weird" encoding is is just URL-safe base64 (see https://docs.python.org/2/library/base64.html#base64.urlsafe...).

This is great. Thanks for sharing.

1) I know that google caches those thumbnails and returns a thumbnail instantly when it does have a cached version, do you know what happens when it does not?

2) have you come across any rate limit?