Q:

REST calls across site collections?

Having trouble finding a clear answer on this but can I do REST calls to a library across Site Collections within the same domain?
So if I have mysite.com/r/Site1 and mysite.com/r/Site2
Given permissions on Site 1 are set to everyone in the AD can read.
Will I be able from Site 2 to return documents from a list in Site 1 using the REST API?
I know I can use the Search API but I'm curious about REST

A:

If the both Site Collections are under the same hostname (for example https://my.site.com for both of them), and if the user has the correct permissions, then yes you can use REST.

