This is basically a duplicate of this question, which was answered for prior versions, but whose answer is no longer applicable in El Capitan.
My question includes programmatically: if there's a programmatic / Cocoa way to access the Photo Stream contents stored (somewhere?) on your computer, then perhaps we can build a filesystem-in-userspace or similar to access them?
Best Answer
So, I've answered this for myself: iCloud Photo Library photos are buried in subfolders of
"~/Pictures/*.photoslibrary/Masters"on El Capitan!Using a
savedSearch, the same approach as was popular under Yosemite and earlier, we can create a Finder folder that lists, chronologically, your Photo Stream. The XML version is here (you may have to modify some paths), or you can download my pre-compiled version instead:Ta-da!