Is there a way to tap into the iCloud photo library/stream with third party tools. I'd like to do that for an independent backup. The Amazon Prime photo app man

Is there a way to tap into the iCloud photo library/stream with third party tools. I'd like to do that for an independent backup. The Amazon Prime photo app managed to do it, but I'd like something I can replicate photos to my own home server and not necessarily involve yet another cloud service.