There's LBRY. Not sure whether their API is open tho, but I suspect it is.
Discussion
Did a little digging around.
- They claim that LBRY works as a protocol rather than as a service
- They rely on their own shitcoin blockchain and use their own shitcoin as a payment system.
If it could be replicated with bitcoin, while remaining economically viable, then I'd say it's an ideal candidate for nostrification.