I know Bitgo has it. They boast about their API a lot on their website. Then there is Keepkey but I am not sure if it actually has any API ..
OP is looking for something that he preferably can host locally. BitGo might provide the services he's looking for, but they're meant for enterprises and they also have criteria you need to meet before being able to use them. As for KeepKey, I'm pretty sure they don't have such a thing unless you're referring to ShapeShift API.