What API would you choose to represent your network?

So,

 

I've arrived to a point where I got tired of the massive amount of different vendors the company I work in is using and decided it's time to automate everything I could possible think of.

 

Great idea, right? Problem is all these different vendors use different CLI syntax or only posses a GUI interface so creating an automation for each one would take a life time.

 

Which lead me to the grand solution of setting up a 'proxy machine' which would accept a universal syntax on one end, and GET/POST this as commands to the infinera/cisco/juniper/ciena/extreme/microsens/nextone/alcatel and whatever other crap I've got here. Basically it takes some API commands on input, then turn it into syntax which the device recognize in its shell/gui. End game is to keep the automation apps in check whenever they need to read/write something on the network.

 

Thing that keeps me at night is what API to choose for the front end of my server. Should it be REST? Should I have something customized. Feel free to destroy my idea at will.