Each controller has its own API, as they use different software.There is no chance to write one for all of them.
However, if you are looking forward to use Z-Way controller, there is API documentation, can be found on http://developer.z-wave.me/?uri=help
But there is no need for that, there is Alexa skill already. Which work pretty well.
Is the Z-Wave protocol dying?
Re: Is the Z-Wave protocol dying?
There is plenty of open source libraries for z-wave. Not for z-wave controllers because they are all they specific APIs. The libraries to build your own controller / talk to z-wave are alive and well.
Wifi is making a lot of progress mostly due to how ubiquitous and easy to set up they are. They are however a dead end if you are looking for serious home automation/control. Wifi is limited to "toyish" implementation with a few devices here and there due to power consumption, cloud dependance, reliability, performance and security.
Wifi is making a lot of progress mostly due to how ubiquitous and easy to set up they are. They are however a dead end if you are looking for serious home automation/control. Wifi is limited to "toyish" implementation with a few devices here and there due to power consumption, cloud dependance, reliability, performance and security.