Plugin support
(Suggestion, im not sure how to add the label) Im not experienced with go at all, but I suggest getting a good plugin system from the start. After a little googling I came across this , which might be good.
The Plugin Stuff in go is not really good atm. I tried many ways, and allways ended up with pipes to other processes or rest calls. I suggest you check out io.Pipe() and exec.Command() and start the plugin as exec and pipe input data into the executable and receive answers from the executable in a predefined format.
The best bet would be the go plugin definition by hashicorp, it's also used in famous tools like terraform and packer.