Use a bungee plugin (from proxy server) api in a spigot plugin (normal server)

Hi all !
I'm trying to make my own plugins for my network but i've got some problems. I don't know how to use my own API (wich is located on my proxy server) on all my spigot servers. Is that working like a basic bukkit plugin ? Just import my own API to the plugin i need ?
I have Googled my question but i didn't find anything.
Thanks, Jonathan.