About two months ago I have gotten into CastiaMC's server and I downloaded a lot of files, included some server backups. Into them I found some plugins made by their developer ("Vegan").
This plugin is called "Chat" and is for have a cross server chatbetween spigot servers, it uses mysql.
The plugin is not obfuscated so you can see the code!
Download: https://mega.nz/#!gF0hASya!e1bbDR9cV6Toc...lDGbSx8tSM
Edit: I forget to publish this on the Minecraft category! can someone move the thread?!