The ServerTick Event is fired every tick on the server.

You will need to cast the event in the function header as this class:
crafttweaker.event.ServerTickEvent
You can, of course, also import the class before and use that name then.

WorldTick Events implement the following interfaces and are able to call all of their methods/getters/setters as well:

• ITickEvent

The following information can be retrieved from the event:

ZenGetter	ZenSetter	Type
ZenGetter phase	ZenSetter ​	Type string with value of STARTor END
ZenGetter side	ZenSetter ​	Type string with value of CLIENTor SERVER