The ClientTick Event is fired every tick on the client.

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

Event interface extensions

Link to event-interface-extensions

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

There is no additional information besides the information mentioned in the interfaces above.

ZenGetters/ZenSetters/ZenMethods from extensions

Link to zengetterszensetterszenmethods-from-extensions

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