MessageTweaker

Chat event import club.Gumeng.Messagetweaker.Event.ChatEvent;

ChatEvent gets the player message .message or getMessage()

Command event import club.Gumeng.Messagetweaker.Event.SendCommandEvent

SendCommandEvent gets the player command .command or getCommand()

Use example:

import crafttweaker.api.events.CTEventManager; 
import club.gumeng.messagetweaker.event.SendCommandEvent;
CTEventManager.register<SendCommandEvent>((event) => {
    var command = event.command;
    if ("gamemode" in command) {
        event.cancel();
    }
});