InitializationEvent

Learn more about InitializationEvent

InitializationEvent is an event that is fired when the client launches and mods are loading.

If you are using OneConfig's configuration system, its a great place to initialize your config as well:

@Subscribe
public void init(InitializationEvent event) {
    System.out.println("The game is starting!");
    config = new MyConfig();    // initialize your config 
}