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Listening to Events

In this tutorial you will learn to:

  1. Understand Events and Callbacks
  2. Register a callback for an existing Event


Events are represented by instances of net.fabricmc.fabric.api.event.Event which store and call callbacks. Often there is a single event instance for a callback, which is stored in a static field EVENT of the callback interface, but there are other patterns. For example ClientTickEvents groups several related events together.


Each event has a corresponding callback interface, conventionally named EventNameCallback. Callbacks are registered by calling register() on an event instance with an instance of the callback interface as the argument.

Callback Interfaces in Fabric API

All event callback interfaces provided by Fabric API can be found in the net.fabricmc.fabric.api.event package. A partial list of existing callbacks is provided at the bottom of this tutorial.

Custom Callbacks

Although there are plenty of events already provided by Fabric API, you can still make your own events. Please refer to events.


This example registers an AttackBlockCallback to damage players when they hit blocks that don't drop when hand-mined. It returns ActionResult.PASS as other callbacks should still be called. See the AttackBlockCallback JavaDoc in your IDE for the meaning of other values.

  1. public class ExampleMod implements ModInitializer {
  2. [...]
  4. @Override
  5. public void onInitialize() {
  6. AttackBlockCallback.EVENT.register((player, world, hand, pos, direction) -> {
  7. BlockState state = world.getBlockState(pos);
  8. /* Manual spectator check is necessary because AttackBlockCallbacks
  9.   fire before the spectator check */
  10. if (state.isToolRequired() && !player.isSpectator() &&
  11. player.getMainHandStack().isEmpty()) {
  12. player.damage(DamageSource.field_5869, 1.0F);
  13. }
  14. return ActionResult.PASS;
  15. });
  16. }
  17. }

Fabric API Events

Player Interaction Events

Registry Events

Looting Events


There is an example of using LootTableLoadingCallback here.

World Events

Server Events

Network Events

C2SPacketTypeCallback / S2CPacketTypeCallback

See Event Index for a more complete and updated list.

tutorial/callbacks.txt · Last modified: 2024/05/20 16:05 by skycatminepokie