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System Class

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Important

These APIs are experimental as part of the Beta APIs experiment. As with all experiments, you may see changes in functionality in updated Minecraft versions. Check the Minecraft Changelog for details on any changes to Beta APIs. Where possible, this documentation reflects the latest updates to APIs in Minecraft beta versions. A class that provides system-level events and functions.

Properties

afterEvents

read-only afterEvents: SystemAfterEvents;

Returns a collection of after-events for system-level operations.

Type: SystemAfterEvents

Caution

This property is still in pre-release. Its signature may change or it may be removed in future releases.

beforeEvents

read-only beforeEvents: SystemBeforeEvents;

Returns a collection of before-events for system-level operations.

Type: SystemBeforeEvents

Caution

This property is still in pre-release. Its signature may change or it may be removed in future releases.

currentTick

read-only currentTick: number;

Represents the current world tick of the server.

Type: number

Methods

clearRun

clearRun(runId: number): void

Cancels the execution of a function run that was previously scheduled via the run function.

Parameters

  • runId: number

run

run(callback: () => void): number

Runs a specified function at a future time. This is frequently used to implement delayed behaviors and game loops.

Parameters

  • callback: () => void

    Function callback to run when the tickDelay time criteria is met.

Returns number - An opaque identifier that can be used with the clearRun function to cancel the execution of this run.

Examples

trapTick.ts
  const overworld = mc.world.getDimension("overworld");

  try {
    // Minecraft runs at 20 ticks per second.
    if (mc.system.currentTick % 1200 === 0) {
      mc.world.sendMessage("Another minute passes...");
    }
  } catch (e) {
    console.warn("Error: " + e);
  }

  mc.system.run(trapTick);

runInterval

runInterval(callback: () => void, tickInterval?: number): number

Runs a set of code on an interval.

Parameters

  • callback: () => void

    Functional code that will run when this interval occurs.

  • tickInterval?: number = null

    An interval of every N ticks that the callback will be called upon.

Returns number - An opaque handle that can be used with the clearRun method to stop the run of this function on an interval.

Examples

every30Seconds.ts
  let intervalRunIdentifier = Math.floor(Math.random() * 10000);

  mc.system.runInterval(() => {
    mc.world.sendMessage("This is an interval run " + intervalRunIdentifier + " sending a message every 30 seconds.");
  }, 600);

runTimeout

runTimeout(callback: () => void, tickDelay?: number): number

Runs a set of code at a future time specified by tickDelay.

Parameters

  • callback: () => void

    Functional code that will run when this timeout occurs.

  • tickDelay?: number = null

    Amount of time, in ticks, before the interval will be called.

Returns number - An opaque handle that can be used with the clearRun method to stop the run of this function on an interval.