---
title: Tasks
type: docs
weight: 3
---

The task system in Hytale manages asynchronous operations using Java's standard concurrency APIs.

{{< cards >}}
  {{< card link="task-registry" title="TaskRegistry" subtitle="Registering and tracking tasks" >}}
  {{< card link="async-operations" title="Async Operations" subtitle="Thread-safe async patterns" >}}
{{< /cards >}}

## Overview

{{< callout type="warning" >}}
**Important:** TaskRegistry does NOT have `runAsync()`, `runSync()`, `runLater()`, or `runRepeating()` methods. Hytale uses Java's standard `CompletableFuture` and `ScheduledExecutorService` APIs.
{{< /callout >}}

The TaskRegistry allows plugins to:
- **Register tasks** - Track `CompletableFuture` and `ScheduledFuture` for cleanup
- **Async operations** - Use `CompletableFuture.runAsync()`
- **Delayed operations** - Use `CompletableFuture.delayedExecutor()`
- **Repeating operations** - Use `ScheduledExecutorService`

## Quick Start

```java
// Run async operation
CompletableFuture.runAsync(() -> {
    // Background thread code
    Data result = computeExpensiveData();

    // Return to world thread for game state changes
    world.execute(() -> {
        playerRef.sendMessage(Message.raw("Result: " + result));
    });
});

// Delayed operation (3 seconds)
CompletableFuture.delayedExecutor(3, TimeUnit.SECONDS)
    .execute(() -> {
        world.execute(() -> {
            // Delayed code on world thread
        });
    });
```

## Key Concepts

{{< callout type="warning" >}}
**Thread Safety:** Each World runs on its own dedicated thread. Always use `world.execute()` when modifying game state (players, entities, blocks) from async code. Direct manipulation from async threads can cause crashes or data corruption.
{{< /callout >}}

```java
// Correct pattern
PlayerRef playerRef = player.getPlayerRef();
World world = player.getWorld();

CompletableFuture.runAsync(() -> {
    // Do heavy computation here (background thread)
    Data result = computeExpensiveData();

    // Return to world thread for game state changes
    world.execute(() -> {
        playerRef.sendMessage(Message.raw("Result: " + result));
    });
});
```