AsyncPrefab

AsyncPrefab is a server-side Hytale plugin that makes large prefab loading and pasting fully non-blocking.

Paste millions of blocks without freezing your server or crashing clients.

The Problem

Hytale’s built-in prefab system runs entirely on the world thread.

For large prefabs (4M+ blocks), this can cause:

Large-scale world editing becomes unstable and risky.

AsyncPrefab intercepts the prefab pipeline and makes everything asynchronous and batched.

When selecting a .prefab.json, the file loads on a background thread instead of the world thread.

Prefabs over ~4M blocks can generate packets too large for the client.

AsyncPrefab safely blocks these packets to prevent crashes.

Block placement is split into configurable batches (default: 50,000 blocks every 200ms).

Every async paste captures the original blocks.

Undo and redo are also processed in batches — no freezing.

After a paste completes, cached prefab data and selections are cleared to free memory.

Command	Description	Permission
`/paste`	Async replacement for the built-in paste	`hytale.editor.selection.clipboard`
`/asyncpaste <prefab> [x y z] [batchSize] [batchDelay]`	Load and paste a prefab asynchronously	`asyncprefab.paste`
`/asyncundo`	Undo last async paste	`asyncprefab.undo`
`/asyncredo`	Redo last undone async paste	`asyncprefab.redo`

All commands require Creative mode.

AsyncPrefab automatically intercepts the built-in Paste Tool.

Click to paste as normal — placement is automatically redirected to async batched processing.

No configuration required.

Works out of the box.

Tested with an 8.2 million block prefab:

AsyncPrefab exposes a service API for other plugins.

Example:

AsyncPrefabService service = Asyncprefab.getService();
service.paste(world, "my_prefab.prefab.json", position, PasteOptions.defaults());

Custom batch sizes and delays are configurable via PasteOptions.

MIT

Author: IPv5