prefab-custom-addon
by veyne
Prefab, a NeoForge addon for Minecraft 1.20.1 and 1.21.1, lets players add custom building extension packs, with a browser for community-made packs and a local creator workspace.
What it does
Prefab ships with a handful of buildings, and its extension pack system lets players add more. Pressing Z in-game opens a downloader where community-made packs can be browsed and chosen; a chosen pack is saved as a prefab-extension and is ready to use the next time a world loads. Pressing X opens the creator, a local workspace mode for making a pack of one's own.
In the creator, a form takes a name, an NBT file, a cover image and a few further entries, which produces a standard extension pack. Everything the creator produces lives in the prefab-work folder inside the game root. Structures are exported as NBT files using the vanilla Structure Block. A pack can also be installed by hand by unzipping the file into prefab-extension.
Prefab requires LDLib, and the combination tested on NeoForge for Minecraft 1.21.1 with Java 21 uses LDLib2 2.2 or newer. The mod works with a dedicated server, and its environment is client and server.
Key features
Community pack browser
The Z downloader lists community-made extension packs, and a chosen pack is added to prefab-extension for later use.
Pack creator
The X creator fills a form from an NBT file and a cover image to produce a standard extension pack.
Workspace auto-repack
Changes in the prefab-work folder are repacked automatically into a ZIP, matching the published pack format.
Manual pack install
A pack can be installed by unzipping it into the prefab-extension folder without using the downloader.
Gallery
Compatibility
Latest build for each game version and loader.
Only full game releases are shown. This mod publishes no snapshot builds.
Requirements
Dependencies declared by the latest file for each loader.
Use cases
Who it’s for: Players who run out of the included buildings and want extra packs, and creators who build structures and want to share them as extension packs. Server owners need the mod on the server and on every client that connects.
Questions
Which loaders does Prefab support?
Does the server need Prefab installed?
Does Prefab need LDLib to run?
Where do packs made in the creator end up?
In the catalog
prefab-custom-addon is one of 8,016 Management mods on ModsFinder, and one of 2,698 Management mods for Forge. 32,366 mods support Minecraft 1.21.1.
Similar mods
What the author says
Prefab ships with a handful of buildings. After a while you get bored of them. This addon adds an extension pack system: press Z in-game to browse and download community-made packs, or press X to make your own.
Official listing
- Modrinth page
- modrinth.com/mod/prefab-custom-addon
- Owner
- veyne
- Published
- 2026-06-15
- Updated on Modrinth
- 2026-10-15
- Facts verified
- 2026-10-15
