Building Assistant

Building Assistant is a client-and-server NeoForge mod for Minecraft 1.21.1 that provides an in-game workspace for planning structures before changing the world.

Use the Builder Tool to open a prompt and create a world-anchored ghost preview. The preview can be moved horizontally, raised or lowered, rotated, closed and reopened, or cancelled without placing or removing blocks.

Current Features

• In-game Builder Tool and prompt interface
• Deterministic structure preview
• World-anchored ghost blocks
• Horizontal movement and height adjustment
• Structure rotation
• Preview persistence when reopening the interface
• Safe cancellation without world changes
• Dedicated-server and multiplayer support

Early Preview Limitation

This release is intentionally non-mutating. The Finish action remains locked, so Building Assistant cannot place structures or alter the world.

Remote planning, automated construction, rollback, and provider integrations are not included in this version.

Requirements

• Minecraft 1.21.1
• NeoForge
• Installation on both the client and server