Worldgen Assist

Worldgen Assist is an experimental client-assisted terrain generation mod for Minecraft Java Edition 26.3. When an eligible new chunk needs terrain generation, a participating player's own PC can calculate a bounded terrain-density intermediate. The server checks the result and remains responsible for the final world state, including blocks, structures, fluids, saving, and gameplay.

The current alpha supports eligible new chunks in the vanilla Overworld, Nether, and End. It does not add biomes, dimensions, structures, or ores. Mod-added dimensions and custom generators are outside the verified scope.

Alpha status and safety

This release is intended for controlled tests with trusted participants and disposable worlds. Remote assistance is off by default. Enabling the 26.3 trusted route requires a separate explicit raw-seed disclosure choice; participating clients receive the world seed. Do not use that route when the seed must remain private or on an untrusted public server. The public-seed transcript fixture from the earlier 26.2 Fabric release is not available in 26.3.

Measured tests have not established a speedup. The selected 26.3 comparison showed slightly lower median throughput with assistance. The server falls back to normal local generation when remote work is unavailable or rejected.

Install

• Minecraft Java Edition 26.3 and Java 25.
• Choose one matching loader: Fabric Loader 0.19.5 with Fabric API 0.161.0+26.3, Forge 66.0.3, or NeoForge 26.3.0.13-beta.
• Install the same loader-specific Worldgen Assist JAR on the server and each participating client. Do not install a sources JAR or mix loader builds.
• Open Options → WorldgenAssist for the in-game settings. Client participation takes effect after reconnecting; saved server policy takes effect after a server restart.

Use a separate test profile and world while evaluating the alpha. Read the installation guide and verification record for tested scope and limitations.

Source code and issue reports: GitHub. Japanese overview.