@opys/cleanroom

Cleanroom for opys. cleanroom() adds Minecraft 1.12.2 with Cleanroom: Forge 1.12.2 mods on a modern Java. Use it instead of minecraft().

npm install -D @opys/dev @opys/cleanroom @opys/java

Example

// opys.config.mjs
import { defineConfig } from '@opys/dev';
import { cleanroom } from '@opys/cleanroom';
import { java } from '@opys/java';

export default defineConfig({
  output: 'game.opys',
  plugins: [cleanroom({ version: '1.12.2' }), java({ version: '25' })],
  manifest: {
    command: '@cleanroom.command',
    args: ['@cleanroom.jvmArgs', '@cleanroom.mainClass', '@cleanroom.gameArgs'],
    workdir: '${game_directory}',
  },
});

Options

Option	What it does
version	'1.12.2' (recommended release), '1.12.2-latest', or an exact '0.6.13-alpha'.
source	A mirror of the build index.
libraries	Libraries to add or replace, each { name, artifact }.

version is resolved when you build, so anything but an exact build can change between two builds.

What it adds

Everything @opys/minecraft-vanilla adds (the game, its variables), with these differences.

Files · the game and Cleanroom libraries

The 1.12.2 game, with LWJGL 2 swapped for LWJGL 3. The old one is not installed at all.

// in the manifest
{
  "path": "${library_directory}/com/cleanroommc/cleanroom/0.6.13-alpha/cleanroom-0.6.13-alpha.jar",
  "source": { "url": "https://github.com/CleanroomMC/Cleanroom/releases/download/0.6.13-alpha/cleanroom-0.6.13-alpha-universal.jar" },
  "size": 6505649,
  "integrity": { "sha1": "8d59eda7065f26fc0c1bbd3a9fa9f272ff89917f" }
}

Launch

A short line, started through Cleanroom's own main class. Nothing runs before the game.

// in the manifest
"launch": {
  // '@cleanroom.command'
  "command": "${java_bin}",
  "args": [
    // '@cleanroom.jvmArgs'
    "-Djava.library.path=${natives_directory}",
    "-cp",
    "${classpath}",
    // '@cleanroom.mainClass'
    "top.outlands.foundation.boot.Foundation",
    // '@cleanroom.gameArgs'
    "--username", "${auth_player_name}",
    // … the rest of the 1.12.2 game arguments, then:
    "--tweakClass", "net.minecraftforge.fml.common.launcher.FMLTweaker",
    "--versionType", "Forge"
  ],
  "workdir": "${game_directory}"
}

Variables

The same names as vanilla. classpath has the loader's libraries ahead of the game's.

// in the manifest
"vars": {
  "classpath": [/* the loader's libraries, the game's, then the game jar */]
  // … the rest, as in vanilla
}

Every option

Each option, in each way it is used.

// the recommended release for a Minecraft version, or the newest if none is
cleanroom({ version: '1.12.2' });
cleanroom({ version: '1.12.2-recommended' });

// the newest release
cleanroom({ version: '1.12.2-latest' });

// one exact release: the same in every build of the pack
cleanroom({ version: '0.6.13-alpha' });

// a library the game does not ship, or a patched copy of one it does
cleanroom({
  version: '1.12.2',
  libraries: [
    // a jar next to the config: it travels inside the bundle
    {
      name: 'com.google.code.gson:gson:2.11.0',
      artifact: {
        path: 'com/google/code/gson/gson/2.11.0/gson-2.11.0.jar',
        source: { file: 'libs/gson-2.11.0.jar' },
      },
    },
    // a jar by link, for one OS only
    {
      name: 'com.example:native-helper:1.0',
      artifact: {
        path: 'com/example/native-helper/1.0/native-helper-1.0.jar',
        source: { url: 'https://example.com/native-helper-1.0.jar' },
        integrity: { sha1: 'da39a3ee5e6b4b0d3255bfef95601890afd80709' },
        rules: 'allow.os.windows',
      },
    },
  ],
});

// mirrors, for a network that cannot reach the defaults
cleanroom({
  version: '1.12.2',
  source: 'https://mirror.example.com/cleanroom',
});

Documentation

• The full page: every option, and why it works this way
• The format: what a manifest is made of

Part of opys. Also exported by @opys/minecraft.