multi3ify

All the regular Prism versions, plus Minecraft 1.7.10 with lwjgl3ify and Minecraft 1.12.2 with Cleanroom.

A Prism-compatible metadata feed, updated automatically.

./v1/

Set up once

  1. In Prism, open Settings → APIs → Services → Metadata Server and paste the URL above.
  2. Create an instance using 1.7.10-lwjgl3ify or 1.12.2-cleanroom. Leave the Mod Loader selection at None: its loader and runtime are installed automatically.
  3. For lwjgl3ify, install UniMixins (the combined jar, version 0.1.23 or newer) in the instance’s mods folder. For Cleanroom with a conventional Forge pack, install Fugue and Scalar Legacy.
  4. Launch. Keep Prism’s automatic Java selection and download enabled so it can supply a compatible Java runtime.

The launcher profile handles libraries and Java arguments. For lwjgl3ify, a small helper downloads and verifies its matching mod before the game starts, backing up existing copies. Cleanroom launches directly and includes MixinBooter and ConfigAnytime; no UniMixins or Relauncher is needed. Companion mods remain yours to manage.

Current Cleanroom releases use Java 25. Packs using Scala 3 mods need Scalar instead of Scalar Legacy. Do not install both providers.

Updates without moving jars

After creating an instance, open Edit Instance → Version → lwjgl3ify / Cleanroom → Change version to update, pin a release, or roll back. Choose latest for automatic updates, or a numbered release to stay on that version. lwjgl3ify follows stable releases; Cleanroom follows published releases, including alpha releases. The next launch uses the selected runtime.

New releases are checked every six hours. Restart Prism and reopen the instance’s Version tab if its metadata is cached. Each integration has its own release picker and adds one Minecraft profile and one loader entry.

Add to an existing instance

Set the metadata URL above, then open Edit Instance → Version → Minecraft → Change version and choose 1.7.10-lwjgl3ify. Prism switches the ordinary Forge component and adds lwjgl3ify in place. Your worlds, mods, and configuration stay in the same instance. Install UniMixins if needed and launch.

For an existing 1.12.2 instance, choose 1.12.2-cleanroom in the same Minecraft version dialog. Install Fugue and the appropriate Scalar provider, and review Cleanroom’s modpack migration guide for pack-specific compatibility changes. Your mods remain in place.

Change the Minecraft row to convert an ordinary instance. Changing only Forge leaves the old LWJGL 2 libraries installed, which conflict with the new LWJGL 3 runtime. If a previous attempt crashed mentioning PointerBuffer or CustomBuffer, complete the Minecraft selection above.

Keep automatic Java selection/download enabled and clear any forced Java 8 override. Existing local Minecraft/Forge, LWJGL, lwjgl3ify or Cleanroom component patches need to be reverted or removed first.

Already using multi3ify?

Restart Prism and open the instance’s Version tab. The old 10.13.4.1614-lwjgl3ify-latest Forge entry automatically adds the new lwjgl3ify row. Older numbered Forge entries keep working and stay pinned. To use the new picker with one, change Forge to 10.13.4.1614-lwjgl3ify-latest, then choose your desired release in the lwjgl3ify row before launching.

These are separate Minecraft entries so regular 1.7.10 and 1.12.2 keep their original requirements. The integrated mod browser searches for the real Minecraft version. Forks need custom metadata, component dependencies, JVM arguments, and Java management support.

Source and setup instructions · Metadata index · Build status · lwjgl3ify · Cleanroom