MultiMC.md

JSON patches for MultiMC instances

This allows changing the Minecraft version in the instance without re-editing the component, and easier interoperability with other MultiMC features. More information about JSON patches can be found on the MultiMC wiki page about them.

Important

Please obtain a build of LaunchWrapper And place it in <MultiMC directory>/libraries/org/mcphackers/launchwrapper/1.0-SNAPSHOT/launchwrapper-1.0-SNAPSHOT.jar, as it is currently not recommended to use versioned release. Use latest git commit whenever possible.

Instructions

• Create a new MultiMC instance.

• Click "Edit Instance".

• Click "Add Empty". Enter "LaunchWrapper" for the name, and "org.mcphackers.launchwrapper" for the UUID.

• Select the new component labeled "LaunchWrapper", and click "Edit".

• Replace the contents of the file with something like this:

  Show JSON

  {
      "+traits": [
          "noapplet"
      ],
      "libraries": [
          {
              "downloads": {},
              "name": "org.mcphackers:launchwrapper:1.0-SNAPSHOT"
          },
          {
              "name": "org.ow2.asm:asm:9.7",
              "url": "https://repo1.maven.org/maven2/"
          },
          {
              "name": "org.ow2.asm:asm-tree:9.7",
              "url": "https://repo1.maven.org/maven2/"
          },
          {
              "name": "org.json:json:20240303",
              "url": "https://repo1.maven.org/maven2/"
          }
      ],
      "mainClass": "org.mcphackers.launchwrapper.Launch",
      "minecraftArguments": "--username ${auth_player_name} --session ${auth_session} --version ${version_name} --gameDir ${game_directory} --assetsDir ${assets_root} --assetIndex ${assets_index_name} --accessToken ${auth_access_token} --userType ${user_type} --versionType ${version_type}",
      "requires": [
          {
              "uid": "net.minecraft"
          }
      ],
      "formatVersion": 1,
      "name": "LaunchWrapper",
      "uid": "org.mcphackers.launchwrapper",
      "version": "1.0-SNAPSHOT"
  }

  (If you're using Prism Launcher all previous steps can be skipped. Use "Import Components" button and locate the aforementioned JSON)

  For the library with empty downloads key you need to build LaunchWrapper manually using gradle wrapper. Just open command prompt and run ./gradlew build in the root of this project, then put built library from build/libs/launchwrapper-1.0-SNAPSHOT.jar to <MutltiMC root>/libraries/org/mcphackers/launchwrapper/1.0-SNAPSHOT/launchwrapper-1.0-SNAPSHOT.jar

• Save and close the document.