Rosetta Library

Rosetta Library is a compatibility library for Minecraft mods that support multiple game versions and mod loaders from a shared codebase.

It provides compatibility helpers for registries, NBT, worlds, biomes, attributes, entities, textures, GUI rendering, gamerules, networking, and persistent attachments. Platform utilities are available for Fabric, Forge, and NeoForge.

Rosetta Library uses Stonecutter to maintain its version-specific implementations.

Support

MC Version	Fabric Version	Forge Version	NeoForge Version	Quilt Version
26.1	✅	❌	✅	❌
1.21.1	✅	❌	✅	❌
1.20.1	✅	✅	❌	❌

Building

Build every supported target:

.\gradlew.bat buildReleaseArtifacts

Target-specific jars are written to build/release.

Build one target:

.\gradlew.bat :1.21.1-fabric:build

Available targets are 26.1-fabric, 26.1-neoforge, 1.21.1-fabric, 1.21.1-neoforge, 1.20.1-fabric, and 1.20.1-forge.

Usage

See the developer usage guide for supported targets, networking examples, persistent attachments, and migration notes.

Maven

The target-specific artifacts are published from the maven branch:

repositories {
    maven("https://raw.githubusercontent.com/Rasa-Novum/Rosetta_Library/maven/")
}

dependencies {
    implementation("com.rasanovum.rosetta:rosetta-1.21.1-fabric:0.1.1")
}

Use the artifact matching the Minecraft version and loader: rosetta-1.20.1-fabric, rosetta-1.20.1-forge, rosetta-1.21.1-fabric, rosetta-1.21.1-neoforge, rosetta-26.1-fabric, or rosetta-26.1-neoforge.

Registries

Declare content once in common source. RegistryHandle is the same access type on every target, while ModRegistrar adapts Fabric’s eager registration and Forge/NeoForge deferred registration.

public final class ExampleContent {
    public static final ModRegistrar REGISTRAR = new ModRegistrar("example_mod");

    public static final ModRegistrar.BlockItemEntry<MachineBlock, MachineBlockItem> MACHINE =
            REGISTRAR.blockWithItem(
                    "machine",
                    MachineBlock::new,
                    BlockBehaviour.Properties.of().strength(3.0F),
                    MachineBlockItem::new,
                    new Item.Properties());

    public static final RegistryHandle<BlockEntityType<MachineBlockEntity>> MACHINE_ENTITY =
            REGISTRAR.blockEntity("machine", MachineBlockEntity::new, MACHINE.block());

    public static final RegistryHandle<BroadKnifeItem> BROAD_KNIFE =
            REGISTRAR.item("broad_knife", BroadKnifeItem::new, new Item.Properties());

    static {
        REGISTRAR.creativeTab(CreativeModeTabs.FUNCTIONAL_BLOCKS)
                .add(MACHINE)
                .addStacks("generated_machine_variants", output ->
                        createMachineVariantStacks().forEach(output::accept));

        REGISTRAR.creativeTab(CreativeModeTabs.TOOLS_AND_UTILITIES)
                .add(BROAD_KNIFE);
    }

    private ExampleContent() {}
}

Attach the registrar exactly once from each ordinary loader entrypoint:

// Fabric
ExampleContent.REGISTRAR.register(RegistrationContext.create());

// Forge / NeoForge
ExampleContent.REGISTRAR.register(RegistrationContext.create(modEventBus));

Use handle.get() wherever the registered value is needed. Calling it before that registry’s loader event finishes throws an error naming the unavailable identifier. register(BuiltInRegistries.SOME_REGISTRY, path, factory) covers other vanilla registries; paths are namespace-relative and duplicate paths in the same registry are rejected.

Creative-tab declarations are attached by the same single register(RegistrationContext) call. add(handle), add(BlockItemEntry), and add(ItemLike) cover ordinary entries. addStack(key, supplier) creates one dynamic stack per rebuild, while addStacks(key, output -> ...) can emit any number of configured variants. Entry and callback order is declaration order; duplicate entries or callback keys and declarations made after registrar attachment fail descriptively.