Multisource

Multisource is a tool for setting up a multiloader Minecraft modding development environment using source sets and feature variants to model different loaders. It works by allowing the definition, in the settings.gradle, of different source sets and information used to set up a subproject that uses architectury loom to set up Minecraft, remapping, and runs as necessary. The root project pulls a classpath from the subproject, and exposes its compiled classes to the subproject for runs, as well as bouncing through the subproject to create remapped jars.

To use, first set up the desired projects in your settings.gradle file:

pluginManagement {
    repositories {
        gradlePluginPortal()
        maven {
            name = 'Fabric'
            url = 'https://maven.fabricmc.net/'
        }
        maven {
            name = 'NeoForged'
            url = 'https://maven.neoforged.net'
        }
        maven {
            name = 'Architectury'
            url "https://maven.architectury.dev/"
        }
    }
}

plugins {
    id 'dev.lukebemish.multisource' version '<version>'
}

multisource.of(':') {
    configureEach {
        minecraft.add project.libs.minecraft
        mappings.add loom.officialMojangMappings()
    }
    common('main', []) {}
    fabric('fabric', ['main']) {}
    neoforge('neoforge', ['main']) {
        neoForge.add project.libs.neoforge
    }
}

The multisource.of block will set of the projects automatically, not requiring any manual configuration. The example above sets up the main source set as a common source set, and then sets up the fabric and neoforge source sets as the appropriate platforms. Both loader-specific source sets will automatically pull from the common main source set set up as a parent. Mapping and minecraft or loader dependency information may be specified in either the settings.gradle DSL as above, or by making build.gradle files for the generated subprojects and providing it there.

Next, you will want to set up feature variants and publishing in the root build.gradle:

plugins {
    id "maven-publish"
}

dependencies {
    modFabricImplementation libs.fabric.loader
    modFabricImplementation libs.fabric.api
}

java {
    withSourcesJar()
    registerFeature("neoforge") {
        usingSourceSet sourceSets.neoforge
        capability(project.group, project.name, project.version)
        capability(project.group, "$project.name-neoforge", project.version)
        withSourcesJar()
    }
    registerFeature("fabric") {
        usingSourceSet sourceSets.fabric
        capability(project.group, project.name, project.version)
        capability(project.group, "$project.name-fabric", project.version)
        withSourcesJar()
    }
}

publishing {
    publications {
        mavenJava(MavenPublication) {
            from components.java
        }
    }
}

Multisource sets up remapping configurations for fabric source sets, as well as include configurations for jar-in-jar in the fabric and neoforge source sets. By publishing with components.java, the different feature variants are included in the gradle module metadata with distinct capabilities.