Setting up Nylon

Merge these into your build.gradle file to add a dependency on Nylon.
Nylon requires certain Polymer modules aswell, which are included here.

repositories {
    maven { url "https://api.modrinth.com/maven" } // Nylon
    maven { url 'https://maven.nucleoid.xyz' } // Polymer
}

dependencies {
    modImplementation "maven.modrinth:nylon:[NYLON_VERSION]"

    modImplementation "eu.pb4:polymer-core:[POLYMER_VERSION]"
    modImplementation "eu.pb4:polymer-networking:[POLYMER_VERSION]"
    modImplementation "eu.pb4:polymer-resource-pack:[POLYMER_VERSION]"
    modImplementation "eu.pb4:polymer-virtual-entity:[POLYMER_VERSION]"

    // Useful for automatically handling resourcepacks in dev environment, but not required.
    modRuntimeOnly "eu.pb4:polymer-autohost:[POLYMER_VERSION]"
}

It is important to make sure these dependencies are available at runtime.
You can do this by either adding these modules to your dependencies in fabric.mod.json, or by including them in your jar file as Jar-in-Jar.

"nylon": "*",
"polymer-core": "*",
"polymer-networking": "*",
"polymer-virtual-entity": "*",
"polymer-resource-pack": "*"

Finally, make sure to add this in your mod initializer to tell Polymer to add your mods resource assets to the resourcepack.

PolymerResourcePackUtils.addModAssets("YOUR_MOD_ID");
PolymerResourcePackUtils.markAsRequired();