Overview

Most powers can be built in a data pack with no code at all. You only need the Java API when JSON can't do the job: a new kind of power, a new action or condition, or a hook into game internals that no existing type exposes.

This part of the docs is for mod authors writing an Apoli addon. Origins is the main example: a mod that depends on Apoli and registers its own types on top.

When to use Java

If your idea rearranges things Apoli already does, stay in JSON. It is faster and needs no build.

How an addon is shaped

An Apoli addon is an ordinary Fabric or NeoForge mod that:

1. depends on Apoli at build time and at runtime,
2. registers its power types, actions and conditions during mod initialisation,
3. optionally ships a data pack of its own powers.

The package layout follows Apoli's own convention, with everything under dev.<you>.<modid>. The entrypoint, MyMod.java, registers everything, and power types, actions and conditions each get a package of their own:

dev/example/mymod/
├── MyMod.java
├── power/
├── action/
└── condition/

Depending on Apoli

Apoli is published for each loader and Minecraft version, and the version string says which, as in 1.118.1+1.21.1-fabric, 1.118.1+1.21.1-neoforge or 1.118.1+1.20.1-fabric. The group is dev.overgrown.apoli and the artifact is apoli. To build against an Apoli you compiled yourself, run its publishToMavenLocal task and add it in build.gradle, with apoli_version set to the full version string in gradle.properties:

repositories {
    mavenLocal()
}

dependencies {
    modImplementation "dev.overgrown.apoli:apoli:${apoli_version}"
}

Released builds are also on the Modrinth Maven repository (https://api.modrinth.com/maven) as maven.modrinth:opoli:<version>. On NeoForge, use implementation instead of modImplementation.

Then declare it in fabric.mod.json, or the NeoForge equivalent, so the game enforces it:

{
  "depends": {
    "apoli": ">=1.5.0"
  }
}

Next

• Getting started sets up a project and registers your first type.
• The cookbook has worked answers to the questions people ask most.
• Registering power types covers the core of an addon.
• Performance has the rules for code on a live server.

Reference map

Worked recipes