DevKit API

🧰 DevKit API

A lightweight, modular toolkit for building Fabric mods with less boilerplate and more consistent infrastructure.

DevKit API is a developer-focused library for Minecraft 1.21.x. It brings together common systems that many mods need-registries, networking, Data Components, synchronized configuration, and data generation-behind small, reusable APIs.

It does not add gameplay content on its own. Players should install it only when another mod lists DevKit API as a dependency.

✨ What DevKit Provides

📦 Registry Kit

KRegister collects registry entries in declaration order and exposes them through typed RegistrySupplier references.

It provides:

• compact and type-safe declarations;
• duplicate identifier detection;
• clear errors when an entry is accessed too early;
• safe retry behavior after partial registration failures;
• registry-key-aware factories for blocks and items on newer Minecraft versions.

public static final KRegister<Item> ITEMS =
        KRegister.create("mymod", RegistryKeys.ITEM);

public static final RegistrySupplier<Item> RUBY =
        ITEMS.register("ruby", key ->
                new Item(new Item.Settings().registryKey(key)));

🌐 Payload Networking

DevKit builds on Fabric's Payload API while keeping client-only networking isolated from common and dedicated-server code.

Packet classes declare a stable ID, codec, and direction. AutoPacketRegistry validates that metadata, registers the payload, and connects the correct receiver for S2C or C2S traffic.

Included helpers cover common sending patterns:

• send to one player;
• send to players tracking a position;
• broadcast to all players;
• send from the client to the connected server.

@AutoPacket(
        value = "mymod:energy_sync",
        direction = AutoPacket.Direction.S2C
)
public record EnergySyncPacket(int energy) implements SyncedPacket {
    // ID, CODEC, and handler
}

Client receivers are wired automatically after packet registration, including packets registered later in initialization.

⚙️ Synchronized JSON Config

ConfigManager loads a readable JSON configuration or creates a default file when none exists.

Add @SyncedConfig to make a config server-authoritative. DevKit can then synchronize its values when a player joins and broadcast updates after a reload.

The config system supports:

• multiple named configs per mod;
• live updates without replacing the config object;
• safer file replacement where supported;
• malformed-file protection;
• synchronized payload size validation.

@SyncedConfig("mymod")
public final class MyConfig {
    public int maxEnergy = 10_000;
    public boolean enableParticles = true;
}

MyConfig config =
        ConfigManager.loadOrCreate(MyConfig.class, "mymod", "main");

🧩 Data Components

The Components API provides fluent builders around Minecraft's Data Component system.

Persistent codecs, packet codecs, caching, and registry insertion can be configured through one compact declaration.

public static final ComponentType<Integer> ENERGY =
        Components.intComponent("mymod", "energy")
                .cache()
                .buildAndRegister();

🗂️ Datagen Helpers

DevKit includes reusable foundations for frequently repeated data generation tasks:

• item and block models;
• block and item tags;
• common c: convention tags;
• block loot tables.

Version-specific implementations handle changes to Minecraft's client model system while keeping the public helper API consistent.

🔄 How It Fits Into a Mod

A dependent mod normally follows a simple lifecycle:

1. Declare registry containers, components, packets, and config classes.
2. Bootstrap registry entries from the mod initializer.
3. Register packet classes during common initialization.
4. Load configs through ConfigManager.
5. Use the networking and config helpers from normal gameplay code.

DevKit performs validation early and keeps physical-client code away from dedicated servers, reducing setup mistakes that otherwise appear only at runtime.

📚 Examples and Documentation

• Quick start and focused API examples
• Consumer setup and example usage
• Complete integration example
• Source code
• Issue tracker

The integration example is compiled with every supported build and demonstrates registry entries, Data Components, S2C/C2S packets, and synchronized configuration.

⚠️ Project Status

DevKit API is currently in alpha.

Its core systems are operational, but public API signatures may evolve before the stable release. Mod developers should pin the exact DevKit version used by their projects.

Created and maintained by jrxmod

Licensed under the Apache License 2.0.