CoolCatLib¶

Write it once, run it everywhere, and make it look purr-fect.

The foundation and the visuals for multi-loader Minecraft mods: one common codebase for Fabric, NeoForge and Forge, with no Architectury API needed.

Get started API reference Source

Two mods, one toolkit¶

CoolCatLib: Core

coolcatcore · the purr-fect foundation. Entrypoints that replace per-loader setup; events, registration and networking; TOML configs with in-game screens; attachments; containers and storage menus.

Getting started
CoolCatLib: Canvas

coolcatcanvas · the cat's whiskers of visuals, built on Core. Live post-processing shaders, layered skyboxes, gradient and rainbow text, outlines, panels, pan & zoom views and easing curves.

Screen effects

Why CoolCatLib¶

Truly cross-loader

Your logic lives in common. Events, registries, payloads, menus and client registries are bridged to every loader.
No boilerplate payloads

Record payloads get their StreamCodec derived for you, from primitives to lists, maps, optionals and records.
Configs players love

Searchable screens with sliders, color pickers, undo/redo, themes and presets. Server values sync live.
Data on anything

Attachments on entities, block entities and item stacks, with sync policies, copy on death and change events.
Inventories done right

Slot roles, per-face access, automation-style transfer and texture-free storage menus.
Visuals without the pain

Shader effects with per-frame uniforms, layered skies, gradient text and outlines, all animated.

A thirty-second tour¶

MyMod.java — runs on Fabric, NeoForge and Forge alike

public class MyMod implements ModConstructor {
    public static final ConfigBuilder CONFIG = Config.builder("mymod", ConfigScope.SERVER);
    public static final ConfigValue<Integer> MAX_HOMES = CONFIG.intValue("maxHomes", 3).range(0, 64).slider().build();

    @Override
    public void onConstructMod() {
        CONFIG.build(); // (1)!
        Network.registerServerbound(PingPayload.class, (payload, context) -> // (2)!
                context.getPlayer().sendSystemMessage(Component.literal("Pong from " + payload.pos())));
        PlayerEvents.JOIN.register(player -> // (3)!
                player.sendSystemMessage(ColorGradient.RAINBOW.literal("Welcome, " + player.getName().getString() + "!")));
    }
}

public record PingPayload(BlockPos pos) implements CustomPacketPayload {
    public static final Type<PingPayload> TYPE = new Type<>(Identifier.fromNamespaceAndPath("mymod", "ping"));
    @Override public Type<PingPayload> type() { return TYPE; }
}

Registers and loads config/mymod-server.toml. Players can edit it in game, and its values sync to every client.
A record payload: CoolCatLib derives its network codec from the record's components.
An animated rainbow message, drawn by Canvas wherever the text shows up.

How it fits together¶

flowchart LR
    subgraph YourMod["Your mod"]
        C["common module<br/>ModConstructor · ClientModConstructor"]
        F["fabric"]
        N["neoforge / forge"]
    end
    subgraph CCL["CoolCatLib"]
        CORE["Core<br/>events · registries · network<br/>configs · attachments"]
        CANVAS["Canvas<br/>effects · skyboxes · text · GUI"]
    end
    F -- "coolcatcore:* entrypoints" --> C
    N -- "NeoForgeModEntrypoint<br/>ForgeModEntrypoint" --> C
    C --> CORE
    C --> CANVAS
    CANVAS --> CORE

Versions and loaders¶

Minecraft	NeoForge	Forge	Source
26.1 – 26.1.2		–	`26.1.2`
1.21 – 1.21.1			`1.21`
1.20.1	–		`1.20.1`

About these docs

The pages are written against 26.1.2. The backports share the same API, adjusted for their Minecraft version: ResourceLocation instead of Identifier, GuiGraphics instead of GuiGraphicsExtractor, and a Forge entrypoint.