Fabric (Minecraft Modding)

Based on fabric-docs at commit 4313db4 (2026-08-05), targeting Minecraft 26.2 with Fabric Loader 0.19.x, Loom 1.16, Fabric API 0.155.2+26.2 and Mojang mappings (unobfuscated since 26.1). Generated on 2026-08-07.

Fabric is a lightweight modding toolchain for Minecraft: Java Edition built from three components: Fabric Loader (mod loading + class transformation), Fabric API (events, networking, registry helpers, datagen, tests), and Fabric Loom (the Gradle plugin that sets up the development environment). This skill covers the full developer workflow from project scaffolding to advanced rendering and porting.

Preferences

Target current Minecraft (26.x) with Mojang mappings; only use Yarn/remapping Loom for pre-26.1 versions.
Use modern APIs: data components over NBT, codecs over raw JSON, events over mixins, datagen over hand-written JSON.
Register everything in classes with static initializers called from entrypoints; keep client-only code in src/client.

Core & Setup

Topic	Description	Reference
Getting Started	Template generator, JDK 25, IDE setup, launching, sources, building	core-getting-started
Project Structure	Source sets, resources layout, entrypoints	core-project-structure
fabric.mod.json	Manifest spec: mandatory fields, entrypoints, dependencies, version ranges	core-fabric-mod-json
Fabric Loom	Gradle plugin: DSL options, dependency configurations, tasks, production runs	core-loom
Mappings & Migration	Yarn vs Mojang mappings, 26.1 unobfuscation, migrateMappings/Ravel	core-mappings-and-migration
Events	Listening to Fabric API events, loot table modification, custom events	core-events
Networking	Custom payloads, StreamCodecs, sending/receiving, PlayerLookup	core-networking
Text & Translations	Components, translatable text, serialization, ChatFormatting	core-text-and-translations
Testing & Debugging	Fabric Loader JUnit, game tests, CI, logging, breakpoints, crash logs	core-testing-and-debugging
Key Mappings & Game Rules	KeyMappingHelper, client tick reactions, custom game rules	core-key-mappings-and-game-rules

Items

Topic	Description	Reference
First Item	Registration, creative tab, name/texture/model/client item	items-first-item
Food	FoodProperties and Consumable effects	items-food
Potions	Custom potions and brewing recipes	items-potions
Spawn Eggs	SpawnEggItem registration and assets	items-spawn-egg
Tools & Armor	ToolMaterial, tools, ArmorMaterial, armor layers and equipment models	items-tools-and-armor
Item Models & Appearance	Model JSON structure, display transforms, custom tint sources	items-models-and-appearance
Creative Tabs	FabricCreativeModeTab builder and registration	items-creative-tabs
Interactions & Enchantments	use/useOn overrides, custom enchantment effects	items-interactions-and-enchantments
Data Components	Custom DataComponentType, composite components, tooltips	items-data-components

Blocks

Topic	Description	Reference
First Block	Registration with/without item, assets, loot tables, tool tags	blocks-first-block
Block States & Models	Properties, blockstate JSON, model elements, tinting	blocks-blockstates-and-models
Block Entities	Types, NBT save/load, client sync, tickers, BERs	blocks-block-entities
Containers & Menus	Container/WorldlyContainer, menus, screens, workstations	blocks-containers

Fluids

Topic	Description	Reference
First Fluid	Source/flowing states, liquid block, bucket, tags, rendering	fluids-first-fluid

Entities

Topic	Description	Reference
First Entity	Registration, goals, models, renderers, animations, synced data	entities-first-entity
Attributes	Custom attributes, attach/read/modify	entities-attributes
Effects & Damage	Custom mob effects, data-driven damage types, death messages, tags	entities-effects-and-damage

Sounds

Topic	Description	Reference
Playing & Custom Sounds	SoundEvents, categories, volume/pitch, sounds.json	sounds-using-and-custom
Dynamic Sounds	Client SoundInstances: looping, tracking sources, transitions	sounds-dynamic

Commands

Topic	Description	Reference
Commands & Suggestions	Brigadier basics, requirements, sub-commands, client commands, suggestions	commands-basics-and-suggestions
Arguments	Built-in arguments, optional args, custom ArgumentType	commands-arguments

Recipes

Topic	Description	Reference
Custom Recipe Types	RecipeInput, Recipe, serializers, recipe book hooks, sync	recipes-custom-types
Extending Vanilla Recipes	Smithing/Crafting/Stonecutter recipe extensions	recipes-extending-vanilla

Rendering

Topic	Description	Reference
Basic Concepts	BufferBuilder, vertex formats, matrices, quaternions, render pipelines	rendering-basic-concepts
GUI, Screens & Widgets	GuiGraphicsExtractor, scissor, textures/text, custom screens/widgets	rendering-gui
HUD	HudElementRegistry, DeltaTracker partial ticks	rendering-hud
World & Particles	LevelRenderEvents, extraction/drawing phases, custom particles	rendering-world-and-particles

Data Generation

Topic	Description	Reference
Setup	fabric-datagen entrypoint, Pack, providers, runDatagen	datagen-setup
Models & Translations	Language provider, block/item models, client items	datagen-models-and-translations
Server Data	Recipes, tags, loot tables, advancements, enchantments	datagen-server
World Generation	Configured/placed features, placement modifiers, biome modifications	datagen-features

Serialization

Topic	Description	Reference
Codecs	Building/composing/transforming codecs, dispatch, stream codecs	serialization-codecs
Data Attachments	Attaching synced/persistent data to entities/levels/chunks	serialization-data-attachments
Saved Data	Level-scoped persistent data with SavedData	serialization-saved-data

Mixins & Class Tweakers

Topic	Description	Reference
JVM Bytecode	Descriptors, LVT, operand stack, common instructions	mixins-bytecode
Accessors & Invokers	@Accessor/@Invoker for fields, methods, constructors	mixins-accessors
Class Tweakers	Access widening, interface injection, enum extension	class-tweakers

Porting & Misc

Topic	Description	Reference
Porting & Updates	Version bumps, unobfuscation switch, Fabric API rename maps	porting-and-updates
Resource Conditions & Stats	Conditional loading, custom statistics	misc-resource-conditions-and-statistics

Quick Reference

Minimal build.gradle (Minecraft 26.2)

plugins { id 'net.fabricmc.fabric-loom' version '1.16' }

dependencies {
  minecraft "com.mojang:minecraft:26.2"
  mappings loom.officialMojangMappings()
  modImplementation "net.fabricmc.fabric-api:fabric-api:0.155.2+26.2"
  implementation "net.fabricmc:fabric-loader:0.19.2"
}

loom {
  splitEnvironmentSourceSets()
  mods { "example-mod" { sourceSet sourceSets.main; sourceSet sourceSets.client } }
}

Minimal fabric.mod.json

{
  "schemaVersion": 1,
  "id": "example-mod",
  "version": "1.0.0",
  "entrypoints": {
    "main": ["com.example.ExampleMod"],
    "client": ["com.example.ExampleModClient"]
  },
  "depends": {
    "fabricloader": ">=0.19.0",
    "minecraft": "~26.2",
    "java": ">=25",
    "fabric-api": "*"
  }
}

Common Commands

./gradlew runClient        # dev run
./gradlew build            # build release JAR (build/libs)
./gradlew genSources       # decompile Minecraft sources
./gradlew runDatagen       # run data generation
./gradlew runClientGameTest # client game tests
./gradlew validateAccessWidener # validate class tweaker entries

Key API Notes

Registration: Registry.register(BuiltInRegistries.X, Identifier.fromNamespaceAndPath("mod", "name"), value).
26.x uses Mojang names: Level (not World), BlockPos, ItemStack, Item.Properties, BlockBehaviour.Properties, FriendlyByteBuf.
Entrypoints: ModInitializer, ClientModInitializer, DedicatedServerModInitializer, DataGeneratorEntrypoint (fabric-datagen).