A comprehensive Fabric API library for Minecraft 1.21.10 that eliminates boilerplate and accelerates mod development.
Mosberg API is a developer library mod that provides:
✅ 16+ Registry Classes - Register blocks, items, entities, enchantments, fluids, sounds, particles, and more with minimal code
✅ 25+ Utility Helpers - Production-ready helpers for inventory, entities, NBT, particles, world manipulation, and more
✅ 8 Built-in Commands - Block, item, entity, world, debug, config, registry, and help commands out of the box
✅ Advanced Client Systems - Entity rendering, model management, screen handlers, and 1.21+ render state support
✅ Fluent Data Generation - Auto-generate recipes, loot tables, and models with intuitive builders
✅ Event System - Custom events for block mining, player joining, entity spawning
✅ JSON Configuration - Built-in config management with automatic file generation
✅ Modern Java 21 - Records, pattern matching, sealed classes, and null safety annotations
No gameplay content is added to Minecraft. Mosberg API is purely a developer library for mod creators.
.minecraft/mods/ folderAdd to gradle.properties:
# Dependencies
mosberg_api_1412900_version=7375365Add to build.gradle:
repositories {
maven {
name = "CurseMaven"
url = "https://cursemaven.com/"
content {
includeGroup "curse.maven"
}
}
}
dependencies {
// Mosberg API
modImplementation "curse.maven:mosberg-api-1412900:${project.mosberg_api_1412900_version}"
// Optional: bundle with your mod
include implementation("curse.maven:mosberg-api-1412900:${project.mosberg_api_1412900_version}")
}Update fabric.mod.json:
{
"depends": {
"mosberg-api": "*"
}
}Create your mod initializer:
import net.fabricmc.api.ModInitializer;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class YourMod implements ModInitializer {
public static final String MOD_ID = "yourmod";
public static final Logger LOGGER = LoggerFactory.getLogger(MOD_ID);
@Override
public void onInitialize() {
LOGGER.info("YourMod initialized with Mosberg API!");
// Register your content
ModBlocks.initialize();
ModItems.initialize();
ModEntities.initialize();
// Register events
ModEvents.register();
// Load config
ModConfig.load();
}
}Simplify registration with one-liners:
// Block registration (auto-creates item)
public static final Block RUBY_BLOCK = MosbergBlocks.register(
"ruby_block",
new Block(AbstractBlock.Settings.create().strength(2.0f))
);
// Entity registration
public static final EntityType<CustomMob> CUSTOM_MOB = MosbergEntities.register(
"custom_mob",
EntityType.Builder.create(CustomMob::new, SpawnGroup.CREATURE)
.dimensions(0.8f, 1.8f)
);
// Enchantment registration
public static final Enchantment CUSTOM_ENCH = MosbergEnchantments.register(
"custom_ench",
new Enchantment(...)
);16 Registry Classes:
25+ helpers for common operations:
// Inventory operations
ItemStack leftovers = InventoryHelper.addItemToInventory(inv, stack);
int transferred = InventoryHelper.transferItems(source, dest, count);
boolean hasSpace = InventoryHelper.hasSpace(inv, stack);
// Entity manipulation
EntityHelper.teleportEntity(entity, world, pos);
EntityHelper.applyKnockback(entity, strength, direction);
EntityHelper.healEntity(entity, amount);
// World operations
WorldHelper.setRaining(world, duration);
WorldHelper.createExplosion(world, null, pos, power, true);
List<Entity> nearby = WorldHelper.getEntitiesInBox(world, box);
// NBT operations
NBTHelper.setString(nbt, "name", value);
NBTHelper.setInt(nbt, "level", 5);
String name = NBTHelper.getString(nbt, "name", "Default");
// Particle effects
ParticleHelper.spawnParticles(world, ParticleTypes.FLAME, pos, count, spread);All 25 Helpers: AttributeHelper, BlockHelper, CommandHelper, DataComponentHelper, DamageTypeHelper, EnchantmentUtil, EntityHelper, FluidHelper, GameEventHelper, InventoryHelper, ItemGroupHelper, ItemHelper, MosbergEnchantmentHelper, MosbergHelper, NBTHelper, NetworkHelper, ParticleHelper, PotionHelper, RecipeHelper, SerializationHelper, SoundHelper, StatusEffectHelper, TagHelper, VillagerHelper, WorldHelper
Fluent builders for recipes and loot tables:
// Shaped crafting
createShaped(RecipeCategory.TOOLS, ModItems.SWORD)
.pattern(" I ")
.pattern(" I ")
.pattern(" S ")
.input('I', Items.IRON_INGOT)
.input('S', Items.STICK)
.criterion(hasItem(Items.IRON_INGOT), conditionsFromItem(Items.IRON_INGOT))
.offerTo(exporter);
// Smelting
offerSmelting(exporter, List.of(ModBlocks.ORE),
RecipeCategory.MISC, ModItems.INGOT, 1.0f, 200, "ingot");
// Stonecutting
createStonecutting(RecipeCategory.BUILDING_BLOCKS, ModBlocks.STAIRS, ModBlocks.BLOCK)
.criterion(hasItem(ModBlocks.BLOCK), conditionsFromItem(ModBlocks.BLOCK))
.offerTo(exporter);
// Loot tables
addBlockLootTable(ModBlocks.ORE,
LootTable.builder()
.pool(LootPool.builder()
.rolls(ConstantLootNumberProvider.create(1))
.with(ItemEntry.builder(ModItems.INGOT))));8 production-ready commands:
/block - Inspect and modify block properties/item - Manage items and NBT data/entity - Spawn and manipulate entities/world - Control weather, time, explosions/debug - Performance profiling and analysis/config - Manage configuration at runtime/registry - Introspect registered content/help - Command documentationEasy entity and screen registration:
// Register entity renderer
MosbergRenderers.registerEntityRenderer(
ModEntities.CUSTOM_MOB,
CustomMobRenderer::new,
ModModelLayers.CUSTOM_MOB,
CustomMobModel::getTexturedModelData
);
// Register screen
ScreenRegistry.register(ModScreenHandlers.CUSTOM,
CustomScreen::new);Client utilities:
Custom event callbacks:
MosbergEvents.BLOCK_MINED.register((player, world, pos, state) -> {
if (state.isOf(Blocks.DIAMOND_ORE)) {
player.sendMessage(Text.literal("You mined diamonds!"), false);
}
});
MosbergEvents.PLAYER_JOINED.register((player) -> {
LOGGER.info("Player joined: {}", player.getName().getString());
});
MosbergEvents.ENTITY_SPAWNED.register((entity, world) -> {
LOGGER.debug("Entity spawned: {}", entity.getType());
});JSON-based config with defaults:
public class ModConfig {
public static final ConfigManager CONFIG = new ConfigManager("yourmod");
public static int SPAWN_RATE = 10;
public static boolean ENABLE_FEATURE = true;
public static double DAMAGE_MULTIPLIER = 1.5;
public static void load() {
SPAWN_RATE = CONFIG.getInt("spawn_rate", 10);
ENABLE_FEATURE = CONFIG.getBoolean("enable_feature", true);
DAMAGE_MULTIPLIER = CONFIG.getDouble("damage_multiplier", 1.5);
CONFIG.save();
}
}Register blocks, items, entities, enchantments, fluids, sounds, particles, status effects, potions, block entities, data components, damage types, game events, screen handlers, villagers, world generation, and tags.
Inventory, entities, NBT, particles, world state, blocks, attributes, commands, enchantments, fluids, game events, item groups, networking, potions, recipes, serialization, sounds, status effects, tags, and villagers.
Block, item, entity, world, debug, config, registry, and help commands ready to use or extend.
Entity renderers, model management, screen handlers, render states (1.21+), and rendering utilities.
Fluent builders for recipes, loot tables, and models with full Minecraft 1.21.10 support.
BlockMined, PlayerJoined, EntitySpawned, and more with simple registration.
JSON-based config system with auto-generation and reload support.
Full documentation available at:
build.gradlefabric.mod.json with Mosberg API dependencyModInitializer./gradlew buildFull examples and tutorials available on the GitHub Wiki.
✅ Zero Boilerplate - Register anything with one line
✅ Type-Safe - Modern Java 21 with full null safety
✅ Production-Ready - 25+ tested utility helpers
✅ Fluent APIs - Intuitive builder patterns
✅ Comprehensive - Covers 60+ Minecraft registry types
✅ Well-Documented - Every method has clear Javadoc
✅ Active Development - Regular updates and improvements
✅ Community-Driven - Open to feedback and contributions
MIT License - Use in commercial projects, modify, distribute, or use for educational purposes. Attribution appreciated but not required.
Need help?
Want to contribute?
✨ Mod developers who want to spend more time on gameplay and less on boilerplate
✨ Library mods that need a solid foundation
✨ Teams building content packs with custom mechanics
✨ Anyone using Fabric API 1.21.10+
Mosberg API - Write less boilerplate. Build better mods. Faster.
Made with ❤️ by Mosberg for the Minecraft modding community
**Production-ready Fabric library** for Minecraft 1.21.11 providing 28 utility helpers + 6 fluent builders. Designed as a dependency for other mods; no gameplay features—pure API library.
**Production-ready Fabric library** for Minecraft 1.21.11 providing 28 utility helpers + 6 fluent builders. Designed as a dependency for other mods; no gameplay features—pure API library.