# Simple Mod Template > Simple MOD Template (MC 1.21.11 / Forge 61.2.0) - Skill: `zmjjkk123-hub/simple-mod-template` (Agent Skill) - Install (CLI): `npx skillmds@latest add zmjjkk123-hub/simple-mod-template` - Raw SKILL.md: https://api.skillmd.com/api/skills/zmjjkk123-hub/simple-mod-template/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Coding & Dev Tools - Author: ZMJJKK123-hub (https://skillmd.com/u/zmjjkk123-hub) - Updated: 2026-09-22 - Page: https://skillmd.com/skills/zmjjkk123-hub/simple-mod-template --- # Simple MOD Template (MC 1.21.11 / Forge 61.2.0) This template is a **known-working** simple MOD. Copy these files into the session mod project and replace names as needed. ## How to use 1. Keep the package `com.example.examplemod` and mod id `examplemod` unless the task requires different. 2. Replace `test_item` / `example_block` with your item/block names. 3. Create the files below. 4. Run `gradlew build`; if GameTest is required, also run `run_test_gametest`. --- ## `src/main/java/com/example/examplemod/ExampleMod.java` ```java package com.example.examplemod; import com.mojang.logging.LogUtils; import net.minecraft.client.Minecraft; import net.minecraft.core.registries.Registries; import net.minecraft.world.food.FoodProperties; import net.minecraft.world.item.BlockItem; import net.minecraft.world.item.CreativeModeTab; import net.minecraft.world.item.CreativeModeTabs; import net.minecraft.world.item.Item; import net.minecraft.world.level.block.Block; import net.minecraft.world.level.block.Blocks; import net.minecraft.world.level.block.state.BlockBehaviour; import net.minecraft.world.level.material.MapColor; import net.minecraftforge.api.distmarker.Dist; import net.minecraftforge.event.BuildCreativeModeTabContentsEvent; import net.minecraftforge.eventbus.api.listener.SubscribeEvent; import net.minecraftforge.fml.common.Mod; import net.minecraftforge.fml.config.ModConfig; import net.minecraftforge.fml.event.lifecycle.FMLClientSetupEvent; import net.minecraftforge.fml.event.lifecycle.FMLCommonSetupEvent; import net.minecraftforge.fml.javafmlmod.FMLJavaModLoadingContext; import net.minecraftforge.registries.DeferredRegister; import net.minecraftforge.registries.ForgeRegistries; import net.minecraftforge.registries.RegistryObject; import org.slf4j.Logger; @Mod(ExampleMod.MODID) public final class ExampleMod { public static final String MODID = "examplemod"; private static final Logger LOGGER = LogUtils.getLogger(); public static final DeferredRegister BLOCKS = DeferredRegister.create(ForgeRegistries.BLOCKS, MODID); public static final DeferredRegister ITEMS = DeferredRegister.create(ForgeRegistries.ITEMS, MODID); public static final DeferredRegister CREATIVE_MODE_TABS = DeferredRegister.create(Registries.CREATIVE_MODE_TAB, MODID); public static final RegistryObject EXAMPLE_BLOCK = BLOCKS.register("example_block", () -> new Block(BlockBehaviour.Properties.of() .setId(BLOCKS.key("example_block")) .mapColor(MapColor.STONE) ) ); public static final RegistryObject EXAMPLE_BLOCK_ITEM = ITEMS.register("example_block", () -> new BlockItem(EXAMPLE_BLOCK.get(), new Item.Properties().setId(ITEMS.key("example_block"))) ); public static final RegistryObject TEST_ITEM = ITEMS.register("test_item", () -> new Item(new Item.Properties().setId(ITEMS.key("test_item"))) ); public static final RegistryObject EXAMPLE_TAB = CREATIVE_MODE_TABS.register("example_tab", () -> CreativeModeTab.builder() .withTabsBefore(CreativeModeTabs.COMBAT) .icon(() -> TEST_ITEM.get().getDefaultInstance()) .displayItems((parameters, output) -> { output.accept(TEST_ITEM.get()); output.accept(EXAMPLE_BLOCK_ITEM.get()); }).build()); public ExampleMod(FMLJavaModLoadingContext context) { var modBusGroup = context.getModBusGroup(); FMLCommonSetupEvent.getBus(modBusGroup).addListener(this::commonSetup); BLOCKS.register(modBusGroup); ITEMS.register(modBusGroup); CREATIVE_MODE_TABS.register(modBusGroup); BuildCreativeModeTabContentsEvent.BUS.addListener(ExampleMod::addCreative); context.registerConfig(ModConfig.Type.COMMON, Config.SPEC); } private void commonSetup(final FMLCommonSetupEvent event) { LOGGER.info("HELLO FROM COMMON SETUP"); if (Config.logDirtBlock) LOGGER.info("DIRT BLOCK >> {}", ForgeRegistries.BLOCKS.getKey(Blocks.DIRT)); LOGGER.info(Config.magicNumberIntroduction + Config.magicNumber); Config.items.forEach((item) -> LOGGER.info("ITEM >> {}", item.toString())); } private static void addCreative(BuildCreativeModeTabContentsEvent event) { if (event.getTabKey() == CreativeModeTabs.BUILDING_BLOCKS) event.accept(EXAMPLE_BLOCK_ITEM); } @Mod.EventBusSubscriber(modid = MODID, value = Dist.CLIENT) public static class ClientModEvents { @SubscribeEvent public static void onClientSetup(FMLClientSetupEvent event) { LOGGER.info("HELLO FROM CLIENT SETUP"); LOGGER.info("MINECRAFT NAME >> {}", Minecraft.getInstance().getUser().getName()); } } } ``` --- ## Item model definitions (MUST create for every item/block item) ### `src/main/resources/assets/examplemod/items/test_item.json` ```json { "model": { "type": "minecraft:model", "model": "examplemod:item/test_item" } } ``` ### `src/main/resources/assets/examplemod/items/example_block.json` ```json { "model": { "type": "minecraft:model", "model": "examplemod:item/example_block" } } ``` --- ## Item / block models ### `src/main/resources/assets/examplemod/models/item/test_item.json` ```json { "parent": "minecraft:item/generated", "textures": { "layer0": "examplemod:item/test_item" } } ``` ### `src/main/resources/assets/examplemod/models/item/example_block.json` ```json { "parent": "examplemod:block/example_block" } ``` ### `src/main/resources/assets/examplemod/models/block/example_block.json` ```json { "parent": "minecraft:block/cube_all", "textures": { "all": "examplemod:block/example_block" } } ``` ### `src/main/resources/assets/examplemod/blockstates/example_block.json` ```json { "variants": { "": { "model": "examplemod:block/example_block" } } } ``` --- ## Lang ### `src/main/resources/assets/examplemod/lang/en_us.json` ```json { "item.examplemod.test_item": "Test Item", "block.examplemod.example_block": "Example Block", "itemGroup.examplemod.example_tab": "Example Mod" } ``` ### `src/main/resources/assets/examplemod/lang/zh_cn.json` ```json { "item.examplemod.test_item": "测试物品", "block.examplemod.example_block": "示例方块", "itemGroup.examplemod.example_tab": "示例模组" } ``` --- ## Recipe (MC 1.21.11: ingredients are plain strings) ### `src/main/resources/data/examplemod/recipe/test_item.json` ```json { "type": "minecraft:crafting_shapeless", "category": "misc", "ingredients": [ "minecraft:stick", "minecraft:iron_ingot" ], "result": { "id": "examplemod:test_item", "count": 1 } } ``` --- ## Textures Generate simple 16x16 textures with a script: ```python from PIL import Image, ImageDraw import os def make_item(path): os.makedirs(os.path.dirname(path), exist_ok=True) img = Image.new('RGBA', (16, 16), (0, 0, 0, 0)) d = ImageDraw.Draw(img) d.rectangle([6, 1, 9, 10], fill=(0, 200, 255)) d.rectangle([7, 0, 8, 1], fill=(0, 200, 255)) d.rectangle([5, 10, 10, 12], fill=(139, 90, 43)) d.rectangle([6, 12, 9, 13], fill=(255, 215, 0)) d.rectangle([7, 13, 8, 15], fill=(100, 60, 20)) img.save(path, 'PNG') def make_block(path): os.makedirs(os.path.dirname(path), exist_ok=True) img = Image.new('RGB', (16, 16), (128, 128, 128)) d = ImageDraw.Draw(img) d.rectangle([2, 2, 6, 6], fill=(150, 150, 150)) d.rectangle([9, 9, 13, 13], fill=(80, 80, 80)) d.rectangle([2, 10, 5, 13], fill=(160, 160, 160)) img.save(path, 'PNG') ``` --- ## Minimal GameTest (if required) ### `src/test/java/com/example/examplemod/tests/SimpleItemTest.java` ```java package com.example.examplemod.tests; import net.minecraft.gametest.framework.GameTestHelper; import net.minecraftforge.gametest.GameTest; import net.minecraftforge.gametest.GameTestNamespace; @GameTestNamespace("examplemod") public class SimpleItemTest { @GameTest public static void test_item_exists(GameTestHelper helper) { helper.succeed(); } } ``` > Note: This is the CORRECT API for Forge 1.21.11-61.2.0. Do NOT use `net.minecraft.gametest.framework.GameTest` or `GameTestHolder` in this version — they fail to compile here. --- ## Do NOT - Do NOT read `build.gradle`, `Config.java`, `mods.toml`, or `ExampleMod.java` repeatedly before writing. - Do NOT search `mc_java_sources` for simple item/block APIs. - Do NOT write `` citations for simple tasks. - Write the files above first, then run `gradlew build` / `run_test_gametest`, and only fix errors from logs.