Your First Item

This tutorial registers two items: a minimal one-liner and a fully configured item, so you can see the range of the RegistryLib item API.

What You Will Learn

• How to register a basic Item with item()
• How to register a feature-rich ComponentItem with componentItem()
• The difference between the two builder types
• How to verify your items in-game

Minimal Example - Copper Coin

The shortest path to a working item:

public static final ItemEntry<Item> COPPER_COIN = RegistryLibTest.REGISTRYLIB
        .item("copper_coin", Item::new)
        .langCn("Copper Coin (zh_cn)")
        .lang("Copper Coin")
        .register();

That single chain:

1. item("copper_coin", Item::new) starts an ItemBuilder with the registry name copper_coin and the vanilla Item factory.
2. .langCn(...) adds a Simplified Chinese localization through the test project's custom builder.
3. .lang("Copper Coin") sets the English display name for datagen.
4. .register() submits the registration and returns an ItemEntry<Item> you can reference later.

Full Example - Magic Wand

When you need tooltips, creative tabs, tags, and attachments, use componentItem():

public static final ItemEntry<ComponentItem> MAGIC_WAND = RegistryLibTest.REGISTRYLIB
        .componentItem("magic_wand")
        .initialProperties(() -> new Item.Properties().stacksTo(1))
        .properties(Item.Properties::fireResistant)
        .lang("Magic Wand")
        .lang(ModRegistryCore.LANG_ZH_CN, "Magic Wand (zh_cn)")
        .defaultModel()
        .addDefaultTab()
        .addTab(CreativeModeTabs.TOOLS_AND_UTILITIES)
        .removeTab(CreativeModeTabs.TOOLS_AND_UTILITIES)
        .addTab(CreativeModeTabs.TOOLS_AND_UTILITIES)
        .addTag(ItemTags.DURABILITY_ENCHANTABLE)
        .addTooltip(Component.literal("A powerful magical artifact"))
        .addTooltip((collector, stack) -> {
            collector.node(new SubNode.Basic(Component.literal("Magic Wand"), 0), true, false);
            collector.node(new SubNode.Basic(
                    Component.literal("Durability: " + (stack.getMaxDamage() - stack.getDamageValue())),
                    10));
            collector.node(DETAIL_BOX, new SubNode.Basic(Component.literal("Detailed Information"), 0));
            collector.node(DETAIL_BOX, new SubNode.Basic(Component.literal("Fire resistant"), 10));
        })
        .attach(new InspectAttachment())
        .register();

Step-by-Step Breakdown

1. componentItem("magic_wand") starts an attachment-ready ItemBuilder that produces a ComponentItem.
2. .initialProperties(...) and .properties(...) show the two-layer property pattern. initialProperties sets the base, and properties applies modifications on top.
3. .lang(...) and .lang(ModRegistryCore.LANG_ZH_CN, ...) show the bilingual naming path. The first call sets the English name; the second adds another locale.
4. .defaultModel() generates a standard item model pointing at item/magic_wand.
5. .addDefaultTab(), .addTab(...), .removeTab(...) demonstrate the creative-tab APIs. You can add, remove, and re-add tabs freely; the final state is what counts.
6. .addTag(...) attaches a vanilla or modded item tag.
7. The two .addTooltip(...) calls show both overloads: one accepts a static Component, the other accepts a callback for dynamic tooltips built with the collector API.
8. .attach(...) binds an ItemAttachment implementation to the item.
9. .register() submits the registration and returns ItemEntry<ComponentItem>.

Choosing Between item() and componentItem()

	item()	componentItem()
Use when	You need a plain item without attachment-based behavior	You need modular attachments or attachment-driven tooltips
Produced type	Item or your custom subclass	ComponentItem
Supports .attach(...)	No	Yes
Supports .addTooltip(...)	Yes	Yes

important

.addTooltip(...) is available on both item() and componentItem() because it is defined on the base ItemBuilder and works for any item type. Only .attach(...) requires ComponentItem. If you call .attach(...) on a plain item(), it will throw at runtime.

Verify in Game

1. Run ./gradlew runClient.
2. Open a creative-mode world.
3. Search for your item name, such as "Copper Coin" or "Magic Wand", in the creative inventory.
4. Confirm the item appears with the correct name and tooltip.

If the item does not appear, check:

• Your registration class is loaded, either from your mod constructor or another loaded class.
• .register() is called at the end of the chain.

Related

• Your First Block registers a block with a matching item
• Register Items (How-To) gives the full reference for all item builder options