Custom Items

What you are building

Step-by-step

1. Create the pack shellMake pack.mcmeta, data/<namespace>/ and load/tick function tags.
2. Create the item definitionAdd one JSON file under dai_items. Give it a stable namespaced ID and keep that ID unchanged across releases.
3. Choose a vanilla carrierPick an item that behaves acceptably even when no companion resource pack is installed. This is especially important for stackable addons.
4. Add server-visible identityUse stable custom data/components so functions and reactions can distinguish your item from the vanilla carrier.
5. Give it from a functionCreate function/item/give_*.mcfunction so the authoritative server constructs the exact item stack.
6. Add interaction logicRoute right-click, attack, inventory or reaction events to server functions; never make the visual model the source of gameplay truth.
7. Add optional presentationA resource pack may target the stable item identity for a custom model while the datapack remains functional without it.
8. Test the fallbackDisable the resource pack and verify the item still has usable vanilla visuals and all mechanics still work.

Definition of done

• The feature still works after save/reload.
• Server state is authoritative; presentation mirrors it.
• Invalid input cannot duplicate rewards or bypass costs.
• Two players can use the system without sharing unintended temporary state.
• Any optional resource pack can be disabled without breaking datapack logic.

Next integration

Once this feature works alone, connect it to a complete loop instead of adding more isolated content. Use the complete-game tracks to see where it belongs in ACMS, Space Between Blocks, MineTrigger or Hollow Spiral.