/Dupe Plugin

DupePlugin
Simple item duplication with a configurable blacklist.

Features
/dupe [amount] — Duplicate the item in your hand up to 64 times in one command
Inventory-safe — Checks if there's enough space before duplicating; never drops items on the ground accidentally
Configurable blacklist — Prevent specific items from being duped via config.yml (no restart needed)
Automatic lore tagging — Blacklisted items automatically get a red ✗ Cannot be Duped tooltip in their lore when picked up, crafted, or moved in inventory
/dupe reload — Reload the config live without restarting the server
Blacklist
Out of the box, the following items cannot be duplicated:

Category Items
Netherite Tools Sword, Pickaxe, Axe, Shovel, Hoe
Netherite Armor Helmet, Chestplate, Leggings, Boots
Netherite Materials Ingot, Scrap, Block, Upgrade Smithing Template
Special Dragon Egg, Nether Star, Beacon
You can fully customize this list in plugins/DupePlugin/config.yml.

Commands
Command Description Permission Default
/dupe Duplicate held item once dupeplugin.dupe OP
/dupe Duplicate held item N times (max 64) dupeplugin.dupe OP
/dupe reload Reload config without restart dupeplugin.admin OP
Configuration
After first launch, edit plugins/DupePlugin/config.yml:

List of materials that CANNOT be duplicated.

Use Minecraft material names (uppercase, underscores).

Full list: https://jd.papermc.io/paper/1.21/org/bukkit/Material.html
blacklisted-materials:

=== Netherite ===

• NETHERITE_SWORD
• NETHERITE_PICKAXE
• NETHERITE_AXE
• NETHERITE_SHOVEL
• NETHERITE_HOE
• NETHERITE_HELMET
• NETHERITE_CHESTPLATE
• NETHERITE_LEGGINGS
• NETHERITE_BOOTS
• NETHERITE_BLOCK
• NETHERITE_INGOT
• NETHERITE_SCRAP
• NETHERITE_UPGRADE_SMITHING_TEMPLATE

=== Special Items ===

• DRAGON_EGG
• NETHER_STAR
• BEACON

Then run /dupe reload in-game to apply changes instantly.

Installation
Download DupePlugin-1.1.0.jar
Drop it into your server's plugins/ folder
Restart the server
Configure plugins/DupePlugin/config.yml to your liking
Compatibility
Server software: Paper 1.21.11
Java: 21+
No dependencies required