TrinketInventory
A lightweight, stack-aware trinket GUI for Paper/Spigot 1.21+. Clean attribute handling with modern registry APIs, safe removal, and simple configuration.

What it does

• Adds a personal “trinket” inventory GUI that players can open (default command: /myinv).
  
  
• Items placed in unlocked slots grant attribute bonuses.
  
  
• Stack size in a single slot scales the bonus (up to the item’s max-stack-size), then global caps apply.
  
  
• Saves each player’s trinket inventory to disk and reapplies on join/respawn/world change (configurable).

Highlights

• Custom GUI: configurable title, rows, and locked slots with filler item.
  
  
• Whitelist and categories: allow only specific items, or enable category matching by ID prefix/name/lore.
  
  
• Modern attributes: uses the registry and keyed AttributeModifiers (no deprecated enum/UUID APIs).
  
  
• Safe and deterministic: per-player modifier keys and a re-entrancy guard to avoid duplicate application.
  
  
• Balance controls: per-attribute caps (e.g., armor, max_health, movement_speed, luck).
  
  
• Duplicate control: optionally disallow multiple slots with the same item ID (stack count in a single slot still counts).

How it works

1. Player opens the trinket GUI and places allowed items into unlocked slots.
   
   
2. Each allowed item contributes its configured modifiers. If the item is stacked, its effect is multiplied by the stack amount (capped by the item’s max-stack-size).
   
   
3. Totals are capped by your global attribute caps.
   
   
4. Modifiers are applied immediately on equip/move and on the events you enable in config.

Commands

• /myinv — Open your trinket inventory (name is configurable).

Permissions

• trinketinventory.open — Open the GUI
  
  
• trinketinventory.use — Interact with the GUI
  
  
• trinketinventory.bypass.duplicate — Allow duplicate item IDs in multiple slots
  
  
• trinketinventory.bypass.whitelist — Ignore whitelist restrictions
  
  
• trinketinventory.bypass.caps — Ignore attribute caps

Safety and enforcement

• Locked slots are enforced for clicks, drags, shift-moves, and hotbar swaps.
  
  
• Whitelist is enforced on all move types (cursor place, swap with cursor, shift-click into GUI, hotbar swap, drag into top inventory).

Modifiers are removed and re-applied atomically to prevent “Modifier already applied” errors.


FAQ
Q: Do stack sizes matter?
A: Yes. A single slot’s stack amount scales the bonus up to the item’s configured max-stack-size, then global caps may limit further gains.

Q: Why doesn’t speed/armor go past a value?
A: You likely hit the configured cap. Adjust stacking.attribute-caps or grant the bypass permission.

Q: Can I disable vanilla or ItemsAdder items?
A: Yes—see the “rules” section in the config.

Notes

• Attribute keys in the config should be plain (e.g., max_health, armor, movement_speed).
  
  
• The plugin normalizes and validates attributes against the server’s registry to avoid typos.

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