Expendable Backpacks

A comprehensive backpack system featuring eight progressive tiers, upgradeable storage, placeable backpack blocks, and unique Enderpack shared inventory functionality.

---

✨ Features

• Eight Progressive Tiers - From basic Dirt Backpack (9 slots) to premium Netherite Backpack (54 slots)
• Placeable Backpacks - Place backpacks as blocks in the world using Shift + Right-click
• Enderpack System - Unique shared storage across multiple Enderpacks using UUID-based identification
• Starter Backpack Configuration - Give new players a Leather Backpack on first join
• Stackable Upgrades - Upgrade your backpacks by surrounding them with materials while preserving all contents
• Inception Protection - Smart system prevents nesting backpacks within other backpacks
• Interactive GUI Guide - In-game visual guide showing all crafting recipes and upgrade paths
• Custom Textures - Beautiful player head textures for each tier with color-coded names
• Persistent Storage - All backpack contents automatically saved with UUID tracking
• Enderpack Cloning - Create multiple access points to the same shared inventory
• Full Protection - Placed backpacks are protected from explosions, pistons, fire, and lava
• Performance Optimized - Efficient inventory caching and asynchronous data saving
• Tab Completion - Full tab completion support for all commands and UUIDs

---

🎒 Backpack Tiers

Tier	Storage	Upgrade Material
Dirt Backpack	9 slots (1 row)	Surround with Dirt
Leather Backpack	9 slots (1 row)	Starting tier
Copper Backpack	18 slots (2 rows)	8x Copper Ingot
Iron Backpack	27 slots (3 rows)	8x Iron Ingot
Gold Backpack	36 slots (4 rows)	8x Gold Ingot
Diamond Backpack	45 slots (5 rows)	8x Diamond
Netherite Backpack	54 slots (6 rows)	Smithing Table
Enderpack	27 slots (3 rows)	Shared Storage

---

📦 Placeable Backpacks

Backpacks can now be placed in the world as decorative blocks that retain full functionality!

How It Works

• Place: Hold a backpack and Shift + Right-click on any surface
• Open: Right-click the placed backpack to access its inventory
• Break: Mine the block to retrieve your backpack with all contents intact
• Protection: Placed backpacks are fully protected from:
  • Explosions (Creeper, TNT, etc.)
  • Pistons (push/pull)
  • Fire and lava damage
  • Block explosions (Beds, Respawn Anchors)

Use Cases

• Storage Rooms - Create organized storage areas with visible backpack tiers
• Base Decoration - Display your collection of high-tier backpacks
• Quick Access Points - Place backpacks at strategic locations around your base
• Team Storage - Place shared Enderpacks in communal areas
• Shops & Trade - Create backpack displays in marketplace builds

Important Notes

• Placed backpacks retain their UUID - items stay exactly where they are
• Breaking and replacing a backpack doesn't affect its contents
• Enderpacks work the same when placed - all copies share the same inventory
• You can still open backpacks in your hand with a normal right-click

---

🌌 Enderpack - The Special One

The Enderpack provides unique functionality not found in other tiers:

• Shared Storage - All Enderpacks with the same UUID access identical inventory
• Cloneable - Craft 1 Enderpack + 1 Ender Pearl = 2 Enderpacks with matching UUID
• Multiple Access Points - Keep one in your inventory, one at your base, share with teammates
• Works When Placed - Place Enderpacks as blocks and they still share the same inventory
• Perfect for Teams - Coordinate shared storage across multiple players
• Cross-Location Access - Access the same inventory from anywhere

Example Use Case

1. Craft an Enderpack
2. Clone it by combining with an Ender Pearl (yields 2 Enderpacks, same UUID)
3. Keep one in your inventory for on-the-go access
4. Place one as a block at your base for easy access
5. Give one to a teammate
6. All three access the same 27-slot shared storage - even the placed one!

---

⚙️ Configuration

The plugin includes a configuration file at plugins/ExpendableBackpacks/config.yml for server customization.

Starter Backpack Feature

Give new players a Leather Backpack automatically when they first join your server:

# Give a Leather Backpack to players when they first join the server
# Default: false
give-backpack-on-first-join: false

# Message sent to players when they receive their starter backpack
# Use & for color codes (e.g., &a for green, &6 for gold)
# Set to empty string ("") to disable the message
starter-backpack-message: "&7Welcome! You've been given a &7Leather Backpack &7to get started. Right-click to open!"

Features:

• Only triggers for players joining for the first time
• Automatically adds backpack to inventory
• Drops at player location if inventory is full
• Customizable welcome message with color code support
• Disabled by default - enable it in your config

---

🚀 Installation & Compatibility

1. Download the latest plugin JAR file
2. Place it in your server's /plugins/ directory
3. Restart your server or use a plugin loader
4. Use /backpack to access the in-game guide
5. Configure starter backpack in plugins/ExpendableBackpacks/config.yml (optional)

Requirements

• Server Software: Paper, Spigot, Purpur, or Folia
• Minecraft Version: 1.21 or higher
• Java Version: 21 or higher

---

🔧 Commands & Permissions

Commands

All commands support the /bp alias for quick access.

Command	Description	Permission
/backpack	Open interactive guide GUI	backpack.use
/backpack help	Display help information	backpack.use
/backpack give <player> <tier>	Give a backpack to a player	backpack.give
/backpack open <uuid>	Open a backpack by UUID	backpack.openOthers
/backpack clear <uuid>	Clear backpack contents	backpack.clear
/backpack clone <uuid>	Create an Enderpack clone	backpack.clone

Permissions

Permission	Description	Default
backpack.use	Use backpack command and open own backpacks	Everyone
backpack.give	Give backpacks to players	OP
backpack.openOthers	Open any backpack by UUID	OP
backpack.clear	Clear backpack contents	OP
backpack.clone	Clone Enderpacks	OP
backpack.admin	All admin permissions	OP

---

🔨 Crafting Recipes

Leather Backpack (Starting Point)

L S L
L C L
L L L

• L = Leather, S = String, C = Chest

Enderpack (Special Recipe)

E P E
P C P
E I E

• E = Ender Eye, P = Ender Pearl, C = Chest, I = Iron Block

Upgrades

Surround your backpack with 8x upgrade material:

• Leather → Copper: 8x Copper Ingot
• Copper → Iron: 8x Iron Ingot
• Iron → Gold: 8x Gold Ingot
• Gold → Diamond: 8x Diamond
• Diamond → Netherite: Smithing Table (Netherite Upgrade Template + Diamond Backpack + Netherite Ingot)

Note: All upgrades preserve your items and UUID!

---

💾 Technical Details

Data Storage

• Backpacks stored in plugins/ExpendableBackpacks/backpacks.yml
• UUID-based identification for each backpack instance
• Placed backpacks store UUID in block PersistentDataContainer
• Automatic inventory serialization
• Data persists across server restarts

Performance

• Efficient inventory caching system
• Asynchronous data saving
• Optimized block interaction handling
• Optimized for large-scale servers
• Minimal server resource usage

Placed Backpack Technical Details

• Placed as Player Head blocks with custom textures
• UUID and tier data stored in block NBT (PersistentDataContainer)
• Same NamespacedKeys as items for consistency
• Full event handling for comprehensive protection

---

🆘 Support & Links

• Issues & Bug Reports: GitHub Issues
• Source Code: GitHub Repository
• Documentation: Full README

---

📜 License

See the LICENSE file for details.

---

Developed with care for the Minecraft server community.