Add Large Backpack Mod

A Minecraft Forge mod that adds a customizable large backpack with scrollable inventory.

🌟 Features

🎒 Large Backpack - Expandable storage with configurable rows (default: 10 rows / 90 slots)
📜 Scrollable GUI - Smooth scrollbar interface for accessing all items
⌨️ Key Binding - Press B key to quickly open your backpack
🔧 Configurable - Adjust backpack size via config file (1-20 rows)
🌐 Multilingual - Supports English and Japanese
💾 NBT Storage - Items persist in backpack data
🔄 Client-Server Sync - Smooth multiplayer experience

🛠️ Crafting Recipe

[Leather] [String]  [Leather]
[Leather] [Chest]   [Leather]
[Leather] [Leather] [Leather]

Materials:

7x Leather
1x String
1x Chest

🎮 Usage

Opening the Backpack

Right-click while holding the backpack
Press B key (configurable) with backpack in inventory
- Automatically opens the leftmost backpack (hotbar → main inventory)

Using the Backpack

Scroll using mouse wheel or drag the scrollbar
Click to pick up/place items
Shift+Click to quick-transfer items
Access up to 90 slots (default: 10 rows × 9 columns)

⚙️ Configuration

Config file location: config/addlargebackpack-common.toml

[backpack]
    # Number of rows in the backpack (1-20)
    # Default: 10
    backpackRows = 10

Change backpackRows to adjust the backpack size (1-20 rows).

⌨️ Key Bindings

Default: B key opens backpack

To change:

Options → Controls → Key Binds
Find "Large Backpack" category
Click "Open Backpack" and press desired key

🔧 Development

Build from Source

# Clone the repository
git clone https://github.com/sedielkue/AddLargeBackpack.git
cd AddLargeBackpack

# Build the mod
.\gradlew build

# Output: build/libs/addlargebackpack-1.0.jar

Run in Development

# Run client
.\gradlew runClient

# Run server
.\gradlew runServer

🔍 Technical Details

Features

Client-Server Synchronization - Scroll position synced across network
Dynamic Slot Mapping - Efficient slot indexing for scrollable inventory
NBT Storage - Items persist in backpack data
Smart Slot Restriction - Prevents placing backpack inside itself
Left-Priority Search - Keybind opens leftmost backpack first

Requirements

Minecraft: 1.20.1
Forge: 47.4.0 or higher
Java: 17 or higher

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.

👤 Credits

Developer: sedielkue
Texture: Custom backpack texture
Framework: Minecraft Forge

🐛 Support

Issues: GitHub Issues
Wiki: Documentation

📝 Changelog

Version 1.0.0 (Initial Release)

✅ Configurable large backpack (up to 20 rows / 180 slots)
✅ Scrollable GUI with smooth scrollbar
✅ Key binding support (B key, configurable)
✅ Crafting recipe (leather + string + chest)
✅ NBT item storage with persistence
✅ Client-server synchronization
✅ Left-priority backpack search
✅ English and Japanese translations
✅ Custom backpack texture

Enjoy your adventures with extra storage! 🎒✨