Ultimate Multiplayer Inventory Framework (UMI)

Build Multiplayer Inventory Systems — Fast

The Ultimate Multiplayer Inventory Framework (UMI) is a production-ready, modular inventory solution built for Unreal Engine 5. Stop wrestling with replication logic and start shipping your game.

What's Included

• Replicated Inventory — Fully networked inventory system with authoritative server logic
• Equipment System — Modular equip/unequip with slot management
• Containers & Loot — Chest, drop, and loot table support out of the box
• Interaction Support — Built-in interaction framework for pickups and world items
• Crafting-Ready Architecture — Extensible data structures designed for crafting systems

Who Is This For?

Indie developers and studios building multiplayer games in UE5 who need a reliable, scalable inventory foundation without building from scratch.

⚔️ Multiplayer First

• Fully replicated inventory systems

• Server-authoritative item handling

• Dedicated server support

• Multiplayer-safe item instances

• Optimized replication workflows

• LAN / Listen Server / Steam ready

🛠️ Blueprint Friendly — Powered by C++

• Blueprint-first workflows

• No C++ knowledge required

• Blueprint events & interfaces

• Data Asset driven systems

• Gameplay Tag integration

• Optional C++ extensibility

💾 Production-Grade Persistence Framework

UMI includes a scalable multiplayer persistence framework designed for long-term projects and dedicated server environments. The system supports asynchronous save workflows, stable GUID-based object persistence, unique item instance serialization, modular save buckets, autosave support, and plugin-friendly save integration — allowing inventories, equipment, containers, and world data to persist independently without relying on monolithic save files.

🎒 Inventory & Equipment

• Slot-based and Jigsaw style inventory

• Equipment slots

• Hotbar support

• Drag & drop functionality

• Stackable items

• Weight & encumbrance

• Containers & storage

• Loot bag support

• Durability & decay systems

🤝 Interaction Framework

• Press interactions

• Hold interactions

• Multi-press support

• Multiple interaction options

• Input-aware prompts

• Multiplayer-safe interactions

🔧 Developer Features

• Modular plugin architecture

• Blueprint & C++ support

• Interface-driven design

• Enhanced Input support

• Gameplay Ability System hooks

• Common UI friendly workflows

• Designed for integration into existing projects

📚 Documentation & Support

Includes:

• Written documentation

• Example implementations

• Blueprint example project

• Integration guidance

• Ongoing updates and improvements