A powerful networking utility for Minecraft protocol debugging, state synchronization testing, and network analysis. Built on the Architectury API for Fabric and NeoForge.
Warning
This tool is for educational and debugging purposes only. Using it to gain an unfair advantage or perform exploits on multiplayer servers is a violation of most server rules and platform terms of service. The developers do not condone cheating/duping. Use this mod at your own risk and only where you have explicit permission.
NetUtils adds a comprehensive suite of client-side debugging tools that allow you to interact with the Minecraft networking layer in ways the vanilla client cannot:
- Packet Flow Control: Intercept, delay, or completely toggle outgoing packets to test server-side response times and handling.
- Inventory State Manipulation: Experiment with client-server desynchronization (e.g., closing screens locally without notifying the server) to test state handling logic.
- Detailed Data Extraction: View internal menu information (Sync IDs, Class names), list villager trades with internal IDs, and inspect GUI slot metadata.
- Resource Pack Management: Bypass or force-deny server-requested resource packs for testing environment isolation.
- Enhanced Client-Side Commands: A custom command system (using the
^prefix) for low-level interaction, including raw packet sending and loop execution.
- Mod & Plugin Development: If you are developing a mod or server plugin that relies on complex inventory or networking logic, NetUtils is an invaluable tool for stress-testing your code against "illegal" or unexpected client states.
- Protocol Education: Perfect for developers and researchers who want to understand the Minecraft networking protocol by observing and manipulating packets in real-time.
- Network Resilience Testing: Use the desynchronization and packet delay features to verify that your server's anti-cheat or state-recovery systems are robust.
- Clean & Transparent: This project is maintained as a safe, open-source alternative to historical versions of similar utilities (like UIUtils v1.0.2) which were known to contain security vulnerabilities.
- Multiplayer Usage: Using this on public servers will likely result in a permanent ban. It is intended for use in private development environments.
- Compatibility: Requires Minecraft 1.21.11 and the Architectury API.
- Packet Control: Delay or toggle outgoing packets.
- Synchronization: Simulate client-server desynchronization for state handling tests.
- Inventory Control: Close inventory screens without sending packets to the server.
- Resource Pack Control: Bypass or force-deny server resource packs.
Press V to restore the last closed screen.
All commands use the ^ prefix and can be typed in regular chat or the custom chat input field.
^help- Show all commands^toggle- Enable/disable mod features^menuinfo- Display GUI info (class, slots, sync ID)^trades- List villager trades with IDs^trade <id>- Automatically select and execute a trade^click <slot> [button] [type]- Click a specific inventory slot^loop <n> <command>- Repeat a commandntimes^desync- Synchronize/Desynchronize inventory state^clear- Clear the chat log^packets- List available packet types for^rawsend^rawsend <times> <packet> [args]- Force send raw packets to the server^save/^load- Save or restore the current screen state
Run the following command to build for both Fabric and NeoForge:
./gradlew collectJarsThe output jars will be in build/libs/.
This project is licensed under the MIT License - see the LICENSE file for details.