Packet Spy

Security Disclosure

Important Security Notice

PacketSpy intercepts and displays real-time Minecraft network packets (both outgoing and incoming) via a local web interface at http://localhost:8887.

• The built-in web server is strictly bound to localhost for single-machine use only.
• Displayed packet data may contain sensitive information, including chat messages, player coordinates, inventory contents, custom mod data, or other gameplay details.
• Users should take precautions:
  • Avoid modifying the server configuration to expose the port externally.
  • Prevent unauthorized access to the device, as anyone with local access could view the interface.
  • Be mindful when sharing screenshots, recordings, or logs, as they may reveal private information.
• This tool is intended solely for personal debugging and development. Use it responsibly, respecting server rules, privacy norms, and applicable laws.

No remote vulnerabilities are known in the current version, but exercise standard caution with any network inspection tool.

PacketSpy

PacketSpy is a lightweight, client-side network debugging tool for Minecraft Fabric (supports versions 1.21–1.21.3). It provides real-time inspection of packets exchanged between the client and server, making it ideal for mod developers and advanced players troubleshooting network issues.

Unlike traditional logging that clutters the console or chat, PacketSpy runs a local web server (powered by Java-WebSocket) to stream packet data to a clean, browser-based dashboard at http://localhost:8887.

Key Features

• Real-Time Monitoring: Instantly view packet names, directions (TX/RX), and timestamps as they happen.
• External Web Dashboard: Keeps the in-game experience uncluttered—monitor everything in a separate browser tab.
• Intelligent Filtering: Toggle filters to suppress high-volume "noise" packets (e.g., move_player_pos and move_player_rot), highlighting important events like custom mod packets or rare interactions.

Why Use PacketSpy?

For Players & Power Users

• Eliminate chat/log spam from packet debugging.
• Clear, readable packet list with essential details.
• Automatically filter out mundane movement updates to focus on meaningful traffic.
• Perfect for diagnosing lag, mod conflicts, or server-side anomalies.

For Mod Developers

• Observe custom packets in real time to quickly identify and fix issues.
• Keep the game window free of debug output.
• Prioritize relevant packets with built-in filters.
• Minimal overhead—lightweight and fully compatible with Fabric Loader.

PacketSpy turns complex network debugging into a straightforward, efficient process.

Current Version: 2.0
Built With: Gradle
Logo: AI-generated (via ChatGPT)

PacketSpy is a client-side Fabric mod for viewing the network packets your Minecraft client sends and receives in real time.

Press F12 (can be rebound in settings) in-game to open the local web interface. From there you can search and filter packets, inspect their fields as JSON, sort packet traffic, mute noisy packet types, and export what you're looking at.

It works in both singleplayer and multiplayer and does not need to be installed on the server.

Features

• Live incoming and outgoing packet viewer
• Search and filter by packet type, direction and category
• View packet contents as readable JSON
• Mute packet types you don't care about
• Packet grouping and traffic visualization
• Dark and light themes
• Local web interface
• Optional LAN access if you want to view it from another device

PacketSpy supports Minecraft 1.21–1.21.11 and 26.1–26.3 using Fabric. Make sure to download the jar that matches your Minecraft version.

The web interface runs locally on your computer and LAN access is disabled by default.