ProtocolLib Plugin (1.21.7, 1.20.1) – Powerful Minecraft Packet Editor for Developers

ProtocolLib Plugin (1.21.7, 1.20.1) is a core developer tool for Minecraft servers running Bukkit, Spigot, or Paper. It allows plugins to read, manipulate, and rewrite network packets without dealing with Minecraft’s complex reflection code manually. Developers rely on ProtocolLib to hook into the game protocol, intercept packets for customization, and create advanced plugin behavior without editing the base game or needing Forge or Fabric.

This library is used by dozens of popular plugins to handle data transmission, packet filtering, and custom rendering. While it doesn’t impact gameplay by itself, it’s essential for enabling features like disguises, anti-cheat systems, tab name changes, and more.

Features:

• Access to Minecraft’s packet system: Easily intercept and modify packets.
• Simplifies reflection and channel injection: Removes the need to write complex Java reflection manually.
• Packet wrappers: Provides ready-made objects to manipulate packets cleanly.
• Update-resilient: Uses field type and name detection for high Minecraft version compatibility.
• Custom filtering system: Lets you debug only specific packets using JavaScript-based filters.
• API for plugin developers: Integrates seamlessly with plugin logic.
• Version checking and auto-updating: Built-in tools for keeping ProtocolLib current.
• Works with minor Minecraft updates: Often compatible even with newer versions due to dynamic code handling.

Commands:

• /protocol config – Reload the configuration file.
• /protocol check – Check for new updates.
• /protocol update – Auto-download latest version (server restart required).
• /protocol timings – Toggle CPU usage tracking for each plugin.
• /protocol listeners – Show which plugins are intercepting which packets.

All of these require permission: protocol.admin

Packet Debugging Commands:

• /packet add – Start logging selected packets.
• /packet remove – Stop logging packets.
• /packet names – List packet names for given IDs.

For versions 3.0.0 and above:

• /packet add play server chat true – Log chat packets with full details.
• /packet add play server chat compare – View packet before any plugin modifies it.

JavaScript Filter System:

• Available from version 2.4.1+
• Example:

> packet add server 40 true
> filter add entity_filter 40
function(event, packet) {
    return packet.a == 1000;
}

• Enable in config with debug: true

Configuration Options:

global:
  auto updater:
    notify: true
    download: true
    delay: 43200
    last: 0
  metrics: true
  background compiler: true
  ignore version check: false

Permissions:

• protocol.admin: Grants access to all /protocol and /packet commands.

Compatibility & Use Cases:

ProtocolLib is compatible with many major plugins:

• Compatible Plugins:
  • Orebfuscator
  • TagAPI
  • DisguiseCraft
  • VanishNoPacket (v3.18.5 and earlier)
  • BkCommonLib
  • CraftBook
  • ChairsReloaded
  • Statues
  • Seasons
  • TabAPI
  • and dozens more
• Examples of use:
  • Modify packets for disguise or vanish plugins
  • Intercept chat packets for formatting or moderation
  • Bypass Minecraft client limitations with custom GUIs
  • Optimize server performance via filtered packet handling

Screenshots:

How to Install:

1. Download the latest ProtocolLib plugin JAR.
2. Place it in the /plugins directory of your Minecraft server.
3. Start your server to load the plugin.
4. (Optional) Type stop to cleanly shut down.
5. Restart server to ensure settings are active.

No additional setup is required unless other plugins depend on ProtocolLib.