Fabric Package Logger

A deep packet logging mod for Minecraft Fabric that captures all network traffic (S2C and C2S) with full NBT/Component data.

Use Cases

• Mod Development: Debug network communication between client and server
• Container Inspection: View exact contents of inventories with full NBT/Component data and copying them
• Reverse Engineering: Analyze server-side mechanics and packet structures
• Anti-Cheat Analysis: Understand what data the server sends and receives
• Learning: Understand how Minecraft's network protocol works

Usage

Keybind

Press F6 to open the config screen.

Packet Selection

Use the dual-list selector to choose which packets to log:

• S2C (Server → Client): Incoming packets like inventory updates, entity spawns, etc.
• C2S (Client → Server): Outgoing packets like clicks, movements, etc.

Log Modes

• Chat: Display packets in the game chat (truncated for readability)
• File: Save packets to log files with full data

Log Files

Logs are saved to:

MINECRAFT_FOLDER/config/package-logger/packets_2026-01-04_15-30-45_servername.log

A new log file is created when:

• Joining a world/server
• Re-enabling logging after it was disabled

Example Output

[12:34:56.789] [S2C] InventoryS2CPacket {syncId:2,revision:1,id:"minecraft:generic_9x3",components:{"minecraft:container":[{item:{id:"minecraft:diamond_sword",count:1,components:{"minecraft:enchantments":{levels:{"minecraft:sharpness":5}}}},slot:0}]}}

Available Packets

S2C Packets (Server → Client)

C2S Packets (Client → Server)

License

MIT

Credits

• Fabric API Team
• Minecraft Modding Community