Fabric Packet Logger

Minecraft 版本： 1.21.9

平台： fabric

标签： game-mechanics technology utility

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)

Click to expand (108 packets) - AdvancementUpdateS2CPacket - BlockBreakingProgressS2CPacket - BlockEntityUpdateS2CPacket - BlockEventS2CPacket - BlockUpdateS2CPacket - BossBarS2CPacket - BundleS2CPacket - ChangeUnlockedRecipesS2CPacket - ChatMessageS2CPacket - ChatSuggestionsS2CPacket - ChunkBiomeDataS2CPacket - ChunkDataS2CPacket - ChunkDeltaUpdateS2CPacket - ChunkLoadDistanceS2CPacket - ChunkRenderDistanceCenterS2CPacket - ChunkSentS2CPacket - ClearTitleS2CPacket - CloseScreenS2CPacket - CommandSuggestionsS2CPacket - CommandTreeS2CPacket - CooldownUpdateS2CPacket - CraftFailedResponseS2CPacket - DamageTiltS2CPacket - DeathMessageS2CPacket - DebugSampleS2CPacket - DifficultyS2CPacket - EndCombatS2CPacket - EnterCombatS2CPacket - EnterReconfigurationS2CPacket - EntitiesDestroyS2CPacket - EntityAnimationS2CPacket - EntityAttachS2CPacket - EntityAttributesS2CPacket - EntityDamageS2CPacket - EntityEquipmentUpdateS2CPacket - EntityPassengersSetS2CPacket - EntityPositionS2CPacket - EntityS2CPacket - EntitySetHeadYawS2CPacket - EntitySpawnS2CPacket - EntityStatusEffectS2CPacket - EntityStatusS2CPacket - EntityTrackerUpdateS2CPacket - EntityVelocityUpdateS2CPacket - ExperienceBarUpdateS2CPacket - ExperienceOrbSpawnS2CPacket - ExplosionS2CPacket - GameJoinS2CPacket - GameMessageS2CPacket - GameStateChangeS2CPacket - HealthUpdateS2CPacket - InventoryS2CPacket - ItemPickupAnimationS2CPacket - LightUpdateS2CPacket - LookAtS2CPacket - MapUpdateS2CPacket - NbtQueryResponseS2CPacket - OpenHorseScreenS2CPacket - OpenScreenS2CPacket - OpenWrittenBookS2CPacket - OverlayMessageS2CPacket - ParticleS2CPacket - PlayerAbilitiesS2CPacket - PlayerActionResponseS2CPacket - PlayerListHeaderS2CPacket - PlayerListS2CPacket - PlayerPositionLookS2CPacket - PlayerRemoveS2CPacket - PlayerRespawnS2CPacket - PlayerSpawnPositionS2CPacket - PlaySoundFromEntityS2CPacket - PlaySoundS2CPacket - ProfilelessChatMessageS2CPacket - ProjectilePowerS2CPacket - RemoveEntityStatusEffectS2CPacket - RemoveMessageS2CPacket - ScoreboardDisplayS2CPacket - ScoreboardObjectiveUpdateS2CPacket - ScoreboardScoreResetS2CPacket - ScoreboardScoreUpdateS2CPacket - ScreenHandlerPropertyUpdateS2CPacket - ScreenHandlerSlotUpdateS2CPacket - SelectAdvancementTabS2CPacket - ServerMetadataS2CPacket - SetCameraEntityS2CPacket - SetTradeOffersS2CPacket - SignEditorOpenS2CPacket - SimulationDistanceS2CPacket - StartChunkSendS2CPacket - StatisticsS2CPacket - StopSoundS2CPacket - SubtitleS2CPacket - SynchronizeRecipesS2CPacket - TeamS2CPacket - TickStepS2CPacket - TitleFadeS2CPacket - TitleS2CPacket - UnloadChunkS2CPacket - UpdateSelectedSlotS2CPacket - UpdateTickRateS2CPacket - VehicleMoveS2CPacket - WorldBorderCenterChangedS2CPacket - WorldBorderInitializeS2CPacket - WorldBorderInterpolateSizeS2CPacket - WorldBorderSizeChangedS2CPacket - WorldBorderWarningBlocksChangedS2CPacket - WorldBorderWarningTimeChangedS2CPacket - WorldEventS2CPacket - WorldTimeUpdateS2CPacket

C2S Packets (Client → Server)

Click to expand (47 packets) - AcknowledgeChunksC2SPacket - AcknowledgeReconfigurationC2SPacket - AdvancementTabC2SPacket - BoatPaddleStateC2SPacket - BookUpdateC2SPacket - ButtonClickC2SPacket - ChatCommandSignedC2SPacket - ChatMessageC2SPacket - ClickSlotC2SPacket - ClientCommandC2SPacket - ClientStatusC2SPacket - CloseHandledScreenC2SPacket - CommandExecutionC2SPacket - CraftRequestC2SPacket - CreativeInventoryActionC2SPacket - DebugSampleSubscriptionC2SPacket - HandSwingC2SPacket - JigsawGeneratingC2SPacket - MessageAcknowledgmentC2SPacket - PickFromInventoryC2SPacket - PlayerActionC2SPacket - PlayerInputC2SPacket - PlayerInteractBlockC2SPacket - PlayerInteractEntityC2SPacket - PlayerInteractItemC2SPacket - PlayerMoveC2SPacket - PlayerSessionC2SPacket - QueryBlockNbtC2SPacket - QueryEntityNbtC2SPacket - RecipeBookDataC2SPacket - RecipeCategoryOptionsC2SPacket - RenameItemC2SPacket - RequestCommandCompletionsC2SPacket - SelectMerchantTradeC2SPacket - SlotChangedStateC2SPacket - SpectatorTeleportC2SPacket - TeleportConfirmC2SPacket - UpdateBeaconC2SPacket - UpdateCommandBlockC2SPacket - UpdateCommandBlockMinecartC2SPacket - UpdateDifficultyC2SPacket - UpdateDifficultyLockC2SPacket - UpdateJigsawC2SPacket - UpdatePlayerAbilitiesC2SPacket - UpdateSelectedSlotC2SPacket - UpdateSignC2SPacket - UpdateStructureBlockC2SPacket - VehicleMoveC2SPacket

License

MIT

Credits

• Fabric API Team
• Minecraft Modding Community