protocol

KnC Protocol Documentation

Complete network protocol documentation for Kart n' Crazy (KnC)

---

Main Index

Document	Description
PROTOCOL_OVERVIEW.md	Complete protocol overview
STRUCTURES.md	Detailed C++ structures (PlayerInfo, VehicleData, etc.)
MESSAGES.md	Message types and formats

---

Packets by Category (179 files)

auth/ - Authentication & Session (17 packets)

Connection management, authentication, heartbeat

Opcode	Name	Description
0x01	LOGIN_RESPONSE	Login response
0x02	DISPLAY_MESSAGE	Display message
0x03	CHARACTER_CREATION_TRIGGER	Character creation trigger
0x04	REGISTRATION_RESPONSE	Registration response
0x07	SESSION_INFO	Session info
0x0A	CONNECTION_OK	Connection OK
0x0B	ACK	Acknowledgment
0x0C	DATA_PAIRS	Key/value pairs
0x0D	FLAG_SET	Flag configuration
0x12	SHOW_LOBBY	Show lobby
0x8E	NO_HANDLER	No handler
0xA6	HEARTBEAT	Heartbeat
0xA7	SESSION_CONFIRM	Session confirm
0xAA	PLAYER_PREVIEW	Player preview

See all auth/ packets

---

chat/ - Chat & Messaging (9 packets)

Messages, whispers, players

Opcode	Name	Description
0x116	PLAYER_NAME	Player name
0x117	PLAYER_REMOVE	Remove player
0x2A	WHISPER_ENABLE	Enable whisper
0x2B	WHISPER_DISABLE	Disable whisper
0x2D	CHAT_MESSAGE	Chat message
0x2E	PLAYER_LEFT	Player left
0x6C	PLAYER_MESSAGE	Player message
0x6E	MESSAGE_DISPLAY	Display message

See all chat/ packets

---

client/ - Client → Server (9 packets)

Packets sent by client

Opcode	Name	Description
0x07	CLIENT_AUTH	Client authentication
0x19	SERVER_QUERY	Server query
0x2C	STATE_CHANGE	State change
0x32	UNKNOWN	Unknown
0x4D	REQUEST_DATA	Request data
0x73	DISCONNECT	Disconnect
0xD0	CLIENT_INFO	Client info
0xFA	FULL_STATE	Full state

See all client/ packets

---

game/ - Game & Racing (71 packets)

Racing, items, positions, results

Position & Movement

• 0x31 POSITION
• 0x100 POSITION_REMOVE
• 0x101 POSITION_UPDATE_A
• 0x102 POSITION_UPDATE_B
• 0xFC POSITION_LIST
• 0xFE POSITION_ADD

Race State

• 0x14 GAME_MODE
• 0x30 ROOM_STATE
• 0x33 GAME_STATE
• 0x34 READY_FLAG
• 0x3B COUNTDOWN
• 0x3C RACE_END
• 0x40 START_RACE

Lap & Track

• 0x36 LAP_INFO
• 0xF3 TRACK_DATA
• 0xF4 CHECKPOINT_LIST
• 0xF6 RACE_INIT
• 0xF7 RACE_WAYPOINTS
• 0xF9 CHECKPOINT_ADD
• 0xFB LAP_DATA

Items

• 0x37 ITEM_USE
• 0x38 ITEM_HIT
• 0x45 ITEM_USAGE
• 0x10D ITEM_BLOCK
• 0x10F ITEM_LIST_UPDATE
• 0x115 ITEM_VALUE

Results

• 0x35 SCORE
• 0x39 FINISH
• 0x3A RESULTS

See all 71 game/ packets

---

inventory/ - Inventory & Items (32 packets)

Inventory, vehicles, accessories

Item Management

• 0x70 INVENTORY_UPDATE
• 0x78 ITEM_LIST
• 0x79 ITEM_LIST_B
• 0x81 RESULT_CODE
• 0x84 ITEM_FLAG
• 0x85 ITEM_UPDATE_B
• 0x8C EQUIP_ITEM

Shop Data

• 0x82 SHOP_DATA
• 0x83 SHOP_DATA_ALT

Slot Management

• 0x88 SLOT_LIST
• 0x8A SLOT_ENTRY

Add Items

• 0x98 GIFT
• 0x9D ADD_VEHICLE
• 0x9E ADD_ITEM
• 0x9F ADD_ACCESSORY

See all inventory/ packets

---

room/ - Room Management (18 packets)

Game room management

Opcode	Name	Description
0x21	ROOM_FULL / ROOM_PLAYER_INFO	Room/player info
0x22	LEAVE_ROOM	Leave room
0x23	PLAYER_UPDATE	Player update
0x25	ROOM_STRING	Room string
0x27	ROOM_INFO_ALT	Room info alt
0x28	ENTITY_DATA	Entity data
0x30	ROOM_STATE	Room state
0x3E	PLAYER_JOIN	Player join
0x3F	ROOM_INFO	Room info
0x62	TUTORIAL_FAIL	Tutorial fail
0x63	CREATE_ROOM	Create room
0xBF	ROOM_LIST	Room list
0xC0	ROOM_DETAIL	Room detail
0xC1	ROOM_LIST_B	Room list B
0xC2	ROOM_STATUS	Room status
0xC3	ROOM_DATA	Room data
0xC5	ROOM_INFO_EXT	Room info extended

See all room/ packets

---

shop/ - Shop (8 packets)

Game shop

Opcode	Name	Description
0x6F	SHOP_ACTION	Shop action
0x72	DATA_BLOCK	Data block
0x73	SLOT_UPDATE	Slot update
0x74	UNKNOWN	Unknown

See all shop/ packets

---

system/ - System (9 packets)

System packets

Opcode	Name	Description
0xAA	PLAYER_DATA	Player data
0xB5	DUAL_PLAYER_INFO	Dual player info
0xCD	AUDIO_CONTROL	Audio control
0xEE	ENTITY_UPDATE	Entity update
0xF0	ENTITY_REMOVE	Entity remove
0xF1	ENTITY_DATA	Entity data

See all system/ packets

---

ui/ - User Interface (19 packets)

UI transitions, screen states

Opcode	Name	Description
0x10A	TRIGGER_UI_18	Trigger UI 18
0x10E	TRIGGER_UI_19	Trigger UI 19
0x13	PLAYER_ROOM_DATA	Player/room data
0x16	UI_STATE_14	UI state 14
0x18	STRING_PARAMS	String params
0x62	TUTORIAL_FAIL	Tutorial fail
0xB6	DISPLAY_TEXT	Display text

See all ui/ packets

---

Typical Flow

sequenceDiagram
    participant C as Client
    participant L as Login Server (50017)
    participant G as Game Server (50018)
    
    C->>L: 0xD0 CLIENT_INFO
    L->>C: 0x0A CONNECTION_OK
    C->>L: 0x07 CLIENT_AUTH
    L->>C: 0x01 LOGIN_RESPONSE
    L->>C: 0x12 SHOW_LOBBY
    
    loop Heartbeat
        C->>L: 0xA6 HEARTBEAT (every 30s)
    end
    
    C->>G: Connect (TCP 50018)
    G->>C: 0x30 ROOM_STATE
    
    loop Game
        C->>G: 0x31 POSITION
        G->>C: 0x101 POSITION_UPDATE_A
        G->>C: 0x36 LAP_INFO
    end

Loading

---

How to Use This Documentation

1. Find a Packet by Opcode

Search for the opcode (e.g. 0x31) in the tables above, then click on the category link.

2. Understand the Global Protocol

Read PROTOCOL_OVERVIEW.md for the complete overview.

3. Implement a Handler

1. Find the packet in the appropriate category
2. Read the structure in the .md file
3. Reference STRUCTURES.md for complex types
4. See ../client-clone/05_network_protocol.md for implementation

4. Debug a Packet

Use tools/packet_inspector to capture and analyze packets in real-time.

---

Tools

Tool	Description
packet_inspector	Sniff/decode network packets
network_decrypt	Decrypt Network2.ini

---

Related Documentation

• Client Architecture
• Network Protocol Implementation
• File Formats
• IDA Reverse Engineering Guide

---

Documentation Status

Category	Packets	Documented	Status
auth	17	17	✅ 100%
chat	9	9	✅ 100%
client	9	9	✅ 100%
game	71	71	✅ 100%
inventory	32	32	✅ 100%
room	18	18	✅ 100%
shop	8	8	✅ 100%
system	9	9	✅ 100%
ui	19	19	✅ 100%
TOTAL	192	192	✅ 100%

---

Last Updated: December 2025
Method: IDA Pro + Ghidra + DevClient testing