System Messages

This page describes the structure and purpose of Teeworlds 0.6 system messages.

Message ID	Name
0	Unused
1	NETMSG_INFO
2	NETMSG_MAP_CHANGE
3	NETMSG_MAP_DATA
4	NETMSG_CON_READY
5	NETMSG_SNAP
6	NETMSG_SNAPEMPTY
7	NETMSG_SNAPSINGLE
8	Unused
9	NETMSG_INPUTTIMING
10	NETMSG_RCON_AUTH_STATUS
11	NETMSG_RCON_LINE
12	Unused
13	Unused
14	NETMSG_READY
15	NETMSG_ENTERGAME
16	NETMSG_INPUT
17	NETMSG_RCON_CMD
18	NETMSG_RCON_AUTH
19	NETMSG_REQUEST_MAP_DATA
20	Unused
21	Unused
22	NETMSG_PING
23	NETMSG_PING_REPLY
24	Unused
25	NETMSG_RCON_CMD_ADD
26	NETMSG_RCON_CMD_REM

1 - NETMSG_INFO

The first message sent by the client. It gives the server the client's version and optional password.

• Vital : ✅
• Instant Sending : ✅
• Sending Path : Client -> Server

Structure:

Field	Type	Description
Version	String	The network version string used to check protocol compatibility.
Password	String	The server password, if needed. May be empty.

2 - NETMSG_MAP_CHANGE

Sent by the server when the client should switch to a different map.

• Vital : ✅
• Instant Sending : ✅
• Sending Path : Server -> Client

Structure:

Field	Type	Description
Map Name	String	The name of the map.
Map CRC	Integer	CRC32 of the complete original .map file, represented as a signed 32-bit integer.
Map Size	Integer	Total original file size in bytes.

3 - NETMSG_MAP_DATA

Sent by the server to transfer a raw chunk of the map file.

• Vital : ✅
• Instant Sending : ✅
• Sending Path : Server -> Client

Structure:

Field	Type	Description
Last	Boolean	1 if this is the final map chunk; otherwise 0. Packed as an integer.
Map CRC	Integer	The same map CRC announced in NETMSG_MAP_CHANGE.
Chunk	Integer	Zero-based index of this map chunk.
Chunk Size	Integer	Number of raw bytes in Data.
Data	Binary	Exactly Chunk Size bytes from the original .map file.

Each request receives one map chunk containing up to 896 bytes. Its file offset is Chunk * 896. Last is set to 1 when the chunk reaches the end of the file, including when the final chunk contains a full 896 bytes.

The first four fields use variable-length integer encoding. Data contains the bytes of the requested file slice. Packet-level compression is decoded before reassembling the file; zlib-compressed blocks inside the map remain part of the downloaded file.

4 - NETMSG_CON_READY

Sent by the server when the connection is ready and the client should send its start info.

• Vital : ✅
• Instant Sending : ✅
• Sending Path : Server -> Client

Structure:

Empty payload

5 - NETMSG_SNAP

This message sends one part of a snapshot delta split across multiple chunks.

• Vital : ❌
• Instant Sending : ✅
• Sending Path : Server -> Client

INFO

Snap is a complex type of chunk. You can find more information about it on Snap Structure page.

6 - NETMSG_SNAPEMPTY

This message reports that the snapshot has no changes from its baseline. The client keeps the baseline items and advances to the current tick.

• Vital : ❌
• Instant Sending : ✅
• Sending Path : Server -> Client

INFO

Snap is a complex type of chunk. You can find more information about it on Snap Structure page.

7 - NETMSG_SNAPSINGLE

This message sends a snapshot delta in a single chunk. Without a baseline, the delta contains the full item state.

• Vital : ❌
• Instant Sending : ✅
• Sending Path : Server -> Client

INFO

Snap is a complex type of chunk. You can find more information about it on Snap Structure page.

9 - NETMSG_INPUTTIMING

Sent by the server when it receives input for a newer prediction tick. It reports the time left until that tick, in milliseconds.

• Vital : ❌
• Instant Sending : ❌
• Sending Path : Server -> Client

Structure:

Field	Type	Description
Intended Tick	Integer	The game tick the client intended its input for.
Time Left	Integer	Time left before the intended tick, in milliseconds. Negative values mean the input was late.

INFO

Check the Input & Input Timing Chunks section for more information about this chunk.

10 - NETMSG_RCON_AUTH_STATUS

Sent by the server to update the client's rcon authentication and command-list state.

• Vital : ✅
• Instant Sending : ❌
• Sending Path : Server -> Client

Structure:

Field	Type	Description
Authenticated	Boolean	1 if authenticated; 0 otherwise.
Use Command List	Boolean	1 to use the server-provided rcon command list; 0 to clear and disable it.

11 - NETMSG_RCON_LINE

Sent by the server to print a line to the remote console on the client.

• Vital : ✅
• Instant Sending : ❌
• Sending Path : Server -> Client

Structure:

Field	Type	Description
Line	String	The text line to print in the client's remote console.

14 - NETMSG_READY

Sent by the client after it has loaded the map and is ready.

• Vital : ✅
• Instant Sending : ✅
• Sending Path : Client -> Server

Structure:

Empty payload

15 - NETMSG_ENTERGAME

Sent by the client to tell the server to start sending snapshots.

• Vital : ✅
• Instant Sending : ✅
• Sending Path : Client -> Server

Structure:

Empty payload

16 - NETMSG_INPUT

This message is sent by the client to the server with the player's input.

• Vital : ❌
• Instant Sending : ✅
• Sending Path : Client -> Server

Structure:

Field	Type	Description
Ack Game Tick	Integer	The last acknowledged server game tick.
Prediction Tick	Integer	The game tick the client is predicting with this input.
Input Size	Integer	Input size before integer packing: 40 bytes for the 10 player-input integers.
Input -> Direction	Integer	Direction the player is moving: -1 = left, 0 = neutral, 1 = right.
Input -> Target X	Integer	Horizontal aim offset relative to the character.
Input -> Target Y	Integer	Vertical aim offset relative to the character.
Input -> Jump	Integer	Jump input state.
Input -> Fire	Integer	Fire input state.
Input -> Hook	Integer	Hook input state.
Input -> PlayerFlags	Integer	Player flags for this input (e.g. chatting, scoreboard).
Input -> WantedWeapon	Integer	Direct weapon slot selection. 0 = no desired weapon, 1+weapon = desired weapon.
Input -> NextWeapon	Integer	Next weapon cycle input.
Input -> PrevWeapon	Integer	Previous weapon cycle input.

Input Size counts the 32-bit input values before packing, so it can differ from the encoded payload length. Normal input is sent with immediate flushing; direct input can also be sent without flushing.

INFO

Check the Input & Input Timing Chunks section for more information about this chunk.

17 - NETMSG_RCON_CMD

Sent by the client to execute a command on the server through the remote console.

• Vital : ✅
• Instant Sending : ❌
• Sending Path : Client -> Server

Structure:

Field	Type	Description
Command	String	The command to be executed.

18 - NETMSG_RCON_AUTH

Sent by the client to authenticate for rcon access and request the available command list.

• Vital : ✅
• Instant Sending : ❌
• Sending Path : Client -> Server

Structure:

Field	Type	Description
Login Name	String	Login name. The server reads this field but does not use it for authentication.
Password	String	The rcon password used to authenticate.
Send Command List	Boolean	Whether the client requests the available rcon commands after authentication.

19 - NETMSG_REQUEST_MAP_DATA

Sent by the client to request the next chunk of map data.

• Vital : ✅
• Instant Sending : ✅
• Sending Path : Client -> Server

Structure:

Field	Type	Description
Chunk	Integer	Zero-based map chunk index being requested, starting at 0.

The client requests successive indices until NETMSG_MAP_DATA has Last set to 1. Each index selects a file slice starting at Chunk * 896. Reassemble the raw slices in order and verify the complete file against the announced size and CRC.

22 - NETMSG_PING

Sent by either side to request a pong response.

• Vital : ❌
• Instant Sending : ❌
• Sending Path : Both ways

Structure:

Empty payload

23 - NETMSG_PING_REPLY

Sent by either side as a reply to a NETMSG_PING.

• Vital : ❌
• Instant Sending : ❌
• Sending Path : Both ways

Structure:

Empty payload

25 - NETMSG_RCON_CMD_ADD

Sent by the server to inform an authenticated client about a newly available rcon command.

• Vital : ✅
• Instant Sending : ❌
• Sending Path : Server -> Client

Structure:

Field	Type	Description
Name	String	Command name.
Help	String	Help text describing the command.
Params	String	Parameter format string for the command.

26 - NETMSG_RCON_CMD_REM

Sent by the server to inform an authenticated client that a rcon command is no longer available.

• Vital : ✅
• Instant Sending : ❌
• Sending Path : Server -> Client

Structure:

Field	Type	Description
Name	String	Name of the command to remove.

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