BeamMP-Server/BEAMMP_PROTOCOL_DOCS.md

BeamMP Protocol Documentation

WIP of course, but hope it helps others

TCP

Basic message format

All messages are sent as strings (?). Every packet starts with a 4 byte header, denoting how many bytes the packet data is. This means that you first must read 4 bytes from your socket, to get the header data, and afterwards read the data ready for reading.

Communication flow

Upon client connection:

1. Authentication
2. Sync with client?

Authentication

1. C->S - Client sends the server a single byte. The BeamMP source checks for 3 letters, but I only saw C
2. C->S - Client sends a packet containing the client version
3. S->C - Server sends the server a regular packet containing only 1 byte: S (the ascii character)
4. C->S - Client sends the server its public key
5. S->C - Server sends the client their assigned server ID

Syncing resources

1. C->S - Client sends the server a packet with the code SR
2. S->C - Server sends the client a packet containing a filelist containing the name and size of files to download, or "-" if it's empty

Packets

All packets start with a single character, denoted as "Packet Code" or simply "Code" down below. The data mentioned is merely example data, to show the data format. This includes the code! Example:

Code	Dir	Explanation	Data
C	C->S	Client version	VC2.0

Uncategorized

Code	Dir	Explanation	Data
J	S->C	Show a message in the top left on the clients screen	JWelcome Luuk!

Authentication

Code	Dir	Explanation	Data
C	C->S	Client version	VC2.0
S	S->C	Confirmation?	None
D	C->S	Start download phase? Seems unused from testing	None
P	S->C	Send client their assigned ID	P123

Syncing resources

Code	Dir	Explanation	Data
SR	C->S	Client requests a list containing all mods, containing their name and file size	None
f	C->S	Client requests file with name	fcool_mod.zip
-	S->C	Technically not a packet, see Syncing Resources, step 2.	*

Syncing client state

Code	Dir	Explanation	Data
H	C->S	Client requests a full sync with the server state	None

Vehicle packets

Code	Dir	Explanation	Data
Os	C->S	Client informs server they are spawning a car	Os:C_ID:{car_json}
Os	S->C	Server sends this packet to all clients, informing them a client has spawned a car	Os:C_ROLES:C_NAME:C_ID-CAR_ID:CAR_JSON
Or	C->S	Client informs server they are respawning their car	Or:C_ID-CAR_ID:{respawn_json}
Or	S->C	Server informs all other clients that a client is respawning their car	Or:C_ID-CAR_ID:{respawn_json}
Od	C->S	Client informs server they are deleting their car	Od:C_ID-CAR_ID
Od	S->C	Server informs all other clients that a client is deleting their car	Od:C_ID-CAR_ID
Oc	C->S	Client informs server they are editing their car	Oc:?...
Oc	S->C	Server informs all other clients that a client has edited their car	Oc:?...

UDP

Packets

Uncategorized

Code	Dir	Explanation	Data
p	C->S	Ping!	None
p	S->C	Pong!	None

Vehicle related

Code	Dir	Explanation	Data
Zp	C->S	Positional packet	Zp:C_ID-CAR_ID:{transform_json}