Network Protocols

The multiplayer networking for Gravity Box Arena is based on JavaScript WebSockets, and has a NodeJS backend.

This page will document various aspects of the networking.

Packets

Packets are individual packages of data that get sent to and from the server. This section will go over how a packet is structured, as well as any specific codes you will need.

Note: All numbers should be encoded in big endian for consistency.

Packet Layout (Client)

Byte Index	Description
0	The packet type identifier.
1-5	The player key.
6-	Any extra data.

Packet Layout (Server)

Byte Index	Description
0	The packet type identifier.
1-	Data.

Packet Type Identifier

The packet type identifier is used to identify what kind of data a packet contains. Below is a table of identifiers and their meanings.

Identifier	Name	Description
1	REQUEST_AUTH	Request authorization from the server. The server will respond with a generated player key (5-byte string).
2	REQUEST_JOIN_OR_CREATE_LOBBY	Request to join a lobby. If a lobby is not found, create and join one. The server will respond with the lobby ID (32-bit signed integer, big endian).
3	SYNC_DATA	Sends the packet data to all other clients in the sender's lobby.

Disconnect Codes

Disconnect codes are sent when a user is disconnected by the server.

Code	Name	Description
1	BAD_PACKET	The server received a packet with a nonexistent identifier.