PhotonDocs

This is a repository to share documentation about the photon protocol that VRChat uses.

Tools (feel free to add yours)

ImHex will be used to document a bunch of the binary formats here and is a really neat reverse engineering tool to have

PhotonDebug Is a photon debug tool made by HentaiHeaven#0001 and logs all photon data to json log files.

OpCodes

Official documentation

VRChat specific documentation for OpCodes:

Code	OpCode Name	Description	Docs
217	GetRoomList
219	WebRPC
220	GetRegions
221	GetLobbyStats
222	FindFriends
225	JoinRandomRoom
226	JoinRoom
227	CreateRoom
228	LeaveLobby
229	JoinLobby
230	Authenticate
231	AuthenticateOnce
251	GetProperties
252	SetProperties
253	RaiseEvent
254	Leave
255	Join

Events

These are events that can be sent by invoking Operation RaiseEvent (253)

Code	Event Name	Description	Authoritative	Docs
1	Voice	Voice transmission via uSpeak.	No.	format
2	ExecutiveMessage	Used by backend to communicate alerts to clients.	Yes.	format
3	PastEvents	Used to request the past events of an instance.	No. (Only send to Master)	format
4	SyncEvents	Used as a response to SendPastEvents	No.	format
5	SyncFinished	Marks a SendPastEvents request as finished.	No.	format
6	ProcessEvent	Broadcast Used for VrcEvents (like RPCs).	No.	format
7	Unreliable Serialization	Used for any type of data that can be interpolated or doesn't have to be sent reliably.	No.	format
8	InterestManagement	Used for interest list sync.	Yes.	format
9	Reliable Serialization	Used for any type of data that should always be reliably sent like AV3 parameters, Udon Sync and late joiner position sync for players and pickups.	No.	format
33	ExecutiveAction	General Moderation event.	Yes.	format
34	RatelimitValueSync	In-game rate-limiter	Yes.	format
35	RatelimitUpdate	Update Tick for Ratelimited Actors	Yes.	format
40	UserRecordUpdate	Used to update a user's details.	Yes.	format
42	UserRecordUpdate.. 2?	Very similar to Event 40, added in build 1169 in preparation for the IK beta.	Yes.	format
60	PhysBonesPermissions	Used to compute which actors can interact with which in an instance.	???	format
202	Instantiate	Used to instanciate self in lobby.	???	format
209	OwnershipRequest
210	OwnershipTransfer
211	VacantViewIds
223	Photon AuthEvent

Misc

ViewID list

• 00001: VRCPlayer
• 00002: USpeak
• 00003: PlayableController
• 00004: BigData