OpenPhoton

A self-hostable realtime server implementing the Photon Server 5 protocol.

Build

Requires .NET 8 SDK or newer.

dotnet build src/OpenPhoton.Server

Run

dotnet run --project src/OpenPhoton.Server -- --host 192.168.1.50

Use --help to see all options.

--host must be an address reachable by connecting clients:

• Same machine: 127.0.0.1
• LAN: your LAN IP
• Internet: your public IP or hostname

Ports

Role	TCP	UDP (pre-2022)	UDP (2022+)
NameServer	4533	5058	27000
Master	4530	5055	27001
GameServer	4531	5056	27002

All ports are opened by the server. If hosting across a firewall or NAT, forward the required TCP and UDP ports.

Both UDP port generations are supported for compatibility with different Photon client versions.

The name server can also listen on secure WebSocket (WSS) port 443. Supply a PEM certificate and key to enable it:

openphoton --host your.server.example --wss-cert cert.pem --wss-key key.pem

Use --wss-port to change the port. Clients using AuthOnceWss connect to the name server over WSS, then use their configured transport for the master and game servers.

Plugins

Place plugins in plugins/ with a Photon-format plugin.config.

Existing Photon plugin directories can be copied over unchanged.

Plugins target PhotonHivePlugin version 1.1.0.24499, provided by src/OpenPhoton.HivePlugin.

Authentication

Authentication is disabled by default.

To use a custom authentication service:

openphoton --auth-url https://your-api.example/photon/auth

The service should return a response such as:

{
  "ResultCode": 1,
  "UserId": "alice",
  "Nickname": "Alice"
}

ResultCode: 1 accepts the client; any other value rejects it.

Use --require-auth to also reject clients that provide no authentication credentials.

Compatibility

Supported:

• GpBinary V16 and V18
• TCP, reliable UDP, and secure WebSocket for the name server
• Diffie–Hellman and AES-256
• AuthOnce token handoff and payload encryption
• NameServer → Master → GameServer handoff
• Rooms, actors, properties, events, interest groups, and event caching
• Lobbies, room listings, and random matchmaking
• Rejoin and TTLs
• PhotonHivePlugin, including HTTP and timers
• Custom authentication

Not supported:

• WebRTC transport
• Multi-machine deployments
• Photon Chat
• WebRPC
• Persistent rooms
• Platform authentication such as Steam or Oculus

License

AGPL-3.0.

OpenPhoton is a clean-room implementation and contains no Exit Games code. It is not affiliated with Exit Games GmbH. "Photon" is a trademark of Exit Games GmbH.