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.

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 and reliable UDP
• Diffie–Hellman and AES-256
• 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:

• WebSocket or WebRTC transports
• 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.