Beacon - Subnautica 2 Dedicated Server

Beacon

Subnautica 2 has no dedicated server. Its multiplayer is a co-op session of up to four players, hosted from one player's copy of the game. Beacon adds a Subnautica 2 dedicated server: BeaconServer runs the game headless on a Windows machine with a public IP and port, and the Beacon app connects players to it by address.

Every player must install Beacon to join a Beacon server. Stock Subnautica 2 cannot connect to a Beacon server directly.

What it does

• Join a server by IP and port from the Beacon app, with an optional join password.[/*]

• Friends join whenever the server is running, whether or not the owner is playing.[/*]

• Characters are kept per server and tied to each player's Steam account.[/*]

• In-game text chat (press Enter) on servers that offer Beacon's chat overlay; a self-hosted BeaconServer does not include it. Server notices and admin announcements show in the same panel.[/*]

• The Map button in the app opens a web map of the world with the connected players on it.[/*]

• Server admin: Source RCON (help, status, players, say, announce, motd, save snapshot, save list) and Source A2S query for server lists, monitoring tools and bots.[/*]

• A self-hosted server takes a snapshot of the world on every game auto-save.[/*]

Requirements

• Windows 10 or 11, 64-bit. No Mac or Linux version.[/*]

• Subnautica 2 from Steam. Every player needs their own copy.[/*]

• Nothing else from Nexus. Beacon carries its own copy of UE4SS.[/*]

Beacon is tested with the Steam version of Subnautica 2. Other PC versions are not covered, and consoles cannot run Beacon.

Install (players)

• Download the Beacon installer from Files, or BeaconSetup-latest.exe from the latest GitHub release, and run it. It installs for your Windows user only. The installer is not code-signed, so Windows SmartScreen may warn: choose More info, then Run anyway.[/*]

• Open Beacon and click the + button (Add server). Fill in a name, the server's IP or host name and its port, and the server password if it has one.[/*]

• Select the server. Type a player name, and Beacon makes a character with that name on this server, or click Characters to pick one.[/*]

• Click Connect. Beacon starts Subnautica 2 through Steam and joins the server.[/*]

An installed Beacon checks for updates by itself. To remove it, uninstall Beacon from Windows' installed apps list.

Install (server hosts)

• Download Beacon-Server-Windows-x64-v<version>.zip from the latest BeaconServer release and extract it to a fixed folder, for example C: Beacon .[/*]

• Copy your own Subnautica 2 game files into C: Beacon game, or install them with SteamCMD (app 1962700). The download does not include the game.[/*]

• Keep the Steam client running on that machine, signed in to an account that owns Subnautica 2, under the same Windows user and session as BeaconServer.[/*]

• Edit BeaconServer appsettings.json (server name, ports, RconPassword, BeaconAuthPassword), open the gameplay port (UDP), query (UDP, +2), RCON (TCP, +3) and admin HTTP (TCP, +4), and run BeaconServer BeaconServer.exe.[/*]

Full setup: BeaconServer README. Starting a brand-new world on a self-hosted server is not covered here.

Known issues

• The server and every player must be on the same Subnautica 2 build. After a game update, players on the new build can fail to join an older server, or get disconnected near something the update changed. Update the server's game files whenever the game updates.[/*]

• Self-hosted: "The game was not started via the platform launcher and will be closed." means the server machine's Steam client is not running, not signed in to an account that owns the game, or not in the same Windows session as BeaconServer.[/*]

Bugs and source

Report bugs on GitHub with your Beacon and BeaconServer versions, the Subnautica 2 build and the relevant lines from the server's logs beacon-*.log.

Beacon is free. The Beacon app and its in-game runtime are closed source and for personal use. BeaconServer, the dedicated server, is open source under the MIT licence: github.com/HumanGenome/BeaconServer. Each file in the server download keeps its own licence.

Credits

• UE4SS: Unreal Engine scripting and modding framework[/*]

• Avalonia: the UI framework behind the Beacon app[/*]

• joric/subnautica (Unlicense): the interactive Subnautica 2 map behind the web map[/*]

• MultiplayerChat by TheMC: first showed the approach Beacon's in-game chat uses (typing through UE4SS key binds, holding the player still while typing, and showing chat in the game's own HUD text). Beacon's chat code is its own.[/*]

Beacon is a community project and is not affiliated with or endorsed by Unknown Worlds, the developers of Subnautica 2.

Managed hosting: SurvivalServers.com runs Subnautica 2 servers with BeaconServer already installed.