Core Keeper Server Setup: How to Run a Dedicated Server

A Core Keeper server setup comes down to four things: the dedicated server itself (Steam app 1963720, which downloads without a login), a handful of launch arguments for the world, a way for your friends to connect, and a machine that stays on. Steam players join with a Game ID and need no open ports; players on Epic, GOG or the Microsoft Store need direct connections with an IP, port and password. Everything below comes from the README and ARGUMENTS files that Pugstorm ships with the server.

How joining a Core Keeper dedicated server works

Decide this first, because it changes the setup. The server has two ways to accept players:

Cross-store play arrived in patch 1.1.2.3 (August 2025), as Pugstorm announced in its Steam news. The README adds a warning worth repeating: with direct connections, the server’s IP is shared with players and the players’ IPs with the server. If everyone in your group plays on Steam, the Game ID route is simpler.

Core Keeper server setup: install the server

You can install “Core Keeper Dedicated Server” from your Steam library, or download it with SteamCMD. The official README gives this line, and no Steam account is needed:

steamcmd +login anonymous +app_update 1963720 +quit

Things the README tells you before the first start:

• The server comes with a launch script. On Linux, _launch.sh starts it inside Xvfb so it can run on a machine without a monitor.
• If you start CoreKeeperServer by hand, add -batchmode but not -nographics: part of the world generation runs on the GPU.
• On start, the server writes GameInfo.txt next to the executable with the Game ID and the connection details. If that file never appears, open CoreKeeperServerLog.txt in the same folder and look for the error.

Core Keeper server config: the launch arguments

Every setting is a launch argument, documented in ARGUMENTS.txt. These are the ones you will actually use:

Two limits from the official docs catch people out. Switching a world between Creative and the other modes after it is created is not supported, so choose the mode before the first start. And content bundles stay on forever once activated, so make a copy of the world before you use -activatecontent.

Here is a typical launch line for a Steam-only server with a fixed Game ID, so the code you give your friends never changes:

-batchmode -world 0 -worldname "Our Cave" -worldmode Normal -maxplayers 8 -gameid WH3rhzuk5TfbA4jFuZPg7SmbCHES

Add -port 27015 -password "YourPassword" only if you need players from other stores.

ServerConfig.json

Most arguments are also saved in ServerConfig.json inside the server’s data path, so you can edit them there instead of in the launch line. The exceptions are -port and -ip: the official docs say setting them in ServerConfig.json has no effect. Stop the server before editing the file, then start it again.

How your friends connect

Open GameInfo.txt. It lists the Game ID, the platforms allowed to join, any arguments the server ignored, and, when -port is set, the local and public IPs, the port and the password. It also includes a ready-made IP;PORT;;PASSWORD string: players paste it into the IP field of the “Join Game Via IP” menu and the game splits it into the right fields.

• Steam players: join with the Game ID. The password is not used with the Game ID, because the ID alone already grants access, so treat it like a password and don’t post it publicly.
• Epic, GOG and Microsoft Store players: use “Join Game Via IP” with the IP, port and password.

Using your own world settings

The dedicated server has no world-generation menu. The README’s workaround: create a world in the normal game with the parameters you want, find its file in the worldgenparams folder of your save, copy it into a worldgenparams folder in the server’s data path, rename it to the world index you will use and start a new world on that index. For the exact same map, use the same seed too. If you have mods, every player needs the same ones installed, as Pugstorm reminded when cross-store play launched.

Common problems and what they mean

• The Game ID changes after every restart. You did not set -gameid, or the value was invalid (too short, too long or with a forbidden character), so the server generated a random one. GameInfo.txt lists arguments it ignored.
• Non-Steam friends can’t find the server. A Game ID only works in the Steam client; Pugstorm renamed it “Steam GameID” in patch 1.1.2.4 to make that clear. Other stores need -port.
• Direct connection times out. The port is not open in the firewall or not forwarded in the router. IPv6 addresses are accepted since patch 1.1.2.4.
• The server closes right after starting. Read CoreKeeperServerLog.txt. Since patch 1.0.0.14 the log explains when the GPU or graphics driver lacks a required feature.

Skip the setup: Core Keeper on TheGameHosting

The weak spot of a home server is that the world only exists while that PC is on. If the host goes to sleep, nobody can go back to the base. A Core Keeper server from TheGameHosting is online 24/7 and is ready about 60 seconds after payment. You read GameInfo.txt and edit ServerConfig.json from Files in the browser (or over SFTP), restart from Console, keep copies of the world in Backups before you activate content bundles, and use Schedules for automatic restarts. To see which options the panel exposes for this game, look at the Startup tab, or ask us in the chat.

Core Keeper is light: it needs 2 GB of RAM on our plans, and the 2 GB plan costs $1.90/month. It runs on AMD Ryzen 9950X and 7950X3D CPUs up to 5.7 GHz with DDR5, Samsung NVMe and a 10 Gbps network with DDoS protection, in Dallas or Amsterdam. If your group gets bored of the caves, the Game Changer switches the same plan to another of our 60+ games, such as the survival worlds in our guide to Enshrouded server settings.

Step-by-step summary

1. Install the server from Steam Tools or with steamcmd +login anonymous +app_update 1963720 +quit.
2. Pick the mode and name with -worldmode, -worldname and -world before the first start.
3. Set a fixed Game ID with -gameid (15 to 28 characters, no Y, y, x, 0 or O).
4. Add direct connections with -port and -password only if players use other stores, and open that port.
5. Start the server with -batchmode and wait for GameInfo.txt.
6. Share the connection: Game ID for Steam, the IP;PORT;;PASSWORD string for everyone else.

If you would rather spend the evening digging than reading README files, a hosted server is the shortcut. See TheGameHosting plans and pricing: Core Keeper fits in the 2 GB plan ($1.90/month), with unlimited slots, no setup fee and cancellation any time. And if you are still deciding whether you need one, read what a dedicated server is.

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