How to Set Up a Core Keeper Dedicated Server

A Core Keeper dedicated server keeps your world running for the whole group, whoever is online. It is a free download from Steam, it runs on Linux and Windows, and it needs no port forwarding at all if every player is on Steam.

Option 1: by hand with SteamCMD

The Core Keeper Dedicated Server is a free, anonymous download from Steam, application 1963720, about 570 MB.

  1. Install SteamCMD, then run: +login anonymous +app_update 1963720 validate +quit
  2. On Linux, install xvfb and libxi6: part of the world generation runs on the GPU, so the server needs a (virtual) display even with no screen. Pugstorm's _launch.sh starts one for you.
  3. Start it with _launch.sh (Linux) or CoreKeeperServer.exe -batchmode (Windows), adding -worldname "Your Server" and -datapath with the folder to keep the saves in.
  4. Read GameInfo.txt next to the executable: it holds the Game ID that Steam players join with.
  5. For players on Epic, the Microsoft Store or GOG, add -port 27015 and -password, and forward UDP 27015 and 27016.
Tip:Use -batchmode, never -nographics: the server generates part of the world on the GPU and needs a display, which Xvfb provides on a headless Linux machine.

Option 2: Docker

runonflux/corekeeper-server-flux, our image, installs and updates the server with SteamCMD on every start, runs it on a virtual display, writes its settings from environment variables (CK_WORLD_NAME, CK_MAX_PLAYERS, CK_WORLD_MODE, CK_SEASON, CK_PORT, CK_ADMINS...), saves the world on stop, restarts onto new game builds, keeps backups and keeps mods on the data volume. Its source is on GitHub, RunOnFlux/corekeeper-server-flux.

  • Mount /mnt/corekeeper/data on a volume: the worlds, the settings, the admins, the bans and the mods live there.
  • Mount /mnt/corekeeper/server too, or every start downloads the 570 MB install again.
  • Publish 27015 and 27016, UDP, for players who join by IP.

Option 3: managed on Flux

Deploy a Core Keeper server on the Flux decentralized cloud, on that same image, with the ports opened and routed for you, DDoS protection included, and a dashboard with 30 world slots, the Game ID and join line, mods, admins and bans, a file browser, a live terminal and backups. Plans start at $4.49 a month.

  1. Pick the 8, 16 or 32-player plan.
  2. Choose a region close to your players.
  3. Name the world, pick its mode and deploy. The first start downloads about 570 MB.
  4. Give your Steam players the Game ID from the dashboard, and everyone else the join line.
Deploy a Core Keeper server →

Frequently asked questions

Is the Core Keeper dedicated server free?

Yes. It is a free, anonymous download from Steam (application 1963720); you do not need to own the game on the server.

Does the Core Keeper server run on Linux?

Yes, natively, on a virtual display (Xvfb): Pugstorm ships _launch.sh, which installs and starts it.

How long does a Core Keeper server take to start?

The first start downloads about 570 MB. After that, in our tests, a new world was up in 20 to 25 seconds.

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