How to Set Up a Core Keeper Dedicated Server

Core Keeper's underground sandbox is a joy in co-op, and a dedicated server keeps your cave world persistent so friends can mine and build even when you're offline. It's one of the lighter survival servers to run, and it has a native Linux build. This guide covers the full setup, including Core Keeper's slightly unusual Game ID connection model.

What you need

• A Linux VPS: Ubuntu 22.04/24.04. Core Keeper is light — 4 GB RAM comfortably runs a small group.
• How players connect: Core Keeper uses a Game ID (not just an IP and port) via Steam's networking, so you typically don't need to forward a game port for friends to join.

Step 1: Create a user and install dependencies

sudo adduser --disabled-password --gecos "" corekeeper
sudo dpkg --add-architecture i386
sudo apt update
sudo apt install -y lib32gcc-s1 steamcmd xvfb

Core Keeper's server expects a virtual display, which is why we install xvfb (a headless X server).

Step 2: Install the server with SteamCMD

The Core Keeper dedicated server is App ID 1963720 with a native Linux build:

sudo su - corekeeper
steamcmd +force_install_dir /home/corekeeper/server +login anonymous +app_update 1963720 validate +quit

{{SCREENSHOT}}

Step 3: Configure the server

Core Keeper's settings are set via environment variables or the launch script. The key ones:

• world name / save name — which world to load or create.
• max players — the slot count for your group.
• world seed and game mode — the seed and whether it's a normal or hard world.

Edit the provided _launch.sh (or set the environment variables it reads) to name your world and set the player cap.

Step 4: Run it as a systemd service

Because the server needs a virtual display, wrap the launch with xvfb-run. Create /home/corekeeper/start.sh:

#!/bin/bash
cd /home/corekeeper/server
xvfb-run -a ./_launch.sh

chmod +x /home/corekeeper/start.sh

# /etc/systemd/system/corekeeper.service
[Unit]
Description=Core Keeper Dedicated Server
After=network-online.target

[Service]
Type=simple
User=corekeeper
ExecStart=/home/corekeeper/start.sh
Restart=on-failure
RestartSec=10

[Install]
WantedBy=multi-user.target

sudo systemctl daemon-reload
sudo systemctl enable --now corekeeper
sudo journalctl -u corekeeper -f

Step 5: Find the Game ID and join

On first launch, the server writes a Game ID to its log and data files. Watch the log for it:

sudo journalctl -u corekeeper -f

Share that Game ID with your friends. In Core Keeper, they choose Join Game → enter Game ID and they're in — no IP or port required. Keep the server updated by re-running the +app_update 1963720 command whenever Core Keeper patches, or automate it.

Back up your world

Core Keeper stores worlds in its data directory (under the server user's home). Because the whole point of a dedicated server is a persistent world your group returns to, back it up on a schedule:

# nightly backup, keep a week
0 4 * * * tar -czf /home/corekeeper/backups/ck-$(date +\%F).tar.gz /home/corekeeper/.local/share/CoreKeeperServer && find /home/corekeeper/backups -name 'ck-*' -mtime +7 -delete

Core Keeper is light enough that you could comfortably run it alongside another small service on the same box — a scheduled restart from automating game server restarts with systemd keeps it fresh, and how to back up your game server automatically covers a fuller routine.

FAQ

How do players join a Core Keeper dedicated server?

Via the server's Game ID, which appears in the server log on first launch. Players enter that ID in the game's Join menu — no IP or port forwarding needed, thanks to Steam networking.

How much RAM does a Core Keeper server need?

It's light — 4 GB comfortably handles a small group. A larger, long-lived world with more players benefits from a bit more, but Core Keeper is far less demanding than Rust or ARK.

Why does the Core Keeper server need xvfb?

The Linux server expects a display context. Running it through xvfb-run provides a headless virtual display so it starts cleanly on a server with no GPU or monitor.

Where do I find the Core Keeper Game ID?

In the server's log output (via journalctl) and its data directory after the first successful launch. Share it with anyone you want to join.

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