How to Make a Core Keeper Server
A complete walkthrough for running your own Core Keeper dedicated server — install it with SteamCMD, handle the one quirk (it needs a virtual display even headless), open the ports and mine 24/7 with your friends. Plus the one-click hosted route if you'd rather skip the setup.
Core Keeper ships a free dedicated server (Steam app 1963720, separate from the game). It runs on Linux, with one catch: it's a Unity game that needs a graphics context even when headless, so you run it under xvfb (a virtual X server). You can self-host it or use a managed host that handles that for you.
This guide covers the self-hosted SteamCMD route step by step.
What you'll need
A quick checklist before you begin — have these ready and the rest is easy.
- A machine to run the server, or a host for 24/7 uptime.
- SteamCMD, to download the free server (app 1963720).
- xvfb installed (Core Keeper needs a virtual display).
- Open ports: UDP 27015 and 27016.
- A modest CPU and a few GB of RAM.
Set up a Core Keeper dedicated server, step by step
Choose self-host or a managed host
The server is free, but self-hosting needs a machine on 24/7, port-forwarding and the xvfb setup. A managed host gives you an always-online world in minutes. Want zero hassle? Pick a host and skip to step 5.
Install with SteamCMD
The Core Keeper dedicated server is Steam app 1963720 (not the game, 1621690) — a free, anonymous download.
steamcmd +login anonymous +force_install_dir ./corekeeper +app_update 1963720 validate +quit
Set up a virtual display (xvfb)
Core Keeper is built on Unity and needs a graphics context even headless. Install xvfb and launch the server with xvfb-run so it has a virtual X server without a real GPU.
sudo apt install xvfb xvfb-run ./_launch.sh
Configure the world
Set the server name, the world seed/name, game mode and max players in the server config. Core Keeper generates a persistent world your group shares.
Open the ports
Forward UDP 27015 and 27016 so players can find and join. On a managed host this is opened for you.
27015/udp 27016/udp
Share & play
Give players the IP (or the world/game ID). The server keeps the world saved and online 24/7, so co-op progress carries between sessions. Back up the save folder regularly.
Run a stable world
xvfb is the key step
The one thing that trips people up: Core Keeper needs a virtual display. Launch with xvfb-run and it works headless — miss it and the server won't start.
It's light on hardware
A modest CPU and a few GB of RAM run a full co-op world. Core Keeper is far lighter than big survival games.
Back up the world
Your world lives in the save folder. Back it up before updates so a bad patch never costs your mining progress.
Small co-op groups
Core Keeper is built for small groups (up to ~8-10). You don't need a big plan — a modest one covers a full party.
Common problems & fixes
Hit a snag? These are the issues people run into most — and how to solve them.
The server won't start / crashes immediately
It needs a virtual display. Install xvfb and launch with xvfb-run — this is the #1 Core Keeper hosting gotcha.
Players can't find the server
UDP 27015-27016 aren't open. Forward both, or share the world/game ID for a direct join.
The world reset
A moved or corrupted save. Restore from a backup of the save folder and avoid editing it while the server runs.
Lag with a full party
Give the server a slightly faster CPU. Core Keeper is light, but a busy world in one area benefits from a modern core.
Skip the setup — host it with ESAGAMES
Want a Core Keeper world online 24/7 without the xvfb hassle? Our game server hosting handles the setup and runs on high-clock CPUs behind a protected Frankfurt network — online in minutes.
Frequently asked questions
Do I need to own Core Keeper to host a server?
No. The dedicated server (Steam app 1963720) is a free, anonymous download, separate from the game (1621690). You only need the game on the machines that play.
Why does the Core Keeper server need xvfb?
Core Keeper is a Unity game that requires a graphics context even when run headless. xvfb provides a virtual X server (a fake display) so the server can start on a machine with no real GPU. Launch it with xvfb-run.
What ports does a Core Keeper server use?
UDP 27015 and 27016. Forward both so players can find and join the server. On a managed host these are opened for you.
How much hardware does a Core Keeper server need?
Not much — a modest CPU core and a few GB of RAM run a full co-op world comfortably. It's one of the lighter co-op survival games to host.
How many players can a Core Keeper server hold?
Core Keeper co-op is small — typically up to about 8-10 players. It's designed for a party, not a large server, so a modest plan covers it.
Does the world stay saved when I log off?
Yes — a dedicated server keeps the world persistent and online 24/7, so your group can keep playing and progress carries between sessions.
Keep reading
Core Keeper is a trademark of Pugstorm / Fireshine Games. ESAGAMES is an independent hosting provider, not affiliated with or endorsed by them. You must own a legitimate copy of the game to play.
