Core Keeper Dedicated Server Setup
Core Keeper's official dedicated-server flow is deliberately simple: install the Core Keeper Dedicated Server tool from Steam, launch it, copy the generated Game ID, and keep the process running. This guide follows Pugstorm's current FAQ instead of inventing a server.cfg format or unsupported port list. If you want the world online without maintaining the process yourself, compare managed Core Keeper server hosting.
Last verified: September 1, 2026. The official FAQ is the source of truth for the Steam UI labels, save paths, and join flow. The original dedicated-server announcement also says the official flow does not require port forwarding.
What you need
- A Windows or Linux machine that can stay online while friends play. Core Keeper is developed for Windows and Linux; macOS is not listed as a supported development target in the FAQ.
- Core Keeper installed on each player's platform. PC storefronts (Steam, Epic, and GOG) can play together, but console and PC cross-platform crossplay is not available.
- A backup of the world before moving or deleting files. Do not treat a server reinstall as a backup strategy.
Install the official Steam Tools app
- Open Steam and switch the library filter from Games to Tools.
- Search for Core Keeper Dedicated Server, right-click it, and choose Install.
- Launch the tool and leave Launch Dedicated Server selected, then click Play.
- Wait for the command window to print a Game ID. Press Enter once if the window is waiting for input.
- Keep the process running. The server is not available after the dedicated-server process has been quit.
Steam Library
> Tools
> Core Keeper Dedicated Server
> Install
> Launch Dedicated Server
> Play
Let friends join with the Game ID
Players launch Core Keeper, choose Join Game, and enter the Game ID shown by the server process. Share the ID only with the people who should access the world. When you finish, return to the command window and press q to quit cleanly.
The Game ID flow is different from typing an arbitrary password into a server browser. If someone reports that “nothing happens,” first confirm that they are using Join Game, that the ID is current, and that the dedicated-server process is still running. Use the connection troubleshooting checklist for the next checks.
Move or back up an existing world
The official FAQ warns owners to back up these locations before moving or deleting data:
| Use | Windows | Linux |
|---|---|---|
| Player saves and backups | C:\Users\[USERNAME]\AppData\LocalLow\Pugstorm\Core Keeper\Steam\[STEAM ID] | ~/.config/unity3d/Pugstorm/Core Keeper/Steam/[STEAM ID] |
| Dedicated-server worlds | C:\Users\[USERNAME]\AppData\LocalLow\Pugstorm\Core Keeper\DedicatedServer\worlds | ~/.config/unity3d/Pugstorm/Core Keeper/DedicatedServer/worlds |
Replace the bracketed values with the real Windows username or Steam ID. Copy the entire relevant directory to a dated backup location before an update, mod change, or migration. The troubleshooting guide covers recovery decisions if a world stops loading.
Keep client and server versions aligned
- Update the Steam Tools app before asking players to join after a game update.
- Have every player restart Steam and Core Keeper if the Game ID is accepted but the join stalls.
- Do not introduce mods while diagnosing a version mismatch. First reproduce the issue on an unmodded copy of the world.
- Read the official Core Keeper FAQ for current platform, save, and dedicated-server behavior.
Networking: what the official flow does and does not promise
Pugstorm's dedicated-server announcement says the service no longer requires port forwarding, and the FAQ's supported join path is the Game ID. That does not make a local firewall, VPN, corporate network, or a sleeping host irrelevant: test from the same network and a second network, and record whether the server process prints a new ID after a restart. Avoid publishing a made-up UDP port as a universal fix.
Mods after the vanilla server works
Core Keeper now has first-party modding documentation and a Steam Workshop open beta. Add one mod at a time, keep a clean world backup, and make sure every player follows the same mod/version instructions. The Core Keeper dedicated-server mods guide explains a safer test order.
Related Core Keeper guides
- Server connection troubleshooting
- General troubleshooting and save recovery
- Dedicated-server mods and Workshop
- Core Keeper server cost and pricing
- Admin and chat commands
Want the short path? Launch a managed Core Keeper server with backups and an always-on process, then use this wiki for world, mod, and connection decisions.