Core Keeper Dedicated Server Mods
Core Keeper has first-party modding documentation and a Steam Workshop open beta. That is useful, but it is not a promise that every mod or older save survives every game update. Use a reversible rollout: prove the vanilla server joins, back up the world, add one mod, and have every player test the same build.
Last verified: September 1, 2026. Start with the official Core Keeper modding documentation and the Workshop guidance linked from the official FAQ.
Safe mod rollout
| Stage | What to do | Pass condition |
|---|---|---|
| Clean baseline | Launch the Dedicated Server tool and join with the Game ID. | Two clients can load the world without mods. |
| Backup | Copy the dedicated-server worlds directory to a dated location. | You can identify the backup and restore it without guessing. |
| One change | Install one documented mod or Workshop item and restart the server. | Server starts, clients join, and the new feature works. |
| Repeat | Add the next mod only after the previous test passes. | A failing change has a short rollback path. |
Keep the group in sync
- Give players the same mod names, versions, and load order instructions.
- Update the game and server tool before updating the mod set.
- Do not mix mod debugging with a Game ID or network investigation; reproduce on a clean copy first.
- Keep the old backup until everyone has joined, saved, and rejoined successfully.
When a mod breaks joining
- Stop the server cleanly and save the logs.
- Remove or disable only the newest mod, then restore the last known-good copy if the world will not load.
- Test the clean server with the current Game ID.
- Check the mod's documentation and Workshop page for game-build requirements before trying it again.
Recent Workshop support is still described as an open beta, so avoid treating an old community tutorial as a current server contract. The connection troubleshooting guide covers the symptoms that look like a mod failure but are actually a stale ID or version mismatch.
Backups and world paths
The official FAQ lists player saves under %USERPROFILE%\AppData\LocalLow\Pugstorm\Core Keeper\Steam\[STEAM ID] on Windows and ~/.config/unity3d/Pugstorm/Core Keeper/Steam/[STEAM ID] on Linux. Dedicated-server worlds are under the corresponding Core Keeper/DedicatedServer/worlds directory. Back up before touching either location.
Related Core Keeper guides
- Dedicated server setup and Game ID
- Connection troubleshooting
- Admin and chat commands
- Save and performance troubleshooting
- Server cost and plan sizing
Prefer a controlled environment? Supercraft Core Keeper hosting provides an always-on server process and backups; keep the same one-change-at-a-time discipline for mods.