Core Keeper dedicated servers do not subscribe to mods through mod.io. MaximusHost provides a manual ZIP upload flow in the server’s Mods tab. The package manager checks archive paths and the ModManifest.json file before extracting a package.

Runtime note: the upload and file-management path has not yet been verified against the current live Core Keeper server build. Treat this feature as experimental until MaximusHost completes a real server-and-client mod test. Mod packages contain third-party code; install only packages and versions you trust.

Add or update a server mod

1. Stop the Core Keeper server.
2. Create a full-server backup from Backups.
3. Download the mod’s server package from the mod author or mod.io. The dedicated server does not download a subscribed mod for you.
4. Open Mods and upload the supported ZIP package.
5. Review the package name, version, and any dependency warnings shown by the manager.
6. Enable the mod if it is not enabled already, then start the server and check Console for startup errors.
7. Install the matching mod version on every player’s Core Keeper client before joining.

To update a package, stop the server, upload the new ZIP for the existing mod, review the version, then start the server. To remove a mod, stop the server and use Remove in the Mods tab. Back up first, especially if the mod adds items or world content.

Install the matching client mod

Each player must install the same mod and compatible version in their own Core Keeper client using the mod author’s instructions. The server manager does not synchronize client files or mod.io subscriptions to players. Verify dependencies and game-version compatibility with the mod author.

Safe mod practices

• Keep the server stopped during install, update, disable, or removal.
• Use a ZIP downloaded from a mod author you trust. Core Keeper mods may include managed code that the game loads into its process.
• Keep the original ZIP until the updated server has started and players have joined successfully.
• If the server fails after a mod change, stop it, remove or disable the last changed mod, then restore a known-good backup if needed.
• Standalone .exe, shell, PowerShell, and native .so files are rejected. Managed mod assemblies are accepted because some Core Keeper mods require them; only install code from authors you trust.

The manager rejects unsafe archive paths, links, oversized archives, duplicate packages, and invalid manifests. Dependency warnings rely on the metadata supplied by a mod package and may not catch every incompatibility.

See Settings and World Options, Backups and Restore, and Troubleshooting.