How to Install Mods on a Core Keeper Server (mod.io)

To install mods on a Core Keeper dedicated server, download each mod from mod.io with Download File, unzip it into CoreKeeperServer_Data/StreamingAssets/Mods/ so every mod has its own folder with ModManifest.json directly inside, add its dependencies such as CoreLib, and restart. The server does not download mods itself and does not send them to players, so every player installs the exact same mods and versions. On a Linux server, mods that add items or art only load if the author built a Linux asset bundle.

What you are working with

The Core Keeper modding docs are clear on the key point: dedicated servers have no mod.io integration, so mod files are managed by hand.

What works on a server and what does not

Before you start

• Back up the world. Mods that add items save them into the world, and removing the mod later can leave gaps.
• Check the game version. Mods are built against a game version, and a mod for an older update may not load on the current one. Use the version filter on mod.io.
• List dependencies. Many mods need a library mod such as CoreLib. The mod page lists them.

Step 1: Download the mods

On each mod's mod.io page, click Download File and save the zip. Download every dependency the page lists the same way. Pick the version that matches your game build.

Step 2: Unzip each mod into its own folder

On your PC, unzip each mod so you get one folder per mod. Open each one and check that ModManifest.json is directly inside, not inside another subfolder:

Mods/
  CoreLib/
    ModManifest.json
    ...
  EnemyHealthBars/
    ModManifest.json
    ...

Step 3: Upload to the server's Mods folder

Stop the server. Upload the mod folders into:

CoreKeeperServer_Data/StreamingAssets/Mods/

Create the Mods folder if it does not exist yet. A fresh server does not have one.

Step 4: Start and check the log

Start the server and read the console. Mods are listed as they load. If one is missing, its folder is nested too deep, a dependency is missing, or it was built for another game version.

Step 5: Give players the same mods

Nothing reaches players automatically. Everyone has to install the same mods at the same versions before they join. The modding docs suggest the cleanest way:

1. Players unsubscribe from all mods in the game's mod.io browser.
2. You zip the server's Mods folder and share it.
3. Each player unzips it into their game's CoreKeeper_Data/StreamingAssets/Mods/ folder (in the Steam install folder, under steamapps/common/Core Keeper).

Then everyone is on the exact files the server runs. When you update a mod on the server, share the folder again.

The Linux asset bundle trap

This catches most people who try content mods on a rented server. The mod SDK always builds a mod's art and content as <ModName>_Windows.assetbundle, but it only builds <ModName>_Linux.assetbundle if the author ticks the Linux option. Any server on a Linux machine runs the Linux server build, and that includes ours.

So a mod that adds a new weapon or creature works perfectly in your own game on Windows, loads on the server without an obvious error, and its items simply never exist. Script only mods are not affected.

Before you plan a modded world, open each content mod's folder and look for a _Linux.assetbundle file. If it is missing, ask the author for a Linux build, or leave the mod out.

Common problems

• Mod does nothing on the server: it adds content but has no Linux asset bundle, or ModManifest.json is one folder too deep.
• Players get errors or strange items after joining: someone has a different version of a mod, or a mod the server does not have. Share the server's Mods folder again.
• Server will not start after a game update: a mod was built for the previous version. Remove mods one at a time to find it, then wait for an update.
• Subscribed in game but the server ignores it: subscriptions only download to your PC. Upload the files to the server's Mods folder.
• Missing dependency in the log: download the library mod it names, such as CoreLib, and upload it next to the others.

Mods on GamezServers

On a GamezServers Core Keeper server, upload mod folders to CoreKeeperServer_Data/StreamingAssets/Mods in the Files tab, where you can upload a zip and extract it, or over the SFTP login in Settings. Press Backup before adding content mods, and leave Auto Update on so the server matches players after each game update. Our servers run the Linux server, so check content mods for their Linux bundle first. To bring your current world along, see how to move a Core Keeper world to a dedicated server.

FAQ

Where do mods go on a Core Keeper dedicated server?

In CoreKeeperServer_Data/StreamingAssets/Mods/, one folder per mod with ModManifest.json directly inside. Create the Mods folder if it is missing.

Do players need the same mods as the server?

Yes. The server does not send mods to players, so everyone installs the same mods and versions before joining.

Why does a mod work in my game but not on the server?

Usually it has no Linux asset bundle, so a Linux server skips its content. Script only mods are not affected.

Can the server download mods from mod.io by itself?

No. The dedicated server only loads mods from its own Mods folder, so you upload the files yourself.