How to install Fabric mods on a Minecraft server (step by step)

Short answer: switch your server to Fabric for your Minecraft version, add Fabric API plus the mods you want to the mods folder, restart, and make sure players install the same Fabric version and mods on their game. On MACO Core this is two clicks: Version → Fabric, then Mods → Install.

What you need

A Minecraft server with enough RAM for your mods (see our RAM guide).
The Minecraft version your mods support. Mods are built for specific versions, so check this first.
Java: Minecraft 1.20.5 to 1.21.x needs Java 21. The 2026 versions (26.x) need Java 25. Older versions use Java 17 or 8.

Step 1: install Fabric on the server

On MACO Core: open your server, go to the Version tab, choose Fabric and your Minecraft version, then press Install. Your world is kept. If you are switching from plugins, tick clean content so old plugins do not clash.

Manually on another host: download the Fabric server launcher for your version from fabricmc.net, upload it as your server jar, and start the server once so it creates its folders.

Step 2: add Fabric API

Almost every Fabric mod needs Fabric API. It is a separate mod, not part of the loader. Make sure the version matches your Minecraft version.

Step 3: add your mods

On MACO Core: go to the Mods tab, search Modrinth, and press Install. Required dependencies (like Fabric API) are added for you.

Manually: download the .jar files from Modrinth or CurseForge and upload them to the server's mods folder.

Only put mods in the server's mods folder that are meant for servers. Client-only mods (shaders, minimaps, performance mods like Sodium) belong on players' games, and some will crash a server if installed there.

Step 4: restart and check the console

Restart the server and watch the console. If it starts and shows Done, you are ready. If it crashes, the error usually names the mod that caused it: often a missing dependency or a mod built for a different Minecraft version.

Step 5: set up players' games

Each player needs:

The Fabric loader for the same Minecraft version (from fabricmc.net, or a launcher like Prism or Modrinth App).
The same mods that add content (blocks, items, mobs) as the server, plus Fabric API.

Server-only mods (like Lithium for performance) do not need to be installed by players.

Good server mods to start with

Fabric API: required by most mods.
Lithium: general server performance, no client mod needed.
FerriteCore: reduces memory usage.
Simple Voice Chat: proximity voice chat (needs one extra port, which every MACO Core plan includes).

Troubleshooting

"Incompatible mods found" or a crash on start: a mod needs a different Minecraft version or a dependency you have not installed. Read the error, then update or remove that mod.

Players get "mismatched mod channel list" when joining: their mods do not match the server's. Check versions on both sides.

Out of memory errors: your mods need more RAM than your plan has. Remove heavy mods or upgrade.

FAQ

Do I need Fabric API on the server? Yes, if any of your mods require it, which almost all do.

Can I use Forge mods on Fabric? No. Forge/NeoForge mods and Fabric mods are not compatible. Some mods are released for both, so download the Fabric version.

Do players need the mods too? For mods that add content, yes. For server-only mods like Lithium, no.