Server setup

MyCelium mods on a dedicated server, start to finish.

MyCelium mods run on the server side, which makes them ideal for servers: install once and every player is covered, including vanilla clients who install nothing. Here is the whole process.

1. Java 25

Minecraft 26.3 and every loader in this wiki need Java 25 to run. Check with java -version on the machine hosting the server. If it reports anything older, install a Java 25 runtime first; nothing below will work without it.

2. The server jar for your loader

Fabric: use the Fabric server launcher (the installer on fabricmc.net has a Server tab). You still need to add Fabric API to mods yourself.
Forge: run the Forge installer and choose Install server. It creates the server jar and libraries for you.
NeoForge: same idea, run the NeoForge installer and choose the server option.

Run the server once so it generates its files, accept the Minecraft EULA in eula.txt, and run it again to confirm a clean vanilla startup before adding mods.

3. Add the mod jars

Stop the server, open the mods folder next to the server jar, and drop in the Mycel jar plus the mod jar(s) for your loader. Start the server again. If it finishes starting with no errors, the mods are live for everyone.

Players install nothing. That is the main perk of server-side mods. Anyone can join with a vanilla client and still get instant XP pickup or automatic refills.

4. Manage it from the console

The commands all work from the server console without the leading slash:

mycel mods                       # confirm the mods registered
mycel reload instantxp           # apply a hand-edited config
mycel info                       # versions, for bug reports

Config files live in the server's config folder. Edit them with the server stopped, or edit and reload live with the commands above.

Updating later

To update a mod, stop the server, swap the old jar for the new one, and start again. Config files are kept as-is; if a new setting appears, it is added with its default automatically. Keep a backup of the world before updating anything, same as always.