Don't Starve Together uses Steam Workshop mods, which add characters, items, game rules and interface changes, and the server downloads and loads them for both the surface world and the caves.
Back up first. See How to back up and restore your Don't Starve Together world.
Add a mod
- Find the mod on the Steam Workshop and copy the number at the end of its page address, the number after id=.
- Open the Workshop tab of your server, or open Settings, then Game Settings, and put the numbers in Steam Workshop Mods, separated by commas with no spaces. Only digits and commas are accepted.
- Restart the server. It downloads the mods itself on this start, so the start takes noticeably longer than usual. Let it finish.
- The panel writes the server's mod files from this one list on every start, so do not edit the mod files yourself: your changes are replaced. This also means a mod's own configuration options cannot be changed through those files.
- To remove mods, take their numbers out of the list and restart. Emptying the list puts the server back to unmodded. A mod that added items or creatures can leave missing or broken things in an existing world, so make a panel backup first and remove one mod at a time.
Players need the same mods
Everyone who joins needs the same mods and versions as the server.
Check it worked
Read the Console during startup and look for the mod's number or name. If you cannot find it, check the Steam Workshop Mods list. Players download the server's Workshop mods automatically from the Steam Workshop when they join. See How to add mods, plugins and modpacks.
If the server stops after you add a mod, remove the newest mod or restore your backup. See How to fix a server that will not start.
