Adding Steam Workshop mods to a Project Zomboid server means putting two values in your servertest.ini for every mod, the numeric Workshop ID on the WorkshopItems line and the text Mod ID on the Mods line, then restarting so the server downloads and loads them.
Two IDs for every mod
Project Zomboid needs two different pieces of information for each mod, and this trips up almost everyone at first.
- The Workshop ID is the number in the mod's Steam Workshop web address, the part after ?id=. This tells the server what to download.
- The Mod ID is a short text name, like BritaWeapons`. It tells the game which mod inside that download to switch on. You will find it in the mod's Workshop description, and a single Workshop item can contain several Mod IDs.
Miss either one and the mod simply will not load, usually with no obvious error.
Add the mods to servertest.ini
- On the Files tab, open your servertest.ini.
- Find the WorkshopItems= line and add each Workshop ID, separated by semicolons.
- Find the Mods= line and add each Mod ID, again separated by semicolons.
- Save the file and restart the server from the Console tab.
Your lines will look something like this:
WorkshopItems=2392709985;2657084703
Mods=Bandits;VFExpansion1
On the first restart the server downloads the mods from Steam, so give it a few minutes and watch the Console log.
Load order matters
Mods load from left to right in the order you list them on the Mods= line, and the last mod to touch something wins. As a rule, put framework and library mods first, then content mods, then any patches or compatibility mods that a mod author tells you to load afterwards. If two mods clash, changing their order is often the fix.
Map mods need one more line
Map mods also need a Map= line. Add the mod's map folder name before the base map, separated by semicolons, like this:
Map=MyCoolMap;Muldraugh, KY
Always keep Muldraugh, KY last so the base game map still loads.
Adding mods to a world already in progress
You can add mods to a running save, and most content mods, like new weapons or clothing, are safe to bolt on. Take a snapshot on the Backups tab first, then add the mod and restart.
Be careful the other way around. Removing a mod mid-save can wipe the items or vehicles it added and, with map mods, can corrupt the chunks players have already explored. Avoid removing map mods once a world has used them. If a mod says it is not safe for existing saves, believe it and test on a fresh world first.
Check the console
After the restart, read the Console log. Missing Mod IDs, load-order clashes and failed downloads all show up there, which makes fixing them much faster than guessing.
Still stuck? Jump into our Discord at discord.gg/GuavaHost and the team will help you out.