How to Add Mods to a Project Zomboid Server (Steam Workshop)
In Project Zomboid the server downloads Steam Workshop mods by itself. All you have to give it is two lists, in the right order.
The two lists: Workshop ID and Mod ID
Every mod has a number on the Workshop (Workshop ID): it's the “id=” in its page's address. And one or more internal names (Mod ID), which the author puts in the description (“Mod ID: …”). The server needs both.
In servertest.ini they go on two lines: WorkshopItems= with the numbers and Mods= with the names, separated by semicolons. In Build 42 (the normal Steam version since 29 July 2026) each name also has a backslash in front. For example, with Proximity Inventory and Rain Cleans Blood: WorkshopItems=2847184718;2956146279 and Mods=\ProximityInventory;\RainCleansBlood.
To avoid mistakes, the mod list tool writes both lines for you from the Workshop links and the Mod IDs, with the backslash in place.
Without that backslash, mods don't load in Build 42 and the server doesn't warn you: it's the most common mistake when bringing over a Build 41 list (what else changes from 41 to 42).
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Step by step
Note down both values for each mod
The number from the address and the Mod ID from the description. If the mod depends on another (it says so under “Required items”), note that one down too.
Put them in order
Dependencies first, then the mods that use them. The wrong order is the most common reason a mod doesn't load.
Maps: one more line
Added maps also go on Map=, before the base map and separated by semicolons, for example Map=YourMapName;Muldraugh, KY. Which ones are up to date with Build 42 and how to let players spawn on them is in the Workshop maps guide.
Restart
The server downloads the mods on start. Players download them automatically when they join.
With NapNodes
You don't need to touch the .ini: in the panel's “Mods” tab you add them by name or Workshop link, without backslashes; restart and you're done: the panel adds the Build 42 backslash. If you edit the .ini by hand, you have to add the backslash yourself.
NapNodes servers install the stable Steam version, which today is Build 42: look for mods that say they work on it. The “Mods” tab warns you about mods marked as Build 41 only, and here are the best ones for multiplayer, checked on 42.
Common errors
“Workshop item version is different than server's”: a mod has been updated on the Workshop and the server still has the old version. Restarting the server fixes it, because it downloads the new one (more on version errors).
A mod made for another version of the game (Build 41 versus Build 42) won't load or breaks the game: check its page to see which version it's for.
Frequently asked questions
Where do I find a Zomboid mod's Workshop ID?
In the address of its Steam Workshop page: it's the number after “id=”.
Where do I find the Mod ID?
In the mod's description, where the author writes “Mod ID: …”. Some mods have several.
Why do I get “Workshop item version is different than server's”?
Because the mod has been updated and the server still has the old version. Restart it so it downloads the new one.
Do players have to subscribe to the mods?
No: when they join the server, the game downloads them automatically.
Why won't my mods load in Build 42?
Almost always because of the backslash: in Build 42 every Mod ID on the Mods= line has a \ in front (Mods=\ProximityInventory). And the mod has to be made for Build 42.
Shall we set it up for you?
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Adding Workshop mods? Paste the links and Mod IDs into the Project Zomboid mod list tool: out come WorkshopItems= and Mods= with the Build 42 backslash.
Not sure whether your server is online? Check it in a second with the Project Zomboid server status checker: players, version and password, free.