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Mods are where DayZ servers come alive — new weapons, base building, traders, whole new maps. DayZ mods come from the Steam Workshop and follow a simple pattern on the server: each mod is an @ModName folder, loaded through the -mod= startup parameter, and signed with a key the server must trust. This guide covers the full workflow.

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How DayZ Mods Work

Three pieces must line up for a modded server:
  1. The mod files — an @ModName folder in the server’s root directory (containing the mod’s addons/ PBOs).
  2. The load order — the -mod= startup parameter listing every mod, separated by semicolons.
  3. The signature key — each mod ships a .bikey file that must be copied into the server’s keys/ folder, because verifySignatures = 2 makes the server reject unsigned content.
And critically: every player must run the exact same mods (same versions) or they can’t join. The DZSA Launcher automates this on the client side.

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Installing a Mod

1

Get the mod files from the Workshop

Subscribe to the mod on the Steam Workshop using your own DayZ client. Steam downloads it to your PC — find it in steamapps/common/DayZ/!Workshop/@ModName (or steamapps/workshop/content/221100/<mod-id>).
2

Upload the @ModName folder to the server

Upload the entire @ModName folder to your server’s root directory (next to serverDZ.cfg) via SFTP — see File Management. Mods can be gigabytes, so SFTP beats the browser uploader here.
3

Copy the .bikey into keys/

Inside the mod folder you’ll find a keys/ (sometimes key/) subfolder containing one or more .bikey files. Copy each .bikey into the server’s keys/ folder. Skip this and every client gets kicked by signature verification.
4

Add the mod to the startup parameters

In the Game Panel, open your server’s Startup tab and add the mod to the -mod= parameter, semicolon-separated, no spaces:
-mod=@CF;@Community-Online-Tools
5

Restart and verify

Restart the server and watch the console. The mod list is printed during startup; errors about missing PBOs or keys show up here immediately.

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Load Order Matters

Mods load left to right, and frameworks must load before the mods that depend on them. @CF (Community Framework) is the classic example — it must come first: 
-mod=@CF;@Dabs Framework;@DayZ-Expansion-Core;@DayZ-Expansion;@Community-Online-Tools
Each mod’s Workshop page lists its dependencies — anything listed as required must be installed too, and placed earlier in the chain.
ModWhat it does
CF (Community Framework)The shared library huge numbers of mods depend on. Install it first, load it first.
Community Online Tools (COT)The standard in-game admin toolkit — teleport, item spawning, player management. See Admin Tools.
DayZ ExpansionA modular overhaul — vehicles including helicopters, base building, traders, quests, and a new map UI. Start with Core and add the modules you want.
Community maps like Namalsk and Deer Isle are installed the same way — they’re mods that also add a mission you reference in serverDZ.cfg (see Server Configuration).

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Updating Mods

When a mod updates on the Workshop, clients get the new version automatically — your server doesn’t. Until you update it, players are kicked for version mismatch.
1

Let Steam update your local copy

Launch Steam; subscribed mods update automatically in your local Workshop folder.
2

Re-upload the changed mod

Replace the server’s @ModName folder with the updated one via SFTP.
3

Refresh the key if it changed

Some updates ship a new .bikey. Copy any new key into the server’s keys/ folder (old keys can be removed once no mod uses them).
4

Restart

Restart the server. Done.
Take a backup before big mod updates — mods that add items interact with your economy files, and rolling back is much easier than untangling broken persistence.

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Common Errors

A mod’s .bikey is missing from the server’s keys/ folder. Check that every mod in -mod= has its key present, then restart.
Usually a wrong load order (dependency loaded after the mod that needs it) or a typo in -mod= — folder names must match exactly. Check the console output; it names the mod it choked on.
The player has a mod (or version) the server doesn’t. Point them at the DZSA Launcher, which syncs the exact mod set automatically.
Confirm the folder sits in the server root (not inside another folder), and that the name in -mod= matches the folder name character for character. On Linux-based servers, file name casing can matter — if a mod inexplicably fails to load, lowercase file names are a known fix; our support team can help.

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