This guide explains how to install Steam Workshop mods on your DayZ server hosted with Legion Hosting, including the difference between client-required and server-side-only mods, how to manage .bikey key files, and how signature verification works. For general server configuration, see the DayZ Server Setup Guide.
Finding Mod IDs on the Steam Workshop
Each mod on the Steam Workshop has a numeric Workshop ID visible in its page URL:
https://steamcommunity.com/sharedfiles/filedetails/?id=1559212036
The number at the end of the URL (e.g., 1559212036) is the Workshop ID. Collect the Workshop ID for every mod you want to install before continuing.
Adding Client-Required Mods
DayZ loads mods through the -mod= startup parameter. In GPanel, navigate to the Startup tab and locate the startup command or mod parameter field. Add your Workshop IDs using the following format:
-mod=@1559212036#;@1565871491#;@2291785593#
Each mod is prefixed with @ and separated by a semicolon. Append a # after each Workshop ID (e.g., @1559212036#). The trailing # tells the server to automatically download or update that mod from Steam Workshop every time the server starts, so your mods stay current without manual intervention. The server loads mods in the order they appear in this parameter.
-mod= list. Check each mod's Workshop page for load order requirements or listed dependencies. Incorrect load order is a common cause of server crashes on startup.
Server-Side-Only Mods
Mods that run only on the server and do not need to be installed by players (such as admin tools, logging mods, or server-side economy tweaks) should be added to the -serverMod= parameter instead of -mod=. In GPanel's Startup tab, locate the server mod parameter field and add Workshop IDs in the same @ID# format:
-serverMod=@2564972768#;@2672706716#
Players do not need to download or subscribe to mods listed in -serverMod=. Do not add client-required mods here -- use the main -mod= field for those.
Mod Key Files (.bikey)
DayZ uses a signature verification system to ensure clients and servers are running identical mod files. Each mod must have its .bikey file present in the server's keys/ directory, or players will be kicked with a signature mismatch error.
When mods are added using the @workshopID# format, the server automatically copies each mod's .bikey file into the keys/ directory when it downloads or updates the mod. In most cases you do not need to copy key files manually for Workshop mods.
Manual Key Installation (SFTP Uploads Only)
Manual key copying is only required when you upload a mod via SFTP rather than using the Workshop auto-download system:
- Navigate to the manually uploaded mod folder in the GPanel file manager or via SFTP.
- Inside the mod folder, look for a
keys/orKey/subdirectory containing one or more.bikeyfiles. - Copy those
.bikeyfiles into the server's rootkeys/directory. - Repeat for every manually uploaded mod. Missing key files will cause signature mismatch errors for connecting players.
keys/ subdirectory. If you do not see a keys/ folder, check the mod root for any .bikey file and copy it to the server's keys/ directory directly.
Signature Verification Settings
The verifySignatures setting in serverDZ.cfg controls how strictly the server enforces key checks:
| Value | Behaviour |
|---|---|
0 |
Disabled -- no signature verification. Do not use on public servers. |
1 |
Checks signatures but allows some unsigned content. |
2 |
Strict -- all mods must have valid keys in the keys/ directory. Recommended for public servers. |
Sharing Your Mod List with Players
Players must have the same client-required mods installed locally before they can connect to your server. To make this easier:
- Create a Steam Workshop Collection containing all your server's mods and share the collection link with your players.
- Alternatively, share the list of Workshop IDs so players can subscribe to each one individually.
- The DayZ Launcher will automatically enable matching mods when a player connects, but they must already be subscribed and downloaded.
Related Articles
- DayZ Server Setup Guide -- serverDZ.cfg configuration and how players connect
- DayZ Loot Economy (types.xml) -- customising item spawn rates and loot tables
- DayZ Troubleshooting -- common errors, BattlEye issues, and RCON setup
- How to Upload Files via SFTP