How to Add Mods to Your Kerbal Space Program Server

In Kerbal Space Program mods only run inside the game itself – the DarkMultiPlayer server does not load any KSP mods. Its job is a different one: through the file mod-control.txt it defines which mods players are allowed to use, and it can optionally distribute a ready-made modpack to them.

Important

All players need the same mods locally in their GameData folder. If a player is missing a mod from the server list or has an additional one installed, the connection is rejected.

Warning

Create a backup before changing the mod list. Vessels built with parts from a mod stop working as soon as that mod is removed.

Generate and upload the mod list

You do not write the mod list by hand – you generate it in the game: the DMP client reads your GameData folder and writes the finished file from it.

1. Set up KSP with the mods you want
   Install all mods that should be allowed on the server on your PC and start Kerbal Space Program.

2. Open Mod Control
   In the DMP window in the main menu click on Options and switch to the Advanced tab. It contains the Mod Control section.

3. Generate the file
   In the Mod Control section click on Whitelist or Blacklist. The file is written directly into your KSP folder:

   [KSP folder]/mod-control.txt

4. Stop the server
   Stop your server via the dashboard. The mod list is only read on server start.

5. Connect via SFTP
   Connect to your server via SFTP.

6. Upload the file
   Upload the file into the following directory and replace the existing one:

   /Config/mod-control.txt

7. Start the server
   Start your server. From now on it checks the GameData folder of every joining player against this list.

Whitelist or blacklist?

Variant	Meaning
Whitelist	Only the mods from your installation are allowed. The usual choice for a server with a fixed mod list.
Blacklist	Players may use any mods. Only explicitly blocked files and resources are forbidden.

Note

If the file is missing, your server automatically generates a mod-control.txt on startup that only contains the stock parts of the game. If an old file is still present at that point, it is renamed to mod-control.txt.bak first. This does not happen when you upload the file via SFTP – there you overwrite the file yourself, so keep a copy beforehand.

Structure of mod-control.txt

The file consists of sections, each starting with a !. Lines starting with # are comments.

Section	Meaning
!required-files	Files every player must have installed
!optional-files	Files that may be installed but are not required
!partslist	All parts that may be used on the server
!resource-whitelist	Only the listed files are allowed (whitelist variant)
!resource-blacklist	The listed files are forbidden (blacklist variant)

Entries are written as a path relative to the GameData folder, optionally followed by a checksum:

DarkMultiPlayer/Plugins/DarkMultiPlayer.dll=6a1c9a...

Warning

!resource-whitelist and !resource-blacklist are mutually exclusive. Only one of the two sections may contain entries.

Configure mod control

How strictly your server checks is controlled by the value modControl in the file /Config/Settings.txt. Stop your server before editing the file.

Value	Meaning
ENABLED_STOP_INVALID_PART_SYNC	Default. Vessels using forbidden parts are not synchronized to the other players.
ENABLED_STOP_INVALID_PART_LAUNCH	Vessels using forbidden parts cannot be launched at all.
DISABLED	No checks. Every player can use any mods.

Important

Only disable mod control if you know what you are doing. Without checks, vessels with parts other players cannot load end up in the universe.

Distribute a modpack to your players

Optionally your server can provide the matching mods to your players so nobody has to collect them one by one.

1. Choose the mode
   Open the dashboard, go to the settings and set the field Mod Pack Mode:

   Value	Meaning
   NONE	Default. The server does not distribute any mods.
   CKAN	The server sends a CKAN file containing the mod list to the players.
   GAMEDATA	The server sends the complete mod files to the players.

2. Upload the modpack
   Upload the mods via SFTP into the matching location:

   /Config/GameData/            (for GAMEDATA)
   /Config/DarkMultiPlayer.ckan (for CKAN)

   Tip

   Alternatively an admin can upload their complete GameData straight from the game: the command /upload in the DMP chat is enough. Without admin rights the message "You are not an admin, unable to upload" appears – see Add Admin.

3. Refresh the file list
   If you uploaded the files via SFTP, run the following command in the console of your dashboard afterwards:

   /reloadmods

   Note

   Without this command, players report the message "DMP Server has an out of date hash list. Tell the admin to run /reloadmods".

4. Inform your players
   To install the pack, players need the additional tool DMP Modpack Updater from d-mp.org/downloads. Kerbal Space Program has to be closed for that – the GameData folder cannot be modified while the game is running.

Warning

The values Mod Pack Mode, Warp Mode, Game Mode, Game Difficulty and Server Name are written from the dashboard into Settings.txt on every server start. Only change them in the dashboard – changes made directly in the file are overwritten on the next start.

Note

Distributing a modpack does not replace the mod-control.txt. It only makes sure players get the files – the actual checking still happens through the mod list.