Steam Input Plugin for Kerbal Space Program

Overview

This plugin extends Kerbal Space Program’s native Steam Input support by adding extra action sets and fixing maneuver mode detection, which broke in KSP 1.6. For background on the original issue, see KSP Issue #22165.

It also restores joystick (HID game controller) support, which stopped working reliably in the Steam build because of Squad’s built-in Steam Controller plugin. This mod disables that plugin and ships a replacement.

Features

The plugin adds several action groups:

• Compatible with Squad’s built-in Steam Input plugin for:
  • Menu — menus and UI
  • Flight — flight (including maneuver node mode)
  • Docking — docking
  • Editor — vehicle editor
• Map is split into three action groups:
  • MapFlight — map while using flight controls
  • MapDocking — map while using docking controls
  • MapEVA — map while in EVA
• Additional action groups:
  • Tracking Station — tracking station interface
  • Mission Builder — mission editor
  • Construction Mode — EVA construction with engineers
  • FreeIVA — FreeIVA mod

The settings lets you change the plugin’s log level for troubleshooting. The default is Info; set Debug or Trace for more detail in KSP.log.

To view logs in near real time, open the debug console (Alt+F12), go to Debug → Console, and enable Flush logs

System Requirements

• Linux or Windows 10 or later
• Steam client installed and running
• Kerbal Space Program 1.12 (Steam build)
• A Steam Input–compatible controller with back buttons (or equivalent), for the bundled layouts:
  • Steam Controller
  • Legacy Steam Controller
  • HORIPAD for Steam
  • Xbox Elite controller — use the default profile so Steam can use the paddles; install Xbox enhanced feature support from Steam (see Settings → Controller).
  • DualShock 4 / DualSense — only with extra rear inputs mapped (e.g. to stick clicks), or a model with back buttons; see Troubleshooting below.
  • Any other Steam Input–capable device — you can build your own layout in Steam’s configuration UI.

Installation

1. Configure Steam Input actions

1. Create a folder named controller_config in your Steam directory (e.g. C:\Program Files (x86)\Steam\controller_config).
   • A controller_base folder may already exist there; do not modify it.
2. Copy game_actions_220200_[your language].vdf into controller_config and rename it to game_actions_220200.vdf.

2. Install the plugin

Extract the plugin into GameData/SteamInput inside your KSP install.

3. Deploy the Steam VDF layout (optional)

You can either:

• Launch the game and bind everything in Steam’s controller UI, or
• Use one of the pre-built layouts shipped with the mod:
  • ksp_steaminput_steamcontroller_[language].vdf — Legacy Steam Controller
  • ksp_steaminput_steamcontroller_v2_[language].vdf — Steam Controller
  • ksp_steaminput_hori_[language].vdf — HORIPAD for Steam
  • ksp_steaminput_ps4_[language].vdf — PlayStation-style pads (see requirements above)
  • ksp_steaminput_xboxelite_[language].vdf — Xbox Elite (see requirements above)

Check that steam is NOT running, and place custom layouts in:

${SteamDir}/steamapps/common/Steam Controller Configs/[your SteamID]/config/220200/

Then, start Steam, and go to the controller settings of Kerbal Space Program. Under Your configurations, you should see the layouts you just added.

Usage

After installation, the plugin automatically activates the right action set for your current game context — the controller itself needs no extra setup.

To display the cheat sheet, click the toolbar icon. It shows the inputs of the configuration you have selected, so you first need to choose one in the main combo box:

• If you installed one of the pre-built layouts, you will find it in that list, under the name it was given during installation.
• If you built your own layout in Steam's controller UI, export it first through the Steam interface so it shows up in the list.

Because KSP ships with an old version of SteamInput, the mod cannot detect which configuration is currently active on your controller — that is why you select it yourself here.

Troubleshooting

If something goes wrong:

1. Steam is running and KSP is started from Steam.
2. VDF files are in the paths described above.
3. The plugin files are under GameData/SteamInput.
4. The controller is connected and visible to Steam.
5. Check KSP.log for lines prefixed with [SteamInput]; increase the log level in-game if needed.

Xbox Elite Controller

1. Install Xbox enhanced feature support: Steam → Settings → Controller → install next to that option.
2. Update the controller firmware if prompted.
3. No Xbox Accessories “slot” profile should override Steam: the LED under the Xbox button should be off when using the default Steam profile.

PS4 / PS5–style controllers

1. Standard DualShock 4 / DualSense pads have no rear buttons; the bundled PS4-style layout expects extra inputs (e.g. stick clicks used as back buttons).
2. Map those extra inputs as described in System Requirements.
3. You can always author a custom Steam Input configuration for your hardware.

Known issues

Separate VDF files are provided per language even though VDF can carry localization; getting Steam’s localization path to work reliably is still TODO — contributions welcome.

On Linux, non–US English keyboard layouts (e.g. non-QWERTY) may cause issues; see this report.

Support

Issues, feature requests, and contributions: GitHub repository.

Building from source

Clone with submodules

The shared UI code lives in the KSP-Shared submodule and is compiled directly into the plugin, so its sources must be present before building. Clone recursively:

git clone --recurse-submodules https://github.com/lhervier/KSP-SteamInputPlugin.git

If you already cloned without --recurse-submodules, initialize the submodules afterwards:

git submodule update --init --recursive

Build

TODO

• Windows / Linux

• VS Code

• .NET / target framework (e.g. .NET Framework 4.7)

• Node.js (for VDF merge scripts)

• build.bat — build release outputs into the Release folder

• install.bat — deploy built files

License

This project is licensed under the MIT License — see the LICENSE file for details.