KSP2 Redux Updater

This is the installer, updater and uninstaller application for KSP2 Redux.

macOS

KSP2 never shipped for the Mac, so the macOS launcher (Ksp2Redux-macos-arm64.dmg, Apple Silicon) carries a Wine runtime that runs the Windows game, and can download your copy of KSP2 from Steam.

The launcher is not signed by Apple yet, so macOS asks you to approve it the first time:

1. Open the .dmg and drag KSP2 Redux into Applications.
2. Open KSP2 Redux. When macOS says it could not verify the app, click Done.
3. Open System Settings, go to Privacy & Security, and scroll down to Security. Next to the message about KSP2 Redux, click Open Anyway, then confirm with your password or Touch ID.
4. Click Open Anyway once more when macOS asks. From then on the launcher opens normally, until you download a new version.

If the launcher opens but the game does not start, run this once in Terminal, then try again:

xattr -dr com.apple.quarantine "/Applications/KSP2 Redux.app"

Command line

redux-launcher-cli drives the same install path as the launcher window, from a terminal. It reads and writes the same configuration, so the two stay in step.

Install it with one line. Nothing needs administrator rights.

irm https://raw.githubusercontent.com/KSP2Redux/Updater/main/scripts/install-cli.ps1 | iex

curl -fsSL https://raw.githubusercontent.com/KSP2Redux/Updater/main/scripts/install-cli.sh | bash

That drops the binary in %LOCALAPPDATA%\Programs\redux-launcher-cli or ~/.local/bin and puts it on your PATH. On a Mac the same curl line installs the Apple Silicon build, and the macOS launcher app also carries a copy at KSP2 Redux.app/Contents/MacOS/redux-launcher-cli. Running it again upgrades in place. Then:

redux-launcher-cli --help              # every command, with examples
redux-launcher-cli detect              # find KSP2 the way the launcher does
redux-launcher-cli installs add        # add the install it found to the config
redux-launcher-cli update              # install the newest build in its channel
redux-launcher-cli launch              # start the game

No KSP2 on this machine, or on a Mac, where Steam will not download it? The CLI can fetch your own copy with your Steam account, no Steam client needed:

redux-launcher-cli steam login         # scan a QR code with the Steam Mobile App, or --password
redux-launcher-cli steam download      # download KSP2 into ~/Games and add it as the active profile
redux-launcher-cli update              # then install Redux into it

The sign-in is shared with the launcher window. On macOS, launch runs the game through the Wine runtime inside the launcher app (or CrossOver when that is all there is), in the same prefix the launcher uses, so saves are shared too. kill stops it.

Everything in the launcher's Settings tab is here too. Each install profile carries its own launch settings: installs show lists them, installs set changes them (including launching through Steam on Windows and Linux), and installs delete removes a copy of the game from disk along with its profile. settings shows and changes the patch source, concurrent chunks and verbose logging, open install|logs|game-data|storage opens those folders, and news lists the latest posts.

It keeps itself current: redux-launcher-cli self-update installs the newest build, version --check reports whether one is published, and the CLI mentions a new release on its own once a day when you are running it in a terminal. --no-update-check turns that off, self-uninstall removes the binary and leaves your launcher config alone.

For scripting, --json puts a document on stdout and everything else on stderr, exit codes are stable, and completion pwsh|bash prints a shell completion script.

Development

Requires the .NET 10 SDK (pinned in global.json).

dotnet build          # build everything
dotnet test           # run the test suite

The launcher also runs on macOS for development (the game itself is not available there yet). To produce a proper .app bundle:

dotnet msbuild src/Ksp2Redux.Tools.Launcher/Ksp2Redux.Tools.Launcher.csproj \
  -t:BundleApp -p:RuntimeIdentifier=osx-arm64 -p:Configuration=Release \
  -p:SelfContained=true -p:PublishSingleFile=false

The solution (Ksp2Redux.Tools.slnx) is laid out as:

Path	What it is
src/Ksp2Redux.Tools.Launcher	The Avalonia launcher/updater app (the main deliverable)
src/Ksp2Redux.Tools.Cli	Headless CLI over the launcher's install path (redux-launcher-cli)
src/Ksp2Redux.Tools.Common	Shared patch engine (Patching/) and release-feed schema (Models/)
src/Ksp2Redux.Tools.Installer	Windows WPF installer
src/Ksp2Redux.Tools.PatchApplier / PatchGenerator	CLI tools to apply/create patch files
src/Ksp2Redux.Tools.Uploader	CLI tool that publishes releases and the manifest
tests/	NUnit test suite (incl. Avalonia headless UI tests) and the MockGame fixture
design/	The @ksp2redux/design web design system, previews, and conventions

Package versions are managed centrally in Directory.Packages.props; shared MSBuild settings (including the version) live in Directory.Build.props. Warnings are errors.

Releasing

Bump <Version> in Directory.Build.props and merge to main. CI detects the new version, tags updater-v<version>, and publishes one release holding both products (see .github/workflows/release.yaml):

Asset	What it is
Ksp2Redux-win-x64.exe, Ksp2Redux-linux-x64	the launcher
Ksp2Redux-macos-arm64.dmg	the macOS launcher, with the Wine runtime and the CLI inside
redux-cli-x64.exe, redux-cli-x64, redux-cli-macos-arm64	the command line tool

The CLI asset names must never contain win or linux. The launcher's self-update picks its download out of this same asset list with Assets.FirstOrDefault(a => a.Name.Contains("win" or "linux")), and launchers already installed cannot be fixed, so an asset that matched would be handed to them as an update to themselves. Note windows contains win, and so does darwin, so the rule is about the substring. A test in CliReleaseServiceTest holds the CLI to it.

The release notes lead with a table saying which file is which, because a single page with four binaries on it is how people end up downloading the command line tool when they wanted the launcher.

Publishing to winget is a separate manual step, see packaging/winget.

It is a cross-platform application with releases currently being made for Windows and Linux (untested). Please report any problems with running the application in Issues or in the KSP2 Redux Discord server.

KSP2 Redux

For more information about KSP2 Redux, see our website or the Redux GitHub page.

Contact

You can contact us in the KSP2 Redux Discord server.