A desktop app for building and exporting MoSimulator addressable mod groups.
Point it at your Unity project, tick the mods and platforms you want, and it
drives Unity headlessly to produce the finished .zip for each platform —
no command line, no hand-run build scripts.
| Operating system | Download |
|---|---|
| Windows | Mod Builder Installer Windows.msi |
| macOS (13 Ventura or newer) | Mod Builder Installer Mac.zip |
| Linux — Arch / CachyOS / Manjaro | Mod Builder Installer Linux.pacman |
| Linux — everything else | Mod Builder Installer Linux.AppImage |
These links always point at the newest release — they don't need updating when a new version ships. See all releases if you need an older version, and Install below for the per-OS setup steps (macOS and Windows both need one extra click to get past their security warnings).
You need two things installed already:
-
A MoSimulator Unity project — a clone of the public template (MoSimulator/MoSimulator-Public) or of MoSim-Reefscape-Public.
-
The Unity Editor version that project requires, installed through Unity Hub. The app reads the required version from your project and looks for a matching install — it won't install Unity for you.
If you plan to build for a platform you're not on (for example, the macOS zip from Windows), install that build support module for your Unity Editor in Unity Hub first.
You do not need to add anything to your Unity project by hand. The app
installs the Editor script it needs (Assets/Editor/AddressablesModExporter.cs)
automatically the first time it builds, and keeps it up to date afterwards.
Run the installer and follow the wizard (it lets you choose the install location and whether to create Start Menu / desktop shortcuts). It installs for your user only, so no administrator password is needed.
Windows SmartScreen will warn you that the publisher is unknown, because these builds aren't code-signed. Click More info → Run anyway.
Re-running the installer later brings up the standard Windows repair / uninstall / reinstall dialog.
Unzip it and drag V25 Mod Builder.app into your Applications folder.
The app isn't signed by a registered Apple developer, so the first launch is blocked. To get past it, right-click the app → Open, then click Open in the dialog. You only have to do this once.
If macOS refuses entirely (or moves the app to the Trash), restore it from the Trash, then run:
xattr -cr "/Applications/V25 Mod Builder.app"and try opening it again. As a last resort, open System Settings → Privacy & Security and look for an Open Anyway button near the bottom of the page right after the block happens.
Requires macOS 13 (Ventura) or newer.
On Arch, CachyOS, Manjaro and other pacman-based distros, use the
.pacman package — it installs and runs with no extra setup:
sudo pacman -U "Mod Builder Installer Linux.pacman"On any other distro, use the portable .AppImage. Make it executable
first, and note it needs libfuse2 present:
chmod +x "Mod Builder Installer Linux.AppImage"
./"Mod Builder Installer Linux.AppImage"The app walks you through three pages.
1. Select Unity Project. Pick the root folder of your MoSimulator Unity
project. The app reads the Unity version it needs and lists every Addressable
group in the project, skipping Unity's own default groups and the bundled
example mods (LynkMod, LynkModOfficial, MechTechMod). This is instant —
selecting a project never launches Unity. Your choice is remembered for next
time.
2. Unity Editor. The app finds your Unity Hub install of the required
version automatically. If it can't, click Browse for Unity Editor... and
point it at your Unity.exe (Windows), Unity.app bundle (macOS), or Unity
binary (Linux). This is remembered too.
3. Groups to build. Tick the mod group(s) you want. Each ticked group gets its own optional Version and Zip name override fields — use the zip name override if you want the released file named something other than the Addressable group name.
Click DETECT NEW MODS to list mod folders in your project that don't have
an Addressable group yet; they show up tagged NEW. Nothing is created just
by detecting them — a NEW mod only becomes a real Addressable group if you
tick it and build it, so mods you never build won't clutter your project.
4. Platforms. Windows, macOS and Linux are all ticked by default. Untick any you don't need for this run.
5. Build. The app launches Unity in the background, once per selected
platform, and streams the log so you can watch progress. Each platform gets a
full Addressables build (unavoidable — the bundle naming settings are
project-wide), and the app confirms the expected .zip actually landed in
Mods/ rather than just trusting Unity's exit code.
Unity can't open a project that's already open in the Editor. If yours is, the app offers to close that Editor for you — declining just cancels the build. It never touches Unity windows it didn't open itself.
If a platform fails, the run stops there and a RETRY button appears. Retry rebuilds only what didn't succeed — the platform that failed plus any that never got a turn. Platforms that already built keep their output and their zips, so fixing one platform doesn't cost you a rebuild of the others.
"Unity Editor not found." The required version probably isn't installed, or lives outside the default Unity Hub location. Install it via Unity Hub, or use Browse for Unity Editor... to point at it directly.
A build fails only for one platform. You're most likely missing that platform's build support module in Unity Hub. Add it to your Unity Editor install (Unity Hub → Installs → the gear icon → Add modules), then hit RETRY.
Where are my settings stored? Your last project, any manual Unity Editor path, and the output folder override are saved outside the app's install folder, so they survive reinstalls:
| OS | Location |
|---|---|
| Windows | %APPDATA%\v25-mod-builder\settings.json |
| macOS | app preferences (com.v25.modbuilder) |
| Linux | ~/.config/v25-mod-builder/settings.json |
If you used the older "MoSim Mod Builder" release, your settings are migrated automatically on first launch.
Where does the output go? Into Mods/<GroupName>/ inside your Unity
project, unless you set an output folder override.
Everything that builds this app lives in app/ — the Electron app
(Windows/Linux), the native macOS app, the bundled Unity Editor script, and
build/packaging instructions. See app/README.md if you want
to build it yourself or contribute.