A Windows desktop mod manager and game launcher for Warhammer 40,000: Space Marine 2, built by NK Forge.
Current release: v1.0.5
Download the latest installer from Nexus Mods.
The NK-Forge Space Marine 2 Mod Manager is designed to make switching between modded and vanilla play straightforward while keeping mod files, modded saves, and recovery snapshots organized.
- Detects Steam, Xbox / PC Game Pass, and Epic Games installations
- Dedicated Mods Vault for inactive mods
- Separate Mod Play Vault for modded save/config snapshots
- Toggle-based mod enabling and disabling
- Apply (no launch) workflow for preparing mods ahead of time
- Separate Mod Play and Vanilla Play launch paths
- Automatic save mirroring after tracked modded sessions
- Manual game-data save/mirroring on demand
- Watcher Activity panel for live file activity
- Configurable pre-reconcile backup retention
- Transactional backup creation so incomplete snapshots are never treated as valid backups
- About & Support panel with the installed application version
This tool is Windows-only.
| Platform | Status | Notes |
|---|---|---|
| Steam | Supported | Automatic install detection and Steam launch handling. |
| Xbox / PC Game Pass | Supported | Automatic detection and Xbox launch handling are included. |
| Epic Games | Experimental | Epic support is included, but remains less thoroughly field-tested than Steam/Xbox. |
If you use the Epic Games version and encounter a detection or launch issue, please include logs/screenshots when reporting it.
Pre-reconcile backups can be large, so v1.0.5 adds a user-controlled Backup Retention setting under Options.
- Select how many backups to keep: 1–10
- Default retention: 3
- Changing the setting takes effect after the next successful reconcile backup
- Older generated backups are pruned automatically
- Manual/unrelated folders are not removed by the retention cleanup
Default backup location:
%APPDATA%\nkforge_sm2_mod_manager\backups\pre-reconcile
Backups are created transactionally: data is copied into a temporary snapshot first and only promoted to a retained backup after the copy completes successfully. Failed or partial copies are not counted as valid recovery snapshots.
v1.0.5 also includes:
- Collision-safe backup naming for rapid/concurrent reconciles
- Compatibility with backup folders created by earlier releases
- Corrected permanent mod deletion behavior
- Deterministic manager-owned backup storage
- Narrower Electron IPC boundaries
- Renderer navigation protections and Content Security Policy hardening
- Safe configured-folder reveal actions
An optional About & Support section is available under Options. Supporting development is entirely optional and does not affect access to features, updates, or help.
Download the latest installer from Nexus Mods:
NK-Forge SM2 Mod Manager — Files
- Download the current Main File from Nexus Mods.
- Run the installer.
- If Windows displays a SmartScreen/security warning, choose More info → Run anyway if you trust the downloaded release.
- Launch the Mod Manager when installation completes.
The installer is not currently code-signed, so Windows may display an additional warning.
On first launch, the Setup Wizard attempts to detect the selected storefront installation and required paths, including:
- Space Marine 2 installation
- Save/config data
- Mods Vault
- Mod Play Vault
If a directory cannot be detected automatically, the wizard will allow you to select the appropriate location manually.
After setup, configured paths can be reviewed under Options → Managed Paths.
The Mods Vault stores installed mods that are not currently active in the game's mods directory.
Typical workflow:
- Extract/install a compatible mod into the Space Marine 2 mods directory or Mods Vault.
- Open or refresh the Mod Manager.
- Check a mod to make it active or uncheck it to return it to the vault.
- Click Apply (no launch) to reconcile the selected state.
The manager moves the managed mod entries between the active mods directory and Mods Vault as needed.
- Open the Mod Manager.
- Check the mods you want active.
- Uncheck mods you want stored in the vault.
- Click Apply (no launch) to reconcile the filesystem without launching the game.
A pre-reconcile recovery snapshot is created before the managed mod state is changed.
Open:
Options → Backup Retention
Use the slider to select 1–10 pre-reconcile backups to retain.
Because a snapshot can consume several gigabytes depending on your active mod set, choose a retention value appropriate for your available disk space.
The manager creates the newest backup first, confirms it completed successfully, and then removes older generated snapshots beyond the selected retention limit.
The Mod Manager keeps a separate Mod Play Vault for modded save/config snapshots.
Use Manual game data save to explicitly mirror the current tracked save/config data into the Mod Play Vault.
Important: If your most recent session was vanilla play, a manual save can mirror that current vanilla data into the Mod Play Vault. If you are unsure, make a copy of the Mod Play Vault before performing a manual mirror.
During a tracked modded launch:
- The manager restores the Mod Play Vault data for modded play.
- Space Marine 2 is launched through the detected storefront.
- The manager monitors the game session and relevant file activity.
- When the tracked game session ends, updated modded data is mirrored back to the Mod Play Vault.
Vanilla Play does not use the modded save-mirroring workflow.
- Enable the mods you want.
- Click Launch (Mod Play).
The manager reconciles the selected mod state, prepares mod-play data, launches the game through the configured storefront, and tracks the session for post-game mirroring.
- Disable the mods you do not want active.
- Click Launch (Vanilla Play).
Vanilla launch intentionally avoids the Mod Play Vault mirroring workflow.
The Watcher Activity panel provides visibility into manager-observed file activity, including mod and save/config events used by the application workflows.
The display can be cleared without deleting your files.
Default manager data is stored under Electron's application-data directory:
%APPDATA%\nkforge_sm2_mod_manager
Default locations include:
%APPDATA%\nkforge_sm2_mod_manager\mods_vault
%APPDATA%\nkforge_sm2_mod_manager\mod_play_vault
%APPDATA%\nkforge_sm2_mod_manager\backups\pre-reconcile
The exact configured paths can be viewed under Options → Managed Paths.
If you relocate a vault, existing backups in the old manager-data location are not automatically migrated.
- Confirm the mod is extracted into the expected Space Marine 2 mods directory or Mods Vault.
- Click Refresh if files were added while the manager was already running.
- Ensure the appropriate storefront client is running when required.
- Review detected/configured paths under Options → Managed Paths.
- Include the storefront (Steam, Xbox / PC Game Pass, or Epic) when reporting the problem.
Verify the corresponding configured path under Options → Managed Paths. The folder reveal actions only open manager-configured locations.
Open Options → Backup Retention and lower the retention value. The manager will prune older generated snapshots after the next successful reconcile backup.
Non-default or relocated installations may require manual path selection during setup.
- Complete setup and verify the detected storefront and paths.
- Add mods to the active mods directory or Mods Vault.
- Refresh the manager if files were added while it was running.
- Select mods and use Apply (no launch) to prepare the desired state.
- Use Launch (Mod Play) for a tracked modded session or Launch (Vanilla Play) for vanilla play.
- Leave the manager running during tracked Mod Play sessions so post-game mirroring can complete.
- Set Backup Retention based on the amount of disk space you want dedicated to recovery snapshots.
When reporting an issue, please include:
- Mod Manager version
- Storefront: Steam, Xbox / PC Game Pass, or Epic Games
- Windows version
- Description of what happened
- Relevant logs/screenshots when possible
- Nexus Mods:https://www.nexusmods.com/warhammer40000spacemarine2/mods/381?tab=files
- Discord:https://discord.gg/y8G8ptxjGu
- Email:dev@nkforge.com
- NK Forge:https://nkforge.com
- Ko-fi:https://ko-fi.com/nkforge
Install dependencies:
npm installRun the development environment:
npm run devType-check:
npm run type-checkBuild production assets:
npm run buildCreate the Windows installer/package:
npm run dist
npm startlaunches the built Electron main process directly and is not the normal Vite development workflow. Usenpm run devfor local development.
This project is licensed under the MIT License. See LICENSE for details.
Thank you for using the NK-Forge Space Marine 2 Mod Manager and for reporting issues as the project evolves. Community feedback directly helps improve reliability, compatibility, and the safety of the mod-management workflow.