DV Mod Manager

Desktop mod manager for Derail Valley, built with Avalonia UI and .NET 8.

DV Mod Manager scans your Mods and Mods.inactive folders, lets you quickly activate/deactivate mods, and provides profile, update, backup, and rollback workflows.

Highlights

• Cross-platform desktop app (Avalonia) targeting .NET 8.
• Auto-detects Derail Valley install path (Steam on Windows and Linux).
• Scans and watches Mods and Mods.inactive for changes.
• Install mods from .zip archives (expects Info.json).
• Create and manage custom mod groups in the Available and Active lists.
• One-click activate/deactivate for single mods or grouped mods.
• Multi-select mods with checkboxes or CTRL+click; activate/deactivate all checked mods at once.
• Click a group header to select all mods in that group; CTRL+click to append/toggle.
• Drag one or multiple selected mods between groups.
• Automatically activates inactive required dependencies when enabling a mod (when available locally).
• Update checks via:
  • GitHub releases (if defined in the Info.json).
  • Nexus Mods API (when API key is configured).
• Bulk update for downloadable GitHub updates.
• Version archive cache with rollback support.
• Profile system to save/apply mod states.
• Import/export profiles as JSON or as self-contained ZIP modpacks.
• Optional automatic backup before bulk changes.
• Safety lock while Derail Valley is running.

Supported Mod Metadata

This app reads Unity Mod Manager style Info.json metadata.

Important fields include:

• Id
• DisplayName
• Version
• Author
• Requirements
• Repository
• HomePage

If Info.json is missing or invalid, the mod folder can still be shown, but with limited metadata.

Requirements

• .NET SDK 8.0+
• Derail Valley installed (Steam)
• Windows or Linux

Getting Started

For most users, setup is just downloading a release build:

1. Open the GitHub Releases page for this repository.
2. Download the zip for your OS (win-x64 or linux-x64).
3. Extract and run DVModManager.

On first launch, the app will:

1. Load settings from your user profile.
2. Try to auto-detect the game path.
3. Ask for a game folder if detection fails.

App Data Locations

Settings and runtime data are stored under:

• %APPDATA%/DVModManager on Windows
• $HOME/.config-based locations depending on platform runtime behavior

Key paths used by the app:

• settings.json
• logs/
• downloads/
• versions/
• profiles/
• backups/

How Mod State Works

• Active mods live in <GamePath>/Mods
• Inactive mods live in <GamePath>/Mods.inactive
• Activating/deactivating a mod moves its folder between these directories.

For updates and rollbacks, current versions are archived to the local version cache before replacement/removal when applicable.

Profiles

Profiles store desired mod active/inactive state and version targets.

You can:

• Save current setup as a profile
• Apply a saved profile
• Import/export profiles as JSON
• Export a profile as a self-contained ZIP modpack (bundles all mod files alongside the profile)
• Import a modpack ZIP via the Install button — the app shows the full mod list and a security warning before importing; profile names are deduplicated automatically
• Delete profiles you no longer need

Applying a profile can trigger:

• Activations/deactivations
• Version rollbacks (if required and available)
• Download missing mods (if Repository is defined in Info.json)

Redistribution note: When exporting a ZIP modpack the app reminds you that most mods do not permit redistribution on third-party sites. Share modpack ZIPs only within the limits of each mod's licence.

Security note: ZIP modpacks contain the actual mod binaries. Only import modpacks from sources you trust.

In-game profile associations

The optional DVModProfiles mod adds a "Mod Profile" row to Derail Valley's save menu, listing the profiles this app has saved under profiles/ and letting you tag each save with the one it belongs to. When you load a save whose profile isn't the one the app last applied, the mod warns you and offers to quit so you can switch profiles in the app to the correct one.

The in-game menu also allows you to optionally associate UMM mod settings with a profile, so that the correct settings for a mod will be applied when it is loaded.

Steam Cloud sync

With the mod installed and its Steam Cloud setting on, your profiles/ files are mirrored into Derail Valley's cloud quota and merged onto your other machines. Steam synchronizes the files whenever the the game starts or quits.

Updates

• Check Updates scans all detected mods.
• GitHub updates with direct downloadable assets can be installed in-app.
• Nexus updates (and non-direct-download cases) open the mod page for manual download/install.

Optional credentials in Settings:

• GitHub token (to improve API rate limits. Only needed for mass downloading mods < 60/h)
• Nexus API key

Logging and Error Handling

• File logs are written to the app logs directory.
• Unhandled exceptions are captured and logged.
• The UI status bar reports operational feedback.

Repository Structure

This repository contains both a desktop app (DVModManager) and an in-game supporting mod (DVModProfiles).

DVModManager.slnx
DVModManager/
  Models/
  Services/
  ViewModels/
  Views/
  Converters/
  Assets/
DVModProfiles/
  DVModProfiles.slnx
  DVModProfiles.csproj
  Profiles/
  UI/
  info.json
  repository.json
  package.ps1
  deploy-debug.ps1

The two are deliberately kept in separate solutions. DVModProfiles compiles against Derail Valley's shipped assemblies, so it cannot be built without the game installed. See DVModProfiles/README.md for the mod's reference setup, packaging, and release process.

Contributing

Issues and pull requests are welcome.

Branching and PR policy

• Please branch from beta and open PRs targeting beta.
• The beta branch is the most up-to-date integration branch.
• PRs should only be merged after the beta branch build pipeline is passing.

Developer setup

Requirements:

• .NET SDK 8.0+
• Derail Valley install for local testing

Build and run the manager from repository root:

dotnet restore
dotnet build DVModManager/DVModManager.csproj
dotnet run --project DVModManager/DVModManager.csproj

Building the in-game mod additionally requires Derail Valley installed and a DVModProfiles/Directory.Build.targets pointing at the game's Managed folder (see DVModProfiles/README.md). It is not part of the manager's solution, so build it explicitly:

dotnet build DVModProfiles/DVModProfiles.csproj -c Release

Publishing (for maintainers/contributors)

The project is configured for self-contained single-file publish.

CI/CD release automation:

• The release workflow runs on pushed tags matching v*.
• Tags created from main or beta will trigger automatic release packaging and GitHub Release creation.
• If the tag name contains -beta, the created GitHub Release is marked as draft/prerelease.

Windows x64:

dotnet publish DVModManager/DVModManager.csproj -c Release -r win-x64

Linux x64:

dotnet publish DVModManager/DVModManager.csproj -c Release -r linux-x64

Contribution notes

• Keep behavior safe around file operations.
• Preserve rollback/backup guarantees.
• Test with both active and inactive mod layouts.

License

MIT - see LICENSE