gregWiki/docs/tools/workshop-uploader.md

title, sidebar_label, description

title	sidebar_label	description
WorkshopManager	WorkshopManager	Windows desktop app for managing Steam Workshop content, browsing mods, and publishing for Data Center (FrikaMF).

WorkshopManager

WorkshopManager is a .NET MAUI desktop app for Windows that serves as a full-featured Steam Workshop client for Data Center. It combines content authoring (publish/update), a Mod Store for browsing and installing community mods, and a Mod Manager for dependency health checks.

Features

Author tools (Projects / Editor / My Uploads)

• Create workshop projects from templates (vanilla assets, MelonLoader mods, FMF plugins).
• Edit title, description (with BBCode toolbar), visibility, tags, and preview image; stored in metadata.json.
• BBCode formatting toolbar — insert Steam-compatible formatting (bold, italic, headings, URL, image, list, code, quote, spoiler, horizontal rule, table) directly in the description editor.
• Save and upload to Steam — saves metadata, publishes content/ to Steam Workshop, then syncs your local folder with Steam's version (like a git pull after push).
• Image sync — after publishing, the preview image and gallery screenshots are re-downloaded from Steam so your local project always matches what's live.
• Additional screenshots — attach up to 9 gallery images that appear on the Steam Workshop page alongside the main preview.
• Change notes — required for the first publish, recommended for updates; shown on the Workshop changelog tab.
• Upload readiness check — validates title, description, content folder, preview image, tags, content size, and changelog before allowing upload.
• View on Steam — open your published item in the browser.
• Export content as ZIP — create a distributable archive of the content folder.
• Pagination across all list views (My Uploads, Browse, Subscribed, Favorites).
• Per-item stats — subscriptions, votes, score, size.

Mod Store (integrated in Mod Manager)

• Browse all Workshop items for Data Center with tag filtering and sort options (last updated, newest, top rated, trending, most subscribed, title A-Z).
• Search mods by text.
• Subscribe / Unsubscribe to mods directly from the store.
• Favorites — bookmark mods for quick access.
• Vote (up/down) on workshop items.
• Item detail view — full statistics, description, tags, gallery images, action buttons, and links to changelog/comments.

Mod Manager / Health

• Dependency health checks: game installed, MelonLoader, Il2Cpp assemblies, FMF core, FMF plugins directory, ModCfg directory.
• MelonLoader download page link and game folder access.
• FMF Plugin channels — stable (local scan) and beta (server, TODO).

Settings

• Workspace path — change where projects are stored (defaults to <GameRoot>/workshop).
• Language — switch between EN, DE, RU, ES, IT, JP, PL, CN (defaults to system language). Restart button applies the change instantly.
• Mod Store toggle — enable/disable the Mod Store tab (disabled by default). Restart button included.
• Community links — quick access to Discord, Modding Channel, and GregFramework.eu.

FMF dependency notice

• Projects can be marked as "Needs FrikaModFramework" in the editor. When uploading, a notice is automatically appended to the Steam description telling users to install FMF.

Requirements

• Windows 10 (version 1809+).
• Steam with a signed-in account that owns Data Center (App ID 4170200).
• No additional dependencies — the release is fully self-contained (includes .NET runtime and Windows App SDK).
• steam_appid.txt must be next to the executable (included in the release build). The app loads steam_api64.dll from Data Center_Data/Plugins/x86_64/ in the Data Center install when possible; otherwise it uses the copy shipped next to the uploader.

Paths and directories

Workspace path (your authoring projects)

The workspace is resolved from Steam: <Data Center install>/workshop.

Fallback (no Steam): %USERPROFILE%\DataCenterWS.

You can change this in Settings → Workspace path.

On first launch the app creates the structure and places a sample metadata.sample.json under .templates/.

Where Steam installs subscribed Workshop mods

When a user subscribes to a Workshop item, Steam downloads it to:

<SteamLibrary>\steamapps\workshop\content\4170200\<PublishedFileId>\

For example, if Steam is installed in the default location and the item ID is 123456789:

C:\Program Files (x86)\Steam\steamapps\workshop\content\4170200\123456789\

If you have multiple Steam library folders (e.g. on a different drive), the path follows that library's location:

D:\SteamLibrary\steamapps\workshop\content\4170200\123456789\

The game reads from this folder at startup. The exact path per item can be inspected in the Steamworks API via ugc.Directory after calling DownloadAsync.

:::info Finding your Steam library folder Open Steam → Settings → Storage to see all configured library folders and which drive each uses. :::

Where the game is installed

The game install directory is typically:

C:\Program Files (x86)\Steam\steamapps\common\Data Center\

The app resolves this automatically via SteamApps.AppInstallDir(4170200).

Native mod format (config.json)

Data Center has a built-in mod system (ModLoader) that loads mods from config.json files. This is the "vanilla" modding approach — no MelonLoader or FMF required.

How the ModLoader works (internal flow)

The game's ModLoader (a Unity MonoBehaviour) runs the following on startup:

1. SyncWorkshopThenLoadAll() — a coroutine that:
   • Queries all subscribed Steam Workshop items (PublishedFileId_t[])
   • Waits for downloads to complete (with timeout)
   • Copies each Workshop item folder into StreamingAssets/Mods/workshop_<ID> via CopyDirectory()
2. LoadAllMods() — scans all subdirectories in the mods path:
   • Calls LoadModPack(folderPath) for each mod folder
   • Reads config.json, then for each entry calls:
     • LoadShopItem() → CreateShopTemplate() + CreateShopButton() for purchasable items
     • LoadStaticItem() → CreateStaticInstance() for fixed-position decorations

:::warning DLL loading timing The LoadDll() method exists in the ModLoader but object assets (shopItems, staticItems) are loaded at game startup. DLL-based mods (dlls[] in config.json) are loaded later at SaveLoad runtime, not during the initial LoadAllMods pass. This means DLL plugins are not available until a save is loaded. :::

Internal state tracked by ModLoader:

• modTemplates — Dictionary<int, GameObject> of loaded shop item prefabs by mod ID
• modTemplatesByFolder — Dictionary<string, GameObject> of prefabs by folder name
• staticInstances — List<GameObject> of instantiated static decorations
• loadedPlugins — List<IModPlugin> of loaded DLL plugins
• nextModID — auto-incrementing ID counter

Mod location (manual install)

Mods are placed under the game's streaming assets:

Data Center_Data\StreamingAssets\Mods\<mod_folder>\

Each mod has its own folder with a config.json and its asset files.

Mod location (Workshop subscribers)

When delivered via Steam Workshop, the game's ModLoader.SyncWorkshopThenLoadAll() automatically copies subscribed item content from the Workshop download folder into StreamingAssets/Mods/workshop_<ID>:

steamapps\workshop\content\4170200\<PublishedFileId>\
  →  copied to  →
Data Center_Data\StreamingAssets\Mods\workshop_<PublishedFileId>\

The workshop_ prefix distinguishes Workshop-downloaded mods from manually installed ones.

config.json reference

{
  "modName": "My Cool Mod",
  "shopItems": [
    {
      "itemName": "Custom Server",
      "price": 500,
      "xpToUnlock": 0,
      "sizeInU": 2,
      "mass": 5.0,
      "modelScale": 1.0,
      "colliderSize": [0.5, 0.5, 0.5],
      "colliderCenter": [0.0, 0.0, 0.0],
      "modelFile": "server.obj",
      "textureFile": "server.png",
      "iconFile": "server_icon.png",
      "objectType": 0
    }
  ],
  "staticItems": [
    {
      "itemName": "Wall Poster",
      "modelFile": "poster.obj",
      "textureFile": "poster.png",
      "modelScale": 1.0,
      "colliderSize": [0.5, 0.5, 0.05],
      "colliderCenter": [0.0, 0.0, 0.0],
      "position": [2.0, 1.5, -3.0],
      "rotation": [0.0, 90.0, 0.0]
    }
  ],
  "dlls": [
    {
      "fileName": "MyModPlugin.dll",
      "entryClass": "MyModPlugin.Plugin"
    }
  ]
}

config.json fields

Field	Description
modName	Display name of the mod
shopItems[]	Purchasable objects that appear in the in-game shop
staticItems[]	Decorations placed at fixed world positions
dlls[]	Native plugin DLLs (see DLL mods without MelonLoader)

shopItems fields

Field	Type	Description
itemName	string	Display name in the shop
price	int	Purchase price
xpToUnlock	int	XP threshold to unlock (0 = immediately available)
sizeInU	int	Rack unit size of the object
mass	float	Object mass
modelScale	float	Scale multiplier for the 3D model
colliderSize	[x, y, z]	Physics collider dimensions
colliderCenter	[x, y, z]	Physics collider offset
modelFile	string	Path to .obj model file (loaded via LoadMesh)
textureFile	string	Path to .png texture file (loaded via CreateMaterial)
iconFile	string	Path to .png shop icon (loaded via LoadIcon)
objectType	int	0 = passive object

The ModShopItem UI component displays each shop item with itemIcon, txtName, and txtPrice. Purchasing calls ButtonBuyItem().

staticItems fields

Field	Type	Description
itemName	string	Display name
modelFile	string	Path to .obj model file
textureFile	string	Path to .png texture file
modelScale	float	Scale multiplier
colliderSize	[x, y, z]	Physics collider dimensions
colliderCenter	[x, y, z]	Physics collider offset
position	[x, y, z]	World position
rotation	[x, y, z]	Euler rotation in degrees

Asset loading pipeline

Method	Input	Output
LoadMesh(folderPath, modelFile)	.obj file	Unity Mesh
CreateMaterial(folderPath, textureFile)	.png file	Unity Material
LoadIcon(folderPath, iconFile)	.png file	Unity Sprite
LoadTexture(path)	.png file	Unity Texture2D

• 3D models: Wavefront OBJ format (.obj)
• Textures: PNG format (.png)
• Icons: PNG format (.png) — shown in the shop UI
• All asset file paths in config.json are relative to the mod folder

DLL mods without MelonLoader

The game's ModLoader has built-in DLL loading — no MelonLoader required. This is done via the dlls array in config.json:

{
  "modName": "My Plugin Mod",
  "shopItems": [],
  "staticItems": [],
  "dlls": [
    {
      "fileName": "MyPlugin.dll",
      "entryClass": "MyPlugin.Plugin"
    }
  ]
}

How it works internally:

1. ModLoader.LoadDll(folderPath, DllEntry) loads the DLL from the mod folder
2. The entryClass must reference a class that implements the IModPlugin interface
3. Loaded plugins are stored in ModLoader.loadedPlugins (List<IModPlugin>)

:::warning Loading timing Unlike asset objects (shopItems, staticItems) which are loaded at game startup, DLL mods are loaded at SaveLoad runtime — i.e., when a save file is loaded, not when the game first starts. Your IModPlugin will not be instantiated until the player enters a save. :::

DLL entry requirements:

Field	Description
fileName	The .dll file in the mod folder
entryClass	Fully qualified class name (e.g. MyNamespace.MyPlugin) that implements IModPlugin

:::caution Experimental feature The developer has marked DLL loading as untested. The LoadDll method and IModPlugin interface exist in the game code, but stability is not guaranteed. A mod that uses only shopItems and staticItems (asset-only) is the safest approach. :::

Advantages over MelonLoader:

• No external framework needed — works with the vanilla game
• Distributed via Workshop like any other mod (just include the DLL in the mod folder)
• The game manages loading/unloading through its own lifecycle

Limitations:

• The IModPlugin interface contract is not publicly documented — you need to reference the game's IL2CPP assemblies to implement it
• Less flexibility than MelonLoader's Harmony patching
• Only the entry class specified in entryClass is instantiated
• DLLs are loaded at SaveLoad time, not at game startup — no early initialization possible

:::note Current limitations For now, only passive objects are supported for shop items (objectType: 0). Active/functional item types may be added in future game updates. :::

ModPathRedirector — Workshop download at MelonLoader init

Release & download: FMF.ModPathRedirector Release — installation steps and GitHub download (FMF.ModPathRedirector.dll).

The game loads native mods from Data Center_Data\StreamingAssets\Mods\. Workshop items are copied into subfolders named workshop_<PublishedFileId> under that path (see Steam install path).

ModPathRedirector is a MelonLoader plugin (not a MelonMod): install the DLL under {GameRoot}/Plugins/. It does not change native mod paths. It calls steam_api64.dll directly (Steam flat API: SteamAPI_ISteamUGC_*). The game ships this DLL under Data Center_Data/Plugins/x86_64/; the plugin loads it from there first, then falls back next to the executable. After the Il2Cpp assembly step (see MelonLoader log: Il2CppAssemblyGenerator), OnPreModsLoaded blocks loading MelonMods until each subscribed Workshop item reports installed in Steam and a matching Data Center_Data/StreamingAssets/Mods/workshop_<ID>/ folder exists (per-item DownloadItem, SteamAPI_RunCallbacks, timeouts). If the game has not copied Workshop content into StreamingAssets/Mods yet, the plugin continues after a short grace period and logs a warning — restart once if mods are missing.

What it does:

• On each frame (from OnApplicationStarted), waits for SteamAPI_IsSteamRunning and resolves SteamAPI_SteamUGC_v0xx → ISteamUGC*, then calls the native UGC APIs (no Il2Cpp Steamworks wrapper)
• Leaves ModLoader.LoadAllMods / CopyDirectory unchanged — Workshop sync still uses Data Center_Data/StreamingAssets/Mods/workshop_<ID>/

Installation:

1. Copy FMF.ModPathRedirector.dll into <GameRoot>/Plugins/ (MelonLoader Plugins folder next to the executable)
2. Start the game — subscribed Workshop content is requested early; manual native mods still go under Data Center_Data/StreamingAssets/Mods/<folder>/ (each folder with a config.json)

Layout (unchanged from vanilla):

Data Center/
  Data Center_Data/
    Plugins/
      x86_64/
        steam_api64.dll          ← shipped with the game (Steam API; ModPathRedirector loads this)
    StreamingAssets/
      Mods/
        my_cool_mod/             ← manual native mod
          config.json
        workshop_12345678/       ← Workshop item (game copies here after download)
          ...
  Plugins/                       ← MelonLoader plugins (FMF.ModPathRedirector.dll)
  Mods/                          ← MelonLoader mods (other FMF.* MelonMods)
  Data Center.exe

Project layout

For each Workshop project:

1. Create a folder under the workspace (the folder name appears in the list).
2. Add a content/ subfolder with files to ship:
   • For vanilla mods: config.json + .obj models + .png textures directly in content/
   • For MelonLoader mods: content/Mods/ with .dll files
   • For FMF plugins: content/FMF/Plugins/ with .dll files
3. Optionally create metadata.json yourself or fill it in the app.
4. Optionally add preview.png (or .jpg, .jpeg, .gif, .webp) at the project root.
5. Optionally add gallery screenshots under screenshots/ — these are uploaded as additional preview images.

Example: Vanilla mod (native config.json)

workshop/
└── MyCustomServers/
    ├── metadata.json              # Workshop metadata (title, desc, tags)
    ├── preview.png                # Main preview image
    └── content/                   # Shipped to subscribers
        ├── config.json            # Native mod definition
        ├── server.obj             # 3D model
        ├── server.png             # Texture
        └── server_icon.png        # Shop icon

Example: MelonLoader mod

workshop/
└── MyMelonMod/
    ├── metadata.json
    ├── preview.png
    └── content/
        └── Mods/
            └── MyMod.dll

Example: FMF plugin

workshop/
└── MyFmfPlugin/
    ├── metadata.json
    ├── preview.png
    └── content/
        └── FMF/
            └── Plugins/
                └── FFM.Plugin.MyPlugin.dll

metadata.json schema

Field	Type	Description
publishedFileId	number	Steam file ID (0 if unpublished)
title	string	Workshop item title (max 128 chars)
description	string	Description, supports Steam BBCode (max 8000 chars)
visibility	string	"Public", "FriendsOnly", or "Private"
previewImageRelativePath	string	Relative path to preview image (default "preview.png")
tags	string[]	Up to 20 tags for discoverability
needsFmf	boolean	Appends FMF dependency notice on upload
additionalPreviews	string[]	Relative paths to gallery screenshot images

Using the app

Tabs

Tab	Purpose
Projects	Local workshop projects; search, open editor
New	Create from template (vanilla, MelonLoader, FMF)
My Uploads	Paginated list of your published items with stats
Mod Store	Browse, search, subscribe, vote, and manage mods

Publish workflow

1. Open a project from the Projects tab.
2. Fill in title, description, tags, visibility, preview image.
3. Optionally add gallery screenshots (up to 9 additional images).
4. Write a version changelog (required for first publish).
5. Click Save and upload to Steam.
6. The app:
   • Validates all required fields (upload readiness check).
   • Saves metadata.json.
   • Uploads content/ and preview to Steam.
   • Uploads additional gallery screenshots (if any).
   • Syncs back — re-downloads Steam's version of content, preview image, and gallery screenshots into your local project folder.

Import from Steam

You can import an existing published Workshop item into your local workspace:

1. Go to My Uploads → click an item → Import.
2. The app downloads the content, preview image, gallery screenshots, and creates a local project with the correct metadata.json.

Headless / CI publish

WorkshopUploader.exe --mode publish --path <project-folder>

Optional flags:

• --autocommit — writes a status JSON for external tools.

Steam BBCode reference

Steam Workshop descriptions support BBCode formatting. The editor includes a toolbar with all supported tags. Here is the full reference:

Text formatting

[b]Bold text[/b]
[i]Italic text[/i]
[u]Underlined text[/u]
[strike]Strikethrough text[/strike]

Headings

[h1]Heading 1[/h1]
[h2]Heading 2[/h2]
[h3]Heading 3[/h3]

Links and images

[url=https://example.com]Link text[/url]
[img]https://example.com/image.png[/img]

Lists

[list]
[*] Item 1
[*] Item 2
[*] Item 3
[/list]

Code blocks

[code]
console.log("Hello World");
[/code]

Quotes and spoilers

[quote]Quoted text here[/quote]
[spoiler]Hidden text revealed on click[/spoiler]

Horizontal rule

[hr][/hr]

Tables

[table]
[tr]
[th]Header 1[/th]
[th]Header 2[/th]
[/tr]
[tr]
[td]Cell 1[/td]
[td]Cell 2[/td]
[/tr]
[/table]

Example workshop description

[h1]My Awesome Mod[/h1]

Custom decorations and objects for Data Center.

[h2]Features[/h2]
[list]
[*] 10 new decoration items
[*] 5 custom server rack skins
[*] Compatible with FrikaModFramework
[/list]

[h2]Installation[/h2]
Subscribe to this Workshop item — the game loads it automatically.

[h2]Requirements[/h2]
[list]
[*] Data Center (Steam)
[*] [url=https://melonwiki.xyz]MelonLoader[/url] (for modded items)
[/list]

[h3]Changelog[/h3]
[b]v1.0[/b] — Initial release

[hr][/hr]
[i]Made by YourName — [url=https://discord.gg/your-server]Join the Discord[/url][/i]

Upload readiness checks

Before uploading, the editor runs automated checks:

Check	Error condition	Warning condition
Content folder	content/ missing or empty	—
Title	Empty or > 128 characters	—
Description	> 8000 characters	Empty (recommended)
Visibility	—	Unknown value
Preview image	—	Missing or > 1 MB
Tags	—	No tags set
Content size	—	> 100 MB
Changelog	Empty on first publish	Empty on update

Items with errors cannot be uploaded. Warnings are informational — upload is still possible.

Preview images

Main preview image

• Supports PNG, JPG, JPEG, GIF, and WebP.
• Auto-detected by filename: preview.png, preview.jpg, etc.
• Recommended size: under 1 MB.
• The app auto-detects the format from the file's magic bytes when syncing from Steam.

Gallery screenshots

• Up to 9 additional images per item.
• Stored in screenshots/ under the project root.
• Uploaded in a separate pass after the main content publish.
• Synced back from Steam on publish and import — if screenshots exist on Steam, they are downloaded to your local screenshots/ folder.

Build and deploy

Self-contained release

The app is published as a self-contained Windows executable — no .NET runtime or Windows App SDK install required on the target machine.

dotnet publish WorkshopUploader/WorkshopUploader.csproj -c Release -p:SelfContained=true -p:RuntimeIdentifier=win10-x64

Output: WorkshopUploader/bin/Release/net9.0-windows10.0.19041.0/win10-x64/publish/

Deploy all mods + Gregtools Modmanager to Workshop folders

pwsh -File scripts/Deploy-Release-ToWorkshop.ps1

This builds all framework/plugins/mods and the WorkshopUploader itself, then packages each into a Steamworks-compatible project folder under <GameRoot>/workshop/. The WorkshopUploader is packaged as "Gregtools Modmanager".

Deploy to game directory (local testing)

pwsh -File scripts/Deploy-Release-ToDataCenter.ps1 -IncludeWorkshopUploader

FAQ

General

Q: Do I need to install anything besides the app? No. The release is fully self-contained — .NET runtime and Windows App SDK are bundled. You only need Steam running with a Data Center license.

Q: What Steam App ID does this use? 4170200 (Data Center). The file steam_appid.txt must contain this ID next to the executable.

Q: Can I use this on Linux / macOS? Not currently. The app targets Windows 10+ via .NET MAUI with WinUI.

Projects and workspace

Q: Where are my projects stored? By default under <Data Center install>/workshop/. You can change this in Settings. Fallback if Steam is unavailable: %USERPROFILE%\DataCenterWS.

Q: What is the difference between the workspace and Steam's download folder? The workspace (<GameRoot>/workshop/) is where you author content. The Steam download folder (steamapps/workshop/content/4170200/<id>/) is where Steam installs subscribed items for the game. They are separate locations.

Q: Can I edit a project that was already published? Yes. Open it from Projects, make changes, and click Save and upload to Steam. The app updates the existing Workshop item (using the publishedFileId stored in metadata.json).

Q: Can I import a Workshop item I published from another machine? Yes. Use My Uploads → select the item → Import. The app downloads everything (content, preview, gallery screenshots) and creates a local project.

Publishing

Q: Why can't I upload? The button is greyed out / shows errors. The upload readiness checker found issues. Common blockers:

• content/ folder is missing or empty.
• Title is empty.
• No changelog provided on first publish. Check the readiness panel at the bottom of the editor for details.

Q: Is the changelog required? Yes for the first publish (error if empty). For updates it's recommended but not enforced (warning only).

Q: What happens after I click "Save and upload to Steam"?

1. Metadata is saved locally.
2. Content and preview are uploaded to Steam.
3. Gallery screenshots are uploaded (if any).
4. The app re-downloads everything from Steam to sync your local project (content, preview image, gallery images).

Q: My upload says "Workshop legal agreement must be accepted." You need to accept the Steam Workshop legal agreement for Data Center in your browser. Visit the Workshop page for the game on Steam and accept the agreement.

Q: Can I upload from the command line? Yes: WorkshopUploader.exe --mode publish --path <project-folder>. Useful for CI/CD pipelines.

Descriptions and formatting

Q: Does the description support formatting? Yes, Steam Workshop uses BBCode. The editor includes a toolbar with all supported tags (bold, italic, headings, URLs, images, lists, code, quotes, spoilers, tables). See the BBCode reference above.

Q: What is the maximum description length? 8000 characters.

Q: Can I use Markdown in descriptions? No. Steam Workshop only supports BBCode. Markdown will be displayed as plain text.

Images

Q: What image formats are supported? PNG, JPG/JPEG, GIF, and WebP for both the main preview and gallery screenshots.

Q: How large can the preview image be? Steam recommends under 1 MB. The app warns if it's larger but doesn't block upload.

Q: How many gallery screenshots can I add? Up to 9 additional images. They appear in the image gallery on the Steam Workshop page.

Q: Are my screenshots synced from Steam? Yes. After publishing and during import, gallery screenshots are downloaded from Steam and saved in your project's screenshots/ folder.

Mods and installation

Q: Where does Steam install Workshop mods? <SteamLibrary>/steamapps/workshop/content/4170200/<PublishedFileId>/. See Steam install path for details.

Q: Where does the game look for native mods (manual install)? Data Center_Data/StreamingAssets/Mods/<mod_folder>/. Each subfolder must contain a config.json. See the native mod format reference.

Q: How does the game load Workshop mods? At startup, the game's ModLoader.SyncWorkshopThenLoadAll() queries all subscribed items from Steam, waits for downloads to complete, and copies each into Data Center_Data/StreamingAssets/Mods/workshop_<ID>/. Then LoadAllMods() scans that folder. Asset objects (shopItems, staticItems) load immediately; DLL mods load later at SaveLoad time. The content structure determines what kind of mod it is:

• Native mods (vanilla): config.json + OBJ/PNG assets directly in content/ — no extra tools needed.
• MelonLoader mods: content/Mods/ with .dll files — requires MelonLoader.
• FMF plugins: content/FMF/Plugins/ with .dll files — requires MelonLoader + FMF.

Q: What are the three mod types?

Type	Requirements	Content structure	Use case
Vanilla (native)	None	config.json + .obj + .png	Custom objects, decorations, shop items
MelonLoader	MelonLoader	Mods/*.dll	Code mods (IL2CPP)
FMF plugin	MelonLoader + FMF	FMF/Plugins/*.dll	FrikaModFramework plugins

Q: What model format does the native mod system use? Wavefront OBJ (.obj) for 3D models and PNG (.png) for textures and icons.

Q: What is objectType in config.json? Currently only 0 (passive object) is supported. Active/functional object types may be added in future game updates.

Q: Can I load custom DLLs via the native mod system (without MelonLoader)? Yes. The game's ModLoader has built-in DLL loading via the dlls array in config.json. Your entry class must implement the game's IModPlugin interface. See DLL mods without MelonLoader for details. Note that this feature is marked as experimental by the developer — asset-only mods (shopItems/staticItems) are the safest approach.

Q: Do users need MelonLoader to use Workshop items? Only for MelonLoader and FMF mods. Vanilla/native mods (using config.json) work without any additional tools — just subscribe and play. Mark your project as "Needs FrikaModFramework" if applicable — the app will add an installation notice to the description automatically.

Q: Can I change where native mods are loaded from? Yes. Install the ModPathRedirector MelonLoader plugin into {GameRoot}/Plugins/. It uses steam_api64.dll to trigger Workshop downloads once the Steam client is up; files still land under Data Center_Data/StreamingAssets/Mods/workshop_<ID>/.

Mod Store

Q: How do I enable the Mod Store? Go to Settings → toggle Mod Store on → restart the app.

Q: Can I subscribe to mods from the app? Yes. Browse or search for mods, then click Subscribe. Steam will download the mod automatically.

Troubleshooting

Q: The app won't start / crashes on launch.

• Ensure steam_appid.txt is next to the executable; steam_api64.dll should resolve from the Data Center install (Data Center_Data/Plugins/x86_64/) or from the uploader folder.
• Steam must be running and logged in.
• Check the Windows Event Viewer (Application log) for .NET crash details.
• On Windows 10 < 1809, the app may not work due to WinUI requirements.

Q: "Steam init failed" error in the app.

• Make sure Steam is running and you are logged in.
• Verify you own Data Center (App ID 4170200).
• Check that steam_appid.txt contains 4170200.

Q: My content doesn't show up after subscribing.

• Restart the game — Workshop content is loaded at startup.
• Check steamapps/workshop/content/4170200/ to verify the download exists.
• If the folder is empty, try unsubscribing and re-subscribing.

Q: The preview image doesn't load in the Mod Store.

• The image is loaded from Steam's CDN. Check your internet connection.
• Very large images may take a moment to appear.

See also

• Repository README: WorkshopUploader/README.md
• End-User Guide
• Contributor Guide
• Release