Mod Loader/CSharp APIs

Use a C# plugin to add a keyboard shortcut, change accessory placement, or react when a player changes a setting. To add fabrics, garments, accessories, or dialogue, you can start with a content pack.

For methods, overloads, and hooks grouped by task, use the API index.

What you need

Dressmaker with Mod Loader installed. Find the game folder containing Dressmaker.exe.
The .NET SDK and the .NET Framework 4.7.2 targeting pack. Visual Studio with .NET desktop development is another way to get the build tools.
A text editor, such as VS Code or Visual Studio.

A plugin is a DLL loaded by BepInEx when Dressmaker starts. The example below uses the DLLs already installed with your game, so you don't need to download copies of Unity or the loader assemblies. If you have more than one game installation, pick one game folder for the first build.

Make a plugin

Create a folder called HelloDressmaker. Put these two files in it.

Plugin.cs

using BepInEx;

[BepInPlugin("example.dressmaker.hello", "Hello Dressmaker", "1.0.0")]
[BepInDependency("yuu.dressmaker.mods")]
public sealed class HelloDressmaker : BaseUnityPlugin
{
    private void Awake()
    {
        Logger.LogInfo("Hello Dressmaker loaded.");
    }
}

Change example.dressmaker.hello to your own unique plugin ID when you make a real mod. The dependency tells BepInEx to load Mod Loader first. Awake runs when BepInEx loads your plugin; the log message gives you an easy first check.

HelloDressmaker.csproj

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFramework>net472</TargetFramework>
    <LangVersion>latest</LangVersion>
  </PropertyGroup>
  <ItemGroup>
    <Reference Include="BepInEx">
      <HintPath>$(DressmakerGameRoot)\BepInEx\core\BepInEx.dll</HintPath>
      <Private>false</Private>
    </Reference>
    <Reference Include="UnityEngine.CoreModule">
      <HintPath>$(DressmakerGameRoot)\Dressmaker_Data\Managed\UnityEngine.CoreModule.dll</HintPath>
      <Private>false</Private>
    </Reference>
    <Reference Include="UnityEngine">
      <HintPath>$(DressmakerGameRoot)\Dressmaker_Data\Managed\UnityEngine.dll</HintPath>
      <Private>false</Private>
    </Reference>
    <Reference Include="DressmakerMods">
      <HintPath>$(DressmakerGameRoot)\BepInEx\plugins\DressmakerMods.dll</HintPath>
      <Private>false</Private>
    </Reference>
  </ItemGroup>
  <Target Name="CheckGameFolder" BeforeTargets="ResolveReferences">
    <Error Condition="!Exists('$(DressmakerGameRoot)\Dressmaker.exe')"
           Text="Set DressmakerGameRoot to the folder containing Dressmaker.exe." />
  </Target>
</Project>

These references let the compiler find BepInEx, Unity, and Mod Loader. Private=false keeps copies of the game's DLLs out of your build output. Add other game assemblies only when your code uses them.

Compile it

Open PowerShell in the HelloDressmaker folder and run:

dotnet build .\HelloDressmaker.csproj -c Release -p:DressmakerGameRoot='C:\path\to\Dressmaker'

Replace the sample path with the folder that contains Dressmaker.exe. Keep the quotes if your path has spaces. The compiled file is bin\Release\net472\HelloDressmaker.dll. If the build says it cannot find .NET Framework 4.7.2 reference assemblies, install its Developer Pack or targeting pack. If a reference is missing, check that the path points to a Mod Loader installation and that the named DLL exists there.

Try it in the game

Create BepInEx\plugins\HelloDressmaker in your game folder.
Copy HelloDressmaker.dll into that folder. The build's copies of game or BepInEx assemblies do not belong in your plugin folder.
Start Dressmaker, then open BepInEx\LogOutput.log and look for Hello Dressmaker loaded.

If the message is missing, check the same log for a load error. Make sure you copied the new DLL into the game's actual plugin folder and that Mod Loader is installed. After changing your code, build again, replace your DLL, and restart the game.

Add something useful

Pick an API below and copy its smallest example into your plugin. Add using DressmakerMods; when the example uses a Mod Loader type. Use the dependency version and assembly references given with the example. For audio or shaders, follow Build an AssetBundle before trying to load one. For instance, the settings page shows how to add a toggle to Mod Settings.

The API examples show where to put each call. For example, settings can be registered in Awake, but music changes wait for the music controller. When an example stores a registration and disposes it in OnDestroy, keep both parts: disposing removes the command, setting tab, or other addition when the plugin unloads.

For more about BepInEx plugins themselves, see the BepInEx plugin tutorial.

For custom fabric shaders across game views, see Add a custom fabric shader and the Fabric render API.

Choose what you need

To...	Open
Start a plugin, wait for content, handle events, and release resources	Plugin lifecycle
Track textures in custom previews or request original pixels	Texture use API
Register your plugin, stream textures, keep save data and share input	Plugin compatibility APIs
Load accessory models when needed and receive loading callbacks	AccessoryPrefabApi
Replace room art, sprites, and menu pictures	ArtModApi
Add a tab with toggles, sliders, or actions in Mod Settings	ModSettingsApi
Register fabrics or load a shader AssetBundle	FabricModApi
Replace room art, character portraits, sprite sheets or material colours	ArtModApi and MannequinColorApi
React to garment selection, panel creation or fabric changes	GarmentEventsApi
Add garment pieces and tags with icons or sketches	GarmentModApi
Add or hide rotating music tracks	SoundtrackModApi
Change shop purchase sounds	PurchaseSoundModApi
Change sketchbook pencil colors or select a drawing color	PencilColorModApi
Add an in-game debug command	DebugConsoleApi
Add remappable keys for your mod	ModKeybindApi
Measure or snap accessories and trim points while placing	AccessoryPlacementApi

Friendship rewards

Give garment patterns when a native or modded client reaches a friendship level. See register a reward in C#.

Back to the Mod Loader guide