1. Add the NuGet package to your project.

dotnet add package AltV.Community.MValueAdapters.Generators

2. In case there are CS0436 warnings during compilation, you must add these attributes to your <PackageReference>.

<PackageReference Include="AltV.Community.MValueAdapters.Generators" PrivateAssets="all" ExcludeAssets="runtime" />

Note: If you use a shared project between client and server, only add the NuGet to the shared project and neither to the client nor server project to avoid ambigious references.

1. Add MValueAdapter attribute to your class.

using AltV.Community.MValueAdapters.Generators;

[MValueAdapter]
public class ParentDto
{
    public string First { get; set; } = string.Empty;
    public string Second { get; set; } = string.Empty;
    public ChildDto Dto { get; set; } = null!;
}

[MValueAdapter]
public class ChildDto
{
    public string First { get; set; } = string.Empty;
    public string Second { get; set; } = string.Empty;
}

2. Register the MValue adapters generated when the resource (client / server) starts.

public override void OnStart()
{
    AltExtensions.RegisterAdapters();
}

Huge thanks to deluvas1911 for sharing his great work and allowing me to open source this.

If you'd like to contribute, some adjustments need to be made to the project setup.

1. Fork the project, clone and build it dotnet build.
2. Remove any existing <PackageReference> to this project from your Server/Client project.
3. Add the following lines to an <ItemGroup> and replace the Include= value with the relative paths:

<ProjectReference Include="..\AltV.Community.MValueAdapters.Generators\AltV.Community.MValueAdapters.Generators.csproj" OutputItemType="Analyzer" ReferenceOutputAssembly="false" PrivateAssets="all" />
<ProjectReference Include="..\AltV.Community.MValueAdapters.Generators.Abstractions\AltV.Community.MValueAdapters.Generators.Abstractions.csproj" OutputItemType="Analyzer" />

4. Add the following line to an <ItemGroup> in your Server/Client project to view generated files:

<EmitCompilerGeneratedFiles>true</EmitCompilerGeneratedFiles>

5. In your Server/Client project, run dotnet clean before building, to ensure cache is cleared.