JsonTag.CSharp 1.0.0

dotnet add package JsonTag.CSharp --version 1.0.0
                    
NuGet\Install-Package JsonTag.CSharp -Version 1.0.0
                    
This command is intended to be used within the Package Manager Console in Visual Studio, as it uses the NuGet module's version of Install-Package.
<PackageReference Include="JsonTag.CSharp" Version="1.0.0" />
                    
For projects that support PackageReference, copy this XML node into the project file to reference the package.
<PackageVersion Include="JsonTag.CSharp" Version="1.0.0" />
                    
Directory.Packages.props
<PackageReference Include="JsonTag.CSharp" />
                    
Project file
For projects that support Central Package Management (CPM), copy this XML node into the solution Directory.Packages.props file to version the package.
paket add JsonTag.CSharp --version 1.0.0
                    
#r "nuget: JsonTag.CSharp, 1.0.0"
                    
#r directive can be used in F# Interactive and Polyglot Notebooks. Copy this into the interactive tool or source code of the script to reference the package.
#:package JsonTag.CSharp@1.0.0
                    
#:package directive can be used in C# file-based apps starting in .NET 10 preview 4. Copy this into a .cs file before any lines of code to reference the package.
#addin nuget:?package=JsonTag.CSharp&version=1.0.0
                    
Install as a Cake Addin
#tool nuget:?package=JsonTag.CSharp&version=1.0.0
                    
Install as a Cake Tool

json-tag

C# support for JSON#.

Configures System.Text.Json to use the JSON# convention.

Install

dotnet add package JsonTag.CSharp

Usage

Mark your base type:

[JsonTag]
public abstract record Shape;

public sealed record Circle : Shape
{
    public double Radius { get; init; }
}

public sealed record Rectangle : Shape
{
    public double Width { get; init; }
    public double Height { get; init; }
}

Serialize and deserialize:

Shape shape = new Circle { Radius = 4 };
var json = JsonSerializer.Serialize(shape, JsonTagOptions.Default);
// {"#type":"Circle","radius":4}

var deserialized = JsonSerializer.Deserialize<Shape>(json, JsonTagOptions.Default);

Custom tag names:

[JsonTagName("Car")]
public sealed record PersonalVehicle : Vehicle
{
    public string Make { get; init; } = "";
}

Add to existing options:

var options = new JsonSerializerOptions { WriteIndented = true }
    .WithJsonTag();

ASP.NET Core:

builder.Services.ConfigureHttpJsonOptions(options =>
    options.SerializerOptions = JsonTagOptions.Default);

API

Type Description
[JsonTag] Marker attribute on base class/interface
[JsonTagName("X")] Custom #type value on a subtype
JsonTagResolver Type info resolver — auto-discovers subtypes
JsonTagOptions.Default Pre-configured JsonSerializerOptions
.WithJsonTag() Extension method — adds JsonTag to existing options

Subtype discovery

Subtypes are discovered automatically from loaded assemblies that directly reference the base type's assembly. No manual registration needed.

Product Compatible and additional computed target framework versions.
.NET net10.0 is compatible.  net10.0-android was computed.  net10.0-browser was computed.  net10.0-ios was computed.  net10.0-maccatalyst was computed.  net10.0-macos was computed.  net10.0-tvos was computed.  net10.0-windows was computed. 
Compatible target framework(s)
Included target framework(s) (in package)
Learn more about Target Frameworks and .NET Standard.
  • net10.0

    • No dependencies.

NuGet packages

This package is not used by any NuGet packages.

GitHub repositories

This package is not used by any popular GitHub repositories.

Version Downloads Last Updated
1.0.0 111 6/16/2026
0.1.7 118 3/30/2026
0.1.6 103 3/30/2026
0.1.5 106 3/30/2026
0.1.4 107 3/30/2026
0.1.2 103 3/30/2026
0.1.1 115 3/30/2026