The Swagger (Open API) toolchain for .NET, Web API and TypeScript.
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NSwag: The Swagger (Open API) toolchain for .NET, Web API and TypeScript

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NSwag is a Swagger 2.0 API (OpenAPI) toolchain for .NET, Web API, TypeScript (jQuery, AngularJS, Angular 2, Aurelia, KnockoutJS, and more) and other platforms, written in C#. The Swagger specification uses JSON and JSON Schema to describe a RESTful web API. The NSwag project provides tools to generate Swagger specifications from existing ASP.NET Web API controllers and client code from these Swagger specifications.

The project combines the functionality of Swashbuckle (Swagger generation) and AutoRest (client generation) in one toolchain. This way a lot of incompatibilites can be avoided and features which are not well described by the Swagger specification or JSON Schema are better supported (e.g. inheritance, enum and reference handling). The NSwag project heavily uses NJsonSchema for .NET for JSON Schema handling and C#/TypeScript class/interface generation.


The project is developed and maintained by Rico Suter and other contributors.

Ways to use the toolchain:


Swagger Generators:

Code Generators:

  • TypeScript Client
    • SwaggerToTypeScriptClientGenerator
      • Generates TypeScript clients from a Swagger specification
      • Available templates/supported libraries:
        • JQuery with Callbacks, JQueryCallbacks
        • JQuery with promises JQueryPromises
        • AngularJS using $http, AngularJS
        • Angular 2 using the http service, Angular2
        • window.fetch API and ES6 promises, Fetch (use this template in your React/Redux app)
        • Aurelia using the HttpClient from aurelia-fetch-client, Aurelia (based on the Fetch template)
  • CSharp Client
  • CSharp WebAPI Controllers (contract first/schema first development)


NPM Packages

  • NSwag: Command line tools (.NET and .NET Core) distributed as NPM package

NuGet Packages

  • NSwag.Core (PCL 259 / .NETStandard 1.0):
    • The Swagger reader and writer classes
  • NSwag.Annotations (PCL 259 / .NETStandard 1.0):
    • Attributes to decorate Web API controllers to control the Swagger generation
  • NSwag.SwaggerGeneration (PCL 259 / .NETStandard 1.0):
    • Classes to generate Swagger specifications
  • NSwag.SwaggerGeneration.WebApi (PCL 259 / .NETStandard 1.0):
    • Classes to generate Swagger specifications from Web API controllers
  • NSwag.CodeGeneration (PCL 259 / .NETStandard 1.0):
    • Base classes to generate clients from Swagger specifications
  • NSwag.CodeGeneration.CSharp (PCL 259 / .NETStandard 1.0):
    • Classes to generate C# clients from Swagger specifications
  • NSwag.CodeGeneration.TypeScript (PCL 259 / .NETStandard 1.0):
    • Classes to generate TypeScript clients from Swagger specifications
  • NSwag.AssemblyLoader (.NET 4.5+):
    • Classes to load assemblies in an isolated AppDomain and generate Swagger specs from Web API controllers
  • NSwag.AssemblyLoaderCore (.NET Core, .NETStandard 1.6):
    • Classes to load assemblies in an AssemblyLoaderContext and generate Swagger specs from Web API controllers
  • NSwag.MSBuild (MSBuild .targets):
    • Adds a .targets file to your Visual Studio project, so that you can run the NSwag command line tool in an MSBuild target
  • NSwag.AspNetCore (.NETStandard 1.6 and .NET 4.5.1+):
  • NSwag.AspNet.Owin (.NET 4.5+):
    • ASP.NET Core/OWIN middlewares for serving Swagger specifications and Swagger UI
  • NSwag.AspNet.WebApi (.NET 4.5+):
  • NSwagStudio (Chocolatey, Windows):
    • Package to install the NSwagStudio and command line tools via Chocolatey
  • NSwag.Commands (PCL 259 / .NETStandard 1.0):
    • Commands for the command line tool implementations and UI
  • NSwag.ConsoleCore (PCL 259 / .NETStandard 1.0):
    • Command line tool for .NET Core (dotnet nswag)

CI NuGet Feed:

The NuGet packages may require the Microsoft.NETCore.Portable.Compatibility package on .NET Core/UWP targets (if mscorlib is missing).


Usage in C#

The following code shows how to read a Swagger specification and generate C# client classes to call the described web services:

var swaggerSettings = new WebApiToSwaggerGeneratorSettings();
var swaggerGenerator = new WebApiToSwaggerGenerator(swaggerSettings);

var document = await swaggerGenerator.GenerateForControllerAsync<PersonsController>();

var clientSettings = new SwaggerToCSharpClientGeneratorSettings 
    ClassName = "MyClass",
    Namespace = "MyNamespace"
var clientGenerator = new SwaggerToCSharpClientGenerator(document, clientSettings);

var code = clientGenerator.GenerateFile();

Check out the project Wiki for more information.


The generators can be used in a comfortable and simple Windows GUI called NSwagStudio: