AspNetCore.Docs/aspnetcore/tutorials/getting-started-with-swashbuckle.md

title	author	description	ms.author	ms.custom	ms.date	uid
Get started with Swashbuckle and ASP.NET Core	zuckerthoben	Learn how to add Swashbuckle to your ASP.NET Core web API project to integrate the Swagger UI.	scaddie	mvc	06/29/2018	tutorials/get-started-with-swashbuckle

Get started with Swashbuckle and ASP.NET Core

By Shayne Boyer and Scott Addie

View or download sample code (how to download)

There are three main components to Swashbuckle:

• Swashbuckle.AspNetCore.Swagger: a Swagger object model and middleware to expose SwaggerDocument objects as JSON endpoints.

• Swashbuckle.AspNetCore.SwaggerGen: a Swagger generator that builds SwaggerDocument objects directly from your routes, controllers, and models. It's typically combined with the Swagger endpoint middleware to automatically expose Swagger JSON.

• Swashbuckle.AspNetCore.SwaggerUI: an embedded version of the Swagger UI tool. It interprets Swagger JSON to build a rich, customizable experience for describing the Web API functionality. It includes built-in test harnesses for the public methods.

Package installation

Swashbuckle can be added with the following approaches:

Visual Studio

• From the Package Manager Console window:

  • Go to View > Other Windows > Package Manager Console

  • Navigate to the directory in which the TodoApi.csproj file exists

  • Execute the following command:

    Install-Package Swashbuckle.AspNetCore
    

• From the Manage NuGet Packages dialog:

  • Right-click the project in Solution Explorer > Manage NuGet Packages
  • Set the Package source to "nuget.org"
  • Enter "Swashbuckle.AspNetCore" in the search box
  • Select the "Swashbuckle.AspNetCore" package from the Browse tab and click Install

Visual Studio for Mac

• Right-click the Packages folder in Solution Pad > Add Packages...
• Set the Add Packages window's Source drop-down to "nuget.org"
• Enter "Swashbuckle.AspNetCore" in the search box
• Select the "Swashbuckle.AspNetCore" package from the results pane and click Add Package

Visual Studio Code

Run the following command from the Integrated Terminal:

dotnet add TodoApi.csproj package Swashbuckle.AspNetCore

.NET Core CLI

Run the following command:

dotnet add TodoApi.csproj package Swashbuckle.AspNetCore

---

Add and configure Swagger middleware

Add the Swagger generator to the services collection in the Startup.ConfigureServices method:

::: moniker range="<= aspnetcore-2.0"

[!code-csharp]

::: moniker-end

::: moniker range=">= aspnetcore-2.1"

[!code-csharp]

::: moniker-end

Import the following namespace to use the Info class:

[!code-csharp]

In the Startup.Configure method, enable the middleware for serving the generated JSON document and the Swagger UI:

[!code-csharp]

Launch the app, and navigate to http://localhost:<port>/swagger/v1/swagger.json. The generated document describing the endpoints appears as shown in Swagger specification (swagger.json).

The Swagger UI can be found at http://localhost:<port>/swagger. Explore the API via Swagger UI and incorporate it in other programs.

[!TIP] To serve the Swagger UI at the app's root (http://localhost:<port>/), set the RoutePrefix property to an empty string:

[!code-csharp]

Customize and extend

Swagger provides options for documenting the object model and customizing the UI to match your theme.

API info and description

The configuration action passed to the AddSwaggerGen method adds information such as the author, license, and description:

[!code-csharp]

The Swagger UI displays the version's information:

XML comments

XML comments can be enabled with the following approaches:

Visual Studio

::: moniker range=">= aspnetcore-2.0"

• Right-click the project in Solution Explorer and select Edit <project_name>.csproj.
• Manually add the highlighted lines to the .csproj file:

[!code-xml]

::: moniker-end

::: moniker range="<= aspnetcore-1.1"

• Right-click the project in Solution Explorer and select Properties.
• Check the XML documentation file box under the Output section of the Build tab.

::: moniker-end

Visual Studio for Mac

::: moniker range=">= aspnetcore-2.0"

• From the Solution Pad, press control and click the project name. Navigate to Tools > Edit File.
• Manually add the highlighted lines to the .csproj file:

[!code-xml]

::: moniker-end

::: moniker range="<= aspnetcore-1.1"

• Open the Project Options dialog > Build > Compiler
• Check the Generate xml documentation box under the General Options section

::: moniker-end

Visual Studio Code

Manually add the highlighted lines to the .csproj file:

::: moniker range=">= aspnetcore-2.0"

[!code-xml]

::: moniker-end

::: moniker range="<= aspnetcore-1.1"

[!code-xml]

::: moniker-end

---

Enabling XML comments provides debug information for undocumented public types and members. Undocumented types and members are indicated by the warning message. For example, the following message indicates a violation of warning code 1591:

warning CS1591: Missing XML comment for publicly visible type or member 'TodoController.GetAll()'

Suppress warnings by defining a semicolon-delimited list of warning codes to ignore in the .csproj file. Appending the warning codes to $(NoWarn); applies the C# default values too.

::: moniker range=">= aspnetcore-2.0"

[!code-xml]

::: moniker-end

::: moniker range="<= aspnetcore-1.1"

[!code-xml]

::: moniker-end

Configure Swagger to use the generated XML file. For Linux or non-Windows operating systems, file names and paths can be case-sensitive. For example, a TodoApi.XML file is valid on Windows but not CentOS.

::: moniker range=">= aspnetcore-2.1"

[!code-csharp]

::: moniker-end

::: moniker range="= aspnetcore-2.0"

[!code-csharp]

::: moniker-end

::: moniker range="<= aspnetcore-1.1"

[!code-csharp]

::: moniker-end

In the preceding code, Reflection is used to build an XML file name matching that of the Web API project. The AppContext.BaseDirectory property is used to construct a path to the XML file.

Adding triple-slash comments to an action enhances the Swagger UI by adding the description to the section header. Add a <summary> element above the Delete action:

[!code-csharp]

The Swagger UI displays the inner text of the preceding code's <summary> element:

The UI is driven by the generated JSON schema:

"delete": {
    "tags": [
        "Todo"
    ],
    "summary": "Deletes a specific TodoItem.",
    "operationId": "ApiTodoByIdDelete",
    "consumes": [],
    "produces": [],
    "parameters": [
        {
            "name": "id",
            "in": "path",
            "description": "",
            "required": true,
            "type": "integer",
            "format": "int64"
        }
    ],
    "responses": {
        "200": {
            "description": "Success"
        }
    }
}

Add a <remarks> element to the Create action method documentation. It supplements information specified in the <summary> element and provides a more robust Swagger UI. The <remarks> element content can consist of text, JSON, or XML.

::: moniker range="<= aspnetcore-2.0"

[!code-csharp]

::: moniker-end

::: moniker range=">= aspnetcore-2.1"

[!code-csharp]

::: moniker-end

Notice the UI enhancements with these additional comments:

Data annotations

Decorate the model with attributes, found in the System.ComponentModel.DataAnnotations namespace, to help drive the Swagger UI components.

Add the [Required] attribute to the Name property of the TodoItem class:

[!code-csharp]

The presence of this attribute changes the UI behavior and alters the underlying JSON schema:

"definitions": {
    "TodoItem": {
        "required": [
            "name"
        ],
        "type": "object",
        "properties": {
            "id": {
                "format": "int64",
                "type": "integer"
            },
            "name": {
                "type": "string"
            },
            "isComplete": {
                "default": false,
                "type": "boolean"
            }
        }
    }
},

Add the [Produces("application/json")] attribute to the API controller. Its purpose is to declare that the controller's actions support a response content type of application/json:

::: moniker range="<= aspnetcore-2.0"

[!code-csharp]

::: moniker-end

::: moniker range=">= aspnetcore-2.1"

[!code-csharp]

::: moniker-end

The Response Content Type drop-down selects this content type as the default for the controller's GET actions:

As the usage of data annotations in the Web API increases, the UI and API help pages become more descriptive and useful.

Describe response types

Consuming developers are most concerned with what's returned—specifically response types and error codes (if not standard). The response types and error codes are denoted in the XML comments and data annotations.

The Create action returns an HTTP 201 status code on success. An HTTP 400 status code is returned when the posted request body is null. Without proper documentation in the Swagger UI, the consumer lacks knowledge of these expected outcomes. Fix that problem by adding the highlighted lines in the following example:

::: moniker range="<= aspnetcore-2.0"

[!code-csharp]

::: moniker-end

::: moniker range=">= aspnetcore-2.1"

[!code-csharp]

::: moniker-end

The Swagger UI now clearly documents the expected HTTP response codes:

Customize the UI

The stock UI is both functional and presentable. However, API documentation pages should represent your brand or theme. Branding the Swashbuckle components requires adding the resources to serve static files and building the folder structure to host those files.

If targeting .NET Framework or .NET Core 1.x, add the Microsoft.AspNetCore.StaticFiles NuGet package to the project:

<PackageReference Include="Microsoft.AspNetCore.StaticFiles" Version="2.0.0" />

The preceding NuGet package is already installed if targeting .NET Core 2.x and using the metapackage.

Enable the static files middleware:

[!code-csharp]

Acquire the contents of the dist folder from the Swagger UI GitHub repository. This folder contains the necessary assets for the Swagger UI page.

Create a wwwroot/swagger/ui folder, and copy into it the contents of the dist folder.

Create a custom.css file, in wwwroot/swagger/ui, with the following CSS to customize the page header:

[!code-css]

Reference custom.css in the index.html file, after any other CSS files:

[!code-html]

Browse to the index.html page at http://localhost:<port>/swagger/ui/index.html. Enter http://localhost:<port>/swagger/v1/swagger.json in the header's textbox, and click the Explore button. The resulting page looks as follows:

There's much more you can do with the page. See the full capabilities for the UI resources at the Swagger UI GitHub repository.