What is Swagger and how do you use it to document a RESTful API in .NET Core?

Swagger is an open-source tool that helps developers to design, build, and document RESTful APIs. Swagger provides a user interface that allows developers to interact with the API and explore its resources and operations. It also generates documentation for the API, including details such as resource paths, request/response formats, and data models.

In .NET Core, Swagger can be integrated using the Swashbuckle.AspNetCore package. To use Swashbuckle.AspNetCore, you need to follow these steps:

1. Install the Swashbuckle.AspNetCore package using the NuGet Package Manager or the Package Manager Console.


2. In the Startup.cs file, add the following lines to the ConfigureServices method:

services.AddSwaggerGen(c =>
{
    c.SwaggerDoc("v1", new OpenApiInfo { Title = "My API", Version = "v1" });
});

 

3. In the same file, add the following lines to the Configure method:

app.UseSwagger();
app.UseSwaggerUI(c =>
{
    c.SwaggerEndpoint("/swagger/v1/swagger.json", "My API V1");
});

 

4. Run the application and navigate to http://localhost:<port>/swagger to view the Swagger UI.

 

You can customize the Swagger documentation by adding attributes to your API controllers and actions. For example, you can add the [ProducesResponseType] attribute to specify the expected response type for an action. You can also add XML comments to your code to provide additional documentation for the API.

Overall, using Swagger to document your API can help to improve its usability and reduce the amount of time required to write and maintain documentation.