How to omit methods from Swagger documentation on WebAPI using Swashbuckle

You can add the following attribute to Controllers and Actions to exclude them from the generated documentation: [ApiExplorerSettings(IgnoreApi = true)]

Someone posted the solution on github so I'm going to paste it here. All credits goes to him. https://github.com/domaindrivendev/Swashbuckle/issues/153#issuecomment-213342771

Create first an Attribute class

[AttributeUsage(AttributeTargets.Method | AttributeTargets.Class)]
public class HideInDocsAttribute : Attribute
{
}

Then create a Document Filter class

public class HideInDocsFilter : IDocumentFilter
{
    public void Apply(SwaggerDocument swaggerDoc, SchemaRegistry schemaRegistry, IApiExplorer apiExplorer)
    {
        foreach (var apiDescription in apiExplorer.ApiDescriptions)
        {
            if (!apiDescription.ActionDescriptor.ControllerDescriptor.GetCustomAttributes<HideInDocsAttribute>().Any() && !apiDescription.ActionDescriptor.GetCustomAttributes<HideInDocsAttribute>().Any()) continue;
            var route = "/" + apiDescription.Route.RouteTemplate.TrimEnd('/');
            swaggerDoc.paths.Remove(route);
        }
    }
}

Then in Swagger Config class, add that document filter

public class SwaggerConfig
{
    public static void Register(HttpConfiguration config)
    {
        var thisAssembly = typeof(SwaggerConfig).Assembly;

        config
             .EnableSwagger(c =>
                {
                    ...                       
                    c.DocumentFilter<HideInDocsFilter>();
                    ...
                })
            .EnableSwaggerUi(c =>
                {
                    ...
                });
    }
}

Last step is to add [HideInDocsAttribute] attribute on the Controller or Method you don't want Swashbuckle to generate documentation.