Swagger run locally but not on IIS, not resolving base path

Try using a relative path:

setupAction.SwaggerEndpoint("../swagger/Imaging4CastApiSpecification/swagger.json", "4Cast API");

Please note answer and explanation from the following issue: SwashBuckle

Here is my Swagger config for once of PRD application. Hope it helps

 public static IServiceCollection AddSwaggerConfig(this IServiceCollection services, IHostingEnvironment env,            string title, string version)            => services.AddSwaggerGen(c =>            {                //Ensure XML Document File of project is checked for both Debug and Release mode                c.IncludeXmlComments("Your App.xml");                //Display Enum name                c.DescribeAllEnumsAsStrings();                //c.OperationFilter<AddRequiredHeaderParameter>();                    //Authentication for Bearer                    c.AddSecurityDefinition("Bearer",                        new ApiKeyScheme                        {                            In = "header",                            Description = "Please enter JWT with Bearer into field",                            Name = "Authorization",                            Type = "apiKey"                        });                    c.AddSecurityRequirement(new Dictionary<string, IEnumerable<string>>                    {                        {"Bearer", Enumerable.Empty<string>()}                    });                c.SwaggerDoc(version, new Info                {                    Title = title,                    Version = version,                    Description = "",                    Contact = new Contact                    {                        Email = "Support@ABC.com",                        Name = ""                    }                });            });

Startup file

             app.                //Swagger                .UseSwagger()                .UseSwaggerUI(c =>                {                    c.SwaggerEndpoint($"./{_version}/swagger.json", Title);                });

The version is app variable from Config file which will be filtered by CI/CD

Swagger does not support Virtual Directory by default. Try and add this to your Startup.cs

    app.UseSwagger(c =>        {               c.RouteTemplate = "virtual_path/{documentName}/swagger.json";        });     app.UseSwaggerUI(c =>        {            //Include virtual directory          c.RoutePrefix = "virtual_path";// add your virtual path here.            c.SwaggerEndpoint("v1/swagger.json", "Api v1");        });