All 15 API Documentation with Swagger/OpenAPI questions
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How do you organize and group endpoints in Swagger UI by tags or API version? How do you customize example values shown in Swagger UI for request and response bodies? How do you validate that an API's actual behavior matches its published OpenAPI specification, preventing documentation drift? How do you version your OpenAPI documentation to reflect API versioning implemented via the Asp.Versioning library? How do you document authentication requirements (like a JWT bearer token) in Swagger UI so users can test authenticated endpoints interactively? How does the newer built-in Microsoft.AspNetCore.OpenApi package (introduced in .NET 9) differ from the third-party Swashbuckle package? How would you exclude specific endpoints or entire controllers from appearing in the generated Swagger documentation? How would you generate a client SDK automatically from an ASP.NET Core API's OpenAPI specification? What is 'design-first' versus 'code-first' API development, and how does OpenAPI tooling support each approach? How do you document and test webhook or callback endpoints (server-initiated calls to a client-registered URL) in OpenAPI 3.1?
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ASP.NET Core › API Documentation with Swagger/OpenAPI

How do you add global metadata (like a description, contact info, and license) to the top level of a generated OpenAPI document?

Intermediate

Answer

SwaggerDoc's OpenApiInfo object accepts a Title, Version, Description, Contact, and License, populating the top-level info section of the OpenAPI document and Swagger UI's header -- giving consumers essential context (who maintains the API, how to get support, licensing terms) beyond just the endpoint-level details.
builder.Services.AddSwaggerGen(c => {
    c.SwaggerDoc("v1", new OpenApiInfo {
        Title = "Order Management API",
        Version = "v1",
        Description = "Handles order creation, tracking, and fulfillment.",
        Contact = new OpenApiContact { Name = "API Support", Email = "api-support@company.com" },
        License = new OpenApiLicense { Name = "Proprietary" }
    });
});
Real-world example A public API's Swagger UI header prominently displays a support email and a clear description of the API's purpose, reducing the number of basic 'what does this API do' support inquiries the team receives.

Common follow-ups: How does this metadata surface in generated client SDKs?;What other top-level OpenAPI fields (like termsOfService) are commonly populated?

API Documentation with Swagger/OpenAPI;RESTful Web APIs & Controllers
All 15 API Documentation with Swagger/OpenAPI questions