This segment showcases the practical application of FastAPI's built-in Swagger UI documentation. The presenter demonstrates how to use the interactive interface to test API endpoints, execute queries, view responses (including HTTP status codes), and examine the JSON output, highlighting the ease of use and immediate feedback provided by this integrated documentation system. This eliminates the need for separate documentation updates and provides a streamlined workflow for developers and API users. FastAPI's built-in documentation, accessible via `/docs`, uses Swagger UI (and optionally Redoc). It automatically generates API documentation from path operations, eliminating manual updates. Interactive features let you test endpoints directly within the browser, showing requests, responses, and even cURL commands.