OpenAPI Specification (OAS), formerly known as Swagger, is widely used for documenting APIs, yet managing OAS files can be challenging, prompting the development of tools that integrate documentation directly into the code. By using npm to install the 'oas' command-line tool and 'Swagger Inline', developers can create, manage, and upload OAS files with ease, maintaining documentation alongside code for better version control and ease of updates. The 'oas' tool allows for creation of OAS files through a guided process, while 'Swagger Inline' simplifies endpoint documentation by extracting OAS definitions directly from code comments, reducing verbosity with a shorthand syntax for parameters. Once the OAS file is ready, it can be hosted and shared using 'oas host' which uploads the file to a repository, providing a shareable URL that can be integrated with other services like ReadMe. This approach not only facilitates the maintenance of current API documentation but also supports automation and collaboration through features like version management and the use of a mock server for testing API responses.