APIs, commonly described in OpenAPI format, serve as essential integration tools across various systems by providing a single source of truth for creating API clients, servers, and documentation. Redocly, an open-source CLI tool, facilitates the generation of user-friendly API documentation from OpenAPI descriptions, offering a streamlined process for both API providers and consumers. To utilize Redocly, users must first install NodeJS and the NPM package manager, or alternatively use Docker, and then execute commands to produce HTML documentation, such as the example Petstore API. Customization of the documentation's appearance through configuration files like redocly.yaml allows for branding consistency. Additionally, Redocly supports a live preview feature, enabling real-time updates as users edit OpenAPI descriptions, and offers tools to check API standards and manage large OpenAPI files.