springdoc is a lightweight, open-source library for generating API documentation from Spring Boot applications. It provides support for both OpenAPI 3 and Swagger 2 specifications, allowing developers to document their APIs effortlessly. The library integrates with the Spring framework and requires minimal configuration, making it easy to use. With springdoc, developers can annotate their controller methods with OpenAPI annotations to describe the API operations, request and response bodies, parameters, and more. The library then automatically generates the API documentation in either JSON or YAML format, which can be accessed through a dedicated endpoint. This documentation can be used for testing, client generation, and as a reference for other developers consuming the API. Overall, springdoc simplifies the process of documenting and sharing API specifications in Spring Boot applications.