Swagger Petstore is a sample Java project that implements the OpenAPI 3 specification, built on the swagger-inflector framework. It provides a stand-alone petstore server that can be run locally via Maven and Jetty or deployed using Docker, and includes an interactive HTML5-based API UI for exploring and testing the API endpoints. The project is hosted at petstore3.swagger.io and welcomes contributions to both the codebase and API design, with the OpenAPI specification defined in an openapi.yaml file.