We automatically test REST API based on their specifications, particularly OpenAPI ones. To our surprise, many of our tests failed, meaning that the OpenAPI definition and the actual API were not an exact match.
g9 is one of the most flexible code-generator tools I’ve seen. It generates both the front-end, the back-end and the database for you. And it’s fully integrated in Eclipse
Our approach to automatically generate GraphQL schemas from UML class diagrams (and IFML interaction models)
Our proposal to automatically infer OpenAPI compliant specifications for REST Web APIs from a set of examples of actual API calls
Details of our UML Profile to model OData Web APIs. Once you have your UML model annotated with OData stereotypes you could automate the generation of your OData definition files.