Introduction OpenAPI, formerly known as “Swagger”, is an API description standard. I will only go into detail here, so suffice to say, at work we have a server that uses Python’s FastAPI to define HTTP API endpoints, and we have multiple clients that access these endpoints. First and foremost, we have a web user interface written in Elm. Previously, we hard-coded the requests we made to the server, which meant that if the server API changed, our clients had to be changed as well, and there was no way to automatically check if anything was broken....