This is often true in professional settings. "Just build the UI for this, and the API team will catch up". I object-- give me an OpenAPI spec that we agree upon

This is often true in professional settings. "Just build the UI for this, and the API team will catch up". I object-- give me an OpenAPI spec that we agree upon in advance. Front-end today involves building up a lot of in-memory data structures, and I haven't built something useful if the JSON shape I attempt giving you, is not what the backend team is expecting.