SimulAPI

The backend is not ready and the frontend team is idle. The usual response is that everyone writes their own mock, so now there are four mocks that disagree with each other and with the spec, and integration day is where you find out. SimulAPI turns an OpenAPI spec into a running, validating mock in under a minute. It validates because a mock that accepts anything lets you build against a contract you are already breaking. There is no persistence layer and no scripted stateful behaviour, deliberately: the moment a mock has its own state model it becomes a second implementation of your backend, and teams end up debugging the mock.