I've tried two approaches. 1) write code, generate Swagger/OpenAPI from it. Works pretty good with big frameworks like Spring for Java or Symfony for PHP. Draw

I've tried two approaches. 1) write code, generate Swagger/OpenAPI from it. Works pretty good with big frameworks like Spring for Java or Symfony for PHP. Drawback: it is too easy to change API, tends to broke BC too often. 2) write Swagger/OpenAPI, generate code stubs from it. Works good enough with Go and TypeScript. Tends to keep client-server contracts stable. Drawback: server code is overly complicated, needs extra layer of DTO to convert from domain terms to API models. edit: 2nd approach also good for autotesting.