We are pretty much right back where we started with OpenAPI. You can generate a client (or a server) from this YAML file that a lot of frameworks can generate f

We are pretty much right back where we started with OpenAPI. You can generate a client (or a server) from this YAML file that a lot of frameworks can generate for you from your code, and the file also describes the types. I wouldn't say it is much simpler though, the schemas can get super complicated (as can configuring the darn API Gateway people inevitably think is necessary).