We used a forked version of https://github.com/readmeio/oas to help dereference `$ref` statements, but other than that this is entirely hand-written: The Typescript `factory` AST API + `prettier` for formatting.

yeah i was always annoyed how machine like the stubs that it generated are. I did here that they invested on making the go SDK more idiomatic. We've been exploring using templating or taking this approach of writing the generators from scratch in the native language.