I'm trying to set up a solution for maintaining an OpenAPI document for a new Next.js app that uses App Router without seperatly maintaining type definitions and documentation.

It looks like it would be possible for a tool to statically analyse route.ts files with well typed handler functions and generate a good OpenAPI spec document. Is there a tool that's well known to do this and I'm just failing to find it?

Suggestions for another approach?

Thanks for your help!

I'm brand new to Next.js but not React/TS/Zod/OpenAPI.