Does anyone know to how to setup swagger doc when using duct ?

You'll probably want to use reitit, instead of ataraxy

you mean ataraxy is not working with swagger ?

afaik ataraxy doesn't have swagger support

Unless you set it up manually, but I don't have experience with that

Reitit has built-in swagger support

how about pedestal?

Never used that, sorry. There is a duct module for it though https://github.com/lagenorhynque/duct.module.pedestal

seems like duct template only support ataraxy router

There is a duct reitit router: https://github.com/yannvanhalewyn/duct-reitit

Thanks, I will give it a try