can't set cookie in custom local domain

I setting cookie using FastApi

response.set_cookie(key="rf_t", value=access_token, httponly=False, expires=120)

And its works perfect on "localhost:<any_port>" local domain

but I need subdomains and cross subdomain cookies so I found out you can change hosts file at \Windows\System32\Drivers\etc\hosts

and created couple of domains with subdomains like so: shop.localhost
  • and cookie doesn't set for all of them, JSON responses come from server, but cookie doesn't set, it only sets when I'm using basic localhost domain

im using vue 3 vite on front, and setting dev domain and port in vite.config.js like so

server: {
    port: 5000,
    host: "shop.localhost"

I guess it has something to do with chrome policy, because its not https, but is there any way I can use local subdomains, and be able to set cross cookies (or any cookies) for them?

Thanks you a lot my fellow developers!


  • Setting api server host to the same local domain ( as front (, made it work! shout-out to @Chris

    For further details, please have a look at the following answers:

    1. Cookie is not created when calling the endpoint in FastAPI
    2. FastAPI is not returning cookies to React frontend
    3. How to redirect from one domain to another and set cookies or headers for the other domain?