How can I set domain for a cookie?

[Takabrycheri]

Hi, sorry but I'm really new to cookies.
At the moment I only have the value of a cookie to send but now I also have to specify the domain of the cookie, which I didn't need before... but I can't find anything about it.
Could someone please help me?

Thanks in advance

[agammann]

If you're setting the cookie in an aiohttp server response, pass domain to set_cookie before returning the response:

from aiohttp import web

async def handler(request):
    response = web.Response(text="OK")
    response.set_cookie("session", cookie_value, domain="example.com", path="/")
    return response

That produces Set-Cookie: session=...; Domain=example.com; Path=/ (checked with aiohttp 3.14.5). The domain must cover the host serving the response; if the cookie is only for that exact host, omit domain and let it be host-only. If by “send” you mean an aiohttp client request, the browser/client sends a Cookie header containing name/value pairs; Domain is an attribute of the server's Set-Cookie response, not part of the outgoing Cookie header. See StreamResponse.set_cookie.