Why cookies are not visible in nodejs headers?

Question

Node.js

After setting the cookie on the server
res.writeHead(200, {'Set-Cookie': 'mycookie'+ Math.round(Math.random()*100)+'=test;path=/;', 'Content- Type': 'text/plain; charset=utf8', 'Access-Control-Allow-Origin': '*'});
On the client I see that the cookie is coming. In subsequent requests, I look in the request.headers node and there are no cookies.
What is the problem?
Thanks in advance.