React doesn't keep or send cookies to Node?

Question

I have a Node app with this simplified API that checks if user is authenticated (with session):

export default (req, res,) => {
  if (!req.session || !req.session.loggedIn) {
    return res.status(401).send();
  }
  return res.status(200).send();
};

In Postman everything works well, but when React client makes this request:

axios.get(`${domain}/is-auth`)
  .then((res) => {
    return res.status === 200;
  })
  .catch((err) => {
    throw err;
  });

... it always gets 401 and return false. The server can't see its session. I am reading it's about cookies but aren't cookies supposed to be kept and sent by browser automatically? If not then how I can do that? Please help.

Answer 1

fetch and axios indeed do not send credentials automatically with the request, you will have to specify it by setting the "withCredentials" option to true:

axios.get(`${domain}/is-auth`, { withCredentials: true })
  .then((res) => {
    return res.status === 200;
  })
  .catch((err) => {
    throw err;
  });