Is it possible to extract the original headers from a worker fetch request to an end-point which returns a 302? e.g. const res = await fetch("http://localhost:3000/", { "redirect": "manual" }) res = {"body":{},"bodyUsed":false,"headers":{},"url":"http://localhost:3000/","redirected":false,"ok":false,"statusText":"Found","status":302} If I run the same request via curl I get the original headers (e.g. location + set-cookie): curl -v http://localhost:3000/ < HTTP/2 302 < cache-control: private < location: https://www.google.com < set-cookie: SIGNIN.REQUEST=1683699853; path=/; secure; HttpOnly < access-control-expose-headers: Request-Context < date: Tue, 09 May 2023 14:49:59 GMT < content-length: 0 Is it possible to extract the original headers using Cloudflare workers (or any other Cloudflare service)? The main problem is that the set-cookie header is lost.

The headers shouldn't be lost - where are you seeing that? If you're only looking at the log of

res

, you won't see headers due to how that gets serialised

I agree, but they are. The 302 response object only contains following properties.

{"body":{},"bodyUsed":false,"headers":{},"url":"http://localhost:3000/", "redirected":false,"ok":false,"statusText":"Found","status":302}

Where is that log from? Headers being empty is a misnomer - it’s not actually empty. That’s a result of how things get serialised for logs.

Thanks! It worked with Object.fromEntries(res.headers.entries()), but console.log("Headers", JSON.stringify(res.headers.entries())) contains nothing

Yep entries is an iterator so you have to consume it first, then you can log it 😀

Many thanks James! You saved my day 🙂

Happy to help!