Pages Router does not use updated cookies from Proxy `response.cookies.set()`, unlike App Router

[thomasboyt]

Link to the code that reproduces this issue

https://github.com/thomasboyt/nextjs-broken-pages-router-proxy-cookies-behavior

To Reproduce

1. next dev
2. Visit localhost:3000/app-demo. Notice that the new cookie value is displayed correctly in the rendered component.
3. Clear your cookies.
4. Visit localhost:3000/pages-demo. Notice that the new cookie value is not displayed correctly.
5. Refresh. Notice the new cookie value is now displayed correctly.

Current vs. Expected behavior

The Pages Router should support the same behavior as App Router, as implemented in #65008: setting cookies using response.cookies.set() should show the new cookie values in ctx.req.cookies in getServerSideProps, as they show up in next/headers's cookies() function in App Router.

Otherwise, the documentation on https://nextjs.org/docs/pages/api-reference/file-conventions/proxy#using-cookies should be updated to indicate this is expected to not work in Pages Router.

Provide environment information

Operating System:
  Platform: darwin
  Arch: arm64
  Version: Darwin Kernel Version 25.3.0: Wed Jan 28 20:48:41 PST 2026; root:xnu-12377.81.4~5/RELEASE_ARM64_T6041
  Available memory (MB): 49152
  Available CPU cores: 16
Binaries:
  Node: 22.22.0
  npm: 10.9.4
  Yarn: N/A
  pnpm: N/A
Relevant Packages:
  next: 16.2.0-canary.51 // Latest available version is detected (16.2.0-canary.51).
  eslint-config-next: N/A
  react: 19.2.3
  react-dom: 19.2.3
  typescript: 5.9.3
Next.js Config:
  output: N/A

Which area(s) are affected? (Select all that apply)

Pages Router, Middleware

Which stage(s) are affected? (Select all that apply)

next dev (local), next start (local)

Additional context

This is blocking an incremental rewrite of my application in App Router. My application heavily used getServerSideProps and set various cookies in its logic. I am trying to move the logic that was used for all requests to proxy.ts, as App Router does not allow setting cookies during server-side rendering. Unfortunately, right now I cannot rely on proxy.ts cookie setting to work correctly in Pages Router.

I may have to implement a manual workaround using headers added to the request.

[icyJoseph]

Hi,

I guess there's some DX friction there. In the headers coming to the Pages Router page, we can see;

  'set-cookie': 'test-cookie=test%201%202%203; Path=/',

So it is there. And it makes sense, setting on the client, is done via a set-cookie header on the downstream response. I can imagine that for App Router, since you likely want to see that cookie while rendering, it was picked up from the set-cookie and made available in the cookie store. I am pretty sure I've seen some issue reports about this (that are now resolved), because otherwise, the safe way to go about this, is to be explicit, and do something like this in the proxy file.

  request.cookies.set("test-cookie", "test 1 2 3");

  const resp = NextResponse.next({
    request,
  });

  // and also set it in the downstream `resp` cookies
  resp.cookies.set("test-cookie", "test 1 2 3");

Now the Pages Router will see the cookie. I think to unblock yourself from migration this might be good enough.

[thomasboyt]

Interesting, I do think that unblocks me as it works if I add it to the reproduction demo. Thanks so much for a quick response on that!

However, I still think this is a pretty major documentation bug, at a minimum, due to the difference in behavior:

• In App Router, all you have to do is response.cookies.set(), and the SSR logic that runs after proxy.ts will see the new cookie in the list returned from cookies().
• In Pages Router, you must additionally do request.cookies.set() for ctx.req.cookies to be updated.

Additionally, I think the App Router and Pages Router documentation for interacting with cookies is generally a bit confusing:

• https://nextjs.org/docs/app/api-reference/file-conventions/proxy#using-cookies
• https://nextjs.org/docs/pages/api-reference/file-conventions/proxy#using-cookies

Neither of these explain the differences in behavior between the request and response cookie objects. Crucially, the Pages Router documentation doesn't mention anything about having to pass the updated request object into NextResponse.next() for cookies. This is directly mentioned as required for headers here: https://nextjs.org/docs/app/api-reference/file-conventions/proxy#using-cookies

Honestly, I don't understand why in either case you'd be required to do this - is the request object passed to proxy() supposed to be treated as read-only?

Either way, I'd be happy to contribute to the docs now that I've had some clarifications on the expected behavior, I don't think it'd take much to clean up that section. It looks like both the Pages Router doc and App Router doc are generated from the same source, so can probably just document setting the response cookie for App Router and then add a caveat that you must also set the request for Pages Router.

[icyJoseph]

Right, give it a go. I'll try to unearth some issues/PRs, because I remember that some DX improvements were made around this. It might be that the layer that passes the cookies into gSSP and others in Pages Router was not patched.

Edit: #65008, #65820, #67924, #67956

[darshjme-codes]

Triage: Middleware cookie updates not reflected in Pages Router → likely middleware execution order issue