NextAuth v5 `TypeError: next_dist_server_web_exports_next_request__WEBPACK_IMPORTED_MODULE_0__ is not a constructor`

[chungweileong94]

Environment

System:
    OS: macOS 14.3
    CPU: (8) arm64 Apple M2
    Memory: 2.59 GB / 16.00 GB
    Shell: 5.9 - /bin/zsh
Binaries:
    Node: 18.19.0 - ~/Library/Caches/fnm_multishells/18527_1707202116497/bin/node
    Yarn: 1.22.21 - ~/Library/Caches/fnm_multishells/18527_1707202116497/bin/yarn
    npm: 10.2.3 - ~/Library/Caches/fnm_multishells/18527_1707202116497/bin/npm
    pnpm: 8.14.1 - ~/Library/Caches/fnm_multishells/18527_1707202116497/bin/pnpm
    bun: 1.0.26 - /opt/homebrew/bin/bun
Browsers:
    Safari: 17.3
npmPackages:
    next: 14.0.4 => 14.0.4 
    next-auth: 5.0.0-beta.8 => 5.0.0-beta.8 
    react: ^18 => 18.2.0

Reproduction URL

https://github.com/chungweileong94/nextauth-route-handler-error

Describe the issue

If one of the AUTH_URL and NEXTAUTH_URL is set, we will get the following error.

TypeError: next_dist_server_web_exports_next_request__WEBPACK_IMPORTED_MODULE_0__ is not a constructor

How to reproduce

1. Clone the repro
2. Run the app via pnpm dev
3. Navigate to http://localhost:3000/api/auth/signin

Expected behavior

It should show the next-auth built-in sign-in page. Instead, it shows throw 500 error (TypeError: next_dist_server_web_exports_next_request__WEBPACK_IMPORTED_MODULE_0__ is not a constructor)

[chungweileong94]

The problem seems to be caused by new NextRequest(...) in reqWithEnvURL

next-auth/packages/next-auth/src/lib/env.ts

Line 11 in 8a2ca6b

return new NextRequest(href.replace(origin, envOrigin), req)

Which is why setting either AUTH_URL or NEXTAUTH_URL will bypass the problem.

[CogitoBurrito]

I can confirm this bug, same setup

[balazsorban44]

Related to #9795. This sounds like an upstream Next.js bug which I thought has been fixed. Will have a look there. The workaround is to patch new NextRequest to new NextRequest.default for now, or drop the env variables.

Note: You most likely don't need AUTH_URL or NEXTAUTH_URL anyway, it's not been required for a very long time, unless you want a custom path for your auth route, or behind a proxy.

[chungweileong94]

Note: You most likely don't need AUTH_URL or NEXTAUTH_URL, it's not been required for a very long time, unless you want a custom path for your auth route, or behind a proxy.

Ah, good to know.

[balazsorban44]

Fix is on the way in Next.js vercel/next.js#61721

[chungweileong94]

Will close this issue, as it has been fixed in the latest NextJS canary release.

[Zelzazor]

Note: You most likely don't need AUTH_URL or NEXTAUTH_URL anyway, it's not been required for a very long time, unless you want a custom path for your auth route, or behind a proxy.

Thing is, I do use a proxy because I am working with a Docker container and using nginx to deploy the app. What are my options in this case?

EDIT: Nevermind my message, I was able to make the auth work using NEXTAUTH_URL_INTERNAL instead.

[itskaransingh]

Hi @Zelzazor , can you please tell me how you were able to make the auth work using NEXTAUTH_URL_INTERNAL, thanks.

[irclausen]

Hi @Zelzazor , can you please tell me how you were able to make the auth work using NEXTAUTH_URL_INTERNAL, thanks.

I was able to apply a fix for local dev at least by changing:

AUTH_URL=***********

to

NEXTAUTH_URL_INTERNAL=***********

in my .env file. If you don't have AUTH_URL perhaps add NEXTAUTH_URL_INTERNAL instead of replacing