Vercel NextJS with-supabase example does not work with latest node20 runtime

[chrisui]

Bug report

• I confirm this is a bug with Supabase, not with my own application.
• I confirm I have searched the Docs, GitHub Discussions, and Discord.

Describe the bug

Node fetch failure when trying to use auth api.

TypeError: fetch failed
    at node:internal/deps/undici/undici:12502:13
    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
    at async ah (/var/task/apps/www/.next/server/chunks/125.js:1:75941)
    at async au (/var/task/apps/www/.next/server/chunks/125.js:1:75685)
    at async aP.signInAnonymously (/var/task/apps/www/.next/server/chunks/125.js:1:86849)
    at async P (/var/task/apps/www/.next/server/app/quiz/hair-type/page.js:1:5165)
    at async /var/task/node_modules/.pnpm/[email protected]_@[email protected][email protected][email protected]/node_modules/next/dist/compiled/next-server/app-page.runtime.prod.js:16:418
    at async rP (/var/task/node_modules/.pnpm/[email protected]_@[email protected][email protected][email protected]/node_modules/next/dist/compiled/next-server/app-page.runtime.prod.js:15:7978)
    at async r5 (/var/task/node_modules/.pnpm/[email protected]_@[email protected][email protected][email protected]/node_modules/next/dist/compiled/next-server/app-page.runtime.prod.js:18:1139)
    at async es (/var/task/node_modules/.pnpm/[email protected]_@[email protected][email protected][email protected]/node_modules/next/dist/compiled/next-server/server.runtime.prod.js:16:26320) {
  [cause]: Error: connect ECONNREFUSED 127.0.0.1:54321
      at TCPConnectWrap.afterConnect [as oncomplete] (node:net:1606:16)
      at TCPConnectWrap.callbackTrampoline (node:internal/async_hooks:130:17) {
    errno: -111,
    code: 'ECONNREFUSED',
    syscall: 'connect',
    address: '127.0.0.1',
    port: 54321
  }
}

To Reproduce

Steps to reproduce the behavior, please provide code snippets or a repository:

Following the guide to use the next boilerplate and create a project with supabase auth. only change I made was to use supabase.auth.signInAnonymously within a server action.

I deployed to vercel (where default runtime is the latest, node20) and encountered the error. Tore my hair out for a while wondering if I was missing env (particularly because I saw the 127.0.0.1 portion but I think a bit of a red herring in the end) and eventually tried to downgrade the runtime to node18 and redeploy. It worked.

https://vercel.com/templates/next.js/supabase

Expected behavior

No error when using node 20.

System information

• OS: [e.g. macOS, Windows]
• Browser (if applies) [chrome
• Version of supabase-js: "@supabase/ssr": "^0.4.0", "@supabase/supabase-js": "^2.45.0",
• Version of Node.js: 20

Additional context

The vercel template page says to report any issues here.

[encima]

Thanks for opening, can you confirm this is only occurring with node 20 and not node 22?

Also, fetch has changed a bit between 20 and 21 but you can use a custom fetch implementation (see here). Could you test using a different fetch implementation and report back?

[chrisui]

Hey @encima, unfortunately this can't be confirmed because the issue is encountered when deployed to Vercel which is running on AWS Lambda which only supports node.20x/18x/16x runtimes and not yet 22.

[encima]

Hi @chrisui

No worries, you can use a custom fetch implementation in that case. Let me know if it doesn't work and we can reopen :)