My project is set up with supabase + supabase auth. I’ve been back and forth developing in v0 and locally. But now i have authentication implemented and in v0 i cant seem to get it working. I gotta open in a new tab.
To be clear, I implemented the auth myself. Not with v0. I’m just trying to continue to iterate on features (not related to auth) within v0.
Thanks in advance!
GPT5 says (I think its pretty convincing):
The v0 / Vercel warning is not a bug in your code, but a limitation of the embedded preview:
The embedded preview runs inside an
iframewith security restrictions (cookies, storage, redirects, OAuth).
When v0 detects authentication libraries (Supabase Auth, NextAuth, Clerk, Auth.js, etc.), it correctly assumes that:
Login will not work properly inside the iframe
Cookies (SameSite), redirects, and window.location may fail
That’s why it shows:
“Found authentication libraries used in the generated code, which might not work as expected in the embedded preview”
When working with routes like:
/auth/login
/auth/callback
any session-based flow
Always use “Open in New Tab”.
In that context:
There is no iframe
The browser behaves normally
The warning disappears
Behavior matches production
This is the approach recommended by Vercel.
have a read over this. might help
Yeah I use Supabase in v0 every day. Just use the auth installation prompt and it’ll set it all up for you! Thanks for the tage @heystu
did that work @agnelnieves ?
I’m experiencing exactly the same issue discussed here with Supabase Auth in v0.
In the embedded preview, I constantly get the banner:
“Browser Restriction Detected , Found authentication libraries used in the generated code, which might not work as expected in the embedded preview due to browser restrictions. To see the preview, open in a new tab.”
This makes it impossible to properly test authentication inside v0 itself, and breaks the development workflow. Opening everything in a new tab every time isn’t a viable long-term solution when building serious projects.
I also want to say that I genuinely understand how much work must have gone into the new version of the platform, and I really appreciate the ambition behind it. v0 has honestly been the best AI-assisted development platform I’ve used compared to alternatives like Bolt or Lovable — which is exactly why this situation is frustrating.
Right now though, the fact that the old v0 can no longer be used to create new projects, while the new version still has major blockers like this, puts users in a very difficult position. On my side, it’s currently preventing production-level development.
I say this respectfully, but transparently: if this isn’t addressed soon, it risks pushing many users toward competing tools — and I’m personally starting to consider that as well, which is unfortunate because I’d much rather keep building with v0.
I hope the moderators and the v0/Vercel team can escalate this internally and let us know whether a fix or workaround is coming. Thanks for looking into such an important issue.
Hey! You are doing everything right. However since the new release v0 has build in this warning on all kind of auth routes/methodes. To be 100% sure that auth works the way you want it, you are now being “forced” to open a new normal tab. I agree with you that this action maybe feels a bit weird and maybe even bad, but when developing the best way is to work with 2 screens or splitscreens and put v0 chat left and on the second screen the new tab. And yes this way you are not able to use the design tool i think.
@pawlean you know anything about bringing back the design mode for apps with a auth connection?
Cheers,
MarnixB
thank you. But this way doesn’t allow “fix free by v0”.
Did you have any luck with the prompt from Aaron.
I use the same prompt and it makes a world of difference honestly. another trick is to just give the chat the link to the specific Supabase docs regarding the auth area you are having issues with. I ran into some auth issues a while ago around password resetting via email, I simply gave the v0 chat the link to that specific doc section, and told it to create per the guidelines. Sorted it out in one go!
let us know if your issue is resolved or in need or more help.
Getting Design Mode back is currently being worked on. It will stil work in older “pre update” chats, but current beta chats you just have to sit tight for a bit without design mode. But it is coming.
Thanks a lot for the tips and the update, really appreciate you taking the time to reply, and thanks to the v0 team for listening to users. I’ll try the Supabase docs approach and see if that helps.
Good to hear Design Mode is being worked on.
Thanks again for keeping us posted
I See, i hope they also bring back logging to the new beta chats when working with auth… especially for auth stuff logging is really nice to have 
Hey! To help debug your v0 project, could you share your v0 chat link?
It looks like https://v0.app/chat/... — you can copy it from your browser’s address bar while in the chat.
You’ll also need to unlist the chat so our team can view it — here’s how: Sharing | v0 Docs
This helps the team reproduce what you’re seeing much faster. Thanks!
