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# v0 login workaround for "Authentication failed" error in api/auth callback

34 views · 3 likes · 3 posts


rtruxler (@rtruxler) · 2026-01-28 · ♥ 1

A few people (myself included) were reporting auth issues in the `v0` chat. This manifested in the form of a plain text rendering of:

> **Authentication failed**

in an `api/auth` callback.

## Workaround
I was able to login via incognito, then if I went back to my standard Chrome tabs and refreshed the page, I was logged in again. Not sure if this was coincidence or causation (would probably have to be some server-side user profile state if it were causation).

If you’re still stuck in an "Authentication failed" state, my recommendation would be:

1. Look for `v0.dev` cookies.
2. Remove them.
3. Try again.


Sungkhum (@sungkhum) · 2026-01-28 · ♥ 2

I also clicked the “sign-up” button at v0.app and that reset stuff.


Pauline P. Narvas (@pawlean) · 2026-01-29

Hi, @rtruxler!

Just saw your other comment. Hoping this is fixed for you now?