Fix · Supabase and databases

Redirect URL not allowed after sign in or email link

Not checked against the vendor's current screens

What you may see

After clicking the email link I land on localhost or on an error
Google or magic link sign-in returns to the wrong site

Most likely cause

The address the user returns to is not in the project's allowed list, so Supabase falls back to the main Site URL (often still localhost).

Check first (about two minutes)

In the Authentication settings find the URL configuration (Site URL and Redirect URLs).
Check the address in the failing link: which domain does it use?

The fix prompt

What you type here never leaves your browser. The search runs on this page, and nothing is sent to a server or to an AI.

The exact error or what you see

What you did before it happened

Kept only in this browser, on this device. Keys and passwords are removed before anything is saved.

Prompt language

You are a careful senior engineer who knows Supabase (database, login and file storage) and explains it to people who are not developers. I am not a developer, so explain every step in plain words and tell me exactly which button, menu or command you mean. If you are not sure about something, say so; do not guess.

Menu and button names change over time. If you cannot find a button or page I mention, say so and tell me what to look for instead of guessing.

THE PROBLEM
Redirect URL not allowed after sign in or email link

THE EXACT ERROR OR WHAT I SEE
[paste the exact error here]

WHAT I DID BEFORE IT HAPPENED
[write in a few words what you did before it happened]

MOST LIKELY CAUSE
The address the user returns to is not in the project's allowed list, so Supabase falls back to the main Site URL (often still localhost).

DO THESE STEPS, IN THIS ORDER
1. Find in the code where redirect addresses are built (emailRedirectTo, redirectTo, callback routes).
2. Tell me the exact addresses to add to the allowed list: the live domain, the www version, and localhost for development.
3. Set the main Site URL to the live address.
4. Make the code use the current site address, not a hard-coded one.
Stop and tell me if what you see does not match a step. Do not skip ahead.

CHECK THAT IT WORKED
- A new email link returns to the live site and signs me in.
Tell me exactly what I should see on the screen when it works.

DO NOT CHANGE
- Do not allow a wildcard for every address.
- Anything I did not ask about: the design, the text, other pages, other settings or the data.
- Do not delete files, data or branches, do not reset or force-push, and do not rewrite history, unless you first show me exactly what would be lost and I say yes.
- Do not paste, print or ask me to paste a password or secret key into this chat. If one is needed, tell me which settings page of the right service to store it in.

WHEN YOU FINISH
Explain in simple words what you changed (file by file or setting by setting), why you changed it, and how I can undo it.

Paste it into Claude, ChatGPT, Gemini or Cursor, then follow what it says.

After you tried it, did it work?

Steps

Find in the code where redirect addresses are built (emailRedirectTo, redirectTo, callback routes).
Tell me the exact addresses to add to the allowed list: the live domain, the www version, and localhost for development.
Set the main Site URL to the live address.
Make the code use the current site address, not a hard-coded one.

Do not do this

Do not use old links to test; request a new one each time.
Do not allow a wildcard for every address.

Try another entry