[macOS] Codex login redirects to /add-phone after successful Authenticator MFA

What version of the Codex App are you using (From “About Codex” dialog)?

26.803.81509

What subscription do you have?

ChatGPT Pro 20x

What platform is your computer?

Darwin 24.6.0 arm64 arm

What issue are you seeing?

I cannot sign in to Codex using my existing ChatGPT account because the authentication flow redirects to auth.openai.com/add-phone after I successfully complete email/password authentication and Authenticator MFA.

My existing ChatGPT account has been working normally for more than six months. I accidentally signed out of the Codex/ChatGPT desktop app, and since then I have been unable to sign back in.

The important part is that the account itself is valid and the existing MFA configuration works correctly:

• I can sign in successfully to ChatGPT on the web.
• I tested this using a completely new browser with no existing ChatGPT session.
• I used the same Outlook email address and password.
• I successfully completed the same Authenticator app MFA challenge.
• The web login completes successfully without asking for a phone number.

However, the same account cannot complete authentication through Codex.

Both of the following clients reproduce the problem:

1. ChatGPT/Codex desktop app on macOS
2. Codex CLI

In both cases, email/password authentication succeeds, Authenticator MFA succeeds, and then the authentication flow redirects to:

https://auth.openai.com/add-phone

The page says:

Phone number required Add your phone number to continue. We'll send a one-time code to verify it.

I do not have a phone number that I can provide for this account, so there is no way to continue.

This appears to be an authentication-flow issue rather than an MFA failure. The existing Authenticator factor is successfully verified before the /add-phone step.

What steps can reproduce the bug?

Web login — control test

1. Open a completely new browser/profile with no existing ChatGPT session.
2. Open ChatGPT.
3. Sign in using the existing Outlook email address and password.
4. Complete the Authenticator app MFA challenge.
5. The login succeeds and the existing ChatGPT account is available.
6. No phone number is requested.

ChatGPT/Codex desktop app

1. Open the ChatGPT desktop app on macOS (the app formerly known as Codex).
2. Sign out of the existing account.
3. Start the login flow again.
4. The app opens the OpenAI authentication page in the browser.
5. Enter the same Outlook email address and password.
6. Complete the Authenticator app MFA challenge successfully.
7. Instead of completing the OAuth flow and returning to the desktop app, the browser redirects to:

https://auth.openai.com/add-phone

1. The authentication flow is blocked because a phone number is required.

Codex CLI

The same issue can be reproduced with the Codex CLI:

1. Run codex login.
2. The CLI opens the OpenAI OAuth authorization page.
3. Sign in using the same Outlook email address and password.
4. Complete the same Authenticator MFA challenge successfully.
5. The flow redirects to:

https://auth.openai.com/add-phone

1. The CLI login cannot complete.

The Codex CLI OAuth request identifies itself with:

• originator=codex-tui
• codex_cli_simplified_flow=true
• redirect_uri=http://localhost:1455/auth/callback

This suggests that the problem is occurring in the Codex-specific OAuth/authentication flow rather than in the local desktop application.

Work impact

This issue is currently seriously affecting my work.

I use Codex as part of my daily development workflow, and both the Codex desktop app and Codex CLI are currently inaccessible because of this authentication issue.

I am a ChatGPT Pro 20x subscriber, and the problem prevents me from using the Codex functionality associated with my existing paid subscription.

This is not simply a minor inconvenience or a preference issue: I am currently unable to use Codex for my normal development work.

What is the expected behavior?

After successfully authenticating with:

1. Email + password
2. Existing Authenticator MFA

the Codex desktop app and Codex CLI should complete the OAuth login and authenticate the existing ChatGPT account.

A phone enrollment step should not be required when the existing account can already authenticate successfully through ChatGPT web using the same credentials and existing MFA factor.

Expected flow:

Email + password
↓
Authenticator MFA
↓
OAuth authorization
↓
Codex login succeeds

Actual flow:

Email + password
↓
Authenticator MFA succeeds
↓
/add-phone
↓
Phone number required
↓
Cannot continue

Additional information

• The account has been used normally for more than six months.
• The problem started immediately after I accidentally signed out of the Codex/ChatGPT desktop app.
• The same account continues to work normally on ChatGPT web.
• Web login was tested in a completely new browser with no existing ChatGPT cookies/session.
• The same email address, password, and Authenticator MFA method were used for both web and Codex authentication.
• The network environment has been stable and uses the same fixed IP address that I have been using for a long time.
• This is not an incorrect MFA code or failed MFA challenge. The Authenticator challenge succeeds before the /add-phone redirect.
• I do not have a phone number to use for the phone enrollment step.

The final URL is:

https://auth.openai.com/add-phone

This appears to be similar to the authentication-flow issue reported in #34934, but my account uses an Authenticator app as the existing MFA factor and does not have a phone number.

Could you please check why the Codex OAuth flow is requiring phone enrollment after successful authentication with an existing Authenticator MFA factor?