[BUG] Google OAuth on Desktop and web routes paid subscriber to new-account onboarding; support ticket unanswered since May 19

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Preflight Checklist

• [x] I have searched existing issues — this matches the failure mode in #51002 and #57164, but this is my own unresolved case requiring escalation
• [x] This is a single bug report
• [x] I am a paying Claude subscriber affected by this issue

I am opening this on this repo per the precedent in #51002 and #57164, where account/auth issues required engineering escalation because Fin AI support and email support could not resolve them.

What's Wrong

Clicking "Continue with Google" in the Claude Desktop app on macOS, and on claude.ai in any browser (Safari, Chrome, incognito included), completes Google authentication successfully but then drops me on the new-user onboarding flow ("Let's create your account") with my email shown as verified — instead of authenticating into my existing paid account.

The Claude mobile app on the same Google identity remains fully signed in and functional, with the active paid plan visible. This confirms the account exists, the subscription is active and billing, and only the Desktop/web OAuth handoff is broken.

I have deliberately NOT clicked "Create account", to avoid creating a duplicate account under a different auth provider, as documented in #51002.

Steps to Reproduce

1. Have an existing paid Claude subscription originally created via Continue with Google
2. Be signed in on the Claude mobile app on the same Google identity (works fine)
3. Open Claude Desktop on macOS, or claude.ai in a fresh browser session
4. Click "Continue with Google" and complete authentication
5. Observe: routed to onboarding / "Let's create your account" instead of the account dashboard

Expected Behavior

"Continue with Google" with a Google identity that maps to an existing paid account should authenticate into that account.

Actual Behavior

Routed to new-user onboarding on Desktop and web. Mobile session unaffected.

What I Have Already Tried

• Cleared cookies/cache; tested in private/incognito windows
• Multiple browsers (Safari, Chrome)
• Signed out of all other Google accounts
• Revoked and re-granted Anthropic/Claude permissions at myaccount.google.com/permissions
• Fully signed out of Claude Desktop, quit, reopened
• Fin AI support via Help Center — unresolved
• Detailed email report to support sent May 19, 2026 — no human response as of June 10
• Follow-up email sent June 10 — pending6

Timeline

• Issue present for ~2 months
• Support contacted May 19, 2026 — no response for over 3 weeks
• Billed in full throughout, with no Desktop or web access
• Conversation ID for your records: 215474365384436

Request

1. Urgent (individual case): route to a human Product Support specialist who can inspect the server-side account record, verify the Google OAuth identity mapping to my existing paid account, and repair it so Desktop/web login works.
2. Product fix (broader): the OAuth callback should never silently fall through to new-user onboarding when the Google identity matches a billed existing account (same request as #57164).

Verification

I can provide privately via official support channels (not in this public issue): filipkos79@gmail.com

<img width="1280" height="800" alt="Image" src="https://github.com/user-attachments/assets/586cfb79-28ce-4e1f-abfd-69e9ccc236e5" />
<!-- Failed to upload "Screenshot 2026-05-19 at 15.55.34.jpeg" -->

<img width="1280" height="800" alt="Image" src="https://github.com/user-attachments/assets/afefd539-0929-4268-9bea-c08be5e1803c" />
<img width="1179" height="2556" alt="Image" src="https://github.com/user-attachments/assets/233c6521-f0ca-44e5-b907-5941a6b69491" />

mobile screenshots showing the active paid pro plan and signed-in session alongside the Desktop onboarding screen.
Conversation ID for your records:
215474365384436

What Should Happen?

1. Urgent (individual case): route to a human Product Support specialist who can inspect the server-side account record, verify the Google OAuth identity mapping to my existing paid account, and repair it so Desktop/web login works.
2. Product fix (broader): the OAuth callback should never silently fall through to new-user onboarding when the Google identity matches a billed existing account (same request as #57164).

Error Messages/Logs

Steps to Reproduce

Steps to Reproduce

1. Have an existing paid Claude subscription originally created via Continue with Google
2. Be signed in on the Claude mobile app on the same Google identity (works fine)
3. Open Claude Desktop on macOS, or claude.ai in a fresh browser session
4. Click "Continue with Google" and complete authentication
5. Observe: routed to onboarding / "Let's create your account" instead of the account dashboard

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

new

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_