[BUG] Claude Code OAuth Authentication Failure

[pvdb]

Preflight Checklist

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

What's Wrong?

Trying to claude login on a fresh Claude Code installation, but an "Unable to access Claude Code" error occurs immediately on the OAuth authorization page in the browser (https://claude.ai/oauth/authorize?...) preventing any authentication.

What Should Happen?

When running claude auth login, the OAuth authorization page at https://claude.ai/oauth/authorize should:

1. Load successfully without errors
2. Display the Claude authentication interface
3. Allow user to authenticate with their Claude.ai credentials
4. Redirect back to Claude Code with a valid authorization code
5. Complete the OAuth flow and establish an authenticated session
6. The user should then be able to use Claude Code normally with their authenticated account.

Error Messages/Logs

Steps to Reproduce

Environment:

• macOS and Alpine Docker (fresh container)
• Multiple browsers tested (regular and incognito)
• Different networks tested

Steps Taken:

• claude auth logout and claude auth login
• Completely removed ~/.claude directory
• Full uninstall/reinstall of Claude Code
• Tested in fresh Alpine Docker container (no pre-existing config)
• Manual URL copy method (pressing 'c') attempted
• Verified other https://claude.ai/ pages work normally
• Repeatedly logged out and logged back into my Anthropic "team" account on claude.ai

Key Details:

• Error appears immediately on OAuth page, before any authentication or callback
• Not a network connectivity issue (other claude.ai pages accessible)
• Not a local configuration issue (reproduced in clean Docker environment)
• Error occurs at the OAuth service level, not during callback/redirect
• Expected: OAuth authorization page should allow authentication and redirect back to Claude Code
• Actual: Immediate "Unable to access Claude Code" error on authorization page itself
• This appears to be a service-side OAuth endpoint issue requiring engineering investigation.

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

No response

Claude Code Version

2.1.114 (Claude Code)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

iTerm2

Additional Information

More details in Conversation ID with Fin AI Agent: 215473969648373

[github-actions]

Found 3 possible duplicate issues:

1. [BUG] Unable to access Claude Code after successful OAuth login with Google account #19280
2. [BUG] Oauth Error - stuck, massive workload, can't log in :( #48659
3. [BUG] OAuth login fails with "Internal server error" (status 500) on Windows — Claude Max subscription #44725

This issue will be automatically closed as a duplicate in 3 days.

• If your issue is a duplicate, please close it and 👍 the existing issue instead
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🤖 Generated with Claude Code

[pvdb]

Found 3 possible duplicate issues:

The observed behaviour and the error messages are different from these other issues so this doesn't appear to be a duplicate, but we'll give the workarounds in #19280 a try to see if they sort things out! 🤞

[pvdb]

Despite some superficial differences, it turns out this was a duplicate of #19280 after all ... closing this ticket!

[github-actions]

This issue has been automatically locked since it was closed and has not had any activity for 7 days. If you're experiencing a similar issue, please file a new issue and reference this one if it's relevant.