[BUG] macOS Authentication Loop - "Missing API key · Run /login" endless cycle

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?

• Problem: Claude Code shows "Missing API key · Run /login" repeatedly.

Running /login completes successfully but immediately returns to the same
error message - creating an endless authentication loop.

• Platforms affected: macOS, both local terminal and SSH sessions
• What I've tried:
• Multiple complete reinstalls (npm global, npx, native installer)
• Cleared all caches (npx clear-npx-cache, removed ~/.claude)
• Keychain unlock (security unlock-keychain)
• Different terminal applications
• Various shell configuration changes
• Duration: Issue persists across multiple days/sessions
• Support status: Emailed support days ago with no response
• Impact: Cannot use Claude Code at all due to authentication failure
• Environment:
• macOS version: [macOS Sequoia Version 15.7 (24G222)]
• Claude Code version: [claude-sonnet-4-20250514]

This appears to be the same issue reported in GitHub issues #5515, #5225,
affecting multiple macOS users.

What Should Happen?

• Fix the macOS keychain integration so authentication tokens persist

properly

• Ensure SSH sessions can access stored authentication credentials
• Provide alternative authentication method if keychain integration

cannot be fixed

Error Messages/Logs

Steps to Reproduce

1. Install Claude Code on macOS (any method: npm global, npx, or native

installer)

1. Run claude command in terminal
2. When prompted with "Missing API key · Run /login", type /login
3. Complete the OAuth authentication flow in browser (authentication

succeeds)

1. Return to terminal - still shows "Missing API key · Run /login"
2. Repeat step 3-5 - creates endless loop

Alternative reproduction:

1. SSH into macOS machine with Claude Code installed
2. Run claude command
3. Observe immediate "Missing API key · Run /login" error
4. Follow steps 3-6 above

Expected after step 4: Authentication should persist and Claude Code
should work normally

Actual result: Authentication never persists, requiring infinite
re-authentication attempts

Claude Model

Sonnet (default)

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

1.0.128

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

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