[BUG] Claude Cowork doesn't honor MacOS default browser

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?

OS: MacOS Tahoe 26.4.1
Claude Code: Claude 1.6608.0 (f65729) 2026-05-07T14:16:09.000Z

Sign In -> Continue with Google -> Opens Safari
Even though in settings my default browser is set to Firefox.

<img width="372" height="346" alt="Image" src="https://github.com/user-attachments/assets/9e916694-12a6-4f02-ac49-ce7bd155aa5b" />

What Should Happen?

Open Firefox browser for login

Error Messages/Logs

Steps to Reproduce

MacOS Try to login with google while default browser is set to Firefox (can be any other but haven't tried myself)

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

Claude 1.6608.0 (f65729) 2026-05-07T14:16:09.000Z

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_