[BUG] Chrome native host crashes with Bun "Internal assertion failure" on Windows 11

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?

The Chrome browser integration fails to connect. Running /chrome shows "Reconnect successful" but the status bar
shows "1 mcp error" and attempting to use browser tools returns "The Claude browser extension isn't connected."

Environment:

• OS: Windows 11
• Claude Code version: 2.1.29
• Chrome extension: Installed and enabled
• Shell: Git Bash / MINGW64

The native messaging host crashes immediately on startup:

$ "C:/Users/jasre/.local/bin/claude.exe" --chrome-native-host

[Claude Chrome Native Host] Initializing...
[Claude Chrome Native Host] Creating socket listener: \\.\pipe\claude-mcp-browser-bridge-jasre

panic(main thread): Internal assertion failure
oh no: Bun has crashed. This indicates a bug in Bun, not your code.

Configuration verified working:

• Registry: HKCU\Software\Google\Chrome\NativeMessagingHosts\com.anthropic.claude_code_browser_extension points to

correct JSON

• JSON manifest: C:\Users\jasre\AppData\Roaming\Claude

Code\ChromeNativeHost\com.anthropic.claude_code_browser_extension.json

• Batch file: C:\Users\jasre\.claude\chrome\chrome-native-host.bat exists and calls claude.exe

--chrome-native-host

• claude.exe exists at expected path

Troubleshooting attempted:

• Verified Chrome is running
• Verified extension version
• Uninstalled separate system Bun installation (was v1.3.7) - crash persists
• claude update confirms latest version

What Should Happen?

Claude should connect to Chrome Extension and execute commands against given web pages

Error Messages/Logs

Crash details:
  - Embedded Bun version: 1.3.5
  - Crash report URL: https://bun.report/1.3.5/e_11e86cebEugggC++08F+mvBoxhkf0389e__0shkwCA0eNrzzCtJLcpLzFFILC5OLSrJ
  zM9TSEvMzCktSgUAiSkKPg
  - Crash occurs when creating the named pipe for browser communication

Steps to Reproduce

1. Run claude --chrome
2. Run /chrome and select "Reconnect extension"
3. Observe "1 mcp error" in status bar
4. Attempt any browser tool - fails with extension not connected

Claude Model

Opus

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.29

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

_No response_