[BUG]

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?

Chrome Native Host crashes on Windows 10 with Bun internal assertion failure

Environment

• Claude Code version: 2.1.84
• OS: Windows 10 Pro 10.0.19045 (x64)
• Chrome: Latest stable with Claude extension v1.0.64
• Shell: Git Bash (MINGW64)

Description

The Chrome integration native messaging host (claude --chrome-native-host) crashes immediately on startup with a Bun internal assertion failure. This prevents the Claude in Chrome extension from connecting to Claude Code.

The /chrome menu shows Status: Enabled and Extension: Installed, but all mcp__claude-in-chrome__* tool calls fail with "No Chrome extension connected."

Crash Report URL

https://bun.report/1.3.11/e_1759ce80EkgggC+pl/M+mx6G6s2joB0vv9nB__64i/5CA0eNrzzCtJLcpLzFFILC5OLSrJzM9TSEvMzCktSgUAiSkKPg

Verified Configuration

The native messaging host chain is correctly set up:

• Registry key HKCU\Software\Google\Chrome\NativeMessagingHosts\com.anthropic.claude_code_browser_extension points to manifest JSON
• Manifest JSON at C:\Users\pc\AppData\Roaming\Claude Code\ChromeNativeHost\com.anthropic.claude_code_browser_extension.json points to bat file
• Bat file at C:\Users\pc\.claude\chrome\chrome-native-host.bat runs claude.exe --chrome-native-host
• Extension ID fcoeoabgfenejglbffodgkkbkcdhcgfn matches allowed_origins in manifest
• The named pipe \\.\pipe\claude-mcp-browser-bridge-pc is never created because the process crashes before that

Actual Behavior

The native host crashes with a Bun v1.3.11 internal assertion failure immediately after attempting to create the socket listener. The named pipe is never created, so Chrome cannot connect.

What Should Happen?

Expected Behavior

The native host should start successfully, create the named pipe, and allow the Chrome extension to connect.

Error Messages/Logs

Steps to Reproduce

Steps to Reproduce

1. Install Claude Code 2.1.84 on Windows 10
2. Install Claude extension (v1.0.64) in Chrome
3. Run claude --chrome
4. Run /chrome - shows Status: Enabled, Extension: Installed
5. Any browser tool call fails with "No Chrome extension connected"

Manually running the native host shows the crash:

$ "C:\Users\pc\.local\bin\claude.exe" --chrome-native-host

[Claude Chrome Native Host] Initializing...
[Claude Chrome Native Host] Creating socket listener: \\.\pipe\claude-mcp-browser-bridge-pc
============================================================
Bun v1.3.11 (759ce802) Windows x64 (baseline)
Windows v.win10_cu
CPU: sse42 avx avx2
Args: "C:\Users\pc\.local\bin\claude.exe" "--chrome-native-host"
Features: Bun.stdin(2) jsc standalone_executable
Builtins: "bun:main" "node:async_hooks" "node:buffer" "node:child_process" "node:crypto" "node:fs" "node:fs/promises" "node:net" "node:os" "node:path" "node:path/win32" "node:process" "node:stream" "node:timers/promises" "node:url" "node:util"
Elapsed: 126ms | User: 78ms | Sys: 62ms
RSS: 0.32GB | Peak: 0.32GB | Commit: 0.47GB | Faults: 78020 | Machine: 42.87GB

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

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.84

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Cursor

Additional Information

_No response_