[BUG] claude --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?

When running claude --chrome-native-host to enable the Chrome extension connection, the native host crashes immediately with a Bun internal
assertion failure. This prevents the Chrome extension from connecting to Claude Code.

Environment:

• OS: Windows 11
• Claude Code version: 2.1.31
• Bun version: 1.3.5
• CPU: x64 with SSE4.2, AVX, AVX2

Actual Behavior:
The native host initializes, creates the socket listener, then immediately crashes:

[Claude Chrome Native Host] Initializing...
[Claude Chrome Native Host] Creating socket listener: \\.\pipe\claude-mcp-browser-bridge-Gabriel
============================================================
Bun v1.3.5 (1e86cebd) Windows x64 (baseline)
Windows v.win11_dt
CPU: sse42 avx avx2
Args: "c:\users\gabriel\.local\bin\claude.exe" "--chrome-native-host"
Features: Bun.stderr(2) Bun.stdin(2) Bun.stdout(2) jsc standalone_executable
Builtins: "bun:main" "node:assert" "node:async_hooks" "node:buffer" "node:child_process" "node:constants" "node:crypto" "node:events"
"node:fs" "node:fs/promises" "node:http" "node:https" "node:module" "node:net" "node:os" "node:path" "node:path/posix" "node:path/win32"
"node:perf_hooks" "node:process" "node:querystring" "node:stream" "node:timers/promises" "node:tls" "node:tty" "node:url" "node:util"
"node:zlib" "node:worker_threads" "undici" "ws" "node-fetch" "node:http2"
Elapsed: 572ms | User: 765ms | Sys: 234ms
RSS: 0.55GB | Peak: 0.55GB | Commit: 0.55GB | Faults: 134160 | Machine: 16.56GB

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

Bun Crash Report:
https://bun.report/1.3.5/e_11e86cebEugggC++08F+mvBoxhkf0389e__0shkwCA0eNrzzCtJLcpLzFFILC5OLSrJzM9TSEvMzCktSgUAiSkKPg

Impact:
The Chrome extension cannot connect to Claude Code, making browser automation features unusable on Windows.

Additional Context:

• The crash happens consistently on every attempt
• Chrome extension shows "Browser extension is not connected" error in Claude Code

What Should Happen?

Expected Behavior:
The native host should start and listen for connections from the Chrome extension.

Error Messages/Logs

[Claude Chrome Native Host] Initializing...
[Claude Chrome Native Host] Creating socket listener: \\.\pipe\claude-mcp-browser-bridge-Gabriel
============================================================
Bun v1.3.5 (1e86cebd) Windows x64 (baseline)
Windows v.win11_dt
CPU: sse42 avx avx2
Args: "c:\users\gabriel\.local\bin\claude.exe" "--chrome-native-host"
Features: Bun.stderr(2) Bun.stdin(2) Bun.stdout(2) jsc standalone_executable 
Builtins: "bun:main" "node:assert" "node:async_hooks" "node:buffer" "node:child_process" "node:constants" "node:crypto" "node:events" "node:fs" "node:fs/promises" "node:http" "node:https" "node:module" "node:net" "node:os" "node:path" "node:path/posix" "node:path/win32" "node:perf_hooks" "node:process" "node:querystring" "node:stream" "node:timers/promises" "node:tls" "node:tty" "node:url" "node:util" "node:zlib" "node:worker_threads" "undici" "ws" "node-fetch" "node:http2" 
Elapsed: 572ms | User: 765ms | Sys: 234ms
RSS: 0.55GB | Peak: 0.55GB | Commit: 0.55GB | Faults: 134160 | Machine: 16.56GB

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

To send a redacted crash report to Bun's team,
please file a GitHub issue using the link below:

 https://bun.report/1.3.5/e_11e86cebEugggC++08F+mvBoxhkf0389e__0shkwCA0eNrzzCtJLcpLzFFILC5OLSrJzM9TSEvMzCktSgUAiSkKPg
Windows v.win11_dt
CPU: sse42 avx avx2
Args: "c:\users\gabriel\.local\bin\claude.exe" "--chrome-native-host"
Features: Bun.stderr(2) Bun.stdin(2) Bun.stdout(2) jsc standalone_executable 
Builtins: "bun:main" "node:assert" "node:async_hooks" "node:buffer" "node:child_process" "node:constants" "node:crypto" "node:events" "node:fs" "node:fs/promises" "node:http" "node:https" "node:module" "node:net" "node:os" "node:path" "node:path/posix" "node:path/win32" "node:perf_hooks" "node:process" "node:querystring" "node:stream" "node:timers/promises" "node:tls" "node:tty" "node:url" "node:util" "node:zlib" "node:worker_threads" "undici" "ws" "node-fetch" "node:http2" 
Elapsed: 572ms | User: 765ms | Sys: 234ms
RSS: 0.55GB | Peak: 0.55GB | Commit: 0.55GB | Faults: 134160 | Machine: 16.56GB

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

To send a redacted crash report to Bun's team,
please file a GitHub issue using the link below:

 https://bun.report/1.3.5/e_11e86cebEugggC++08F+mvBoxhkf0389e__0shkwCA0eNrzzCtJLcpLzFFILC5OLSrJzM9TSEvMzCktSgUAiSkKPg

Steps to Reproduce

Steps to Reproduce:

1. Install Claude Code CLI on Windows 11
2. Install the Claude browser extension in Chrome
3. Run claude --chrome-native-host

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.31

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

VS Code integrated terminal

Additional Information

_No response_