[BUG] Claude Code Chrome integration doesn't detect extension in Brave 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?

Claude Code's --chrome flag and /chrome command cannot detect the Claude Chrome extension when it's installed in Brave Browser. The extension shows "Not detected" even though:

1. The Claude extension (v1.0.36) is installed and fully functional in Brave
2. The extension can see webpages and respond to user queries in the side panel
3. The extension has "Communicate with cooperating native applications" permission enabled
4. The native messaging host manifest exists in Brave's NativeMessagingHosts directory

The same setup works correctly with Google Chrome - extension is immediately detected as "Installed".

What Should Happen?

Claude Code should detect the Claude Chrome extension when installed in Brave Browser, since:

1. Brave is Chromium-based and uses the same extension APIs
2. The extension installs and functions correctly in Brave
3. The native messaging host manifest can be placed in Brave's directory
4. Many developers use Brave as their primary browser

Error Messages/Logs

**Claude Code `/chrome` output in Brave:**

Status: Enabled
Extension: Not detected

❯ Install Chrome extension
  Enabled by default: No


**Claude Code `/chrome` output in Chrome (working):**

Status: Enabled
Extension: Installed

❯ Manage permissions
  Reconnect extension
  Enabled by default: No


**Native messaging host test output:**

$ echo '{"type":"ping"}' | /Users/user/.claude/chrome/chrome-native-host
[Claude Chrome Native Host] Initializing...
[Claude Chrome Native Host] Creating socket listener: /var/folders/.../claude-mcp-browser-bridge-user
[Claude Chrome Native Host] Socket server listening for connections
[Claude Chrome Native Host] Socket permissions set to 0600
[Claude Chrome Native Host] Invalid message length: 2037654139

Steps to Reproduce

1. Install Claude Chrome extension in Brave Browser from Chrome Web Store
2. Verify extension works (open side panel, it can see webpages)
3. Copy native messaging host manifest to Brave's directory:

``bash
mkdir -p ~/Library/Application\ Support/BraveSoftware/Brave-Browser/NativeMessagingHosts
cp ~/Library/Application\ Support/Google/Chrome/NativeMessagingHosts/com.anthropic.claude_code_browser_extension.json \
~/Library/Application\ Support/BraveSoftware/Brave-Browser/NativeMessagingHosts/
``

1. Start Claude Code with Chrome flag:

``bash
claude --chrome
``

1. Run /chrome command
2. Observe: "Extension: Not detected"

Comparison test with Chrome:

1. Install same extension in Google Chrome
2. Run claude --chrome
3. Run /chrome
4. Observe: "Extension: Installed" (works correctly)

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.0.73

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

Environment

• Claude Code version: v2.0.73
• Claude Chrome extension version: 1.0.36
• macOS version: Darwin 25.1.0
• Brave Browser version: Latest (installed via Homebrew)
• Google Chrome version: Latest

Native Messaging Host Configuration

Manifest location (Chrome - works):

~/Library/Application Support/Google/Chrome/NativeMessagingHosts/com.anthropic.claude_code_browser_extension.json

Manifest location (Brave - manually created, doesn't work):

~/Library/Application Support/BraveSoftware/Brave-Browser/NativeMessagingHosts/com.anthropic.claude_code_browser_extension.json

Manifest contents:

{
  "name": "com.anthropic.claude_code_browser_extension",
  "description": "Claude Code Browser Extension Native Host",
  "path": "/Users/user/.claude/chrome/chrome-native-host",
  "type": "stdio",
  "allowed_origins": [
    "chrome-extension://fcoeoabgfenejglbffodgkkbkcdhcgfn/"
  ]
}

Extension Details in Brave

• ID: fcoeoabgfenejglbffodgkkbkcdhcgfn (same as Chrome)
• Permissions: All required permissions granted including "Communicate with cooperating native applications"
• Site access: On all sites
• Status: Enabled and functional for standalone use

Observations

1. The extension ID is identical in both browsers
2. The native messaging host binary exists and is executable
3. The extension's standalone functionality works perfectly in Brave
4. Only the Claude Code ↔ extension connection fails in Brave
5. Brave may handle native messaging differently despite being Chromium-based

Suggested Fix

Consider either:

1. Adding explicit Brave Browser support with automatic native messaging host registration
2. Documenting that only Google Chrome is supported (if intentional)
3. Investigating why native messaging fails in Brave specifically

Workaround

Use Google Chrome instead of Brave Browser for Claude Code's Chrome integration.