Claude in Chrome: Native messaging host not installed for Chromium/Brave browsers (Linux)

Description

The Claude in Chrome extension (v1.0.35) fails to connect with Claude Code (v2.0.72) when using Chromium-based browsers other than Google Chrome on Linux.

Environment

• OS: Arch Linux (6.17.9-arch1-1)
• Claude Code: 2.0.72
• Chrome Extension: 1.0.35
• Affected Browsers: Chromium, Brave (likely all non-Google Chrome Chromium-based browsers)

Problem

The native messaging host configuration file is only installed in the Google Chrome directory:

~/.config/google-chrome/NativeMessagingHosts/com.anthropic.claude_code_browser_extension.json

Other Chromium-based browsers look in their own directories:

• Chromium: ~/.config/chromium/NativeMessagingHosts/
• Brave: ~/.config/BraveSoftware/Brave-Browser/NativeMessagingHosts/
• Vivaldi: ~/.config/vivaldi/NativeMessagingHosts/
• Edge: ~/.config/microsoft-edge-dev/NativeMessagingHosts/

Symptoms

• Extension installed and enabled
• Claude panel opens in browser
• MCP server shows "Successfully connected" in debug logs
• But tabs_context_mcp returns "Browser extension is not connected"

Workaround

Copy the native messaging host config to the appropriate browser directory:

# For Chromium
cp ~/.config/google-chrome/NativeMessagingHosts/com.anthropic.claude_code_browser_extension.json \
   ~/.config/chromium/NativeMessagingHosts/

# For Brave
cp ~/.config/google-chrome/NativeMessagingHosts/com.anthropic.claude_code_browser_extension.json \
   ~/.config/BraveSoftware/Brave-Browser/NativeMessagingHosts/

Then restart the browser.

Suggested Fix

The installer should either:

1. Detect installed Chromium-based browsers and configure native messaging hosts for all of them
2. Or install to a system-wide location like /etc/chromium/native-messaging-hosts/ (though this requires root)
3. Or document that only Google Chrome is officially supported

Notes

• The extension ID (fcoeoabgfenejglbffodgkkbkcdhcgfn) is the same across browsers
• The native host executable at ~/.claude/chrome/chrome-native-host works correctly once the config is in place