[BUG] Claude browser extension native messaging host not registered for Microsoft Edge

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 registers its native messaging hosts in the Windows registry only for Google Chrome, not for Microsoft Edge. The Claude browser extension can be installed in Edge (it's a Chromium-based browser that supports Chrome Web Store extensions), but the native messaging connection fails because Edge looks for host registrations under its own registry path.

Chrome registration (present):

• HKCU\SOFTWARE\Google\Chrome\NativeMessagingHosts\com.anthropic.claude_code_browser_extension
• HKCU\SOFTWARE\Google\Chrome\NativeMessagingHosts\com.anthropic.claude_browser_extension

Edge registration (missing):

• HKCU\SOFTWARE\Microsoft\Edge\NativeMessagingHosts\com.anthropic.claude_code_browser_extension
• HKCU\SOFTWARE\Microsoft\Edge\NativeMessagingHosts\com.anthropic.claude_browser_extension

The native messaging host manifest files (com.anthropic.claude_code_browser_extension.json and com.anthropic.claude_browser_extension.json) are browser-agnostic and already include the correct extension ID. Only the registry entries are missing for Edge.

What Should Happen?

During installation or setup, Claude Code should detect which Chromium-based browsers are present (Chrome, Edge, Brave, etc.) and register the native messaging hosts for each one. At minimum, Chrome and Edge should be supported since Edge is the default browser on Windows and has a large user base.

The extension itself should also be aware that it may be running in Edge rather than Chrome, and any browser-specific behavior should account for this.

Error Messages/Logs

# No error is shown to the user. The extension simply reports "Browser extension is not connected" 
# when Claude Code tries to use chrome-in-browser tools.
# The native messaging host is never launched because Edge cannot find the registry entry.

Steps to Reproduce

1. Install Claude Code on Windows
2. Install the Claude browser extension in Microsoft Edge (from Chrome Web Store)
3. Ensure you are logged into claude.ai in Edge
4. In Claude Code, attempt to use any claude-in-chrome MCP tool (e.g., tabs_context_mcp)
5. Observe "Browser extension is not connected" error
6. Verify the registry: reg query "HKCU\SOFTWARE\Microsoft\Edge\NativeMessagingHosts" /s returns nothing, while reg query "HKCU\SOFTWARE\Google\Chrome\NativeMessagingHosts" /s shows the registrations

Workaround: Manually adding the Edge registry entries resolves the discovery issue:

New-Item -Path 'HKCU:\SOFTWARE\Microsoft\Edge\NativeMessagingHosts\com.anthropic.claude_code_browser_extension' -Force | Set-ItemProperty -Name '(Default)' -Value '<path-to>\com.anthropic.claude_code_browser_extension.json'
New-Item -Path 'HKCU:\SOFTWARE\Microsoft\Edge\NativeMessagingHosts\com.anthropic.claude_browser_extension' -Force | Set-ItemProperty -Name '(Default)' -Value '<path-to>\com.anthropic.claude_browser_extension.json'

Claude Model

Not sure / Multiple models

Is this a regression?

I don't know

Claude Code Version

2.1.37 (Claude Code)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Windows Terminal

Additional Information

• The native messaging host manifests at %APPDATA%\Claude Code\ChromeNativeHost\ and %APPDATA%\Claude\ChromeNativeHost\ are browser-agnostic and work with Edge as-is
• Other Chromium browsers (Brave, Vivaldi, Opera, etc.) also use their own registry paths for native messaging hosts and would have the same issue
• Related issue: #24366 (native host crash with Unicode usernames)