[Bug] Claude Desktop native messaging host intercepts Chrome extension connection, blocking Claude Code integration

[darkneo29]

Description

When both Claude Desktop app and Claude Code are installed on macOS, the Chrome extension fails to connect to Claude Code with the error: "Browser extension is not connected."

Root Cause

Both Claude Desktop and Claude Code register native messaging host configurations in ~/Library/Application Support/Google/Chrome/NativeMessagingHosts/ with the same allowed_origins extension IDs. The Claude Desktop config (com.anthropic.claude_browser_extension.json) takes precedence, causing the Chrome extension to connect to Claude Desktop's native host instead of Claude Code's.

Environment

• OS: macOS (Darwin 25.2.0)
• Claude Code Version: 2.1.17
• Chrome Extension ID: fcoeoabgfenejglbffodgkkbkcdhcgfn

Steps to Reproduce

1. Have both Claude Desktop app and Claude Code installed
2. Install the Claude Chrome extension
3. Run claude --chrome
4. Try to use any Chrome integration tool
5. Error: "Browser extension is not connected"

Workaround

Replace the Claude Desktop native host config to point to Claude Code:

# Backup the Claude Desktop config
mv ~/Library/Application\ Support/Google/Chrome/NativeMessagingHosts/com.anthropic.claude_browser_extension.json \
   ~/Library/Application\ Support/Google/Chrome/NativeMessagingHosts/com.anthropic.claude_browser_extension.json.backup

# Create new config pointing to Claude Code
cat > ~/Library/Application\ Support/Google/Chrome/NativeMessagingHosts/com.anthropic.claude_browser_extension.json << 'EOF'
{
  "name": "com.anthropic.claude_browser_extension",
  "description": "Claude Browser Extension Native Host",
  "path": "/Users/USERNAME/.claude/chrome/chrome-native-host",
  "type": "stdio",
  "allowed_origins": [
    "chrome-extension://dihbgbndebgnbjfmelmegjepbnkhlgni/",
    "chrome-extension://fcoeoabgfenejglbffodgkkbkcdhcgfn/",
    "chrome-extension://dngcpimnedloihjnnfngkgjoidhnaolf/"
  ]
}
EOF

# Restart Chrome

Expected Behavior

Claude Code and Claude Desktop should be able to coexist without conflicting native messaging host registrations. Possible solutions:

• Use different native messaging host names for each application
• Add a mechanism to switch between Claude Desktop and Claude Code connections
• Detect the conflict and provide a clear error message with resolution steps

Additional Context

The /chrome reconnect option opens Chrome briefly then closes without properly installing the native messaging host when this conflict exists.

[github-actions]

Found 2 possible duplicate issues:

1. [Bug] Claude in Chrome fails when Claude Desktop native messaging host config exists (macOS) #20316
2. Claude in Chrome browser extension not connecting to Claude Code CLI #20298

This issue will be automatically closed as a duplicate in 3 days.

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🤖 Generated with Claude Code

[tonydehnke]

Additional findings from debugging session

Orphan native host process persists after reboot

Even when Claude Desktop app is not running, Chrome starts the Claude Desktop native host process on launch because the extension auto-restores and requests native messaging.

Steps to reproduce:

1. Reboot macOS
2. Do NOT open Claude Desktop app
3. Open Chrome (extension auto-restores)
4. Check processes: ps aux | grep chrome-native-host
5. Observe: /Applications/Claude.app/Contents/Helpers/chrome-native-host is running despite Desktop app never being opened

Why killing the orphan doesn't help

1. Killed orphan process (PID of Claude Desktop's native host)
2. No native host running afterward
3. Chrome extension still shows "not connected" in Claude Code
4. Extension needs to be triggered to start a NEW native host
5. When triggered, Chrome picks Desktop's config again (alphabetically first)

Root cause detail

Chrome has two native messaging host configs claiming the same extension ID:

• com.anthropic.claude_browser_extension.json → points to /Applications/Claude.app/...
• com.anthropic.claude_code_browser_extension.json → points to ~/.claude/chrome/...

Chrome appears to pick based on alphabetical order of config filename:

• "browser" < "code" alphabetically
• So Desktop's config wins every time

Environment

• macOS Darwin 25.2.0
• Claude Code 2.1.19
• Chrome 144.x
• Claude Desktop app installed but NOT running

Suggested fix

The native messaging host configs should use different host names rather than both trying to claim the same extension ID. This would allow:

1. Extension to specify which host to connect to
2. Or a broker/router process that can forward to the correct host based on which client is active

[jbkjr]

Confirming this issue on macOS Darwin 25.2.0 with Claude Code 2.1.19 and Claude Desktop installed.

/chrome shows "Status: Enabled, Extension: Installed" but tabs_context_mcp always returns "Browser extension is not connected."

Debugging confirmed the native host running is /Applications/Claude.app/Contents/Helpers/chrome-native-host - the Desktop one, not Claude Code's. The socket at /tmp/claude-mcp-browser-bridge-*/ is created by Desktop's host but Claude Code's MCP process never connects to it.

This breaks --chrome functionality for anyone with both apps installed. A proper fix (broker process or separate extension IDs) would be appreciated - the current workaround of disabling Desktop's native host config isn't sustainable.

[harrywang]

same issue, I fixed by doing the following - very frustrated till get this solved:

Summary: Claude in Chrome Connection Fix

Problem: The Chrome extension was connecting to Claude Desktop instead of Claude Code CLI because both
apps registered native messaging hosts for the same extension.

Diagnosis:

1. Searched GitHub issues and found this is a known conflict
2. Checked ~/Library/Application Support/Google/Chrome/NativeMessagingHosts/
3. Found two config files pointing to the same extension ID:
   - com.anthropic.claude_browser_extension.json → Claude Desktop
   - com.anthropic.claude_code_browser_extension.json → Claude Code

Fix:
mv ~/Library/Application
Support/Google/Chrome/NativeMessagingHosts/com.anthropic.claude_browser_extension.json
~/Library/Application
Support/Google/Chrome/NativeMessagingHosts/com.anthropic.claude_browser_extension.json.bak

Then restarted Chrome.

To restore (if you need Claude Desktop to use the extension again):
mv ~/Library/Application
Support/Google/Chrome/NativeMessagingHosts/com.anthropic.claude_browser_extension.json.bak
~/Library/Application
Support/Google/Chrome/NativeMessagingHosts/com.anthropic.claude_browser_extension.json

[chadneal]

Confirming this issue on:

• macOS Darwin 25.2.0
• Claude Code 2.1.19
• Claude Desktop 1.1.886
• Chrome Extension 1.0.40

Additional diagnostic info:

The native host logs show Claude Desktop's host creating the socket and accepting MCP connections:

[INFO] Socket created at: /tmp/claude-mcp-browser-bridge-chad/<pid>.sock
[INFO] Accepted new MCP connection (client 1)
[INFO] MCP client 1 disconnected

Claude Code's MCP server never connects to this socket because it expects its own native host.

Workaround confirmed working:

mv ~/Library/Application\ Support/Google/Chrome/NativeMessagingHosts/com.anthropic.claude_browser_extension.json \
   ~/Library/Application\ Support/Google/Chrome/NativeMessagingHosts/com.anthropic.claude_browser_extension.json.disabled

Then restart Chrome.

This leaves only Claude Code's config active (com.anthropic.claude_code_browser_extension.json).