Claude-in-Chrome: extension not connected despite working native host socket (Linux, custom Chrome profile)

Environment

• Claude Code: v2.1.68
• OS: Pop!_OS 24.04 (Linux 6.18.7, x86_64)
• Chrome: 145.0.7632.159
• Extension: Claude v1.0.56 (fcoeoabgfenejglbffodgkkbkcdhcgfn)
• Chrome profile: Custom --user-data-dir (~/.config/google-chrome-claude)

Problem

All mcp__claude-in-chrome__* tools return "Browser extension is not connected" despite the entire connection chain being verified as working:

1. Extension installed and enabled with nativeMessaging permission
2. Logged into claude.ai in Chrome
3. Native messaging host config present in ~/.config/google-chrome-claude/NativeMessagingHosts/com.anthropic.claude_code_browser_extension.json
4. Native host process running: /home/neuro/.local/share/claude/versions/2.1.68 --chrome-native-host (spawned by Chrome)
5. Unix socket created at /tmp/claude-mcp-browser-bridge-neuro/<pid>.sock
6. Socket is connectable (verified with Python socket.connect())
7. /mcp command reports "Reconnected to claude-in-chrome"

Yet every tool call (e.g., tabs_context_mcp, switch_browser) still returns the "not connected" error.

Steps to reproduce

1. Install Google Chrome on Linux
2. Create a custom Chrome profile: google-chrome --user-data-dir=~/.config/google-chrome-claude
3. Install the Claude extension from Chrome Web Store
4. Log into claude.ai
5. Start Claude Code CLI
6. Call any claude-in-chrome MCP tool → "Browser extension is not connected"

Additional context

• The native messaging host config was initially only present in ~/.config/google-chrome/NativeMessagingHosts/ (the default profile). Copying it to the custom profile's NativeMessagingHosts/ directory fixed the socket creation issue, but the MCP tools still can't connect.
• Previously also tried with Brave Browser (separate profile at default location) — same "not connected" result despite identical setup. Extension was installed, native messaging configured, logged into claude.ai. Removed Brave extension entirely before switching to clean Chrome install.
• The Claude sidebar in Chrome works fine for chat (Sonnet 4.6), suggesting the extension itself is functional.
• This may be a handshake issue between the Claude Code MCP layer and the extension's native messaging, or the extension may not be initiating the Claude Code connection despite having the native host available.

Expected behavior

tabs_context_mcp should return tab information and establish a working browser automation session.