Claude-in-Chrome extension not connecting to Claude Code (accounts match, handshake never completes)

Description

The Claude-in-Chrome browser extension does not connect to Claude Code CLI despite accounts matching on both sides.

Environment

• Platform: macOS (Darwin 25.4.0)
• Claude Code model: claude-sonnet-4-6
• Browser: Google Chrome
• Extension status: Installed, enabled, beta acceptance completed

Steps to reproduce

1. Install the Claude-in-Chrome extension from https://claude.ai/chrome
2. Accept the beta terms when prompted
3. Log into claude.ai in Chrome with the same Anthropic account used by Claude Code
4. Open Claude Code CLI
5. Run /mcp — MCP server reconnects successfully on the Claude Code side
6. Attempt any mcp__claude-in-chrome__* tool call

Expected behavior

Browser extension connects and browser automation tools become available.

Actual behavior

Every call returns: "Browser extension is not connected. Please ensure the Claude browser extension is installed and running (https://claude.ai/chrome), and that you are logged into claude.ai with the same account as Claude Code."

Additional context

• Chrome was fully restarted (Cmd+Q) multiple times
• Extension is enabled in chrome://extensions
• Extension IS working as a claude.ai sidebar (visible in browser) — it appears to connect to the claude.ai web interface but not to Claude Code CLI
• Accounts on claude.ai and Claude Code are confirmed to match
• /mcp reconnect on the Claude Code side completes successfully, but the browser handshake never follows

Contact

chad.lester@outlook.com