Claude-in-Chrome: extension never connects ("Browser extension is not connected") despite install + login + restart

Summary

The claude-in-chrome MCP tools always return "Browser extension is not connected", even though the Claude browser extension is installed, Chrome is logged into the same claude.ai account as Claude Code, and Chrome has been fully restarted multiple times.

Steps taken (repeated multiple times, still failing)

• Confirmed the Claude browser extension is installed (from https://claude.ai/chrome)
• Confirmed logged into claude.ai in Chrome with the same account used by Claude Code
• Fully quit and restarted Chrome (Cmd+Q, not just closing the window)

Behavior observed

Every one of these calls returns the same not-connected error:

• list_connected_browsers → "Browser extension is not connected..."
• tabs_context_mcp (with createIfEmpty: true) → same error

The MCP server never sees any connected extension instance at all (not a browser-selection issue — zero browsers are reported).

Environment

• macOS 26.5.2 (build 25F84)
• Google Chrome 150.0.7871.182
• Claude Code 2.1.212

Expected

list_connected_browsers should report at least one connected Chrome extension instance so browser automation can proceed.