Claude-in-Chrome native host rejected by Gatekeeper (syspolicyd security_exception -67062/-67002) — macOS only, works fine on Windows

Claude Code CLI 2.1.283 (macOS, Homebrew Cask install at /opt/homebrew/Caskroom/claude-code@latest/2.1.283/), Claude in Chrome extension 1.0.94. tabs_context_mcp / any mcp__claude-in-chrome__* call consistently returns "Browser extension is not connected". Same account works fine on Windows.

Ruled out:

• Wrong claude.ai account — confirmed same account (auth status matches Chrome login)
• Extension disabled — confirmed enabled, correct ID (fcoeoabgfenejglbffodgkkbkcdhcgfn), service worker active, no console errors
• VPN/proxy interference — none active
• Fresh/isolated Chrome profile — same result
• Conflicting Claude Desktop native-messaging manifest (com.anthropic.claude_browser_extension.json) — disabled it + full Chrome restart, no change
• com.apple.quarantine on the claude binary — removed, no change
• Homebrew Cask vs. native installer (curl -fsSL https://claude.ai/install.sh) — installed native build side by side, repointed the wrapper script to it, no change

Root cause found via /usr/bin/log show, captured at the exact moment of a connection attempt:

syspolicyd[512:8526] [com.apple.securityd:security_exception] MacOS error: -67062
syspolicyd[512:8526] [com.apple.securityd:gk] temporarySigning type=1 matchFlags=0x0 path=/Users/zmojzes/.claude/chrome/chrome-native-host
syspolicyd[512:8526] [com.apple.securityd:security_exception] MacOS error: -67062
syspolicyd[512:8526] [com.apple.securityd:security_exception] MacOS error: -67002

~/.claude/chrome/chrome-native-host is an unsigned #!/bin/sh wrapper script (auto-generated, "do not edit manually") that execs the actual claude binary. Gatekeeper evaluates the wrapper script itself (not the binary it execs) and logs a security exception for it every time Chrome tries to launch it as a native messaging host — this looks like why it silently fails specifically on macOS, and would explain why the same setup works on Windows (no Gatekeeper equivalent there).

🤖 Generated with Claude Code