Problem: macOS hostname command returns 'Mikes-MacBook-Air.local' but coord messages are addressed to 'Mikes-MacBook-Air/claude-main'. Hook script was querying for wrong session ID, so messages never displayed. Fix: Strip .local suffix using bash parameter expansion before building session ID. Result: Coord messages now display correctly on macOS machines. Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>