Install this Claude Code hook.
Name: Notify on Long Run
Save to: ~/.claude/hooks/notify-on-long-run.sh
Make executable: yes

---
#!/usr/bin/env bash
# Hook type: Stop / PostToolUse
# Trigger: Bash tool calls that complete after a long duration
#
# Place this in your hooks config:
#   hooks:
#     PostToolUse:
#       - matcher: "Bash"
#         hooks:
#           - type: command
#             command: /path/to/notify-on-long-run.sh

set -euo pipefail

# Read JSON from stdin
INPUT=$(cat)
TOOL=$(echo "$INPUT" | python3 -c "import sys,json; d=json.load(sys.stdin); print(d.get('tool_name',''))" 2>/dev/null || true)

if [ "$TOOL" != "Bash" ]; then
  exit 0
fi

DURATION=$(echo "$INPUT" | python3 -c "
import sys, json
d = json.load(sys.stdin)
print(d.get('duration_ms', 0))
" 2>/dev/null || echo "0")

THRESHOLD=30000  # 30 seconds in ms

if [ "$DURATION" -lt "$THRESHOLD" ]; then
  exit 0
fi

CMD=$(echo "$INPUT" | python3 -c "
import sys, json
d = json.load(sys.stdin)
cmd = d.get('tool_input', {}).get('command', 'unknown command')
print(cmd[:80])
" 2>/dev/null || echo "command")

SECONDS_TAKEN=$(( DURATION / 1000 ))
MESSAGE="Finished in ${SECONDS_TAKEN}s: $CMD"

# macOS
if command -v osascript &>/dev/null; then
  osascript -e "display notification \"$MESSAGE\" with title \"Claude Code\""
# Linux (notify-send)
elif command -v notify-send &>/dev/null; then
  notify-send "Claude Code" "$MESSAGE"
fi