cc-os/plugins/os-backlog/hooks/hooks.json

{
  "hooks": {
    "SessionStart": [
      {
        "matcher": "startup|resume|compact",
        "hooks": [
          {
            "type": "command",
            "command": "python3 ${CLAUDE_PLUGIN_ROOT}/hooks/session_start.py",
            "timeout": 5
          }
        ]
      }
    ]
  }
}