{
  "mqtt_topics": {
    "base_topic": "smartintersection",
    "topics": {
      "detection": {
        "topic": "smartintersection/detection",
        "description": "Real-time object detection events",
        "qos": 1,
        "retain": false,
        "schema": {
          "timestamp": "ISO datetime",
          "camera_id": "string", 
          "objects": "array of detected objects",
          "frame_number": "integer",
          "processing_time_ms": "float"
        }
      },
      "violations": {
        "topic": "smartintersection/violations", 
        "description": "Traffic violations and safety alerts",
        "qos": 2,
        "retain": true,
        "schema": {
          "timestamp": "ISO datetime",
          "violation_type": "string",
          "severity": "low|medium|high|critical",
          "location": "ROI coordinates",
          "evidence": "object tracking data"
        }
      },
      "performance": {
        "topic": "smartintersection/performance",
        "description": "System performance metrics",
        "qos": 0,
        "retain": false,
        "schema": {
          "timestamp": "ISO datetime", 
          "fps": "float",
          "gpu_usage": "float (0-100)",
          "memory_usage": "float (MB)",
          "processing_time": "float (ms)"
        }
      },
      "traffic_flow": {
        "topic": "smartintersection/traffic/flow",
        "description": "Traffic flow analytics",
        "qos": 1,
        "retain": true,
        "schema": {
          "timestamp": "ISO datetime",
          "lane_id": "string",
          "vehicle_count": "integer", 
          "average_speed": "float (mph)",
          "congestion_level": "low|medium|high"
        }
      },
      "pedestrian_safety": {
        "topic": "smartintersection/safety/pedestrian",
        "description": "Pedestrian safety events",
        "qos": 2,
        "retain": true,
        "schema": {
          "timestamp": "ISO datetime",
          "event_type": "crosswalk_entry|unsafe_crossing|near_miss",
          "pedestrian_id": "string",
          "risk_level": "low|medium|high|critical",
          "location": "crosswalk coordinates"
        }
      },
      "roi_events": {
        "topic": "smartintersection/roi/events",
        "description": "Region of Interest events",
        "qos": 1,
        "retain": false,
        "schema": {
          "timestamp": "ISO datetime",
          "roi_id": "string",
          "roi_type": "crosswalk|lane|intersection",
          "event_type": "entry|exit|dwell|violation",
          "object_data": "tracking information"
        }
      },
      "camera_status": {
        "topic": "smartintersection/cameras/status",
        "description": "Camera health and status",
        "qos": 1,
        "retain": true,
        "schema": {
          "timestamp": "ISO datetime",
          "camera_id": "string",
          "position": "north|east|south|west",
          "status": "online|offline|error",
          "fps": "float",
          "resolution": "WxH"
        }
      },
      "system_health": {
        "topic": "smartintersection/system/health",
        "description": "Overall system health",
        "qos": 1,
        "retain": true,
        "schema": {
          "timestamp": "ISO datetime",
          "status": "healthy|degraded|critical",
          "active_cameras": "integer",
          "services_status": "object",
          "uptime_seconds": "integer"
        }
      }
    }
  },
  "publishing_config": {
    "broker_host": "localhost",
    "broker_port": 1883,
    "keepalive": 60,
    "client_id_prefix": "smart_intersection_",
    "auto_reconnect": true,
    "max_retries": 3,
    "retry_interval": 5
  }
}