{
    "service": "balloon-tracker",
    "status": "ok",
    "server_received_at": "2026-04-23T19:39:40+00:00",
    "node_id": "uplink-001",
    "role": "uplink",
    "battery_voltage": 3.927,
    "battery_percent": 69,
    "battery_valid": true,
    "wifi_rssi": -82,
    "ip": "192.168.178.67",
    "rx_count": 0,
    "uptime_ms": 18453517
}