{
  "type": "record",
  "name": "Telemetry",
  "namespace": "com.hongbomiao.telemetry",
  "fields": [
    { "name": "publisher_id", "type": "string" },
    { "name": "timestamp_ns", "type": "long" },
    { "name": "temperature_c", "type": "double" },
    { "name": "humidity_pct", "type": "double" }
  ]
}
