{
  "root": "yukart",
  "topics": {
    "yukart/can/raw": {
      "payload": "binary",
      "retained": false,
      "rate": "1000-3000/s",
      "publisher": "can-bridge",
      "description": "Timestamped raw frames. Binary, not the JSON envelope."
    },
    "yukart/vehicle/<signal>": {
      "payload": "envelope",
      "retained": true,
      "rate": "1-50/s",
      "publisher": "decoder (source z27ag), obd-poller (source obd2)",
      "description": "One topic per signal, named exactly as in signals.json."
    },
    "yukart/gnss/fix": {
      "payload": "envelope",
      "retained": true,
      "rate": "1-10/s",
      "publisher": "gnss",
      "description": "value is an object: lat, lon, alt_m, speed_kph, heading_deg, fix, satellites."
    },
    "yukart/gnss/<signal>": {
      "payload": "envelope",
      "retained": true,
      "rate": "1-10/s",
      "publisher": "gnss",
      "description": "The receiver's fix as single values, one topic per signal, named exactly as in signals.json (source=gnss). For displays; yukart/gnss/fix stays the composite for navigation."
    },
    "yukart/host/<signal>": {
      "payload": "envelope",
      "retained": true,
      "rate": "1/s",
      "publisher": "orin-status",
      "description": "The Orin itself: temperatures, load, memory, network links, UPS battery. One topic per signal, named exactly as in signals.json (source=host)."
    },
    "yukart/system/<service>": {
      "payload": "json",
      "retained": true,
      "rate": "on change",
      "publisher": "every service",
      "description": "state: starting|ready|degraded|stopping, plus service-specific detail."
    },
    "yukart/nav/guidance": {
      "payload": "json",
      "retained": true,
      "rate": "on change",
      "publisher": "svc-nav",
      "description": "Next manoeuvre, distance, street name."
    },
    "yukart/nav/route": {
      "payload": "json",
      "retained": true,
      "rate": "on change",
      "publisher": "svc-nav",
      "description": "Active route geometry."
    },
    "yukart/session/mark": {
      "payload": "json",
      "retained": false,
      "rate": "human",
      "publisher": "svc-gw",
      "description": "Operator event stamped into the recording. Carries both clocks like the envelope."
    }
  }
}