gauge calibrated derived

{
  "input": {
    "type": "http",
    "method": "GET",
    "example": {
      "entity": "07010000",
      "format": "thin",
      "signal_id": "hydrology.river-level"
    },
    "queryParams": {
      "entity": "required - monitored object id, paired with signal_id; free list at GET /gauge/catalog?signal_id=<signal_id> -> signals[",
      "signal_id": "required - signal id (genus.species); free list at GET /gauge/catalog (paged; ?all=1 for every line)"
    },
    "exampleRequest": "/gauge/calibrated?signal_id=hydrology.river-level&entity=07010000&format=thin"
  },
  "output": {
    "type": "json",
    "example": {
      "dim": "calibrated",
      "grade": "screening-level, not decision-grade",
      "scope": {
        "full": "https://api.truthbear.co/scope/v1",
        "verifiability": "via-endpoint",
        "monitoring_not_forecast": true,
        "intelligence_not_command": true
      },
      "entity": "07010000",
      "nature": "This API supplies data organisation and trend description only. It is not a recommendation to act; the decision is yours. Purely descriptive - no judgement, no prediction. Official source plus record_hash; verify with the free /gauge/verify.",
      "signal_id": "hydrology.river-level",
      "calibrated": {
        "band": "below_action",
        "unit": "ft",
        "scale": "flood_stage",
        "metric": "gauge_height_ft",
        "index_basis": "normalized_index: piecewise linear (action=0/minor=1/moderate=2/major=3); below the first band = (value - first threshold) / first threshold, clamped to [-1,0); above the top band it is unbounded. pct_to_action = value / first alert threshold (bounded, 1 = at the first alert)",
        "current_value": 6.48,
        "pct_to_action": 0.231,
        "normalized_index": -0.769
      },
      "provenance": {
        "freshness": "fresh",
        "age_hours_now": 5.5,
        "freshness_basis": "cadence=daily; fresh<=24h; recent<=192h; dead_source>1440h; age_basis=request-time(now minus observed_at)"
      },
      "source_ref": "https://waterdata.usgs.gov/monitoring-location/07010000/",
      "entity_name": "Mississippi River at St. Louis, MO",
      "observed_at": "2026-08-26T09:30:00.000Z",
      "record_hash": "sha256:a3986d8689a1d9f6e8b4b92c2318d5af64291cdedbdbd3d706e0049e16fcb42e",
      "record_hash_verifiable": {
        "mode": "via-endpoint",
        "note": "This response is a projected delivery (some core fields are omitted to control size). Cross-check record_hash with the free /gauge/verify, or buy /gauge to get the complete core for offline recomputation."
      }
    }
  }
}