Add-on, calibrated units: normalized_index and pct_to_action so readings compare across st

[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0x2d16a243ba9facc6ac85519d5efad2149dc4c6c3",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "5000",
    "maxTimeoutSeconds": 300
  },
  {
    "scheme": "exact",
    "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
    "payTo": "8qEn3Y3GPXdQ28LHshPa4UYeD8V38Lq9b4jCRirQAY3n",
    "asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
    "amount": "5000",
    "maxTimeoutSeconds": 300
  }
]

{
  "bazaar": {
    "discoverable": true,
    "info": {
      "input": {
        "example": {
          "entity": "07010000",
          "format": "thin",
          "signal_id": "hydrology.river-level"
        },
        "exampleRequest": "/gauge/calibrated?signal_id=hydrology.river-level&entity=07010000&format=thin",
        "method": "GET",
        "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)"
        },
        "type": "http"
      },
      "output": {
        "example": {
          "calibrated": {
            "band": "below_action",
            "current_value": 6.48,
            "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)",
            "metric": "gauge_height_ft",
            "normalized_index": -0.769,
            "pct_to_action": 0.231,
            "scale": "flood_stage",
            "unit": "ft"
          },
          "dim": "calibrated",
          "entity": "07010000",
          "entity_name": "Mississippi River at St. Louis, MO",
          "grade": "screening-level, not decision-grade",
          "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.",
          "observed_at": "2026-08-26T09:30:00.000Z",
          "provenance": {
            "age_hours_now": 5.5,
            "freshness": "fresh",
            "freshness_basis": "cadence=daily; fresh<=24h; recent<=192h; dead_source>1440h; age_basis=request-time(now minus observed_at)"
          },
          "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."
          },
          "scope": {
            "full": "https://api.truthbear.co/scope/v1",
            "intelligence_not_command": true,
            "monitoring_not_forecast": true,
            "verifiability": "via-endpoint"
          },
          "signal_id": "hydrology.river-level",
          "source_ref": "https://waterdata.usgs.gov/monitoring-location/07010000/"
        },
        "type": "json"
      }
    },
    "outputSchemaRef": "/manifest",
    "priceUsd": "$0.005",
    "priceUsdNumber": 0.005,
    "routeTemplate": "/gauge/calibrated",
    "schema": {
      "$schema": "https://json-schema.org/draft/2020-12/schema",
      "properties": {
        "input": {
          "properties": {
            "method": {
              "enum": [
                "GET"
              ],
              "type": "string"
            },
            "queryParams": {
              "additionalProperties": false,
              "properties": {
                "entity": {
                  "description": "required - monitored object id, paired with signal_id; free list at GET /gauge/catalog?signal_id=<signal_id> -> signals[0].entities[]",
                  "examples": [
                    "07010000"
                  ],
                  "type": "string"
                },
                "signal_id": {
                  "description": "required - signal id (genus.species); free list at GET /gauge/catalog (paged; ?all=1 for every line)",
                  "examples": [
                    "hydrology.river-level"
                  ],
                  "type": "string"
                }
              },
              "required": [
                "signal_id",
                "entity"
              ],
              "type": "object"
            },
            "type": {
              "const": "http"
            }
          },
          "required": [
            "type",
            "method",
            "queryParams"
          ],
          "type": "object"
        },
        "output": {
          "properties": {
            "example": {},
            "type": {
              "const": "json"
            }
          },
          "required": [
            "type"
          ],
          "type": "object"
        }
      }
    }
  }
}

curl "https://api.truthbear.co/gauge/calibrated"
# -> 402 Payment Required, accepts[] lists how to pay
# retry with a PAYMENT-SIGNATURE (or PAYMENT header) once paid

const res = await fetch("https://api.truthbear.co/gauge/calibrated");
if (res.status === 402) {
  const { accepts } = await res.json();
  // pay one of accepts[] via an x402 client, then retry with the payment header
}

import httpx
res = httpx.get("https://api.truthbear.co/gauge/calibrated")
if res.status_code == 402:
    accepts = res.json()["accepts"]
    # pay one of accepts[] via an x402 client, then retry with the payment header