{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://raw.githubusercontent.com/api-evangelist/energy-utilities/refs/heads/main/json-schema/energy-utilities-meter-reading-schema.json",
  "title": "MeterReading",
  "description": "A single point-in-time or interval-based reading captured by a utility meter. Generalizes the Green Button ESPI MeterReading / IntervalReading model so the same shape can carry electricity, natural gas, and water measurements from a retail utility, a third-party integrator (UtilityAPI, Bayou, Arcadia), or an AMI back-office.",
  "type": "object",
  "required": [
    "id",
    "usagePointId",
    "readingType",
    "intervalStart",
    "intervalLength",
    "value",
    "unit"
  ],
  "properties": {
    "id": {
      "type": "string",
      "description": "Provider-scoped identifier for this reading. Stable across re-pulls of the same meter interval."
    },
    "usagePointId": {
      "type": "string",
      "description": "Reference to the UsagePoint (meter / service delivery point) that produced this reading."
    },
    "meterId": {
      "type": "string",
      "description": "Optional reference to the physical meter device when a UsagePoint is served by more than one meter over time."
    },
    "readingType": {
      "type": "string",
      "description": "Semantic classification of what was measured. Aligned with the ESPI ReadingType commodity / measurement-kind taxonomy.",
      "enum": [
        "electricity.usage",
        "electricity.demand",
        "electricity.delivered",
        "electricity.received",
        "electricity.net",
        "electricity.reactive",
        "natural-gas.usage",
        "water.usage",
        "steam.usage",
        "thermal.usage"
      ]
    },
    "intervalStart": {
      "type": "string",
      "format": "date-time",
      "description": "UTC start of the measurement interval (ISO 8601). For instantaneous readings, intervalStart is the measurement timestamp."
    },
    "intervalLength": {
      "type": "integer",
      "minimum": 0,
      "description": "Duration of the interval in seconds. 0 indicates an instantaneous reading (no integration window). Common values: 900 (15 min), 3600 (1 hour), 86400 (1 day)."
    },
    "value": {
      "type": "number",
      "description": "Measured quantity in the units identified by unit. Negative values are allowed for net-metered flows where generation exceeds consumption."
    },
    "unit": {
      "type": "string",
      "description": "Unit of measure. SI / industry-standard abbreviations.",
      "enum": [
        "Wh",
        "kWh",
        "MWh",
        "W",
        "kW",
        "MW",
        "VARh",
        "kVARh",
        "VA",
        "kVA",
        "ccf",
        "therms",
        "MMBtu",
        "m3",
        "gallons",
        "liters"
      ]
    },
    "quality": {
      "type": "string",
      "description": "Data quality flag reflecting the meter or pipeline's confidence in the reading.",
      "enum": [
        "valid",
        "estimated",
        "missing",
        "questionable",
        "raw",
        "validated",
        "edited"
      ]
    },
    "source": {
      "type": "string",
      "description": "Origin of the reading. Helps consumers distinguish AMI smart-meter data from manual reads or third-party estimates.",
      "enum": [
        "ami",
        "amr",
        "manual",
        "estimated",
        "third-party",
        "green-button"
      ]
    },
    "powerOfTenMultiplier": {
      "type": "integer",
      "description": "Power-of-ten multiplier applied to value to recover the raw measurement, mirroring the ESPI ReadingType.powerOfTenMultiplier field. Optional; default 0 (no scaling)."
    },
    "tariffRider": {
      "type": "string",
      "description": "Optional tariff rider, time-of-use bucket, or rate code under which the reading was metered."
    },
    "providerId": {
      "type": "string",
      "description": "Identifier of the API or system that delivered the reading (e.g. utilityapi, bayou, arcadia, espi)."
    },
    "metadata": {
      "type": "object",
      "description": "Provider-specific extensions that do not map into the core meter reading model.",
      "additionalProperties": true
    }
  },
  "additionalProperties": false
}