{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "$id": "https://raw.githubusercontent.com/api-evangelist/carbon-intensity/main/json-schema/intensity-period.json",
  "title": "Intensity Period",
  "description": "Carbon intensity data for a single 30-minute period for Great Britain national grid",
  "type": "object",
  "properties": {
    "from": {
      "type": "string",
      "format": "date-time",
      "description": "Start of the half-hour period in ISO 8601 format",
      "example": "2018-01-20T12:00Z"
    },
    "to": {
      "type": "string",
      "format": "date-time",
      "description": "End of the half-hour period in ISO 8601 format",
      "example": "2018-01-20T12:30Z"
    },
    "intensity": {
      "type": "object",
      "description": "Carbon intensity measurements",
      "properties": {
        "forecast": {
          "type": "integer",
          "description": "Forecasted carbon intensity in gCO2/kWh",
          "minimum": 0,
          "example": 266
        },
        "actual": {
          "type": ["integer", "null"],
          "description": "Actual carbon intensity in gCO2/kWh (null for future periods)",
          "minimum": 0,
          "example": 263
        },
        "index": {
          "type": "string",
          "description": "Qualitative carbon intensity index",
          "enum": ["very low", "low", "moderate", "high", "very high"],
          "example": "moderate"
        }
      },
      "required": ["forecast", "index"]
    }
  },
  "required": ["from", "to", "intensity"]
}