{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "commodities",
  "type": "object",
  "required": ["published_at", "groups"],
  "additionalProperties": false,
  "properties": {
    "published_at": {"type": "string"},
    "groups": {
      "type": "array",
      "items": {
        "type": "object",
        "required": ["group", "rows"],
        "additionalProperties": false,
        "properties": {
          "group": {"type": "string"},
          "rows": {
            "type": "array",
            "items": {
              "type": "object",
              "required": ["code", "label", "unit", "value", "as_of",
                           "yoy_pct", "chg_30d_pct", "spark"],
              "additionalProperties": false,
              "properties": {
                "code": {"type": "string"},
                "label": {"type": "string"},
                "unit": {"type": "string"},
                "value": {"type": ["number", "null"]},
                "as_of": {"type": ["string", "null"]},
                "yoy_pct": {"type": ["number", "null"]},
                "chg_30d_pct": {"type": ["number", "null"]},
                "spark": {"type": "array", "items": {"type": "number"}}
              }
            }
          }
        }
      }
    }
  }
}