{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "object",
  "additionalProperties": false,
  "minProperties": 1,
  "properties": {
    "product_id": { "type": "integer", "minimum": 1 },
    "sku": { "type": "string", "minLength": 1 }
  }
}