{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "title": "Product",
  "type": "object",
  "required": ["id", "qr_code", "name", "character_id"],
  "properties": {
    "id": { "type": "string" },
    "qr_code": { "type": "string" },
    "name": { "type": "string" },
    "brand": { "type": "string" },
    "description": { "type": "string" },
    "image_url": { "type": ["string", "null"] },
    "character_id": { "type": "string" },
    "knowledge_base_id": { "type": ["string", "null"] }
  }
}