{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "$id": "https://github.com/api-evangelist/schema-free/blob/main/json-schema/schema-free-document-schema.json",
  "title": "Schema-Free Document",
  "description": "Represents a document in a schema-free (schemaless) database. Only minimal metadata fields are required; all other content is flexible and application-defined.",
  "type": "object",
  "properties": {
    "_id": {
      "type": "string",
      "description": "Unique identifier for the document (auto-assigned or application-provided)"
    },
    "_collection": {
      "type": "string",
      "description": "Collection or table name this document belongs to"
    },
    "_version": {
      "type": "integer",
      "description": "Optimistic concurrency version number for the document",
      "minimum": 1
    },
    "_created": {
      "type": "string",
      "format": "date-time",
      "description": "Timestamp when the document was first created"
    },
    "_modified": {
      "type": "string",
      "format": "date-time",
      "description": "Timestamp when the document was last modified"
    },
    "_type": {
      "type": "string",
      "description": "Application-level document type discriminator (e.g., 'user', 'order', 'product')"
    }
  },
  "additionalProperties": true,
  "description_notes": "The additionalProperties: true setting reflects the schemaless nature of these databases — any additional fields are valid. Application-level validation handles field constraints.",
  "examples": [
    {
      "_id": "64f8c9d12a3e4b5c6d7e8f90",
      "_collection": "products",
      "_version": 3,
      "_created": "2026-01-15T09:00:00Z",
      "_modified": "2026-05-01T14:30:00Z",
      "_type": "physical-product",
      "name": "Zebra ZD421 Label Printer",
      "sku": "ZD42143-D0E000EZ",
      "price": 249.99,
      "tags": ["barcode", "thermal", "desktop"],
      "specs": {
        "resolution": "203 dpi",
        "maxPrintWidth": 4.09,
        "interfaces": ["USB", "Ethernet", "Bluetooth"]
      }
    }
  ]
}