{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "$id": "item.json#",
  "title": "STAC Item",
  "type": "object",
  "description": "This object represents the metadata for an item in a SpatioTemporal Asset Catalog.",
  "additionalProperties": true,
  "allOf": [
    {
      "$ref": "#/definitions/core"
    }
  ],
  "definitions": {
    "common_metadata": {
      "allOf": [
        {
          "$ref": "basics.json"
        },
        {
          "$ref": "datetimerange.json"
        },
        {
          "$ref": "instrument.json"
        },
        {
          "$ref": "licensing.json"
        },
        {
          "$ref": "metadata.json"
        },
        {
          "$ref": "provider.json"
        }
      ]
    },
    "core": {
      "allOf": [
        {
          "$ref": "https://geojson.org/schema/Feature.json"
        },
        {
          "type": "object",
          "required": [
            "stac_version",
            "id",
            "links",
            "assets",
            "bbox",
            "properties"
          ],
          "properties": {
            "stac_version": {
              "title": "STAC version",
              "type": "string",
              "const": "0.9.0-rc2"
            },
            "stac_extensions": {
              "title": "STAC extensions",
              "type": "array",
              "uniqueItems": true,
              "items": {
                "anyOf": [
                  {
                    "title": "Reference to a JSON Schema",
                    "type": "string",
                    "format": "uri"
                  },
                  {
                    "title": "Reference to a core extension",
                    "type": "string",
                    "enum": [
                      "checksum",
                      "commons",
                      "datacube",
                      "eo",
                      "label",
                      "pointcloud",
                      "projection",
                      "sar",
                      "sat",
                      "scientific",
                      "version",
                      "view"
                    ]
                  }
                ]
              }
            },
            "id": {
              "title": "Provider ID",
              "description": "Provider item ID",
              "type": "string"
            },
            "bbox": {
              "type": "array",
              "minItems": 4,
              "items": {
                "type": "number"
              }
            },
            "links": {
              "title": "Item links",
              "description": "Links to item relations",
              "type": "array",
              "items": {
                "$ref": "#/definitions/link"
              }
            },
            "assets": {
              "title": "Asset links",
              "description": "Links to assets",
              "type": "object",
              "additionalProperties": {
                "$ref": "#/definitions/asset"
              }
            },
            "properties": {
              "allOf": [
                {
                  "type": "object",
                  "required": [
                    "datetime"
                  ],
                  "properties": {
                    "datetime": {
                      "title": "Date and Time",
                      "description": "The searchable date/time of the assets, in UTC (Formatted in RFC 3339) ",
                      "type": "string",
                      "format": "date-time"
                    }
                  }
                },
                {
                  "$ref": "#/definitions/common_metadata"
                }
              ]
            },
            "collection": {
              "title": "Collection ID",
              "description": "The ID of the STAC Collection this Item references to.",
              "type": "string"
            }
          }
        }
      ]
    },
    "link": {
      "type": "object",
      "required": [
        "rel",
        "href"
      ],
      "properties": {
        "href": {
          "title": "Link reference",
          "type": "string"
        },
        "rel": {
          "title": "Link relation type",
          "type": "string"
        },
        "type": {
          "title": "Link type",
          "type": "string"
        },
        "title": {
          "title": "Link title",
          "type": "string"
        }
      }
    },
    "asset": {
      "type": "object",
      "required": [
        "href"
      ],
      "properties": {
        "href": {
          "title": "Asset reference",
          "type": "string"
        },
        "title": {
          "title": "Asset title",
          "type": "string"
        },
        "description": {
          "title": "Asset description",
          "type": "string"
        },
        "type": {
          "title": "Asset type",
          "type": "string"
        },
        "roles": {
          "title": "Asset roles",
          "type": "array",
          "items": {
            "type": "string"
          }
        }
      }
    }
  }
}