schema.json

{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "$id": "https://stacchain.github.io/merkle-tree/v1.0.0/schema.json#",
  "title": "Merkle Tree Root Extension",
  "description": "An extension to ensure metadata integrity for STAC Items, Collections, and Catalogs by encoding them in a Merkle tree via hashing.",
  "oneOf": [
    {
      "$comment": "This is the schema for STAC Items.",
      "allOf": [
        {
          "$ref": "#/definitions/stac_extensions"
        },
        {
          "type": "object",
          "required": ["type", "properties"],
          "properties": {
            "type": {
              "const": "Feature"
            },
            "properties": {
              "type": "object",
              "required": ["merkle:object_hash"],
              "properties": {
                "merkle:object_hash": {
                  "type": "string",
                  "description": "A cryptographic hash of the Item's metadata."
                }
              },
              "additionalProperties": true
            }
          }
        }
      ]
    },
    {
      "$comment": "This is the schema for STAC Collections.",
      "allOf": [
        {
          "$ref": "#/definitions/stac_extensions"
        },
        {
          "type": "object",
          "required": [
            "type",
            "id",
            "merkle:object_hash",
            "merkle:hash_method",
            "merkle:root"
          ],
          "properties": {
            "type": {
              "const": "Collection"
            },
            "merkle:object_hash": {
              "type": "string",
              "description": "A cryptographic hash of the Collection's metadata."
            },
            "merkle:hash_method": {
              "$ref": "#/definitions/hash_method",
              "description": "An object describing the method used to compute the hashes."
            },
            "merkle:root": {
              "type": "string",
              "description": "The Merkle root hash representing the Collection."
            }
          },
          "additionalProperties": true
        }
      ]
    },
    {
      "$comment": "This is the schema for STAC Catalogs.",
      "allOf": [
        {
          "$ref": "#/definitions/stac_extensions"
        },
        {
          "type": "object",
          "required": [
            "type",
            "id",
            "merkle:object_hash",
            "merkle:hash_method",
            "merkle:root"
          ],
          "properties": {
            "type": {
              "const": "Catalog"
            },
            "merkle:object_hash": {
              "type": "string",
              "description": "A cryptographic hash of the Catalog's metadata."
            },
            "merkle:hash_method": {
              "$ref": "#/definitions/hash_method",
              "description": "An object describing the method used to compute the hashes."
            },
            "merkle:root": {
              "type": "string",
              "description": "The Merkle root hash representing the Catalog."
            }
          },
          "additionalProperties": true
        }
      ]
    }
  ],
  "definitions": {
    "stac_extensions": {
      "type": "object",
      "required": ["stac_extensions"],
      "properties": {
        "stac_extensions": {
          "type": "array",
          "contains": {
            "const": "https://stacchain.github.io/merkle-tree/v1.0.0/schema.json"
          }
        }
      }
    },
    "hash_method": {
      "type": "object",
      "required": ["function", "fields"],
      "properties": {
        "function": {
          "type": "string",
          "description": "The cryptographic hash function used (e.g., 'sha256', 'sha3-256')."
        },
        "fields": {
          "oneOf": [
            {
              "type": "array",
              "items": {
                "type": "string"
              }
            },
            {
              "type": "string",
              "enum": ["*", "all"]
            }
          ],
          "description": "An array of fields included in the hash computation. Use '*' or 'all' to indicate all fields."
        },
        "ordering": {
          "type": "string",
          "description": "Describes how the hashes are ordered when building the Merkle tree."
        },
        "description": {
          "type": "string",
          "description": "Additional details or notes about the hash computation method."
        }
      },
      "additionalProperties": false
    }
  }
}