{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "object",
  "properties": {
    "schema_version": {
      "type": "string",
      "const": "1.0.0"
    },
    "asset_id": {
      "type": "string",
      "pattern": "^(?:[a-z0-9]+(?:-[a-z0-9]+)*\\/){3}[a-z0-9]+(?:-[a-z0-9]+)*$"
    },
    "url": {
      "type": "string",
      "format": "uri"
    },
    "sha256": {
      "type": "string",
      "pattern": "^sha256:[a-f0-9]{64}$"
    },
    "retrieved_at": {
      "type": "string",
      "format": "date-time",
      "pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d(?::[0-5]\\d(?:\\.\\d+)?)?(?:Z))$"
    },
    "availability": {
      "type": "string",
      "enum": [
        "available",
        "moved",
        "gone",
        "unchecked"
      ]
    },
    "last_checked_at": {
      "type": "string",
      "format": "date-time",
      "pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d(?::[0-5]\\d(?:\\.\\d+)?)?(?:Z))$"
    }
  },
  "required": [
    "schema_version",
    "asset_id",
    "url",
    "sha256",
    "retrieved_at",
    "availability"
  ],
  "additionalProperties": false
}