{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://example.com/schemas/_defs.json",
  "title": "Common Definitions",
  "$defs": {
    "imageAsset": {
      "type": "object",
      "additionalProperties": false,
      "required": ["url", "alt"],
      "properties": {
        "url": { "type": "string", "format": "uri" },
        "alt": { "type": "string" },
        "width": { "type": "integer", "minimum": 1 },
        "height": { "type": "integer", "minimum": 1 },
        "mime": { "type": "string" }
      }
    },
    "attachment": {
      "type": "object",
      "additionalProperties": false,
      "required": ["label", "url"],
      "properties": {
        "label": { "type": "string" },
        "url": { "type": "string", "format": "uri" },
        "mime": { "type": "string" }
      }
    },
    "source": {
      "type": "object",
      "additionalProperties": false,
      "required": ["title", "url"],
      "properties": {
        "id": { "type": "string" },
        "title": { "type": "string" },
        "publisher": { "type": "string" },
        "url": { "type": "string", "format": "uri" },
        "date_accessed": { "type": "string", "format": "date" }
      }
    }
  }
}