{
  "$id": "opml-subscription-list-schema.json",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "OPML 2.0 Subscription List",
  "description": "Schema describing an OPML 2.0 document modeling a feed reader subscription list. Each outline element with type='rss' references a feed via xmlUrl and (optionally) the corresponding human-readable site via htmlUrl. OPML 2.0 is specified at http://opml.org/spec2.opml.",
  "type": "object",
  "required": [
    "version",
    "head",
    "body"
  ],
  "properties": {
    "version": {
      "type": "string",
      "const": "2.0",
      "description": "OPML version. This schema targets OPML 2.0."
    },
    "head": {
      "type": "object",
      "description": "Metadata about the OPML document.",
      "properties": {
        "title": {
          "type": "string",
          "description": "Title of the document — typically the subscription list owner's name."
        },
        "dateCreated": {
          "type": "string",
          "description": "RFC 822 date the document was created."
        },
        "dateModified": {
          "type": "string",
          "description": "RFC 822 date the document was last modified."
        },
        "ownerName": {
          "type": "string"
        },
        "ownerEmail": {
          "type": "string",
          "format": "email"
        },
        "ownerId": {
          "type": "string",
          "format": "uri"
        },
        "docs": {
          "type": "string",
          "format": "uri",
          "default": "http://opml.org/spec2.opml"
        },
        "expansionState": {
          "type": "string",
          "description": "Comma-separated list of outline line numbers that should be expanded when the outline is shown."
        },
        "vertScrollState": {
          "type": "integer"
        },
        "windowTop": {
          "type": "integer"
        },
        "windowLeft": {
          "type": "integer"
        },
        "windowBottom": {
          "type": "integer"
        },
        "windowRight": {
          "type": "integer"
        }
      }
    },
    "body": {
      "type": "object",
      "description": "Container for the outline tree.",
      "required": [
        "outline"
      ],
      "properties": {
        "outline": {
          "type": "array",
          "minItems": 1,
          "items": {
            "$ref": "#/$defs/outline"
          }
        }
      }
    }
  },
  "$defs": {
    "outline": {
      "type": "object",
      "description": "An outline node. For subscription lists, leaf outlines have type='rss' and an xmlUrl pointing to the feed. Outlines may nest to model folders.",
      "required": [
        "text"
      ],
      "properties": {
        "text": {
          "type": "string",
          "description": "Required label displayed for the outline."
        },
        "type": {
          "type": "string",
          "description": "Outline type. Use 'rss' for subscription-list feed entries; 'link' for hyperlinks; other types per OPML 2.0.",
          "examples": [
            "rss",
            "link"
          ]
        },
        "title": {
          "type": "string",
          "description": "Human-readable feed title."
        },
        "xmlUrl": {
          "type": "string",
          "format": "uri",
          "description": "URL of the RSS, Atom, or JSON Feed document. REQUIRED when type='rss'."
        },
        "htmlUrl": {
          "type": "string",
          "format": "uri",
          "description": "URL of the human-readable website corresponding to the feed."
        },
        "description": {
          "type": "string"
        },
        "language": {
          "type": "string"
        },
        "version": {
          "type": "string",
          "description": "Feed format version (e.g., 'RSS2', 'ATOM').",
          "examples": [
            "RSS2"
          ]
        },
        "category": {
          "type": "string",
          "description": "Comma-separated list of category slash-strings (e.g., '/Technology/API')."
        },
        "created": {
          "type": "string",
          "description": "RFC 822 date the outline was created."
        },
        "isComment": {
          "type": "boolean",
          "default": false
        },
        "isBreakpoint": {
          "type": "boolean",
          "default": false
        },
        "outline": {
          "type": "array",
          "description": "Child outlines (for nested folders).",
          "items": {
            "$ref": "#/$defs/outline"
          }
        }
      },
      "allOf": [
        {
          "if": {
            "properties": {
              "type": {
                "const": "rss"
              }
            },
            "required": [
              "type"
            ]
          },
          "then": {
            "required": [
              "xmlUrl"
            ]
          }
        }
      ],
      "additionalProperties": true
    }
  },
  "additionalProperties": true
}