{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://www.w3.org/TR/sparql11-results-json/sparql-results.json",
  "title": "SPARQL Query Results JSON Format",
  "description": "JSON Schema for the SPARQL 1.1 Query Results JSON Format as defined by the W3C Recommendation. Covers SELECT query results with variable bindings and ASK query boolean results.",
  "$defs": {
    "SelectResults": {
      "type": "object",
      "title": "SPARQL SELECT Results",
      "description": "Results of a SPARQL SELECT query containing a head with variable names and a results object with an array of bindings.",
      "required": ["head", "results"],
      "properties": {
        "head": {
          "$ref": "#/$defs/Head"
        },
        "results": {
          "$ref": "#/$defs/Results"
        }
      },
      "additionalProperties": false
    },
    "AskResult": {
      "type": "object",
      "title": "SPARQL ASK Result",
      "description": "Result of a SPARQL ASK query containing a head and a boolean value indicating whether the query pattern matches.",
      "required": ["head", "boolean"],
      "properties": {
        "head": {
          "$ref": "#/$defs/Head"
        },
        "boolean": {
          "type": "boolean",
          "description": "True if the query pattern has at least one solution, false otherwise."
        }
      },
      "additionalProperties": false
    },
    "Head": {
      "type": "object",
      "title": "Results Head",
      "description": "Header section of the SPARQL results containing variable names and optional metadata links.",
      "properties": {
        "vars": {
          "type": "array",
          "description": "Ordered list of variable names (without the leading '?') from the SELECT clause.",
          "items": {
            "type": "string",
            "pattern": "^[a-zA-Z_][a-zA-Z0-9_]*$"
          }
        },
        "link": {
          "type": "array",
          "description": "Array of URIs providing additional metadata about the results.",
          "items": {
            "type": "string",
            "format": "uri"
          }
        }
      }
    },
    "Results": {
      "type": "object",
      "title": "Results Body",
      "description": "Contains the array of solution bindings for a SELECT query.",
      "required": ["bindings"],
      "properties": {
        "bindings": {
          "type": "array",
          "description": "Array of solution mappings. Each element maps variable names to RDF term descriptions.",
          "items": {
            "$ref": "#/$defs/Binding"
          }
        }
      },
      "additionalProperties": false
    },
    "Binding": {
      "type": "object",
      "title": "Solution Binding",
      "description": "A single query solution mapping variable names to their bound RDF term values. Variables with no binding for a given solution are omitted.",
      "additionalProperties": {
        "$ref": "#/$defs/RdfTerm"
      }
    },
    "RdfTerm": {
      "title": "RDF Term",
      "description": "An RDF term value in the SPARQL results, representing an IRI, literal, or blank node.",
      "oneOf": [
        { "$ref": "#/$defs/IriTerm" },
        { "$ref": "#/$defs/LiteralTerm" },
        { "$ref": "#/$defs/BlankNodeTerm" }
      ]
    },
    "IriTerm": {
      "type": "object",
      "title": "IRI Term",
      "description": "An RDF IRI (Internationalized Resource Identifier) reference.",
      "required": ["type", "value"],
      "properties": {
        "type": {
          "type": "string",
          "const": "uri",
          "description": "Indicates this term is an IRI."
        },
        "value": {
          "type": "string",
          "format": "uri",
          "description": "The IRI value."
        }
      },
      "additionalProperties": false
    },
    "LiteralTerm": {
      "type": "object",
      "title": "Literal Term",
      "description": "An RDF literal value, optionally with a language tag or datatype IRI.",
      "required": ["type", "value"],
      "properties": {
        "type": {
          "type": "string",
          "enum": ["literal", "typed-literal"],
          "description": "Indicates this term is a literal. 'typed-literal' is used for backward compatibility."
        },
        "value": {
          "type": "string",
          "description": "The lexical form of the literal."
        },
        "xml:lang": {
          "type": "string",
          "description": "Language tag (BCP 47) for language-tagged literals.",
          "pattern": "^[a-zA-Z]{1,8}(-[a-zA-Z0-9]{1,8})*$"
        },
        "datatype": {
          "type": "string",
          "format": "uri",
          "description": "Datatype IRI for typed literals (e.g., xsd:integer, xsd:dateTime)."
        }
      },
      "additionalProperties": false
    },
    "BlankNodeTerm": {
      "type": "object",
      "title": "Blank Node Term",
      "description": "An RDF blank node with a locally-scoped identifier.",
      "required": ["type", "value"],
      "properties": {
        "type": {
          "type": "string",
          "const": "bnode",
          "description": "Indicates this term is a blank node."
        },
        "value": {
          "type": "string",
          "description": "A blank node identifier, scoped to the results document."
        }
      },
      "additionalProperties": false
    }
  },
  "oneOf": [
    { "$ref": "#/$defs/SelectResults" },
    { "$ref": "#/$defs/AskResult" }
  ]
}