{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "$id": "https://adcontextprotocol.org/schemas/3.2.0-beta.8/error-details/vast-version-mismatch.json",
  "title": "VAST Version Mismatch Details",
  "description": "Required compatibility details for VAST_VERSION_MISMATCH. Modern emitters discriminate an asset-versus-acceptance mismatch from an inspected-document mismatch. The legacy supported_versions-only arm remains accepted for older 3.x peers.",
  "type": "object",
  "properties": {
    "mismatch_reason": {
      "type": "string",
      "enum": [
        "asset_outside_acceptance",
        "document_version_mismatch"
      ],
      "description": "Machine-readable modern mismatch branch."
    },
    "asset_vast_version": {
      "$ref": "https://adcontextprotocol.org/schemas/3.2.0-beta.8/enums/vast-version.json"
    },
    "observed_document_vast_version": {
      "anyOf": [
        {
          "type": "string",
          "minLength": 1
        },
        {
          "type": "null"
        }
      ],
      "description": "Raw version observed on the inspected VAST document whose root is being validated. `null` means the required version attribute was missing. This field is intentionally not limited to the governed supported-version enum so diagnostics can report future or invalid document values."
    },
    "document_role": {
      "type": "string",
      "enum": [
        "submitted",
        "wrapper",
        "terminal_inline"
      ],
      "description": "Role of the inspected document. Only the submitted document is required to equal the asset declaration; wrapper and terminal documents are checked against the applicable acceptance sets."
    },
    "product_vast_versions": {
      "type": "array",
      "items": {
        "$ref": "https://adcontextprotocol.org/schemas/3.2.0-beta.8/enums/vast-version.json"
      },
      "minItems": 1,
      "uniqueItems": true
    },
    "seller_vast_versions": {
      "type": "array",
      "items": {
        "$ref": "https://adcontextprotocol.org/schemas/3.2.0-beta.8/enums/vast-version.json"
      },
      "minItems": 1,
      "uniqueItems": true
    },
    "format_option_ref": {
      "$ref": "https://adcontextprotocol.org/schemas/3.2.0-beta.8/core/format-option-ref.json",
      "description": "Selected option reference when the product option is addressable. Omitted for a unique id-less product option."
    },
    "supported_versions": {
      "type": "array",
      "items": {
        "$ref": "https://adcontextprotocol.org/schemas/3.2.0-beta.8/enums/vast-version.json"
      },
      "minItems": 1,
      "uniqueItems": true,
      "deprecated": true,
      "description": "Deprecated 3.x compatibility field. For an acceptance mismatch, this is the effective product/seller intersection when known. Modern emitters use the typed sets and mismatch_reason."
    }
  },
  "anyOf": [
    {
      "title": "Asset outside accepted version intersection",
      "properties": {
        "mismatch_reason": {
          "const": "asset_outside_acceptance"
        }
      },
      "required": [
        "mismatch_reason",
        "asset_vast_version",
        "product_vast_versions",
        "seller_vast_versions"
      ]
    },
    {
      "title": "Inspected document version mismatch",
      "properties": {
        "mismatch_reason": {
          "const": "document_version_mismatch"
        }
      },
      "required": [
        "mismatch_reason",
        "asset_vast_version",
        "observed_document_vast_version",
        "document_role"
      ],
      "allOf": [
        {
          "if": {
            "properties": {
              "document_role": {
                "enum": [
                  "wrapper",
                  "terminal_inline"
                ]
              }
            },
            "required": [
              "document_role"
            ]
          },
          "then": {
            "required": [
              "product_vast_versions",
              "seller_vast_versions"
            ]
          }
        }
      ]
    },
    {
      "title": "Supported versions compatibility details",
      "required": [
        "supported_versions"
      ],
      "not": {
        "required": [
          "mismatch_reason"
        ]
      }
    }
  ],
  "additionalProperties": true
}