Data

This keyword uses values from data as schema values. Since it can be dangerous to allow arbitrary content inside a schema this keyword is restricted to the following keywords:

minLength, maxLength, pattern,

minimum, maximum, multipleOf, exclusiveMinimum, exclusiveMaximum,

minItems, maxItems, uniqueItems,

required, minProperties, maxProperties,

format, const, enum.

To use this keyword you must replace the value of the original keyword with an object having the following structure {"$data": "json-pointer"}. The value of the keyword will dynamically resolve to the value extracted by the JSON pointer.

{
  "type": "object",
  "properties": {
    "password": {
      "type": "string"
    },
    "repeat": {
      "type": "string",
      "const": {"$data": "/password"}
    }
  }
}

You can disable $data keyword by setting the allowDataKeyword option to false.