unevaluatedProperties : Schema

unevaluatedProperties

Schema

Validates object properties that did not successfully validate against other standard object applicators.

Value This keyword must be set to a valid JSON Schema Hint: Use the jsonschema metaschema and jsonschema lint commands to catch keywords set to invalid values
Kind Applicator Annotation
Applies To Object
Base Dialect 2019-09
Changed In None
Introduced In 2019-09
Vocabulary Applicator
Specification https://json-schema.org/draft/2019-09/draft-handrews-json-schema-02#rfc.section.9.3.2.4
Metaschema https://json-schema.org/draft/2019-09/meta/unevaluated
Official Tests draft2019-09/unevaluatedProperties.json
Default {}
Annotation Array The set of instance property names validated by this keyword's subschema Hint: Use the jsonschema validate command to collect annotations from the command-line
Affected By
Affects None
Also See

The unevaluatedProperties keyword is a generalisation of the additionalProperties keyword that considers related keywords even when they are not direct siblings of this keyword. More specifically, this keyword is affected by occurrences of properties, patternProperties, additionalProperties, and unevaluatedProperties itself, as long as the evaluate path that led to unevaluatedProperties is a prefix of the evaluate path of the others.

Given its evaluation-dependent nature, this keyword is evaluated after every other keyword from every other vocabulary.

Remember that JSON Schema is a constraint-driven language. Therefore, non-object instances successfully validate against this keyword. If needed, make use of the type keyword to constraint the accepted type accordingly.

Examples

A schema that conditionally constrains object instances to define certain properties, with string additional properties in both cases Schema 
{
  "$schema": "https://json-schema.org/draft/2019-09/schema",
  "if": { "maxProperties": 2 },
  "then": { "properties": { "foo": true } },
  "else": { "patternProperties": { "^@": true } },
  "unevaluatedProperties": { "type": "string" }
}
Valid An object value that defines a "foo" property and other string properties is valid Instance 
{ "foo": 1, "bar": "baz" }
Annotations 
{ "keyword": "/then/properties", "instance": "", "value": [ "foo" ] }
{ "keyword": "/unevaluatedProperties", "instance": "", "value": [ "bar" ] }
Valid An object value that defines multiple properties that start with "@" and other string properties is valid Instance 
{ "@foo": 1, "@bar": 2, "baz": "qux" }
Annotations 
{ "keyword": "/else/patternProperties", "instance": "", "value": [ "@foo", "@bar" ] }
{ "keyword": "/unevaluatedProperties", "instance": "", "value": [ "baz" ] }
Invalid An object value that defines a "foo" property and other non-string properties is invalid Instance 
{ "foo": 1, "bar": 2 }
Invalid An object value that defines multiple properties that start with "@" and other non-string properties is invalid Instance 
{ "@foo": 1, "@bar": 2, "baz": 3 }
Valid An empty object value is valid Instance 
{}
Valid A non-object value is valid Instance 
"Hello World"
A schema that constraints object instances to only allow extension keywords that start with "@" using a helper Schema 
{
  "$schema": "https://json-schema.org/draft/2019-09/schema",
  "properties": { "foo": true },
  "$ref": "#/$defs/allow-extensions",
  "unevaluatedProperties": false,
  "$defs": {
    "allow-extensions": {
      "patternProperties": { "^@": true }
    }
  }
}
Valid An object value that only defines a "foo" property is valid Instance 
{ "foo": 1 }
Annotations 
{ "keyword": "/properties", "instance": "", "value": [ "foo" ] }
Valid An object value that only defines a "foo" property and other properties that start with "@" is valid Instance 
{ "foo": 1, "@bar": 2, "@baz": 3 }
Annotations 
{ "keyword": "/properties", "instance": "", "value": [ "foo" ] }
{ "keyword": "/$defs/allow-extensions/patternProperties", "instance": "", "value": [ "@bar", "@baz" ] }
Valid An object value that only defines properties that start with "@" is valid Instance 
{ "@foo": 1, "@bar": 2, "@baz": 3 }
Annotations 
{ "keyword": "/$defs/allow-extensions/patternProperties", "instance": "", "value": [ "@foo", "@bar", "@baz" ] }
Invalid An object value that only defines a "foo" property and other properties that do not start with "@" is invalid Instance 
{ "foo": 1, "bar": 2 }
Valid An empty object value is valid Instance 
{}
Valid A non-object value is valid Instance 
"Hello World"
A schema that constraints object instances to not define any properties, as both object keywords are cousins Schema 
{
  "$schema": "https://json-schema.org/draft/2019-09/schema",
  "allOf": [
    { "properties": { "foo": true } },
    { "unevaluatedProperties": false }
  ]
}
Invalid An object value that only defines a "foo" property is invalid as the schema prohibits unevaluated properties Instance 
{ "foo": 1 }
Invalid An object value that defines any other property is invalid as the schema prohibits unevaluated properties Instance 
{ "bar": 2 }
Valid An empty object value is valid Instance 
{}
Valid A non-object value is valid Instance 
"Hello World"
A schema that constraints object instances to define arbitrary properties Schema 
{
  "$schema": "https://json-schema.org/draft/2019-09/schema",
  "allOf": [ { "unevaluatedProperties": true } ],
  "unevaluatedProperties": false
}
Valid An object value that defines any property is valid as the nested applicator takes precedence Instance 
{ "foo": 1, "bar": 2, "baz": 3 }
Annotations 
{ "keyword": "/allOf/0/unevaluatedProperties", "instance": "", "value": [ "foo", "bar", "baz" ] }
Valid An empty object value is valid Instance 
{}
Valid A non-object value is valid Instance 
"Hello World"