--- canonical: https://amplience.com/developers/docs/schema-reference/validation/ title: Validation description: Use the Amplience schema reference validation keywords to define rules for the valid values that authors can enter for properties when creating content. audience: Developer date_published: 2022-07-12 date_modified: 2026-05-10 --- # Validation The values authors can enter for a specific property can be constrained using validation keywords. These validation keywords can be used individually or combined. ```json { "type": "object", "properties": { "name": { "type": "string", //highlight-start "minLength": 0, "maxLength": 50 //highlight-end } }, //highlight-start "required": ["name"] //highlight-end } ``` They can be used anywhere a value type is defined in the schema, including properties and array items. ```json { "type": "array", "items": { "type": "string", //highlight-start "minLength": 0, "maxLength": 50 //highlight-end } } ``` Below is a summary of the available validation keywords | Validation Type | Description | | ------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | [Enumerated values](#enumerated-values) | Restricts the value to a fixed set of possible values. Properties using this validation will display as a dropdown.
`{"enum": ["red", "blue", "green"]}` `{"enum": [1,2,3]}` | | [Constant values](#constant-values) | Restricts the value to a constant value. Users will be unable to change the value in the authoring interface.
`{"const": "BannerComponent"}` | | [Regular expression](#regular-expression) | Validates the format of text values matches a custom regular expression
`{"pattern": "[a-z]+"}` | | [Text minimum length](#text-minimum-length) | Validates the minimum length of a text value
`{"minLength": 1}` | | [Text maximum length](#text-maximum-length) | Validates the maximum length of a text value
`{"maxLength": 50}` | | [Text format](#text-format) | Validates the format of text values matches the specified built-in format
`{"format": "date"}` see [below](#text-format) for a full list of formats | | [Number minimum value](#minimum-value) | Validates that the value entered is more than or equal to the minimum value.
`{"minimum": 0}` or `{"exclusiveMinimum": 0}` for just more than | | [Number maximum value](#maximum-value) | Validates that the value entered is less than or equal to maximum value.
`{"maximum": 10}` or `{"exclusiveMaximum": 0}` for just less than | | [Number multiple](#multiple) | Validates that the value entered is a multiple of the multipleOf value
`{"multipleOf": 2}` | | [Required properties](#required-properties) | Validates that the specified properties must be populated.
`{"properties": {"name": {"type": "string"}}, "required": ["name"]}` | | [Array minimum items](#array-minimum-items) | Validates that the Array value contains at least the minimum number of items
`{"minItems": 1}` | | [Array maximum items](#array-maximum-items) | Validates that the Array value does not contain more than the maximum number of items
`{"maxItems": 1}` | | [Array unique items](#array-unique-items) | Validates that every item in the Array is unique
`{"uniqueItems": true}` | ## Generic ### Enumerated values ```json { "type": "string", "enum": ["small", "medium", "large"] } ``` `✅ "small"` `❌ "xlarge"` ```json { "type": "number", "enum": [2, 4, 8, 16] } ``` `✅ 2` `❌ 3` The `enum` keyword restricts the values users can select to a fixed list. Properties using this validation will display as a dropdown. ### Constant values ```json { "properties": { "component": { "type": "string", "const": "BannerComponent" } } } ``` The `const` keyword can be applied to any property to hard-code the value. Properties using this keyword will be automatically set to the `const` value and will be immutable. ## Strings ### Regular Expression ```json { "type": "string", "pattern": "^[a-zA-Z0-9_-]+$" } ``` `✅ "summer-sale"` `❌ "summer sale"` The `pattern` keyword can be applied to any `string` property to validate the value matches a custom regular expression. The `pattern` keyword must be a valid ECMA-262 regular expression. ### Text Minimum Length ```json { "type": "string", "minLength": 10 } ``` `✅ "hello world"` `❌ "hello"` The `minLength` keyword can be applied to any `string` property to validate the number of characters is greater than, or equal to, the value of the keyword. ### Text Maximum Length ```json { "type": "string", "maxLength": 10 } ``` `✅ "hello"` `❌ "hello world"` The `maxLength` keyword can be applied to any `string` property to validate the number of characters is less than, or equal to, the value of the keyword. ### Text Format ```json { "type": "string", "format": "date" } ``` The `format` keyword can be applied to any `string` property to validate common data formats that do not have a native JSON representation. The supported formats are detailed below: | Format | Description | | ------------------------- | -------------------------------------------------------------------------------------------------------------------------- | | `"color"` | RGB or RGBA color, e.g. `"rgb(255,255,255)"`. Will display as a color picker. | | `"date"` | [RFC 3339](https://www.rfc-editor.org/rfc/rfc3339#section-5.6) Date e.g. `"2018-11-20"` | | `"time"` | [RFC 3339](https://www.rfc-editor.org/rfc/rfc3339#section-5.6) Time e.g. `"20:20:39"` or `"20:20:39+00:00"` | | `"date-time"` | [RFC 3339](https://www.rfc-editor.org/rfc/rfc3339#section-5.6) Date-time e.g. `"2018-11-13T20:20:39+00:00"` | | `"markdown"` | Markdown rich text, e.g. `"# Heading 1"`. Will display as a rich text editor. | | `"uri"` | [RFC 3986](https://tools.ietf.org/html/rfc3986) URI, e.g. `"https://example.com/"` | | `"uri-reference"` | [RFC 3986](https://tools.ietf.org/html/rfc3986#section-4.1) URI Reference, e.g. `"../page"` | | `"uri-template"` | [RFC 6570](https://tools.ietf.org/html/rfc6570) URI template, e.g. `"http://example.com/search{?q,lang}"` | | `"email"` | [RFC 5321](https://tools.ietf.org/html/rfc5321#section-4.1.2) Internet email address, e.g. `"example@example.com"` | | `"hostname"` | [RFC 1123](https://datatracker.ietf.org/doc/html/rfc1123#section-2.1) Hostname, e.g. `"example.com"` | | `"ipv4"` | [RFC 2673](https://tools.ietf.org/html/rfc2673#section-3.2) V4 IP Address, e.g. `"192.168.16.1"` | | `"ipv6"` | [RFC 2373](https://tools.ietf.org/html/rfc2373#section-2.2) V6 IP Address, e.g. `"1080:0:0:0:8:800:200C:417A"` | | `"json-pointer"` | [RFC 6901](https://tools.ietf.org/html/rfc6901) JSON Pointer, e.g. `"/foo/bar"` | | `"relative-json-pointer"` | [Relative JSON Pointer](https://tools.ietf.org/html/draft-handrews-relative-json-pointer-01), e.g. `"0#"` | | `"regex"` | [ECMA 262](https://www.ecma-international.org/publications/files/ECMA-ST/Ecma-262.pdf) Regular expression, e.g. `"[a-z]+"` | ## Numbers ### Minimum value ```json { "type": "number", "minimum": 0 } ``` `✅ 0` `❌ -1` ```json { "type": "number", "exclusiveMinimum": 0 } ``` `✅ 1` `❌ 0` The `minimum` keyword can be applied to any `number` property to validate the value is greater than, or equal to, the value of the keyword. The `exclusiveMinimum` keyword can be applied to any `number` property to validate the value is greater than the value of the keyword. ### Maximum value ```json { "type": "number", "maximum": 100 } ``` `✅ 100` `❌ 101` ```json { "type": "number", "exclusiveMaximum": 100 } ``` `✅ 99` `❌ 100` The `maximum` keyword can be applied to any `number` property to validate the value is less than, or equal to, the value of the keyword. The `exclusiveMaximum` keyword can be applied to any `number` property to validate the value is less than the value of the keyword. ### Multiple ```json { "multipleOf": 2 } ``` `✅ 4` `❌ 3` The `multipleOf` keyword can be applied to any `number` property to validate the value is a multiple of the value of the keyword. ## Objects ### Required Properties ```json { "type": "object", "properties": { "title": { "type": "string" }, "sku": { "type": "string" } }, "required": ["title", "sku"] } ``` `✅ {"title": "Summer Dress", "sku": "xa83748"}` `❌ {"title": "Summer Dress"}` `❌ {"sku": "xa83748"}` The `required` keyword can be applied to any `object` property to validate the specified properties are populated. The `required` keyword must be an array containing a unique set of property names, which must correspond to a property defined in the `properties` object. ## Arrays ### Array minimum items ```json { "type": "Array", "items": { "type": "string" }, "minItems": 2 } ``` `✅ ["item 1", "item 2", "item 3"]` `✅ ["item 1", "item 2"]` `❌ ["item 1"]` The `minItems` keyword can be applied to any `array` property to validate the length of the array is greater than, or equal to, the value of the keyword. ### Array maximum items ```json { "type": "Array", "items": { "type": "string" }, "maxItems": 2 } ``` `✅ ["item 1"]` `✅ ["item 1", "item 2"]` `❌ ["item 1", "item 2", "item 3"]` The `maxItems` keyword can be applied to any `array` property to validate the length of the array is less than, or equal to, the value of the keyword. ### Array unique items ```json { "type": "Array", "items": { "type": "string" }, "uniqueItems": true } ``` `✅ ["item 1", "item 2"]` `❌ ["item 1", "item 1"]` The `uniqueItems` keyword can be applied to any `array` property to validate the items inside the array are unique. ### Array contains Contains allows you to specify that an array must contain at least one item that matches specified schema. This can include a number which is greater than or equal to a specified amount, a string greater than a specified length, or a string equal to a value defined in a `const`. The example below shows the use of `contains` to validate two array properties. ```json "properties": { "numberArray": { "title": "Number array", "description": "An array of numbers", "type": "array", "minItems": 0, "maxItems": 10, "items": { "type": "number" }, "contains": { "type": "number", "minimum": 10 } }, "stringArray": { "title": "String array", "description": "An array of strings", "type": "array", "minItems": 0, "maxItems": 10, "items": { "type": "string" }, "contains": { "type": "string", "minLength": 10 } } } ```