Fields

Fields define the shape of your resource data. Each field has a name, a type, and optional properties that control validation, sorting, search, and automatic value generation.

Field Types

Snaapi supports 10 field types:

Type	Description
`string`	Short text value (up to database column limit)
`number`	Numeric value (integer or floating-point)
`boolean`	`true` or `false`
`json`	Arbitrary JSON object or array
`datetime`	ISO 8601 date-time string
`timestamp`	Unix timestamp (numeric)
`uuid`	UUID v4 string
`text`	Long-form text (unlimited length)
`enum`	One of a predefined set of string values
`relation`	Foreign key reference to another resource

Enum Fields

Enum fields must include an enumValues array listing every allowed value:

{
  "name": "status",
  "type": "enum",
  "enumValues": ["draft", "published", "archived"]
}

Relation Fields

Relation fields must include a relations object specifying the target resource, field, and relation type. See the Relations documentation for details.

Field Properties

Properties control how a field behaves within a resource:

Property	Type	Default	Description
`required`	boolean	`false`	Whether the field must be provided on create
`sortable`	boolean	`false`	Whether the field can be used in sort operations
`searchable`	boolean	`false`	Whether the field is included in full-text search
`unique`	boolean	`false`	Whether values must be unique across all records
`defaultValue`	any	—	Value used when the field is omitted on create

Additional optional metadata:

description — Human-readable description (up to 500 characters)
displayName — Label for UI rendering (up to 200 characters)
contentType — Semantic hint for UI and data generation (see Content Types)

Validation Rules

You can attach validation rules to string and number fields via the validations array. Each rule is checked at write time.

String Validations

Rule	Parameters	Description
`minLength`	`value` (number)	Minimum character count
`maxLength`	`value` (number)	Maximum character count
`regex`	`pattern`, optional `flags`	Must match the regular expression
`email`	—	Must be a valid email address
`url`	—	Must be a valid URL
`startsWith`	`value` (string)	Must start with the given prefix
`endsWith`	`value` (string)	Must end with the given suffix
`includes`	`value` (string)	Must contain the given substring

Number Validations

Rule	Parameters	Description
`minValue`	`value` (number)	Minimum allowed value (inclusive)
`maxValue`	`value` (number)	Maximum allowed value (inclusive)
`integer`	—	Must be a whole number

Example

{
  "name": "username",
  "type": "string",
  "required": true,
  "unique": true,
  "validations": [
    { "rule": "minLength", "value": 3 },
    { "rule": "maxLength", "value": 30 },
    { "rule": "regex", "pattern": "^[a-zA-Z0-9_]+$" }
  ]
}

Generation Transforms

A field can be automatically generated from another field at write time using the generatedFrom configuration. This is useful for deriving slugs, normalized values, or prefixed identifiers.

Transform	Description
`slug`	Converts the source value to a URL-friendly slug
`lowercase`	Converts the source value to lowercase
`uppercase`	Converts the source value to uppercase
`trim`	Removes leading and trailing whitespace
`prefix`	Prepends a fixed string (set via `prefix` option)
`suffix`	Appends a fixed string (set via `suffix` option)

Configuration

{
  "name": "slug",
  "type": "string",
  "generatedFrom": {
    "sourceField": "title",
    "transform": "slug"
  }
}

The sourceField must reference another field in the same resource. The optional prefix and suffix strings (up to 200 characters each) are applied after the transform.