API reference › @evolu/common › Type › optional

function optional<T>(type: T): OptionalType<T>;

Defined in: packages/common/src/Type.ts:4354

Optional Type.

Marks a Type as optional, meaning:

• If the value is present, it must match the given Type.
• If the value is absent, it is not included in the final object.

This is different from undefinedOr, which allows explicit undefined but still requires the key to exist.

Example:

const Todo = object({
  id: TodoId,
  title: NonEmptyString1000,
  isCompleted: optional(SqliteBoolean),
});