# UndefinedSchema

> This document is the Markdown version of [valibot.dev/api/UndefinedSchema/](https://valibot.dev/api/UndefinedSchema/). For the complete documentation index, see [llms.txt](https://valibot.dev/llms.txt).

Undefined schema interface.

## Generics

- `TMessage` `extends ErrorMessage<UndefinedIssue> | undefined`

## Definition

- `UndefinedSchema` `extends BaseSchema<undefined, undefined, UndefinedIssue>`
  - `type` `'undefined'`
  - `reference` `typeof undefined`
  - `expects` `'undefined'`
  - `message` `TMessage`