# GuardFunction

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

Guard function type.

## Generics

- `TInput` `extends any`

## Definition

- `GuardFunction` `(input: TInput) => input is any`