# OptionalSchemaAsync

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

Optional schema async interface.

## Generics

- `TWrapped` `extends BaseSchema<unknown, unknown, BaseIssue<unknown>> | BaseSchemaAsync<unknown, unknown, BaseIssue<unknown>>`
- `TDefault` `extends DefaultAsync<TWrapped, undefined>`

## Definition

- `OptionalSchemaAsync` `BaseSchemaAsync<InferInput<TWrapped> | undefined, InferOptionalOutput<TWrapped, TDefault>, InferIssue<TWrapped>>`
  - `type` `'optional'`
  - `reference` `typeof optional | typeof optionalAsync`
  - `expects` `` `(${TWrapped['expects']} | undefined)` ``
  - `wrapped` `TWrapped`
  - `default` `TDefault`