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# Prf.tag

:::info
`Prf.tag` is a re-export of ox's [`Prf.tag`](https://oxlib.sh/api/Prf/tag). Refer to the ox documentation for the full reference.
:::

Creates a credential-bound PRF configuration from a UTF-8 tag.

Tags are public, stable identifiers. Use the same tag with the same credential to reproduce a PRF output.

## Imports

```ts
import { Prf } from 'viem/utils'
```

## Examples

```ts twoslash
// @noErrors
import { Prf, WebAuthn } from 'viem/utils'

const credential = await WebAuthn.getCredential({
  credentialId: 'oZ48...',
  prf: Prf.tag('account.1')
})
```

## Definition

```ts
function tag(
  value: string,
): tag.ReturnType
```

## Parameters

### value

* **Type:** `string`

Tag to encode.

## Return Type

A credential-bound PRF configuration.

`tag.ReturnType`