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# SignatureErc8010.assert

:::info
`SignatureErc8010.assert` is a re-export of ox's [`SignatureErc8010.assert`](https://oxlib.sh/ercs/erc8010/SignatureErc8010/assert). Refer to the ox documentation for the full reference.
:::

Asserts that the wrapped signature is valid.

## Imports

```ts
import { SignatureErc8010 } from 'viem/utils'
```

## Examples

```ts twoslash
// @noErrors
import { SignatureErc8010 } from 'viem/utils'

SignatureErc8010.assert('0xdeadbeef')
// @error: InvalidWrappedSignatureError: Value `0xdeadbeef` is an invalid ERC-8010 wrapped signature.
```

## Definition

```ts
function assert(
  value: Unwrapped | Wrapped,
): void
```

## Parameters

### value

* **Type:** `Unwrapped | Wrapped`

The value to assert.

#### value.authorization

* **Type:** `{ address: abitype_Address; chainId: number; nonce: bigint; r: 0x${string}; s: 0x${string}; yParity: number; }`

Authorization signed by the delegatee.

#### value.data

* **Type:** `0x${string}`
* **Optional**

Data to initialize the delegation.

#### value.signature

* **Type:** `0x${string}`

The original signature.

#### value.to

* **Type:** `Address.Address | undefined`
* **Optional**

Address of the initializer.

## Return Type

`void`