# TransactionEnvelope.assert

Asserts a [`TransactionEnvelope.TxEnvelope`](/api/TransactionEnvelope/types#txenvelope) is valid.

## Imports

:::code-group
```ts [Named]
import { TransactionEnvelope } from 'ox'
```

```ts [Entrypoint]
import * as TransactionEnvelope from 'ox/TransactionEnvelope'
```
:::

## Examples

```ts twoslash
import { TransactionEnvelope } from 'ox'

TransactionEnvelope.assert({
  chainId: 1,
  maxFeePerGas: 1n,
  type: 'eip1559'
})
```

## Definition

```ts
function assert(
  envelope: TransactionEnvelope.TxEnvelope,
): void
```

**Source:** [src/core/TxEnvelope.ts](https://github.com/wevm/ox/blob/main/src/core/TxEnvelope.ts#L141)

## Parameters

### envelope

* **Type:** [`TransactionEnvelope.TxEnvelope`](/api/TransactionEnvelope/types#transactionenvelopetxenvelope)

The transaction envelope to assert.

#### envelope.accessList

* **Type:** `readonly { address: abitype_Address; storageKeys: readonly 0x${string}[]; }[]`
* **Optional**

EIP-2930 Access List.

#### envelope.authorizationList

* **Type:** `readonly { address: abitype_Address; chainId: numberType; nonce: bigintType; r: 0x${string}; s: 0x${string}; yParity: numberType; }[]`

EIP-7702 Authorization List.

#### envelope.blobVersionedHashes

* **Type:** `readonly 0x${string}[]`
* **Optional**

Versioned blob hashes.

#### envelope.chainId

* **Type:** `number | bigint`

Chain ID. Use bigint for IDs beyond the safe integer range.

#### envelope.data

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

Contract code or a hashed method call with encoded args

#### envelope.frames

* **Type:** `readonly Frame[]`

Frames to execute, in order.

#### envelope.from

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

Sender of the transaction. RPC-only metadata; not part of the
serialized envelope. Carried here for parity with
[`TransactionRequest.TransactionRequest`](/api/TransactionRequest/types#transactionrequest) and
[`Transaction.Transaction`](/api/Transaction/types#transaction).

#### envelope.gas

* **Type:** `bigintType`
* **Optional**

Gas provided for transaction execution

#### envelope.gasPrice

* **Type:** `bigintType`
* **Optional**

Base fee per gas.

#### envelope.input

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

#### envelope.maxFeePerBlobGas

* **Type:** `bigint`
* **Optional**

Maximum fee per blob gas, in wei.

#### envelope.maxFeePerGas

* **Type:** `bigint`
* **Optional**

Maximum fee per gas, in wei.

#### envelope.maxPriorityFeePerGas

* **Type:** `bigint`
* **Optional**

Maximum priority fee per gas, in wei.

#### envelope.nonce

* **Type:** `bigint`
* **Optional**

Sender nonce.

#### envelope.r

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

#### envelope.s

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

#### envelope.sender

* **Type:** `abitype_Address`

Account authorizing execution.

#### envelope.sidecars

* **Type:** `Sidecars`
* **Optional**

PeerDAS sidecars. Excluded from transaction and signing hashes.

#### envelope.signatures

* **Type:** `readonly FrameSignature[]`
* **Optional**

Signature entries, including unsigned placeholders before signing.

#### envelope.to

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

Transaction recipient

#### envelope.type

* **Type:** `"eip8141"`

Transaction type.

#### envelope.v

* **Type:** `numberType`
* **Optional**

#### envelope.value

* **Type:** `bigintType`
* **Optional**

Value in wei sent with this transaction

#### envelope.yParity

* **Type:** `numberType`
* **Optional**

ECDSA signature yParity.

## Return Type

`void`