# estimateInitiateWithdrawalGas

Estimates gas required to initiate a [withdrawal](https://github.com/ethereum-optimism/optimism/blob/develop/specs/deposits.md) on an L2 to the L1.

## Usage

:::code-group
```ts [example.ts]
import { base } from 'viem/chains'
import { account, publicClientL2 } from './config'
 
const gas = await publicClientL2.estimateInitiateWithdrawalGas({
  account,
  request: {
    gas: 21_000n,
    to: '0x70997970c51812dc3a010c7d01b50e0d17dc79c8',
    value: parseEther('1')
  },
})
```

```ts [config.ts]
import { createWalletClient, custom } from 'viem'
import { privateKeyToAccount } from 'viem/accounts'
import { mainnet } from 'viem/chains'
import { publicActionsL2 } from 'viem/op-stack'

export const publicClientL2 = createPublicClient({
  chain: mainnet,
  transport: custom(window.ethereum)
}).extend(publicActionsL2())

// JSON-RPC Account
export const [account] = await walletClientL2.getAddresses()
// Local Account
export const account = privateKeyToAccount(...)
```
:::

## Returns

`bigint`

Estimated gas required to initiate the withdrawal.

## Parameters

### account

* **Type:** `Account | Address`

The Account to send the transaction from.

Accepts a [JSON-RPC Account](/docs/clients/wallet#json-rpc-accounts) or [Local Account (Private Key, etc)](/docs/clients/wallet#local-accounts-private-key-mnemonic-etc).

```ts
const gas = await client.estimateInitiateWithdrawalGas({
  account: '0xf39fd6e51aad88f6f4ce6ab8827279cfffb92266', // [!code focus]
  request: {
    gas: 21_000n,
    to: '0x70997970c51812dc3a010c7d01b50e0d17dc79c8',
    value: parseEther('1')
  },
  targetChain: base,
})
```

### args.data (optional)

* **Type:** `Hex`

Encoded contract method & arguments.

```ts
const gas = await client.estimateInitiateWithdrawalGas({
  account: '0xf39fd6e51aad88f6f4ce6ab8827279cfffb92266',
  request: {
    data: '0x...', // [!code focus]
    gas: 21_000n,
    to: '0x70997970c51812dc3a010c7d01b50e0d17dc79c8', 
    value: parseEther('1')
  },
})
```

### args.gas

* **Type:** `bigint`

Gas limit for transaction execution on the L1.

```ts
const gas = await client.estimateInitiateWithdrawalGas({
  account: '0xf39fd6e51aad88f6f4ce6ab8827279cfffb92266',
  request: {
    gas: 21_000n, // [!code focus]
    to: '0x70997970c51812dc3a010c7d01b50e0d17dc79c8',
    value: parseEther('1')
  },
})
```

### args.to

* **Type:** `Address`

L1 Transaction recipient.

```ts
const gas = await client.estimateInitiateWithdrawalGas({
  account: '0xf39fd6e51aad88f6f4ce6ab8827279cfffb92266',
  request: {
    gas: 21_000n,
    to: '0x70997970c51812dc3a010c7d01b50e0d17dc79c8',  // [!code focus]
    value: parseEther('1')
  },
})
```

### args.value (optional)

* **Type:** `bigint`

Value in wei to withdrawal from the L2 to the L1. Debited from the caller's L2 balance.

```ts
const gas = await client.estimateInitiateWithdrawalGas({
  account: '0xf39fd6e51aad88f6f4ce6ab8827279cfffb92266',
  request: {
    gas: 21_000n,
    to: '0x70997970c51812dc3a010c7d01b50e0d17dc79c8', 
    value: parseEther('1') // [!code focus]
  },
})
```

### chain (optional)

* **Type:** [`Chain`](/docs/glossary/types#chain)
* **Default:** `client.chain`

The L2 chain. If there is a mismatch between the wallet's current chain & this chain, an error will be thrown.

```ts
import { optimism } from 'viem/chains'

const gas = await client.estimateInitiateWithdrawalGas({
  account: '0xf39fd6e51aad88f6f4ce6ab8827279cfffb92266',
  request: {
    gas: 21_000n,
    to: '0x70997970c51812dc3a010c7d01b50e0d17dc79c8', 
    value: parseEther('1')
  },
  chain: optimism, // [!code focus]
})
```

### maxFeePerGas (optional)

* **Type:** `bigint`

Total fee per gas (in wei), inclusive of `maxPriorityFeePerGas`.

```ts
const gas = await client.estimateInitiateWithdrawalGas({
  account: '0xf39fd6e51aad88f6f4ce6ab8827279cfffb92266',
  request: {
    gas: 21_000n,
    to: '0x70997970c51812dc3a010c7d01b50e0d17dc79c8', 
    value: parseEther('1')
  },
  maxFeePerGas: parseGwei('20'),  // [!code focus]
})
```

### maxPriorityFeePerGas (optional)

* **Type:** `bigint`

Max priority fee per gas (in wei). Only applies to [EIP-1559 Transactions](/docs/glossary/terms#eip-1559-transaction)

```ts
const gas = await client.estimateInitiateWithdrawalGas({
  account: '0xf39fd6e51aad88f6f4ce6ab8827279cfffb92266',
  request: {
    gas: 21_000n,
    to: '0x70997970c51812dc3a010c7d01b50e0d17dc79c8', 
    value: parseEther('1')
  },
  maxFeePerGas: parseGwei('20'), 
  maxPriorityFeePerGas: parseGwei('2'),  // [!code focus]
})
```

### nonce (optional)

* **Type:** `number`

Unique number identifying this transaction.

```ts
const gas = await client.estimateInitiateWithdrawalGas({
  account: '0xf39fd6e51aad88f6f4ce6ab8827279cfffb92266',
  request: {
    gas: 21_000n,
    to: '0x70997970c51812dc3a010c7d01b50e0d17dc79c8', 
    value: parseEther('1')
  },
  nonce: 69, // [!code focus]
})
```