prepareTransactionRequest

Prepares a transaction request for signing by populating a nonce, gas limit, fee values, and a transaction type.

Usage

example.ts

import { account, walletClient } from './config'
 
const request = await walletClient.prepareTransactionRequest({ 
  account,
  to: '0x70997970c51812dc3a010c7d01b50e0d17dc79c8',
  value: 1000000000000000000n
})
{
   account: '0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266',
   to: '0x70997970C51812dc3A010C7d01b50e0d17dc79C8',
   maxFeePerGas: 150000000000n,
   maxPriorityFeePerGas: 1000000000n,
   nonce: 69,
   type: 'eip1559',
   value: 1000000000000000000n
 }
  
const signature = await walletClient.signTransaction(request)
const hash = await walletClient.sendRawTransaction(signature)

Account Hoisting

If you do not wish to pass an account to every prepareTransactionRequest, you can also hoist the Account on the Wallet Client (see config.ts).

Learn more.

example.ts

import { walletClient } from './config'
 
const request = await walletClient.prepareTransactionRequest({ 
  to: '0x70997970c51812dc3a010c7d01b50e0d17dc79c8',
  value: 1000000000000000000n
})
{
   account: '0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266',
   to: '0x70997970C51812dc3A010C7d01b50e0d17dc79C8',
   maxFeePerGas: 150000000000n,
   maxPriorityFeePerGas: 1000000000n,
   nonce: 69,
   type: 'eip1559',
   value: 1000000000000000000n
 }
  
const signature = await walletClient.signTransaction(request)
const hash = await walletClient.sendRawTransaction(signature)

Returns

TransactionRequest

The transaction request.

Parameters

account

Type: Account | Address

The Account to send the transaction from.

Accepts a JSON-RPC Account or Local Account (Private Key, etc).

const request = await walletClient.prepareTransactionRequest({
  account: '0xf39fd6e51aad88f6f4ce6ab8827279cfffb92266', 
  to: '0x70997970c51812dc3a010c7d01b50e0d17dc79c8',
  value: 1000000000000000000n
})

to

Type: 0x${string}

The transaction recipient or contract address.

const request = await walletClient.prepareTransactionRequest({
  account,
  to: '0x70997970c51812dc3a010c7d01b50e0d17dc79c8', 
  value: 1000000000000000000n,
  nonce: 69
})

accessList (optional)

Type: AccessList

The access list.

const request = await walletClient.prepareTransactionRequest({
  accessList: [ 
    {
      address: '0x1',
      storageKeys: ['0x1'],
    },
  ],
  account,
  to: '0x70997970c51812dc3a010c7d01b50e0d17dc79c8',
})

chain (optional)

Type: Chain
Default: walletClient.chain

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

The chain is also used to infer its request type (e.g. the Celo chain has a gatewayFee that you can pass through to prepareTransactionRequest).

import { optimism } from 'viem/chains'
 
const request = await walletClient.prepareTransactionRequest({
  chain: optimism, 
  account,
  to: '0x70997970c51812dc3a010c7d01b50e0d17dc79c8',
  value: 1000000000000000000n
})

data (optional)

Type: 0x${string}

A contract hashed method call with encoded args.

const request = await walletClient.prepareTransactionRequest({
  data: '0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2', 
  account,
  to: '0x70997970c51812dc3a010c7d01b50e0d17dc79c8',
  value: 1000000000000000000n
})

gasPrice (optional)

Type: bigint

The price (in wei) to pay per gas. Only applies to Legacy Transactions.

import { parseEther, parseGwei } from 'viem'
 
const request = await walletClient.prepareTransactionRequest({
  account,
  gasPrice: parseGwei('20'), 
  to: '0x70997970c51812dc3a010c7d01b50e0d17dc79c8',
  value: parseEther('1') 
})

maxFeePerGas (optional)

Type: bigint

Total fee per gas (in wei), inclusive of maxPriorityFeePerGas. Only applies to EIP-1559 Transactions

import { parseEther, parseGwei } from 'viem'
 
const request = await walletClient.prepareTransactionRequest({
  account,
  maxFeePerGas: parseGwei('20'),  
  to: '0x70997970c51812dc3a010c7d01b50e0d17dc79c8',
  value: parseEther('1')
})

maxPriorityFeePerGas (optional)

Type: bigint

Max priority fee per gas (in wei). Only applies to EIP-1559 Transactions

import { parseEther, parseGwei } from 'viem'
 
const request = await walletClient.prepareTransactionRequest({
  account,
  maxFeePerGas: parseGwei('20'),
  maxPriorityFeePerGas: parseGwei('2'), 
  to: '0x70997970c51812dc3a010c7d01b50e0d17dc79c8',
  value: parseEther('1')
})

nonce (optional)

Type: number

Unique number identifying this transaction.

const request = await walletClient.prepareTransactionRequest({
  account,
  to: '0x70997970c51812dc3a010c7d01b50e0d17dc79c8',
  value: 1000000000000000000n,
  nonce: 69
})

parameters (optional)

Type: ("fees" | "gas" | "nonce" | "type")[]
Default: ["fees", "gas", "nonce", "type"]

Parameters to prepare.

For instance, if ["gas", "nonce"] is provided, then only the gas and nonce parameters will be prepared.

const request = await walletClient.prepareTransactionRequest({
  account,
  to: '0x70997970c51812dc3a010c7d01b50e0d17dc79c8',
  value: 1000000000000000000n,
  nonce: 69
})

value (optional)

Type: bigint

Value in wei sent with this transaction.

import { parseEther } from 'viem'
 
const request = await walletClient.prepareTransactionRequest({
  account,
  to: '0x70997970c51812dc3a010c7d01b50e0d17dc79c8',
  value: parseEther('1'), 
  nonce: 69
})