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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 serializedTransaction = await walletClient.signTransaction(request)
const hash = await walletClient.sendRawTransaction({ serializedTransaction })

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 serializedTransaction = await walletClient.signTransaction(request)
const hash = await walletClient.sendRawTransaction({ serializedTransaction })

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)

The access list.

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

blobs (optional)

  • Type: Hex[]

Blobs for Blob Transactions.

import * as kzg from 'c-kzg'
import { toBlobs, stringToHex } from 'viem'
import { mainnetTrustedSetupPath } from 'viem/node'
 
const kzg = setupKzg(cKzg, mainnetTrustedSetupPath) 
 
const request = await walletClient.prepareTransactionRequest({
  account,
  blobs: toBlobs({ data: stringToHex('blobby blob!') }), 
  kzg,
  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') 
})

kzg (optional)

  • Type: KZG

KZG implementation for Blob Transactions.

See setupKzg for more information.

import * as kzg from 'c-kzg'
import { toBlobs, stringToHex } from 'viem'
import { mainnetTrustedSetupPath } from 'viem/node'
 
const kzg = setupKzg(cKzg, mainnetTrustedSetupPath) 
 
const request = await walletClient.prepareTransactionRequest({
  account,
  blobs: toBlobs({ data: stringToHex('blobby blob!') }), 
  kzg, 
  to: '0x70997970c51812dc3a010c7d01b50e0d17dc79c8'
})

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
})