ethereumjs-account

What is ethereumjs-account?

The ethereumjs-account package is a JavaScript library for managing Ethereum accounts. It provides functionalities for creating, manipulating, and serializing Ethereum accounts, making it easier to handle account-related operations in Ethereum-based applications.

What are ethereumjs-account's main functionalities?

Creating a new account

This feature allows you to create a new Ethereum account. The code sample demonstrates how to create a new account instance using the Account class from the ethereumjs-account package.

const { Account } = require('ethereumjs-account');
const newAccount = new Account();
console.log(newAccount);

Serializing an account

This feature allows you to serialize an Ethereum account into a buffer. The code sample shows how to serialize an account and convert it to a hexadecimal string.

const { Account } = require('ethereumjs-account');
const account = new Account();
const serialized = account.serialize();
console.log(serialized.toString('hex'));

Deserializing an account

This feature allows you to deserialize a buffer back into an Ethereum account. The code sample demonstrates how to deserialize a hexadecimal string buffer into an account instance.

const { Account } = require('ethereumjs-account');
const serialized = Buffer.from('...', 'hex');
const account = Account.deserialize(serialized);
console.log(account);

Updating account balance

This feature allows you to update the balance of an Ethereum account. The code sample shows how to set the balance of an account to 2 ETH (in wei).

const { Account } = require('ethereumjs-account');
const account = new Account();
account.balance = '0x1bc16d674ec80000'; // 2 ETH in wei
console.log(account.balance.toString('hex'));

Other packages similar to ethereumjs-account

web3

The web3 package is a comprehensive library for interacting with the Ethereum blockchain. It includes functionalities for managing accounts, sending transactions, and interacting with smart contracts. Compared to ethereumjs-account, web3 offers a broader range of features but may be more complex to use for simple account management tasks.

ethers

The ethers package is another popular library for interacting with the Ethereum blockchain. It provides utilities for managing wallets, sending transactions, and interacting with smart contracts. Ethers is known for its simplicity and ease of use, making it a good alternative to ethereumjs-account for developers looking for a more user-friendly experience.

eth-lib

The eth-lib package is a lightweight library for Ethereum-related operations, including account management, transaction creation, and signing. It offers a more minimalistic approach compared to ethereumjs-account, making it suitable for developers who need basic functionalities without the overhead of a larger library.

README

SYNOPSIS

This library eases the handling of Ethereum accounts, where accounts can be either external accounts or contracts (see Account Types docs).

Note that the library is not meant to be used to handle your wallet accounts, use e.g. the web3-eth-personal package from the web3.js library for that. This is just a semantic wrapper to ease the use of account data and provide functionality for reading and writing accounts from and to the Ethereum state trie.

INSTALL

npm install ethereumjs-account

BROWSER

This module work with browserify.

API

• new Account([data])
• Account Properties
• Account Methods
  • account.isEmpty()
  • account.isContract()
  • account.serialize()
  • account.toJSON()
  • account.getCode(trie, cb)
  • account.setCode(trie, code, cb)
  • account.getStorage(trie, key, cb)
  • account.setStorage(trie, key, val, cb)

new Account([data])

Creates a new account object

• data - an account can be initialized with either a buffer containing the RLP serialized account. Or an Array of buffers relating to each of the account Properties, listed in order below. For example:

var raw = [ 
  '0x02', //nonce
  '0x0384', //balance
  '0x56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421', //stateRoot
  '0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470'  //codeHash
  ];

var account = new Account(raw);

Or lastly an Object containing the Properties of the account:

var raw = {
  nonce: '',
  balance: '0x03e7',
  stateRoot: '0x56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421',
  codeHash: '0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470'
};

var account = new Account(raw);

For Object and Array each of the elements can either be a Buffer, hex String, Number, or an object with a toBuffer method such as Bignum.

Account Properties

• nonce - The account's nonce.
• balance - The account's balance in wei.
• stateRoot - The stateRoot for the storage of the contract.
• codeHash - The hash of the code of the contract.

Account Methods

account.isEmpty()

Returns a Boolean determining if the account is empty.

account.isContract()

Returns a Boolean deteremining if the account is a contract.

account.serialize()

Returns the RLP serialization of the account as a Buffer.

account.toJSON([object])

Returns the account as JSON.

• object - A Boolean that defaults to false. If object is true then this will return an Object, else it will return an Array.

account.getCode(trie, cb)

Fetches the code from the trie.

• trie - The trie storing the accounts.
• cb - The callback.

account.setCode(trie, code, cb)

Stores the code in the trie.

• trie - The trie storing the accounts.
• code - A Buffer.
• cb - The callback.

Example for getCode and setCode:

// Requires manual merkle-patricia-tree install
const SecureTrie = require('merkle-patricia-tree/secure')
const Account = require('./index.js')

let code = Buffer.from('73095e7baea6a6c7c4c2dfeb977efac326af552d873173095e7baea6a6c7c4c2dfeb977efac326af552d873157', 'hex')

let raw = {
  nonce: '',
  balance: '0x03e7',
  stateRoot: '0x56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421',
  codeHash: '0xb30fb32201fe0486606ad451e1a61e2ae1748343cd3d411ed992ffcc0774edd4'
}

let account = new Account(raw)
let trie = new SecureTrie()

account.setCode(trie, code, function (err, codeHash) {
  console.log(`Code with hash 0x${codeHash.toString('hex')} set to trie`)
  account.getCode(trie, function (err, code) {
    console.log(`Code ${code.toString('hex')} read from trie`)
  })
})

account.getStorage(trie, key, cb)

Fetches key from the account's storage.

account.setStorage(trie, key, val, cb)

Stores a val at the key in the contract's storage.

Example for getStorage and setStorage:

// Requires manual merkle-patricia-tree install
const SecureTrie = require('merkle-patricia-tree/secure')
const Account = require('./index.js')

let raw = {
  nonce: '',
  balance: '0x03e7',
  stateRoot: '0x56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421',
  codeHash: '0xb30fb32201fe0486606ad451e1a61e2ae1748343cd3d411ed992ffcc0774edd4'
}

let account = new Account(raw)
let trie = new SecureTrie()

let key = Buffer.from('0000000000000000000000000000000000000000', 'hex')
let value = Buffer.from('01', 'hex')

account.setStorage(trie, key, value, function (err, value) {
  account.getStorage(trie, key, function (err, value) {
    console.log(`Value ${value.toString('hex')} set and retrieved from trie.`)
  })
})

Changelog

[2.0.5] - 2018-05-08

• Fixes a bug for contract code stored with level DB, PR #5
• Added safe-buffer dependency for backwards compatibility, PR #14
• Code examples in README for getCode/setCode and getStorage/setStorage, PR #19
• Added test coverage
• Updated dependencies