SYNOPSIS

A simple module for creating, manipulating and signing Ethereum transactions.

CONTACT

Scrollback or #ethereumjs on freenode

INSTALL

npm install ethereumjs-tx

USAGE

var Tx = require('ethereumjs-tx');
var privateKey = new Buffer('e331b6d69882b4cb4ea581d88e0b604039a3de5967688d3dcffdd2270c0fd109', 'hex');

var rawTx = {
  nonce: '00',
  gasPrice: '09184e72a000', 
  gasLimit: '2710',
  to: '0000000000000000000000000000000000000000', 
  value: '00', 
  data: '7f7465737432000000000000000000000000000000000000000000000000000000600057'
};

var tx = new Tx(rawTx);
tx.sign(privateKey);

var serializedTx = tx.serialize();

BOWSER

For standalone use in the browser inculde ./dist/ethereumjs-tx.js
This will give you a gobal varible EthTx to use. It will also create the globals Buffer and ethUtil
To build for standalone use in the browser install browserify and run npm run build.

API

• Transaction
  • new Transaction([data])
  • Transaction Properties
  • Transaction Methods
    • transaction.serialize()
    • transaction.hash([signature])
    • transaction.sign(privateKey)
    • transaction.getSenderAddress()
    • transaction.getSenderPublicKey()
    • transaction.validate()
    • transaction.validateSignature()
    • transaction.getDataFee()
    • transaction.getBaseFee()
    • transaction.getUpfrontCost()
    • transaction.toJSON([object])

Transaction

Implements schema and functions relating to Ethereum transactions

• example

new Transaction([data])

Creates a new transaction object

• data - a transaction can be initiailized with either a buffer containing the RLP serialized transaction or an array of buffers relating to each of the tx Properties, listed in order below. For example.

var rawTx = {
  nonce: '00',
  gasPrice: '09184e72a000', 
  gasLimit: '2710',
  to: '0000000000000000000000000000000000000000', 
  value: '00', 
  data: '7f7465737432000000000000000000000000000000000000000000000000000000600057',
  v: '1c', 
  r: '5e1d3a76fbf824220eafc8c79ad578ad2b67d01b0c2425eb1f1347e8f50882ab',
  s '5bd428537f05f9830e93792f90ea6a3e2d1ee84952dd96edbae9f658f831ab13'
};

var tx = new Transaction(rawTx);

Or lastly an Object containing the Properties of the transaction like in the Usage example

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

transaction Properties

• raw - The raw rlp decoded transaction.
• nonce
• to - the to address
• value - the amount of ether sent
• data - this will contain the data of the message or the init of a contract.
• v - EC signature parameter
• r - EC signature parameter
• s - EC recovery ID

Transaction Methods

transaction.serialize()

Returns the RLP serialization of the transaction
Return: 32 Byte Buffer

transaction.hash([signature])

Returns the SHA3-256 hash of the rlp transaction
Parameters

• signature - a Boolean determining if to include the signature components of the transaction. Defaults to true.

Return: 32 Byte Buffer

transaction.sign(privateKey)

Signs the transaction with the given privateKey.
Parameters

• privateKey - a 32 Byte Buffer

transaction.getSenderAddress()

Returns the senders address
Return: 20 Byte Buffer

transaction.getSenderPublicKey()

returns the public key of the sender
Return: Buffer

transaction.validate()

Determines if the transaction is schematicly valid by checking its signature and gasCost.
Return: Boolean

transaction.validateSignature()

Determines if the signature is valid
Return: Boolean

transaction.getDataFee()

Returns the amount of gas to be paid for the data in this transaction
Return: bn.js

transaction.getBaseFee()

Returns the minimum amount of gas the tx must have (DataFee + TxFee)
Return: bn.js

transaction.getUpfrontCost()

The total amount needed in the account of the sender for the transaction to be valid
Return: bn.js

transaction.toJSON([object])

Returns transaction as JSON
Parameters

• object - a Boolean that defaults to false. If object is true then this will return an object else it will return an array

Return: Object or Array

TESTS

test uses mocha. To run
npm test