Ethereumtx

ES5 compliant transaction builder for Ethereum

Getting Started

This module allows to create, sign and verify raw transactions in Ethereum.

It also supports creating new accounts and transforming private keys to public keys and addresses.

This package was written to give an easy interface to manually creating Ethereum transactions, just like the bitcoin-cli does for Bitcoin.

Installing

npm install ethereumtx

Running the tests

npm test

Example

const ethtx = require('ethereumtx')

/*
  Create a new account with
  var account = ethtx.getnewaddress();
*/
var privateKey = '17d08f5fe8c77af811caa0c9a187e668ce3b74a99acc3f6d976f075fa8e0be55';

const txParams = {
  nonce: '0x4',
  gasPrice: '0x4a817c800',
  gasLimit: '0xdbba0',
  to: '0xd6e4caea206c9e58187cf129eeaa61b600b483bc',
  value: '0x4000'
};

var rawtx = ethtx.createrawtransaction(txParams);
console.log(rawtx);
/*
{ rawtransaction: 'e7048504a817c800830dbba094d6e4caea206c9e58187cf129eeaa61b600b483bc824000801c8080',
  chainId: 1 }
  // Mainnet chainId: 1 (default)
*/
var signedtx = ethtx.signrawtransaction(rawtx.rawtransaction, privateKey, rawtx.chainId);
console.log(signedtx);
/*
{ Signature:
   Signature {
     r: <BN: 910197c43da82517ad24882788d06428add58d6414c52fc712f432fb6067a36a>,
     s: <BN: 6165ea97f7d85d8403b1b4be07bf89d79980e48732a6c60e22b0f0a16270a6a9>,
     recoveryParam: 0 },
  signedTx: 'f867048504a817c800830dbba094d6e4caea206c9e58187cf129eeaa61b600b483bc8240008025a0910197c43da82517ad24882788d06428add58d6414c52fc712f432fb6067a36aa06165ea97f7d85d8403b1b4be07bf89d79980e48732a6c60e22b0f0a16270a6a9' }
*/
var validTransaction = ethtx.verifyrawtransaction(signedtx.signedTx, privateKey);
console.log(validTransaction);
/*
{ valid: true }
*/
var txParamDecoded = ethtx.decoderawtransaction(signedtx.signedTx);
console.log(txParamDecoded)
/*
{ nonce: '04',
  gasPrice: '04a817c800',
  gasLimit: '0dbba0',
  to: 'd6e4caea206c9e58187cf129eeaa61b600b483bc',
  value: '4000',
  data: '',
  v: '25',
  r: '910197c43da82517ad24882788d06428add58d6414c52fc712f432fb6067a36a',
  s: '6165ea97f7d85d8403b1b4be07bf89d79980e48732a6c60e22b0f0a16270a6a9' }
*/

API Reference

For all functions having chainId as parameter. The parameter is optional and defaults to 1. See EIP155

createrawtransaction(txParams, [chainId])

Create a raw transaction using the given transaction parameters and the chainId.

Parameters

• txParams JSON
• privateKey string
• chainId integer (Optional, defaults to 1), can get overridden if the v value of the txParams is set, read EIP 155

Returns

• JSON including the raw transaction and the chain id

Example

{ rawtransaction: 'e7048504a817c800830dbba094d6e4caea206c9e58187cf129eeaa61b600b483bc824000801c8080',
  chainId: 1 }

decoderawtransaction(tx)

Decodes raw transaction back to json with transaction parameters

Parameters

• tx string raw transaction

Returns

• JSON with transaction parameters

Example

{ nonce: '04',
  gasPrice: '04a817c800',
  gasLimit: '0dbba0',
  to: 'd6e4caea206c9e58187cf129eeaa61b600b483bc',
  value: '4000',
  data: '',
  v: '25',
  r: '910197c43da82517ad24882788d06428add58d6414c52fc712f432fb6067a36a',
  s: '6165ea97f7d85d8403b1b4be07bf89d79980e48732a6c60e22b0f0a16270a6a9' }

signrawtransaction(tx, privateKey, [chainId])

Sign a raw transaction with a given private key. The transaction is going to be deployed on a network with id chainId. (See EIP155)

Parameters

• tx string
• privateKey string
• chainId integer (Optional, defaults to 1)

Returns

• JSON with 'signature' and 'signedTx' (signed transaction)

Example

{ Signature:
   Signature {
     r: <BN: 910197c43da82517ad24882788d06428add58d6414c52fc712f432fb6067a36a>,
     s: <BN: 6165ea97f7d85d8403b1b4be07bf89d79980e48732a6c60e22b0f0a16270a6a9>,
     recoveryParam: 0 },
  signedTx: 'f867048504a817c800830dbba094d6e4caea206c9e58187cf129eeaa61b600b483bc8240008025a0910197c43da82517ad24882788d06428add58d6414c52fc712f432fb6067a36aa06165ea97f7d85d8403b1b4be07bf89d79980e48732a6c60e22b0f0a16270a6a9' }

verifyrawtransaction(tx, privateKey, [chainId])

Verifies that a transaction tx was signed with private key privateKey. On failure it also returns the error.

Parameters

• tx string
• privateKey string
• chainId integer (Optional, defaults to 1)

Returns JSON with fields 'valid' and 'error'

Examples

{'valid': true, 'error': ''}
{'valid': false, 'error': 'Not signed by privateKey: 17d08f5fe8c77af811caa0c9a187e668ce3b74a99acc3f6d976f075fa8e0be55'}

getnewaddress()

Generates a new pseudorandom private key, public key and address

Returns

Example

{ privateKey: 'f29bffee46a37afaf549bfcd0f6166a55042de53ff8261e1b2eace48b5e39c91',
  publicKey: '2f65b9d0c967b623a9d3de5dc405d4a0133f60be6af7751d1b0ac112bb3180c045633c1dbfce97bc02f87cd441e5eed9be52605520b7fd7a4beab9641313ac82',
  address: '27eda7afbbb3694e0a5a1af0a93d583a35c31273' }

privateToPublic(privateKey)

Converts private key to public

Parameters

• privateKey string

Returns

• publicKey string

publicToAddress(pubKey)

Converts public key to address

Parameters

• publicKey string

Returns

• address string

getFields()

Returns the fields of a transaction

Authors

• Panayiotis Panayiotou - panpan2

License

This project is licensed under the MIT License - see the LICENSE.md file for details