Bitcoin Extend Format JavaScript Utils

Table of Contents

• Bitcoin Extend Format JavaScript Utils
  • Table of Contents
  • What is Bitcoin Extended Format?
  • Installation
  • Usage
  • Usage with the BSV library
    • On the command line
  • How can I help?
    • Contributors ✨
  • License

What is Bitcoin Extended Format?

The bitcoin transaction format is the most efficient way of sending the information that is needed for a Bitcoin node to validate. The BIP for this format is BIP-239

Installation

Install the Bitcoin Extended Format library into your project:

$ npm install bitcoin-ef

or, with yarn

$ yarn add bitcoin-ef

or, install as a global cli tool

$ npm install -g bitcoin-ef

Usage

Here's the getting started with the Extended Format

import { StandardToExtended, ExtendedToStandard } from 'bitcoin-ef/bsv';

// hex encoded standard transaction
const tx = "..."; // hex or buffer
// the missing information from the inputs, in the correct order (!)
const inputs = [
  {
    lockingScript: "...", // hex or buffer
    satoshis: 1234
  },
  {
    lockingScript: "...", // hex or buffer
    satoshis: 5423
  }
];
// The StandardToExtended function accepts both a hex string or a buffer, and will return the same format as was given
const extendTransaction = StandardToExtended(tx, inputs);

// The ExtendedToStandard function accepts both a hex string or a buffer, and will return the same format as was given
const standardTransaction = ExtendedToStandard(extendTransaction);

Usage with the BSV library

import bsv from 'bsv';
import 'bitcoin-ef/bsv';

const tx = new bsv.Transaction()
  .from(utxo)
  .to(toAddress, 50000)
  .fee(150)
  .change(changeAddress)
  .sign(privateKey)

const txBuffer = tx.toExtended();
const txHex = tx.toExtended('hex');

or if you have problems with the above:

import bsv from 'bsv';
import { BSVToExtended } from 'bitcoin-ef/bsv';

const tx = new bsv.Transaction()
  .from(utxo)
  .to(toAddress, 50000)
  .fee(150)
  .change(changeAddress)
  .sign(privateKey)

const txBuffer = BSVToExtended(tx);
const txHex = BSVToExtended(tx, 'hex');

Or using common JS:

const bsv = require('bsv')
require('bitcoin-ef/bsv')

/*
const utxo = {
  txId: '83c6307ba22838e469545db27a193934576e753ff4c0288537cece4a06ad3d87',
  outputIndex: 0,
  script: '76a914117af07edf84bcd40950f46a8254f7f78d85243088ac',
  satoshis: 836486
}

const child = bsv.HDPrivateKey('xprv....')
  .deriveChild('m/0/0')

const privateKey = child.privateKey
console.log(privateKey.toString())

const toAddress = privateKey.toAddress().toString()
console.log(toAddress)

const tx = new bsv.Transaction()
  .from(utxo)
  .change(toAddress)
  .sign(privateKey)
*/

// This is the hex of the signed transaction that does NOT contain the previous output script and satoshis.
const tx = bsv.Transaction('0100000001873dad064acece378528c0f43f756e573439197ab25d5469e43828a27b30c683000000006b483045022100ff923348df29deedf3c08fcb1bb898f7304344931ba131a03f86beae43f67af7022049fff7207c1f1ee0074de743066e4d3c5aa636d6d019187879327c9c9f6b3cbf412102e7cf3fce2bc6bf4b9e8ef59fd2e4df7f79b5fd8d84cc6b05b8cb9066fdd81575ffffffff0126c30c00000000001976a914117af07edf84bcd40950f46a8254f7f78d85243088ac00000000')

// The following code is not necessary if you have created and signed the transaction using the bsv library.
tx.inputs[0].output = {
  script: bsv.Script('76a914117af07edf84bcd40950f46a8254f7f78d85243088ac'),
  satoshis: 836486
}

console.log(tx.toExtended('hex'))

On the command line

After installing the cli tool, you can use it like this:

$ bitcoin-ef --help

To convert an extended transaction to a standard transaction:

$ bitcoin-ef --to-standard <hex encoded extended transaction>

To convert a standard transaction to an extended transaction, you need to pass the missing information from the inputs, in the correct order (!):

$ bitcoin-ef --to-extended <hex encoded standard transaction> <json encoded inputs>

To automatically convert a standard transaction to an extended transaction, using the WhatsOnChain API for lookups. This is the default behaviour of the cli tool:

$ bitcoin-ef --enrich-standard <hex encoded standard transaction>
or
$ bitcoin-ef <hex encoded standard transaction>

How can I help?

All kinds of contributions are welcome 🙌! The most basic way to show your support is to star 🌟 the project, or to raise issues 💬. You can also support this project by becoming a sponsor on GitHub 👏

Contributors ✨

Thank you to these wonderful people (emoji key):

Simon Ordish 🚇 💻 🛡️

Siggi 🚇 💻 🛡️

This project follows the all-contributors specification.

License