bitcoinjs-lib

What is bitcoinjs-lib?

The bitcoinjs-lib npm package is a library for Bitcoin-related operations in JavaScript. It provides tools for creating, signing, and verifying Bitcoin transactions, as well as generating and managing Bitcoin addresses and keys.

What are bitcoinjs-lib's main functionalities?

Generate a Bitcoin Address

This feature allows you to generate a new Bitcoin address. The code creates a random key pair and derives a Bitcoin address from the public key.

const bitcoin = require('bitcoinjs-lib');
const keyPair = bitcoin.ECPair.makeRandom();
const { address } = bitcoin.payments.p2pkh({ pubkey: keyPair.publicKey });
console.log(address);

Create a Bitcoin Transaction

This feature allows you to create a Bitcoin transaction. The code builds a transaction by adding inputs and outputs, and then signs it with the private key.

const bitcoin = require('bitcoinjs-lib');
const keyPair = bitcoin.ECPair.fromWIF('your-private-key');
const txb = new bitcoin.TransactionBuilder();
txb.addInput('previous-txid', 0); // Add input (previous transaction)
txb.addOutput('recipient-address', 100000); // Add output (recipient address and amount in satoshis)
txb.sign(0, keyPair); // Sign the transaction
const tx = txb.build().toHex();
console.log(tx);

Verify a Bitcoin Transaction

This feature allows you to verify a Bitcoin transaction. The code parses a transaction from its hexadecimal representation and checks if all inputs have valid scripts.

const bitcoin = require('bitcoinjs-lib');
const tx = bitcoin.Transaction.fromHex('transaction-hex');
const txb = bitcoin.TransactionBuilder.fromTransaction(tx);
const isValid = txb.inputs.every(input => input.script && input.script.length > 0);
console.log(isValid);

Other packages similar to bitcoinjs-lib

bitcore-lib

Bitcore-lib is another JavaScript library for Bitcoin-related operations. It offers similar functionalities to bitcoinjs-lib, such as creating and signing transactions, generating addresses, and managing keys. Bitcore-lib is part of the Bitcore project, which includes additional tools and services for Bitcoin development.

bcoin

Bcoin is a full Bitcoin node implementation in JavaScript. It provides a comprehensive set of tools for Bitcoin development, including wallet management, transaction creation, and blockchain interaction. Bcoin is more feature-rich compared to bitcoinjs-lib, as it can run as a full node and participate in the Bitcoin network.

bitcoin-core

Bitcoin-core is a JavaScript library for interacting with Bitcoin Core, the reference implementation of the Bitcoin protocol. It allows developers to communicate with a Bitcoin Core node using RPC calls, enabling functionalities such as transaction creation, address management, and blockchain querying. Unlike bitcoinjs-lib, which is a standalone library, bitcoin-core relies on a running Bitcoin Core node.

README

BitcoinJS (bitcoinjs-lib)

The pure JavaScript Bitcoin library for node.js and browsers. Estimated to be in use by over 15 million wallet users and is the backbone for almost all Bitcoin web wallets in production today.

Features

• Clean: Pure JavaScript, concise code, easy to read.
• Tested: Coverage > 90%, third-party integration tests.
• Careful: Two person approval process for small, focused pull requests.
• Compatible: Works on Node.js and all modern browsers.
• Powerful: Support for advanced features, such as multi-sig, HD Wallets.
• Secure: Strong random number generation, PGP signed releases, trusted developers.
• Principled: No support for browsers with crap RNG (IE < 11)
• Standardized: Node community coding style, Browserify, Node's stdlib and Buffers.
• Fast: Optimized code, uses typed arrays instead of byte arrays for performance.
• Experiment-friendly: Bitcoin Mainnet and Testnet support.
• Altcoin-ready: Capable of working with bitcoin-derived cryptocurrencies (such as Dogecoin).

Should I use this in production?

If you are thinking of using the master branch of this library in production, stop. Master is not stable; it is our development branch, and only tagged releases may be classified as stable.

Installation

npm install bitcoinjs-lib

Setup

Node.js

var bitcoin = require('bitcoinjs-lib')

Browser

If you're familiar with how to use browserify, ignore this and proceed normally. These steps are advisory only, and may not be suitable for your application.

Browserify is assumed to be installed for these steps.

For your project, create an index.js file

let bitcoin = require('bitcoinjs-lib')

// your code here
function myFunction () {
	return bitcoin.ECPair.makeRandom().toWIF()
}

module.exports = {
	myFunction
}

Now, to compile for the browser:

browserify index.js --standalone foo > app.js

You can now put <script src="app.js" /> in your web page, using foo.myFunction to create a new Bitcoin private key.

NOTE: If you uglify the javascript, you must exclude the following variable names from being mangled: BigInteger, ECPair, Point. This is because of the function-name-duck-typing used in typeforce.

Example:

uglifyjs ... --mangle --reserved 'BigInteger,ECPair,Point'

NOTE: This library tracks Node LTS features, if you need strict ES5, use --transform babelify in conjunction with your browserify step (using an es2015 preset).

NOTE: If you expect this library to run on an iOS 10 device, ensure that you are using buffer@5.0.5 or greater.

Typescript or VSCode users

Type declarations for Typescript are available for version ^3.0.0 of the library.

npm install @types/bitcoinjs-lib

You can now use bitcoinjs-lib as a typescript compliant library.

import { HDNode, Transaction } from 'bitcoinjs-lib'

For VSCode (and other editors), users are advised to install the type declarations, as Intellisense uses that information to help you code (autocompletion, static analysis).

Report any typescript related bugs at @dlebrecht DefinitelyTyped fork, submit PRs to DefinitelyTyped

Flow

Definitions for Flow typechecker are available in flow-typed repository.

You can either download them directly from the repo, or with the flow-typed CLI

# npm install -g flow-typed
$ flow-typed install -f 0.27 bitcoinjs-lib@2.2.0 # 0.27 for flow version, 2.2.0 for bitcoinjs-lib version

The definitions are complete and up to date with version 2.2.0. The definitions are maintained by @runn1ng.

Examples

The below examples are implemented as integration tests, they should be very easy to understand. Otherwise, pull requests are appreciated. Some examples interact (via HTTPS) with a 3rd Party Blockchain Provider (3PBP).

• Generate a random address
• Generate an address from a SHA256 hash
• Import an address via WIF
• Generate a 2-of-3 P2SH multisig address
• Generate a SegWit address
• Generate a SegWit P2SH address
• Generate a SegWit 3-of-4 multisig address
• Generate a SegWit 2-of-2 P2SH multisig address
• Support the retrieval of transactions for an address (3rd party blockchain)
• Generate a Testnet address
• Generate a Litecoin address
• Create a 1-to-1 Transaction
• Create a 2-to-2 Transaction
• Create (and broadcast via 3PBP) a typical Transaction
• Create (and broadcast via 3PBP) a Transaction with an OP_RETURN output
• Create (and broadcast via 3PBP) a Transaction with a 2-of-4 P2SH(multisig) input
• Create (and broadcast via 3PBP) a Transaction with a SegWit P2SH(P2WPKH) input
• Create (and broadcast via 3PBP) a Transaction with a SegWit 3-of-4 P2SH(P2WSH(multisig)) input
• Import a BIP32 testnet xpriv and export to WIF
• Export a BIP32 xpriv, then import it
• Export a BIP32 xpub
• Create a BIP32, bitcoin, account 0, external address
• Create a BIP44, bitcoin, account 0, external address
• Create a BIP49, bitcoin testnet, account 0, external address
• Use BIP39 to generate BIP32 addresses
• Create (and broadcast via 3PBP) a Transaction where Alice can redeem the output after the expiry
• Create (and broadcast via 3PBP) a Transaction where Alice and Bob can redeem the output at any time
• Create (but fail to broadcast via 3PBP) a Transaction where Alice attempts to redeem before the expiry
• Recover a private key from duplicate R values
• Recover a BIP32 parent private key from the parent public key, and a derived, non-hardened child private key
• Generate a single-key stealth address
• Generate a single-key stealth address (randomly)
• Recover parent recipient.d, if a derived private key is leaked (and nonce was revealed)
• Generate a dual-key stealth address
• Generate a dual-key stealth address (randomly)

If you have a use case that you feel could be listed here, please ask for it!

Projects utilizing BitcoinJS

• BitAddress
• Blockchain.info
• Blocktrail
• Dark Wallet
• DecentralBank
• Dogechain Wallet
• EI8HT Wallet
• GreenAddress
• Helperbit
• Melis Wallet
• Robocoin
• Skyhook ATM

Contributing

We are always accepting of pull requests, but we do adhere to specific standards in regards to coding style, test driven development and commit messages.

Please make your best effort to adhere to these when contributing to save on trivial corrections.

Running the test suite

npm test
npm run-script coverage

Complementing Libraries

• BIP21 - A BIP21 compatible URL encoding utility library
• BIP38 - Passphrase-protected private keys
• BIP39 - Mnemonic generation for deterministic keys
• BIP32-Utils - A set of utilities for working with BIP32
• BIP66 - Strict DER signature decoding
• BIP69 - Lexicographical Indexing of Transaction Inputs and Outputs
• Base58 - Base58 encoding/decoding
• Base58 Check - Base58 check encoding/decoding
• Bech32 - A BIP173 compliant Bech32 encoding library
• coinselect - A fee-optimizing, transaction input selection module for bitcoinjs-lib.
• merkle-lib - A performance conscious library for merkle root and tree calculations.
• minimaldata - A module to check bitcoin policy: SCRIPT_VERIFY_MINIMALDATA

Alternatives

• BCoin
• Bitcore
• Cryptocoin

LICENSE MIT

Changelog

3.3.1

changed

• Increased the TransactionBuilder maximumFeeRate from 1000 to 2500 satoshis/byte. (#931)