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. Used by over a million wallet users and 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 necessary for your application.

Browserify is assumed to be installed for these steps.

From your repository, create an index.js file

module.exports = {
  base58: require('bs58'),
  bitcoin: require('bitcoinjs-lib'),
  ecurve: require('ecurve'),
  BigInteger: require('bigi'),
  Buffer: require('buffer')
}

Install each of the above packages locally

npm install bs58 bitcoinjs-lib ecurve bigi buffer

After installation, use browserify to compile index.js for use in the browser:

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

You will now be able to use <script src="app.js" /> in your browser, with each of the above exports accessible via the global foo object (or whatever you chose for the --standalone parameter above).

NOTE: See our package.json for the currently supported version of browserify used by this repository.

NOTE: When uglifying the javascript, you must exclude the following variable names from being mangled: Array, BigInteger, Boolean, Buffer, ECPair, Function, Number, Point and Script. This is because of the function-name-duck-typing used in typeforce. Example:

uglifyjs ... --mangle --reserved 'Array,BigInteger,Boolean,Buffer,ECPair,Function,Number,Point'

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.

• Generate a random address
• Generate a address from a SHA256 hash
• Generate a address and WIF for Litecoin
• Import an address via WIF
• Create a Transaction
• Sign a Bitcoin message
• Verify a Bitcoin message
• Create an OP RETURN transaction
• Create a 2-of-3 multisig P2SH address
• Spend from a 2-of-4 multisig P2SH address
• Generate a single-key stealth address
• Generate a dual-key stealth address
• Recover a BIP32 parent private key from the parent public key and a derived non-hardened child private key
• Recover a Private key from duplicate R values in a signature
• Create a CLTV locked transaction where the expiry is past
• Create a CLTV locked transaction where the parties bypass the expiry
• Create a CLTV locked transaction which fails due to expiry in the future

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
• Robocoin
• Skyhook ATM

Contributors

Stefan Thomas is the inventor and creator of this project. His pioneering work made Bitcoin web wallets possible. Daniel Cousens, Wei Lu, JP Richardson and Kyle Drake lead the major refactor of the library from 0.1.3 to 1.0.0.

Since then, many people have contributed. Click here to see the comprehensive list.

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
• BIP32-Wallet - A BIP32 Wallet backed by bitcoinjs-lib, lite on features but heavily tested
• BIP66 - Strict DER signature decoding
• BIP69 - Lexicographical Indexing of Transaction Inputs and Outputs
• Base58 - Base58 encoding/decoding
• Base58 Check - Base58 check encoding/decoding
• BCoin - BIP37 / Bloom Filters / SPV client
• insight - A bitcoin blockchain API for web wallets.

Alternatives

• Bitcore
• Cryptocoin

LICENSE MIT

Copyright

BitcoinJS (c) 2011-2016 bitcoinjs-lib contributors

Released under MIT license

Changelog

2.3.0

added

• Added HDNode.prototype.isNeutered (#536)
• Added HDNode.prototype.derivePath (#538)
• Added typeforce checking for HDNode.prototype.derive* (#539)
• Added Transaction.prototype.isCoinbase (#578)
• Added Block.prototype.checkMerkleRoot (#580)
• Added Block.calculateMerkleRoot (#580)
• Added TransactionBuilder.prototype.setVersion (#599)
• Added script.isWitnessPubKeyHashOutput (#602)
• Added script.isWitnessScriptHashOutput (#602)
• Added script.witnessPubKeyHashOutput (#602)
• Added script.witnessScriptHashOutput (#602)
• Added script.witnessScriptHashInput (#602)

fixed

• Fixed "BIP32 is undefined" when network list given to HDNode but no compatible version found (#550)
• Fixed writePushDataInt output to adhere to minimal data push policy (#617)