bitcoinjs-lib/README.md

# BitcoinJS (bitcoinjs-lib)
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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](https://github.com/bitcoinjs/bitcoinjs-lib/tags).


## Installation
``` bash
npm install bitcoinjs-lib
```

## Setup
### Node.js
``` javascript
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](https://github.com/substack/node-browserify) is assumed to be installed for these steps.

From your repository, create an `index.js` file
``` javascript
module.exports = {
  base58: require('bs58'),
  bitcoin: require('bitcoinjs-lib'),
  ecurve: require('ecurve'),
  BigInteger: require('bigi')
}
```

Install each of the above packages locally
``` bash
npm install bs58 bitcoinjs-lib ecurve bigi
```

After installation, use browserify to compile `index.js` for use in the browser:
``` bash
    $ 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`, `ECPair`, `Function`, `Number`, `Point` and `Script`.
This is because of the function-name-duck-typing used in [typeforce](https://github.com/dcousens/typeforce).
Example:
``` bash
uglifyjs ... --mangle --reserved 'Array,BigInteger,Boolean,ECPair,Function,Number,Point'
```

**NOTE**: If you expect this library to run on an iOS 10 device, ensure that you are using [buffer@5.0.5](https://github.com/feross/buffer/pull/155) or greater.

### Flow
Definitions for [Flow typechecker](https://flowtype.org/) are available in flow-typed repository.

[You can either download them directly](https://github.com/flowtype/flow-typed/blob/master/definitions/npm/bitcoinjs-lib_v2.x.x/flow_v0.17.x-/bitcoinjs-lib_v2.x.x.js) 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](https://github.com/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](https://github.com/bitcoinjs/bitcoinjs-lib/blob/ae8422d/test/integration/addresses.js#L12)
- [Generate an address from a SHA256 hash](https://github.com/bitcoinjs/bitcoinjs-lib/blob/ae8422d/test/integration/addresses.js#L19)
- [Import an address via WIF](https://github.com/bitcoinjs/bitcoinjs-lib/blob/ae8422d/test/integration/addresses.js#L29)
- [Generate a 2-of-3 multisig P2SH address](https://github.com/bitcoinjs/bitcoinjs-lib/blob/ae8422d/test/integration/addresses.js#L36)
- [Support the retrieval of transactions for an address (3rd party blockchain)](https://github.com/bitcoinjs/bitcoinjs-lib/blob/ae8422d/test/integration/addresses.js#L52)
- [Generate a Testnet address](https://github.com/bitcoinjs/bitcoinjs-lib/blob/ae8422d/test/integration/addresses.js#L73)
- [Generate a Litecoin address](https://github.com/bitcoinjs/bitcoinjs-lib/blob/ae8422d/test/integration/addresses.js#L83)
- [Create a 1-to-1 Transaction](https://github.com/bitcoinjs/bitcoinjs-lib/blob/ae8422d/test/integration/transactions.js#L14)
- [Create a 2-to-2 Transaction](https://github.com/bitcoinjs/bitcoinjs-lib/blob/ae8422d/test/integration/transactions.js#L28)
- [Create (and broadcast via 3PBP) a typical Transaction](https://github.com/bitcoinjs/bitcoinjs-lib/blob/ae8422d/test/integration/transactions.js#L46)
- [Create (and broadcast via 3PBP) a Transaction with an OP\_RETURN output](https://github.com/bitcoinjs/bitcoinjs-lib/blob/ae8422d/test/integration/transactions.js#L88)
- [Create (and broadcast via 3PBP) a Transaction with a 2-of-4 multisig P2SH input](https://github.com/bitcoinjs/bitcoinjs-lib/blob/ae8422d/test/integration/transactions.js#L115)
- [Import a BIP32 testnet xpriv and export to WIF](https://github.com/bitcoinjs/bitcoinjs-lib/blob/ae8422d/test/integration/bip32.js#L8)
- [Export a BIP32 xpriv, then import it](https://github.com/bitcoinjs/bitcoinjs-lib/blob/ae8422d/test/integration/bip32.js#L15)
- [Export a BIP32 xpub](https://github.com/bitcoinjs/bitcoinjs-lib/blob/ae8422d/test/integration/bip32.js#L26)
- [Create a BIP32, bitcoin, account 0, external address](https://github.com/bitcoinjs/bitcoinjs-lib/blob/ae8422d/test/integration/bip32.js#L35)
- [Create a BIP44, bitcoin, account 0, external address](https://github.com/bitcoinjs/bitcoinjs-lib/blob/ae8422d/test/integration/bip32.js#L50)
- [Create a BIP49, bitcoin testnet, account 0, external address](https://github.com/bitcoinjs/bitcoinjs-lib/blob/ae8422d/test/integration/bip32.js#L66)
- [Use BIP39 to generate BIP32 addresses](https://github.com/bitcoinjs/bitcoinjs-lib/blob/ae8422d/test/integration/bip32.js#L83)
- [Create (and broadcast via 3PBP) a Transaction where Alice can redeem the output after the expiry](https://github.com/bitcoinjs/bitcoinjs-lib/blob/ae8422d/test/integration/cltv.js#L37)
- [Create (and broadcast via 3PBP) a Transaction where Alice and Bob can redeem the output at any time](https://github.com/bitcoinjs/bitcoinjs-lib/blob/ae8422d/test/integration/cltv.js#L71)
- [Create (but fail to broadcast via 3PBP) a Transaction where Alice attempts to redeem before the expiry](https://github.com/bitcoinjs/bitcoinjs-lib/blob/ae8422d/test/integration/cltv.js#L104)
- [Recover a private key from duplicate R values](https://github.com/bitcoinjs/bitcoinjs-lib/blob/ae8422d/test/integration/crypto.js#L14)
- [Recover a BIP32 parent private key from the parent public key, and a derived, non-hardened child private key](https://github.com/bitcoinjs/bitcoinjs-lib/blob/ae8422d/test/integration/crypto.js#L115)
- [Generate a single-key stealth address](https://github.com/bitcoinjs/bitcoinjs-lib/blob/ae8422d/test/integration/stealth.js#L70:)
- [Generate a single-key stealth address (randomly)](https://github.com/bitcoinjs/bitcoinjs-lib/blob/ae8422d/test/integration/stealth.js#L89:)
- [Recover parent recipient.d, if a derived private key is leaked (and nonce was revealed)](https://github.com/bitcoinjs/bitcoinjs-lib/blob/ae8422d/test/integration/stealth.js#L105)
- [Generate a dual-key stealth address](https://github.com/bitcoinjs/bitcoinjs-lib/blob/ae8422d/test/integration/stealth.js#L122)
- [Generate a dual-key stealth address (randomly)](https://github.com/bitcoinjs/bitcoinjs-lib/blob/ae8422d/test/integration/stealth.js#L145)

If you have a use case that you feel could be listed here, please [ask for it](https://github.com/bitcoinjs/bitcoinjs-lib/issues/new)!


## Projects utilizing BitcoinJS
- [BitAddress](https://www.bitaddress.org)
- [Blockchain.info](https://blockchain.info/wallet)
- [Blocktrail](https://www.blocktrail.com/)
- [Dark Wallet](https://www.darkwallet.is/)
- [DecentralBank](http://decentralbank.com/)
- [Dogechain Wallet](https://dogechain.info)
- [EI8HT Wallet](http://ei8.ht/)
- [GreenAddress](https://greenaddress.it)
- [Melis Wallet](https://melis.io)
- [Robocoin](https://wallet.robocoin.com)
- [Skyhook ATM](http://projectskyhook.com)


## 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

``` bash
npm test
npm run-script coverage
```

## Complementing Libraries
- [BIP21](https://github.com/bitcoinjs/bip21) - A BIP21 compatible URL encoding utility library
- [BIP38](https://github.com/bitcoinjs/bip38) - Passphrase-protected private keys
- [BIP39](https://github.com/bitcoinjs/bip39) - Mnemonic generation for deterministic keys
- [BIP32-Utils](https://github.com/bitcoinjs/bip32-utils) - A set of utilities for working with BIP32
- [BIP66](https://github.com/bitcoinjs/bip66) - Strict DER signature decoding
- [BIP69](https://github.com/bitcoinjs/bip69) - Lexicographical Indexing of Transaction Inputs and Outputs
- [Base58](https://github.com/cryptocoinjs/bs58) - Base58 encoding/decoding
- [Base58 Check](https://github.com/bitcoinjs/bs58check) - Base58 check encoding/decoding
- [Bech32](https://github.com/bitcoinjs/bech32) - A BIP173 compliant Bech32 encoding library
- [coinselect](https://github.com/bitcoinjs/coinselect) - A fee-optimizing, transaction input selection module for bitcoinjs-lib.
- [merkle-lib](https://github.com/bitcoinjs/merkle-lib) - A performance conscious library for merkle root and tree calculations.
- [minimaldata](https://github.com/bitcoinjs/minimaldata) - A module to check bitcoin policy: SCRIPT_VERIFY_MINIMALDATA


## Alternatives
- [BCoin](https://github.com/indutny/bcoin)
- [Bitcore](https://github.com/bitpay/bitcore)
- [Cryptocoin](https://github.com/cryptocoinjs/cryptocoin)


## LICENSE [MIT](LICENSE)