BCoin

BCoin is a bitcoin node which can act as an SPV node or a fully validating fullnode. Bcoin runs in node.js, but it can also be browserified.

Features

• SPV mode
• HD Wallets (using BIP44 (or optionally BIP45) derivation)
• Fully browserifiable
• Full block validation
• Full block database
• Fully validating mempool (stored in-memory or on-disk)
• Wallet database
• HTTP server which acts as a wallet server and can also serve: blocks, txs (by hash/address), and utxos (by id/address).
  • Fast UTXO retrieval by address for wallets (10000 utxos from 10000 different addresses in ~700ms, 50000+ utxos from 10-100 addresses in ~400ms)
• Segregated witness support for block/tx validation and wallets.
• Versionbits suport.

Install

$ npm install bcoin

Documentation

Read the docs here: http://bcoin.io/docs/

Example Usage

• Creating a blockchain and mempool
• Connecting to the P2P network
• Doing and SPV sync
• High-level usage with the Node object
• Running a full node in the browser
• CLI Usage

Creating a blockchain and mempool

var bcoin = require('bcoin').set('regtest');
var chain = new bcoin.chain({ db: 'memory' });
var mempool = new bcoin.mempool({ chain: chain, db: 'memory' });
var miner = new bcoin.miner({ chain: chain, mempool: mempool });

// Create a block "attempt"
miner.open(function(err) {
  if (err)
    throw err;

  miner.createBlock(function(err, attempt) {
    if (err)
      throw err;

    // Mine the block on the worker pool (use mine() for the master process)
    attempt.mineAsync(function(err, block) {
      if (err)
        throw err;

      // Add the block to the chain
      chain.add(block, function(err) {
        if (err)
          throw err;

        console.log('Added %s to the blockchain.', block.rhash);
        console.log(block);
      });
    });
  });
});

Connecting to the P2P network

var bcoin = require('bcoin').set('main');

var chain = new bcoin.chain({ db: 'leveldb' });
var mempool = new bcoin.mempool({ chain: chain, db: 'memory' });
var pool = new bcoin.pool({ chain: chain, mempool: mempool, size: 8 });

pool.open(function(err) {
  if (err)
    throw err;

  // Connect, start retrieving and relaying txs
  pool.connect();

  // Start the blockchain sync.
  pool.startSync();

  chain.on('block', function(block) {
    console.log('Added block:');
    console.log(block);
  });

  mempool.on('tx', function(tx) {
    console.log('Added tx to mempool:');
    console.log(tx);
  });

  pool.on('tx', function(tx) {
    console.log('Saw transaction:');
    console.log(tx);
  });
});

// Start up a segnet4 sync while
// we're at it (because we can).

var tchain = new bcoin.chain({
  network: 'segnet4',
  db: 'memory'
});

var tmempool = new bcoin.mempool({
  network: 'segnet4',
  chain: tchain,
  db: 'memory'
});

var tpool = new bcoin.pool({
  network: 'segnet4',
  chain: tchain,
  mempool: tmempool,
  size: 8
});

tpool.open(function(err) {
  if (err)
    throw err;

  // Connect, start retrieving and relaying txs
  tpool.connect();

  // Start the blockchain sync.
  tpool.startSync();

  tchain.on('block', function(block) {
    console.log('Added segnet4 block:');
    console.log(block);
  });

  tmempool.on('tx', function(tx) {
    console.log('Added segnet4 tx to mempool:');
    console.log(tx);
  });

  tpool.on('tx', function(tx) {
    console.log('Saw segnet4 transaction:');
    console.log(tx);
  });
});

Doing an SPV sync

var bcoin = require('bcoin').set('testnet');

var chain = new bcoin.chain({
  db: 'leveldb',
  // A custom chaindb location:
  location: process.env.HOME + '/chain.db',
  spv: true
});

var pool = new bcoin.pool({
  chain: chain,
  spv: true,
  size: 8
});

var walletdb = new bcoin.walletdb({ db: 'memory' });

pool.open(function(err) {
  if (err)
    throw err;

  walletdb.open(function(err) {
    if (err)
      throw err;

    walletdb.create(function(err, wallet) {
      if (err)
        throw err;

      console.log('Created wallet with address %s', wallet.getAddress());

      // Add our address to the spv filter.
      pool.watchAddress(wallet.getAddress());

      // Connect, start retrieving and relaying txs
      pool.connect();

      // Start the blockchain sync.
      pool.startSync();

      pool.on('tx', function(tx) {
        wallet.addTX(tx);
      });

      wallet.on('balance', function(balance) {
        console.log('Balance updated.');
        console.log(bcoin.utils.btc(balance.unconfirmed));
      });
    });
  });
});

High-level usage with the Node object

var bcoin = require('bcoin').set('main');

var node = bcoin.fullnode({
  prune: false,
  useCheckpoints: true,
  debug: true,
  // Primary wallet passphrase
  passsphrase: 'node'
});

// Start the node
node.open(function(err) {
  if (err)
    throw err;

  // Create a new wallet (or get an existing one with the same ID)
  var options = {
    id: 'mywallet',
    passphrase: 'foo',
    witness: false,
    type: 'pubkeyhash'
  };

  node.createWallet(options, function(err, wallet) {
    if (err)
      throw err;

    console.log('Created wallet with address: %s', wallet.getAddress());

    // Start syncing the blockchain
    // (this will take a while since we're a fullnode)
    node.startSync();

    // Wait for balance and send it to a new address.
    wallet.once('balance', function(balance) {
      // Create a transaction, fill
      // it with coins, and sign it.
      var to = {
        address: newReceiving,
        value: balance.total
      };
      wallet.createTX({ subtractFee: true }, [to], function(err, tx) {
        if (err)
          throw err;

        wallet.sign(tx, function(err) {
          if (err)
            throw err;

          console.log('sending tx:');
          console.log(tx);

          node.sendTX(tx, function(err) {
            if (err) {
              // Could be a reject
              // packet or a timeout.
              return console.log(err);
            }
            console.log('tx sent!');
          });
        });
      });
    });
  });
});

node.chain.on('block', function(block) {
  console.log(block);
});

node.mempool.on('tx', function(tx) {
  console.log(block);
});

node.chain.on('full', function() {
  node.mempool.getAll(function(err, txs) {
    if (err)
      throw err;

    console.log(txs);
  });
});

Running a full node in the browser

$ cd ~/bcoin
$ make # Browserify bcoin
$ node browser/server.js 80 # Start up a simple webserver and websocket->tcp bridge

You should see something like this: http://i.imgur.com/0pWySyZ.png

CLI Usage

$ BCOIN_NETWORK=segnet4 node bin/node
# View the genesis block
$ node bin/bcoin-cli block 0
# View primary wallet
$ node bin/bcoin-cli wallet primary
# Send a tx
$ node bin/bcoin-cli send [address] 0.01
# View the mempool
$ node bin/bcoin-cli mempool

TX creation

TODO

Scripting

TODO

Wallet usage

TODO

Accessing the mempool

TODO

HTTP server/client

TODO

LICENSE

This software is licensed under the MIT License.

Copyright Fedor Indutny, 2014-2016.

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.