Bitcoin3

Manage Bitcoin utxo

Install

npm install bitcoin3

Getting started

Create a bitcoin3 instance

const Bitcoin3 = require("bitcoin3")
const btc3     = new Bitcoin3("testnet")

//OPTIONAL: default blockcypher API
btc3.setProvider("blockcypher")

Get the balance

// Get balance of address
btc3.getBalance("2N8hwP1WmJrFF5QWABn38y63uYLhnJYJYTF").then(console.log)

Unlock the privatekey

//set the privatekey for signing
btc3.privateKeyToAccount("<privateKey>")

//Now the default account has been set
console.log(btc3.defaultAccount)

Send a transaction to a Bitcoin address

//Send the actual transaction to an address with the amount of satoshi comprhensive of actual value + fee
btc3.sendTransaction(addressTo, 20000).then(console.log).catch(console.log)

Bitcoin3 JavaScript API

All getters returns a Promise

Index

Setters

• setProvider()
• setNetwork()
• privateKeyToAccount()

Getters

• getBalance()
• getUtxo()
• estimateFee()

Utils

• isValidAddress()
• sendTransaction()
• createMultisig()

API

btc3.setProvider

Parameters

1. String - The blockexplorer API provider. Only blockcypher supported

Returns

none

Example

btc3.setProvider("blockcypher")

btc3.setNetwork

Parameters

1. String - The Bitcoin blockchain to work against. One of testnet and mainnet

Returns

none

Example

btc3.setNetwork("testnet")

btc3.privateKeyToAccount

Parameters

1. String - The WIF encoded private key. Mandatory for using sendTransaction

Returns

none

Example

btc3.privateKeyToAccount("e331b6d69882b4cb4ea581d88e0b604039a3de5967688d3dcffdd2270c0fd109")

btc3.getBalance

Parameters

1. String - The base58 Bitcoin address to watch the balance for.

Returns

• Promise:String|String - Returns the balance in satoshis or catch the error

Example

btc3.getBalance("2N8hwP1WmJrFF5QWABn38y63uYLhnJYJYTF")
  .then( satoshis => console.log('The balance is ' + satoshis))
  .catch( reason => console.log(reason))

//The balance is 1500000

btc3.getUtxo

Parameters

1. String - The base58 Bitcoin address to get the utxos of.

Returns

• Promise:Array|String - Returns the array of utxos per address in the standard format {txid, vout, satoshis, confirmations}

Example

btc3.getUtxo("2N8hwP1WmJrFF5QWABn38y63uYLhnJYJYTF")
  .then( utxos => console.log(utxos))
  .catch( reason => console.log(reason))

//[...]

btc3.estimateFee

Parameters

none

Returns

• Promise:String|String - Returns the amount in satoshi for the fastest fee

Example

btc3.estimateFee()
  .then( fastestFee => console.log(fastestFee))
  .catch( reason => console.log(reason))

//20000

btc3.isValidAddress

Parameters

1. String - The Bitcoin address to validate

Returns

• bool - Returns true if it is a valid base58 address

Example

const isValid = btc3.isValidAddress("000")
console.log(isValid)
//false

btc3.sendTransaction

Parameters

1. String - The Bitcoin address to sent sathosis
2. Number - The integer value of satoshis to be sent

Returns

• Promise:Object|String - Return the transaction object receipt

Example

const dest = "2N8hwP1WmJrFF5QWABn38y63uYLhnJYJYTF"
const amount = 15000000

btc3.sendTransaction(dest, amount)
.then(console.log)

// {...} 

btc3.createMultisig

Parameters

1. Array - Array of public keys in hex format
2. m - treshold needed for sign a valid transaction

Returns

• String - Return a m-of-n P2SH Multisig Address

Example

const keys = [
      '032b4c06c06c3ec0b7fa29519dfa5aae193ee2cc35ca127f29f14ec605d62fb63d',
      '0216c92abe433106491bdeb4a261226f20f5a4ac86220cc6e37655aac6bf3c1f2a',
      '039e05da8b8ea4f9868ecebb25998c7701542986233f4401799551fbecf316b18f'
]
const m = 2

const address = btc3.createMultisig(keys, 2)
console.log(address)
// testnet: 2N2VHjejHUCbJSRnoVyoesXMDsaiUey5ptp
//mainnet 3Aw5fuoFrk5xEeAFprBnFaMxfEWJp6vqNX