BitcoinKit-iOS

Bitcoin and BitcoinCash(ABC) SPV wallet toolkit for Swift. This is a full implementation of SPV node including wallet creation/restore, syncronzation with network, send/receive transactions, and more.

Features

• Full SPV implementation for fast mobile performance
• Send/Receive Legacy transactions (P2PKH, P2PK, P2SH)
• Send/Receive Segwit transactions (P2WPKH)
• Send/Receive Segwit transactions compatible with legacy wallets (P2WPKH-SH)
• Fee calculation depending on wether sender pays the fee or receiver
• Encoding/Decoding of base58, bech32, cashaddr addresses
• BIP32 hierarchical deterministic wallets implementation.
• BIP39 mnemonic code for generating deterministic keys.
• BIP44 multi-account hierarchy for deterministic wallets.
• BIP21 URI schemes, which include payment address, amount, label and other params
• Real-time fee rates

Usage

Initialization

BitcoinKit requires you to provide mnemonic phrase when it is initialized:

let words = ["word1", ... , "word12"]

Bitcoin

let bitcoinKit = BitcoinKit(withWords: words, coin: .bitcoin(network: .testNet), minLogLevel: .verbose)

Bitcoin Cash

let bitcoinCashKit = BitcoinKit(withWords: words, coin: .bitcoinCash(network: .testNet), minLogLevel: .verbose)

Both networks can be configured to work in mainNet or testNet.

Additional parameters:

• confirmationsThreshold: Minimum number of confirmations required for an unspent output in incoming transaction to be spent (default: 6)
• minLogLevel: Can be configured for debug purposes if required.

Starting and Stopping

BitcoinKit requires to be started with start command, but does not need to be stopped. It will be in synced state as long as it is possible:

try bitcoinKit.start()

Clearing data from device

BitcoinKit uses internal database for storing data fetched from blockchain. clear command can be used to stop and clean all stored data:

try bitcoinKit.clear()

Getting wallet data

BitcoinKit holds all kinds of data obtained from and needed for working with blockchain network

Current Balance

Balance is provided in Satoshi:

bitcoinKit.balance

// 2937096768

Last Block Info

Last block info contains headerHash, height and timestamp that can be used for displaying sync info to user:

bitcoinKit.lastBlockInfo 

// ▿ Optional<BlockInfo>
//  ▿ some : BlockInfo
//    - headerHash : //"00000000000041ae2164b486398415cca902a41214cad72291ee04b212bed4c4"
//    - height : 1446751
//    ▿ timestamp : Optional<Int>
//      - some : 1544097931

Receive Address

Get an address which you can receive coins to. Receive address is changed each time after you actually get a transaction in which you receive coins to that address

bitcoinKit.receiveAddress

// "mgv1KTzGZby57K5EngZVaPdPtphPmEWjiS"

Transactions

You can get all your transactions as follows:

bitcoinKit.transactions

// ▿ 2 elements
//   ▿ 0 : TransactionInfo
//     - transactionHash : "0f83c9b330f936dc4a2458b7d3bb06dce6647a521bf6d98f9c9d3cdd5f6d2a73"
//     ▿ from : 2 elements
//       ▿ 0 : TransactionAddressInfo
//         - address : "mft8jpnf3XwwqhaYSYMSXePFN85mGU4oBd"
//         - mine : true
//       ▿ 1 : TransactionAddressInfo
//         - address : "mnNS5LEQDnYC2xqT12MnQmcuSvhfpem8gt"
//         - mine : true
//     ▿ to : 2 elements
//       ▿ 0 : TransactionAddressInfo
//         - address : "n43efNftHQ1cXYMZK4Dc53wgR6XgzZHGjs"
//         - mine : false
//       ▿ 1 : TransactionAddressInfo
//         - address : "mrjQyzbX9SiJxRC2mQhT4LvxFEmt9KEeRY"
//         - mine : true
//     - amount : -800378
//     ▿ blockHeight : Optional<Int>
//       - some : 1446602
//    ▿ timestamp : Optional<Int>
//       - some : 1543995972
//   ▿ 1 : TransactionInfo
//  ...

Creating new transaction

In order to create new transaction, call send(to: String, value: Int) method on BitcoinKit

try bitcoinKit.send(to: "mrjQyzbX9SiJxRC2mQhT4LvxFEmt9KEeRY", value: 1000000)

This first validates a given address and amount, creates new transaction, then sends it over the peers network. If there's any error with given address/amount or network, it raises an exception.

Validating transaction before send

One can validate address and fee by using following methods:

try bitcoinKit.validate(address: "mrjQyzbX9SiJxRC2mQhT4LvxFEmt9KEeRY")
try bitcoinKit.fee(for: 1000000, toAddress: "mrjQyzbX9SiJxRC2mQhT4LvxFEmt9KEeRY", senderPay: true)

senderPay parameter defines who pays the fee

Parsing BIP21 URI

You can use parse method to parse a BIP21 URI:

bitcoinKit.parse(paymentAddress: "bitcoin:175tWpb8K1S7NmH4Zx6rewF9WQrcZv245W?amount=50&label=Luke-Jr&message=Donation%20for%20project%20xyz")

// ▿ BitcoinPaymentData
//   - address : "175tWpb8K1S7NmH4Zx6rewF9WQrcZv245W"
//   - version : nil
//   ▿ amount : Optional<Double>
//     - some : 50.0
//   ▿ label : Optional<String>
//     - some : "Luke-Jr"
//   ▿ message : Optional<String>
//     - some : "Donation for project xyz"
//   - parameters : nil

Subscribing to BitcoinKit data

BitcoinKit provides with data like transactions, blocks, balance, kits state in real-time. BitcoinKitDelegate protocol must be implemented and set to BitcoinKit instance to receive that data.

class Manager {

	init(words: [String]) {
		bitcoinKit = BitcoinKit(withWords: words, coin: .bitcoin(network: .mainNet)
        bitcoinKit.delegate = self
    }

}

extension Manager: BitcoinKitDelegate {

    public func transactionsUpdated(bitcoinKit: BitcoinKit, inserted: [TransactionInfo], updated: [TransactionInfo]) {
		// do something with transactions
    }

public func transactionsDeleted(hashes: [String]) {
    // do something with transactions
    }


    public func balanceUpdated(bitcoinKit: BitcoinKit, balance: Int) {
		// do something with balance
    }

    public func lastBlockInfoUpdated(bitcoinKit: BitcoinKit, lastBlockInfo: BlockInfo) {
		// do something with lastBlockInfo
    }

    public func kitStateUpdated(state: BitcoinKit.KitState) {
		// BitcoinKit.KitState can be one of 3 following states:
		// .synced
		// .syncing(progress: Double)
		// .notSynced
		// 
		// These states can be used to implement progress bar, etc
    }

}

Listener events are run in a dedicated background thread. It can be switched to main thread by setting the delegateQueue property to DispatchQueue.main

bitcoinKit.delegateQueue = DispatchQueue.main

Prerequisites

• Xcode 10.0+
• Swift 4.1+
• iOS 11+

Installation

CocoaPods

CocoaPods is a dependency manager for Cocoa projects. You can install it with the following command:

$ gem install cocoapods

CocoaPods 1.5.0+ is required to build BitcoinKit.

To integrate HSBitcoinKit into your Xcode project using CocoaPods, specify it in your Podfile:

source 'https://github.com/CocoaPods/Specs.git'
platform :ios, '10.0'
use_frameworks!

target '<Your Target Name>' do
	pod 'HSBitcoinKit'
end

Then, run the following command:

$ pod install

Example Project

All features of the library are used in example project. It can be referred as a starting point for usage of the library.

• Example Project

Dependencies

• HSHDWalletKit - HD Wallet related features, mnemonic phrase geneartion.
• HSCryptoKit - Crypto functions required for working with blockchain.

License

The HSBitcoinKit toolkit is open source and available under the terms of the MIT License.