@xchainjs/xchain-utxo

Modules

• client - Abstract base client for UTXO-based chains (Bitcoin, Litecoin, Dash, Dogecoin, Bitcoin Cash, etc.)
• utxo-selector - UTXO coin selection helpers
• strategies - Coin selection strategies (branch-and-bound, accumulative, largest-first, small-first, single-random-draw)
• validators - Transaction validation utilities
• errors - UTXO-specific error types
• coininfo / toBitcoinJS - Network parameter helpers for bitcoinjs-lib compatible coins

Installation

yarn add @xchainjs/xchain-utxo

Following peer dependencies have to be installed into your project. These are not included in @xchainjs/xchain-utxo.

yarn add @xchainjs/xchain-client @xchainjs/xchain-util @xchainjs/xchain-utxo-providers

Overview

This package provides the shared abstract Client used by UTXO chain packages in XChainJS. Chain-specific packages (for example @xchainjs/xchain-bitcoin or @xchainjs/xchain-dash) extend this base class and supply network constants, address formats, transaction building, and data providers.

Typical responsibilities of the base UTXO client:

• Explorer URL helpers
• Balance and UTXO fetching via pluggable UtxoOnlineDataProviders
• Transaction history and fee estimation wiring
• UTXO selection strategies for building inputs
• Shared types (UTXO, UtxoClientParams, PreparedTx, etc.)

You generally do not instantiate this package directly in application code. Use a concrete chain client instead:

import { Client, defaultBTCParams } from '@xchainjs/xchain-bitcoin'
// or
import { Client, defaultDashParams } from '@xchainjs/xchain-dash'

Usage (library / package authors)

When implementing a new UTXO chain client, extend the abstract Client and provide chain-specific logic:

import { Client as UTXOClient, UtxoClientParams } from '@xchainjs/xchain-utxo'
import { Network } from '@xchainjs/xchain-client'

class Client extends UTXOClient {
  constructor(params: UtxoClientParams) {
    super('MYCHAIN', params)
  }

  // Implement abstract methods: address derivation, tx building, signing, etc.
}

Coin selection strategies

import {
  UtxoSelector,
  // strategies are re-exported from the package
} from '@xchainjs/xchain-utxo'

Strategies can be used when preparing transactions to control how inputs are chosen (fee efficiency, privacy, consolidating small UTXOs, etc.).

Related packages

| Package | Role | | ------- | ---- | | @xchainjs/xchain-utxo-providers | Online data providers (BlockCypher, Sochain, BitGo, Haskoin, etc.) | | @xchainjs/xchain-client | Base XChain client interface | | @xchainjs/xchain-bitcoin | Example concrete UTXO client |

Documentation

More information about XChainJS can be found on documentation