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    bitcore-coinselect

    0.0.1 • Public • Published

    coinselect

    TRAVIS NPM

    js-standard-style

    An unspent transaction output (UTXO) selection module for bitcoin.

    This was built for bitcoin-lib specifically. However, as the original version of coinselect uses value for bitcoins, while most block explorers use amount for them, the module must have been annoying, so this could be the exact solution for you!

    Instllation

    npm install bitcore-coinselect --save
    

    WARNING: Amount units are in satoshis, not Bitcoin.

    Algorithms

    Module Algorithm Re-orders UTXOs?
    require('coinselect') Blackjack, with Accumulative fallback By Descending Amount
    require('coinselect/accumulative') Accumulative - accumulates inputs until the target amount (+fees) is reached, skipping detrimental inputs -
    require('coinselect/blackjack') Blackjack - accumulates inputs until the target amount (+fees) is matched, does not accumulate inputs that go over the target amount (within a threshold) -
    require('coinselect/break') Break - breaks the input amouts into equal denominations of output (as provided) -
    require('coinselect/split') Split - splits the input amounts evenly between all outputs, any provided output with .amount remains unchanged -

    Note: Each algorithm will add a change output if the input - output - fee amount difference is over a dust threshold. This is calculated independently by utils.finalize, irrespective of the algorithm chosen, for the purposes of safety.

    Pro-tip: if you want to send-all inputs to an output address, coinselect/split with a partial output (.address defined, no .amount) can be used to send-all, while leaving an appropriate amount for the fee.

    Example

    let coinSelect = require('coinselect')
    let feeRate = 55 // satoshis per byte
    let utxos = [
      ...,
      {
        txId: '...',
        vout: 0,
        ...,
        amount: 10000
      }
    ]
    let targets = [
      ...,
      {
        address: '1EHNa6Q4Jz2uvNExL497mE43ikXhwF6kZm',
        amount: 5000
      }
    ]
     
    // ...
    let { inputs, outputs, fee } = coinSelect(utxos, targets, feeRate)
     
    // the accumulated fee is always returned for analysis
    console.log(fee)
     
    // .inputs and .outputs will be undefined if no solution was found
    if (!inputs || !outputs) return
     
    let txb = new bitcoin.TransactionBuilder()
     
    inputs.forEach(input => txb.addInput(input.txId, input.vout))
    outputs.forEach(output => {
      // watch out, outputs may have been added that you need to provide
      // an output address/script for
      if (!output.address) {
        output.address = wallet.getChangeAddress()
        wallet.nextChangeAddress()
      }
     
      txb.addOutput(output.address, output.amount)
    })

    License MIT

    Install

    npm i bitcore-coinselect

    DownloadsWeekly Downloads

    3

    Version

    0.0.1

    License

    MIT

    Unpacked Size

    12.2 kB

    Total Files

    9

    Last publish

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