Bitcoin: How to create and sign a segwit transaction using any npm pacakge

Creating Segwit Transactions with Bitcore-Node: A Troubleshooting Guide

As a Node.js developer, you have probably encountered issues when using the bitcore-lib package to create and sign Bitcoin transactions. One of the most common challenges is trying to use the Segwit feature introduced in Bitcoin Core 26.1. In this article, we will explore how to overcome these limitations and successfully create Segwit transactions using the same NPM package.

Problem: Legacy Transactions

When you create legacy Bitcoin transactions with bitcore-lib, it seems that they do not support Segwit by default. This is because the package relies on the legacy Bitcoin Core protocol, which does not natively support Segwit. However, some npm packages have been created to bridge this gap.

Solution: Using bitcore-segwit

You can use the bitcore-segwit package (available at [ to create and sign Segwit transactions using any npm package that supports it. This package provides an easy way to work with Segwit-compatible bitcoin nodes and wallets.

Detailed Guide

Here is a step-by-step guide on how to create and sign Segwit transactions using bitcore-lib and bitcore-segwit:

• Install the required packages: Run the following command in your terminal:

npm install bitcore libseaweed

• Create a new transaction: Create a new transaction using the newTransaction method provided by libseaweed:

const { Transaction } = require('libseaweed');
const bitcoreLib = require('./bitcore-lib');
// Create a new wallet (e.g. from a private key)
leave wallet;
try {
const privateKey = 'your_private_key_here';
wallet = await bitcoreLib.createWallet(privateKey);
} catch (error) {
console.error(error);
}
// Create a new transaction
const tx = newTransaction(
wallet address,
[new BitcoindAddress('1.2.3.4:1234'), // sender address]
);
// Set the Segwit flag for the transaction
tx.setSegwits([
{ type: 'publicKey', privateKey: privateKey },
]);
// Sign the transaction with a new private key (or use an existing one)
const signature = wait bitcoreLib.signTransaction(tx, 'your_new_private_key_here');

In this example:

• We create a wallet using bitcore-lib and store it in the wallet variable.

• We will create a new transaction using libseaweed.

• We set the Segwit flag for the transaction by adding an object with two properties: type = 'publicKey' and privateKey = privateKey. This tells libseaweed to use your private key as the public key in the transaction.

• Finally, we will sign the transaction using the new private key.

Verify the transaction

To verify that the Segwit transaction was successfully created, you can use the following code:

const { Transaction } = require('libseaweed');
const bitcoreLib = require('./bitcore-lib');
// Create a new wallet (e.g. from a private key)
leave wallet;
try {
const privateKey = 'your_private_key_here';
wallet = await bitcoreLib.createWallet(privateKey);
} catch (error) {
console.error(error);
}
// Create a new transaction
const tx = newTransaction(
wallet address,
[new BitcoindAddress('1.2.3.4:1234'), // sender address]
);
// Set the Segwit flag for the transaction
tx.setSegwits([
{ type: 'publicKey', privateKey: privateKey },
]);
// Sign the transaction with a new private key (or use an existing one)
const signature = wait bitcoreLib.signTransaction(tx, 'your_new_private_key_here');
// Verify the transaction
const authenticationTx = new Transaction(
wallet address,
TX.hash,
);
wait for verificationTx.verify(signature);

If the transaction is successfully verified, you should see a message that the transaction has been confirmed.

Short Futures Premium