transaction charges – Switch all funds to a different pockets with node.js

Concerning first query,

No, you do not have to run your individual node. What I do know is blockstream esplora offers public API with documentation you may work with.

Concerning second query,

It is determined by what sort of segwit deal with(p2wpkh, p2wsh, p2tr) it’s, however I assume what you wish to spend can be the most typical segwit transaction, which is p2wpkh(single signature with public key).

For p2wpkh segwit spend, you may refer beneath code working for nodejs, which you’ll find right here, too.

import * as bitcoin from 'bitcoin-sdk-js';

const privkey =
  'e6c58327b4bf1314296bba7adb66f94c36ea5611ac07830c229aa7ee6f9caac3';
const toAddress="tb1qmjqyknun9umlwlle5nuy8jz9ms7v85cp7k2nfe";
const toValue = 300000; // unit is satoshi
const txHash="8bcd197873dbff5cc67cb3e0b1cbbdf097c7af94b0e9365adecb424e408294bf";
const inputValue = 310981; // price is enter worth - whole worth

const tx = new bitcoin.Transaction();

await tx.addInput({
  txHash: txHash,
  index: n, // it ought to be vout of utxo, index of utxo in transation
  worth: inputValue,
});
await tx.addOutput({
  deal with: toAddress,
  worth: toValue,
});
await tx.signInput(privkey, 0);

const txHex = await tx.getSignedHex();

For different kind of segwit deal with, it actually varies on unlocking script, so there’s not likely a technique answer for it.