Bitcoin: Getting error for transferring BTC using node js code, getting error “No inputs were signed”

Error Handling in Bitcoin Node.js Code: “No Inputs Were Signed”

As a developer working with Bitcoin, you’ve likely encountered the infamous error “No inputs were signed.” This issue can be frustrating, especially when building a system that requires transferring funds from one user’s wallet to another. In this article, we’ll delve into why this error occurs and provide guidance on how to resolve it using Node.js.

Understanding the Error

When a request is made to transfer Bitcoin (BTC) in your code, the bitcoinjs-rs library (a popular choice for building Bitcoin-based applications) attempts to create a new transaction. However, if the recipient’s wallet signature has not been signed correctly, the bitcoinjs-rs library will throw an error.

The “No inputs were signed” Error

This error occurs when the sender and receiver wallets do not have matching private keys or their signatures are invalid. The bitcoinjs-rs library expects both parties to provide a valid signature for each input in the transaction (i.e., the UTXOs being transferred).

When you try to create a new transaction with no inputs signed, the library throws an error stating that “No inputs were signed.”

Node.js Code Example

Let’s take a closer look at how your specific Node.js code might be causing this issue:

const bitcoin = require('bitcoinjs-rs');


// Load the wallet (UTXO) from disk

const utxos = loadWallet();


// Create a new transaction with no signed inputs

const tx = {

  sender: 'Spendable', // sender's address

  receiver: 'Spendable', // recipient's address

};


tx.inputs = [

  bitcoin.TransactionInput.new({

    address: 'Spendable',

    scriptSig: [bitcoin.SigType.HMAC, '0x1234567890abcdef'],

    scriptPubKey: [bitcoin.ScriptPubKey.new([bitcoin.ScriptPubKey.ASSIGN_SCRIPT pubkey, '0x1234567890abcdef'])],

  }),

];


// Sign the transaction inputs

tx.inputs.forEach((input) => {

  bitcoin.signTransaction(input);

});


// Attempt to create a new transaction with no signed inputs

const result = bitcoin.createTransaction(tx);

Solution

To resolve this issue, you need to ensure that both parties provide a valid signature for each input in the transaction. Here are some steps to follow:

• Load and verify UTXOs: Load the wallet UTXO from disk and verify their validity by checking their balance and ownership.

• Sign inputs

  

  : Use bitcoin.signTransaction() to sign each input with the sender’s private key. You can use a library like BitcoinJS-Wallet-Node or create your own implementation for this step.

• Create a new transaction: Create a new transaction using bitcoin.createTransaction(), passing in the signed inputs.

Here’s an updated example code snippet:

“javascript

const bitcoin = require('bitcoinjs-rs');

// Load and verify UTXOs

const utxos = loadWallet();

utxos.forEach((txo) => {

if (!bitcoin.verifyTxHash(txo.hash, txo.outpoint)) {

console.error(Invalid transaction hash: ${txo.hash}`);

return;

}

});

// Sign inputs

const sender = bitcoin.createAddress(‘Expendable’);

const receiver = bitcoin.createAddress(‘Receivable’);

const senderSign = bitcoin.signTransaction({

sender,

inputs: utxos.map((txo) => {

return bitcoin.TransactionInput.new({

address: txo.address,

scriptSig: bitcoin.SigType.HMAC, // Sign with the sender’s private key

scriptPubKey: bitcoin.ScriptPubKey.new([bitcoin.ScriptPubKey.ASSIGN_SCRIPT.pubkey, ‘0x1234567890abcdef’])],

});

}),

});

// Create a new transaction

const result = bitcoin.createTransaction({

inputs: utxos.map((txo) => {

return bitcoin.TransactionInput.new({

address: txo.address,

scriptSig: bitcoin.SigType.HMAC, // Sign with the sender’s private key

scriptPubKey: bitcoin.ScriptPubKey.new([bitcoin.ScriptPubKey.ASSIGN_SCRIPT.