btctx

txbuilder

Build and sign Bitcoin Taproot transactions.

Installation

npm install txbuilder

Usage

As a module

import { buildTx } from 'txbuilder';

const result = await buildTx({
  privateKey: '0123456789abcdef...', // 64-char hex
  publicKey: 'fedcba9876543210...',  // 64-char hex (x-only)
  txid: 'abc123...',                 // Input txid
  vout: 0,                           // Input index
  inputAmount: 100000,               // Input satoshis
  outputs: [
    { pubkey: 'dest123...', amount: 99000 }
  ]
});

console.log(result.hex);     // Raw transaction hex
console.log(result.txid);    // Transaction ID
console.log(result.address); // Sender's Taproot address

As CLI

# Single output
txbuilder <privateKey> <publicKey> <txid> <vout> <inputAmount> <destPubkey> <destAmount>

# Multiple outputs
txbuilder <privkey> <pubkey> <txid> 0 100000 <dest1> 49000 <dest2> 49000

# Show help
txbuilder --help

API

buildTx(options)

Build and sign a Taproot transaction.

Options:

• privateKey (string) - 64-char hex private key for signing
• publicKey (string) - 64-char hex public key (x-only)
• txid (string) - Input transaction ID
• vout (number) - Input transaction output index (default: 0)
• inputAmount (number) - Input amount in satoshis
• outputs (array) - Array of {pubkey, amount} objects
• network (string) - Network: mainnet, testnet, regtest (default: mainnet)
• verify (boolean) - Verify signature after signing (default: true)

Returns: Promise<{hex, txid, address, txdata}>

getPublicKey(privateKey)

Derive x-only public key from private key.

getAddress(publicKey, network?)

Generate Taproot (P2TR) address from public key.

Dependencies

• @cmdcode/tapscript - Taproot transaction library

License

MIT