@ledgerhq/psbtv2

Partially Signed Bitcoin Transaction version 2 (PSBT v2) implementation following BIP370 and BIP174.

Overview

This package provides a TypeScript implementation of PSBT v2, which is a data structure that carries all relevant information about a Bitcoin transaction through all stages of the signing process - from constructing an unsigned transaction to extracting the final serialized transaction ready for broadcast.

Features

• Full PSBT v2 support (BIP370)
• Backward compatible with PSBT v0 (BIP174)
• Support for various address types:
  • P2PKH (Legacy)
  • P2WPKH-in-P2SH (Nested SegWit)
  • P2WPKH (Native SegWit)
  • P2TR (Taproot key path spending)

Usage

import { PsbtV2 } from "@ledgerhq/psbtv2";

// Create a new PSBT
const psbt = new PsbtV2();

// Deserialize from buffer
psbt.deserialize(psbtBuffer);

// Convert from PSBT v0 to v2
const psbtV0Buffer = Buffer.from("cHNidP8BAH...", "base64");
const psbtV2 = PsbtV2.fromV0(psbtV0Buffer);

// Allow transaction version 1 (version 2 is recommended per BIP68)
const psbtV2WithV1 = PsbtV2.fromV0(psbtV0Buffer, true);

// Access global fields
const version = psbt.getGlobalTxVersion();
const inputCount = psbt.getGlobalInputCount();
const outputCount = psbt.getGlobalOutputCount();

// Access input fields
const previousTxid = psbt.getInputPreviousTxid(0);
const outputIndex = psbt.getInputOutputIndex(0);

// Access output fields
const amount = psbt.getOutputAmount(0);
const script = psbt.getOutputScript(0);

// Serialize back to buffer
const serialized = psbt.serialize();

API

Global Fields

• Transaction version
• Fallback locktime
• Input count
• Output count
• TX modifiable flags
• PSBT version

Input Fields

• Non-witness UTXO
• Witness UTXO
• Partial signatures
• Sighash type
• Redeem script
• BIP32 derivation paths
• Final scriptsig
• Final scriptwitness
• Previous transaction ID
• Output index
• Sequence
• Taproot key signatures
• Taproot BIP32 derivation

Output Fields

• Redeem script
• BIP32 derivation paths
• Amount
• Script pubkey
• Taproot BIP32 derivation

License

Apache-2.0