micro-btc-signer

Create, sign & decode BTC transactions with minimum deps.

✍️ Create transactions, inputs, outputs, sign them
📡 No network code: simplified audits and offline usage
🎻 Classic & SegWit: P2PK, P2PKH, P2WPKH, P2SH, P2WSH, P2MS
🧪 Schnorr & Taproot BIP340/BIP341: P2TR, P2TR-NS, P2TR-MS
📨 BIP174 PSBT
👥 Multisig support
🪶 ~2.6K lines

The library is new and has not been audited or battle-tested, use at your own risk. Initial development has been funded by Ryan Shea. Check out the demo & its github.

Check out all web3 utility libraries: micro-eth-signer, micro-btc-signer, micro-sol-signer, micro-web3, tx-tor-broadcaster

Usage

General Usage

npm install micro-btc-signer

import * as btc from 'micro-btc-signer';

Payments

BTC has several UTXO types:

P2PK: Legacy, from 2010
P2PKH, P2SH, P2MS: Classic
P2WPKH, P2WSH: classic, SegWit
P2TR: Taproot, recommended

For test examples, the usage is as following:

npm install micro-btc-signer @scure/base assert

import * as btc from 'micro-btc-signer';
import { hex } from '@scure/base';
import { deepStrictEqual, throws } from 'assert';

P2PK (Pay To Public Key)

Old script, doesn't have address at all. Should be wrapped in P2SH/P2WSH/P2SH-P2WSH.

const uncompressed = hex.decode(
  '04ad90e5b6bc86b3ec7fac2c5fbda7423fc8ef0d58df594c773fa05e2c281b2bfe877677c668bd13603944e34f4818ee03cadd81a88542b8b4d5431264180e2c28'
);

deepStrictEqual(btc.p2pk(uncompressed), {
  type: 'pk',
  script: hex.decode(
    '4104ad90e5b6bc86b3ec7fac2c5fbda7423fc8ef0d58df594c773fa05e2c281b2bfe877677c668bd13603944e34f4818ee03cadd81a88542b8b4d5431264180e2c28ac'
  ),
});

P2PKH (Public Key Hash)

Classic address (pre-SegWit)

const PubKey = hex.decode('030000000000000000000000000000000000000000000000000000000000000001');
deepStrictEqual(btc.p2pkh(PubKey), {
  type: 'pkh',
  address: '134D6gYy8DsR5m4416BnmgASuMBqKvogQh',
  script: hex.decode('76a914168b992bcfc44050310b3a94bd0771136d0b28d188ac'),
});
// P2SH-P2PKH
deepStrictEqual(btc.p2sh(btc.p2pkh(PubKey)), {
  type: 'sh',
  address: '3EPhLJ1FuR2noj6qrTs4YvepCvB6sbShoV',
  script: hex.decode('a9148b530b962725af3bb7c818f197c619db3f71495087'),
  redeemScript: hex.decode('76a914168b992bcfc44050310b3a94bd0771136d0b28d188ac'),
});
// P2WSH-P2PKH
deepStrictEqual(btc.p2wsh(btc.p2pkh(PubKey)), {
  type: 'wsh',
  address: 'bc1qhxtthndg70cthfasy8y4qlk9h7r3006azn9md0fad5dg9hh76nkqaufnuz',
  script: hex.decode('0020b996bbcda8f3f0bba7b021c9507ec5bf8717bf5d14cbb6bd3d6d1a82defed4ec'),
  witnessScript: hex.decode('76a914168b992bcfc44050310b3a94bd0771136d0b28d188ac'),
});
// P2SH-P2WSH-P2PKH
deepStrictEqual(btc.p2sh(btc.p2wsh(btc.p2pkh(PubKey))), {
  type: 'sh',
  address: '3EHxWHyLv5Seu5Cd6D1cH56jLKxSi3ps8C',
  script: hex.decode('a9148a3d36fb710a9c7cae06cfcdf39792ff5773e8f187'),
  redeemScript: hex.decode('0020b996bbcda8f3f0bba7b021c9507ec5bf8717bf5d14cbb6bd3d6d1a82defed4ec'),
  witnessScript: hex.decode('76a914168b992bcfc44050310b3a94bd0771136d0b28d188ac'),
});

P2WPKH (Witness Public Key Hash)

Same as P2PKH, but for SegWit V0. Basic bech32 address. Cannot be wrapped in P2WSH.

const PubKey = hex.decode('030000000000000000000000000000000000000000000000000000000000000001');
deepStrictEqual(btc.p2wpkh(PubKey), {
  type: 'wpkh',
  address: 'bc1qz69ej270c3q9qvgt822t6pm3zdksk2x35j2jlm',
  script: hex.decode('0014168b992bcfc44050310b3a94bd0771136d0b28d1'),
});
// P2SH-P2WPKH
deepStrictEqual(btc.p2sh(btc.p2wpkh(PubKey)), {
  type: 'sh',
  address: '3BCuRViGCTXmQjyJ9zjeRUYrdZTUa38zjC',
  script: hex.decode('a91468602f2db7b7d7cdcd2639ab6bf7f5bfe828e53f87'),
  redeemScript: hex.decode('0014168b992bcfc44050310b3a94bd0771136d0b28d1'),
});

P2SH (Script Hash)

Classic (pre-SegWit) script address. Useful for multisig and other smart-contracts. Takes full output of other payments, not just script.

NOTE: redeemScript should be added to transaction input in order to spend.

const PubKey = hex.decode('030000000000000000000000000000000000000000000000000000000000000001');
// Wrap P2PKH in P2SH
deepStrictEqual(btc.p2sh(btc.p2pkh(PubKey)), {
  type: 'sh',
  address: '3EPhLJ1FuR2noj6qrTs4YvepCvB6sbShoV',
  script: hex.decode('a9148b530b962725af3bb7c818f197c619db3f71495087'),
  redeemScript: hex.decode('76a914168b992bcfc44050310b3a94bd0771136d0b28d188ac'),
});

P2WSH (Witness Script Hash)

Same as P2SH but for SegWit V0.

NOTE: witnessScript should be added to transaction input in order to spend.

const PubKey = hex.decode('030000000000000000000000000000000000000000000000000000000000000001');
deepStrictEqual(btc.p2wsh(btc.p2pkh(PubKey)), {
  type: 'wsh',
  address: 'bc1qhxtthndg70cthfasy8y4qlk9h7r3006azn9md0fad5dg9hh76nkqaufnuz',
  script: hex.decode('0020b996bbcda8f3f0bba7b021c9507ec5bf8717bf5d14cbb6bd3d6d1a82defed4ec'),
  witnessScript: hex.decode('76a914168b992bcfc44050310b3a94bd0771136d0b28d188ac'),
});

P2SH-P2WSH

Not really script type, but construction of P2WSH inside P2SH.

NOTE: both reedemScript and witnessScript should be added to transaction in order to spend.

const PubKey = hex.decode('030000000000000000000000000000000000000000000000000000000000000001');
deepStrictEqual(btc.p2sh(btc.p2wsh(btc.p2pkh(PubKey))), {
  type: 'sh',
  address: '3EHxWHyLv5Seu5Cd6D1cH56jLKxSi3ps8C',
  script: hex.decode('a9148a3d36fb710a9c7cae06cfcdf39792ff5773e8f187'),
  redeemScript: hex.decode('0020b996bbcda8f3f0bba7b021c9507ec5bf8717bf5d14cbb6bd3d6d1a82defed4ec'),
  witnessScript: hex.decode('76a914168b992bcfc44050310b3a94bd0771136d0b28d188ac'),
});

P2MS (classic multisig)

Classic (pre-taproot) M-of-N Multisig, doesn't have an address, should be wrapped in P2SH/P2WSH/P2SH-P2WSH.

NOTE: By default we don't accept duplicate public keys, to avoid creating wrong multisig by mistake. However there is a flag: allowSamePubkeys, in case you really need that. Valid use-case: 2-of-[A,A,B,C], can be signed by A or (B and C).

const PubKeys = [
  hex.decode('030000000000000000000000000000000000000000000000000000000000000001'),
  hex.decode('030000000000000000000000000000000000000000000000000000000000000002'),
  hex.decode('030000000000000000000000000000000000000000000000000000000000000003'),
];
// Multisig 2-of-3 wrapped in P2SH
deepStrictEqual(btc.p2sh(btc.p2ms(2, PubKeys)), {
  type: 'sh',
  address: '3G4AeQtzCLoDAyv2eb3UVTG5atfkyHtuRn',
  script: hex.decode('a9149d91c6de4eacde72a7cc86bff98d1915b3c7818f87'),
  redeemScript: hex.decode(
    '5221030000000000000000000000000000000000000000000000000000000000000001210300000000000000000000000000000000000000000000000000000000000000022103000000000000000000000000000000000000000000000000000000000000000353ae'
  ),
});
// Multisig 2-of-3 wrapped in P2WSH
deepStrictEqual(btc.p2wsh(btc.p2ms(2, PubKeys)), {
  type: 'wsh',
  address: 'bc1qwnhzkn8wcyyrnfyfcp7555urssu5dq0rmnvg70hg02z3nxgg4f0qljmr2h',
  script: hex.decode('002074ee2b4ceec10839a489c07d4a538384394681e3dcd88f3ee87a85199908aa5e'),
  witnessScript: hex.decode(
    '5221030000000000000000000000000000000000000000000000000000000000000001210300000000000000000000000000000000000000000000000000000000000000022103000000000000000000000000000000000000000000000000000000000000000353ae'
  ),
});
// Multisig 2-of-3 wrapped in P2SH-P2WSH
deepStrictEqual(btc.p2sh(btc.p2wsh(btc.p2ms(2, PubKeys))), {
  type: 'sh',
  address: '3HKWSo57kmcJZ3h43pXS3m5UESR4wXcWTd',
  script: hex.decode('a914ab70ab84b12b891364b4b2a14ca813cac308b24287'),
  redeemScript: hex.decode('002074ee2b4ceec10839a489c07d4a538384394681e3dcd88f3ee87a85199908aa5e'),
  witnessScript: hex.decode(
    '5221030000000000000000000000000000000000000000000000000000000000000001210300000000000000000000000000000000000000000000000000000000000000022103000000000000000000000000000000000000000000000000000000000000000353ae'
  ),
});
// Useful util: wraps P2MS in P2SH or P2WSH
deepStrictEqual(btc.p2sh(btc.p2ms(2, PubKeys)), btc.multisig(2, PubKeys));
deepStrictEqual(btc.p2wsh(btc.p2ms(2, PubKeys)), btc.multisig(2, PubKeys, undefined, true));
// Sorted multisig (BIP67)
deepStrictEqual(btc.p2sh(btc.p2ms(2, PubKeys)), btc.sortedMultisig(2, PubKeys));
deepStrictEqual(btc.p2wsh(btc.p2ms(2, PubKeys)), btc.sortedMultisig(2, PubKeys, true));

P2TR (Taproot)

TapRoot (SegWit V1) script which replaces both public key and script types from previous versions.

NOTE: it takes p2tr(PubKey?, ScriptTree?) and works as PubKey OR ScriptTree, which means if you use any spendable PubKey and ScriptTree of multi-sig, owner of private key for PubKey will be able to spend output. If PubKey is undefined we use static unspendable PubKey by default, which leaks information about script type. However, any dynamic unspendable keys will require complex interaction to sign multi-sig wallets, and there is no BIP/PSBT fields for that yet.

NOTE: tapInternalKey, tapMerkleRoot, tapLeafScript should be added to transaction input in order to spend.

const PubKey = hex.decode('0101010101010101010101010101010101010101010101010101010101010101');
// Key Path Spend (owned of private key for PubKey can spend)
deepStrictEqual(btc.p2tr(PubKey), {
  type: 'tr',
  address: 'bc1p7yu5dsly83jg5tkxcljsa30vnpdpl22wr6rty98t6x6p6ekz2gkqzf2t2s',
  script: hex.decode('5120f13946c3e43c648a2ec6c7e50ec5ec985a1fa94e1e86b214ebd1b41d66c2522c'),
  tweakedPubkey: hex.decode('f13946c3e43c648a2ec6c7e50ec5ec985a1fa94e1e86b214ebd1b41d66c2522c'),
  tapInternalKey: hex.decode('0101010101010101010101010101010101010101010101010101010101010101'),
  tapMerkleRoot: hex.decode(''),
});

const PubKey2 = hex.decode('0202020202020202020202020202020202020202020202020202020202020202');
const PubKey3 = hex.decode('1212121212121212121212121212121212121212121212121212121212121212');
// Nested P2TR, owner of private key for any of PubKeys can spend whole
// NOTE: by default P2TR expects binary tree, but btc.p2tr can build it if list of scripts passed.
// Also, you can include {weight: N} to scripts to create differently balanced tree.
deepStrictEqual(btc.p2tr(undefined, [btc.p2tr(PubKey), btc.p2tr(PubKey2), btc.p2tr(PubKey3)]), {
  type: 'tr',
  // weights for bitcoinjs-lib: [3,2,1]
  address: 'bc1p58hcmfcjaee0jwzlgluzw86paw0h7sqmw2c8yq8t4wleqlqdn3qqv3rxf0',
  script: hex.decode('5120a1ef8da712ee72f9385f47f8271f41eb9f7f401b72b07200ebabbf907c0d9c40'),
});
// If scriptsTree is already binary tree, it will be used as-is
deepStrictEqual(btc.p2tr(undefined, [btc.p2tr(PubKey2), [btc.p2tr(PubKey), btc.p2tr(PubKey3)]]), {
  type: 'tr',
  // default weights for bitcoinjs-lib
  address: 'bc1pepwhs2tvnn6uj9eqy8kqdwjk2n3r8wjkunqcmahvkn4r2uyvzsxqqae82s',
  script: hex.decode('5120c85d78296c9cf5c9172021ec06ba5654e233ba56e4c18df6ecb4ea35708c140c'),
});

P2TR-NS (Taproot multisig)

Taproot N-of-N multisig ([<PubKeys[0:n-1]> CHECKSIGVERIFY] <PubKeys[n-1]> CHECKSIG).

NOTE: First arg is M, if M!=PubKeys.length, it will create a multi-leaf M-of-N taproot script tree. This allows one to reveal only M PubKeys on spend, without any information about the others. This is fast for cases like 15-of-20, but extremely slow for cases like 5-of-20.

NOTE: By default we don't accept duplicate public keys, to avoid creating the wrong multisig by mistake. However there is a flag called allowSamePubkeys, in case you really need that. Valid use-case: 2-of-[A,A,B,C], can be signed by A or (B and C).

const PubKey = hex.decode('0101010101010101010101010101010101010101010101010101010101010101');
const PubKey2 = hex.decode('0202020202020202020202020202020202020202020202020202020202020202');
const PubKey3 = hex.decode('1212121212121212121212121212121212121212121212121212121212121212');

// Simple 3-of-3 multisig
// Creates a single script that requires all three pubkeys: [PubKey, PubKey2, PubKey3]
deepStrictEqual(btc.p2tr_ns(3, [PubKey, PubKey2, PubKey3]), [
  {
    type: 'tr_ns',
    script: hex.decode(
      '200101010101010101010101010101010101010101010101010101010101010101ad200202020202020202020202020202020202020202020202020202020202020202ad201212121212121212121212121212121212121212121212121212121212121212ac'
    ),
  },
]);
// Simple 2-of-3 multisig
// If M (pubkeys required) is less than N (# of pubkeys), then multiple scripts are created: [[PubKey, PubKey2], [PubKey, PubKey3], [PubKey2, PubKey3]]
deepStrictEqual(btc.p2tr(undefined, btc.p2tr_ns(2, [PubKey, PubKey2, PubKey3])), {
  type: 'tr',
  address: 'bc1pevfcmnkqqq09a4n0fs8c7mwlc6r4efqpvgyqpjvegllavgw235fq3kz7a0',
  script: hex.decode('5120cb138dcec0001e5ed66f4c0f8f6ddfc6875ca401620800c99947ffd621ca8d12'),
});

P2TR-MS (Taproot M-of-N multisig)

M-of-N single leaf TapRoot multisig (<PubKeys[0]> CHECKSIG [<PubKeys[1:n]> CHECKSIGADD] <M> NUMEQUAL)

NOTE: By default, we don't accept duplicate public keys in order to avoid creating the wrong multisig by mistake. However, there is a flag called allowSamePubkeys, in case you really need that. Valid use-case: 2-of-[A,A,B,C], can be signed by A or (B and C).

NOTE: experimental, use at your own risk.

const PubKey = hex.decode('0101010101010101010101010101010101010101010101010101010101010101');
const PubKey2 = hex.decode('0202020202020202020202020202020202020202020202020202020202020202');
const PubKey3 = hex.decode('1212121212121212121212121212121212121212121212121212121212121212');
// 2-of-3 TapRoot multisig
deepStrictEqual(btc.p2tr_ms(2, [PubKey, PubKey2, PubKey3]), {
  type: 'tr_ms',
  script: hex.decode(
    '200101010101010101010101010101010101010101010101010101010101010101ac200202020202020202020202020202020202020202020202020202020202020202ba201212121212121212121212121212121212121212121212121212121212121212ba529c'
  ),
});
// Creates a single script for [PubKey, PubKey2, PubKey3]
deepStrictEqual(btc.p2tr(undefined, btc.p2tr_ms(2, [PubKey, PubKey2, PubKey3])), {
  type: 'tr_ms',
  address: 'bc1p6m2xevckax9zucumnnyvu4xhxem66ugc5r2zlw2a20s0hxnutl8qfef23s',
  script: hex.decode('5120d6d46cb316e98a2e639b9cc8ce54d73677ad7118a0d42fb95d53e0fb9a7c5fce'),
});

P2TR-PK (Taproot single P2PK script)

This is a specific case of p2tr_ns(1, [pubkey]), which is the same as the BTC descriptor: tr($H,pk(PUBKEY))

const PubKey = hex.decode('0101010101010101010101010101010101010101010101010101010101010101');
// P2PK for taproot
deepStrictEqual(tr(btc.p2tr(undefined, [btc.p2tr_pk(PubKey)])), {
  type: 'tr',
  address: 'bc1pfj6w68w3v2f4pkzesc9tsqfvy5znw5qgydwa832v3v83vjn76kdsmr4360',
  script: hex.decode('51204cb4ed1dd1629350d859860ab8012c2505375008235dd3c54c8b0f164a7ed59b'),
});

Transaction

Encode/decode

NOTE: we support both PSBTv0 and draft PSBTv2 (there is no PSBTv1). If PSBTv2 transaction encoded into PSBTv1, all PSBTv2 fields will be stripped. NOTE: we strip 'unknown' keys inside PSBT, they needed for new version/features support, however any unsupported feature/new version can significantly break assumptions about code. If you have use-case where they needed, please open issue. For PSBTv2: tx_modifiable, taproot+bip32 is not supported yet.

// Decode
Transaction.fromRaw(raw: Bytes, opts: TxOpts = {}); // Raw tx
Transaction.fromPSBT(psbt: Bytes, opts: TxOpts = {}); // PSBT tx
// Encode
tx.unsignedTx; // Bytes of raw unsigned tx
tx.hex; // hex encoded signed raw tx
tx.toPSBT(ver = this.PSBTVersion); // PSBT

Inputs

We have txid (BE) instead of hash (LE) in transactions. We can support both, but txid is consistent across block explorers, while some explorers treat hash as txid - so hash is not consistent.

type TransactionInput = {
  txid?: Bytes,
  index?: number,
  nonWitnessUtxo?: <RawTransactionBytesOrHex>,
  witnessUtxo?: {script?: Bytes; amount: bigint},
  partialSig?: [Bytes, Bytes][]; // [PubKey, Signature]
  sighashType?: P.U32LE,
  redeemScript?: Bytes,
  witnessScript?: Bytes,
  bip32Derivation?: [Bytes, {fingerprint: number; path: number[]}]; // [PubKey, DeriviationPath]
  finalScriptSig?: Bytes,
  finalScriptWitness?: Bytes[],
  porCommitment?: Bytes,
  sequence?: number,
  requiredTimeLocktime?: number,
  requiredHeightLocktime?: number,
  tapKeySig?: Bytes,
  tapScriptSig?: [Bytes, Bytes][]; // [PubKeySchnorr, LeafHash]
  // [ControlBlock, ScriptWithVersion]
  tapLeafScript?: [{version: number; internalKey: Bytes; merklePath: Bytes[]}, Bytes];
  tapInternalKey?: Bytes,
  tapMerkleRoot?: Bytes,
};

tx.addInput(input: TransactionInput): number;
tx.updateInput(idx: number, input: TransactionInput);

// Input
tx.addInput({ txid: new Uint8Array(32), index: 0 });
deepStrictEqual(tx.inputs[0], {
  txid: new Uint8Array(32),
  index: 0,
  sequence: btc.DEFAULT_SEQUENCE,
});
// Update basic value
tx.updateInput(0, { index: 10 });
deepStrictEqual(tx.inputs[0], {
  txid: new Uint8Array(32),
  index: 10,
  sequence: btc.DEFAULT_SEQUENCE,
});
// Add value as hex
tx.addInput({
  txid: '0000000000000000000000000000000000000000000000000000000000000000',
  index: 0,
});
deepStrictEqual(tx.inputs[2], {
  txid: new Uint8Array(32),
  index: 0,
  sequence: btc.DEFAULT_SEQUENCE,
});
// Update key map
const pubKey = hex.decode('030000000000000000000000000000000000000000000000000000000000000001');
const bip1 = [pubKey, { fingerprint: 5, path: [1, 2, 3] }];
const pubKey2 = hex.decode('030000000000000000000000000000000000000000000000000000000000000002');
const bip2 = [pubKey2, { fingerprint: 6, path: [4, 5, 6] }];
const pubKey3 = hex.decode('030000000000000000000000000000000000000000000000000000000000000003');
const bip3 = [pubKey3, { fingerprint: 7, path: [7, 8, 9] }];
// Add K-V
tx.updateInput(0, { bip32Derivation: [bip1] });
deepStrictEqual(tx.inputs[0].bip32Derivation, [bip1]);
// Add another K-V
tx.updateInput(0, { bip32Derivation: [bip2] });
deepStrictEqual(tx.inputs[0].bip32Derivation, [bip1, bip2]);
// Delete K-V
tx.updateInput(0, { bip32Derivation: [[pubKey, undefined]] });
deepStrictEqual(tx.inputs[0].bip32Derivation, [bip2]);
// Second add of same k-v does nothing
tx.updateInput(0, { bip32Derivation: [bip2] });
deepStrictEqual(tx.inputs[0].bip32Derivation, [bip2]);
// Second add of k-v with different value breaks
throws(() => tx.updateInput(0, { bip32Derivation: [[pubKey2, bip1[1]]] }));
tx.updateInput(0, { bip32Derivation: [bip1, bip2, bip3] });
// Preserves order (re-ordered on PSBT encoding)
deepStrictEqual(tx.inputs[0].bip32Derivation, [bip2, bip1, bip3]);
// PSBT encoding re-order k-v
const tx2 = btc.Transaction.fromPSBT(tx.toPSBT());
deepStrictEqual(tx2.inputs[0].bip32Derivation, [bip1, bip2, bip3]);
// Remove field
tx.updateInput(0, { bip32Derivation: undefined });
deepStrictEqual(tx.inputs[0], {
  txid: new Uint8Array(32),
  index: 10,
  sequence: btc.DEFAULT_SEQUENCE,
});

Outputs

NOTE: amount in addOutputAddress handled as 'bitcoins' if string, and as satoshi if bigint. Why? BigInt usually comes from calculations/API, which is usually in satoshi. String is probably user input, so it is worth to handle conversion to satoshi's in that case.

type TransactionOutput = {
  script?: Bytes,
  amount?: bigint,
  redeemScript?: Bytes,
  witnessScript?: Bytes,
  bip32Derivation?: [Bytes, {fingerprint: number; path: number[]}]; // [PubKey, DeriviationPath]
  tapInternalKey?: Bytes,
};

tx.addOutput(o: TransactionOutput): number;
tx.updateOutput(idx: number, output: TransactionOutput);
tx.addOutputAddress(address: string, amount: string | bigint, network = NETWORK): number;

const compressed = hex.decode(
  '030000000000000000000000000000000000000000000000000000000000000001'
);
const script = btc.p2pkh(compressed).script;
tx.addOutput({ script, amount: 100n });
deepStrictEqual(tx.outputs[0], {
  script,
  amount: 100n,
});
// Update basic value
tx.updateOutput(0, { amount: 200n });
deepStrictEqual(tx.outputs[0], {
  script,
  amount: 200n,
});
// Add K-V
tx.updateOutput(0, { bip32Derivation: [bip1] });
deepStrictEqual(tx.outputs[0].bip32Derivation, [bip1]);
// Add another K-V
tx.updateOutput(0, { bip32Derivation: [bip2] });
deepStrictEqual(tx.outputs[0].bip32Derivation, [bip1, bip2]);
// Delete K-V
tx.updateOutput(0, { bip32Derivation: [[pubKey, undefined]] });
deepStrictEqual(tx.outputs[0].bip32Derivation, [bip2]);
// Second add of same k-v does nothing
tx.updateOutput(0, { bip32Derivation: [bip2] });
deepStrictEqual(tx.outputs[0].bip32Derivation, [bip2]);
// Second add of k-v with different value breaks
throws(() => tx.updateOutput(0, { bip32Derivation: [[pubKey2, bip1[1]]] }));
tx.updateOutput(0, { bip32Derivation: [bip1, bip2, bip3] });
// Preserves order (re-ordered on PSBT encoding)
deepStrictEqual(tx.outputs[0].bip32Derivation, [bip2, bip1, bip3]);
// PSBT encoding re-order k-v
const tx3 = btc.Transaction.fromPSBT(tx.toPSBT());
deepStrictEqual(tx3.outputs[0].bip32Derivation, [bip1, bip2, bip3]);
// Remove field
tx.updateOutput(0, { bip32Derivation: undefined });
deepStrictEqual(tx.outputs[0], {
  script,
  amount: 200n,
});

Basic transaction sign

const privKey = hex.decode('0101010101010101010101010101010101010101010101010101010101010101');
const txP2WPKH = new btc.Transaction();
for (const inp of TX_TEST_INPUTS) {
  txP2WPKH.addInput({
    txid: inp.txid,
    index: inp.index,
    witnessUtxo: {
      amount: inp.amount,
      script: btc.p2wpkh(secp256k1.getPublicKey(privKey, true)).script,
    },
  });
}
for (const [address, amount] of TX_TEST_OUTPUTS) tx32.addOutputAddress(address, amount);
deepStrictEqual(hex.encode(tx32.unsignedTx), RAW_TX_HEX);
txP2WPKH.sign(privKey);
txP2WPKH.finalize();
deepStrictEqual(txP2WPKH.id, 'cbb94443b19861df0824914fa654212facc071854e0df6f7388b482a6394526d');
deepStrictEqual(
  txP2WPKH.hex,
  '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'
);

BIP174 PSBT multi-sig example

const testnet = {
  wif: 0xef,
  bip32: {
    public: 0x043587cf,
    private: 0x04358394,
  },
};
// The private keys in the tests below are derived from the following master private key:
const epriv =
  'tprv8ZgxMBicQKsPd9TeAdPADNnSyH9SSUUbTVeFszDE23Ki6TBB5nCefAdHkK8Fm3qMQR6sHwA56zqRmKmxnHk37JkiFzvncDqoKmPWubu7hDF';
const hdkey = bip32.HDKey.fromExtendedKey(epriv, testnet.bip32);
// const seed = 'cUkG8i1RFfWGWy5ziR11zJ5V4U4W3viSFCfyJmZnvQaUsd1xuF3T';
const tx = new btc.Transaction(2);
// A creator creating a PSBT for a transaction which creates the following outputs:
tx.addOutput({ script: '0014d85c2b71d0060b09c9886aeb815e50991dda124d', amount: '1.49990000' });
tx.addOutput({ script: '001400aea9a2e5f0f876a588df5546e8742d1d87008f', amount: '1.00000000' });
// and spends the following inputs:
tx.addInput({
  txid: '75ddabb27b8845f5247975c8a5ba7c6f336c4570708ebe230caf6db5217ae858',
  index: 0,
});
tx.addInput({
  txid: '1dea7cd05979072a3578cab271c02244ea8a090bbb46aa680a65ecd027048d83',
  index: 1,
});
// must create this PSBT:
const psbt1 = tx.toPSBT();
// Given the above PSBT, an updater with only the following:
const tx2 = btc.Transaction.fromPSBT(psbt1);
tx2.updateInput(0, {
  nonWitnessUtxo:
    '0200000001aad73931018bd25f84ae400b68848be09db706eac2ac18298babee71ab656f8b0000000048473044022058f6fc7c6a33e1b31548d481c826c015bd30135aad42cd67790dab66d2ad243b02204a1ced2604c6735b6393e5b41691dd78b00f0c5942fb9f751856faa938157dba01feffffff0280f0fa020000000017a9140fb9463421696b82c833af241c78c17ddbde493487d0f20a270100000017a91429ca74f8a08f81999428185c97b5d852e4063f618765000000',
  redeemScript:
    '5221029583bf39ae0a609747ad199addd634fa6108559d6c5cd39b4c2183f1ab96e07f2102dab61ff49a14db6a7d02b0cd1fbb78fc4b18312b5b4e54dae4dba2fbfef536d752ae',
  bip32Derivation: [
    [
      '029583bf39ae0a609747ad199addd634fa6108559d6c5cd39b4c2183f1ab96e07f',
      { fingerprint: hdkey.fingerprint, path: btc.bip32Path("m/0'/0'/0'") },
    ],
    [
      '02dab61ff49a14db6a7d02b0cd1fbb78fc4b18312b5b4e54dae4dba2fbfef536d7',
      { fingerprint: hdkey.fingerprint, path: btc.bip32Path("m/0'/0'/1'") },
    ],
  ],
});
tx2.updateInput(1, {
  // use witness utxo ({script, amount})
  witnessUtxo: btc.RawTx.decode(
    hex.decode(
      '0200000000010158e87a21b56daf0c23be8e7070456c336f7cbaa5c8757924f545887bb2abdd7501000000171600145f275f436b09a8cc9a2eb2a2f528485c68a56323feffffff02d8231f1b0100000017a914aed962d6654f9a2b36608eb9d64d2b260db4f1118700c2eb0b0000000017a914b7f5faf40e3d40a5a459b1db3535f2b72fa921e88702483045022100a22edcc6e5bc511af4cc4ae0de0fcd75c7e04d8c1c3a8aa9d820ed4b967384ec02200642963597b9b1bc22c75e9f3e117284a962188bf5e8a74c895089046a20ad770121035509a48eb623e10aace8bfd0212fdb8a8e5af3c94b0b133b95e114cab89e4f7965000000'
    )
  ).outputs[1],
  redeemScript: '00208c2353173743b595dfb4a07b72ba8e42e3797da74e87fe7d9d7497e3b2028903',
  witnessScript:
    '522103089dc10c7ac6db54f91329af617333db388cead0c231f723379d1b99030b02dc21023add904f3d6dcf59ddb906b0dee23529b7ffb9ed50e5e86151926860221f0e7352ae',
  bip32Derivation: [
    [
      '03089dc10c7ac6db54f91329af617333db388cead0c231f723379d1b99030b02dc',
      { fingerprint: hdkey.fingerprint, path: btc.bip32Path("m/0'/0'/2'") },
    ],
    [
      '023add904f3d6dcf59ddb906b0dee23529b7ffb9ed50e5e86151926860221f0e73',
      { fingerprint: hdkey.fingerprint, path: btc.bip32Path("m/0'/0'/3'") },
    ],
  ],
});
tx2.updateOutput(0, {
  bip32Derivation: [
    [
      '03a9a4c37f5996d3aa25dbac6b570af0650394492942460b354753ed9eeca58771',
      { fingerprint: hdkey.fingerprint, path: btc.bip32Path("m/0'/0'/4'") },
    ],
  ],
});
tx2.updateOutput(1, {
  bip32Derivation: [
    [
      '027f6399757d2eff55a136ad02c684b1838b6556e5f1b6b34282a94b6b50051096',
      { fingerprint: hdkey.fingerprint, path: btc.bip32Path("m/0'/0'/5'") },
    ],
  ],
});
// Must create this PSBT:
const psbt2 = tx2.toPSBT();
// An updater which adds SIGHASH_ALL to the above PSBT must create this PSBT:
const tx3 = btc.Transaction.fromPSBT(psbt2);
for (let i = 0; i < tx3.inputs.length; i++)
  tx3.updateInput(i, { sighashType: btc.SignatureHash.ALL });
const psbt3 = tx3.toPSBT();
/*
  Given the above updated PSBT, a signer that supports SIGHASH_ALL for P2PKH and P2WPKH spends and uses RFC6979 for nonce generation and has the following keys:
  - cP53pDbR5WtAD8dYAW9hhTjuvvTVaEiQBdrz9XPrgLBeRFiyCbQr (m/0'/0'/0')
  - cR6SXDoyfQrcp4piaiHE97Rsgta9mNhGTen9XeonVgwsh4iSgw6d (m/0'/0'/2')
*/
// NOTE: we don't use HDKey, because it will everything because of bip32 derivation
const tx4 = btc.Transaction.fromPSBT(psbt3);
tx4.sign(btc.WIF(testnet).decode('cP53pDbR5WtAD8dYAW9hhTjuvvTVaEiQBdrz9XPrgLBeRFiyCbQr'));
tx4.sign(btc.WIF(testnet).decode('cR6SXDoyfQrcp4piaiHE97Rsgta9mNhGTen9XeonVgwsh4iSgw6d'));
// must create this PSBT:
const psbt4 = tx4.toPSBT();
// Given the above updated PSBT, a signer with the following keys:
// cT7J9YpCwY3AVRFSjN6ukeEeWY6mhpbJPxRaDaP5QTdygQRxP9Au (m/0'/0'/1')
// cNBc3SWUip9PPm1GjRoLEJT6T41iNzCYtD7qro84FMnM5zEqeJsE (m/0'/0'/3')
const tx5 = btc.Transaction.fromPSBT(psbt3);
tx5.sign(btc.WIF(testnet).decode('cT7J9YpCwY3AVRFSjN6ukeEeWY6mhpbJPxRaDaP5QTdygQRxP9Au'));
tx5.sign(btc.WIF(testnet).decode('cNBc3SWUip9PPm1GjRoLEJT6T41iNzCYtD7qro84FMnM5zEqeJsE'));
// must create this PSBT:
const psbt5 = tx5.toPSBT();
// Given both of the above PSBTs, a combiner must create this PSBT:
const psbt6 = btc.PSBTCombine([psbt4, psbt5]);
// Given the above PSBT, an input finalizer must create this PSBT:
const tx7 = btc.Transaction.fromPSBT(psbt6);
tx7.finalize();
const psbt7 = tx7.toPSBT();
// Given the above PSBT, a transaction extractor must create this Bitcoin transaction:
const tx8 = btc.Transaction.fromPSBT(psbt7);
deepStrictEqual(
  tx8.extract(),
  hex.decode(
    '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'
  )
);

Utils

getAddress

Returns common addresses from privateKey

const privKey = hex.decode('0101010101010101010101010101010101010101010101010101010101010101');
deepStrictEqual(btc.getAddress('pkh', privKey), '1C6Rc3w25VHud3dLDamutaqfKWqhrLRTaD'); // P2PKH (legacy address)
deepStrictEqual(btc.getAddress('wpkh', privKey), 'bc1q0xcqpzrky6eff2g52qdye53xkk9jxkvrh6yhyw'); // SegWit V0 address
deepStrictEqual(
  btc.getAddress('tr', priv),
  'bc1p33wm0auhr9kkahzd6l0kqj85af4cswn276hsxg6zpz85xe2r0y8syx4e5t'
); // TapRoot KeyPathSpend

WIF

Encoding/decoding of WIF privateKeys. Only compessed keys are supported for now.

const privKey = hex.decode('0101010101010101010101010101010101010101010101010101010101010101');
deepStrictEqual(btc.WIF().encode(privKey), 'KwFfNUhSDaASSAwtG7ssQM1uVX8RgX5GHWnnLfhfiQDigjioWXHH');
deepStrictEqual(
  hex.encode(btc.WIF().decode('KwFfNUhSDaASSAwtG7ssQM1uVX8RgX5GHWnnLfhfiQDigjioWXHH')),
  '0101010101010101010101010101010101010101010101010101010101010101'
);

Script

Encoding/decoding bitcoin scripts

deepStrictEqual(
  btc.Script.decode(
    hex.decode(
      '5221030000000000000000000000000000000000000000000000000000000000000001210300000000000000000000000000000000000000000000000000000000000000022103000000000000000000000000000000000000000000000000000000000000000353ae'
    )
  ).map((i) => (P.isBytes(i) ? hex.encode(i) : i)),
  [
    'OP_2',
    '030000000000000000000000000000000000000000000000000000000000000001',
    '030000000000000000000000000000000000000000000000000000000000000002',
    '030000000000000000000000000000000000000000000000000000000000000003',
    'OP_3',
    'CHECKMULTISIG',
  ]
);
deepStrictEqual(
  hex.encode(
    btc.Script.encode([
      'OP_2',
      hex.decode('030000000000000000000000000000000000000000000000000000000000000001'),
      hex.decode('030000000000000000000000000000000000000000000000000000000000000002'),
      hex.decode('030000000000000000000000000000000000000000000000000000000000000003'),
      'OP_3',
      'CHECKMULTISIG',
    ])
  ),
  '5221030000000000000000000000000000000000000000000000000000000000000001210300000000000000000000000000000000000000000000000000000000000000022103000000000000000000000000000000000000000000000000000000000000000353ae'
);

OutScript

Encoding/decoding of output scripts

deepStrictEqual(
  btc.OutScript.decode(
    hex.decode(
      '5221030000000000000000000000000000000000000000000000000000000000000001210300000000000000000000000000000000000000000000000000000000000000022103000000000000000000000000000000000000000000000000000000000000000353ae'
    )
  ),
  {
    type: 'ms',
    m: 2,
    pubkeys: [
      '030000000000000000000000000000000000000000000000000000000000000001',
      '030000000000000000000000000000000000000000000000000000000000000002',
      '030000000000000000000000000000000000000000000000000000000000000003',
    ].map(hex.decode),
  }
);
deepStrictEqual(
  hex.encode(
    btc.OutScript.encode({
      type: 'ms',
      m: 2,
      pubkeys: [
        '030000000000000000000000000000000000000000000000000000000000000001',
        '030000000000000000000000000000000000000000000000000000000000000002',
        '030000000000000000000000000000000000000000000000000000000000000003',
      ].map(hex.decode),
    })
  ),
  '5221030000000000000000000000000000000000000000000000000000000000000001210300000000000000000000000000000000000000000000000000000000000000022103000000000000000000000000000000000000000000000000000000000000000353ae'
);

License

MIT (c) Paul Miller (https://paulmillr.com), see LICENSE file.

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README.md

README.md

micro-btc-signer

Usage

General Usage

Table of Contents

Payments

P2PK (Pay To Public Key)

P2PKH (Public Key Hash)

P2WPKH (Witness Public Key Hash)

P2SH (Script Hash)

P2WSH (Witness Script Hash)

P2SH-P2WSH

P2MS (classic multisig)

P2TR (Taproot)

P2TR-NS (Taproot multisig)

P2TR-MS (Taproot M-of-N multisig)

P2TR-PK (Taproot single P2PK script)

Transaction

Encode/decode

Inputs

Outputs

Basic transaction sign

BIP174 PSBT multi-sig example

Utils

getAddress

WIF

Script

OutScript

License

Files

README.md

Latest commit

History

README.md

File metadata and controls

micro-btc-signer

Usage

General Usage

Table of Contents

Payments

P2PK (Pay To Public Key)

P2PKH (Public Key Hash)

P2WPKH (Witness Public Key Hash)

P2SH (Script Hash)

P2WSH (Witness Script Hash)

P2SH-P2WSH

P2MS (classic multisig)

P2TR (Taproot)

P2TR-NS (Taproot multisig)

P2TR-MS (Taproot M-of-N multisig)

P2TR-PK (Taproot single P2PK script)

Transaction

Encode/decode

Inputs

Outputs

Basic transaction sign

BIP174 PSBT multi-sig example

Utils

getAddress

WIF

Script

OutScript

License