✨ Bitcoin TypeScript/JavaScript Library for NodeJS, Browser and Mobile ✨
Bitcoin is hard. Especially for those not familiar with crypto, it is even hard to create a simple bitcoin transaction.
bitcoin-sdk-js provides various features which help to create various type of bitcoin transaction so easily🚀, including advanced smart contract like multisig, hashlock, timelock, combination of them, and even your own smart contract.
Legacy, Segwit, Taproot features are all suppoted!
npm install bitcoin-sdk-jsimport * as bitcoin from 'bitcoin-sdk-js'
// if you need to generate key pair const keyPair = await bitcoin.wallet.generateKeyPair(); // p2pkh const legacyAddress = await bitcoin.address.generateAddress( keyPair.publicKey, 'legacy', ); // p2wpkh const segwitAddress = await bitcoin.address.generateAddress( keyPair.publicKey, 'segwit', ); // p2tr const taprootAddress = await bitcoin.address.generateAddress( ( // It's recommended to tweak public key to generate taproot address await bitcoin.tapscript.getTapTweakedPubkey( // Schnorr key is same with any bitcoin key pair, except it does not use public key prefix byte '02' or '03'. keyPair.publicKey.slice(2), await bitcoin.tapscript.getTapTweak(keyPair.publicKey.slice(2)), ) ).tweakedPubKey, 'taproot', ); // p2pkh - testnet const legacyAddressTestnet = await bitcoin.address.generateAddress( keyPair.publicKey, 'legacy', 'testnet', ); // p2wpkh - testnet const segwitAddressTestnet = await bitcoin.address.generateAddress( keyPair.publicKey, 'segwit', 'testnet', ); // p2tr - testnet const taprootAddressTestnet = await bitcoin.address.generateAddress( ( // It's recommended to tweak public key to generate taproot address await bitcoin.tapscript.getTapTweakedPubkey( // Schnorr key is same with any bitcoin key pair, except it does not use public key prefix byte '02' or '03'. keyPair.publicKey.slice(2), await bitcoin.tapscript.getTapTweak(keyPair.publicKey.slice(2)), ) ).tweakedPubKey, 'taproot', 'testnet', );
#### 2. Address for Script(P2SH, P2WSH)
``` javascript
import * as bitcoin from 'bitcoin-sdk-js'
// if you need to generate key pair
const keyPair = await bitcoin.wallet.generateKeyPair();
// Script can be any of bitcoin script opcode! bitcoin-sdk-js provides an easy way to build script.
// Below script is timelock + single sig
const script =
await bitcoin.script.generateTimeLockScript(2542622) + await bitcoin.script.generateSingleSigScript(keyPair.publicKey);
// p2sh
const legacyScriptAddress = await bitcoin.address.generateScriptAddress(
script,
'legacy',
);
// p2wsh
const segwitScriptAddress = await bitcoin.address.generateScriptAddress(
script,
'segwit',
);
// p2sh - testnet
const legacyScriptAddressTestnet = await bitcoin.address.generateScriptAddress(
script,
'legacy',
'testnet',
);
// p2wsh - testnet
const segwitScriptAddressTestnet = await bitcoin.address.generateScriptAddress(
script,
'segwit',
'testnet',
);
import * as bitcoin from 'bitcoin-sdk-js';
// if you need to generate key pair
const keyPair = await bitcoin.wallet.generateKeyPair();
const pubkey = keyPair.publicKey;
const privkey = keyPair.privateKey;
// initialize Bitcoin Transaction object
const tx = new bitcoin.Transaction();
// add UTXO to spend as an input
await tx.addInput({
txHash: txId, // transaction id of utxo
index: 0, // index of utxo in transaction
value: value, // value of utxo(unit is satoshi)
} as bitcoin.UTXO);
// add Target output to send Bitcoin
// most common transaction which sends bitcoin to single sig address
await tx.addOutput({
address: await bitcoin.address.generateAddress(pubkey),
value: value - fee, // value of utxo - fee
} as bitcoin.Target);
// if input utxo only requires single sig(p2wpkh or p2pkh)
await tx.signInput(privkey, 0);
// You can broadcast signed tx here: https://blockstream.info/testnet/tx/push
const txToBroadcast: string = await tx.getSignedHex();
import * as bitcoin from 'bitcoin-sdk-js';
// initialize Bitcoin Transaction object
const tx = new bitcoin.Transaction();
// add UTXO to spend as an input
await tx.addInput({
txHash: txId, // transaction id of utxo
index: 0, // index of utxo in transaction
value: value, // value of utxo(unit is satoshi)
} as bitcoin.UTXO);
// add Target output to send Bitcoin
// sends bitcoin to 2-of-3 multisig transaction
await tx.addOutput({
// all the smart contract output is recommended to use script address!
address: await bitcoin.address.generateScriptAddress(
// this generate multisig smart contract, which is possible up to 15-of-15
await bitcoin.script.generateMultiSigScript(2, [pubkey1, pubkey2, pubkey3]),
),
value: value - fee, // value of utxo - fee
} as bitcoin.Target);
// if input utxo requires multi sig(p2wsh or p2sh)
await tx.multiSignInput(
[pubkey1, pubkey2, pubkey3],
[privkey1, privkey2],
0, // input index to sign
);
// You can broadcast signed tx here: https://blockstream.info/testnet/tx/push
const txToBroadcast: string = await tx.getSignedHex();
import * as bitcoin from 'bitcoin-sdk-js';
// initialize Bitcoin Transaction object
const tx = new bitcoin.Transaction();
// add UTXO to spend as an input
await tx.addInput({
txHash: txId, // transaction id of utxo
index: 0, // index of utxo in transaction
value: value, // value of utxo(unit is satoshi)
} as bitcoin.UTXO);
// add Target output to send Bitcoin
// sends bitcoin to single(or multi) sig script with timelock
await tx.addOutput({
address: await bitcoin.address.generateScriptAddress(
// able to spend this output after given block height
(await bitcoin.script.generateTimeLockScript(2542622)) +
// you can use generateMultiSigScript instead of single sig here
(await bitcoin.script.generateSingleSigScript(pubkey)),
),
value: value - fee, // value of utxo - fee
} as bitcoin.Target);
// sends bitcoin to single(or multi) sig script with hashlock
await tx.addOutput({
address: await bitcoin.address.generateScriptAddress(
// able to spend this output if 'secretHex' is given
(await bitcoin.script.generateHashLockScript('secretHex')) +
// you can use generateMultiSigScript instead of single sig here
(await bitcoin.script.generateSingleSigScript(pubkey)),
),
value: value - fee, // value of utxo - fee
} as bitcoin.Target);
// sends bitcoin to single(or multi) sig script with timelock + hashlock
await tx.addOutput({
address: await bitcoin.address.generateScriptAddress(
/*
WATCH OUT! Order matters. You must place script in the order of
timelock, hashlock and single(or multi) sig
to spend this output with bitcoin-sdk-js
*/
(await bitcoin.script.generateTimeLockScript(2542622)) +
(await bitcoin.script.generateHashLockScript('secretHex')) +
// you can use generateMultiSigScript instead of single sig here
(await bitcoin.script.generateSingleSigScript(pubkey)),
),
value: value - fee, // value of utxo - fee
} as bitcoin.Target);
// if transaction use timelock input, must set tx locktime bigger than input timelock
await tx.setLocktime(2542622);
// if input utxo requires single sig with smart contract(p2wsh or p2sh)
await tx.signInput(
privkey,
0, // input index to sign
'segwit', // default is segwit, you might use legacy if necessary
await bitcoin.script.generateTimeLockScript(2542622), // is timelock input? provide script
'secretHex', // is hashlock input? provide secretHex to unlock
);
// or if input utxo requires multi sig with smart contract(p2wsh or p2sh)
await tx.multiSignInput(
[pubkey1, pubkey2, pubkey3],
[privkey1, privkey2],
0, // input index to sign
'segwit', // default is segwit, you might use legacy if necessary
await bitcoin.script.generateTimeLockScript(2542622), // is timelock input? provide script
'secretHex', // is hashlock input? provide secretHex to unlock
);
// You can broadcast signed tx here: https://blockstream.info/testnet/tx/push
const txToBroadcast: string = await tx.getSignedHex();
import * as bitcoin from 'bitcoin-sdk-js';
// initialize Bitcoin Transaction object
const tx = new bitcoin.Transaction();
// add UTXO to spend as an input
await tx.addInput({
txHash: txId, // transaction id of utxo
index: 0, // index of utxo in transaction
value: value, // value of utxo(unit is satoshi)
} as bitcoin.UTXO);
// add Target output to send Bitcoin
// sends bitcoin to script with timelock + hashlock (no sig required)
await tx.addOutput({
address: await bitcoin.address.generateScriptAddress(
// if you only want hashlock, you can remove generateTimeLockScript
(await bitcoin.script.generateTimeLockScript(2542622)) +
(await bitcoin.script.generateHashLockScript('secretHex')),
),
value: value - fee, // value of utxo - fee
} as bitcoin.Target);
// if transaction use timelock input, must set tx locktime bigger than input timelock
await tx.setLocktime(2542622);
// if input utxo requires to unlock hash with smart contract(p2wsh or p2sh)
await tx.unlockHashInput(
'secretHex',
0,
'segwit', // default is segwit, you might use legacy if necessary
await bitcoin.script.generateTimeLockScript(2542622),// is timelock input? provide script
);
// You can broadcast signed tx here: https://blockstream.info/testnet/tx/push
const txToBroadcast: string = await tx.getSignedHex();
You might use tapscript for this!
import * as bitcoin from 'bitcoin-sdk-js';
// You can send and spend any smart contract. Below example is classic HTLC
const HTLC = bitcoin.Opcode.OP_IF +
(await bitcoin.script.generateTimeLockScript(2576085)) +
(await bitcoin.data.pushData(pubkey1)) + // must specify data to read(if not opcode)
pubkey1 +
bitcoin.Opcode.OP_ELSE +
(await bitcoin.script.generateHashLockScript('abcdef')) +
(await bitcoin.data.pushData(pubkey2)) + // must specify data to read(if not opcode)
pubkey2 +
bitcoin.Opcode.OP_ENDIF +
bitcoin.Opcode.OP_CHECKSIG
// p2wsh address, custom contract address must be p2wsh(p2sh) (or taproot address, check next chapter!)
const toAddress = await bitcoin.address.generateScriptAddress(HTLC);
// Then, can be spent as an input by signing by scriptSig!
// initialize Bitcoin Transaction object
const tx = new bitcoin.Transaction();
// if transaction use timelock input, must set tx locktime bigger than input timelock
await tx.setLocktime(2576085);
// spend by executing OP_IF branch
await tx.signInputByScriptSig(
// script sig list(order matters!!! bitcoin script is stack-based LIFO)
[
await bitcoin.crypto.sign(
// method to get input message hash to sign
await tx.getInputHashToSign(
HTLC, // redeem script as p2wsh
0, // input index
),
privkey1, // signer private key
),
'01', // execute OP_IF
HTLC, // redeem script as p2wsh
],
0, // input index
);
// Or spend by executing OP_ELSE branch
await tx.signInputByScriptSig(
// script sig list(order matters!!! bitcoin script is stack-based LIFO)
[
await bitcoin.crypto.sign(
// method to get input message hash to sign
await tx.getInputHashToSign(
HTLC, // redeem script as p2wsh
0, // input index
),
privkey2, // signer private key
),
'abcdef', // unlock hash
'', // execute OP_ELSE
HTLC, // redeem script as p2sh
],
0, // input index
);
// You can broadcast signed tx here: https://blockstream.info/testnet/tx/push
const txToBroadcast: string = await tx.getSignedHex();
import * as bitcoin from 'bitcoin-sdk-js';
// Let's send and spend above HTLC in taproot and tapscript way!
/*
Schnorr key is same with any bitcoin key pair, except it does not use public key prefix byte '02' or '03'.
This key pair will be used as a master key to spend UTXO in taproot, after tweaked(will explain how to step by step).
*/
const keyPair = await bitcoin.wallet.generateKeyPair();
const schnorrPubkey = keyPair.publicKey.slice(2); // remove first byte (which is parity bit)
const schnorrPrivkey = keyPair.privateKey;
/*
HTLC consists of conditional branch, in which OP_IF contains Time Lock Contract and OP_ELSE contains Hash Lock.
We can construct tapscript tree where each leaf has its own contract(script), enable unlimited spending branches.
*/
// Originally OP_IF branch Time Lock Contract
const timeLockContract =
(await bitcoin.script.generateTimeLockScript(2576085)) +
(await bitcoin.data.pushData(schnorrPubkey1)) + // must specify data to read(if not opcode)
schnorrPubkey1 + // you must use schnorr key even in tapscript
bitcoin.Opcode.OP_CHECKSIG;
// Originally OP_ELSE branch Hash Lock Contract
const hashLockContract =
(await bitcoin.script.generateHashLockScript('abcdef')) +
(await bitcoin.data.pushData(schnorrPubkey2)) + // must specify data to read(if not opcode)
schnorrPubkey2 + // you must use schnorr key even in tapscript
bitcoin.Opcode.OP_CHECKSIG;
/*
You can get tapbranch from a pair of script, and repeat over to reach to the root of tree(which is 'taproot')
Here we have only a single pair of script, so tapbranch of it is taproot
*/
const taproot = await bitcoin.tapscript.getTapBranch([
await bitcoin.tapscript.getTapLeaf(timeLockContract),
await bitcoin.tapscript.getTapLeaf(hashLockContract),
]);
// Then, get taptweak with schnorr key generated above
const tapTweak = await bitcoin.tapscript.getTapTweak(
schnorrPubkey,
taproot,
);
// Finally, you can tweak schnorr public key, which can be used as taproot key!
const tapTweakedPubkey = await bitcoin.tapscript.getTapTweakedPubkey(
schnorrPubkey,
tapTweak,
);
// generate taproot address with taproot key(and send to it!)
const toAddress = await bitcoin.address.generateAddress(tapTweakedPubkey.tweakedPubKey, 'taproot');
// initialize Bitcoin Transaction object
const tx = new bitcoin.Transaction();
await tx.setLocktime(2576085); // if transaction use timelock input, must set tx locktime bigger than input timelock
// Then, can be spent as an input!
// one thing to keep in mind, taproot or tapscript spend needs to provide all the script public key of input
await tx.addInput({
txHash: txId,
index: 0,
value: value,
script: await bitcoin.script.getScriptByAddress(toAddress),
});
// taproot spend? just sign input with tweaked schnorr key(which is, taproot private key)
await tx.signInput(
await bitcoin.tapscript.getTapTweakedPrivkey(schnorrPrivkey, tapTweak), // provide tweaked private key
0,
'taproot',
);
// Or tapscript spend? Let's spend by hash lock script!
const sigStack = [
await bitcoin.crypto.sign(
await tx.getInputHashToSign(hashLockContract, 0, 'tapscript'),
schnorrPrivkey2,
'schnorr',
), // schnorr signature
'abcdef', // hash to unlock
hashLockContract, // spend script
// you must specify path to find taproot with provided script(For more detail, check BIP341!)
await bitcoin.tapscript.getTapControlBlock(
schnorrPubkey,
tapTweakedPubkey.parityBit,
await bitcoin.tapscript.getTapLeaf(timeLockContract), // path to find taproot
),
];
await tx.signInputByScriptSig(sigStack, 0, 'tapscript');
// You can broadcast signed tx here: https://blockstream.info/testnet/tx/push
const txToBroadcast: string = await tx.getSignedHex();
import * as bitcoin from 'bitcoin-sdk-js'
// if you need to generate key pair
const keyPair = await bitcoin.wallet.generateKeyPair();
const pubkey = keyPair.publicKey;
const privkey = keyPair.privateKey;
// address to verify(legacy p2pkh, segwit p2wpkh, taproot p2tr are all supported!)
const legacyAddress = await bitcoin.address.generateAddress(
pubkey,
'legacy',
);
const segwitAddress = await bitcoin.address.generateAddress(
pubkey,
'segwit',
);
const tapAddress = await bitcoin.address.generateAddress(
(
await bitcoin.tapscript.getTapTweakedPubkey(
pubkey.slice(2),
await bitcoin.tapscript.getTapTweak(pubkey.slice(2)),
)
).tweakedPubKey,
'taproot',
);
// message to sign
const msg = "message to sign";
// sign messsage with private key and address
const sigLegacy = await bitcoin.crypto.signMessage(
msg,
privkey,
legacyAddress,
);
const sigSegwit = await bitcoin.crypto.signMessage(
msg,
privkey,
segwitAddress,
);
const sigTap = await bitcoin.crypto.signMessage(msg, privkey, tapAddress);
// verify signature from address, returning boolean.
await bitcoin.crypto.verifyMessage(msg, sigLegacy, legacyAddress);
await bitcoin.crypto.verifyMessage(msg, sigSegwit, segwitAddress);
await bitcoin.crypto.verifyMessage(msg, sigTap, tapAddress);
This software is licensed under the MIT ©.