msigner: Multi-Chain Ordinals Atomic Swap PSBT Signer

msigner is an open source Bitcoin Ordinals Partially Signed Bitcoin Transactions (PSBT) signer library. It supports atomic swap of inscriptions and provides a simple and secure way to structure Bitcoin transactions for marketplaces.

GitHub: https://github.com/dedooxyz/msigner

Multi-Chain Support

This fork adds support for any Bitcoin-like blockchain:

Chain	Symbol	Status	SegWit	Taproot	Address Prefix
Bitcoin	BTC	✅ Full	✅	✅	1, 3, bc1
Junkcoin	JKC	✅ Full	❌	❌	7, J
Bitcoin Classic	XBT	✅ Full	❌	❌	1, 3, bc1
Briskcoin	BKC	✅ Full	✅	❌	B
Craftcoin	CRC	✅ Full	❌	❌	Q, craft1
DogecoinEV	DEV	✅ Full	❌	❌	D
FRSC	FRSC	✅ Full	❌	❌	F
Lebowski	LBW	✅ Full	❌	❌	6, lbw1
Litecoin	LTC	✅ Full	✅	❌	L, ltc1
Dogecoin	DOGE	✅ Full	❌	❌	D

Installation

# Install from GitHub
npm install github:dedooxyz/msigner

# Or add to package.json
"dependencies": {
  "msigner": "github:dedooxyz/msigner"
}

Quick Start

For Bitcoin (Original Usage)

import { SellerSigner, BuyerSigner } from 'msigner';

// Use default Bitcoin mainnet configuration
const listing = await SellerSigner.generateUnsignedListingPSBTBase64({
  network: bitcoin.networks.bitcoin,
  seller: {
    makerFeeBp: 100,
    sellerOrdAddress: 'bc1p...',
    price: 100000, // satoshis
    ordItem: { ... },
    sellerReceiveAddress: 'bc1p...',
  },
});

For Junkcoin

import {
  SellerSigner,
  junkcoinMainnet,
  FullnodeRPC,
  StaticFeeProvider,
} from 'msigner';

// Create Junkcoin RPC provider
const rpcProvider = new FullnodeRPC({
  host: 'http://localhost',
  port: 9771,
  user: 'rpcuser',
  pass: 'rpcpass',
});

// Use static fees for chains without mempool.space
const feeProvider = new StaticFeeProvider({
  fastestFee: 10,
  halfHourFee: 5,
  hourFee: 2,
  minimumFee: 1,
});

// Create listing with Junkcoin network
const listing = await SellerSigner.generateUnsignedListingPSBTBase64(
  {
    network: junkcoinMainnet.network,
    seller: {
      makerFeeBp: 100,
      sellerOrdAddress: '7xxxxxxxxxxxxxxxxxxxxxxxxxxxxR4HN',
      price: 100000000, // 1 JKC in satoshis
      ordItem: { ... },
      sellerReceiveAddress: '7xxxxxxxxxxxxxxxxxxxxxxxxxxxxR4HN',
    },
  },
  rpcProvider,
);

Adding a Custom Chain

import { createNetwork, SellerSigner } from 'msigner';
import * as bitcoin from 'bitcoinjs-lib';

// Define your chain's network parameters
const myChain = createNetwork({
  name: 'mychain',
  symbol: 'MYC',
  network: {
    messagePrefix: '\x19MyChain Signed Message:\n',
    bech32: '', // Empty for legacy-only chains
    bip32: {
      public: 0x0488b21e,
      private: 0x0488ade4,
    },
    pubKeyHash: 0x1e, // Your chain's address prefix
    scriptHash: 0x05,
    wif: 0x80,
  },
  supportsSegwit: false,
  supportsTaproot: false,
  defaultRpcPort: 12345,
});

// Use with the signer
const listing = await SellerSigner.generateUnsignedListingPSBTBase64(
  { network: myChain.network, seller: { ... } },
  myRpcProvider,
);

Features

• 2-Dummy UTXO algorithm: Provides maximal protection to the offset of the ordinals
• Seller-Buyer-friendly API: SIGHASH_SINGLE|ANYONECANPAY for sellers, SIGHASH_DEFAULT for buyers
• Trust-minimized PSBT combining: Zero communication required between seller and buyer
• Multi-chain support: Bitcoin, Junkcoin, Briskcoin, Craftcoin, and more
• Legacy address support: Works with chains that don't support SegWit or Taproot

How it Works

As a seller:

• Sign a single PSBT using SIGHASH_SINGLE | ANYONECANPAY

As a buyer:

• Sign a full PSBT using SIGHASH_DEFAULT

As a platform combiner:

• Verify seller and buyer signatures
• Merge seller and buyer signatures
• Finalize and run mempool acceptance test
• Broadcast the transaction

API Reference

Networks

import {
  bitcoinMainnet,
  bitcoinTestnet,
  junkcoinMainnet,
  briskcoinMainnet,
  craftcoinMainnet,
  dogecoinEvMainnet,
  frscMainnet,
  lebowskiMainnet,
  litecoinMainnet,
  dogecoinMainnet,
  getNetwork,
  createNetwork,
} from 'msigner';

// Get network by name or symbol
const jkc = getNetwork('junkcoin');  // or 'jkc'
const bkc = getNetwork('briskcoin'); // or 'bkc'

Providers

import {
  FullnodeRPC,       // RPC provider for full nodes
  MempoolProvider,   // Mempool.space API provider
  StaticFeeProvider, // Fixed fee rates (for chains without mempool API)
} from 'msigner';

Signers

import { SellerSigner, BuyerSigner } from 'msigner';

// Seller operations
SellerSigner.generateUnsignedListingPSBTBase64(listing, rpcProvider);
SellerSigner.verifySignedListingPSBTBase64(req, config);

// Buyer operations
BuyerSigner.selectDummyUTXOs(utxos, itemProvider, rpcProvider);
BuyerSigner.selectPaymentUTXOs(utxos, amount, ...);
BuyerSigner.generateUnsignedBuyingPSBTBase64(listing, feeProvider, rpcProvider);
BuyerSigner.mergeSignedBuyingPSBTBase64(sellerPsbt, buyerPsbt, network);

Development

# Clone the repository
git clone https://github.com/dedooxyz/msigner.git
cd msigner

# Install dependencies
npm install

# Build
npm run build

# Run tests
npm test

# Format code
npm run format

License

Apache 2.0