Multichain Seed SDK

A TypeScript SDK for deriving deterministic blockchain addresses from a single BIP-39 mnemonic/seed across multiple chains.

Features

• Seed-only: No encryption or signing - purely address derivation
• Multi-chain support: BTC, ETH, BSC, DOGE, LTC, TRX, XRP, SOL
• BIP-39/BIP-32 compliant: Standard HD wallet derivation paths
• Watch-only addresses: Derive addresses from xpubs without private keys
• Testnet support: Generate testnet addresses for development and testing
• Tree-shakable: Only import what you need
• TypeScript: Full type safety and IntelliSense

Installation

npm install @nawab_kibria/multichain-sdk

Quick Start

Basic Address Derivation

import { mnemonicToSeed, deriveAddressForChain } from '@nawab_kibria/multichain-sdk'

const mnemonic = "your twelve or twenty four words here"
const seed = await mnemonicToSeed(mnemonic)

// Derive addresses for different chains
const eth0 = deriveAddressForChain('ETH', seed, { index: 0 })
const btc5 = deriveAddressForChain('BTC', seed, { index: 5 })
const sol0 = deriveAddressForChain('SOL', seed) // uses m/44'/501'/0'/0' by default

console.log(eth0.address, eth0.path) // 0x...
console.log(btc5.address, btc5.path) // bc1...
console.log(sol0.address, sol0.path) // 1111... (base58)

// Generate testnet addresses
const btcTestnet = deriveAddressForChain('BTC', seed, { index: 0, testnet: true })
console.log(btcTestnet.address, btcTestnet.path) // tb1... (testnet)

Watch-Only Address Derivation

import { mnemonicToSeed, deriveXPubForChain, deriveWatchOnlyAddress } from '@nawab_kibria/multichain-sdk'

const mnemonic = "your twelve or twenty four words here"
const seed = await mnemonicToSeed(mnemonic)

// Derive xpub for watch-only functionality
const xpub = deriveXPubForChain('ETH', seed, { account: 0, change: 0, index: 0 })
console.log('XPub:', xpub.xpub) // xpub6... (secure, no private keys)

// Derive addresses from xpub (watch-only)
const watchOnly0 = deriveWatchOnlyAddress('ETH', xpub.xpub, 0, 0)
const watchOnly1 = deriveWatchOnlyAddress('ETH', xpub.xpub, 0, 1)
const watchOnly2 = deriveWatchOnlyAddress('ETH', xpub.xpub, 0, 2)

console.log('Watch-only addresses:', watchOnly0.address, watchOnly1.address, watchOnly2.address)

// These addresses match the seed-derived addresses exactly!
const direct0 = deriveAddressForChain('ETH', seed, { index: 0 })
console.log('Match:', watchOnly0.address === direct0.address) // true

Supported Chains

| Chain | Derivation | Address Type | Watch-Only | Notes | | ---------- | ------------------------------ | ----------------------- | ---------- | ------------------------------------ | | Bitcoin | BIP84 (m/84'/0'/0'/0/i) | Bech32 P2WPKH | ✅ | Modern SegWit | | Ethereum | BIP44 (m/44'/60'/0'/0/i) | EVM checksum | ✅ | Compatible with MetaMask | | Binance SC | BIP44 (m/44'/60'/0'/0/i) | EVM checksum | ✅ | Same as ETH | | Dogecoin | BIP44 (m/44'/3'/0'/0/i) | Legacy P2PKH | ✅ | No SegWit support | | Litecoin | BIP84 (m/84'/2'/0'/0/i) | Bech32 P2WPKH | ✅ | Modern SegWit | | Tron | BIP44 (m/44'/195'/0'/0/i) | Base58Check TRX | ✅ | Tron-specific encoding | | XRP | BIP44 (m/44'/144'/0'/0/i) | Ripple Base58 | ✅ | Classic XRPL address format | | Solana | SLIP-0010 (m/44'/501'/0'/0') | Ed25519 Pubkey (base58) | ❌ | Ed25519 curve, no BIP32 xpub |

Testnet Support

All chains support testnet address generation by setting testnet: true in the options:

| Chain | Testnet Network | Address Format Changes | | ---------- | --------------- | ---------------------------------------- | | Bitcoin | Testnet | tb1 prefix instead of bc1 | | Ethereum | Sepolia | Same address format, different network | | Binance SC | BSC Testnet | Same address format, different network | | Dogecoin | Testnet | Different address format | | Litecoin | Testnet | tltc prefix instead of ltc1 | | Tron | Shasta | Same address format, different API | | XRP | Testnet | Same address format, different network | | Solana | Devnet | Same address format, different network |

API Reference

mnemonicToSeed(mnemonic: string, passphrase?: string): Promise<Buffer>

Converts a BIP-39 mnemonic to a seed buffer.

deriveAddressForChain(chain: Chain, seed: Buffer, opts?: DeriveOpts): DerivedAddress

Derives an address for a specific blockchain.

Parameters

• chain: The blockchain to derive an address for
• seed: The seed buffer from mnemonicToSeed
• opts: Optional derivation parameters

DeriveOpts

interface DeriveOpts {
  account?: number    // Account number (hardened, default: 0)
  change?: 0 | 1      // 0 = external, 1 = internal/change (default: 0)
  index?: number      // Address index (default: 0)
  customPath?: string // Override full derivation path (advanced)
  testnet?: boolean   // Use testnet instead of mainnet (default: false)
}

Return Value

interface DerivedAddress {
  chain: Chain           // The blockchain identifier
  path: string          // The derivation path used
  address: string       // The blockchain address
  privateKeyHex?: string // Private key in hex (no 0x prefix)
  xpub?: string         // Extended public key (when applicable)
}

deriveXPubForChain(chain: Chain, seed: Buffer, opts?: DeriveOpts): XPubResult

Derives an extended public key (xpub) for watch-only functionality.

Return Value

interface XPubResult {
  chain: Chain                    // The blockchain identifier
  path: string                   // The derivation path used
  xpub: string                   // Extended public key (secure, no private keys)
  network: 'mainnet' | 'testnet' // Network type
}

Note: Solana is not supported for xpub derivation due to ed25519 curve limitations.

deriveWatchOnlyAddress(chain: Chain, xpub: string, change: 0|1, index: number, testnet?: boolean): WatchOnlyAddress

Derives a watch-only address from an xpub without requiring private keys.

Parameters

• chain: The blockchain to derive an address for
• xpub: Extended public key from deriveXPubForChain
• change: 0 = external, 1 = internal/change
• index: Address index
• testnet: Use testnet (default: false)

Return Value

interface WatchOnlyAddress {
  chain: Chain    // The blockchain identifier
  path: string   // The derivation path used
  address: string // The blockchain address
  xpub: string   // The xpub used for derivation
}

Note: Solana is not supported for watch-only derivation. Use deriveAddressForChain directly for Solana addresses.

Development

# Install dependencies
npm install

# Run demo
npm run dev

# Build
npm run build

# Type check
npm run typecheck

# Run examples
npm run examples          # Basic usage
npm run examples:advanced # Advanced derivation
npm run examples:typescript # TypeScript example
npm run examples:testnet # Testnet usage

Demo

Run npm run dev to see addresses derived for all supported chains from a randomly generated mnemonic.

Security Notes

• This SDK does NOT encrypt or secure your seed/mnemonic
• Keep your mnemonic secure and never share it
• This is for address derivation only - no transaction signing
• Use in production only with proper security measures
• Xpubs are secure for sharing - they contain no private keys
• Watch-only addresses are derived from public keys only

Roadmap

• [x] Watch-only address derivation from xpubs
• [x] TRX watch-only support (Keccak-256 address generation)
• [x] Comprehensive test coverage for xpub functionality
• [ ] Seed/xpriv encryption (AES-GCM + Argon2)
• [ ] Transaction signing support
• [ ] Balance queries via RPC
• [ ] More blockchain support
• [ ] Wallet backup/restore utilities

License

MIT

Repository Setup Complete