chaingate

ChainGate

Multi-chain cryptocurrency SDK for TypeScript.
Create wallets, query blockchains, and send transactions across Bitcoin, Ethereum, and more.

📖 Documentation   |   🔑 Get your free API key

Features

• 👛 Wallet management -- Create HD wallets from mnemonics, import from seed, xpriv, xpub, private key, WIF, or keystores
• ⛓️ Multi-chain -- Bitcoin, Litecoin, Dogecoin, Bitcoin Cash, Ethereum, and any EVM chain via RPC
• 📍 Address derivation -- BIP-44/84/86 with segwit, legacy, taproot, cashaddr, and EOA
• 🔍 Blockchain explorer -- Balances, transactions, UTXOs, blocks, fees, tokens, and NFT metadata
• 📤 Transactions -- Send coins, ERC-20 tokens, NFTs, and call smart contracts with suggested fees
• 🔒 Encryption -- AES-256-GCM wallet encryption with password protection
• ✍️ Message signing -- EIP-191 (EVM) and Bitcoin-standard signing and verification
• 💱 Fiat conversion -- Live conversion to 160+ currencies
• 👁️ View-only wallets -- Read-only access from xpub or public key

Install

npm install chaingate

Examples

Send $20 in Bitcoin

import { ChainGate, importWallet } from 'chaingate';

const cg = new ChainGate({ apiKey: 'your-api-key' });
const wallet = importWallet({ phrase: 'abandon abandon abandon ...' });
const btc = cg.connect(cg.networks.bitcoin, wallet);

// Convert $20 USD to the equivalent BTC amount at current market rate
const amount = await cg.networks.bitcoin.amountFromCurrency('usd', 20);

const tx = await btc.transfer(amount, 'bc1qRecipient...');

// Review suggested fees and pick one
const fees = tx.recommendedFees();
console.log(fees.normal.estimatedFeeSat); // estimated fee in satoshis
console.log(fees.normal.enoughFunds); // true if balance covers amount + fee
tx.setFee(fees.high);

const broadcasted = await tx.signAndBroadcast();
console.log('txid:', broadcasted.transactionId);

Token Balances (ERC-20, ERC-721, ERC-1155)

const eth = cg.connect(cg.networks.ethereum, wallet);

const tokens = await eth.addressTokenBalances();

for (const token of tokens) {
  if (token.isNFT) {
    // ERC-721 or ERC-1155
    console.log(`${token.name} -- ${token.ownedTokens.length} NFTs`);
  } else {
    // ERC-20
    console.log(`${token.base()} ${token.symbol}`); // e.g. "1500.50 USDC"
  }
}

Transaction History (EVM)

Full decoded history with token transfers, approvals, wraps, and more:

const eth = cg.connect(cg.networks.ethereum, wallet);
const history = await eth.addressHistory();

for (const tx of history.transactions) {
  console.log(tx.txHash, new Date(tx.timestamp * 1000));

  // Decoded actions relevant to your address
  for (const action of tx.actions) {
    // action.type: "transfer_in", "transfer_out", "mint", "burn", "wrap", "unwrap", ...
    // action.token: { name, symbol, decimals, logoUrl }
    // action.contract: contract address or "native" for ETH transfers
    console.log(`  ${action.type} on ${action.token.symbol ?? 'ETH'}`);
  }
}

Transaction History (UTXO)

const btc = cg.connect(cg.networks.bitcoin, wallet);
const history = await btc.addressHistory();

for (const tx of history.transactions) {
  const usd = await tx.amount.toCurrency('usd');
  console.log(`${tx.txid}: ${tx.amount.base()} BTC ($${usd})`);
}

Create a Wallet and Check Balance

import { ChainGate, newWallet } from 'chaingate';

const cg = new ChainGate({ apiKey: 'your-api-key' });

const { phrase, wallet } = newWallet();
console.log('Mnemonic:', phrase);

const eth = cg.connect(cg.networks.ethereum, wallet);
const balance = await eth.addressBalance();
const usd = await balance.confirmed.toCurrency('usd');
console.log(`${balance.confirmed.base()} ${balance.confirmed.symbol} ($${usd})`);

Import a Wallet

import { importWallet, createWalletFromString } from 'chaingate';

// From mnemonic
const wallet = importWallet({ phrase: 'abandon abandon abandon ...' });

// From private key
importWallet({ privateKey: '0x...' });

// From xpub (view-only)
importWallet({ xpub: 'xpub...' });

// Auto-detect any format
const wallet = createWalletFromString('xprv9s21ZrQH143K...');

Send ERC-20 Tokens

const eth = cg.connect(cg.networks.ethereum, wallet);

const usdc = cg.networks.ethereum.amount('100', {
  contractAddress: '0xA0b8...eB48',
  decimals: 6,
  symbol: 'USDC',
});

const tx = await eth.transferToken(usdc, '0xRecipient...');
await tx.signAndBroadcast();

Send NFTs

// ERC-721
const tx = await eth.transferNft('0xNftContract...', '0xRecipient...', tokenId);

// ERC-1155 (with quantity)
const tx = await eth.transferErc1155('0xNftContract...', tokenId, 5, '0xRecipient...');

Connect to Any EVM Chain

const bsc = cg.networks.evmRpc({
  rpcUrl: 'https://bsc-dataseed.binance.org',
  chainId: 56,
  name: 'BNB Smart Chain',
  symbol: 'BNB',
});

const conn = cg.connect(bsc, wallet);
const balance = await conn.addressBalance();

Encrypt and Save a Wallet

await wallet.encrypt('my-password');
const data = wallet.serialize();

// Restore later
import { deserializeWallet } from 'chaingate';
const restored = deserializeWallet(data, async () => {
  return prompt('Enter password:');
});

Validate Addresses

cg.networks.bitcoin.isValidAddress('bc1qw508d6qejxtdg4y5r3zarvary0c5xw7kv8f3t4'); // true
cg.networks.ethereum.isValidAddress('0xAb5801a7D398351b8bE11C439e05C5B3259aeC9B'); // true
cg.networks.bitcoincash.isValidAddress('bitcoincash:qpm2qsznhks23z7629mms6s4cwef74vcwvy22gdx6a'); // true

cg.networks.bitcoin.isValidAddress('0xAb5801a7D398351b8bE11C439e05C5B3259aeC9B'); // false
cg.networks.ethereum.isValidAddress('not-an-address'); // false

Sign Messages

import { signEvmMessage, verifyEvmMessage } from 'chaingate';

// EVM (EIP-191)
const signature = signEvmMessage('Hello', privateKey);
const isValid = verifyEvmMessage('Hello', signature, address);

Supported Networks

Network	Address Types
Bitcoin	segwit, legacy, taproot
Litecoin	segwit, legacy
Dogecoin	legacy
Bitcoin Cash	cashaddr, legacy
Bitcoin Testnet	segwit, legacy, taproot
Ethereum	EOA
Any EVM via RPC	EOA

RPC proxy URLs included for Ethereum, Polygon, Arbitrum, Avalanche, BNB Chain, Base, and Sonic.

📖 Read the full docs