get-balances.ts

import {
  createPublicClient,
  http,
  formatUnits,
  parseAbi,
  type Address,
} from 'viem'
import { mainnet } from 'viem/chains'

const erc20Abi = parseAbi([
  'function balanceOf(address _owner) view returns (uint256 balance)',
  'function decimals() view returns (uint8)',
  'function symbol() view returns (string)',
])

const client = createPublicClient({
  chain: mainnet,
  transport: http(),
})

interface Token {
  address: Address
  symbol: string
  decimals: number
}

interface TokenBalance {
  symbol: string
  address: Address
  balance: string
  rawBalance?: string
  error?: string
}

const tokens: Token[] = [
  {
    address: '0xa0b86991c6218b36c1d19d4a2e9eb0ce3606eb48',
    symbol: 'USDC',
    decimals: 6,
  },
  {
    address: '0xdAC17F958D2ee523a2206206994597C13D831ec7',
    symbol: 'USDT',
    decimals: 6,
  },
  {
    address: '0x2260FAC5E5542a773Aa44fBCfeDf7C193bc2C599',
    symbol: 'WBTC',
    decimals: 8,
  },
  {
    address: '0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2',
    symbol: 'WETH',
    decimals: 18,
  },
  {
    address: '0xB8c77482e45F1F44dE1745F52C74426C631bDD52',
    symbol: 'BNB',
    decimals: 18,
  },
]

async function getTokenBalances(
  walletAddress: Address,
): Promise<TokenBalance[]> {
  console.log(`Getting token balances for wallet: ${walletAddress}\n`)

  const balances = await Promise.all(
    tokens.map(async (token) => {
      try {
        const balance = await client.readContract({
          address: token.address,
          abi: erc20Abi,
          functionName: 'balanceOf',
          args: [walletAddress],
        })

        const formattedBalance = formatUnits(balance, token.decimals)

        return {
          symbol: token.symbol,
          address: token.address,
          balance: formattedBalance,
          rawBalance: balance.toString(),
        }
      } catch (error) {
        return {
          symbol: token.symbol,
          address: token.address,
          balance: 'Error',
          error: error.message,
        }
      }
    }),
  )

  return balances
}

async function main(): Promise<void> {
  // Example wallet address (Vitalik's public address)
  const walletAddress: Address = '0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045'

  try {
    const balances = await getTokenBalances(walletAddress)

    console.log('Token Balances:')
    console.log('===============')

    balances.forEach((token) => {
      if (token.error) {
        console.log(`${token.symbol}: Error - ${token.error}`)
      } else {
        console.log(`${token.symbol}: ${token.balance}`)
      }
    })
  } catch (error) {
    console.error('Error fetching balances:', error)
  }
}

main().catch(console.error)