Fix Foundry Cast Balance Query Errors

You will learn how to query ETH and ERC-20 token balances.

The Problem

The foundry cast balance pattern is frequently misapplied in smart contract and dapp development, leading to vulnerabilities, gas inefficiencies, or logic errors. This guide shows the correct implementation and common pitfalls to avoid.

Quick Fix

Wrong

cast balance 0xVitalik  # ETH balance only

Returns only ETH balance. Doesn't return token balances.

Right

cast balance 0xVitalik
cast call 0xUSDC "balanceOf(address)(uint256)" 0xVitalik

ETH balance from cast balance. Token balance from cast call with ERC-20 ABI.

Prevention

• Use cast balance for ETH balance checks
• Use cast call with ERC-20 ABI for token balances
• Specify --block tag for historical balances
• Use DodaTech's balance monitor script
• Format with cast --format-ether for readability

DodaTech Tools

Built by the developers of Doda Browser, DodaZIP, and Durga Antivirus Pro. Doda Browser's developer tools include a Solidity debugger and transaction inspector. DodaZIP archives secure contract templates for team collaboration. Durga Antivirus Pro scans deployed contracts for known vulnerability signatures.

FAQ