ERC20 (erc20)

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What it offers

• transfer: Send tokens to an address
• approve: Authorize a spender to transfer tokens on your behalf
• transferFrom: Transfer tokens from one address to another (requires approval)
• balanceOf: Query token balance of an address
• allowance: Query remaining approved amount for a spender

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Notes

• Standard interface (EIP-20) - not a specific deployment, no fixed addresses
• Every fungible token on every EVM chain implements this interface
• approve before transferFrom: spender must be approved by the owner first
• Common pattern: approve max (type(uint256).max) for DeFi interactions, or use exact amounts for security
• decimals varies: most tokens use 18, USDC/USDT use 6, WBTC uses 8
• Some tokens (USDT) do not return bool from transfer/approve. The writes above are @sauce/token’s, which follow OpenZeppelin SafeERC20: empty returndata is accepted from a contract, a false return reverts, and approve resets a non-zero allowance to zero first. They return nothing, since a refused write reverts the program
• ERC20ABI.at(token).transfer(...) is the raw ABI call and is NOT SafeERC20: it reverts on a token that returns nothing and accepts one that returns false. Use it only when that is what you mean
• The storageTransfer example demonstrates how to implement ERC-20 logic entirely in SauceScript using storage operations

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Its names in a program

import ERC20ABI from "./protocols/erc20/ERC20ABI.json";

// The contract's address, a `main` argument.
function main(contract: Address) {
  const target = ERC20ABI.at(contract);
}

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ABI

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ERC20ABI

• transfer(address to, uint256 amount) returns (bool)
• approve(address spender, uint256 amount) returns (bool)
• transferFrom(address from, address to, uint256 amount) returns (bool)
• balanceOf(address account) view returns (uint256)
• allowance(address owner, address spender) view returns (uint256)
• totalSupply() view returns (uint256)
• name() view returns (string)
• symbol() view returns (string)
• decimals() view returns (uint8)

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Next steps

• Protocols: the other protocols, by what they do.
• Protocols and tokens: calling a contract by its namespace, or through its ABI.
• Glossary: the words these pages use, in plain terms.