Overview
Utilities for encoding ERC-20 token function calls and decoding responses. Supports balance queries, transfers, and approvals.
Functions
encodeErc20BalanceOf
Encodes calldata for the ERC-20 balanceOf() function.
function encodeErc20BalanceOf(owner: Address): Hex
The address to check the balance for
Encoded calldata for balanceOf(address)
import { encodeErc20BalanceOf } from "@/lib/protocols/erc20";
const calldata = encodeErc20BalanceOf("0x742d35Cc6634C0532925a3b844Bc9e7595f0bEb");
// Use with eth_call to query token balance
decodeErc20BalanceOf
Decodes the result of an ERC-20 balanceOf() call.
function decodeErc20BalanceOf(result: Hex): bigint
The raw result from eth_call
The token balance in smallest unit
import { decodeErc20BalanceOf } from "@/lib/protocols/erc20";
const balance = decodeErc20BalanceOf("0x0000000000000000000000000000000000000000000000000de0b6b3a7640000");
// Returns: 1000000000000000000n (1 token with 18 decimals)
encodeErc20Transfer
Encodes calldata for the ERC-20 transfer() function.
function encodeErc20Transfer(to: Address, amount: bigint): Hex
The amount to transfer (in token’s smallest unit)
Encoded calldata for transfer(address,uint256)
import { encodeErc20Transfer } from "@/lib/protocols/erc20";
const transferCalldata = encodeErc20Transfer(
"0x742d35Cc6634C0532925a3b844Bc9e7595f0bEb",
1000000n // Transfer 1 USDC (6 decimals)
);
encodeErc20Approve
Encodes calldata for the ERC-20 approve() function.
function encodeErc20Approve(spender: Address, amount: bigint): Hex
The address authorized to spend tokens
The allowance amount (in token’s smallest unit)
Encoded calldata for approve(address,uint256)
import { encodeErc20Approve } from "@/lib/protocols/erc20";
// Approve Aave Pool to spend USDC
const approveCalldata = encodeErc20Approve(
"0x87870Bca3F3fD6335C3F4ce8392D69350B4fA4E2", // Aave Pool
1000000n // Approve 1 USDC
);
Usage Example
Complete workflow for checking balance and transferring tokens:
import {
encodeErc20BalanceOf,
decodeErc20BalanceOf,
encodeErc20Transfer
} from "@/lib/protocols/erc20";
// 1. Check balance
const balanceCalldata = encodeErc20BalanceOf(walletAddress);
const balanceResult = await provider.request({
method: "eth_call",
params: [
{
to: tokenAddress,
data: balanceCalldata
},
"latest"
]
});
const balance = decodeErc20BalanceOf(balanceResult as Hex);
// 2. Transfer tokens
const transferCalldata = encodeErc20Transfer(recipientAddress, balance);
// Use with Kernel execution or direct transaction
Type Definitions
Address
type Address = `0x${string}`;
0x.
Hex
type Hex = `0x${string}`;
0x.