Multicall

Batch multiple contract reads into a single RPC call using Multicall3 on Sei

Multicall

Multicall3 lets you batch multiple read calls into a single RPC round-trip, dramatically reducing latency for dashboards, portfolio pages, and any view that needs data from multiple contracts at once.

Multicall3 is deployed at 0xcA11bde05977b3631167028862bE2a173976CA11 on Sei mainnet and testnet — the same address as Ethereum.

Batching ERC-20 Reads with viem

viem’s multicall action wraps Multicall3 automatically:

import { createPublicClient, http, parseAbi } from 'viem';
import { sei } from '@sei-js/precompiles/viem';

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

const ERC20_ABI = parseAbi([
  'function balanceOf(address owner) view returns (uint256)',
  'function symbol() view returns (string)',
  'function decimals() view returns (uint8)',
]);

const tokens = [
  '0xTokenA',
  '0xTokenB',
  '0xTokenC',
] as const;

const owner = '0xYourAddress';

// Fetch symbol, decimals, and balance for every token in one call
const results = await client.multicall({
  contracts: tokens.flatMap((address) => [
    { address, abi: ERC20_ABI, functionName: 'symbol' },
    { address, abi: ERC20_ABI, functionName: 'decimals' },
    { address, abi: ERC20_ABI, functionName: 'balanceOf', args: [owner] },
  ]),
});

// Results are returned in the same order as the input contracts array
// Each result has { status: 'success' | 'failure', result, error }
tokens.forEach((address, i) => {
  const symbol  = results[i * 3];
  const decimals = results[i * 3 + 1];
  const balance  = results[i * 3 + 2];

  if (symbol.status === 'success' && balance.status === 'success') {
    console.log(`${address}: ${balance.result} (${symbol.result})`);
  }
});

Allowing Individual Call Failures

By default, a single failed call causes the entire batch to revert. Use allowFailure: true (the default in viem) to get partial results instead:

const results = await client.multicall({
  contracts: [
    { address: '0xTokenA', abi: ERC20_ABI, functionName: 'balanceOf', args: [owner] },
    { address: '0xMaybeInvalid', abi: ERC20_ABI, functionName: 'balanceOf', args: [owner] },
  ],
  allowFailure: true, // default — individual failures don't abort the batch
});

results.forEach((result) => {
  if (result.status === 'success') {
    console.log('Balance:', result.result);
  } else {
    console.warn('Call failed:', result.error);
  }
});

Batching with ethers

ethers doesn’t have a built-in multicall action, but you can call the Multicall3 contract directly:

import { ethers } from 'ethers';

const provider = new ethers.JsonRpcProvider('https://evm-rpc.sei-apis.com');

const MULTICALL3_ADDRESS = '0xcA11bde05977b3631167028862bE2a173976CA11';
const MULTICALL3_ABI = [
  'function aggregate3(tuple(address target, bool allowFailure, bytes callData)[] calls) view returns (tuple(bool success, bytes returnData)[] returnData)',
];

const multicall = new ethers.Contract(MULTICALL3_ADDRESS, MULTICALL3_ABI, provider);

const ERC20_INTERFACE = new ethers.Interface([
  'function balanceOf(address owner) view returns (uint256)',
]);

const owner = '0xYourAddress';
const tokens = ['0xTokenA', '0xTokenB', '0xTokenC'];

const calls = tokens.map((target) => ({
  target,
  allowFailure: true,
  callData: ERC20_INTERFACE.encodeFunctionData('balanceOf', [owner]),
}));

const results = await multicall.aggregate3(calls);

results.forEach(({ success, returnData }: { success: boolean; returnData: string }, i: number) => {
  if (success) {
    const [balance] = ERC20_INTERFACE.decodeFunctionResult('balanceOf', returnData);
    console.log(`${tokens[i]}: ${balance}`);
  }
});

Wagmi

In React apps, useReadContracts handles batching automatically:

import { useReadContracts } from 'wagmi';
import { parseAbi } from 'viem';

const ERC20_ABI = parseAbi([
  'function balanceOf(address owner) view returns (uint256)',
  'function symbol() view returns (string)',
]);

const TOKEN_A = '0xTokenA' as const;
const TOKEN_B = '0xTokenB' as const;
const owner   = '0xYourAddress' as const;

export function MultiTokenBalances() {
  const { data } = useReadContracts({
    contracts: [
      { address: TOKEN_A, abi: ERC20_ABI, functionName: 'symbol' },
      { address: TOKEN_A, abi: ERC20_ABI, functionName: 'balanceOf', args: [owner] },
      { address: TOKEN_B, abi: ERC20_ABI, functionName: 'symbol' },
      { address: TOKEN_B, abi: ERC20_ABI, functionName: 'balanceOf', args: [owner] },
    ],
  });

  if (!data) return null;

  return (
    <ul>
      <li>{data[0].result}: {data[1].result?.toString()}</li>
      <li>{data[2].result}: {data[3].result?.toString()}</li>
    </ul>
  );
}