Gas Optimization
for AI Agents

import { ethers } from 'ethers';

const provider = new ethers.JsonRpcProvider('https://mainnet.infura.io/v3/YOUR_KEY');

// Fetch current EIP-1559 fee data
const feeData = await provider.getFeeData();

const baseFee       = feeData.lastBaseFeePerGas;   // current block baseFee
const maxPriorityFee = ethers.parseUnits('0.5', 'gwei'); // tip: 0.5 gwei

// maxFeePerGas = 2x baseFee (buffer for next-block increase) + tip
const maxFee = baseFee * 2n + maxPriorityFee;

// Only proceed if gas is below threshold (10 gwei baseFee)
const GAS_THRESHOLD = ethers.parseUnits('10', 'gwei');
if (baseFee > GAS_THRESHOLD) {
  console.log('Gas too high, queuing for later...');
  return;
}

const tx = await wallet.sendTransaction({
  to:                  contractAddress,
  data:                calldata,
  maxFeePerGas:        maxFee,
  maxPriorityFeePerGas:maxPriorityFee,
});

async function estimateWithBuffer(contract, method, args) {
  const rawEstimate = await contract[method].estimateGas(...args);

  // Add 20% buffer to avoid out-of-gas failures
  return (rawEstimate * 120n) / 100n;
}

// Example: Uniswap V3 exactInputSingle swap
const swapParams = {
  tokenIn:           WETH_ADDRESS,
  tokenOut:          USDC_ADDRESS,
  fee:               3000,
  recipient:         wallet.address,
  amountIn:          ethers.parseEther('0.1'),
  amountOutMinimum:  0n,
  sqrtPriceLimitX96: 0n,
};

const gasLimit = await estimateWithBuffer(
  swapRouter,
  'exactInputSingle',
  [swapParams]
);

const receipt = await swapRouter.exactInputSingle(swapParams, { gasLimit });
console.log(`Gas used: ${receipt.gasUsed} / ${gasLimit}`);

// Multicall3 is deployed at the same address on all major EVM chains
const MULTICALL3 = '0xcA11bde05977b3631167028862bE2a173976CA11';

const multicall = new ethers.Contract(MULTICALL3, [
  'function aggregate3(tuple(address target, bool allowFailure, bytes callData)[] calls) payable returns (tuple(bool success, bytes returnData)[])'
], wallet);

// Build calls for 3 separate ERC-20 transfers
const iface = new ethers.Interface([
  'function transfer(address to, uint256 amount) returns (bool)'
]);

const calls = recipients.map(({ address, amount }) => ({
  target:       TOKEN_ADDRESS,
  allowFailure: false,
  callData:     iface.encodeFunctionData('transfer', [address, amount]),
}));

// One transaction instead of three — one base fee, lower total gas
const results = await multicall.aggregate3(calls);

// No wallet. No gas estimation. No RPC node. Just an API call.
const result = await fetch('https://api.purpleflea.com/v1/swap', {
  method:  'POST',
  headers: {
    'Authorization': `Bearer ${PURPLEFLEA_API_KEY}`,
    'Content-Type':  'application/json',
  },
  body: JSON.stringify({
    fromToken: 'ETH',
    toToken:   'USDC',
    amount:    '0.1',
    chain:     'base',      // Purple Flea routes to cheapest execution
    slippage:  0.5,
  }),
}).then(r => r.json());

// You receive: { status: 'confirmed', txHash: '0x...', usdFee: 0.12 }
// Purple Flea paid the gas. You pay a flat USD fee.
console.log(result.status); // 'confirmed'