A fork of Base, in your tab

Real contracts, real state, a local copy. Send a swap, watch the block seal, then read every call it made.

Terminal · fork at block 00,000,000

Sim

A local fork of Base, made when you start. Nothing here is sent to Base.

No local blocks yet.

A copy of Base's state, forked at a recent block, running in this tab. Try one:

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Inspector · state, trace and code

Sim

Account: me ·
Fork: Not forked yet
Local head: —

Balances of me on the fork

Unit	Balance
ETH	—
USDC	—
WETH	—

Last receipt

No local transaction yet.

run aerodrome-swap · the app code behind it, checked on Base mainnet by verify-shell-recipes

aerodrome.ts

TS32 lines

1import { createPublicClient, createWalletClient, custom, erc20Abi, http, parseAbi, parseUnits } from 'viem'2import { base } from 'viem/chains'34const USDC = '0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913'5const WETH = '0x4200000000000000000000000000000000000006'6const ROUTER = '0xcF77a3Ba9A5CA399B7c97c74d54e5b1Beb874E43' // Aerodrome Router7const FACTORY = '0x420DD381b31aEf6683db6B902084cB0FFECe40Da' // Aerodrome classic pools8const routerAbi = parseAbi([9  'function getAmountsOut(uint256 amountIn, (address from, address to, bool stable, address factory)[] routes) view returns (uint256[] amounts)',10  'function swapExactTokensForTokens(uint256 amountIn, uint256 amountOutMin, (address from, address to, bool stable, address factory)[] routes, address to, uint256 deadline) returns (uint256[] amounts)',11])1213const wallet = createWalletClient({ chain: base, transport: custom(window.ethereum!) })14const client = createPublicClient({ chain: base, transport: http() })15const [account] = await wallet.requestAddresses()16const amountIn = parseUnits('1000', 6)17const routes = [{ from: USDC, to: WETH, stable: false, factory: FACTORY }] as const1819// Quote through the volatile USDC/WETH pool.20const amounts = await client.readContract({21  address: ROUTER, abi: routerAbi, functionName: 'getAmountsOut', args: [amountIn, routes],22})23const quoted = amounts[amounts.length - 1]2425// Let the router pull the USDC.26const approval = await wallet.writeContract({27  account, address: USDC, abi: erc20Abi, functionName: 'approve', args: [ROUTER, amountIn],28})29await client.waitForTransactionReceipt({ hash: approval })3031// Swap, accepting no less than 99.5% of the quote, within ten minutes.32const { timestamp } = await client.getBlock()33const swap = await wallet.writeContract({34  account, address: ROUTER, abi: routerAbi, functionName: 'swapExactTokensForTokens',35  args: [amountIn, quoted * 9950n / 10000n, routes, account, timestamp + 600n],36})37await client.waitForTransactionReceipt({ hash: swap })

This shell runs a copy of Base's state in your browser, forked at the block shown. Transactions you send here change only that copy. Nothing is signed, broadcast or paid for.