Integrate

import { createPublicClient, createWalletClient, erc20Abi, http, parseEther } from "viem";
import { privateKeyToAccount } from "viem/accounts";
import { base } from "viem/chains";
import { BondingCurveAbi, LaunchpadFactoryAbi } from "./abi"; // the app's own ABI files, apps/web/src/abi

// the two addresses to fill in: the Factory from the list above, and the coin's token address
const FACTORY = "0x…" as const;
const TOKEN = "0x…" as const;

const account = privateKeyToAccount(process.env.KEY as `0x${string}`);
const pub = createPublicClient({ chain: base, transport: http(process.env.RPC) });
const wallet = createWalletClient({ account, chain: base, transport: http(process.env.RPC) });

// 1. the coin's curve: the factory knows it by the token's address
const { curve } = await pub.readContract({ address: FACTORY, abi: LaunchpadFactoryAbi, functionName: "launches", args: [TOKEN] });

// 2. a buy: quote it, keep a minimum, name who gets the coins (and the spin)
const ethIn = parseEther("0.05");
const [tokensOut] = await pub.readContract({ address: curve, abi: BondingCurveAbi, functionName: "quoteBuy", args: [ethIn] });
await wallet.writeContract({
  address: curve, abi: BondingCurveAbi, functionName: "buy",
  args: [(tokensOut * 99n) / 100n, account.address], // minTokensOut (1 % slippage), recipient
  value: ethIn,
});

// 3. a sell: quote it, keep a minimum, approve exactly what you sell, then sell; a sell never spins
const amount = parseEther("1000"); // coins to sell, in wei of the token
const [ethOut] = await pub.readContract({ address: curve, abi: BondingCurveAbi, functionName: "quoteSell", args: [amount] });
await wallet.writeContract({ address: TOKEN, abi: erc20Abi, functionName: "approve", args: [curve, amount] });
await wallet.writeContract({
  address: curve, abi: BondingCurveAbi, functionName: "sell",
  args: [amount, (ethOut * 99n) / 100n, account.address], // tokensIn, minEthOut (1 % slippage), recipient
});