Across for Stablecoins

import { createWalletClient, createPublicClient, http } from "viem";
import { mainnet } from "viem/chains";
import { privateKeyToAccount } from "viem/accounts";

const account = privateKeyToAccount("0xYOUR_PRIVATE_KEY");
const walletClient = createWalletClient({ account, chain: mainnet, transport: http() });
const publicClient = createPublicClient({ chain: mainnet, transport: http() });

const params = new URLSearchParams({
  tradeType: "minOutput",
  originChainId: "1",
  destinationChainId: "42161",
  inputToken: "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48",   // USDC on Ethereum
  outputToken: "0xaf88d065e77c8cC2239327C5EDb3A432268e5831",   // USDC on Arbitrum
  amount: "1000000000",                                         // 1,000 USDC (6 decimals)
  depositor: account.address,
});

const quote = await fetch(
  `https://app.across.to/api/swap/approval?${params}`,
  { headers: { Authorization: "Bearer YOUR_API_KEY" } },
).then((r) => r.json());

// Execute approvals (if any), then the swap
if (quote.approvalTxns?.length) {
  for (const approvalTx of quote.approvalTxns) {
    const hash = await walletClient.sendTransaction({ to: approvalTx.to, data: approvalTx.data });
    await publicClient.waitForTransactionReceipt({ hash });
  }
}

const hash = await walletClient.sendTransaction({
  to: quote.swapTx.to,
  data: quote.swapTx.data,
  value: quote.swapTx.value ? BigInt(quote.swapTx.value) : 0n,
});

console.log("Transfer tx:", hash);