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Batch token approvals with Swaps transactions

On EVM chains, you will need to grant token approvals to submit transactions. The spender in the approval should be the to address in the transaction object returned by the /getAction endpoint. Recent EIPs enable applications to batch the approval and Swaps transactions. This means EVM ERC20 transactions are still only a single transaction for your users. We recommend the wallet_sendCalls method enabled by EIP 5792. The example below generates a cross-chain swap for 10 USDC on Base to USDT on Arbitrum. It demonstrates how to call the /getAction endpoint and batch the returned transaction with an approval for 10 USDC on Base so that both the approval and swap can be submitted in a single transaction. Refer to the [EVM Broadcast Guide] 
  import { getAction } from "./getAction";
  import { parseAbiItem } from "viem";
  import { walletClient } from "./config";

  const actionRequest: ActionRequest = {
    actionType: "swap-action",
    sender: "0xd8da6bf26964af9d7eed9e03e53415d37aa96045", // generally the user's connected wallet address
    srcToken: "0x833589fcd6edb6e08f4c7c32d4f71b54bda02913", // USDC on Base
    dstToken: "0xfd086bc7cd5c481dcc9c85ebe478a1c0b69fcbb9", // USDT on Arbitrum
    srcChainId: 8453, // Base Chain ID
    dstChainId: 42161, // Arbitrum Chain ID
    slippage: 100, // bps
    swapDirection: "exact-amount-in",
    amount: 10000000n, // denominated in srcToken decimals
    recipient: "0xd8da6bf26964af9d7eed9e03e53415d37aa96045",
  };

  const tx = await getAction({ actionRequest });

  export async function sendBatchedTx() {
    const { id } = await walletClient.sendCalls([
      calls: [
        {
          to: actionRequest.srcToken,
          abi: parseAbiItem('function approve(address, uint256) returns (bool)'),
          functionName: 'approve',
          args: [
            tx.to,
            amount
          ]
        },
        {
          to: tx.to,
          value: tx.value,
          data: tx.data
        },
      ]
    ]);

    return id;
  }
Alternatively, you like to use EIP-7702, which enables EOAs to designate a smart contract as its implementation. This EIP equips EOAs with features previously reserved for smart contract accounts like transaction batching, sponsorship, and delegated signing. We find EIP 5792 to be a lighter-weight implementation for batching transactions specifically. For a basic example of the sequenced, legacy approval method, please visit this NFT mint button example.