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API Reference: Get Action This guide will only cover the process of generating calldata transactions. You can submit this transaction exactly as outlined in the swap broadcast flows.

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Create a cross-chain transaction

In this example, we are going to deposit 1 ETH liquidity in Aave on Base using USDC on Arbitrum.
1

Build your destination transaction.

We’ll use helper functions from Viem; however, you can use your preferred library.
import { account, walletClient } from "./your_viem_config";
import { encodeFunctionData, parseAbiItem, Hex } from "viem";

const aaveOnBase = "0xA238Dd80C259a72e81d7e4664a9801593F98d1c5";
const ethDepositAmount = 1000000000000000000n;
const sender = "0xd8da6bf26964af9d7eed9e03e53415d37aa96045"; // generally the user's connected wallet address

const supplyTxCalldata: Hex = encodeFunctionData({
  abi: parseAbiItem(
    "function supply(address asset, uint256 amount, address onBehalfOf, uint16 referralCode)"
  ),
  functionName: "supply",
  args: [
    "0x0000000000000000000000000000000000000000",
    ethDepositAmount,
    sender,
    0n,
  ],
});
2

Configure the transaction request

Cross-chain calls can handle all non-permissioned functions. If your function includes a msg.sender check, please consider updating it to a multi-chain compatible sender authentication method based on this guide.
Calldata Transaction Config
const txConfig: ActionRequest = {
  actionType: "evm-calldata-tx",
  sender,
  srcToken: "0xaf88d065e77c8cc2239327c5edb3a432268e5831", // USDC on Arbitrum
  dstToken: "0x0000000000000000000000000000000000000000", // ETH on Base
  srcChainId: 42161, // Arbitrum Chain ID
  dstChainId: 8453, // Base Chain ID
  slippage: 100, // bps
  to: aaveOnBase,
  data: supplyTxCalldata,
  value: ethDepositAmount,
};
3

Generate the transaction

Please visit the Get Action API reference for type definitions, including the ActionRequest and ActionResponse. This API endpoint will return a transaction object we will use to actually execute this transaction.
async function getAction({ actionRequest }): Promise<ActionResponse> {
  const url = new URL("https://api-v2.swaps.xyz/api/getAction");

  Object.entries(actionRequest).forEach(([key, value]) => {
    url.searchParams.set(key, String(value));
  }

  const requestOptions = {
    method: "GET",
    headers: { "x-api-key": SWAPS_API_KEY },
  };

  const response = await fetch(url.toString(), requestOptions);

  return await response.json();
}
That’s it! You now have a transaction you can broadcast on your source chain. Please see the swap broadcast flows for how you can send this transaction on chain.