# Build a postHook

After the swap or bridge is executed, the resulting tokens will be left on the Squid Multicall contract. From there the `postHook` calls will be executed.

{% tabs %}
{% tab title="SDK" %}
Create contract interfaces for the posthook

```typescript
// Creating Contract interfaces
// Approve the lending contract to spend the erc20
const erc20Interface = new ethers.utils.Interface(erc20Abi);
const approvalerc20 = erc20Interface.encodeFunctionData("approve", [
  radiantLendingPoolAddress,
  ethers.constants.MaxUint256,
]);

// Create contract interface and encode deposit function for Radiant lending pool
const radiantLendingPoolInterface = new ethers.utils.Interface(
  radiantLendingPoolAbi
);
const depositEncodedData = radiantLendingPoolInterface.encodeFunctionData(
  "deposit",
  [
    usdcArbitrumAddress,
    "0", // Placeholder for dynamic balance
    signer.address,
    0,
  ]
);
```

Create postHook 

```typescript

// Set up parameters for swapping tokens and depositing into Radiant lending pool
const params = {
  fromAddress: signer.address,
  fromChain: fromChainId,
  fromToken: fromToken,
  fromAmount: amount,
  toChain: toChainId,
  toToken: usdcArbitrumAddress,
  toAddress: signer.address,
  slippage: 1,
  quoteOnly: false,
  enableBoost: true,
  slippage: 1, //OPTIONAL to set slippage, it will be set dynamically if not included
  postHook: {
    chainType: ChainType.EVM,
    calls: [
      {
        chainType: ChainType.EVM, 
        callType: 1,// SquidCallType.FULL_TOKEN_BALANCE
        target: usdcArbitrumAddress,
        value: "0", // this will be replaced by the full native balance of the multicall after the swap
        callData: approvalerc20,
        payload: {
          tokenAddress: usdcArbitrumAddress,
          inputPos: 1,
        },
        estimatedGas: "50000",
      },
      {
        chainType: ChainType.EVM,
        callType: 1, // SquidCallType.FULL_TOKEN_BALANCE
        target: radiantLendingPoolAddress,
        value: "0",
        callData: depositEncodedData,
        payload: {
          tokenAddress: usdcArbitrumAddress,
          inputPos: 1,
        },
        estimatedGas: "50000",
      },
    ],
    provider: "Integration Test", //This should be the name of your product or application that is triggering the hook
    description: "Wrap native ETH",
    logoURI: "https://pbs.twimg.com/profile_images/1548647667135291394/W2WOtKUq_400x400.jpg", //Add your logo here
  },
};

```

{% endtab %}

{% tab title="API" %}
Import the ABIs and create the contract interface

```typescript
// Import Radiant lending pool ABI
import radiantLendingPoolAbi from "../abi/radiantLendingPoolAbi";

// Import erc20 contract ABI
import erc20Abi from "../abi/erc20Abi";

// Set up JSON RPC provider and signer 
const provider = new ethers.providers.JsonRpcProvider(FROM_CHAIN_RPC);
const signer = new ethers.Wallet(privateKey, provider);



// Creating Contract interfaces

// Approve the lending contract to spend the erc20
const erc20Interface = new ethers.utils.Interface(erc20Abi);
const approvalerc20 = erc20Interface.encodeFunctionData("approve", [
  radiantLendingPoolAddress,
  ethers.constants.MaxUint256,
]);

// Create contract interface and encode deposit function for Radiant lending pool
const radiantLendingPoolInterface = new ethers.utils.Interface(
  radiantLendingPoolAbi
);
const depositEncodedData = radiantLendingPoolInterface.encodeFunctionData(
  "deposit",
  [
    usdcArbitrumAddress,
    "0", // Placeholder for dynamic balance
    signer.address,
    0,
  ]
);
```

Build the parameters to including the postHook

<pre class="language-typescript"><code class="lang-typescript"><strong>
</strong><strong>params = {
</strong>    fromAddress: signer.address,
    fromChain: fromChainId,
    fromToken: fromToken,
    fromAmount: amount,
    toChain: toChainId,
    toToken: usdcArbitrumAddress,
    toAddress: signer.address,
    slippage: 1,
    slippageConfig: {
      autoMode: 1,
    },
    postHook: {
      chainType: "evm",
      //fundAmount: amount,  //only required for prehooks
      //fundToken: usdcArbitrumAddress, //only required for prehooks
      calls: [
        {
          callType: 1,
          target: usdcArbitrumAddress,
          value: "0", // this will be replaced by the full native balance of the multicall after the swap
          callData: approvalerc20,
          payload: {
            tokenAddress: usdcArbitrumAddress, // unused in callType 2, dummy value
            inputPos: "1", // unused
          },
          estimatedGas: "50000",
          chainType: "evm",
        },
        {
          callType: 1, // SquidCallType.FULL_TOKEN_BALANCE
          target: radiantLendingPoolAddress,
          value: "0",
          callData: depositEncodedData,
          payload: {
            tokenAddress: usdcArbitrumAddress,
            inputPos: "1",
          },
          estimatedGas: "50000",
          chainType: "evm",
        },
      ],
      description: "",
      
    },
  };

</code></pre>

{% endtab %}
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