# Call Contract Example

{% embed url="<https://youtu.be/jXAaIAA2tz4>" %}

## Parameters

* `contractAddress` - `string` Contract address to interact with
* `functionName` - `string` Smart contract function to interact with
* `abi` - `Array<AbiItem>` (Optional) ABI of the contract to call
* `params` - `Array<string>` (Optional) Params to call the smart contract function with
* `valueInWei` - `string` (Optional) Amount of wei to send
* `gasLimit` - `string` (Optional) Gas limit for the function call
* `chain` - `Object` used to ensure the user is on the correct chain (follows the [MetaMask specification](https://docs.metamask.io/guide/rpc-api.html#unrestricted-methods))
  * `chainId` - `string` Base 10 string matching the chain id on [Chainlist](https://chainlist.org/)
  * `chainMetadata` (Optional) - `Object` used to add the chain if the user does not have the chain added to their wallet
    * `chainName` - `string`&#x20;
    * `nativeCurrency` - `Object`
      * `name` - `string` is the currency's name
      * `symbol` - `string` 2-6 characters long symbol for the chain
      * `decimals` - `18`
    * `rpcUrls` - `Array<string>` is an array of rpc node urls that can be used to make requests. We recommend selecting a few from the listing on [Chainlist](https://chainlist.org/)
    * `blockExplorerUrls` (Optional) - `Array<string>` is an array of block explorers that can be used with the chain
    * `iconUrls` (Optional) - `Array<string>` is currently unused by MetaMask

## Request

This request reads the name of a contract.

{% tabs %}
{% tab title="curl" %}

```bash
curl --location --request POST "localhost:9680/callContract" \
--header 'Content-Type: application/json' \
--data-raw '{
    "contractAddress": "0xdac17f958d2ee523a2206206994597c13d831ec7",
    "functionName": "totalSupply",
    "params": [],
    "abi": [
      {
        "inputs": [],
        "name": "totalSupply",
        "outputs": [
          {
            "internalType": "uint256",
            "name": "",
            "type": "uint256"
          }
        ],
        "stateMutability": "view",
        "type": "function"
      }
    ],
    "chain": { "chainId": "1", "chainMetadata": { "chainName": "Ethereum", "nativeCurrency": { "name": "ETH", "symbol": "ETH", "decimals": 18 }, "rpcUrls": ["https://rpc.ankr.com/eth"] } }
}'

```

{% endtab %}

{% tab title="Unity" %}

```csharp
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Networking;

public class CallContract : MonoBehaviour
{
    void Start()
    {
        StartCoroutine(Call()); 
    }

    private IEnumerator Call()
    {
        string jsonString = "{ \"contractAddress\": \"0xa0b86991c6218b36c1d19d4a2e9eb0ce3606eb48\", \"functionName\": \"totalSupply\", \"params\": [], \"abi\": [ { \"inputs\": [], \"name\": \"totalSupply\", \"outputs\": [ { \"internalType\": \"uint256\", \"name\": \"\", \"type\": \"uint256\" } ], \"stateMutability\": \"view\", \"type\": \"function\" } ], \"chain\": { \"chainId\": \"1\", \"chainMetadata\": { \"chainName\": \"Ethereum\", \"nativeCurrency\": { \"name\": \"ETH\", \"symbol\": \"ETH\", \"decimals\": 18 }, \"rpcUrls\": [\"https://rpc.ankr.com/eth\"] } } }";
        byte[] jsonBytes = System.Text.Encoding.UTF8.GetBytes(jsonString);

        UnityWebRequest request = new UnityWebRequest("localhost:9680/callContract", "POST");
        request.uploadHandler = new UploadHandlerRaw(jsonBytes);
        request.downloadHandler = new DownloadHandlerBuffer();
        request.SetRequestHeader("Content-Type", "application/json");

        yield return request.SendWebRequest();
        Debug.Log(request.error);
        string totalSupply = request.downloadHandler.text;
        Debug.Log(totalSupply);
    }
}

```

{% endtab %}

{% tab title="Unreal Engine C++" %}

```cpp
#include "HyperPlayUtils.h"
#include "Endpoints/SendContract.h"

void OnResponse(FString Response, int32 StatusCode)
{
	const bool bWasSuccessful = HyperPlayUtils::StatusCodeIsSuccess(StatusCode);

	UE_LOG(LogTemp, Display, TEXT("CallContract Success: %s"), bWasSuccessful ? "true" : "false");
	UE_LOG(LogTemp, Display, TEXT("CallContract Response: %s"), *Response);
}

int main(){
  UCallContract* GetAccountsInstance = UCallContract::CallContract(nullptr,
    "0xBA62BCfcAaFc6622853cca2BE6Ac7d845BC0f2Dc",
    "name",
    "",
    {},
    -1,
    "",
    5);
  GetAccountsInstance->GetOnCompletedDelegate().AddRaw(this, &OnResponse);
  GetAccountsInstance->Activate();
}
```

{% endtab %}
{% endtabs %}

## Response

The response value(s) of the smart contract method are mixed. If it returns a single value, it’s returned as is. If it has multiple return values they are returned as an object with properties and indices:&#x20;

{% tabs %}
{% tab title="Response" %}

```
"FaucetToken"
```

{% endtab %}

{% tab title="Error" %}
Errors will have an HTTP response status 500-599

```json
{
  "message": "error description here"
}
```

{% endtab %}
{% endtabs %}


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.hyperplay.xyz/developer-docs/api/call-contract-example.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.