> ## Documentation Index
> Fetch the complete documentation index at: https://docs.hedera.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Call a smart contract function

The transaction calls a function of the given smart contract instance, giving it `functionParameters` as its input. The call can use at maximum the given amount of gas – the paying account will not be charged for any unspent gas.

If this function results in data being stored, an amount of gas is calculated that reflects this storage burden.

The amount of gas used, as well as other attributes of the transaction, e.g. size, and number of signatures to be verified, determine the fee for the transaction – which is charged to the paying account.

**Transaction Signing Requirements**

* The key of the transaction fee-paying account

**Transaction Fees**

* Please see the transaction and query [fees](/learn/networks/mainnet/fees#transaction-and-query-fees) table for the base transaction fee
* Please use the [Hedera fee estimator](https://hedera.com/fees) to estimate your transaction fee cost

<table><thead><tr><th>Method</th><th>Type</th><th>Description</th><th>Requirement</th></tr></thead><tbody><tr><td><code>setContractId(\<contractId>)</code></td><td>ContractID</td><td>The ID of the contract to call.</td><td>Required</td></tr><tr><td><code>setFunction(\<name, params>)</code></td><td>String, ContractFunctionParameters</td><td>Which function to call and the parameters to pass to the function.</td><td>Required</td></tr><tr><td><code>setGas(\<gas>)</code></td><td>long</td><td>The maximum amount of gas to use for the call.</td><td>Required</td></tr><tr><td><code>setPayableAmount(\<amount>)</code></td><td>Hbar</td><td>Number of HBARs sent (the function must be payable if this is nonzero)</td><td>Optional</td></tr></tbody></table>

<CodeGroup>
  ```java Java theme={null}
  //Create the transaction
  ContractExecuteTransaction transaction = new ContractExecuteTransaction()
       .setContractId(newContractId)
       .setGas(100_000_000)
       .setFunction("set_message", new ContractFunctionParameters()
            .addString("hello from hedera again!"));

  //Sign with the client operator private key to pay for the transaction and submit the query to a Hedera network
  TransactionResponse txResponse = transaction.execute(client);

  //Request the receipt of the transaction
  TransactionReceipt receipt = txResponse.getReceipt(client);

  //Get the transaction consensus status
  Status transactionStatus = receipt.status;

  System.out.println("The transaction consensus status is " +transactionStatus);

  //v2.0.0
  ```

  ```javascript JavaScript theme={null}
  //Create the transaction
  const transaction = new ContractExecuteTransaction()
       .setContractId(newContractId)
       .setGas(100_000_000)
       .setFunction("set_message", new ContractFunctionParameters()
            .addString("hello from hedera again!"));

  //Sign with the client operator private key to pay for the transaction and submit the query to a Hedera network
  const txResponse = await transaction.execute(client);

  //Request the receipt of the transaction
  const receipt = await txResponse.getReceipt(client);

  //Get the transaction consensus status
  const transactionStatus = receipt.status;

  console.log("The transaction consensus status is " +transactionStatus);

  //v2.0.0
  ```

  ```go Go theme={null}
  //Create the transaction
  transaction, err := hedera.NewContractExecuteTransaction().
       SetContractID(newContractID).
       SetGas(100000000).
       SetFunction("setMessage", contractFunctionParams)

  //Sign with the client operator private key to pay for the transaction and submit the query to a Hedera network
  txResponse, err := transaction.Execute(client)
  if err != nil {
  	panic(err)
  }

  //Request the receipt of the transaction
  receipt, err := txResponse.GetReceipt(client)
  if err != nil {
  	panic(err)
  }

  //Get the transaction consensus status
  transactionStatus := receipt.Status

  fmt.Printf("The transaction consensus status is %v\n", transactionStatus)

  //v2.0.0
  ```

  ```rust Rust theme={null}
  // Create the transaction
  let transaction = ContractExecuteTransaction::new()
      .contract_id(new_contract_id)
      .gas(100_000_000)
      .function("set_message", ContractFunctionParameters::new()
          .add_string("hello from hedera again!"));

  // Sign with the client operator private key to pay for the transaction and submit to a Hedera network
  let tx_response = transaction.execute(&client).await?;

  // Request the receipt of the transaction
  let receipt = tx_response.get_receipt(&client).await?;

  // Get the transaction consensus status
  let transaction_status = receipt.status;
  println!("The transaction consensus status is {:?}", transaction_status);

  // v0.34.0
  ```
</CodeGroup>