Smart Contract Client¶

SmartContractClient provides APIs for managing smart contracts on a Hiero network, including contract deployment and function execution.

Note

Smart contract operations that submit transactions to the Hiero network require HBAR to pay transaction fees. The configured operator account is used as the transaction payer and must have sufficient HBAR balance.

Methods¶

Method	Description
`createContract(String fileId, ContractParam<?>... constructorParams)`	Creates a smart contract using bytecode stored in a file ID string.
`createContract(FileId fileId, ContractParam<?>... constructorParams)`	Creates a smart contract using an existing bytecode file.
`createContract(byte[] contents, ContractParam<?>... constructorParams)`	Creates a smart contract using bytecode contents.
`createContract(Path pathToBin, ContractParam<?>... constructorParams)`	Creates a smart contract using a bytecode file path.
`callContractFunction(String contractId, String functionName, ContractParam<?>... params)`	Executes a contract function using a contract ID string.
`callContractFunction(ContractId contractId, String functionName, ContractParam<?>... params)`	Executes a contract function using a contract ID.

Create Contract¶

Deploys a smart contract to the Hiero network.

createContract(FileId fileId, ContractParam<?>... constructorParams)

FileId fileId =
    FileId.fromString("0.0.1234");


ContractId contractId =
    smartContractClient.createContract(
        fileId,
        ContractParam.string("Hello Hiero")
    );

createContract(byte[] contents, ContractParam<?>... constructorParams)

byte[] bytecode =
    Files.readAllBytes(
        Path.of("contract.bin")
    );

ContractId contractId =
    smartContractClient.createContract(
        bytecode,
        ContractParam.string("Hello Hiero")
    );

createContract(Path pathToBin, ContractParam<?>... constructorParams)

ContractId contractId =
    smartContractClient.createContract(
        Path.of("contract.bin"),
        ContractParam.string("Hello Hiero")
    );

Call Contract Function¶

Executes a function on an existing smart contract.

callContractFunction(ContractId contractId, String functionName, ContractParam<?>... params)

ContractId contractId =
    ContractId.fromString("0.0.5678");

ContractCallResult result =
    smartContractClient.callContractFunction(
        contractId,
        "getValue",
        ContractParam.string("Hello Hiero")
    );

Tip

See the Contract Parameters documentation for all supported Solidity parameter types, including strings, addresses, booleans, bytes, and numeric types.