Update a smart contract

A transaction that allows you to modify the smart contract entity state like admin keys, proxy account, auto-renew period, and memo. This transaction does not update the contract that is tied to the smart contract entity. The contract tied to the entity is immutable. The contract entity is immutable if an admin key is not specified. Once the transaction has been successfully executed on a Hedera network the previous field values will be updated with the new ones. To get a previous state of a smart contract instance, you can query a mirror node for that data. Any null field is ignored (left unchanged)

Transaction Signing Requirements

• If only the expiration time is being modified, then no signature is needed on this transaction other than for the account paying for the transaction itself.

• If any other smart contract entity property is being modified, the transaction must be signed by the admin key.

• If the admin key is being updated, the new key must sign

Transaction Fees

• Please see the transaction and query fees table for the base transaction fee

• Please use the Hedera fee estimator to estimate your transaction fee cost

Smart Contract Properties

Field	Description
Admin Key	Sets the new admin key and its fields can be modified arbitrarily if this key signs a transaction to modify it. If this is null, then such modifications are not possible, and there is no administrator that can override the normal operation of this smart contract instance. Note that if it is created with no admin keys, then there is no administrator to authorize changing the admin keys, so there can never be any admin keys for that instance. The bytecode will also be immutable.
Expiration Time	The new expiry of the contract, no earlier than the current expiry (resolves to EXPIRATION_REDUCTION_NOT_ALLOWED otherwise).
Staked ID	The new node account ID or node ID this contract is being staked to. If set to the sentinel 1, this removes the contract's staked node ID. See HIP-406. Note: Accounts cannot stake to contract accounts. This will fixed in a future release.
Decline Rewards	Updates the contract to decline receiving staking rewards if set to true. The default value is false. See HIP-406.
Auto Renew Period	The new period that the instance will charge its account every this many seconds to renew.
Auto Renew Account ID	Indicates the account that will pay the contract's auto-renew fee. If the Auto Renew account id is cleared, then the smart contract's account will be charged the auto-renew fee
Automatic Token Associations	The maximum number of tokens that this contract can be automatically associated with (i.e., receive air-drops from).
Memo	The new memo to be associated with this contract.

Methods

Method	Type	Requirement
setContractId(<contractId>)	ContractId	Required
setAdminKey(<keys>)	Key	Optional
setContractMemo(<memo>)	String	Optional
setExpirationTime(<expirationTime)	Instant	Optional
setMaxAutomaticTokenAssociations()	int	Optional
setContractMemo(<memo>)	String	Optional
setStakedAccountId(<stakedAccountId>)	AccountId	Optional
setStakedNodeId(<stakedNodeId>)	long	Optional
setDeclineStakingReward(<declineStakingReward>)	boolean	Optional
setAutoRenewPeriod(<autoRenewPeriod>)	Duration	Optional
setAutoRenewAccountId(<accountId>)	AccountId	Optional
clearAutoRenewAccountId()		Optional

Note: The new expiration time must be an instance of type Timestamp, thus, the Timestamp object has to be imported from the SDK package. The new expiration time has to be initialized as a new instance of that type.

Java

//Create the transaction 
ContractUpdateTransaction transaction = new ContractUpdateTransaction()
    .setContractId(contractId)
    .setAdminKey(adminKey);

//Modify the default transaction fee
ContractUpdateTransaction modifyTransactionFee = transaction.setMaxTransactionFee(new Hbar(20));

//sign with the new admin key, sign with the old admin key, sign with the client operator account and submit to a Hedera network
TransactionResponse txResponse = modifyTransactionFee.freezeWith(client).sign(newAdminKey).sign(adminKey).execute(client);

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

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

//v2.0.0

JavaScript

//Create the transaction
const transaction = await new ContractUpdateTransaction()
    .setContractId(contractId)
    .setAdminKey(adminKey)
    .setMaxTransactionFee(new Hbar(20))
    .freezeWith(client);

//Sign the transaction with the old admin key and new admin key
const signTx = await (await transaction.sign(newAdminKey)).sign(adminKey);

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

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

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

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

//v2.0.5

Go

//Create the transaction
transaction := hedera.NewContractUpdateTransaction().
        SetContractID(contractId).
        SetBytecodeFileID(byteCodeFileID).
        SetAdminKey(adminKey)

//Change the default max transaction fee to 20 HBAR
modifyMaxTransactionFee := transaction.SetMaxTransactionFee(hedera.HbarFrom(20, hedera.HbarUnits.Hbar))

//Freeze the transaction
freezeTransaction, err := modifyMaxTransactionFee.FreezeWith(client)
if err != nil {
        panic(err)
}

//Sign with the old admin key, sign with the new admin key, sign with the client operator account and submit to a Hedera network
txResponse, err := freezeTransaction.Sign(newAdminKey).Sign(adminKey).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 %v\n", transactionStatus)

//v2.0.0

Get transaction values

Method	Type	Requirement
getContractId()	ContractId	Required
getAdminKey()	Key	Optional
getBytecodeFileId()	FileId	Optional
getProxyAccountId()	AccountId	Optional
getContractMemo()	String	Optional
getStakedAccountId()	AccountId	Optional
getStakedNodeId()	long	Optional
getDeclineStakingReward()	boolean	Optional
getAutoRenewAccountId()	AccountId	Required
getAutoRenewPeriod()	Duration	Required

Java

//Create the transaction with an admin key
ContractUpdateTransaction transaction = new ContractUpdateTransaction()
    .setContractId(contractId)
    .setAdminKey(adminKey);

//Get admin key
transaction.getAdminKey()

//v2.0.0

JavaScript

//Create the transaction with an admin key
const transaction = new ContractUpdateTransaction()
    .setContractId(contractId)
    .setAdminKey(adminKey);

//Get admin key
transaction.getAdminKey()

//v2.0.0

Go

//Create the transaction
transaction := hedera.NewContractUpdateTransaction().
        SetContractID(contractId).
        SetBytecodeFileID(byteCodeFileID).
        SetAdminKey(adminKey)

//Get admin key
transaction.GetAdminKey()

//v2.0.0