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.
//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
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 |
//Create the transaction with an admin key
ContractUpdateTransaction transaction = new ContractUpdateTransaction()
.setContractId(contractId)
.setAdminKey(adminKey);
//Get admin key
transaction.getAdminKey()
//v2.0.0
