Client

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You will need the following pieces of information to construct your Hedera client. 
User Information
The operator is the user paying for the transactions fees.  
Operator ID: The account ID of the user paying for the transaction/query fees
Operator key: The private key of the user paying for the transaction/query fees
You can store these variables in a .env file at the root directory of the sdk. Please see the env.sample file in the SDK for how to set this up.
Constructor
Type
Description
Client(<nodes>)
Map<accountId, string>
Constructs a client object
new Client()
Basic
Methods
Type
Description
forTestnet()
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Configures a client for Hedera testnet access
forMainnet()
​
Configures a client for Hedera mainnet access
forPreviewnet()
​
Configures a client for Hedera previewnet access
setOperator(<operatorId>, <operatorKey>)
AccountId,
ED25519PrivateKey
Defaults the operator account ID and key such that all generated transactions will be paid for by this account Id and and signed by this key
Java
JavaScript
Java
// Configures testnet client
Client client = Client.forTestnet()
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// Defaults the operator account ID and key such that all generated transactions will be paid for
// by this account and be signed by this key
client.setOperator(OPERATOR_ID, OPERATOR_KEY);
JavaScript
// Configures testnet client
const client = Client.forTestnet()
​
// Defaults the operator account ID and key such that all generated transactions will be paid for
// by this account and be signed by this key
client.setOperator(operatorAccount, operatorPrivateKey);
Advanced
Method
Type
Description
fromJson(<json>)
String
Configures a client based off the given JSON string
fromJson(<json>)
Reader
Configures a client based off the given JSON reader
fromFile(<fileName>)
String
Configures a client based on a JSON file at the given path
fromFile(<file>)
File
Configures a client based on a JSON file.
replaceNodes(<nodes>)
Map<AccountId, String>
Replace all nodes in this Client with a new set of nodes (e.g. for an Address Book update). If a node URL for a given account ID is the same, it is not replaced.
setMaxTransactionFee(<fee>)
long
Set the maximum fee to be paid for transactions executed by this client. The actual fee may be less, but will never be greater than this value.
setMaxTransactionFee(<fee>)
Hbar
Set the maximum fee to be paid for transactions executed by this client. The actual fee may be less, but will never be greater than this value.
setMaxQueryPayment(<maxQueryPayment>)
long
Set the maximum default payment value allowable for queries.
setMaxQueryPayment(<maxQueryPayment>)
Hbar
Set the maximum default payment allowable for queries.
getMaxQueryPayment()
long
Returns the maximum payment value
getMaxTransactionFee()
long
Returns the set maximum fee
The max transaction fee and max query payment are both set to 100_000_000 tinybar (1 hbar).  This amount can be modified by using setMaxTransactionFee()and setMaxQueryPayment().

Keys

Address Book

Last updated 2 months ago

Constructor	Type	Description
`Client(<nodes>)`	Map<accountId, string>	Constructs a client object

Methods	Type	Description
`forTestnet()`		Configures a client for Hedera testnet access
`forMainnet()`		Configures a client for Hedera mainnet access
`forPreviewnet()`		Configures a client for Hedera previewnet access
`setOperator(<operatorId>, <operatorKey>)`	AccountId, ED25519PrivateKey	Defaults the operator account ID and key such that all generated transactions will be paid for by this account Id and and signed by this key

Method	Type	Description
`fromJson(<json>)`	String	Configures a client based off the given JSON string
`fromJson(<json>)`	Reader	Configures a client based off the given JSON reader
`fromFile(<fileName>)`	String	Configures a client based on a JSON file at the given path
`fromFile(<file>)`	File	Configures a client based on a JSON file.
`replaceNodes(<nodes>)`	Map<AccountId, String>	Replace all nodes in this Client with a new set of nodes (e.g. for an Address Book update). If a node URL for a given account ID is the same, it is not replaced.
`setMaxTransactionFee(<fee>)`	long	Set the maximum fee to be paid for transactions executed by this client. The actual fee may be less, but will never be greater than this value.
`setMaxTransactionFee(<fee>)`	Hbar	Set the maximum fee to be paid for transactions executed by this client. The actual fee may be less, but will never be greater than this value.
`setMaxQueryPayment(<maxQueryPayment>)`	long	Set the maximum default payment value allowable for queries.
`setMaxQueryPayment(<maxQueryPayment>)`	Hbar	Set the maximum default payment allowable for queries.
`getMaxQueryPayment()`	long	Returns the maximum payment value
`getMaxTransactionFee()`	long	Returns the set maximum fee