Node.js

Here are the articles in this section:

Before calling any methods, you should call utils.setProviders(providers) to set the network providers.

Common flow example:

import { Account, TransactionType } from '@klever/sdk-node'

const payload = {
  amount,
  receiver,
  kda,
}

const privateKey = 'yourPrivateKey'

const account = new Account(privateKey)
await account.ready

const unsignedTx = await account.buildTransaction([
  {
    payload,
    type: TransactionType.Transfer,
  },
])

const signedTx = await account.signTransaction(unsignedTx)

const broadcastRes = await account.broadcastTransactions([signedTx])

console.log(broadcastRes)

Quick send example:

import { Account, TransactionType } from '@klever/sdk-node'

const payload = {
  amount,
  receiver,
  kda,
}

const privateKey = 'yourPrivateKey'

const account = new Account(privateKey)
await account.ready

const broadcastRes = await account.quickSend([
  {
    payload,
    type: TransactionType.Transfer,
  },
]) // the same as buildTransaction + signTransaction + broadcastTransactions

console.log(broadcastRes)

Changing Network

The default network is the Klever Blockchain Mainnet, but if you want to use the Klever Blockchain Testnet or a local version of the Klever Blockchain, you can change the provider object by setting it before calling other methods.

import { utils, IProvider } from "@klever/sdk-node";
...
  const provider: IProvider = {
    api: "https://api.testnet.klever.org",
    node: "https://node.testnet.klever.org",
  };

  utils.setProviders(provider);
...

Offline Build/Sign Transaction

If you need to build the transaction by hand, we provide methods for you to do it offline as follows:

import { Transaction, Contracts, TXContract_ContractType, utils } from "@klever/sdk-node";
...
  // text encoder UTF-8
  const enc = new TextEncoder();

  const privateKey = "001122..."; // sender`s private key 32 bytes hex format
  // decode addresses sender/receiver
  const senderDecoded = await utils.decodeAddress("klv1vq9f7xtazuk9y3n46ukthgf2l30ev2s0qxvs6dfp4f2e76sfu3xshpmjsr");
  const receiverDecoded = await utils.decodeAddress("klv1fpwjz234gy8aaae3gx0e8q9f52vymzzn3z5q0s5h60pvktzx0n0qwvtux5");
  const accountNonce = 100

  // create transfer contract
  const transfer = Contracts.TransferContract.fromPartial({
      ToAddress: receiverDecoded,
      AssetID: enc.encode("KLV"),
      Amount: 100 * 10 ** 6, // Must be in units (check asset precision) -> 100 KLV = 100 * 10^6
    });

  // create base transaction
  const tx  = new Transaction({
      Sender: senderDecoded,
      Nonce: accountNonce,
      BandwidthFee: 1000000,
      KAppFee: 500000,
      Version: 1,
      ChainID: enc.encode("109")
    });

  // add contract to transaction
  tx.addContract(TXContract_ContractType.TransferContractType, transfer);

  // signature transaction
  await tx.sign(privateKey);

  console.log("Transaction Info", {
      "Wired Proto": tx.hex(),
      "To Broadcast Format": tx.toBroadcast(),
      "Json Format": tx.toJSON(),
    });
...

All Account methods

All methods that can be called by an account instance.

Method	Parameters	Return	Description
getBalance	()	number	Gets that account instance's balance
getNonce	()	number	Gets that account instance's nonce
getAddress	()	string	Gets that account instance's address
sync	()	`Promise<void>`	Syncs that account instance's balance and nonce with the provided node.
getInfo	()	`Promise<IAccountInfo>`	Returns that address' info from the provided node.
buildTransaction	(contracts: IContractRequest[], txData?: string[], options?: ITxOptionsRequest)	`Promise<ITransaction>`	Builds a simplified transaction into a transaction ready to be signed.
signMessage	(message: string)	`Promise<string>`	Uses the account instance private key to sign any message.
signTransaction	(tx: ITransaction)	`Promise<ITransaction>`	Uses the account instance private key to sign a transaction.
quickSend	(contracts: IContractRequest[], txData?: string[], options?: ITxOptionsRequest)	`Promise<IBroadcastResponse>`	Simplifies the build/sign/broadcast flow into a single method.
downloadAsPem	(path?: string)	`Promise<void>`	Saves the `.pem` file for that account instance private key and address.
broadcastTransactions	`(txs: string[] \| ITransaction[])`	`Promise<IBroadcastResponse>`	Broadcasts an array of transactions to the provided node.
validateSignature	(message: string, signature: string)	`Promise<boolean>`	Checks if a signature is compatible with a given address and message.

All utility methods

All method packed into the utils object.

Method	Parameters	Return	Description
getAddressFromPrivateKey	(privatekey: string)	`Promise<string>`	Gets the address for the given РК based on the ED25519 curve and bech32 address conversion.
generateKeyPair	()	`Promise<{ privatekey: string; address: string; }>`	Generates a new private key/address pair, based on the ED25519 curve and bech32 address conversion.
getProviders	()	IProvider	Gets the current provider object.
setProviders	(providers: IProvider)	void	Sets the provider object.
broadcastTransactions	(txs: ITransaction[])	`Promise<IBroadcastResponse>`	Broadcasts an array of transactions to the provided node.
decodeTransaction	(tx: ITransaction)	`Promise<IDecodedTransaction>`	Decodes a built transaction to a more human-readable JSON.
transactionsProcessed	(txs: Promise[], tries?: number)	`Promise<IDecodedTransaction[]>`	Resolves when all the broadcasted transactions are processed on chain, rejects when the try limit is reached.
accountsReady	(accounts: Account[])	`Promise<void>`	Resolves when all the accounts in the array are initialized.
validateSignature	(message: string, signature: string, address: string)	`Promise<boolean>`	Checks if a signature is compatible with a given address and message.
decodeAddress	(address: string)	`Promise<Uint8Array>`	Decodes an address to a Uint8Array.
toHex	(data: Uint8Array)	string	Helper method to convert Uint8Array to a hex string.
fromHex	(hex: string)	Uint8Array	Helper method to convert a hex string to a Uint8Array.
validateAddress	(address: string)	`Promise<boolean>`	Checks if an address is valid for the Klever Blockchain standard.

Auxiliary Scripts

In this section, we provide scripts to automate the most commonly executed transaction patterns in Klever Blockchain.

Mint + UpdateMetadata

Each Update Metadata has a Kapp Fee of 2KLV, and the Bandwidth Fee depends on the size of the metadata

metadataScript.js

import { Account, utils, TransactionType } from '@klever/sdk-node'

utils.setProviders({
  api: 'https://api.devnet.klever.org',
  node: 'https://node.devnet.klever.org',
})

const privateKey = 'Your PrivateKey'
const mainAccount = new Account(privateKey)
await mainAccount.ready
const receiverAccount = mainAccount.getAddress() // the account receiver of the NFTs

const assetTriggerMint = {
  amount: 50, // any amount you want, up to 50
  assetId: 'Your AssetId',
  triggerType: 0, // Mint
}

const contracts = [
  {
    type: TransactionType.AssetTrigger,
    payload: {
      ...assetTriggerMint,
      receiver: receiverAccount,
    },
  },
]

const transactionRes = [mainAccount.quickSend(contracts)]
const result = await utils.transactionsProcessed(transactionRes)
const arrayAssetId = []

if (result[0].transaction.status !== 'success') {
  throw new Error(`Transaction failed: ${result[0].transaction.resultCode}`)
}

result[0].transaction.receipts.slice(2).forEach((element) => {
  if (!element.assetId.includes('/')) {
    throw new Error(
      `${element.assetId} is not a NFT. The amount was minted but the metadata can't be updated`,
    )
  }
  arrayAssetId.push(element.assetId)
})

const updateMetaDataContracts = []
const updateMetaDataDatas = []
arrayAssetId.forEach((assetId) => {
  updateMetaDataContracts.push({
    type: TransactionType.AssetTrigger,
    payload: {
      triggerType: 8,
      assetId: assetId,
      mime: 'application/json', // You can use any MIME type.
      // Here is a list of the most common ones:
      // https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/MIME_types/Common_types
      receiver: receiverAccount,
    },
  })
  updateMetaDataDatas.push(JSON.stringify({ assetId })) // You can send any metadata for the given assetId here
})

const requestArray = []
for (
  let index = 0;
  index < updateMetaDataContracts.length;
  index = index + 20 // The amount of contracts per transaction is limited to 20
) {
  const request = await mainAccount.quickSend(
    updateMetaDataContracts.slice(
      index,
      index + 20 < updateMetaDataContracts.length
        ? index + 20
        : updateMetaDataContracts.length,
    ),
    updateMetaDataDatas.slice(
      index,
      index + 20 < updateMetaDataContracts.length
        ? index + 20
        : updateMetaDataContracts.length,
    ),
  )
  requestArray.push(request)
}

const resultUpdateMetaData = await utils.transactionsProcessed(requestArray)
resultUpdateMetaData.forEach((element, index) => {
  console.log(`Hash ${index}: ${element.transaction.hash}`)
})