Kleverchain SDK library

The SDK module provides a quick and easy way to make contract calls to the blockchain directly.

For a more detailed and organized documentation, please visit the official Kleverchain SDK Documentation website.

Installation

$ npm install @klever/sdk

or

$ yarn add @klever/sdk

Setup

Web App

Since v3 it is ready to use since installation!

---

NodeJS

NodeJS is supported since v3.2.1

NodeJS must be above version 18.0.0

Basic usage

Web App

There are two ways to make a contract call: you can call only one method passing the contract data or you can create an instance of an account.

Both ways are very similar (as of v3), but with the account one you have additional methods for get the account info.

With a simple call:

import { web, ITransfer, TransactionType } from "@klever/sdk";

const payload: ITransfer = {
  amount: 100 * 10 ** 6,
  receiver: "receiverAddress",
  kda: "KLV",
};

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

const signedTx = await web.signTransaction(unsignedTx);

const response = await web.broadcastTransactions([signedTx]);

---

Node.js

If you are using NodeJS, before calling any methods, you should call utils.setProviders(providers) to set the network providers.

Common flow example:

import { Account, TransactionType } from "@klever/sdk";

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";

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 Kleverchain Mainnet, but if you want to use the Kleverchain Testnet or a local version of the Kleverchain, you can change the kleverWeb provider object by setting it before calling the initialize function.

In web app:

import { web, IProvider } from '@klever/sdk';
...
  const provider:IProvider = {
      api: 'https://api.testnet.klever.finance',
      node: 'https://node.testnet.klever.finance'
  };

  window.kleverWeb.provider = provider;
  web.initialize();
...

In Node.js:

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

  utils.setProviders(provider);
...

Offline build/sign transactions:

import { Transaction, Contracts, TXContract_ContractType, utils } from "@klever/sdk";
...
  // 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("100420")
    });
    
  // 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(), 
    });

  // decode TX will encode address in bech32 format and Uint8Array data into utf-8 string array
  console.log(tx.decode())
...

once transaction is signed, it can be broadcasted into network using node endpoint: http://localhost:8080/transcation/broadcast, or using await utils.broadcastTransactions([tx.toBroadcast()]).

Generating and importing accounts in Node.js

Using the SDK you can generate and import accounts using the following methods from the utils object:

• generateKeyPair
• getAddressFromPrivateKey

Generating a key pair:

import { utils } from '@klever/sdk';
...

  const { privateKey, address } = await utils.generateKeyPair();

...

Importing an account:

import { utils } from '@klever/sdk';
...
  const privateKey; // your private key
  const address = await utils.getAddressFromPrivateKey(privateKey);

...

Also, when you create an instance of an account with no private key, the SDK will generate a new key pair for you. Be sure to use the downloadAsPem account method to save the private key.

Transactions

All available transactions:

• Transfer
• Freeze
• Unfreeze
• Delegate
• Undelegate
• Claim
• Withdraw
• CreateAsset
• AssetTrigger
• ConfigITO
• CreateMarketplace
• ConfigMarketplace
• Sell
• Buy
• CancelMarketOrder
• Proposal
• Vote
• CreateValidator
• ConfigValidator
• Unjail
• SetAccountName
• UpdateAccountPermission

Usage Inside a Context (Web App)

If you want a global instance of your account to use throughout your app, you can create a custom hook to help you with that. Using React as an example, you can create a MyCustomHook.tsx file and create your provider as follows:

import { useState, createContext, useContext } from "react";
import { Account, utils } from "@klever/sdk";

interface ISdkContext {
  isLoaded(): Promise<boolean>;
  getAccount(): Account | null;
  setAccount(account: Account): void;
}

const SdkContext = createContext({} as ISdkContext);

const SdkProvider: React.FC = ({ children }) => {
  const [acc, setAcc] = useState<Account | null>(null);

  const values: ISdkContext = {
    isLoaded: () => utils.isKleverWebLoaded(),
    getAccount: () => acc,
    setAccount: (account) => setAcc(account),
  };
  return <SdkContext.Provider value={values}>{children}</SdkContext.Provider>;
};

const useSdk = () => useContext(SdkContext);

export { SdkContext, SdkProvider, useSdk };

And wrap your entire App.tsx in it:

import { SdkProvider } from './MyCustomHook';

...
  <SdkProvider>
    ...
      <App /> // or <Router /> or <Component />
    ...
  </SdkProvider>
...

With that, you can use it on any child component you want, without the need to instantiate an account every time:

import { useSdk } from './MyCustomHook';
...
const sdk = useSdk();
const account = sdk.getAccount();
...
await account.buildTransaction([
      {
        payload,
        type: TransactionType.Transfer,
      },
]);
...

The same pattern of global provider can be achieved in any framework you want, not only React.