NEXT SDK (via Developer Center)

The NEXT SDK allows you to integrate your dApps with the Bitkub NEXT Wallet, which provides native support for the KUB network. It offers various methods for managing user authentication, retrieving user information, and executing transactions on the blockchain. With the NEXT SDK, your dApps can integrate with the Bitkub NEXT Wallet Authentication services and submit transactions directly on the network.

Prerequisites

Before you install or interact with the NEXT SDK, we highly recommend generating the necessary keys, including the Client ID and Project ID, using the KUB Developer Center.

Installation

To install the NEXT SDK, you can use npm, pnpm, or yarn.

npm

npm install @bitkub-chain/sdk.js

pnpm

pnpm install @bitkub-chain/sdk.js

yarn

yarn add @bitkub-chain/sdk.js

Initialization

To initialize the SDK, create lib/bitkubchain-sdk/index.ts at the root project with the clientID and projectID that has been generated from the KUB Developer Center.

import { initializeSDK, Network } from '@bitkub-chain/sdk.js';

const clientID = 'your-client-id';
const projectID = 'your-project-id';
const network = Network.BKC_TESTNET;
const initOpts = {
  loginRedirectPath: '/oauth/callback',
};

const sdk = initializeSDK(clientID, projectID, network, initOpts);

Authentication

To begin with authentication, you have to set up OAuth to allow your dApp to log in with Bitkub NEXT. The first step is to create /oauth/callback page, you can use the following code:

import { useEffect } from 'react'
import { sdk } from '@lib/bitkubchain-sdk'

export default function Page() {
  useEffect(() => {
    const code = new URLSearchParams(window.location.search).get('code')
    if (code) {
      exchange(code)
    }
  }, [])

  const exchange = async (code: string) => {
    await sdk.exchangeAuthorizationCode(code)
    window.close()
  }

  return (
    <div>
      <h2>Callback Page</h2>
      <p>Exchanging code for tokens...</p>
    </div>
  )
}

Redirect URI

You can visit the KUB Developer Center to configure your redirect URI for your dApp.

If you have not specified a loginRedirectPath, the default redirect URI will be /oauth/callback. You should configure it as follows:

http://your-application-domain.com/oauth/callback

If you have specified a custom loginRedirectPath, update your redirect UI as follows:

http://your-application-domain.com/your-custom-loginRedirectPath

Login

Opens a login window for Bitkub NEXT.

await sdk.loginWithBitkubNext();

Logout

Logs out the current user.

await sdk.logout();

Exchange Authorization Code

Exchanges the OAuth code for access and refresh tokens.

const code = 'authorizationCode';
await sdk.exchangeAuthorizationCode(code);

User Information

Get User Information

Returns an object containing user details.

const userInfo = await sdk.getUserInfo();

Get Wallet Address

Fetches the user's wallet address.

const walletAddress = await sdk.getUserWalletAddress();

Get Phone Number

Fetches the user's phone number.

const tel = await sdk.getUserTel();

Get Email

Fetches the user's email address.

const email = await sdk.getUserEmail();

Get User ID

Fetches the user's unique ID.

const userID = await sdk.getUserID();

Balances

Native Balance

Returns the user's native balance in wei.

const balance = await sdk.getBalanceNative();

If the network is Network.BKC_MAINNET or Network.BKC_TESTNET, KKUB balance will be returned. Otherwise, the native currency of the network will be returned.

ERC-20 Token Balance

Returns the balance of a specific ERC-20 token in wei.

const balance = await sdk.getBalance20(tokenAddress);

ERC-721 Token Balance

Returns the number of ERC-721 tokens owned by the user.

const balance = await sdk.getBalance721(tokenAddress);

ERC-1155 Token Balance

Returns the quantity of a specific ERC-1155 token owned by the user.

const balance = await sdk.getBalance1155(tokenAddress, tokenID);

Token Approval and Transfers

Users must approve an allowance before transferring KAP20 to ensure that only authorized smart contracts can spend their tokens, preventing unauthorized access and protecting their assets.

Get Token Allowance

Gets the current token allowance for a given spender in wei.

const allowanceAmount = await sdk.getAllowanceToken(tokenAddress, spenderAddress);

Approve Token

Approves a spender to use a specified amount of tokens.

const result = await sdk.approveToken(tokenAddress, amount, spenderAddress);

Transfer Native Token

Transfers native KUB to a recipient.

const result = await sdk.transferNative(toAddress, amount);

Transfer ERC-20 Token

Transfers a specified ERC-20 token to a recipient.

const result = await sdk.transfer20(tokenAddress, toAddress, amount);

NFT Approval and Transfers

Users must approve before transferring NFTs to ensure that only authorized smart contracts can send their NFTs, preventing unauthorized access and protecting their assets.

NFT Approval

Checks if a given operator is approved for the user's NFT.

const isApprovedNFT = await sdk.getIsApprovedNFT(tokenAddress, operatorAddress);

Approve NFT

Grants approval to an operator to manage the user's NFT.

const result = await sdk.approveNFT(tokenAddress, operatorAddress);

Transfer ERC-721 Token

Transfers an ERC-721 token to a recipient.

const result = await sdk.transfer721(tokenAddress, toAddress, tokenID);

Transfer ERC-1155 Token

Transfers a quantity of an ERC-1155 token to a recipient.

const result = await sdk.transfer1155(tokenAddress, toAddress, tokenID, amount);

Custom Transaction

Sends a custom smart contract transaction using human-readable ABI and parameters.

const result = await sdk.sendCustomTx(toAddress, functionReadableABI, methodParams);

Fetch Transaction Details

Returns the details of a submitted transaction using its queue ID.

const details = await sdk.getTransactionDetails(queueId);

Smart Contract Design for NEXT SDK

To allow Bitkub NEXT users to write data on a smart contract, you need to design the smart contract with additional functions. The additional functions are called through the CallHelper smart contract to execute commands on behalf of the Bitkub NEXT users. The function must also use an extra address _bitkubNext parameter at the end of the function.

Example

This function for buying an NFT requires 2 parameters, which are _recipeIndex and _amount. MetaMask or other wallets can call this function to buy an NFT.

function buyNft(uint256 _recipeIndex, uint256 _amount) external

The function must use an extra address _bitkubNext parameter at the end of the function to allow Bitkub NEXT users to call this function to buy an NFT.

function buyNft(uint256 _recipeIndex, uint256 _amount, address _bitkubNext) external onlySdkCallHelperRouter

You can now apply the human-readable ABI when you are calling the NEXT SDK for your custom transaction.

const functionReadableABI = "buyNft(uint256 _recipeIndex, uint256 _amount, address _bitkubNext)"
const methodParams = [1, 1]

SDK CallHelper Router

When an end user invokes a function through the SDK library, the msg.sender interacting with your smart contract will be sdkCallHelperRouter. To ensure that only authorized calls are made to this function, you must include a modifier to check that msg.sender equals sdkCallHelperRouter.

Example Modifier

modifier onlySdkCallHelperRouter() {
   require(msg.sender == sdkCallHelperRouter, "Authorization: restricted only SDK CallHelper Router");
   _;
}

Confirm that the address of the sdkCallHelperRouter for Network.BKC_TESTNET is 0x96f4C25E4fEB02c8BCbAdb80d0088E0112F728Bc.