Callback Page
Exchanging code for tokens...
)
}
```
### Redirect URI
You can visit the [KUB Playground](https://playground.kubchain.com/) 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:
```url
http://your-application-domain.com/oauth/callback
```
If you have specified a custom `loginRedirectPath`, update your redirect UI as follows:
```url
http://your-application-domain.com/your-custom-loginRedirectPath
```
### Login
Opens a login window for KUB Wallet.
```javascript
await sdk.loginWithBitkubNext();
```
### **Logout**
Logs out the current user.
```javascript
await sdk.logout();
```
### Exchange Authorization Code
Exchanges the OAuth code for access and refresh tokens.
```javascript
const code = 'authorizationCode';
await sdk.exchangeAuthorizationCode(code);
```
## User Information
### Get User Information
Returns an object containing user details.
```javascript
const userInfo = await sdk.getUserInfo();
```
### **Get Wallet Address**
Fetches the user's wallet address.
```javascript
const walletAddress = await sdk.getUserWalletAddress();
```
### Get Phone Number
Fetches the user's phone number.
```javascript
const tel = await sdk.getUserTel();
```
### **Get Email**
Fetches the user's email address.
```javascript
const email = await sdk.getUserEmail();
```
### **Get User ID**
Fetches the user's unique ID.
```javascript
const userID = await sdk.getUserID();
```
## Balances
### Native Balance
Returns the user's native balance in *wei*.
```javascript
const balance = await sdk.getBalanceNative();
```
{% hint style="info" %}
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.
{% endhint %}
### KAP-20 Token Balance
Returns the balance of a specific KAP-20 token in *wei*.
```javascript
const balance = await sdk.getBalance20(tokenAddress);
```
### **KAP-721 Token Balance**
Returns the number of KAP-721 tokens owned by the user.
```javascript
const balance = await sdk.getBalance721(tokenAddress);
```
### **KAP-1155 Token Balance**
Returns the quantity of a specific KAP-1155 token owned by the user.
```javascript
const balance = await sdk.getBalance1155(tokenAddress, tokenID);
```
## Token Approval and Transfers
Users must approve an allowance before transferring KAP-20 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*.
```javascript
const allowanceAmount = await sdk.getAllowanceToken(tokenAddress, spenderAddress);
```
### Approve Token
Approves a spender to use a specified amount of tokens.
```javascript
const result = await sdk.approveToken(tokenAddress, amount, spenderAddress);
```
### **Transfer Native Token**
Transfers native KUB to a recipient.
```javascript
const result = await sdk.transferNative(toAddress, amount);
```
### **Transfer KAP-20 Token**
Transfers a specified KAP-20 token to a recipient.
```javascript
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.
```javascript
const isApprovedNFT = await sdk.getIsApprovedNFT(tokenAddress, operatorAddress);
```
### Approve NFT
Grants approval to an operator to manage the user's NFT.
```javascript
const result = await sdk.approveNFT(tokenAddress, operatorAddress);
```
### Transfer KAP-721 Token
Transfers a KAP-721 token to a recipient.
```javascript
const result = await sdk.transfer721(tokenAddress, toAddress, tokenID);
```
### **Transfer KAP-1155 Token**
Transfers a quantity of a KAP-1155 token to a recipient.
```javascript
const result = await sdk.transfer1155(tokenAddress, toAddress, tokenID, amount);
```
## Custom Transaction
Sends a custom smart contract transaction using human-readable ABI and parameters.
```javascript
const result = await sdk.sendCustomTx(toAddress, functionReadableABI, methodParams);
```
## Fetch Transaction Details
Returns the details of a submitted transaction using its queue ID.
```javascript
const details = await sdk.getTransactionDetails(queueId);
```
## Smart Contract Design for NEXT SDK
To allow KUB Wallet 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 KUB Wallet 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.
```solidity
function buyNft(uint256 _recipeIndex, uint256 _amount) external
```
The function must use an extra `address _bitkubNext` parameter at the end of the function to allow KUB Wallet users to call this function to buy an NFT.
```solidity
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.
```javascript
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` interaction 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
```solidity
modifier onlySdkCallHelperRouter() {
require(msg.sender == sdkCallHelperRouter, "Authorization: restricted only SDK CallHelper Router");
_;
}
```
{% hint style="warning" %}
Confirm that the address of the `sdkCallHelperRouter` for `Network.BKC_TESTNET` is `0x96f4C25E4fEB02c8BCbAdb80d0088E0112F728Bc`.
{% endhint %}
---
# Agent Instructions: Querying This Documentation
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Perform an HTTP GET request on the current page URL with the `ask` query parameter:
```
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