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Code Examples

Ready-to-use code examples for integrating mantraUSD into your applications.

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Contract Address

Address: 0xd2b95283011E47257917770D28Bb3EE44c849f6F View on Blockscout

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Basic Balance Check

// Using ethers.js
const { ethers } = require('ethers');

const provider = new ethers.providers.JsonRpcProvider('YOUR_RPC_URL');
const contractAddress = '0xd2b95283011E47257917770D28Bb3EE44c849f6F';
const abi = ['function balanceOf(address) view returns (uint256)'];

const contract = new ethers.Contract(contractAddress, abi, provider);

async function checkBalance(address) {
  const balance = await contract.balanceOf(address);
  return ethers.utils.formatEther(balance);
}

// Usage
checkBalance('0x742d35Cc6634C0532925a3b844Bc9e7595f0bEb').then(console.log);

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Transfer Tokens

const { ethers } = require('ethers');

const provider = new ethers.providers.JsonRpcProvider('YOUR_RPC_URL');
const wallet = new ethers.Wallet('YOUR_PRIVATE_KEY', provider);
const contractAddress = '0xd2b95283011E47257917770D28Bb3EE44c849f6F';
const abi = ['function transfer(address to, uint256 amount) returns (bool)'];

const contract = new ethers.Contract(contractAddress, abi, wallet);

async function transfer(to, amount) {
  const tx = await contract.transfer(to, ethers.utils.parseEther(amount.toString()));
  console.log('Transaction hash:', tx.hash);
  await tx.wait();
  console.log('Transfer confirmed!');
}

// Usage
transfer('0x742d35Cc6634C0532925a3b844Bc9e7595f0bEb', 100);

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Get Total Supply

const { ethers } = require('ethers');

const provider = new ethers.providers.JsonRpcProvider('YOUR_RPC_URL');
const contractAddress = '0xd2b95283011E47257917770D28Bb3EE44c849f6F';
const abi = ['function totalSupply() view returns (uint256)'];

const contract = new ethers.Contract(contractAddress, abi, provider);

async function getTotalSupply() {
  const supply = await contract.totalSupply();
  return ethers.utils.formatEther(supply);
}

// Usage
getTotalSupply().then(supply => {
  console.log('Total Supply:', supply, 'mantraUSD');
});

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Listen to Transfer Events

const { ethers } = require('ethers');

const provider = new ethers.providers.JsonRpcProvider('YOUR_RPC_URL');
const contractAddress = '0xd2b95283011E47257917770D28Bb3EE44c849f6F';
const abi = [
  'event Transfer(address indexed from, address indexed to, uint256 value)'
];

const contract = new ethers.Contract(contractAddress, abi, provider);

// Listen to all transfers
contract.on('Transfer', (from, to, value, event) => {
  console.log('Transfer detected:');
  console.log('From:', from);
  console.log('To:', to);
  console.log('Amount:', ethers.utils.formatEther(value), 'mantraUSD');
  console.log('Block:', event.blockNumber);
});

// Listen to transfers to a specific address
const filter = contract.filters.Transfer(null, '0x742d35Cc6634C0532925a3b844Bc9e7595f0bEb');
contract.on(filter, (from, to, value, event) => {
  console.log('Received:', ethers.utils.formatEther(value), 'mantraUSD');
});

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React Hook Example

import { useState, useEffect } from 'react';
import { ethers } from 'ethers';

const CONTRACT_ADDRESS = '0xd2b95283011E47257917770D28Bb3EE44c849f6F';
const ABI = [
  'function balanceOf(address) view returns (uint256)',
  'function transfer(address to, uint256 amount) returns (bool)',
];

function useMantraUSD() {
  const [balance, setBalance] = useState('0');
  const [account, setAccount] = useState(null);
  const [contract, setContract] = useState(null);
  
  useEffect(() => {
    async function init() {
      if (window.ethereum) {
        const provider = new ethers.providers.Web3Provider(window.ethereum);
        const accounts = await provider.send('eth_requestAccounts', []);
        setAccount(accounts[0]);
        
        const contractInstance = new ethers.Contract(
          CONTRACT_ADDRESS,
          ABI,
          provider
        );
        setContract(contractInstance);
        
        const bal = await contractInstance.balanceOf(accounts[0]);
        setBalance(ethers.utils.formatEther(bal));
      }
    }
    init();
  }, []);
  
  const transfer = async (to, amount) => {
    if (!contract) return;
    const signer = contract.provider.getSigner();
    const contractWithSigner = contract.connect(signer);
    const tx = await contractWithSigner.transfer(
      to,
      ethers.utils.parseEther(amount.toString())
    );
    await tx.wait();
    // Refresh balance
    const newBalance = await contract.balanceOf(account);
    setBalance(ethers.utils.formatEther(newBalance));
  };
  
  return { balance, account, transfer };
}

// Usage in component
function MyComponent() {
  const { balance, account, transfer } = useMantraUSD();
  
  return (
    <div>
      <p>Balance: {balance} mantraUSD</p>
      <button onClick={() => transfer('0x...', 10)}>
        Send 10 mantraUSD
      </button>
    </div>
  );
}

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Node.js Service Example

const { ethers } = require('ethers');

class MantraUSDService {
  constructor(rpcUrl, privateKey) {
    this.provider = new ethers.providers.JsonRpcProvider(rpcUrl);
    this.wallet = new ethers.Wallet(privateKey, this.provider);
    this.contractAddress = '0xd2b95283011E47257917770D28Bb3EE44c849f6F';
    this.abi = [
      'function balanceOf(address) view returns (uint256)',
      'function transfer(address to, uint256 amount) returns (bool)',
      'function totalSupply() view returns (uint256)',
    ];
    this.contract = new ethers.Contract(
      this.contractAddress,
      this.abi,
      this.wallet
    );
  }
  
  async getBalance(address) {
    const balance = await this.contract.balanceOf(address);
    return ethers.utils.formatEther(balance);
  }
  
  async getTotalSupply() {
    const supply = await this.contract.totalSupply();
    return ethers.utils.formatEther(supply);
  }
  
  async transfer(to, amount) {
    const tx = await this.contract.transfer(
      to,
      ethers.utils.parseEther(amount.toString())
    );
    return tx.wait();
  }
}

// Usage
const service = new MantraUSDService('YOUR_RPC_URL', 'YOUR_PRIVATE_KEY');
service.getBalance('0x...').then(console.log);