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Stablecoin Development with CDP (Collateralized Debt Positions) A decentralised stablecoin is created using crypto token development services and uses blockchain technology to issue digital assets called stablecoins, which are based on a fixed value, such as $1, and are not controlled by a central authority. Collateralised Debt Positions (CDPs) are a popular method for accomplishing this. These smart contracts control the issuance and liquidation of stablecoins according to collateral.A CDP is a smart contract that, in exchange for granting a loan in the form of stablecoins, locks up collateral, such as Ether. A CDP's salient characteristics are:Collateral: The user funds a smart contract with a specific quantity of cryptocurrency (such as ETH).Debt: Depending on the value of the supplied collateral, the user borrows stablecoins. The collateral ratio (e.g., 150%) restricts the amount of debt that can be borrowed, thus the borrower is not allowed to withdraw more stablecoins than the collateral value.Collateral Ratio: This is the proportion of money loaned in stablecoins to the amount of collateral needed. The borrower must deposit $1.50 in collateral for every $1 borrowed in stablecoin, for instance, if the collateral ratio is 150%.Liquidation: The system will sell the collateral to pay off the debt and keep the system from slipping into negative equity if the collateral's value drops below a predetermined level, meaning it is no longer sufficient to cover the borrowed debt.Repayment: After repaying the debt, the collateral is returned, and the user can do so by returning the stablecoins they borrowed.Also, Discover | AI-Powered Stablecoin Development | Streamlining StabilityStabelcoin Development with CDP (Collateralized Debt Positions)Setup1. Initialize the Projectnpm init -y2. Install Hardhatnpm install --save-dev hardhat3. Create a Hardhat Projectnpx hardhat4. Install Environment and OpenZeppelin Librariesnpm install dotenv @openzeppelin/contractsYou may also like | Best Blockchain Platforms for Stablecoin DevelopmentIn contracts folder add the following three files:1. Usdc.sol– Mock ERC20 StablecoinThis is a sample ERC20 token acting as a mock USDC, used to mint and burn tokens during borrow/repay operations.// SPDX-License-Identifier: MIT pragma solidity ^0.8.22; import "@openzeppelin/contracts/token/ERC20/ERC20.sol"; import "@openzeppelin/contracts/access/Ownable.sol"; contract USDC is ERC20, Ownable { uint8 private immutable _decimals; address public minter; constructor( string memory name_, string memory symbol_, uint8 decimals_, uint256 initialSupply ) ERC20(name_, symbol_) Ownable(msg.sender) { _decimals = decimals_; _mint(msg.sender, initialSupply); } function setMinter(address _minter) external onlyOwner { minter = _minter; } function mint(address to, uint256 amount) external { require(msg.sender == minter, "Only minter can mint"); _mint(to, amount); } function burn(address from, uint256 amount) external { require(msg.sender == minter, "Only minter can burn"); _burn(from, amount); } function decimals() public view override returns (uint8) { return _decimals; } }2. Oracle.sol– Mock Oracle ContractThis is a simple oracle contract that returns a hardcoded ETH/USD price. It can be updated by the owner to simulate live price changes.// SPDX-License-Identifier: MIT pragma solidity ^0.8.0; contract Oracle { uint256 public price = 2000 * 1e18; // $2000 per ETH address public owner; constructor() { owner = msg.sender; } function setPrice(uint256 _price) external { require(msg.sender == owner, "Only owner can set price"); price = _price; } function getPrice() external view returns (uint256) { return price; } }Also, Check | PayPal Launches its U.S. Dollar Stablecoin PayPal USD (PYUSD)3. CDPVault.sol – Core CDP ContractThis contract manages ETH collateral, allows borrowing and repayment in USDC, and handles liquidation if the collateral ratio is violated.// SPDX-License-Identifier: MIT pragma solidity ^0.8.22; import "./Usdc.sol"; import "./Oracle.sol"; contract CDPVault { USDC public stablecoin; Oracle public oracle; uint256 public constant COLLATERAL_RATIO = 150; uint256 public constant PRECISION = 1e18; mapping(address => uint256) public collateralETH; mapping(address => uint256) public debt; constructor(address _stablecoin, address _oracle) { stablecoin = USDC(_stablecoin); oracle = Oracle(_oracle); } function depositCollateral() external payable { require(msg.value > 0, "Must deposit ETH"); collateralETH[msg.sender] += msg.value; } function borrow(uint256 amount) external { require(amount > 0, "Invalid borrow amount"); uint256 ethPrice = oracle.getPrice(); uint256 collateralValue = (collateralETH[msg.sender] * ethPrice) / PRECISION; uint256 maxBorrow = (collateralValue * 100) / COLLATERAL_RATIO; require(debt[msg.sender] + amount <= maxBorrow, "Exceeds borrow limit"); debt[msg.sender] += amount; stablecoin.mint(msg.sender, amount * 1e18); } function repay(uint256 amount) external { require(debt[msg.sender] >= amount, "Repaying more than owed"); uint256 scaledAmount = amount * 1e18; stablecoin.transferFrom(msg.sender, address(this), scaledAmount); stablecoin.burn(address(this), scaledAmount); debt[msg.sender] -= amount; } function withdraw(uint256 amount) external { require( amount > 0 && collateralETH[msg.sender] >= amount, "Invalid amount" ); uint256 ethPrice = oracle.getPrice(); uint256 newCollateral = collateralETH[msg.sender] - amount; uint256 newCollateralValue = (newCollateral * ethPrice) / PRECISION; require( debt[msg.sender] == 0 || (newCollateralValue * 100) / debt[msg.sender] >= COLLATERAL_RATIO, "Would become undercollateralized" ); collateralETH[msg.sender] = newCollateral; payable(msg.sender).transfer(amount); } function liquidate(address user) external { uint256 ethPrice = oracle.getPrice(); uint256 userCollateral = collateralETH[user]; uint256 userDebt = debt[user]; require(userDebt > 0, "No debt to liquidate"); uint256 collateralValue = (userCollateral * ethPrice) / PRECISION; uint256 requiredValue = (userDebt * COLLATERAL_RATIO) / 100; require(collateralValue < requiredValue, "Position is healthy"); uint256 scaledDebt = userDebt * 1e18; stablecoin.transferFrom(msg.sender, address(this), scaledDebt); stablecoin.burn(address(this), scaledDebt); collateralETH[user] = 0; debt[user] = 0; payable(msg.sender).transfer(userCollateral); } }DeployThis deployment script uses Hardhat to build up all required smart contracts for the CDP system. First, a fictitious USDC token with a 6-decimal precision and a 1,000,000 token initial supply is deployed. A straightforward Oracle contract with a hardcoded ETH price is then deployed. The primary CDPVault contract is then deployed utilising the USDC and Oracle addresses. In order to mint and burn tokens during borrow and repay activities, it lastly configures the CDPVault as the USDC token minter.const hre = require("hardhat"); async function main() { const [deployer] = await hre.ethers.getSigners(); console.log("Deploying contracts with:", deployer.address); // Deploy USDC with 6 decimals and 1,000,000 initial supply const USDC = await hre.ethers.getContractFactory("USDC"); const usdc = await USDC.deploy( "USD Test Coin", "USDC", 6, hre.ethers.parseUnits("1000000", 6) ); await usdc.waitForDeployment(); console.log("USDC deployed at:", usdc.target); // Deploy Oracle const Oracle = await hre.ethers.getContractFactory("Oracle"); const oracle = await Oracle.deploy(); await oracle.waitForDeployment(); console.log("Oracle deployed at:", oracle.target); // Deploy CDPVault const CDPVault = await hre.ethers.getContractFactory("CDPVault"); const vault = await CDPVault.deploy(usdc.target, oracle.target); await vault.waitForDeployment(); console.log("CDPVault deployed at:", vault.target); // Set vault as the minter const tx = await usdc.setMinter(vault.target); await tx.wait(); console.log("Vault set as minter on USDC"); } main().catch((error) => { console.error(error); process.exitCode = 1; });To deploy the contracts on the Sepolia test network, you can run the following command:npx hardhat run scripts/deploy.js --network sepoliaThe USDC token, Oracle, and CDPVault contracts will be deployed on Sepolia by the script when you execute this command. After that, the CDPVault will be designated as the USDC token minter. Following a successful deployment, the console will display the deployed contract addresses and the deployer's wallet address for your testing and engagement.Also, Discover | The Ultimate Guide to Stablecoin Development 2025 EditionConclusionThis post describes how to use Hardhat to create a basic decentralised stablecoin system. The implementation of a CDPVault contract, a simple price oracle, and a mock USDC token has resulted in a functional prototype that replicates the process of ETH deposits, stablecoin borrowings, and collateralised debt positions. A more reliable DeFi application can be built upon this base with well-defined deployment procedures and a testable configuration on the Sepolia network. If you are planning to build and launch a stablecoin using CDP, connect with our skilled blockchain developers to get started.

Technology: EXPRESS.JS , COSMOS IBC more Category: Blockchain

Mudit Singh

30 Apr 2025

Developing a Peer-to-Peer Car Rental System on Blockchain (with Code) The world is shifting towards decentralized blockchain solutions, and peer-to-peer services are at the forefront of this transformation. One particularly exciting application is a decentralized peer-to-peer car rental system, where users can list, rent, and return vehicles — all without relying on traditional intermediaries — powered entirely by smart contracts. This dApp enables car owners and renters to connect directly, eliminating the need for centralized companies like Turo, Hertz, or Zipcar. Instead of placing trust in a third party, the system relies on blockchain-based smart contracts to manage:Listing cars for rentProcessing rental payments and security depositsStarting and ending rental agreementsRefunding deposits after car returnTracking user reputation and reviewsWhy Build a Car Rental System on Blockchain?Trustless Transactions — No middleman requiredTransparency — All terms and transactions are verifiable on-chainSecurity — Funds are held in escrow by smart contractsOwnership Proof — NFTs can represent cars and rental rightsGlobal Access — Anyone with a wallet can participateAlso, Read | Developing a Ride-Sharing App like Uber with BlockchainSystem OverviewOur decentralized car rental system includes:Smart Contracts for listing, renting, and returning carsWallet Integration for direct paymentsIPFS Support (optional) for storing car images and documentsReputation System using on-chain reviewsFlow Diagram:Car Owner → List Car → Set Price, Deposit, TermsRenter → Browse → Rent → Pay Rental Fee & DepositSmart Contract Holds Funds → Starts Rental TimerRenter Returns Car → Owner Confirms ReturnContract Releases Funds → Both Parties Leave ReviewsYou may also like | Blockchain Meets Mining Supply Chain for End-to-End TrackingSmart Contract: Core ImplementationHere's a basic version of the CarRental smart contract:solidity CopyEdit// SPDX-License-Identifier: MIT pragma solidity ^0.8.24; contract CarRental { struct Car { address payable owner; uint256 pricePerDay; uint256 securityDeposit; bool available; } struct Rental { address renter; uint256 startTime; uint256 endTime; uint256 totalPaid; bool active; } uint256 public carCount; mapping(uint256 => Car) public cars; mapping(uint256 => Rental) public rentals; event CarListed(uint256 indexed carId, address owner, uint256 pricePerDay, uint256 securityDeposit); event CarRented(uint256 indexed carId, address renter, uint256 startTime, uint256 endTime); event CarReturned(uint256 indexed carId, bool damaged); /// List a car function listCar(uint256 pricePerDay, uint256 securityDeposit) external { carCount++; cars[carCount] = Car( payable(msg.sender), pricePerDay, securityDeposit, true ); emit CarListed(carCount, msg.sender, pricePerDay, securityDeposit); } /// Rent a car function rentCar(uint256 carId, uint256 rentalDays) external payable { Car storage car = cars[carId]; require(car.available, "Car not available"); uint256 totalCost = (car.pricePerDay * rentalDays) + car.securityDeposit; require(msg.value >= totalCost, "Insufficient payment"); rentals[carId] = Rental( msg.sender, block.timestamp, block.timestamp + (rentalDays * 1 days), msg.value, true ); car.available = false; emit CarRented(carId, msg.sender, block.timestamp, block.timestamp + (rentalDays * 1 days)); } /// Return the car function returnCar(uint256 carId, bool damaged) external { Rental storage rental = rentals[carId]; Car storage car = cars[carId]; require(rental.active, "Rental not active"); require(rental.renter == msg.sender, "Not the renter"); rental.active = false; car.available = true; if (damaged) { // Owner keeps deposit if car is damaged car.owner.transfer(rental.totalPaid); } else { // Refund deposit to renter, rest to owner uint256 rentalFee = car.pricePerDay * ((rental.endTime - rental.startTime) / 1 days); car.owner.transfer(rentalFee); payable(rental.renter).transfer(rental.totalPaid - rentalFee); } emit CarReturned(carId, damaged); } } Also, Discover | Developing a Food Delivery App like UberEats with BlockchainConclusionThis peer-to-peer car rental system illustrates the power of decentralized applications to disrupt traditional industries. By using smart contracts, users can interact in a trustless, secure, and transparent way, with no need for centralized oversight. With continued development, features like NFT-based ownership, dispute resolution, dynamic pricing, and AI-driven reviews can make such dApps viable real-world alternatives to existing platforms. Blockchain isn't just a trend — it's the foundation of the next generation of digital services. If you have an inventive business idea and want to bring it to reality, leveraging decentralized technologies, connect with our skilled blockchain developers to get started.

Technology: ANGULAR , ReactJS more Category: Blockchain

Yogesh Sahu

30 Apr 2025

Optimism Platform: Developing and Implementing Layer 2 Smart Contracts Due to network congestion and high transaction fees, Layer 2 smart contract development was introduced to enhance scalability and efficiency. Optimism, with its unique technical design, aims to address Ethereum's scalability and fee challenges. It achieves this by maintaining continuous interaction with Ethereum's Layer 1 while processing transactions on its Layer 2 for greater cost-effectiveness and efficiency.Why use optimism ?1. It reduces gas transactionsduring transactions.2. It processes transactions efficiently.3. Like a layer 1 smart contract, it offers enhanced security.You may also like | How to Scale Smart Contracts with State ChannelsWhat is the process by which Optimism functions and manages transactions?Optimism employs a cutting-edge data compression technique called Optimistic Rollups, a revolutionary method for scaling the Ethereum blockchain developed by the Optimism Foundation. Rollups are categorized into two types: Optimistic Rollups, pioneered by the Optimism Foundation, and Zero-Knowledge Rollups (ZK Rollups).Optimistic Rollups enhance processing efficiency by offloading a significant portion of transaction data off-chain. Unlike other sidechains, they still publish a small amount of data to Ethereum's Layer 1 network for validation, ensuring robust security.Unlike ZK Rollups, which publish cryptographic proofs of transaction validity, Optimistic Rollups assume off-chain transactions are valid by default and do not include proofs for on-chain transaction batches. To prevent incorrect state transitions, fraud proofs are employed. These proofs ensure Ethereum Optimism transactions are executed correctly.At the core of this functionality is the Optimistic Virtual Machine (OVM), which acts as a sandbox environment, ensuring deterministic smart contract execution between Layer 1 and Layer 2. While both the OVM and Ethereum Virtual Machine (EVM) handle computations, the OVM serves as an interface for the EVM.The Execution Manager facilitates virtualization, enabling seamless comparison between EVM and OVM executions. The Solidity compiler plays a key role, in translating Solidity code into Yul, which is then converted into EVM instructions and compiled into bytecode. Once converted to EVM assembly, each opcode is “rewritten” into its OVM equivalent, ensuring compatibility with the Optimistic Virtual Machine (OVM).Also, Explore | Build a Secure Smart Contract Using zk-SNARKs in SolidityAdvantages of Optimiser:1. Optimism provides faster transaction rates ranging from 200 to 2000 tps compared to Ethereum layer 1 which only manages roughly 10 TPS.2. All transaction data is securely saved on Ethereum's Layer 1, ensuring that the ecosystem stays decentralized and credible.3. Optimistic Rollups are entirely Ethereum in sync, providing the same characteristics and features via EVM and Solidity.Drawbacks of Optimiser:1. With only 5.85% of its entire supply being in circulation, there is still an immense number of tokens to be produced, which could have a consequence on the market2. Optimism's market capitalization is comparable to that of Polygon, a leading scaling solution, which may convey that the company is now undervalued potentially paving the way for a price correction.You may also explore | Multi-Level Staking Smart Contract on Ethereum with SolidityPopular DApps on Optimism Blockchain:UniSwap,Stargate Finance,Sonne Finance,1inch Network,Celer Network.Steps follow to Deploy Smart Contract on optimism :Setting Up the Environment1. Install necessary tools:Npm (or yarn) and Node.js: Ensure the most recent versions are installed.Hardhat: An Ethereum development environment. Use npm to install it globally:Bash: npm install -g hardhat2. Establish a New Hardhat Project: Start a new one.Bash: npx hardhat init3. Configure the Hardhat network:Modify the hardhat.config.js file to add the testnet setup for Optimism Sepolia:require("@nomicfoundation/hardhat-toolbox"); module.exports = { solidity: "0.8.20", networks: { opSepolia: { url: 'YOUR OP_SOPOLIA TEST_NET RPC', accounts: ["YOUR_PRIVATE_KEY"], }, }, };Implement an ERC-20 token by creating a new Solidity file, mytoken.sol, and pasting the following code into your contracts directory :// SPDX-License-Identifier: MIT pragma solidity ^0.8.20; contract OPToken { string public name; string public symbol; uint8 public decimals; uint256 public totalSupply; mapping(address => uint256) public balanceOf; mapping(address => mapping(address => uint256)) public allowance; event Transfer(address indexed from, address indexed to, uint256 value); event Approval(address indexed owner, address indexed spender, uint256 value); constructor(string memory _name, string memory _symbol, uint8 _decimals, uint256 _initialSupply) { name = _name; symbol = _symbol; decimals = _decimals; totalSupply = _initialSupply * (10 ** uint256(decimals)); balanceOf[msg.sender] = totalSupply; // Assign all tokens to the deployer } function transfer(address _to, uint256 _value) public returns (bool success) { require(balanceOf[msg.sender] >= _value, "Insufficient balance"); _transfer(msg.sender, _to, _value); return true; } function _transfer(address _from, address _to, uint256 _value) internal { require(_to != address(0), "Cannot transfer to zero address"); balanceOf[_from] -= _value; balanceOf[_to] += _value; emit Transfer(_from, _to, _value); } function approve(address _spender, uint256 _value) public returns (bool success) { allowance[msg.sender][_spender] = _value; emit Approval(msg.sender, _spender, _value); return true; } function transferFrom(address _from, address _to, uint256 _value) public returns (bool success) { require(balanceOf[_from] >= _value, "Insufficient balance"); require(allowance[_from][msg.sender] >= _value, "Allowance exceeded"); _transfer(_from, _to, _value); allowance[_from][msg.sender] -= _value; return true; } }Also, Check | How to Write and Deploy Modular Smart Contracts4. Compile the Contract.Within your terminal, execute the following command:Bash: Npx Hardhat Compile5. Deploy the Contract:Make a scripts/deploy.js file to automate the deployment procedure:async function main() { const MyToken = await hre.ethers.getContractFactory("MyToken"); const myToken = await MyToken.deploy("MyToken", "MTK", 18, 1000000); await myToken.deployed(); console.log("MyToken deployed to:", myToken.address); } main().catch((error) => { console.error(error); process.exitCode = 1; });Deploy the contract via the Hardhat console:Bash:Run scripts/deploy.js --network opSepolia using npx hardhatAlso, Explore | How to Deploy a Smart Contract to Polygon zkEVM TestnetConclusion:Optimism aims to enhance the Ethereum ecosystem by offering scalable Layer 2 solutions. While its optimistic roll-up methodology shares similarities with others, its implementation and features set it apart. Currently a strong second-place contender, Optimism has the potential to challenge Arbitrum's dominance in the future. If you are looking to build your project leveraging Optimism blockchain, connect with our expert blockchain developers to get started.

Technology: ZK-SNARKS , UNISWAP more Category: Blockchain

Tushar Shrivastava

24 Dec 2024

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