Smart Contract

Smart Contract Development on XSPACE Protocol

The XSPACE Protocol supports the development and deployment of Ethereum-compatible smart contracts, enabling seamless integration with existing blockchain tools and workflows. This guide provides an overview of smart contracts on XSPACE, including deployment, interaction, and best practices.

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Overview of XSPACE Smart Contracts

1. Ethereum Virtual Machine (EVM) Compatibility

XSPACE is EVM-compatible, meaning developers can write and deploy smart contracts using the same tools and languages (e.g., Solidity) as on Ethereum. This ensures a low learning curve for developers transitioning from other EVM-based blockchains.

2. Key Features

• High Performance: Contracts execute with near-instant finality (~1-2 seconds) thanks to XSPACE’s sharded architecture and Delegated Proof-of-Stake (DPoS 2.0).

• Low Transaction Fees: XSPACE’s efficient consensus mechanism and sharding result in significantly lower gas costs compared to Ethereum.

• Interoperability: Smart contracts can interact with external blockchains via XSPACE’s cross-chain bridges, enabling multi-chain dApps.

• Enhanced Tokenization Standards: Use the XSPACE Asset Tokenization Standard (XATS) to tokenize real-world assets with integrated metadata and compliance tools.

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Deploying Smart Contracts

Step 1: Create a Smart Contract

Smart contracts on XSPACE are written in Solidity, a popular language for EVM-based blockchains.

Example: A Simple Storage Contract

Create a new file in your contracts directory, e.g., SimpleStorage.sol:

pragma solidity ^0.8.0;

contract SimpleStorage {
    uint256 private data;

    // Set the value of `data`
    function set(uint256 _data) public {
        data = _data;
    }

    // Retrieve the value of `data`
    function get() public view returns (uint256) {
        return data;
    }
}

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Step 2: Configure the Development Environment

Ensure your hardhat.config.js file is configured for the XSPACE Testnet:

require("@nomiclabs/hardhat-waffle");

module.exports = {
  solidity: "0.8.0",
  networks: {
    xspaceTestnet: {
      url: "https://testnet.xspaceprotocol.io/rpc",
      chainId: 80001,
      accounts: ["YOUR_PRIVATE_KEY"]
    }
  }
};

Replace "YOUR_PRIVATE_KEY" with the private key of your Testnet wallet (use Metamask to export it).

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Step 3: Deploy the Smart Contract

Write a deployment script in the scripts directory, e.g., deploy.js:

async function main() {
    // Compile and deploy the SimpleStorage contract
    const SimpleStorage = await ethers.getContractFactory("SimpleStorage");
    const contract = await SimpleStorage.deploy();
    await contract.deployed();

    console.log("Contract deployed to:", contract.address);
}

main().catch((error) => {
    console.error(error);
    process.exitCode = 1;
});

Deploy the contract to the XSPACE Testnet:

npx hardhat run scripts/deploy.js --network xspaceTestnet

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Step 4: Verify Deployment

1. Note the contract address output from the deployment script.

2. Use the XSPACE Testnet Explorer to verify the contract: https://testnet-explorer.xspace.io.

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Interacting with Smart Contracts

Once deployed, you can interact with your smart contract using tools like Hardhat, Web3.js, or Ethers.js.

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Method 1: Using Hardhat Console

Hardhat provides an interactive console for directly interacting with deployed contracts.

1. Open the Hardhat console:

   npx hardhat console --network xspaceTestnet

2. Load the deployed contract:

   const contract = await ethers.getContractAt("SimpleStorage", "DEPLOYED_CONTRACT_ADDRESS");

3. Call the set function to store a value:

   await contract.set(42);

4. Retrieve the stored value using the get function:

   const value = await contract.get();
   console.log("Stored value:", value.toString());

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Method 2: Using a JavaScript dApp

Integrate your smart contract with a JavaScript frontend using Ethers.js or Web3.js.

Frontend Setup

Install Ethers.js:

npm install ethers

Connect to the XSPACE Testnet

Create a connection to the blockchain:

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

// Connect to the XSPACE Testnet
const provider = new ethers.providers.JsonRpcProvider("https://testnet.xspaceprotocol.io/rpc");

// Wallet setup
const privateKey = "YOUR_PRIVATE_KEY";
const wallet = new ethers.Wallet(privateKey, provider);

// Contract ABI and address
const abi = [
    "function set(uint256 _data) public",
    "function get() public view returns (uint256)"
];
const contractAddress = "DEPLOYED_CONTRACT_ADDRESS";

// Create a contract instance
const contract = new ethers.Contract(contractAddress, abi, wallet);

// Interact with the contract
(async () => {
    // Set a value
    const tx = await contract.set(42);
    await tx.wait();

    // Get the value
    const value = await contract.get();
    console.log("Stored value:", value.toString());
})();

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Best Practices for Smart Contract Development

1. Optimize Gas Usage:

   • Avoid unnecessary state variables and computations.

   • Use view/pure functions wherever possible.

2. Thorough Testing:

   • Test contracts locally using Hardhat or Truffle.

   • Use tools like Chai for writing test cases.

3. Security Audits:

   • Always audit smart contracts to check for vulnerabilities like reentrancy, overflow/underflow, and improper access control.

4. Use IPFS for Off-Chain Data:

   • Store large metadata (e.g., property details, asset history) off-chain on IPFS and link it to the contract.

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Next Steps

1. Build Advanced Contracts: Explore multi-shard interactions, privacy-preserving transactions (zk-SNARKs), and token standards (ERC-20/721).

2. Deploy dApps: Create decentralized applications integrating smart contracts with frontend frameworks.

3. Explore Tokenization: Use the XATS framework to tokenize real-world assets.

This guide sets the foundation for building, deploying, and interacting with smart contracts on XSPACE.