Here is a draft article on implementing Chainlink VRFv2 with an Upgradeable Transparent Proxy smart contract:
Implementing Chainlink VRFv2 with Upgradeable Transparent Proxy: A Guide
Chainlink VRFv2 (Voting on the Future of Blockchain) and its variant, VRFv2+ (with additional features), offer a more efficient way to interact with decentralized applications (dApps). However, implementing these protocols in an upgradeable smart contract can be challenging. In this article, we will walk you through the process of implementing Chainlink VRFv2 with an Upgradeable Transparent Proxy smart contract.
Why implement Chainlink VRFv2?
Before diving into the implementation, it’s essential to understand why you want to use Chainlink VRFv2 and its variant. These protocols provide a more secure, decentralized way to vote on block rewards, and they also enable the creation of non-custodial voting platforms.
Upgradeable Transparent Proxy (UTP)
The UTP is an upgradeable transparent proxy smart contract that allows for seamless upgrades without compromising the security of the underlying protocol. Here’s why we’ll focus on implementing Chainlink VRFv2 with this smart contract:
- Upgradeability
: The UTP provides an upgrade mechanism, which means you can update the smart contract while keeping your existing users and their balances intact.
- Transparency: The UTP is designed to be transparent, ensuring that the voting process remains decentralized and fair.
Implementing Chainlink VRFv2 with Upgradeable Transparent Proxy
To implement Chainlink VRFv2 with an Upgradeable Transparent Proxy smart contract, follow these steps:
Step 1: Set up the UTP
Create a new UTP project using Solidity (version 0.6.17 or higher) and Hardhat. You can use the official @hardhat-dev/ethers package to generate the necessary artifacts.
npx hardhat develop --network ganache
Step 2: Define the Chainlink VRFv2 Proxy Contract
Create a new file named ChainlinkVrfProxy.js and define the proxy contract. This contract will interact with Chainlink’s VRF service.
const ethers = require("ethers");
// Import the Chainlink API
const ChainlinkApi = {
vrf: require("@openzeppelin/chainlinks-vrf-proposal-implementation"),
};
class ChainlinkVrfProxy {
async deploy(chainlinkAddress, options) {
// Deploy the proxy contract using Hardhat's deploy function
const deployment = await ethers.getContractFactory("ChainlinkVrfProxy");
this.proxy = await deployment.deploy(
chainlinkAddress,
options
);
}
async callFunction(
proxyAddress,
options,
callbackAddress,
callback ABI
) {
// Call the function on the Chainlink VRF service
const result = await new ethers.Contract(proxyAddress, callbackABI, this.proxy).call({
...options,
callbackAddress,
callback,
});
return result;
}
}
Step 3: Implement the Upgradeable Transparent Proxy
Create a new file named UpgradeableTransparentProxy.js and implement the upgradeable transparent proxy. This contract will allow you to update the Chainlink VRF service without affecting your existing users.
“`javascript
const ethers = require(“ethers”);
class UpgradeableTransparentProxy {
constructor(proxyAddress, options) {
this.proxyAddress = proxyAddress;
this.options = options;
}
async upgrade() {
// Check if the proxy contract is already deployed with a new ABI
const existingContractAbi = await this.proxy.getABI();
if (existingContractAbi !== this.options.abi) {
// Update the Chainlink VRF service using the new ABI and options
const newContractAbi = await this.proxy.deploy(
this.proxyAddress,
this.options
);
return ethers.utils.abis.