gelato-vrf

Gelato VRF Jump Start

This repository provides example contracts and instructions for setting up Verifiable Random Function (VRF) on Gelato, utilizing Gelato VRF.

Overview

Verifiable Random Function (VRF) is a cryptographic primitive that generates unpredictable random numbers. Integrating VRF into Gelato allows for various decentralized applications (DApps) to leverage secure, on-chain randomness.

This repository includes contracts and configurations necessary for implementing VRF functionality on Gelato, making it easy for developers to integrate random number generation into their projects.

Requirements

Before beginning, make sure you have the following installed or set up on your computer beforehand.

• nvm or Node v20.0.0 or greater
• npm or yarn
• Wallet that contains BERA token (for deployment, use the Bepolia faucet from BeraHub)
• hardhat

Gelato VRF: SimpleVRFContract

Create a .env file at the project root and populate it with the following values

PRIVATE_KEY=<YOUR PRIVATE KEY>
DEDICATED_MSG_SENDER=<YOUR DEDICATED MSG SENDER>
SC_ADDRESS=<smart contract deployed in this guide>

cp .env.example .env

To deploy the SimpleVRFContract, you'll need to install the dependencies first

npm install

Then run the following hardhat command:

npx hardhat deploy --network berachainBepolia

Note

Check the deployed addresses for each network in the deployments/ folder, which is automatically created at the root of the gelato-vrf/ directory following a deployment.

• Description: Contract for using Gelato VRF directly.
• Contract Address on Berachain: use the address from your own deployment.
• Features:
  • Requests randomness from Gelato VRF.
  • Handles the fulfillment of randomness.

Create a Gelato VRF Task

Deploying your Gelato VRF instance is a straightforward process. Here's a step-by-step guide to get you started:

Step 1. Gather Necessary Addresses

Before you begin, make sure you have the address of your requester contract at hand. This will be essential for the deployment process.

Step 2. Access the VRF Deployment Portal

Navigate to the Gelato app.

Step 3. Select Deployment Network

Ensure you choose the Berachain Bepolia network where your VRF requester and receiver contracts are deployed.

Step 4. Specify the Request Contract

You'll be asked to provide the address of the Request Contract to which the Gelato nodes should respond. Enter the address you gathered in step 1.

Step 5. Launch your VRF Instance

Once all details are correctly entered, go ahead and launch your Gelato VRF instance.

Request Randomness

After deploying your contract, proceed to the .env file and replace the existing smart contract address with the one specific to your deployment.

SC_ADDRESS=<your deployed contract address>

To invoke the randomness request, you can run the requestRandomness.ts script:

npx hardhat run ./scripts/requestRandomness.ts --network berachainBepolia

This will produce a similar response:

Requesting randomness with data: 0x7465737420646174610000000000000000000000000000000000000000000000
Transaction hash: 0x1a33e33970c0c4e89589e863b8833d7da5138a4f13b7cc02da9b2d97863912df

Monitor Execution

After your randomness request has been made, monitor it from your Gelato VRF task page.