Chainlink Fullstack Demo App

LIVE DEMO

End-to-end implementation of the following Chainlink features using Hardhat development environment and Next.js frontend framework:

• Request & Receive data
• Chainlink Price Feeds
• Chainlink VRF

Built with:

• Next.js
• TypeScript
• Hardhat
• TypeChain
• Ethers.js
• useDApp
• Chakra UI
• Linting with ESLint
• Formatting with Prettier

Requirements

• Node
• Yarn
• Git

In order to use the frontend portion of the demo application you will need:

• A crypto wallet such as Metamask or Coinbase Wallet
• Test $LINK for the relevant testnet. You can get some at the Chainlink Faucets page.
• Test $ETH to pay for gas costs. You can get some at the Chainlink Faucets page.

Quick Start

Clone the repo and install all dependencies:

git clone https://github.com/smartcontractkit/chainlink-fullstack
cd chainlink-fullstack

git submodule init
git submodule update

yarn install

Start up the local Hardhat network and deploy all contracts:

yarn chain

In a second terminal start up the local development server run the front-end app:

yarn dev

To interact with the local network, follow this step-by-step guide on how to use MetaMask with a Hardhat node.

If you've set the mnemonic from MetaMask the first 20 accounts will be funded with ETH.

Environment Variables

To make setting environment variables easier there are .env.example files in the hardhat and frontend workspaces. You can copy them to new .env files and replace the values with your own.

Hardhat

Front-end

Deploy Contracts

This will run the deploy scripts to a local Hardhat network:

yarn deploy

To deploy on a public network:

yarn deploy --network goerli

Before deploying RandomSVG contract on a public network, an ID of a prefunded VRF subscription must be set in helper-hardhat-config.ts.

See how to Create and Fund a Subscription.

Auto-Funding

The Hardhat project will attempt to auto-fund any newly deployed contract that uses Any-API or VRF, which otherwise has to be done manually.

The amount in LINK to send as part of this process can be modified in this Hardhat Config, and are configurable per network.

If you wish to deploy the smart contracts without performing the auto-funding, run the following command when doing your deployment:

yarn deploy --tags main

Test

If the test command is executed without a specified network it will run locally and only perform the unit tests:

yarn test:contracts

Integration tests must be run on a public testnet that has Chainlink oracles responding:

yarn test:contracts --network goerli

For coverage report:

yarn coverage:contracts

Verify on Etherscan

You'll need an ETHERSCAN_API_KEY environment variable. You can get one from the Etherscan API site.

npx hardhat verify --network <NETWORK> <CONTRACT_ADDRESS> <CONSTRUCTOR_PARAMETERS>

example:

npx hardhat verify --network goerli 0x9279791897f112a41FfDa267ff7DbBC46b96c296 "0x9326BFA02ADD2366b30bacB125260Af641031331"

Format

Fix formatting according to prettier config in the respective workspace:

yarn format:frontend
yarn format:hardhat

Lint

yarn lint:frontend

Testnet Contracts

This repo includes deployed and verified contracts on Goerli so the front-end can run without the need to deploy them.

Once the deploy command is executed on any network the contracts config will be overwritten and you can start from scratch with your own deployments.

Sepolia

Goerli

Kovan (deprecated)

Rinkeby (deprecated)

References

• Chainlink Docs
• Chainlink Hardhat Box
• Scaffold ETH