

This page explains how to install and use the Chainlink Library in your projects.
If you're new to smart contract development and want a step-by-step guide, try out our Beginner Walkthrough
Install into Existing Projects
Chainlink is supported by Hardhat, Brownie, Truffle and other frameworks.
If you already have a project, you can add Chainlink to it by using the following package managers.
NPM
Install using NPM
npm install @chainlink/contracts --save
Yarn
Install using Yarn
yarn add @chainlink/contracts
Create a New Project
If you're creating a new project from scratch, these commands will help you set up your project to interact with Chainlink.
Hardhat Box
Install hardhat
npm install --save-dev hardhat
Then, clone the boilerplate repository.
git clone https://github.com/smartcontractkit/chainlink-hardhat-box
cd chainlink-hardhat-box
For more information on Hardhat, see our blog post How to use Hardhat with Chainlink. Alternatively, visit the repo for more instructions.
Brownie Mix
Install Brownie with pip:
pip install eth-brownie
With Brownie installed, run the commands below to open a Brownie project into a new directory.
mkdir MyChainlinkProject
cd MyChainlinkProject/
brownie bake chainlink-mix
cd chainlink-mix
For more information on working with Bownie, see our blog how to use Brownie with Chainlink or visit the repo to learn more.
Environment variables are required when working with Brownie. Learn how to set environment variables.
Truffle Box
Install Truffle with NPM:
npm install truffle -g
Once installed, unbox the Chainlink box.
mkdir MyChainlinkProject
cd MyChainlinkProject/
truffle unbox smartcontractkit/box
For more details on how to use the Truffle, see our blog post. Alternatively, visit the repo for more information.
Using Chainlink Contracts
Once you have the Chainlink library installed, you can leverage the Chainlink ecosystem.
If you're interested in retrieving up to date crypto prices in your contracts, learn more about our Price Feeds.
If you need to consume randomness in your contracts, learn about Chainlink VRF.
And if you want your contracts to retrieve data from off-chain APIs, learn about Using Any API.
Testing Chainlink Contracts
See our blog post on Testing Chainlink Smart Contracts or watch the Chainlink Hackathon Workshop.
Tests samples can be found on Chainlink Hardhat Box and Chainlink Truffle Box respectively.
Updated 7 days ago
What's Next
Learn how to consume crypto prices, random numbers and how to call any API from your smart contracts
Introduction to Price Feeds |
Introduction to Chainlink VRF |
Introduction to Using Any API |