smartcontractkit/defi-minimal

Defi Minimal

This repo is dedicated to making minimal repos of existing defi primatives.

Completed (but unreviewed) minimal contracts:

• Lending.sol: Based off Aave
• Staking.sol: Based off Synthetix
• RewardToken.sol: Based off Synthetix
• Exchange.sol , Factory.sol , Token.sol : Based off Uniswap v1. The used pricing formula is documented here
• DecentralizedStableCoin: Based off DAI
• CentralizedStableCoin: Based off USDC

Uncompleted:

• Options.sol: Based off nothing

Not a minimal contract:

• Swap.sol: Based off Uniswap - shows how a smart contract can integrate with a Uniswap-like dex.

Table Of Contents

• Defi Minimal
  • Completed (but unreviewed) minimal contracts:
  • Uncompleted:
  • Not a minimal contract:
• Table Of Contents
• Getting Started
  • Requirements
  • Quickstart
• Usage
  • Deploying Contracts
  • Run a Local Network
  • Using a Testnet or Live Network (like Mainnet or Polygon)
    • Rinkeby Ethereum Testnet Setup
• Code Formating
• Slither Static Analysis
• Contributing
• Thank You!
• Resources

Getting Started

It's recommended that you've gone through the hardhat getting started documentation before proceeding here.

Requirements

• git
  • You'll know you did it right if you can run git --version and you see a response like git version x.x.x
• Nodejs
  • You'll know you've installed nodejs right if you can run:
    • node --versionand get an ouput like: vx.x.x
• Yarn instead of npm
  • You'll know you've installed yarn right if you can run:
    • yarn --version And get an output like: x.x.x
    • You might need to install it with npm

If you're familiar with npx and npm instead of yarn, you can use npx for execution and npm for installing dependencies.

Quickstart

1. Clone and install dependencies

After installing all the requirements, run the following:

git clone https://github.com/smartcontractkit/defi-minimal/
cd defi-minimal

Then:

yarn

or

npm i

2. You can now do stuff!

yarn hardhat test

or

npx hardhat test

Usage

If you run yarn hardhat --help you'll get an output of all the tasks you can run.

Deploying Contracts

yarn hardhat deploy

This will deploy your contracts to a local network. Additionally, if on a local network, it will deploy mock Chainlink contracts for you to interact with. If you'd like to interact with your deployed contracts, skip down to Interacting with Deployed Contracts.

Run a Local Network

One of the best ways to test and interact with smart contracts is with a local network. To run a local network with all your contracts in it, run the following:

yarn hardhat node

You'll get a local blockchain, private keys, contracts deployed (from the deploy folder scripts), and an endpoint to potentially add to an EVM wallet.

Using a Testnet or Live Network (like Mainnet or Polygon)

In your hardhat.config.js you'll see section like:

module.exports = {
  defaultNetwork: "hardhat",
  networks: {

This section of the file is where you define which networks you want to interact with. You can read more about that whole file in the hardhat documentation.

To interact with a live or test network, you'll need:

1. An rpc URL
2. A Private Key
3. ETH & LINK token (either testnet or real)

Let's look at an example of setting these up using the Rinkeby testnet.

Rinkeby Ethereum Testnet Setup

First, we will need to set environment variables. We can do so by setting them in our .env file (create it if it's not there). You can also read more about environment variables from the linked twilio blog. You'll find a sample of what this file will look like in .env.example

IMPORTANT: MAKE SURE YOU'D DONT EXPOSE THE KEYS YOU PUT IN THIS .env FILE. By that, I mean don't push them to a public repo, and please try to keep them keys you use in development not associated with any real funds.

1. Set your RINKEBY_RPC_URL environment variable.

You can get one for free from Alchmey, Infura, or Moralis. This is your connection to the blockchain.

2. Set your PRIVATE_KEY environment variable.

This is your private key from your wallet, ie MetaMask. This is needed for deploying contracts to public networks. You can optionally set your MNEMONIC environment variable instead with some changes to the hardhat.config.js.

WARNING

When developing, it's best practice to use a Metamask that isn't associated with any real money. A good way to do this is to make a new browser profile (on Chrome, Brave, Firefox, etc) and install Metamask on that brower, and never send this wallet money.

Don't commit and push any changes to .env files that may contain sensitive information, such as a private key! If this information reaches a public GitHub repository, someone can use it to check if you have any Mainnet funds in that wallet address, and steal them!

.env example:

RINKEBY_RPC_URL='www.infura.io/asdfadsfafdadf'
PRIVATE_KEY='abcdef'

bash example

export RINKEBY_RPC_URL='www.infura.io/asdfadsfafdadf'
export PRIVATE_KEY='abcdef'

You can also use a MNEMONIC instead of a PRIVATE_KEY environment variable by uncommenting the section in the hardhat.config.js, and commenting out the PRIVATE_KEY line. However this is not recommended.

For other networks like mainnet and polygon, you can use different environment variables for your RPC URL and your private key. See the hardhat.config.js to learn more.

3. Get some Rinkeby Testnet ETH and LINK

Head over to the Chainlink faucets and get some ETH and LINK. Please follow the chainlink documentation if unfamiliar.

Code Formating

This will format both your javascript and solidity to look nicer.

yarn format

Slither Static Analysis

You'll need python and slither installed.

yarn slither

Contributing

Contributions are always welcome! Open a PR or an issue!

Thank You!

Resources

• Chainlink Documentation
• Hardhat Documentation
• Solidity by Example