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This repository contains the smart contracts source code and markets configuration for Bend Protocol. The repository uses Hardhat as development enviroment for compilation, testing and deployment tasks.

Bend is a decentralized non-custodial NFT lending protocol where users can participate as depositors or borrowers. Depositors provide liquidity to the market to earn a passive income, while borrowers are able to borrow in an overcollateralized fashion, using NFTs as collaterl.

The documentation of Bend Protocol is in the following Bend documentation link. At the documentation you can learn more about the protocol, see the contract interfaces, integration guides and audits.

For getting the latest contracts addresses, please check the Deployed contracts page at the documentation to stay up to date.

Certik Online Report.

You can join at the Discord channel or at the Governance for asking questions about the protocol or talk about Bend with other peers.

You can install @benddao/bend-protocol as an NPM package in your Hardhat, Buidler or Truffle project to import the contracts and interfaces:

npm install @benddao/bend-protocol

Import at Solidity files:

import {ILendPool} from "@benddao/bend-protocol/contracts/interfaces/ILendPool.sol";

contract Misc {

  function deposit(address pool, address token, address user, uint256 amount) public {
    ILendPool(pool).deposit(token, amount, user, 0);
    {...}
  }
}

The JSON artifacts with the ABI and Bytecode are also included into the bundled NPM package at artifacts/ directory.

Import JSON file via Node JS require:

const LendPoolArtifact = require('@benddao/bend-protocol/artifacts/contracts/protocol/LendPool.sol/LendPool.json');

// Log the ABI into console
console.log(LendPoolArtifact.abi)

The repository uses Docker Compose to manage sensitive keys and load the configuration. Prior any action like test or deploy, you must run docker-compose up to start the contracts-env container, and then connect to the container console via docker-compose exec contracts-env bash.

Follow the next steps to setup the repository:

• Install docker and docker-compose
• Create an enviroment file named .env and fill the next enviroment variables

# Mnemonic, only first address will be used
MNEMONIC=""

# Add Alchemy or Infura provider keys, alchemy takes preference at the config level
ALCHEMY_KEY=""
INFURA_KEY=""

# Optional Etherscan key, for automatize the verification of the contracts at Etherscan
ETHERSCAN_KEY=""

The configurations related with the Bend Markets are located at markets directory. You can follow the IBendConfiguration interface to create new Markets configuration or extend the current Bend configuration.

Each market should have his own Market configuration file, and their own set of deployment tasks, using the Bend market config and tasks as a reference.

You can run the full test suite with the following commands:

# In one terminal
docker-compose up

# Open another tab or terminal
docker-compose exec contracts-env bash

# install dependencies
yarn install

# A new Bash terminal is prompted, connected to the container
npm run test

For deploying Bend Protocol, you can use the available scripts located at package.json. For a complete list, run npm run to see all the tasks.

# In one terminal
docker-compose up

# Open another tab or terminal
docker-compose exec contracts-env bash

# install dependencies
yarn install

# Runing NPM task
# npm run xxx

# In first terminal
npm run hardhat:node

# In second terminal
npm run bend:localhost:dev:migration

# In first terminal
npm run hardhat:node

# In second terminal
npx hardhat --network localhost "dev:deploy-mock-reserves"
# then update pool config reserve address

npx hardhat --network localhost "dev:deploy-mock-nfts"
# then update pool config nft address

npx hardhat --network localhost "dev:deploy-mock-aggregators" --pool Bend
# then update pool config reserve aggregators address

npx hardhat --network localhost "dev:deploy-mock-bnft-registry" --pool Bend
# then update pool config bnft registry address

npx hardhat --network localhost "dev:deploy-mock-bnft-tokens" --pool Bend

# In one terminal
npm run bend:rinkeby:full:migration

You can interact with Bend at Mainnet network using the Hardhat console, in the scenario where the frontend is down or you want to interact directly. You can check the deployed addresses at deployed-contracts.

Run the Hardhat console pointing to the Mainnet network:

npx hardhat --network main console

At the Hardhat console, you can interact with the protocol:

// Load the HRE into helpers to access signers
run("set-DRE")

// Import getters to instance any Bend contract
const contractGetters = require('./helpers/contracts-getters');

// Load the first signer
const signer = await contractGetters.getFirstSigner();

// Lend pool instance
const lendPool = await contractGetters.getLendPool("0x3AF6fC17EbD751E4D11F5A1d6823b2aE64723B87");

// ERC20 token WETH Mainnet instance
const WETH = await contractGetters.getIErc20Detailed("0xbe4d36E2C69Aa9658e937f6cC584E60167484381");

// Approve 10 WETH to LendPool address
await WETH.connect(signer).approve(lendPool.address, ethers.utils.parseUnits('10'));

// Deposit 10 WETH
await lendPool.connect(signer).deposit(DAI.address, ethers.utils.parseUnits('10'), await signer.getAddress(), '0');

This project integrates other tools commonly used alongside Hardhat in the ecosystem.

It also comes with a variety of other tools, preconfigured to work with the project code.

Try running some of the following tasks:

npx hardhat accounts
npx hardhat compile
npx hardhat clean
npx hardhat test
npx hardhat node
npx hardhat help
REPORT_GAS=true npx hardhat test
npx hardhat coverage
npx hardhat run scripts/deploy.js
node scripts/deploy.js
npx eslint '**/*.js'
npx eslint '**/*.js' --fix
npx prettier '**/*.{json,sol,md}' --check
npx prettier '**/*.{json,sol,md}' --write
npx solhint 'contracts/**/*.sol'
npx solhint 'contracts/**/*.sol' --fix

To try out Etherscan verification, you first need to deploy a contract to an Ethereum network that's supported by Etherscan, such as Ropsten.

In this project, copy the .env.template file to a file named .env, and then edit it to fill in the details. Enter your Etherscan API key, your Ropsten node URL (eg from Alchemy), and the private key of the account which will send the deployment transaction. With a valid .env file in place, first deploy your contract:

hardhat run --network ropsten scripts/deploy.js

Then, copy the deployment address and paste it in to replace DEPLOYED_CONTRACT_ADDRESS in this command:

npx hardhat verify --network ropsten DEPLOYED_CONTRACT_ADDRESS "Hello, Hardhat!"