Venus Protocol

The Venus Protocol is an Binance Smart Chain smart contract for supplying or borrowing assets. Through the vToken contracts, accounts on the blockchain supply capital (BNB or BEP-20 tokens) to receive vTokens or borrow assets from the protocol (holding other assets as collateral). The protocol will also enable the minting of VAI, which is the first synthetic stablecoin on Venus that aims to be pegged to 1 USD. VAI is minted by the same collateral that is supplied to the protocol. The Venus vToken contracts track these balances and algorithmically set interest rates for borrowers.

Before getting started with this repo, please read:

• Venus Whitepaper

Interested in contributing? Please checkout our contributing guidelines

Contracts

We detail a few of the core contracts in the Venus protocol.

VToken, VBep20 and VBNB

The Venus vTokens, which are self-contained borrowing and lending contracts. VToken contains the core logic and VBep20, VBUSD, VSXP and VBNB add public interfaces for Bep20 tokens and bnb, respectively. Each VToken is assigned an interest rate and risk model (see InterestRateModel and Comptroller sections), and allows accounts to *mint* (supply capital), *redeem* (withdraw capital), *borrow* and *repay a borrow*. Each VToken is an BEP-20 compliant token where balances represent ownership of the market.

Comptroller

The risk model contract, which validates permissible user actions and disallows actions if they do not fit certain risk parameters. For instance, the Comptroller enforces that each borrowing user must maintain a sufficient collateral balance across all vTokens.

XVS

The Venus Governance Token (XVS). Holders of this token have the ability to govern the protocol via the governor contract.

SXP

The Venus Governance Token (SXP). Holders of this token have the ability to govern the protocol via the governor contract.

Governor Alpha

The administrator of the Venus timelock contract. Holders of XVS(SXP) token may create and vote on proposals which will be queued into the Venus timelock and then have effects on Venus vToken and Comptroller contracts. This contract may be replaced in the future with a beta version.

InterestRateModel

Contracts which define interest rate models. These models algorithmically determine interest rates based on the current utilization of a given market (that is, how much of the supplied assets are liquid versus borrowed).

Careful Math

Library for safe math operations.

ErrorReporter

Library for tracking error codes and failure conditions.

Exponential

Library for handling fixed-point decimal numbers.

SafeToken

Library for safely handling Bep20 interaction.

WhitePaperInterestRateModel

Initial interest rate model, as defined in the Whitepaper. This contract accepts a base rate and slope parameter in its constructor.

Documentation

Documentation is autogenerated using solidity-docgen. They can be generated by running yarn docgen

Installation

To run venus, pull the repository from GitHub and install its dependencies. You will need yarn or npm installed.

git clone https://github.com/VenusProtocol/venus-protocol
cd venus-protocol
yarn install --lock-file # or `npm install`

Solidity Compiler Installation on MacOS

• Solidity smart contracts in venus-protocol use solc version 0.5.16

• To install solidity compiler solc, follow the instructions listed here:

  1. clone homebrew-ethereum project that provides homebrew formulae for solc:

  git clone git@github.com:ethereum/homebrew-ethereum.git

  2. change to project directory

    cd homebrew-ethereum

  3. checkout the commit hash for version 0.5.16

    git checkout 5df4d76a780813a0ad625619572afb358d46c1d4

  4. Install compiler version 0.5.16 by executing command

    brew install solidity@5

  5. Verify the installed solidity version

    solc --version

  • the command should print the console log:

  solc, the solidity compiler commandline interface
  Version: 0.5.16+commit.9c3226ce.Darwin.appleclang
  

Testing

Jest contract tests are defined under the tests directory. To run the tests run:

yarn test

Integration Specs

There are additional tests under the spec/scenario folder. These are high-level integration tests based on the scenario runner depicted above. The aim of these tests is to be highly literate and have high coverage in the interaction of contracts.

Formal Verification Specs

The Venus Protocol has a number of formal verification specifications, powered by Certik. The Certik Verification evaluates smart contracts for vulnerabilities and certifies their behavior with respect to a custom function specification.

Testing

Contract tests are defined under the tests directory. To run the tests run:

yarn test

• To run fork tests add FORK_MAINNET=true and BSC_ARCHIVE_NODE_URL in the .env file.

Code Coverage

To run code coverage, run:

npx hardhat coverage

Deployment

npx hardhat deploy

• This command will execute all the deployment scripts in ./deploy directory - It will skip only deployment scripts which implement a skip condition - Here is example of a skip condition: - Skipping deployment script on bsctestnet network func.skip = async (hre: HardhatRuntimeEnvironment) => hre.network.name !== "bsctestnet";
• The default network will be hardhat
• Deployment to another network: - Make sure the desired network is configured in hardhat.config.ts - Add MNEMONIC variable in .env file - Execute deploy command by adding --network <network_name> in the deploy command above - E.g. npx hardhat deploy --network bsctestnet
• Execution of single or custom set of scripts is possible, if:
  • In the deployment scripts you have added tags for example: - func.tags = ["MockTokens"];
  • Once this is done, adding --tags "<tag_name>,<tag_name>..." to the deployment command will execute only the scripts containing the tags.

Source Code Verification

In order to verify the source code of already deployed contracts, run: npx hardhat etherscan-verify --network <network_name>

Make sure you have added ETHERSCAN_API_KEY in .env file.

Linting

To lint the code, run:

yarn lint

To format the code, run: yarn prettier

Hardhat Commands

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

TS_NODE_FILES=true npx ts-node scripts/deploy.ts

npx eslint '**/*.{js,ts}'

npx eslint '**/*.{js,ts}' --fix

npx prettier '**/*.{json,sol,md}' --check

npx prettier '**/*.{json,sol,md}' --write

npx solhint 'contracts/**/*.sol'

npx solhint 'contracts/**/*.sol' --fix



MNEMONIC="<>" BSC_API_KEY="<>" npx hardhat run ./script/hardhat/deploy.ts --network testnet

Discussion

For any concerns with the protocol, open an issue or visit us on Telegram to discuss.

For security concerns, please contact the administrators of our telegram chat.

© Copyright 2021, Venus Protocol