@hifi/protocol/README.md

The core Hifi fixed-rate, fixed-term lending protocol

# Hifi Protocol ![npm (scoped)](https://img.shields.io/npm/v/@hifi/protocol)

The core Hifi fixed-rate, fixed-term lending protocol. Hifi is a decentralized finance protocol that brings fixed-rate, fixed-term lending to Ethereum-based blockchains.

The build artifacts can be browsed via [unpkg.com](https://unpkg.com/browse/@hifi/protocol@latest/).

## Installation

With yarn:

```bash
$ yarn add @hifi/protocol
```

Or npm:

```bash
$ npm install @hifi/protocol
```

## Usage

The node package that you just installed contains both Solidity and JavaScript code. The former is the smart contracts
themselves; the latter, the smart contract ABIs and the TypeChain bindings.

### Solidity

The core Hifi protocol can only be compiled with Solidity v0.8.4 and above, because we are reverting with [custom
errors](https://blog.soliditylang.org/2021/04/21/custom-errors/) instead of reason strings.

```solidity
// SPDX-License-Identifier: Unlicense
pragma solidity >=0.8.4;

import "@hifi/protocol/contracts/core/balance-sheet/IBalanceSheetV2.sol";

contract YourContract {
    // Find the address on https://docs.hifi.finance
    IBalanceSheetV2 balanceSheet = IBalanceSheetV2(0x...);

    function queryAccountLiquidity(address user) external view returns (uint256 excessLiquidity, uint256 shortfallLiquidity) {
        (excessLiquidity, shortfallLiquidity) = balanceSheet.getCurrentAccountLiquidity(user);
    }

    function queryCollateralAmount(address user, IErc20 collateral) external view returns (uint256 collateralAmount) {
        collateralAmount = balanceSheet.getCollateralAmount(user, collateral);
    }

    function queryDebtAmount(address user, IHToken hToken) external view returns (uint256 debtAmount) {
        debtAmount = balanceSheet.getDebtAmount(user, hToken);
    }
}
```

### JavaScript

```javascript
import type { BalanceSheetV2__factory } from "@hifi/protocol/dist/types/factories/contracts/core/balance-sheet/BalanceSheetV2__factory";

async function queryAccountLiquidity() {
  const signer = "..."; // Get hold of an ethers.js Signer
  const balanceSheetFactory = new BalanceSheetV2__factory(signer); // Find the address on https://docs.hifi.finance
  const balanceSheet = balanceSheetFactory.attach("0x...");
  const user = "0x...";
  const accountLiquidity = await balanceSheet.getCurrentAccountLiquidity(user);
}
```

## Deployment

### Fintroller

```bash
$ yarn hardhat deploy:contract:fintroller \
    --new-owner ${NEW_OWNER} \
    --confirmations 5 \
    --network ${NETWORK} \
    --print true \
    --verify true
```

### Chainlink Operator

```bash
$ yarn hardhat deploy:contract:chainlink-operator \
    --new-owner ${NEW_OWNER} \
    --confirmations 5 \
    --network ${NETWORK} \
    --print true \
    --verify true
```

### Balance Sheet

```bash
$ yarn hardhat deploy:contract:balance-sheet \
    --fintroller ${FINTROLLER} \
    --oracle ${ORACLE} \
    --new-owner ${NEW_OWNER} \
    --confirmations 5 \
    --network ${NETWORK} \
    --print true \
    --verify true
```

### HToken

```bash
$ yarn hardhat deploy:contract:h-token \
    --name ${NAME} \
    --symbol ${SYMBOL} \
    --maturity ${MATURITY} \
    --balance-sheet ${BALANCE_SHEET} \
    --fintroller ${FINTROLLER} \
    --underlying ${UNDERLYING} \
    --confirmations 5 \
    --network ${NETWORK} \
    --print true \
    --verify true
```

### Simple Price Feed

```bash
$ yarn hardhat deploy:contract:simple-price-feed \
    --description ${DESCRIPTION} \
    --confirmations 5 \
    --network ${NETWORK} \
    --print true \
    --verify true
```

### Stablecoin Price Feed

```bash
$ yarn hardhat deploy:contract:stablecoin-price-feed \
    --price ${PRICE} \
    --description ${DESCRIPTION} \
    --confirmations 5 \
    --network ${NETWORK} \
    --print true \
    --verify true
```

### Uniswap V3 Price Feed

```bash
$ yarn hardhat deploy:contract:uniswap-v3-price-feed \
    --pool ${POOL} \
    --quoteAsset ${QUOTE_ASSET} \
    --twapInterval ${TWAP_INTERVAL} \
    --maxPrice ${MAX_PRICE} \
    --confirmations 5 \
    --network ${NETWORK} \
    --print true \
    --verify true
```

## License

[BUSL 1.1](./LICENSE.md) © Mainframe Group Inc.