hundred-dev

Overview

To deploy a new hToken (the Hundred Finance interest-bearing token), we need to:

1. Deploy a hToken contract.
2. Configure Chainlink oracle proxy.
3. Add the hToken to the money market.
4. Configure collateral factor.
5. Configure reserve factor.

1. Deploy a hToken contract

The contract to deploy is called a CErc20Delegator. Flatten source code: https://arbiscan.io/address/0xfcd8570ad81e6c77b8d252bebeba62ed980bd64d#code

• Compiler Version: v0.5.16+commit.9c3226ce
• Optimization Enabled: Yes with 200 runs

As example, we examin the process for hUSDC (Hundred USDC token) or Arbitrum.

{Constructor}

Parameters:

underlying_: The address of the underlying asset 0xff970a61a04b1ca14834a43f5de4533ebddb5cc8

comptroller_: The address of the Comptroller. 0x0f390559f258eb8591c8e31cf0905e97cf36ace2

interestRateModel_: The address of the interest rate model contract address. 0xe4e43864ea18d5e5211352a4b810383460ab7fcc

initialExchangeRateMantissa_: The initial exchange rate, scaled by 1e18. It is caculated as follows: 2 * 10^8 * 10^i where i is the number of decimals of the underlying asset of the hToken. (example: i = 6 for USDC, USDT, i = 6 for WBTC and i = 18 for main ERC20 tokens).

name_: ERC-20 name of this token. Hundred USDC

symbol_: ERC-20 symbol of this token. hUSDC

decimals_: ERC-20 decimal precision of this token. It is always 8. 8

admin_: Address of the administrator of this token. This address is set to the multi-signatures address. 0xb982841d8Caf7cCc1b5c8ec414347316F54A06c9

implementation_: The address of the implementation the contract delegates to. 0xbb93c7f378b9b531216f9ad7b5748be189a55807

becomeImplementationData: The encoded args for becomeImplementation. This value is unused. 0x0

2. Configure Chainlink oracle proxy

In order to consume the Price feeds from Chainlink, a ChainlinkPriceOracleProxy is deployed.

Next, the configuration settings are done, by calling the setTokenConfigs function on the ChainlinkPriceOracleProxy address.

Parameters:

chainlinkAggregatorAddress: The adress of the aggregator address as publised by Chainlink 0x50834F3163758fcC1Df9973b6e91f0F0F0434aD3

chainlinkPriceBase: This value is used to retrieve the asset price compared to either USD, ETH, BNB or WBTC 1

underlyingTokenDecimals: The number of the underlyingtoken. 6 in case of USDC

3. Add the hToken to the money market.

To add a market, its contract would need to be added to the Unitroller using the _supportMarket function. This function is available on the Comptroller, the Unitroller implementation.

To add the market,

Call the Unitroller by using its address. 0x0f390559f258eb8591c8e31cf0905e97cf36ace2

Use the comptroller ABI. To be copied from the network explorer like Arbiscan, Ftmscan...

Call the _supportMarket function.

Parameters:

Add the hToken address.

4. Config collateral factor

When the hToken has been added, the collaterFactor is to be set.

Call the Unitroller address and use the Comptroller ABI

Call function _setCollateralFactor

Parameters:

_ hToken: The market to set the factor on. _ newCollateralFactorMantissa: The new collateral factor, scaled by 1e18. 750000000000000000 as 75% for example.

5. Config reserve factor

The reserveFactor is set in the hToken contract

Call the hToken contract

Call the function _setReserveFactor

Parameters:

newReserveFactorMantissa: The new reserve factor, scaled by 1e18. 100000000000000000 as 10% for example.