Skip to main content

OracleReader

The OracleReader contract aggregates price feeds from Chainlink oracles to provide accurate token valuations for collateral calculations, health factor monitoring, and liquidation decisions.

Overview​

  • Pattern: UUPS Upgradeable Proxy
  • Solidity Version: 0.8.24
  • Dependencies: OpenZeppelin Contracts v5, Chainlink v0.8

Key Functions​

getPrice​

function getPrice(address token) external view returns (uint256 price, uint8 decimals)

Returns the latest price for a token in USD.

Parameters:

  • token -- ERC-20 token address

Returns:

  • price -- Token price in USD (scaled by decimals)
  • decimals -- Number of decimal places in the price

getHealthFactor​

function getHealthFactor(address user) external view returns (uint256)

Calculates the health factor for a user by comparing their weighted collateral value against their outstanding credit balance.

Returns: Health factor scaled to 18 decimals (1e18 = 1.0)

getCollateralValue​

function getCollateralValue(address user) external view returns (uint256)

Returns the total USD value of a user's deposits weighted by collateral factors.

Price Feed Configuration​

TokenChainlink FeedHeartbeat
ETHETH/USD1 hour
USDCUSDC/USD24 hours
USDTUSDT/USD24 hours
DAIDAI/USD1 hour
wstETHwstETH/USD24 hours

Staleness Checks​

The contract enforces staleness thresholds on all price feeds:

require(
    block.timestamp - updatedAt <= stalePriceThreshold,
    "Price feed is stale"
);

If a price feed is stale, the transaction will revert rather than use outdated data.

Deviation Checks​

Large price deviations between consecutive updates trigger additional validation:

if (deviation > maxDeviation) {
    // Fall back to TWAP or revert
}

Adding Price Feeds​

function setPriceFeed(
    address token,
    address feed,
    uint256 staleThreshold
) external onlyOwner

New price feeds are configured by the contract owner. Each feed must be a valid Chainlink AggregatorV3Interface.

Security Considerations​

  • Staleness checks prevent using outdated prices
  • Deviation checks catch oracle manipulation attempts
  • Multiple independent price sources reduce single-point-of-failure risk
  • Emergency price override available for owner in extreme market conditions

Next Steps​