⚙️ How to Integrate QIE Oracle in Smart Contracts

Integrating QIE Oracle into your smart contract is simple and gas-efficient. The oracle contracts are read-only, meaning fetching data does not consume significant gas.

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✅ Integration Steps

1. Import the Oracle Interface

Use the standard AggregatorV3Interface, which is compatible with the QIE Oracle:

import "@chainlink/contracts/src/v0.8/interfaces/AggregatorV3Interface.sol";

This interface is supported because QIE Oracle follows the Chainlink AggregatorV3 standard.

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2. Instantiate the Oracle

Set the oracle contract address in your constructor or initializer:

AggregatorV3Interface public priceFeed;

constructor(address oracleAddress) {
    priceFeed = AggregatorV3Interface(oracleAddress);
}

Replace oracleAddress with the deployed address of the specific QIE Oracle for your asset (e.g., QIE/USD).

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3. Call latestRoundData() to Get the Price

Fetch the latest price in your contract logic:

function getLatestPrice() public view returns (int256) {
    (
        , 
        int256 price,
        , 
        , 
    ) = priceFeed.latestRoundData();

    return price;
}

This function is read-only (view) and consumes minimal gas when called externally or from another contract.

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⚡️ Gas Efficiency

All price-fetching functions on the QIE Oracle are non-state-changing (read-only). This means:

• No transaction needs to be sent

• No gas is spent reading data (unless used inside a transaction)

• Safe to use in frequent or lightweight calls