Boilerplate

Scaffold-ETH2 + Chronicle

info

Please be aware that, as the project currently stands, you should use Foundry in terms of programming environments, and deploy your contracts to the Sepolia network.

Please refer to the following GitHub Repo to take advantage of the boilerplate we have created in conjunction with Scaffold-ETH2.

To find our OracleReader.sol contract, follow the following path:

- packages
    - foundry
        - contracts
            - OracleReader.sol

Below is an example of the contract integrated into the repo:

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.16;

/**
 * @title OracleReader
 * @notice A simple contract to read from Chronicle oracles
 * @dev Addresses in this contract are hardcoded for the Sepolia testnet.
 * For other supported networks, check https://chroniclelabs.org/dashboard/oracles.
 */
contract OracleReader {
    ///  @notice The Chronicle ETH/USD oracle.
    IChronicle public immutable chronicle;

    /// @notice The SelfKisser granting access to Chronicle oracles.
    ISelfKisser public immutable selfKisser;

    constructor(address chronicle_, address selfKisser_) {
        chronicle = IChronicle(chronicle_);
        selfKisser = ISelfKisser(selfKisser_);

        // Note to add address(this) to chronicle oracle's whitelist.
        // This allows the contract to read from the chronicle oracle.
        selfKisser.selfKiss(address(chronicle));
    }

    /// @notice Function to read the latest data from the Chronicle oracle.
    /// @return val The current value returned by the oracle.
    function read() external view returns (uint256 val) {
        return chronicle.read();
    }
}

// Copied from [chronicle-std](https://github.com/chronicleprotocol/chronicle-std/blob/main/src/IChronicle.sol).
interface IChronicle {
    /**
     * @notice Returns the oracle's current value.
     * @dev Reverts if no value set.
     * @return value The oracle's current value.
     * /
    function read() external view returns (uint256 value);
}

// Copied from [self-kisser](https://github.com/chronicleprotocol/self-kisser/blob/main/src/ISelfKisser.sol).
interface ISelfKisser {
    /// @notice Kisses caller on oracle `oracle`.
    function selfKiss(address oracle) external;
}

Add your environment variables in the .env.example file and rename it to .env:

- packages
    - foundry
         - .env.example

/* 
* Template for environment variables.
* To use this template, copy this file, rename it .env, and fill in the values.
* The Chronicle ETH/USD Oracle on Sepolia.
*/

DEPLOYER_PRIVATE_KEY=
ETHERSCAN_API_KEY=
ALCHEMY_API_KEY=

# The Chronicle ETH/USD Oracle on Sepolia.
CHRONICLE_ORACLE=0xdd6D76262Fd7BdDe428dcfCd94386EbAe0151603
# The Chronicle SelfKisser contract on Sepolia.
SELF_KISSER=0x0Dcc19657007713483A5cA76e6A7bbe5f56EA37d