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Chronicle Protocol is a novel Oracle solution that has exclusively secured over $10B in assets for MakerDAO and its ecosystem since 2017. Chronicle overcomes the current limitations of transferring data on-chain by developing scalable, cost-efficient, decentralized, and verifiable Oracles, rewriting the rulebook on data transparency and accessibility.

Querying the price of GNO using Chronicle

Chronicle contracts are read-protected by a whitelist, meaning you won't be able to read them on-chain without your address being added to the whitelist. On the Testnet, users can add themselves to the whitelist through the SelfKisser contract, a process playfully referred to as "kissing" themselves. For access to production Oracles on the Mainnet, please open a support ticket on Discord in the 🆘|support channel.

For the deployment addresses, please check out the Dashboard.

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

* @title OracleReader
* @notice A simple contract to read from Chronicle oracles
* @dev To see the full repository, visit
* @dev Addresses in this contract are hardcoded for Gnosis.
* For other supported networks, check the
contract OracleReader {
* @notice The Chronicle oracle to read from.
* GNO/USD - Chronicle_GNO_USD_2 - 0xBcC6BFFde7888A3008f17c88D5a5e5F0D7462cf9
* Network: Gnosis

IChronicle public chronicle = IChronicle(address(0xBcC6BFFde7888A3008f17c88D5a5e5F0D7462cf9));

* @notice The SelfKisser granting access to Chronicle oracles.
* SelfKisser_1:0x0Dcc19657007713483A5cA76e6A7bbe5f56EA37d
* Network: Gnosis
ISelfKisser public selfKisser = ISelfKisser(address(0x0Dcc19657007713483A5cA76e6A7bbe5f56EA37d));

constructor() {
// Note to add address(this) to chronicle oracle's whitelist.
// This allows the contract to read from the chronicle oracle.

* @notice Function to read the latest data from the Chronicle oracle.
* @return val The current value returned by the oracle.
* @return age The timestamp of the last update from the oracle.
function read() external view returns (uint256 val, uint256 age) {
(val, age) = chronicle.readWithAge();

// Copied from [chronicle-std](
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);

* @notice Returns the oracle's current value and its age.
* @dev Reverts if no value set.
* @return value The oracle's current value using 18 decimals places.
* @return age The value's age as a Unix Timestamp .
* */
function readWithAge() external view returns (uint256 value, uint256 age);

// Copied from [self-kisser](
interface ISelfKisser {
/// @notice Kisses caller on oracle `oracle`.
function selfKiss(address oracle) external;

More examples

For more examples on integrating Chronicle Oracles, please check the documentation portal.

Get in touch

If you have any questions or need support, drop us a message on Discord.