Merge pull request 0xPolygon#568 from biancabuzea200/main

Add Chronicle to Oracles list

Author: hsutaiyu

docs/tools/oracles/chronicle.md

@@ -0,0 +1,83 @@
+!!! info "Content disclaimer"
+
+    Please view the third-party content disclaimer [here](https://github.com/0xPolygon/polygon-docs/blob/main/CONTENT_DISCLAIMER.md).
+
+## Chronicle  
+
+[Chronicle Protocol](https://chroniclelabs.org/) 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 MATIC 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](https://discord.com/invite/CjgvJ9EspJ) in the 🆘｜support channel.
+
+For the deployment addresses, please check out the [Dashboard](https://chroniclelabs.org/dashboard/oracles). 
+```solidity
+// 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 https://github.com/chronicleprotocol/OracleReader-Example.
+ * @dev Addresses in this contract are hardcoded for the zkEVM Testnet.
+ * For other supported networks, check the https://chroniclelabs.org/dashboard/oracles.
+ */
+contract OracleReader {
+    /**
+    * @notice The Chronicle oracle to read from.
+    * Chronicle_MATIC_USD_1 - 0x55a07a60cd9ed198B5Ba4360FF9800eBb6667388
+    * Network: zkEVM Testnet
+    */
+
+    IChronicle public chronicle = IChronicle(address(0x55a07a60cd9ed198B5Ba4360FF9800eBb6667388));
+
+    /** 
+    * @notice The SelfKisser granting access to Chronicle oracles.
+    * SelfKisser_1:0x0Dcc19657007713483A5cA76e6A7bbe5f56EA37d
+    * Network: zkEVM Testnet
+    */
+    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.
+        selfKisser.selfKiss(address(chronicle));
+    }
+
+    /** 
+    * @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](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);
+
+    /** 
+    * @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](https://github.com/chronicleprotocol/self-kisser/blob/main/src/ISelfKisser.sol).
+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](https://docs.chroniclelabs.org/). 
+
+    

mkdocs.yml

@@ -519,6 +519,7 @@ nav:
           - Bandchain: tools/oracles/bandchain.md
           - Band standard dataset: tools/oracles/bandstandarddataset.md
           - Chainlink: tools/oracles/chainlink.md
+          - Chronicle: tools/oracles/chronicle.md
           - DIA: tools/oracles/diadataoracles.md
           - Pyth: tools/oracles/pyth.md
           - Razor: tools/oracles/razor.md