Automate any smart contract—up to 1/10th the gas cost

struct Log {
    uint256 index;
    uint256 timestamp;
    bytes32 txHash;
    uint256 blockNumber;
    bytes32 blockHash;
    address source;
    bytes32[] topics;
    bytes data;
}

function checkLog(Log calldata log, bytes memory) external view returns (bool upkeepNeeded, bytes memory performData)
  {
    // Define the log that triggers your upkeep during the registration process
    // Once detected, checkLog will run
    // Use the data from the log here!
    return (true, performData)
  }

function performUpkeep(bytes calldata performData) external override 
  {
    //On chain transaction logic
  }

function checkLog(Log calldata log, bytes memory)
        external
        view
        returns (bool upkeepNeeded, bytes memory performData)
    {
        // The StreamsLookup revert message tells the Chainlink DON to go retrieve Data Streams data
        revert StreamsLookup(
            STRING_DATASTREAMS_FEEDLABEL,
            ARRAY_OF_FEED_IDS,
            STRING_DATASTREAMS_QUERYLABEL,
            log.timestamp,
            extraData
        );
    }

// The data retrieved after StreamsLookup is called is passed into checkCallback
function checkCallback(bytes[] calldata values, bytes calldata extraData)
        external
        pure
        returns (bool, bytes memory)
    {
        return (true, abi.encode(values, extraData));
    } 
    
// if checkCallback returns true, the price data is passed to performUpkeep for an on chain transaction
function performUpkeep(bytes calldata performData) external override {
        (bytes[] memory signedReports, bytes memory extraData) = abi.decode(
            performData,
            (bytes[], bytes)
        );	
	bytes reportData = verifier.verify(signedReports[0]);
	// Use signedReports as need to complete your transaction with price data
    }