Use API3 To Request Off-Chain Data on Moonbeam¶

// SPDX-License-Identifier: MIT
pragma solidity 0.8.9;

import "@api3/airnode-protocol/contracts/rrp/requesters/RrpRequesterV0.sol";
import "@openzeppelin/contracts@4.9.5/access/Ownable.sol";

// A Requester that will return the requested data by calling the specified Airnode.
contract Requester is RrpRequesterV0, Ownable {
    mapping(bytes32 => bool) public incomingFulfillments;
    mapping(bytes32 => int256) public fulfilledData;

    // Make sure you specify the right _rrpAddress for your chain while deploying the contract.
    constructor(address _rrpAddress) RrpRequesterV0(_rrpAddress) {}

    // To receive funds from the sponsor wallet and send them to the owner.
    receive() external payable {
        payable(owner()).transfer(address(this).balance);
    }

    // The main makeRequest function that will trigger the Airnode request.
    function makeRequest(
        address airnode,
        bytes32 endpointId,
        address sponsor,
        address sponsorWallet,
        bytes calldata parameters

    ) external {
        bytes32 requestId = airnodeRrp.makeFullRequest(
            airnode,                        // airnode address
            endpointId,                     // endpointId
            sponsor,                        // sponsor's address
            sponsorWallet,                  // sponsorWallet
            address(this),                  // fulfillAddress
            this.fulfill.selector,          // fulfillFunctionId
            parameters                      // encoded API parameters
        );
        incomingFulfillments[requestId] = true;
    }

    function fulfill(bytes32 requestId, bytes calldata data)
        external
        onlyAirnodeRrp
    {
        require(incomingFulfillments[requestId], "No such request made");
        delete incomingFulfillments[requestId];
        int256 decodedData = abi.decode(data, (int256));
        fulfilledData[requestId] = decodedData;
    }

    // To withdraw funds from the sponsor wallet to the contract.
    function withdraw(address airnode, address sponsorWallet) external onlyOwner {
        airnodeRrp.requestWithdrawal(
        airnode,
        sponsorWallet
        );
    }
}

// SPDX-License-Identifier: MIT
pragma solidity 0.8.17;

import "@openzeppelin/contracts@4.9.5/access/Ownable.sol";
import "@api3/contracts/api3-server-v1/proxies/interfaces/IProxy.sol";

contract DataFeedReaderExample is Ownable {
    // The proxy contract address obtained from the API3 Market UI
    address public proxyAddress;

    // Updating the proxy contract address is a security-critical
    // action. In this example, only the owner is allowed to do so
    function setProxyAddress(address _proxyAddress) public onlyOwner {
        proxyAddress = _proxyAddress;
    }

    function readDataFeed()
        external
        view
        returns (int224 value, uint256 timestamp)
    {
        // Use the IProxy interface to read a dAPI via its
        // proxy contract
        (value, timestamp) = IProxy(proxyAddress).read();
        // If you have any assumptions about `value` and `timestamp`,
        // make sure to validate them after reading from the proxy
    }
}

//SPDX-License-Identifier: MIT
pragma solidity 0.8.9;

import "@api3/airnode-protocol/contracts/rrp/requesters/RrpRequesterV0.sol";
import "@openzeppelin/contracts@4.9.5/access/Ownable.sol";

/// @title Example contract that uses Airnode RRP to access QRNG services
contract QrngExample is RrpRequesterV0, Ownable {
    event RequestedUint256(bytes32 indexed requestId);
    event ReceivedUint256(bytes32 indexed requestId, uint256 response);
    event RequestedUint256Array(bytes32 indexed requestId, uint256 size);
    event ReceivedUint256Array(bytes32 indexed requestId, uint256[] response);
    event WithdrawalRequested(address indexed airnode, address indexed sponsorWallet);

    address public airnode;                 /// The address of the QRNG Airnode
    bytes32 public endpointIdUint256;       /// The endpoint ID for requesting a single random number
    bytes32 public endpointIdUint256Array;  /// The endpoint ID for requesting an array of random numbers
    address public sponsorWallet;           /// The wallet that will cover the gas costs of the request
    uint256 public _qrngUint256;            /// The random number returned by the QRNG Airnode
    uint256[] public _qrngUint256Array;     /// The array of random numbers returned by the QRNG Airnode

    mapping(bytes32 => bool) public expectingRequestWithIdToBeFulfilled;

    constructor(address _airnodeRrp) RrpRequesterV0(_airnodeRrp) {}

    /// @notice Sets the parameters for making requests
    function setRequestParameters(
        address _airnode,
        bytes32 _endpointIdUint256,
        bytes32 _endpointIdUint256Array,
        address _sponsorWallet
    ) external {
        airnode = _airnode;
        endpointIdUint256 = _endpointIdUint256;
        endpointIdUint256Array = _endpointIdUint256Array;
        sponsorWallet = _sponsorWallet;
    }

    /// @notice To receive funds from the sponsor wallet and send them to the owner.
    receive() external payable {
        payable(owner()).transfer(msg.value);
        emit WithdrawalRequested(airnode, sponsorWallet);
    }

    /// @notice Requests a `uint256`
    /// @dev This request will be fulfilled by the contract's sponsor wallet,
    /// which means spamming it may drain the sponsor wallet.
    function makeRequestUint256() external {
        bytes32 requestId = airnodeRrp.makeFullRequest(
            airnode,
            endpointIdUint256,
            address(this),
            sponsorWallet,
            address(this),
            this.fulfillUint256.selector,
            ""
        );
        expectingRequestWithIdToBeFulfilled[requestId] = true;
        emit RequestedUint256(requestId);
    }

    /// @notice Called by the Airnode through the AirnodeRrp contract to
    /// fulfill the request
    function fulfillUint256(bytes32 requestId, bytes calldata data)
        external
        onlyAirnodeRrp
    {
        require(
            expectingRequestWithIdToBeFulfilled[requestId],
            "Request ID not known"
        );
        expectingRequestWithIdToBeFulfilled[requestId] = false;
        uint256 qrngUint256 = abi.decode(data, (uint256));
        _qrngUint256 = qrngUint256;
        // Do what you want with `qrngUint256` here...
        emit ReceivedUint256(requestId, qrngUint256);
    }

    /// @notice Requests a `uint256[]`
    /// @param size Size of the requested array
    function makeRequestUint256Array(uint256 size) external {
        bytes32 requestId = airnodeRrp.makeFullRequest(
            airnode,
            endpointIdUint256Array,
            address(this),
            sponsorWallet,
            address(this),
            this.fulfillUint256Array.selector,
            // Using Airnode ABI to encode the parameters
            abi.encode(bytes32("1u"), bytes32("size"), size)
        );
        expectingRequestWithIdToBeFulfilled[requestId] = true;
        emit RequestedUint256Array(requestId, size);
    }

    /// @notice Called by the Airnode through the AirnodeRrp contract to
    /// fulfill the request
    function fulfillUint256Array(bytes32 requestId, bytes calldata data)
        external
        onlyAirnodeRrp
    {
        require(
            expectingRequestWithIdToBeFulfilled[requestId],
            "Request ID not known"
        );
        expectingRequestWithIdToBeFulfilled[requestId] = false;
        uint256[] memory qrngUint256Array = abi.decode(data, (uint256[]));
        // Do what you want with `qrngUint256Array` here...
        _qrngUint256Array = qrngUint256Array;
        emit ReceivedUint256Array(requestId, qrngUint256Array);
    }

    /// @notice Getter functions to check the returned value.
    function getRandomNumber() public view returns (uint256) {
        return _qrngUint256;
    }

    function getRandomNumberArray() public view returns(uint256[] memory) {
        return _qrngUint256Array;
    }

    /// @notice To withdraw funds from the sponsor wallet to the contract.
    function withdraw() external onlyOwner {
        airnodeRrp.requestWithdrawal(
        airnode,
        sponsorWallet
        );
    }
}