diff --git a/.gitmodules b/.gitmodules
index a6260fb..899b5ab 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -4,3 +4,9 @@
 [submodule "lib/create3-deploy"]
 	path = lib/create3-deploy
 	url = https://github.com/darwinia-network/create3-deploy
+[submodule "lib/xapi-contracts"]
+	path = lib/xapi-contracts
+	url = https://github.com/ringecosystem/xapi-contracts
+[submodule "lib/chainlink"]
+	path = lib/chainlink
+	url = https://github.com/smartcontractkit/chainlink
diff --git a/lib/chainlink b/lib/chainlink
new file mode 160000
index 0000000..fb7d6e8
--- /dev/null
+++ b/lib/chainlink
@@ -0,0 +1 @@
+Subproject commit fb7d6e88ea3471909a4f9aa29992ec080bba9057
diff --git a/lib/xapi-contracts b/lib/xapi-contracts
new file mode 160000
index 0000000..92466ba
--- /dev/null
+++ b/lib/xapi-contracts
@@ -0,0 +1 @@
+Subproject commit 92466ba49ce1bf1c0b8ef4f846d20923cd70183c
diff --git a/remappings.txt b/remappings.txt
index c7d2aae..25fb4ec 100644
--- a/remappings.txt
+++ b/remappings.txt
@@ -1,3 +1,6 @@
 forge-std/=lib/forge-std/src/
 ds-test/=lib/forge-std/lib/ds-test/src/
 create3-deploy/=lib/create3-deploy/
+xapi/=lib/xapi-contracts/xapi/
+xapi-consumer/=lib/xapi-contracts/xapi-consumer/contracts/
+@chainlink/=lib/chainlink/
diff --git a/src/eco/XAPIOracle.sol b/src/eco/XAPIOracle.sol
new file mode 100644
index 0000000..111ea0f
--- /dev/null
+++ b/src/eco/XAPIOracle.sol
@@ -0,0 +1,172 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.0;
+
+import "../Verifier.sol";
+import "../interfaces/IORMP.sol";
+import "xapi-consumer/interfaces/IXAPIConsumer.sol";
+import "xapi/contracts/lib/XAPIBuilder.sol";
+
+contract XAPIOracle is Verifier, IXAPIConsumer {
+    using XAPIBuilder for XAPIBuilder.Request;
+
+    event SetFee(uint256 indexed chainId, uint256 fee);
+    event SetApproved(address operator, bool approve);
+    event Withdrawal(address indexed to, uint256 amt);
+    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
+    event XAPIRequestMade(uint256 indexed requestId, XAPIBuilder.Request requestData);
+    event XAPIConsumeResult(uint256 indexed requestId, bytes responseData, uint16 errorCode);
+    event XAPIConsumeError(uint256 indexed requestId, uint16 errorCode);
+
+    address public immutable PROTOCOL;
+    address public immutable XAPI;
+    address public immutable EXAGGREGATOR;
+
+    address public owner;
+    // chainId => price
+    mapping(uint256 => uint256) public feeOf;
+    // operator => isApproved
+    mapping(address => bool) public approvedOf;
+
+    struct DataSource {
+        string name;
+        string url;
+        string method;
+        string resultPath;
+    }
+
+    uint256 requestId;
+
+    modifier onlyOwner() {
+        require(msg.sender == owner, "!owner");
+        _;
+    }
+
+    modifier onlyXAPI() {
+        require(msg.sender == XAPI, "!xapi");
+        _;
+    }
+
+    modifier onlyApproved() {
+        require(isApproved(msg.sender), "!approve");
+        _;
+    }
+
+    constructor(address dao, address ormp, address xapi, address exagg) {
+        PROTOCOL = ormp;
+        owner = dao;
+        XAPI = xapi;
+        EXAGGREGATOR = exagg;
+    }
+
+    receive() external payable {}
+
+    function version() public pure returns (string memory) {
+        return "1.0.0";
+    }
+
+    function _buildRequest(uint256 chainId, address channel, uint256 msgIndex)
+        internal
+        view
+        returns (XAPIBuilder.Request memory)
+    {
+        XAPIBuilder.Request memory requestData;
+        requestData._initialize(EXAGGREGATOR, this.xapiCallback.selector);
+        requestData._addParamUint("_dataSources", chainId);
+        requestData._startNestedParam("*");
+        {
+            requestData._startNestedParam("variables");
+            {
+                requestData._addParamUint("chainId", chainId);
+                requestData._addParam("channel", toHexString(channel));
+                requestData._addParamUint("msgIndex", msgIndex);
+            }
+            requestData._endNestedParam();
+        }
+        requestData._endNestedParam();
+        return requestData;
+    }
+
+    /// @dev Only could be called by approved address.
+    /// @param chainId The request source chain id.
+    /// @param channel The request message channel.
+    /// @param msgIndex The request message index.
+    function makeRequestForMessageHash(uint256 chainId, address channel, uint256 msgIndex)
+        external
+        payable
+        onlyApproved
+    {
+        XAPIBuilder.Request memory requestData = _buildRequest(chainId, channel, msgIndex);
+        uint256 fee_ = IXAPI(XAPI).fee(EXAGGREGATOR);
+        require(msg.value == fee_, "!fee");
+        requestId = IXAPI(XAPI).makeRequest{value: fee_}(requestData);
+        emit XAPIRequestMade(requestId, requestData);
+    }
+
+    function xapiCallback(uint256 requestId_, ResponseData memory response) external onlyXAPI {
+        require(requestId_ == requestId, "!requestId");
+        if (response.errorCode != 0) {
+            (uint256 chainId, address channel, uint256 msgIndex, bytes32 msgHash) =
+                abi.decode(response.result, (uint256, address, uint256, bytes32));
+            IORMP(PROTOCOL).importHash(chainId, channel, msgIndex, msgHash);
+            emit XAPIConsumeResult(requestId, response.result, response.errorCode);
+        } else {
+            emit XAPIConsumeError(requestId, response.errorCode);
+        }
+    }
+
+    function hashOf(uint256 chainId, address channel, uint256 msgIndex) public view override returns (bytes32) {
+        return IORMP(PROTOCOL).hashLookup(address(this), keccak256(abi.encode(chainId, channel, msgIndex)));
+    }
+
+    function changeOwner(address newOwner) external onlyOwner {
+        address oldOwner = owner;
+        owner = newOwner;
+        emit OwnershipTransferred(oldOwner, newOwner);
+    }
+
+    function setApproved(address operator, bool approve) external onlyOwner {
+        approvedOf[operator] = approve;
+        emit SetApproved(operator, approve);
+    }
+
+    function isApproved(address operator) public view returns (bool) {
+        return approvedOf[operator];
+    }
+
+    function withdraw(address to, uint256 amount) external onlyApproved {
+        (bool success,) = to.call{value: amount}("");
+        require(success, "!withdraw");
+        emit Withdrawal(to, amount);
+    }
+
+    function setFee(uint256 chainId, uint256 fee_) external onlyApproved {
+        feeOf[chainId] = fee_;
+        emit SetFee(chainId, fee_);
+    }
+
+    function fee(uint256 toChainId, address /*ua*/ ) public view returns (uint256) {
+        uint256 f = feeOf[toChainId];
+        require(f != 0, "!fee");
+        return f;
+    }
+
+    // Inspired from https://github.com/OpenZeppelin/openzeppelin-contracts/blob/v4.9.6/contracts/utils/Strings.sol
+    bytes16 private constant _SYMBOLS = "0123456789abcdef";
+    uint8 private constant _ADDRESS_LENGTH = 20;
+
+    function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
+        bytes memory buffer = new bytes(2 * length + 2);
+        buffer[0] = "0";
+        buffer[1] = "x";
+        for (uint256 i = 2 * length + 1; i > 1; --i) {
+            buffer[i] = _SYMBOLS[value & 0xf];
+            value >>= 4;
+        }
+        require(value == 0, "Strings: hex length insufficient");
+        return string(buffer);
+    }
+
+    function toHexString(address addr) internal pure returns (string memory) {
+        return toHexString(uint256(uint160(addr)), _ADDRESS_LENGTH);
+    }
+}