diff --git a/src/user/Application.sol b/src/user/Application.sol
index d4dc137..91c45f7 100644
--- a/src/user/Application.sol
+++ b/src/user/Application.sol
@@ -15,9 +15,8 @@
 // You should have received a copy of the GNU General Public License
 // along with Darwinia. If not, see <https://www.gnu.org/licenses/>.
 
-pragma solidity 0.8.17;
+pragma solidity ^0.8.17;
 
-import "../Common.sol";
 import "../interfaces/IORMP.sol";
 
 // https://eips.ethereum.org/EIPS/eip-5164
diff --git a/src/user/UpgradeableApplication.sol b/src/user/UpgradeableApplication.sol
new file mode 100644
index 0000000..e685caf
--- /dev/null
+++ b/src/user/UpgradeableApplication.sol
@@ -0,0 +1,78 @@
+// This file is part of Darwinia.
+// Copyright (C) 2018-2023 Darwinia Network
+// SPDX-License-Identifier: GPL-3.0
+//
+// Darwinia is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Darwinia is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Darwinia. If not, see <https://www.gnu.org/licenses/>.
+
+pragma solidity ^0.8.17;
+
+import "../interfaces/IORMP.sol";
+
+// https://eips.ethereum.org/EIPS/eip-5164
+abstract contract UpgradeableApplication {
+    address public sender;
+    address public recver;
+
+    event SetSender(address ormp);
+    event SetRecver(address ormp);
+
+    constructor(address ormp) {
+        sender = ormp;
+        recver = ormp;
+    }
+
+    function _setSender(address ormp) internal virtual {
+        sender = ormp;
+        emit SetSender(ormp);
+    }
+
+    function _setRecver(address ormp) internal virtual {
+        recver = ormp;
+        emit SetRecver(ormp);
+    }
+
+    function _setSenderConfig(address oracle, address relayer) internal virtual {
+        IORMP(sender).setAppConfig(oracle, relayer);
+    }
+
+    function _setRecverConfig(address oracle, address relayer) internal virtual {
+        IORMP(recver).setAppConfig(oracle, relayer);
+    }
+
+    modifier onlyORMP() {
+        require(recver == msg.sender, "!ormp");
+        _;
+    }
+
+    function _messageId() internal pure returns (bytes32 _msgDataMessageId) {
+        require(msg.data.length >= 84, "!messageId");
+        assembly {
+            _msgDataMessageId := calldataload(sub(calldatasize(), 84))
+        }
+    }
+
+    function _fromChainId() internal pure returns (uint256 _msgDataFromChainId) {
+        require(msg.data.length >= 52, "!fromChainId");
+        assembly {
+            _msgDataFromChainId := calldataload(sub(calldatasize(), 52))
+        }
+    }
+
+    function _xmsgSender() internal pure returns (address payable _from) {
+        require(msg.data.length >= 20, "!xmsgSender");
+        assembly {
+            _from := shr(96, calldataload(sub(calldatasize(), 20)))
+        }
+    }
+}
diff --git a/test/ORMP.t.sol b/test/ORMP.t.sol
index 981bf00..4074a78 100644
--- a/test/ORMP.t.sol
+++ b/test/ORMP.t.sol
@@ -56,14 +56,14 @@ contract ORMPTest is Test, Verifier {
 
     function test_Refunds() public {
         uint256 f = ormp.fee(2, self, 0, "", "");
-        ormp.send{value: f+5}(2, self, 0, "", address(5), "");
+        ormp.send{value: f + 5}(2, self, 0, "", address(5), "");
         assertEq(address(5).balance, 5);
     }
 
     function testFail_sendSameMsg() public {
         uint256 f1 = ormp.fee(2, self, 0, "", "");
         bytes32 msgHash1 = ormp.send{value: f1}(2, self, 0, "", self, "");
-        
+
         uint256 f2 = ormp.fee(2, self, 0, "", "");
         bytes32 msgHash2 = ormp.send{value: f2}(2, self, 0, "", self, "");
         vm.chainId(2);
@@ -94,12 +94,14 @@ contract ORMPTest is Test, Verifier {
         uint256 f = ormp.fee(2, self, 0, "", "");
         ormp.send{value: f}(2, self, 0, "", self, "");
         proof = Proof({blockNumber: block.number, messageIndex: ormp.messageCount() - 1, messageProof: ormp.prove()});
-        
+
         vm.chainId(2);
 
         bool returnValue = ormp.recv(message, abi.encode(proof));
-        assertEq(returnValue, false);                /// msg delivery failed
-        assertEq(ormp.dones(hash(message)), true);   /// but marked dispatched
+        /// msg delivery failed
+        assertEq(returnValue, false);
+        /// but marked dispatched
+        assertEq(ormp.dones(hash(message)), true);
     }
 
     function fee(uint256, address) external pure returns (uint256) {