diff --git a/contracts/flusher/logic.sol b/contracts/flusher/logic.sol
index e69de29..08e0698 100644
--- a/contracts/flusher/logic.sol
+++ b/contracts/flusher/logic.sol
@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.6.8;
+pragma experimental ABIEncoderV2;
+
+interface DeployerInterface {
+  function signer(address) external view returns (bool); 
+  function master() external view returns (address); 
+  function isConnector(address[] calldata) external view returns (bool);
+  function implementationLogic(address) external view returns (bool);
+}
+
+contract Setup {
+
+    function deployer() public pure returns (DeployerInterface) {
+        return DeployerInterface(address(0)); // TODO - change.
+    }
+
+    string constant public name = "Flusher-v1";
+
+    function spell(address _target, bytes memory _data) internal {
+        require(_target != address(0), "target-invalid");
+        assembly {
+        let succeeded := delegatecall(gas(), _target, add(_data, 0x20), mload(_data), 0, 0)
+        switch iszero(succeeded)
+            case 1 {
+                let size := returndatasize()
+                returndatacopy(0x00, 0x00, size)
+                revert(0x00, size)
+            }
+        }
+    }
+
+}
+
+contract UpgradeableProxy is Setup {
+    event Upgraded(address indexed implementation);
+
+    /**
+     * @dev Storage slot with the address of the current implementation.
+     * This is the keccak-256 hash of "eip1967.proxy.implementation" subtracted by 1.
+     */
+    bytes32 private constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
+
+    function changeImplementation(address newImplementation) public {
+        require(deployer().master() == msg.sender, "not-master");
+        require(deployer().implementationLogic(newImplementation), "not-whitelisted-logic");
+        // require(Address.isContract(newImplementation), "UpgradeableProxy: new implementation is not a contract");
+
+        bytes32 slot = _IMPLEMENTATION_SLOT;
+
+        // solhint-disable-next-line no-inline-assembly
+        assembly {
+            sstore(slot, newImplementation)
+        }
+        emit Upgraded(newImplementation);
+    }
+}
+
+
+contract Flusher is UpgradeableProxy {
+  event LogCast(address indexed sender, uint value);
+
+  function cast(address[] calldata _targets, bytes[] calldata _datas) external payable {
+    require(deployer().signer(msg.sender), "not-signer");
+    require(_targets.length == _datas.length , "invalid-array-length");
+    require(deployer().isConnector(_targets), "not-connector");
+    for (uint i = 0; i < _targets.length; i++) {
+        spell(_targets[i], _datas[i]);
+    }
+    emit LogCast(msg.sender, msg.value);
+  }
+
+  receive() external payable {}
+}
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