diff --git a/contracts/DODOVendorMachine/DVMFactory.sol b/contracts/DODOVendorMachine/DVMFactory.sol
deleted file mode 100644
index 4d5623a..0000000
--- a/contracts/DODOVendorMachine/DVMFactory.sol
+++ /dev/null
@@ -1,70 +0,0 @@
-/*
-
-    Copyright 2020 DODO ZOO.
-    SPDX-License-Identifier: Apache-2.0
-
-*/
-
-pragma solidity 0.6.9;
-pragma experimental ABIEncoderV2;
-
-import {Ownable} from "../lib/Ownable.sol";
-import {ICloneFactory} from "../lib/CloneFactory.sol";
-import {DVMVault} from "./impl/DVMVault.sol";
-import {DVMController} from "./impl/DVMController.sol";
-
-contract DVMFactory is Ownable {
-    address public _CLONE_FACTORY_;
-    address public _VAULT_TEMPLATE_;
-    address public _CONTROLLER_TEMPLATE_;
-
-    // base -> quote -> DVM address list
-    mapping(address => mapping(address => address[])) _REGISTRY_;
-
-    constructor(
-        address cloneFactory,
-        address vaultTemplate,
-        address controllerTemplate
-    ) public {
-        _CLONE_FACTORY_ = cloneFactory;
-        _VAULT_TEMPLATE_ = vaultTemplate;
-        _CONTROLLER_TEMPLATE_ = controllerTemplate;
-    }
-
-    function createDODOVendorMachine(
-        address maintainer,
-        address baseToken,
-        address quoteToken,
-        address lpFeeRateModel,
-        address mtFeeRateModel,
-        uint256 i,
-        uint256 k,
-        uint256 gasPriceLimit
-    ) external returns (address newVendorMachine) {
-        newVendorMachine = ICloneFactory(_CLONE_FACTORY_).clone(_CONTROLLER_TEMPLATE_);
-        address vault = ICloneFactory(_CLONE_FACTORY_).clone(_VAULT_TEMPLATE_);
-        DVMVault(vault).init(newVendorMachine, baseToken, quoteToken); // vault owner is controller
-
-        DVMController(newVendorMachine).init(
-            msg.sender,
-            maintainer,
-            vault,
-            lpFeeRateModel,
-            mtFeeRateModel,
-            i,
-            k,
-            gasPriceLimit
-        );
-
-        _REGISTRY_[baseToken][quoteToken].push(newVendorMachine);
-        return newVendorMachine;
-    }
-
-    function getVendorMachine(address baseToken, address quoteToken)
-        external
-        view
-        returns (address[] memory machines)
-    {
-        return _REGISTRY_[baseToken][quoteToken];
-    }
-}
diff --git a/contracts/DODOVendorMachine/impl/DVMController.sol b/contracts/DODOVendorMachine/impl/DVM.sol
similarity index 61%
rename from contracts/DODOVendorMachine/impl/DVMController.sol
rename to contracts/DODOVendorMachine/impl/DVM.sol
index 5abb225..8310d88 100644
--- a/contracts/DODOVendorMachine/impl/DVMController.sol
+++ b/contracts/DODOVendorMachine/impl/DVM.sol
@@ -8,32 +8,40 @@
 pragma solidity 0.6.9;
 pragma experimental ABIEncoderV2;
 
+import {IFeeRateModel} from "../../intf/IFeeRateModel.sol";
+import {IPermissionManager} from "../../lib/PermissionManager.sol";
 import {DVMTrader} from "./DVMTrader.sol";
 import {DVMFunding} from "./DVMFunding.sol";
-import {DVMAdmin} from "./DVMAdmin.sol";
 import {DVMVault} from "./DVMVault.sol";
-import {IFeeRateModel} from "../../intf/IFeeRateModel.sol";
 
-contract DVMController is DVMTrader, DVMFunding, DVMAdmin {
+contract DVM is DVMTrader, DVMFunding {
     function init(
         address owner,
         address maintainer,
         address vault,
         address lpFeeRateModel,
         address mtFeeRateModel,
+        address tradePermissionManager,
+        address fundingPermissionManager,
         uint256 i,
-        uint256 k,
-        uint256 gasPriceLimit
+        uint256 k
     ) external {
         initOwner(owner);
-        _MAINTAINER_ = maintainer;
         _VAULT_ = DVMVault(vault);
         _BASE_TOKEN_ = _VAULT_._BASE_TOKEN_();
         _QUOTE_TOKEN_ = _VAULT_._QUOTE_TOKEN_();
         _LP_FEE_RATE_MODEL_ = IFeeRateModel(lpFeeRateModel);
         _MT_FEE_RATE_MODEL_ = IFeeRateModel(mtFeeRateModel);
+        _TRADE_PERMISSION_ = IPermissionManager(tradePermissionManager);
+        _FUNDING_PERMISSION_ = IPermissionManager(fundingPermissionManager);
+        _MAINTAINER_ = maintainer;
         _I_ = i;
         _K_ = k;
-        _GAS_PRICE_LIMIT_ = gasPriceLimit;
+        _GAS_PRICE_LIMIT_ = uint256(-1);
+    }
+
+    // ============ Version Control ============
+    function version() external pure returns (uint256) {
+        return 100; // 1.0.0
     }
 }
diff --git a/contracts/DODOVendorMachine/impl/DVMAdmin.sol b/contracts/DODOVendorMachine/impl/DVMAdmin.sol
deleted file mode 100644
index 3738c41..0000000
--- a/contracts/DODOVendorMachine/impl/DVMAdmin.sol
+++ /dev/null
@@ -1,19 +0,0 @@
-/*
-
-    Copyright 2020 DODO ZOO.
-    SPDX-License-Identifier: Apache-2.0
-
-*/
-
-pragma solidity 0.6.9;
-pragma experimental ABIEncoderV2;
-
-import {DVMStorage} from "./DVMStorage.sol";
-
-contract DVMAdmin is DVMStorage{
-
-  function setI(uint256 newI) external onlyOwner{}
-
-  function setK(uint256 newK) external onlyOwner{}
-
-}
\ No newline at end of file
diff --git a/contracts/DODOVendorMachine/impl/DVMStorage.sol b/contracts/DODOVendorMachine/impl/DVMStorage.sol
index 9061dce..0d5f314 100644
--- a/contracts/DODOVendorMachine/impl/DVMStorage.sol
+++ b/contracts/DODOVendorMachine/impl/DVMStorage.sol
@@ -13,7 +13,7 @@ import {ReentrancyGuard} from "../../lib/ReentrancyGuard.sol";
 import {SafeMath} from "../../lib/SafeMath.sol";
 import {DODOMath} from "../../lib/DODOMath.sol";
 import {DecimalMath} from "../../lib/DecimalMath.sol";
-import {PermissionManager} from "../../lib/PermissionManager.sol";
+import {IPermissionManager} from "../../lib/PermissionManager.sol";
 import {IFeeRateModel} from "../../intf/IFeeRateModel.sol";
 import {DVMVault} from "./DVMVault.sol";
 
@@ -30,8 +30,8 @@ contract DVMStorage is InitializableOwnable, ReentrancyGuard {
     bool public _BUYING_ALLOWED_;
     bool public _SELLING_ALLOWED_;
 
-    PermissionManager public _TRADE_PERMISSION_;
-    PermissionManager public _FUNDING_PERMISSION_;
+    IPermissionManager public _TRADE_PERMISSION_;
+    IPermissionManager public _FUNDING_PERMISSION_;
 
     // ============ Core Address ============
 
@@ -48,7 +48,6 @@ contract DVMStorage is InitializableOwnable, ReentrancyGuard {
     uint256 public _I_;
 
     DVMVault public _VAULT_;
-    DVMVault public _PROTECTION_VAULT_;
 
     // ============ Modifiers ============
 
@@ -58,13 +57,31 @@ contract DVMStorage is InitializableOwnable, ReentrancyGuard {
     }
 
     // ============ Helper Functions ============
-    function getBase0() public view returns (uint256) {
-        uint256 fairAmount = DecimalMath.divFloor(_VAULT_._QUOTE_RESERVE_(), _I_);
-        return DODOMath._SolveQuadraticFunctionForTarget(_VAULT_._BASE_RESERVE_(), _K_, fairAmount);
+
+    function getBase0(uint256 baseAmount, uint256 quoteAmount) public view returns (uint256) {
+        uint256 fairAmount = DecimalMath.divFloor(quoteAmount, _I_);
+        return DODOMath._SolveQuadraticFunctionForTarget(baseAmount, _K_, fairAmount);
     }
 
-    // ============ Version Control ============
-    function version() external pure returns (uint256) {
-        return 101; // 1.0.1
+    // ============ Setting Functions ============
+
+    function setLpFeeRateModel(address newLpFeeRateModel) external onlyOwner {
+        _LP_FEE_RATE_MODEL_ = IFeeRateModel(newLpFeeRateModel);
+    }
+
+    function setMtFeeRateModel(address newMtFeeRateModel) external onlyOwner {
+        _MT_FEE_RATE_MODEL_ = IFeeRateModel(newMtFeeRateModel);
+    }
+
+    function setTradePermissionManager(address newTradePermissionManager) external onlyOwner {
+        _TRADE_PERMISSION_ = IPermissionManager(newTradePermissionManager);
+    }
+
+    function setFundingPermissionManager(address newFundingPermissionManager) external onlyOwner {
+        _FUNDING_PERMISSION_ = IPermissionManager(newFundingPermissionManager);
+    }
+
+    function setMaintainer(address newMaintainer) external onlyOwner {
+        _MAINTAINER_ = newMaintainer;
     }
 }
diff --git a/contracts/DODOVendorMachine/impl/DVMTrader.sol b/contracts/DODOVendorMachine/impl/DVMTrader.sol
index f374d5e..c212df4 100644
--- a/contracts/DODOVendorMachine/impl/DVMTrader.sol
+++ b/contracts/DODOVendorMachine/impl/DVMTrader.sol
@@ -12,6 +12,7 @@ import {DVMStorage} from "./DVMStorage.sol";
 import {SafeMath} from "../../lib/SafeMath.sol";
 import {DecimalMath} from "../../lib/DecimalMath.sol";
 import {DODOMath} from "../../lib/DODOMath.sol";
+import {IExternalCall} from "../intf/IExternalCall.sol";
 
 contract DVMTrader is DVMStorage {
     using SafeMath for uint256;
@@ -19,7 +20,7 @@ contract DVMTrader is DVMStorage {
     function sellBase(address to) external returns (uint256 receiveQuoteAmount) {
         uint256 baseInput = _VAULT_.getBaseInput();
         uint256 mtFee;
-        (receiveQuoteAmount, mtFee) = querySellBase(baseInput);
+        (receiveQuoteAmount, mtFee) = querySellBase(to, baseInput);
         _VAULT_.transferQuoteOut(to, receiveQuoteAmount);
         if (mtFee > 0) {
             _VAULT_.transferQuoteOut(_MAINTAINER_, mtFee);
@@ -31,7 +32,7 @@ contract DVMTrader is DVMStorage {
     function sellQuote(address to) external returns (uint256 receiveBaseAmount) {
         uint256 quoteInput = _VAULT_.getQuoteInput();
         uint256 mtFee;
-        (receiveBaseAmount, mtFee) = querySellQuote(quoteInput);
+        (receiveBaseAmount, mtFee) = querySellQuote(to, quoteInput);
         _VAULT_.transferBaseOut(to, receiveBaseAmount);
         if (mtFee > 0) {
             _VAULT_.transferBaseOut(_MAINTAINER_, mtFee);
@@ -40,50 +41,82 @@ contract DVMTrader is DVMStorage {
         return receiveBaseAmount;
     }
 
-    function querySellBase(uint256 payBaseAmount)
+    function flashLoan(
+        uint256 baseAmount,
+        uint256 quoteAmount,
+        address assetTo,
+        address call,
+        bytes calldata data
+    ) external {
+        (uint256 baseReserve, uint256 quoteReserve) = _VAULT_.getVaultReserve();
+        uint256 B0 = getBase0(baseReserve, quoteReserve);
+
+        uint256 mtFeeRate = _MT_FEE_RATE_MODEL_.getFeeRate(assetTo, quoteAmount);
+        uint256 baseMtFee = DecimalMath.mulCeil(baseAmount, mtFeeRate);
+        uint256 quoteMtFee = DecimalMath.mulCeil(quoteAmount, mtFeeRate);
+
+        _VAULT_.transferBaseOut(_MAINTAINER_, baseMtFee);
+        _VAULT_.transferQuoteOut(_MAINTAINER_, quoteMtFee);
+        _VAULT_.transferBaseOut(assetTo, baseAmount);
+        _VAULT_.transferQuoteOut(assetTo, quoteAmount);
+
+        IExternalCall(call).DVMCall(data);
+
+        (uint256 baseBalance, uint256 quoteBalance) = _VAULT_.getVaultBalance();
+        uint256 newB0 = getBase0(baseBalance, quoteBalance);
+        require(newB0 >= B0, "FLASH_LOAN_FAILED");
+        _VAULT_.sync();
+    }
+
+    function querySellBase(address trader, uint256 payBaseAmount)
         public
         view
         returns (uint256 receiveQuoteAmount, uint256 mtFee)
     {
-        uint256 B0 = getBase0();
-        uint256 B2 = _VAULT_._BASE_RESERVE_();
-        uint256 B1 = B2.add(payBaseAmount);
+        (uint256 baseReserve, uint256 quoteReserve) = _VAULT_.getVaultReserve();
+        uint256 B0 = getBase0(baseReserve, quoteReserve);
+
+        uint256 B1 = baseReserve.add(payBaseAmount);
         require(B0 >= B1, "DODO_BASE_BALANCE_NOT_ENOUGH");
-        uint256 Q = DODOMath._GeneralIntegrate(B0, B1, B2, _I_, _K_);
-        uint256 lpFeeRate = _LP_FEE_RATE_MODEL_.getFeeRate(Q);
-        uint256 mtFeeRate = _MT_FEE_RATE_MODEL_.getFeeRate(Q);
+        uint256 Q = DODOMath._GeneralIntegrate(B0, B1, baseReserve, _I_, _K_);
+
+        uint256 lpFeeRate = _LP_FEE_RATE_MODEL_.getFeeRate(trader, Q);
+        uint256 mtFeeRate = _MT_FEE_RATE_MODEL_.getFeeRate(trader, Q);
         mtFee = DecimalMath.mulCeil(Q, mtFeeRate);
         receiveQuoteAmount = Q.sub(mtFee).sub(DecimalMath.mulCeil(Q, lpFeeRate));
+
         return (receiveQuoteAmount, mtFee);
     }
 
-    function querySellQuote(uint256 payQuoteAmount)
+    function querySellQuote(address trader, uint256 payQuoteAmount)
         public
         view
         returns (uint256 receiveBaseAmount, uint256 mtFee)
     {
-        uint256 B0 = getBase0();
-        uint256 B1 = _VAULT_._BASE_RESERVE_();
+        (uint256 baseReserve, uint256 quoteReserve) = _VAULT_.getVaultReserve();
+        uint256 B0 = getBase0(baseReserve, quoteReserve);
+
         uint256 fairAmount = DecimalMath.divFloor(payQuoteAmount, _I_);
         uint256 newBaseReserve = DODOMath._SolveQuadraticFunctionForTrade(
             B0,
-            B1,
+            baseReserve,
             fairAmount,
             false,
             _K_
         );
-        uint256 deltaBase = B1.sub(newBaseReserve);
-        uint256 lpFeeRate = _LP_FEE_RATE_MODEL_.getFeeRate(payQuoteAmount);
-        uint256 mtFeeRate = _MT_FEE_RATE_MODEL_.getFeeRate(payQuoteAmount);
+        uint256 deltaBase = baseReserve.sub(newBaseReserve);
+        uint256 lpFeeRate = _LP_FEE_RATE_MODEL_.getFeeRate(trader, payQuoteAmount);
+        uint256 mtFeeRate = _MT_FEE_RATE_MODEL_.getFeeRate(trader, payQuoteAmount);
         mtFee = DecimalMath.mulCeil(deltaBase, mtFeeRate);
         receiveBaseAmount = deltaBase.sub(mtFee).sub(DecimalMath.mulCeil(deltaBase, lpFeeRate));
         return (receiveBaseAmount, mtFee);
     }
 
     function getMidPrice() public view returns (uint256 midPrice) {
-        uint256 B0 = getBase0();
-        uint256 B1 = _VAULT_._BASE_RESERVE_();
-        uint256 offsetRatio = DecimalMath.ONE.mul(B0).div(B1).mul(B0).div(B1);
+        (uint256 baseReserve, uint256 quoteReserve) = _VAULT_.getVaultReserve();
+        uint256 B0 = getBase0(baseReserve, quoteReserve);
+
+        uint256 offsetRatio = DecimalMath.ONE.mul(B0).div(baseReserve).mul(B0).div(baseReserve);
         uint256 offset = DecimalMath.ONE.sub(_K_).add(DecimalMath.mulFloor(offsetRatio, _K_));
         return DecimalMath.mulFloor(_I_, offset);
     }
diff --git a/contracts/DODOVendorMachine/impl/DVMVault.sol b/contracts/DODOVendorMachine/impl/DVMVault.sol
index 5e0e5d9..f68315d 100644
--- a/contracts/DODOVendorMachine/impl/DVMVault.sol
+++ b/contracts/DODOVendorMachine/impl/DVMVault.sol
@@ -109,14 +109,6 @@ contract DVMVault is InitializableOwnable {
         }
     }
 
-    function transferOut(
-        address token,
-        address to,
-        uint256 amount
-    ) public onlyOwner {
-        IERC20(token).safeTransfer(to, amount);
-    }
-
     function transferBaseOut(address to, uint256 amount) public onlyOwner {
         IERC20(_BASE_TOKEN_).safeTransfer(to, amount);
     }
@@ -208,4 +200,6 @@ contract DVMVault is InitializableOwnable {
         emit Burn(user, value);
         emit Transfer(user, address(0), value);
     }
+
+    // function approveAndCall()
 }
diff --git a/contracts/DODOVendorMachine/intf/IDVM.sol b/contracts/DODOVendorMachine/intf/IDVM.sol
new file mode 100644
index 0000000..8569973
--- /dev/null
+++ b/contracts/DODOVendorMachine/intf/IDVM.sol
@@ -0,0 +1,23 @@
+/*
+
+    Copyright 2020 DODO ZOO.
+    SPDX-License-Identifier: Apache-2.0
+
+*/
+
+pragma solidity 0.6.9;
+pragma experimental ABIEncoderV2;
+
+interface IDVM {
+    function init(
+        address owner,
+        address maintainer,
+        address vault,
+        address lpFeeRateModel,
+        address mtFeeRateModel,
+        address tradePermissionManager,
+        address fundingPermissionManager,
+        uint256 i,
+        uint256 k
+    ) external;
+}
diff --git a/contracts/DODOVendorMachine/intf/IDVMVault.sol b/contracts/DODOVendorMachine/intf/IDVMVault.sol
new file mode 100644
index 0000000..eba49e2
--- /dev/null
+++ b/contracts/DODOVendorMachine/intf/IDVMVault.sol
@@ -0,0 +1,17 @@
+/*
+
+    Copyright 2020 DODO ZOO.
+    SPDX-License-Identifier: Apache-2.0
+
+*/
+
+pragma solidity 0.6.9;
+pragma experimental ABIEncoderV2;
+
+interface IDVMVault {
+    function init(
+        address owner,
+        address _baseToken,
+        address _quoteToken
+    ) external;
+}
diff --git a/contracts/DODOVendorMachine/intf/IExternalCall.sol b/contracts/DODOVendorMachine/intf/IExternalCall.sol
new file mode 100644
index 0000000..fbd517e
--- /dev/null
+++ b/contracts/DODOVendorMachine/intf/IExternalCall.sol
@@ -0,0 +1,13 @@
+/*
+
+    Copyright 2020 DODO ZOO.
+    SPDX-License-Identifier: Apache-2.0
+
+*/
+
+pragma solidity 0.6.9;
+pragma experimental ABIEncoderV2;
+
+interface IExternalCall {
+    function DVMCall(bytes calldata data) external;
+}
diff --git a/contracts/Factory/DVMFactory.sol b/contracts/Factory/DVMFactory.sol
new file mode 100644
index 0000000..f67369f
--- /dev/null
+++ b/contracts/Factory/DVMFactory.sol
@@ -0,0 +1,93 @@
+/*
+
+    Copyright 2020 DODO ZOO.
+    SPDX-License-Identifier: Apache-2.0
+
+*/
+
+pragma solidity 0.6.9;
+pragma experimental ABIEncoderV2;
+
+import {Ownable} from "../lib/Ownable.sol";
+import {ICloneFactory} from "../lib/CloneFactory.sol";
+import {IConstFeeRateModel} from "../lib/ConstFeeRateModel.sol";
+import {IDVM} from "../DODOVendorMachine/intf/IDVM.sol";
+import {IDVMVault} from "../DODOVendorMachine/intf/IDVMVault.sol";
+import {IPermissionManager} from "../lib/PermissionManager.sol";
+
+contract DVMFactory is Ownable {
+    address public _CLONE_FACTORY_;
+    address public _VAULT_TEMPLATE_;
+    address public _DVM_TEMPLATE_;
+    address public _FEE_RATE_MODEL_TEMPLATE_;
+    address public _PERMISSION_MANAGER_TEMPLATE_;
+
+    // base -> quote -> DVM address list
+    mapping(address => mapping(address => address[])) _REGISTRY_;
+
+    constructor(
+        address cloneFactory,
+        address vaultTemplate,
+        address dvmTemplate,
+        address feeRateModelTemplate,
+        address permissionManagerTemplate
+    ) public {
+        _CLONE_FACTORY_ = cloneFactory;
+        _VAULT_TEMPLATE_ = vaultTemplate;
+        _DVM_TEMPLATE_ = dvmTemplate;
+        _FEE_RATE_MODEL_TEMPLATE_ = feeRateModelTemplate;
+        _PERMISSION_MANAGER_TEMPLATE_ = permissionManagerTemplate;
+    }
+
+    function createStandardDODOVendorMachine(
+        address baseToken,
+        address quoteToken,
+        uint256 lpFeeRate,
+        uint256 mtFeeRate,
+        uint256 i,
+        uint256 k
+    ) external returns (address newVendorMachine) {
+        newVendorMachine = ICloneFactory(_CLONE_FACTORY_).clone(_DVM_TEMPLATE_);
+
+        address vault = ICloneFactory(_CLONE_FACTORY_).clone(_VAULT_TEMPLATE_);
+
+        IDVMVault(vault).init(newVendorMachine, baseToken, quoteToken); // vault owner is controller
+        IDVM(newVendorMachine).init(
+            msg.sender,
+            msg.sender,
+            vault,
+            createConstFeeRateModel(msg.sender, lpFeeRate),
+            createConstFeeRateModel(msg.sender, mtFeeRate),
+            createPermissionManager(msg.sender),
+            createPermissionManager(msg.sender),
+            i,
+            k
+        );
+
+        _REGISTRY_[baseToken][quoteToken].push(newVendorMachine);
+        return newVendorMachine;
+    }
+
+    function createConstFeeRateModel(address owner, uint256 feeRate)
+        public
+        returns (address feeRateModel)
+    {
+        feeRateModel = ICloneFactory(_CLONE_FACTORY_).clone(_FEE_RATE_MODEL_TEMPLATE_);
+        IConstFeeRateModel(feeRateModel).init(owner, feeRate);
+        return feeRateModel;
+    }
+
+    function createPermissionManager(address owner) public returns (address permissionManager) {
+        permissionManager = ICloneFactory(_CLONE_FACTORY_).clone(_PERMISSION_MANAGER_TEMPLATE_);
+        IPermissionManager(permissionManager).initOwner(owner);
+        return permissionManager;
+    }
+
+    function getVendorMachine(address baseToken, address quoteToken)
+        external
+        view
+        returns (address[] memory machines)
+    {
+        return _REGISTRY_[baseToken][quoteToken];
+    }
+}
diff --git a/contracts/SmartRoute/SmartRoute.sol b/contracts/SmartRoute/SmartRoute.sol
index f1a7712..d7949bf 100644
--- a/contracts/SmartRoute/SmartRoute.sol
+++ b/contracts/SmartRoute/SmartRoute.sol
@@ -8,7 +8,7 @@
 pragma solidity 0.6.9;
 
 import {Ownable} from "../lib/Ownable.sol";
-import {DVMController} from "../DODOVendorMachine/impl/DVMController.sol";
+import {DVM} from "../DODOVendorMachine/impl/DVM.sol";
 import {DVMVault} from "../DODOVendorMachine/impl/DVMVault.sol";
 import {IERC20} from "../intf/IERC20.sol";
 import {SafeERC20} from "../lib/SafeERC20.sol";
@@ -20,49 +20,47 @@ contract SmartRoute is Ownable {
     using SafeERC20 for IERC20;
 
     function sellBaseOnDVM(
-        address DVM,
+        address DVMAddress,
         address to,
         uint256 baseAmount,
         uint256 minReceive
     ) public returns (uint256 receiveAmount) {
-        IERC20(DVMController(DVM)._BASE_TOKEN_()).safeTransferFrom(
+        IERC20(DVM(DVMAddress)._BASE_TOKEN_()).safeTransferFrom(
             msg.sender,
-            address(DVMController(DVM)._VAULT_()),
+            address(DVM(DVMAddress)._VAULT_()),
             baseAmount
         );
-        receiveAmount = DVMController(DVM).sellBase(to);
+        receiveAmount = DVM(DVMAddress).sellBase(to);
         require(receiveAmount >= minReceive, "RECEIVE_NOT_ENOUGH");
         return receiveAmount;
     }
 
     function sellQuoteOnDVM(
-        address DVM,
+        address DVMAddress,
         address to,
         uint256 quoteAmount,
         uint256 minReceive
     ) public returns (uint256 receiveAmount) {
-        IERC20(DVMController(DVM)._QUOTE_TOKEN_()).safeTransferFrom(
+        IERC20(DVM(DVMAddress)._QUOTE_TOKEN_()).safeTransferFrom(
             msg.sender,
-            address(DVMController(DVM)._VAULT_()),
+            address(DVM(DVMAddress)._VAULT_()),
             quoteAmount
         );
-        receiveAmount = DVMController(DVM).sellQuote(to);
+        receiveAmount = DVM(DVMAddress).sellQuote(to);
         require(receiveAmount >= minReceive, "RECEIVE_NOT_ENOUGU");
         return receiveAmount;
     }
 
     function depositToDVM(
-        address DVM,
+        address DVMAddress,
         address to,
         uint256 baseAmount,
         uint256 quoteAmount
     ) public returns (uint256 shares) {
-        address vault = address(DVMController(DVM)._VAULT_());
+        address vault = address(DVM(DVMAddress)._VAULT_());
         uint256 adjustedBaseAmount;
         uint256 adjustedQuoteAmount;
-        (uint256 baseReserve, uint256 quoteReserve) = DVMController(DVM)
-            ._VAULT_()
-            .getVaultReserve();
+        (uint256 baseReserve, uint256 quoteReserve) = DVM(DVMAddress)._VAULT_().getVaultReserve();
 
         if (quoteReserve == 0 && baseReserve == 0) {
             adjustedBaseAmount = baseAmount;
@@ -86,17 +84,17 @@ contract SmartRoute is Ownable {
             }
         }
 
-        IERC20(DVMController(DVM)._BASE_TOKEN_()).safeTransferFrom(
+        IERC20(DVM(DVMAddress)._BASE_TOKEN_()).safeTransferFrom(
             msg.sender,
             vault,
             adjustedBaseAmount
         );
-        IERC20(DVMController(DVM)._QUOTE_TOKEN_()).safeTransferFrom(
+        IERC20(DVM(DVMAddress)._QUOTE_TOKEN_()).safeTransferFrom(
             msg.sender,
             vault,
             adjustedQuoteAmount
         );
 
-        return DVMController(DVM).buyShares(to);
+        return DVM(DVMAddress).buyShares(to);
     }
 }
diff --git a/contracts/helper/ConstFeeRateModel.sol b/contracts/helper/ConstFeeRateModel.sol
deleted file mode 100644
index a3afd17..0000000
--- a/contracts/helper/ConstFeeRateModel.sol
+++ /dev/null
@@ -1,23 +0,0 @@
-/*
-
-    Copyright 2020 DODO ZOO.
-    SPDX-License-Identifier: Apache-2.0
-
-*/
-
-pragma solidity 0.6.9;
-pragma experimental ABIEncoderV2;
-
-import {IFeeRateModel} from "../intf/IFeeRateModel.sol";
-
-contract ConstFeeRateModel is IFeeRateModel {
-    uint256 public _FEE_RATE_;
-
-    constructor(uint256 feeRate) public {
-        feeRate = _FEE_RATE_;
-    }
-
-    function getFeeRate(uint256) external override view returns (uint256) {
-        return _FEE_RATE_;
-    }
-}
diff --git a/contracts/helper/NaiveFeeRateModel.sol b/contracts/helper/NaiveFeeRateModel.sol
deleted file mode 100644
index 7b5727d..0000000
--- a/contracts/helper/NaiveFeeRateModel.sol
+++ /dev/null
@@ -1,28 +0,0 @@
-/*
-
-    Copyright 2020 DODO ZOO.
-    SPDX-License-Identifier: Apache-2.0
-
-*/
-
-pragma solidity 0.6.9;
-pragma experimental ABIEncoderV2;
-
-import {IFeeRateModel} from "../intf/IFeeRateModel.sol";
-import {Ownable} from "../lib/Ownable.sol";
-
-contract NaiveFeeRateModel is Ownable, IFeeRateModel {
-    uint256 public _FEE_RATE_;
-
-    constructor(uint256 feeRate) public {
-        _FEE_RATE_ = feeRate;
-    }
-
-    function setFeeRate(uint256 newFeeRate) external {
-        _FEE_RATE_ = newFeeRate;
-    }
-
-    function getFeeRate(uint256) external override view returns (uint256) {
-        return _FEE_RATE_;
-    }
-}
diff --git a/contracts/intf/IFeeRateModel.sol b/contracts/intf/IFeeRateModel.sol
index 81c3fdd..10e7a30 100644
--- a/contracts/intf/IFeeRateModel.sol
+++ b/contracts/intf/IFeeRateModel.sol
@@ -8,7 +8,6 @@
 pragma solidity 0.6.9;
 pragma experimental ABIEncoderV2;
 
-
 interface IFeeRateModel {
-    function getFeeRate(uint256 amount) external view returns (uint256);
+    function getFeeRate(address trader, uint256 amount) external view returns (uint256);
 }
diff --git a/contracts/lib/ConstFeeRateModel.sol b/contracts/lib/ConstFeeRateModel.sol
new file mode 100644
index 0000000..4cf695c
--- /dev/null
+++ b/contracts/lib/ConstFeeRateModel.sol
@@ -0,0 +1,38 @@
+/*
+
+    Copyright 2020 DODO ZOO.
+    SPDX-License-Identifier: Apache-2.0
+
+*/
+
+pragma solidity 0.6.9;
+pragma experimental ABIEncoderV2;
+
+import {IFeeRateModel} from "../intf/IFeeRateModel.sol";
+import {Ownable} from "../lib/Ownable.sol";
+import {InitializableOwnable} from "../lib/InitializableOwnable.sol";
+
+interface IConstFeeRateModel {
+    function init(address owner, uint256 feeRate) external;
+
+    function setFeeRate(uint256 newFeeRate) external;
+
+    function getFeeRate(address, uint256) external view returns (uint256);
+}
+
+contract ConstFeeRateModel is InitializableOwnable, IFeeRateModel {
+    uint256 public _FEE_RATE_;
+
+    function init(address owner, uint256 feeRate) external {
+        initOwner(owner);
+        _FEE_RATE_ = feeRate;
+    }
+
+    function setFeeRate(uint256 newFeeRate) external {
+        _FEE_RATE_ = newFeeRate;
+    }
+
+    function getFeeRate(address, uint256) external override view returns (uint256) {
+        return _FEE_RATE_;
+    }
+}
diff --git a/contracts/lib/OperatorSystem.sol b/contracts/lib/OperatorSystem.sol
new file mode 100644
index 0000000..c2be516
--- /dev/null
+++ b/contracts/lib/OperatorSystem.sol
@@ -0,0 +1,36 @@
+/*
+
+    Copyright 2020 DODO ZOO.
+    SPDX-License-Identifier: Apache-2.0
+
+*/
+
+pragma solidity 0.6.9;
+pragma experimental ABIEncoderV2;
+
+import {InitializableOwnable} from "./InitializableOwnable.sol";
+
+contract OperatorSystem is InitializableOwnable {
+    mapping(address => bool) internal _global_operator_;
+    mapping(address => mapping(address => bool)) internal _operator_; // user=>operator=>isValid
+
+    function isValidOperator(address user, address operator) external view returns (bool) {
+        return user == operator || _global_operator_[operator] || _operator_[user][operator];
+    }
+
+    function addGlobalOperator(address operator) external onlyOwner {
+        _global_operator_[operator] = true;
+    }
+
+    function removeGlobalOperator(address operator) external onlyOwner {
+        _global_operator_[operator] = false;
+    }
+
+    function addOperator(address operator) external {
+        _operator_[msg.sender][operator] = true;
+    }
+
+    function removeOperator(address operator) external {
+        _operator_[msg.sender][operator] = false;
+    }
+}
diff --git a/contracts/lib/PermissionManager.sol b/contracts/lib/PermissionManager.sol
index e813039..cc9d6d7 100644
--- a/contracts/lib/PermissionManager.sol
+++ b/contracts/lib/PermissionManager.sol
@@ -10,44 +10,47 @@ pragma experimental ABIEncoderV2;
 
 import {InitializableOwnable} from "./InitializableOwnable.sol";
 
+interface IPermissionManager {
+    function initOwner(address) external;
+
+    function isAllowed(address) external returns (bool);
+}
+
 contract PermissionManager is InitializableOwnable {
+    bool public _BLACKLIST_MODE_ON_;
 
-  bool public _BLACKLIST_MODE_ON_;
+    mapping(address => bool) internal _whitelist_;
+    mapping(address => bool) internal _blacklist_;
 
-  mapping(address => bool) internal _whitelist_;
-  mapping(address => bool) internal _blacklist_;
-
-  function isAllowed(address account) external view returns(bool){
-    if (_BLACKLIST_MODE_ON_) {
-      return !_blacklist_[account];
-    } else {
-      return _whitelist_[account];
+    function isAllowed(address account) external view returns (bool) {
+        if (_BLACKLIST_MODE_ON_) {
+            return !_blacklist_[account];
+        } else {
+            return _whitelist_[account];
+        }
     }
-  }
 
-  function openBlacklist() external onlyOwner {
-    _BLACKLIST_MODE_ON_ = true;
-  }
+    function openBlacklist() external onlyOwner {
+        _BLACKLIST_MODE_ON_ = true;
+    }
 
-  function openWhitelist() external onlyOwner {
-    _BLACKLIST_MODE_ON_ = true;
+    function openWhitelist() external onlyOwner {
+        _BLACKLIST_MODE_ON_ = true;
+    }
 
-  }
+    function addToWhitelist(address account) external onlyOwner {
+        _whitelist_[account] = true;
+    }
 
-  function addToWhitelist(address account) external onlyOwner{
-    _whitelist_[account] = true;
-  }
+    function removeFromWhitelist(address account) external onlyOwner {
+        _whitelist_[account] = false;
+    }
 
-  function removeFromWhitelist(address account) external onlyOwner{
-    _whitelist_[account] = false;
-  }
+    function addToBlacklist(address account) external onlyOwner {
+        _blacklist_[account] = true;
+    }
 
-  function addToBlacklist(address account) external onlyOwner{
-    _blacklist_[account] = true;
-  }
-
-  function removeFromBlacklist(address account) external onlyOwner{
-    _blacklist_[account] = false;
-  }
-
-}
\ No newline at end of file
+    function removeFromBlacklist(address account) external onlyOwner {
+        _blacklist_[account] = false;
+    }
+}