Merge branch 'v2-prototype' into abi-gen-ignore-unchanged

85 files changed, 1216 insertions, 706 deletions

diff --git a/packages/contracts/.solhint.json b/packages/contracts/.solhint.json
index 7e3b4dca2..076afe9f3 100644
--- a/packages/contracts/.solhint.json
+++ b/packages/contracts/.solhint.json
@@ -1,17 +1,20 @@
 {
     "extends": "default",
     "rules": {
-        "bracket-align": "warn",
-        "code-complexity": "warn",
-        "const-name-snakecase": "warn",
-        "expression-indent": "warn",
-        "function-max-lines": "warn",
-        "statement-indent": "warn",
-        "indent": ["warn", 4],
+        "avoid-low-level-calls": false,
+        "avoid-tx-origin": "warn",
+        "bracket-align": false,
+        "code-complexity": false,
+        "const-name-snakecase": "error",
+        "expression-indent": "error",
+        "function-max-lines": false,
+        "func-order": "error",
+        "indent": ["error", 4],
+        "max-line-length": ["warn", 160],
+        "no-inline-assembly": false,
         "quotes": ["error", "double"],
-        "max-line-length": ["warn", 120],
-        "separate-by-one-line-in-contract": "warn",
+        "separate-by-one-line-in-contract": "error",
         "space-after-comma": "error",
-        "func-order": "warn"
+        "statement-indent": "error"
     }
 }
diff --git a/packages/contracts/package.json b/packages/contracts/package.json
index a8bbdbe16..98b133e63 100644
--- a/packages/contracts/package.json
+++ b/packages/contracts/package.json
@@ -1,7 +1,7 @@
 {
     "private": true,
     "name": "contracts",
-    "version": "2.1.33",
+    "version": "2.1.34",
     "engines": {
         "node": ">=6.12"
     },
@@ -24,13 +24,13 @@
         "compile": "sol-compiler --contracts-dir src",
         "clean": "shx rm -rf lib generated_contract_wrappers",
         "generate_contract_wrappers": "abi-gen --abis  ${npm_package_config_abis} --template ../contract_templates/contract.handlebars --partials '../contract_templates/partials/**/*.handlebars' --output generated_contract_wrappers --backend ethers",
-        "lint": "tslint --project . --exclude **/src/generated_contract_wrappers/**/* --exclude **/lib/**/*",
+        "lint": "tslint --project . --exclude **/src/generated_contract_wrappers/**/* --exclude **/lib/**/* && yarn lint-contracts",
         "coverage:report:text": "istanbul report text",
         "coverage:report:html": "istanbul report html && open coverage/index.html",
         "profiler:report:html": "istanbul report html && open coverage/index.html",
         "coverage:report:lcov": "istanbul report lcov",
         "test:circleci": "yarn test",
-        "lint-contracts": "solhint src/2.0.0/**/*.sol"
+        "lint-contracts": "solhint src/2.0.0/**/**/**/**/*.sol"
     },
     "config": {
         "abis": "../migrations/artifacts/2.0.0/@(AssetProxyOwner|DummyERC20Token|DummyERC721Receiver|DummyERC721Token|ERC20Proxy|ERC721Proxy|Forwarder|Exchange|ExchangeWrapper|IAssetData|IAssetProxy|MixinAuthorizable|MultiSigWallet|MultiSigWalletWithTimeLock|TestAssetProxyOwner|TestAssetProxyDispatcher|TestLibBytes|TestLibs|TestSignatureValidator|TestValidator|TestWallet|TokenRegistry|Whitelist|WETH9|ZRXToken).json"
@@ -46,11 +46,11 @@
     },
     "homepage": "https://github.com/0xProject/0x-monorepo/packages/contracts/README.md",
     "devDependencies": {
-        "@0xproject/abi-gen": "^0.3.2",
-        "@0xproject/dev-utils": "^0.4.4",
-        "@0xproject/tslint-config": "^0.4.20",
-        "@0xproject/subproviders": "^0.10.1",
-        "@0xproject/sol-cov": "^0.1.1",
+        "@0xproject/abi-gen": "^0.3.3",
+        "@0xproject/dev-utils": "^0.4.5",
+        "@0xproject/tslint-config": "^0.4.21",
+        "@0xproject/subproviders": "^0.10.5",
+        "@0xproject/sol-cov": "^0.1.2",
         "@types/lodash": "4.14.104",
         "@types/bn.js": "^4.11.0",
         "@types/node": "^8.0.53",
@@ -72,13 +72,13 @@
         "yargs": "^10.0.3"
     },
     "dependencies": {
-        "@0xproject/base-contract": "^0.3.4",
+        "@0xproject/base-contract": "^0.3.5",
         "@0xproject/order-utils": "^1.0.0",
-        "@0xproject/sol-compiler": "^0.5.2",
+        "@0xproject/sol-compiler": "^0.5.3",
         "@0xproject/types": "^1.0.0",
-        "@0xproject/typescript-typings": "^0.4.1",
-        "@0xproject/utils": "^0.7.1",
-        "@0xproject/web3-wrapper": "^0.7.1",
+        "@0xproject/typescript-typings": "^0.4.2",
+        "@0xproject/utils": "^0.7.2",
+        "@0xproject/web3-wrapper": "^0.7.2",
         "ethereum-types": "^0.0.2",
         "bn.js": "^4.11.8",
         "ethereumjs-abi": "^0.6.4",
diff --git a/packages/contracts/src/2.0.0/forwarder/Forwarder.sol b/packages/contracts/src/2.0.0/forwarder/Forwarder.sol
index 71a4aff13..fc17a4c72 100644
--- a/packages/contracts/src/2.0.0/forwarder/Forwarder.sol
+++ b/packages/contracts/src/2.0.0/forwarder/Forwarder.sol
@@ -16,24 +16,25 @@
 
 */
 
-pragma solidity ^0.4.24;
+pragma solidity 0.4.24;
 pragma experimental ABIEncoderV2;
 
-import "./MixinWethFees.sol";
-import "./MixinMarketSellTokens.sol";
-import "./MixinMarketBuyTokens.sol";
+import "./MixinFees.sol";
+import "./MixinForwarderCore.sol";
 import "./MixinConstants.sol";
-import "../utils/Ownable/Ownable.sol";
+import "./MixinMarketBuyZrx.sol";
+import "./MixinExpectedResults.sol";
+import "./MixinTransfer.sol";
+
 
 contract Forwarder is
-    Ownable,
     MixinConstants,
-    MixinWethFees,
+    MixinExpectedResults,
+    MixinFees,
     MixinMarketBuyZrx,
-    MixinMarketBuyTokens,
-    MixinMarketSellTokens
+    MixinTransfer,
+    MixinForwarderCore
 {
-    uint256 MAX_UINT = 2**256 - 1;
 
     constructor (
         address _exchange,
@@ -44,7 +45,6 @@ contract Forwarder is
         bytes memory _wethAssetData
     )
         public
-        Ownable()
         MixinConstants(
             _exchange,
             _etherToken,
@@ -52,30 +52,6 @@ contract Forwarder is
             _zrxAssetData,
             _wethAssetData
         )
-    {
-        setERC20ProxyApproval(_erc20AssetProxyId);
-    }
-
-    /// @dev Default payabale function, this allows us to withdraw WETH
-    function ()
-        public
-        payable
-    {
-        require(
-            msg.sender == address(ETHER_TOKEN),
-            "DEFAULT_FUNCTION_WETH_CONTRACT_ONLY"
-        );
-    }
-
-    /// @dev Sets the allowances to the proxy for this contract
-    function setERC20ProxyApproval(bytes4 erc20AssetProxyId)
-        public
-        onlyOwner
-    {
-        address proxyAddress = EXCHANGE.getAssetProxy(erc20AssetProxyId);
-        if (proxyAddress != address(0)) {
-            ETHER_TOKEN.approve(proxyAddress, MAX_UINT);
-            ZRX_TOKEN.approve(proxyAddress, MAX_UINT);
-        }
-    }
+        MixinForwarderCore()
+    {}
 }
diff --git a/packages/contracts/src/2.0.0/forwarder/MixinConstants.sol b/packages/contracts/src/2.0.0/forwarder/MixinConstants.sol
index 18f2ba3bc..2b064d579 100644
--- a/packages/contracts/src/2.0.0/forwarder/MixinConstants.sol
+++ b/packages/contracts/src/2.0.0/forwarder/MixinConstants.sol
@@ -16,19 +16,14 @@
 
 */
 
-pragma solidity ^0.4.24;
+pragma solidity 0.4.24;
 
-import "../protocol/Exchange/Exchange.sol";
-import { WETH9 as EtherToken } from "../tokens/WETH9/WETH9.sol";
-import "../tokens/ERC20Token/IERC20Token.sol";
+import "./mixins/MConstants.sol";
 
-contract MixinConstants {
 
-    Exchange EXCHANGE;
-    EtherToken ETHER_TOKEN;
-    IERC20Token ZRX_TOKEN;
-    bytes ZRX_ASSET_DATA;
-    bytes WETH_ASSET_DATA;
+contract MixinConstants is
+    MConstants
+{
 
     constructor (
         address _exchange,
@@ -39,11 +34,10 @@ contract MixinConstants {
     )
         public
     {
-        EXCHANGE = Exchange(_exchange);
-        ETHER_TOKEN = EtherToken(_etherToken);
+        EXCHANGE = IExchange(_exchange);
+        ETHER_TOKEN = IEtherToken(_etherToken);
         ZRX_TOKEN = IERC20Token(_zrxToken);
         ZRX_ASSET_DATA = _zrxAssetData;
         WETH_ASSET_DATA = _wethAssetData;
     }
-
-}
\ No newline at end of file
+}
diff --git a/packages/contracts/src/2.0.0/forwarder/MixinERC721.sol b/packages/contracts/src/2.0.0/forwarder/MixinERC721.sol
deleted file mode 100644
index b2e8803a9..000000000
--- a/packages/contracts/src/2.0.0/forwarder/MixinERC721.sol
+++ /dev/null
@@ -1,64 +0,0 @@
-/*
-
-  Copyright 2018 ZeroEx Intl.
-
-  Licensed under the Apache License, Version 2.0 (the "License");
-  you may not use this file except in compliance with the License.
-  You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-  Unless required by applicable law or agreed to in writing, software
-  distributed under the License is distributed on an "AS IS" BASIS,
-  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-  See the License for the specific language governing permissions and
-  limitations under the License.
-
-*/
-
-pragma solidity ^0.4.24;
-pragma experimental ABIEncoderV2;
-
-import "../utils/LibBytes/LibBytes.sol";
-import "../tokens/ERC721Token/IERC721Token.sol";
-
-contract MixinERC721 {
-
-    using LibBytes for bytes;
-    bytes4 constant ERC721_RECEIVED = bytes4(keccak256("onERC721Received(address,uint256,bytes)"));
-    bytes4 constant ERC721_RECEIVED_OPERATOR = bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"));
-
-    function onERC721Received(address, uint256, bytes memory)
-        public
-        pure
-        returns(bytes4)
-    {
-        return ERC721_RECEIVED;
-    }
-
-    function onERC721Received(address, address, uint256, bytes memory)
-        public
-        pure
-        returns(bytes4)
-    {
-        return ERC721_RECEIVED_OPERATOR;
-    }
-
-    function transferERC721Token(
-        bytes memory assetData,
-        address to
-    )
-        internal
-    {
-        // Decode asset data.
-        address token = assetData.readAddress(16);
-        uint256 tokenId = assetData.readUint256(36);
-        bytes memory receiverData = assetData.readBytesWithLength(100);
-        IERC721Token(token).safeTransferFrom(
-            address(this),
-            to,
-            tokenId,
-            receiverData
-        );
-    }
-}
diff --git a/packages/contracts/src/2.0.0/forwarder/MixinErrorMessages.sol b/packages/contracts/src/2.0.0/forwarder/MixinErrorMessages.sol
index c2a6ea0a4..1b3e3f488 100644
--- a/packages/contracts/src/2.0.0/forwarder/MixinErrorMessages.sol
+++ b/packages/contracts/src/2.0.0/forwarder/MixinErrorMessages.sol
@@ -16,7 +16,9 @@
 
 */
 
-pragma solidity ^0.4.24;
+// solhint-disable
+pragma solidity 0.4.24;
+
 
 /// This contract is intended to serve as a reference, but is not actually used for efficiency reasons.
 contract MixinErrorMessages {
diff --git a/packages/contracts/src/2.0.0/forwarder/MixinExpectedResults.sol b/packages/contracts/src/2.0.0/forwarder/MixinExpectedResults.sol
index 0bca7dc80..a575c9675 100644
--- a/packages/contracts/src/2.0.0/forwarder/MixinExpectedResults.sol
+++ b/packages/contracts/src/2.0.0/forwarder/MixinExpectedResults.sol
@@ -16,106 +16,71 @@
 
 */
 
-pragma solidity ^0.4.24;
+pragma solidity 0.4.24;
 pragma experimental ABIEncoderV2;
 
 import "../utils/LibBytes/LibBytes.sol";
 import "../protocol/Exchange/libs/LibFillResults.sol";
 import "../protocol/Exchange/libs/LibMath.sol";
 import "../protocol/Exchange/libs/LibOrder.sol";
-import "./MixinConstants.sol";
+import "./mixins/MConstants.sol";
+import "./mixins/MExpectedResults.sol";
+
 
 contract MixinExpectedResults is
     LibMath,
     LibFillResults,
-    MixinConstants
+    MConstants,
+    MExpectedResults
 {
 
-    /// @dev Simulates the 0x Exchange fillOrder validation and calculations, without performing any state changes.
-    /// @param order An Order struct containing order specifications.
-    /// @param takerAssetFillAmount A number representing the amount of this order to fill.
-    /// @return fillResults Amounts filled and fees paid by maker and taker.
-    function calculateFillResults(
-        LibOrder.Order memory order,
-        uint256 takerAssetFillAmount
-    )
-        internal
-        view
-        returns (FillResults memory fillResults)
-    {
-        LibOrder.OrderInfo memory orderInfo = EXCHANGE.getOrderInfo(order);
-        if (orderInfo.orderStatus != uint8(LibOrder.OrderStatus.FILLABLE)) {
-            return fillResults;
-        }
-        uint256 remainingTakerAssetAmount = safeSub(order.takerAssetAmount, orderInfo.orderTakerAssetFilledAmount);
-        uint256 takerAssetFilledAmount = min256(takerAssetFillAmount, remainingTakerAssetAmount);
-
-        fillResults.takerAssetFilledAmount = takerAssetFilledAmount;
-        fillResults.makerAssetFilledAmount = getPartialAmount(
-            takerAssetFilledAmount,
-            order.takerAssetAmount,
-            order.makerAssetAmount
-        );
-        fillResults.makerFeePaid = getPartialAmount(
-            takerAssetFilledAmount,
-            order.takerAssetAmount,
-            order.makerFee
-        );
-        fillResults.takerFeePaid = getPartialAmount(
-            takerAssetFilledAmount,
-            order.takerAssetAmount,
-            order.takerFee
-        );
-        return fillResults;
-    }
-
-    /// @dev Calculates a FillResults total for selling takerAssetFillAmount over all orders. 
+    /// @dev Calculates a total FillResults for buying makerAssetFillAmount over all orders.
     ///      Including the fees required to be paid. 
     /// @param orders An array of Order struct containing order specifications.
-    /// @param takerAssetFillAmount A number representing the amount of this order to fill.
+    /// @param makerAssetFillAmount A number representing the amount of this order to fill.
     /// @return totalFillResults Amounts filled and fees paid by maker and taker.
-    function calculateMarketSellResults(
+    function calculateMarketBuyResults(
         LibOrder.Order[] memory orders,
-        uint256 takerAssetFillAmount
+        uint256 makerAssetFillAmount
     )
-        internal
+        public
         view
         returns (FillResults memory totalFillResults)
     {
         for (uint256 i = 0; i < orders.length; i++) {
-            uint256 remainingTakerAssetFillAmount = safeSub(takerAssetFillAmount, totalFillResults.takerAssetFilledAmount);
+            uint256 remainingMakerAssetFillAmount = safeSub(makerAssetFillAmount, totalFillResults.makerAssetFilledAmount);
+            uint256 remainingTakerAssetFillAmount = getPartialAmount(
+                orders[i].takerAssetAmount,
+                orders[i].makerAssetAmount,
+                remainingMakerAssetFillAmount
+            );
             FillResults memory singleFillResult = calculateFillResults(orders[i], remainingTakerAssetFillAmount);
             addFillResults(totalFillResults, singleFillResult);
-            if (totalFillResults.takerAssetFilledAmount == takerAssetFillAmount) {
+            if (totalFillResults.makerAssetFilledAmount == makerAssetFillAmount) {
                 break;
             }
         }
         return totalFillResults;
     }
 
-    /// @dev Calculates a total FillResults for buying makerAssetFillAmount over all orders.
+    /// @dev Calculates a FillResults total for selling takerAssetFillAmount over all orders. 
     ///      Including the fees required to be paid. 
     /// @param orders An array of Order struct containing order specifications.
-    /// @param makerAssetFillAmount A number representing the amount of this order to fill.
+    /// @param takerAssetFillAmount A number representing the amount of this order to fill.
     /// @return totalFillResults Amounts filled and fees paid by maker and taker.
-    function calculateMarketBuyResults(
+    function calculateMarketSellResults(
         LibOrder.Order[] memory orders,
-        uint256 makerAssetFillAmount
+        uint256 takerAssetFillAmount
     )
         public
         view
         returns (FillResults memory totalFillResults)
     {
         for (uint256 i = 0; i < orders.length; i++) {
-            uint256 remainingMakerAssetFillAmount = safeSub(makerAssetFillAmount, totalFillResults.makerAssetFilledAmount);
-            uint256 remainingTakerAssetFillAmount = getPartialAmount(
-                orders[i].takerAssetAmount,
-                orders[i].makerAssetAmount,
-                remainingMakerAssetFillAmount
-            );
+            uint256 remainingTakerAssetFillAmount = safeSub(takerAssetFillAmount, totalFillResults.takerAssetFilledAmount);
             FillResults memory singleFillResult = calculateFillResults(orders[i], remainingTakerAssetFillAmount);
             addFillResults(totalFillResults, singleFillResult);
-            if (totalFillResults.makerAssetFilledAmount == makerAssetFillAmount) {
+            if (totalFillResults.takerAssetFilledAmount == takerAssetFillAmount) {
                 break;
             }
         }
@@ -155,4 +120,42 @@ contract MixinExpectedResults is
         }
         return totalFillResults;
     }
+
+    /// @dev Simulates the 0x Exchange fillOrder validation and calculations, without performing any state changes.
+    /// @param order An Order struct containing order specifications.
+    /// @param takerAssetFillAmount A number representing the amount of this order to fill.
+    /// @return fillResults Amounts filled and fees paid by maker and taker.
+    function calculateFillResults(
+        LibOrder.Order memory order,
+        uint256 takerAssetFillAmount
+    )
+        internal
+        view
+        returns (FillResults memory fillResults)
+    {
+        LibOrder.OrderInfo memory orderInfo = EXCHANGE.getOrderInfo(order);
+        if (orderInfo.orderStatus != uint8(LibOrder.OrderStatus.FILLABLE)) {
+            return fillResults;
+        }
+        uint256 remainingTakerAssetAmount = safeSub(order.takerAssetAmount, orderInfo.orderTakerAssetFilledAmount);
+        uint256 takerAssetFilledAmount = min256(takerAssetFillAmount, remainingTakerAssetAmount);
+
+        fillResults.takerAssetFilledAmount = takerAssetFilledAmount;
+        fillResults.makerAssetFilledAmount = getPartialAmount(
+            takerAssetFilledAmount,
+            order.takerAssetAmount,
+            order.makerAssetAmount
+        );
+        fillResults.makerFeePaid = getPartialAmount(
+            takerAssetFilledAmount,
+            order.takerAssetAmount,
+            order.makerFee
+        );
+        fillResults.takerFeePaid = getPartialAmount(
+            takerAssetFilledAmount,
+            order.takerAssetAmount,
+            order.takerFee
+        );
+        return fillResults;
+    }
 }
diff --git a/packages/contracts/src/2.0.0/forwarder/MixinWethFees.sol b/packages/contracts/src/2.0.0/forwarder/MixinFees.sol
index 9206c5fe0..8ea00a1d5 100644
--- a/packages/contracts/src/2.0.0/forwarder/MixinWethFees.sol
+++ b/packages/contracts/src/2.0.0/forwarder/MixinFees.sol
@@ -16,21 +16,33 @@
 
 */
 
-pragma solidity ^0.4.24;
-pragma experimental ABIEncoderV2;
+pragma solidity 0.4.24;
 
-import { WETH9 as EtherToken } from "../tokens/WETH9/WETH9.sol";
 import "../protocol/Exchange/libs/LibMath.sol";
-import "./MixinConstants.sol";
+import "./mixins/MConstants.sol";
+import "./mixins/MFees.sol";
 
-contract MixinWethFees is
+
+contract MixinFees is
     LibMath,
-    MixinConstants
+    MConstants,
+    MFees
 {
 
-    uint16  constant public PERCENTAGE_DENOMINATOR = 10000; // 9800 == 98%, 10000 == 100%
-    uint16  constant public MAX_FEE = 1000; // 10%
-    uint16  constant public ALLOWABLE_EXCHANGE_PERCENTAGE = 9500; // 95%
+    uint16 constant public PERCENTAGE_DENOMINATOR = 10000; // 9800 == 98%, 10000 == 100%
+    uint16 constant public MAX_FEE = 1000; // 10%
+    uint16 constant public ALLOWABLE_EXCHANGE_PERCENTAGE = 9500; // 95%
+
+    /// @dev Default payabale function, this allows us to withdraw WETH
+    function ()
+        public
+        payable
+    {
+        require(
+            msg.sender == address(ETHER_TOKEN),
+            "DEFAULT_FUNCTION_WETH_CONTRACT_ONLY"
+        );
+    }
 
     /// @dev Pays the feeRecipient feeProportion of the total takerEthAmount, denominated in ETH
     /// @param takerEthAmount The total amount that was transacted in WETH, fees are calculated from this value.
diff --git a/packages/contracts/src/2.0.0/forwarder/MixinMarketBuyTokens.sol b/packages/contracts/src/2.0.0/forwarder/MixinForwarderCore.sol
index ef06fe519..eadeaf5ba 100644
--- a/packages/contracts/src/2.0.0/forwarder/MixinMarketBuyTokens.sol
+++ b/packages/contracts/src/2.0.0/forwarder/MixinForwarderCore.sol
@@ -16,28 +16,122 @@
 
 */
 
-pragma solidity ^0.4.24;
+pragma solidity 0.4.24;
 pragma experimental ABIEncoderV2;
 
 import "../utils/LibBytes/LibBytes.sol";
-import "./MixinWethFees.sol";
-import "./MixinMarketBuyZrx.sol";
-import "./MixinExpectedResults.sol";
-import "./MixinERC20.sol";
-import "./MixinERC721.sol";
-import "./MixinConstants.sol";
+import "./mixins/MFees.sol";
+import "./mixins/MMarketBuyZrx.sol";
+import "./mixins/MExpectedResults.sol";
+import "./mixins/MTransfer.sol";
+import "./mixins/MConstants.sol";
+import "./mixins/MForwarderCore.sol";
 import "../protocol/Exchange/libs/LibOrder.sol";
+import "../protocol/Exchange/libs/LibFillResults.sol";
 
-contract MixinMarketBuyTokens is
-    MixinConstants,
-    MixinWethFees,
-    MixinMarketBuyZrx,
-    MixinExpectedResults,
-    MixinERC20,
-    MixinERC721
+
+contract MixinForwarderCore is
+    LibFillResults,
+    MConstants,
+    MExpectedResults,
+    MFees,
+    MMarketBuyZrx,
+    MTransfer,
+    MForwarderCore
 {
-    bytes4 public constant ERC20_DATA_ID = bytes4(keccak256("ERC20Token(address)"));
-    bytes4 public constant ERC721_DATA_ID = bytes4(keccak256("ERC721Token(address,uint256,bytes)"));
+    bytes4 constant internal ERC20_DATA_ID = bytes4(keccak256("ERC20Token(address)"));
+    bytes4 constant internal ERC721_DATA_ID = bytes4(keccak256("ERC721Token(address,uint256,bytes)"));
+    uint256 constant internal MAX_UINT = 2**256 - 1;
+
+    constructor ()
+        public
+    {
+        address proxyAddress = EXCHANGE.getAssetProxy(ERC20_DATA_ID);
+        if (proxyAddress != address(0)) {
+            ETHER_TOKEN.approve(proxyAddress, MAX_UINT);
+            ZRX_TOKEN.approve(proxyAddress, MAX_UINT);
+        }
+    }
+
+    /// @dev Market sells ETH for ERC20 tokens, performing fee abstraction if required. This does not support ERC721 tokens. This function is payable
+    ///      and will convert all incoming ETH into WETH and perform the trade on behalf of the caller.
+    ///      This function allows for a deduction of a proportion of incoming ETH sent to the feeRecipient.
+    ///      The caller is sent all tokens from the operation.
+    ///      If the purchased token amount does not meet an acceptable threshold then this function reverts.
+    /// @param orders An array of Order struct containing order specifications.
+    /// @param signatures An array of Proof that order has been created by maker.
+    /// @param feeOrders An array of Order struct containing order specifications for fees.
+    /// @param feeSignatures An array of Proof that order has been created by maker for the fee orders.
+    /// @param feeProportion A proportion deducted off the incoming ETH and sent to feeRecipient. The maximum value for this
+    ///        is 1000, aka 10%. Supports up to 2 decimal places. I.e 0.59% is 59.
+    /// @param feeRecipient An address of the fee recipient whom receives feeProportion of ETH.
+    /// @return FillResults amounts filled and fees paid by maker and taker.
+    function marketSellEthForERC20(
+        LibOrder.Order[] memory orders,
+        bytes[] memory signatures,
+        LibOrder.Order[] memory feeOrders,
+        bytes[] memory feeSignatures,
+        uint16  feeProportion,
+        address feeRecipient
+    )
+        public
+        payable
+        returns (FillResults memory totalFillResults)
+    {
+        uint256 takerEthAmount = msg.value;
+        require(
+            takerEthAmount > 0,
+            "VALUE_GREATER_THAN_ZERO"
+        );
+        // Deduct the fee from the total amount of ETH sent in
+        uint256 ethFeeAmount = payEthFee(
+            takerEthAmount,
+            feeProportion,
+            feeRecipient
+        );
+        uint256 wethSellAmount = safeSub(takerEthAmount, ethFeeAmount);
+
+        // Deposit the remaining to be used for trading
+        ETHER_TOKEN.deposit.value(wethSellAmount)();
+        // Populate the known assetData, as it is always WETH the caller can provide null bytes to save gas
+        // marketSellOrders fills the remaining
+        address makerTokenAddress = LibBytes.readAddress(orders[0].makerAssetData, 16);
+        orders[0].takerAssetData = WETH_ASSET_DATA;
+        if (makerTokenAddress == address(ZRX_TOKEN)) {
+            // If this is ZRX then we market sell from the orders, rather than a 2 step of buying ZRX fees from feeOrders
+            // then buying ZRX from orders
+            totalFillResults = marketSellEthForZRXInternal(
+                orders,
+                signatures,
+                wethSellAmount
+            );
+        } else {
+            totalFillResults = marketSellEthForERC20Internal(
+                orders,
+                signatures,
+                feeOrders,
+                feeSignatures,
+                wethSellAmount
+            );
+        }
+        // Prevent accidental WETH owned by this contract and it being spent
+        require(
+            takerEthAmount >= totalFillResults.takerAssetFilledAmount,
+            "INVALID_MSG_VALUE"
+        );
+        // Ensure no WETH is left in this contract
+        require(
+            wethSellAmount == totalFillResults.takerAssetFilledAmount,
+            "UNACCEPTABLE_THRESHOLD"
+        );
+        // Transfer all tokens to msg.sender
+        transferERC20Token(
+            makerTokenAddress,
+            msg.sender,
+            totalFillResults.makerAssetFilledAmount
+        );
+        return totalFillResults;
+    }
 
     /// @dev Buys the exact amount of assets (ERC20 and ERC721), performing fee abstraction if required.
     ///      All order assets must be of the same type. Deducts a proportional fee to fee recipient.
@@ -62,8 +156,8 @@ contract MixinMarketBuyTokens is
         uint16  feeProportion,
         address feeRecipient
     )
-        payable
         public
+        payable
         returns (FillResults memory totalFillResults)
     {
         uint256 takerEthAmount = msg.value;
@@ -112,6 +206,85 @@ contract MixinMarketBuyTokens is
         return totalFillResults;
     }
 
+    /// @dev Market sells WETH for ERC20 tokens.
+    /// @param orders An array of Order struct containing order specifications.
+    /// @param signatures An array of Proof that order has been created by maker.
+    /// @param feeOrders An array of Order struct containing order specifications for fees.
+    /// @param feeSignatures An array of Proof that order has been created by maker for the fee orders.
+    /// @param wethSellAmount The amount of WETH to sell.
+    /// @return FillResults amounts filled and fees paid by maker and taker.
+    function marketSellEthForERC20Internal(
+        LibOrder.Order[] memory orders,
+        bytes[] memory signatures,
+        LibOrder.Order[] memory feeOrders,
+        bytes[] memory feeSignatures,
+        uint256 wethSellAmount
+    )
+        internal
+        returns (FillResults memory totalFillResults)
+    {
+        uint256 remainingWethSellAmount = wethSellAmount;
+        FillResults memory calculatedMarketSellResults = calculateMarketSellResults(orders, wethSellAmount);
+        if (calculatedMarketSellResults.takerFeePaid > 0) {
+            // Fees are required for these orders. Buy enough ZRX to cover the future market buy
+            FillResults memory feeTokensResults = marketBuyZrxInternal(
+                feeOrders,
+                feeSignatures,
+                calculatedMarketSellResults.takerFeePaid
+            );
+            // Ensure the token abstraction was fair if fees were proportionally too high, we fail
+            require(
+                isAcceptableThreshold(
+                    wethSellAmount,
+                    safeSub(wethSellAmount, feeTokensResults.takerAssetFilledAmount)
+                ),
+                "UNACCEPTABLE_THRESHOLD"
+            );
+            remainingWethSellAmount = safeSub(remainingWethSellAmount, feeTokensResults.takerAssetFilledAmount);
+            totalFillResults.takerFeePaid = feeTokensResults.takerFeePaid;
+            totalFillResults.takerAssetFilledAmount = feeTokensResults.takerAssetFilledAmount;
+        }
+        // Make our market sell to buy the requested tokens with the remaining balance
+        FillResults memory requestedTokensResults = EXCHANGE.marketSellOrders(
+            orders,
+            remainingWethSellAmount,
+            signatures
+        );
+        // Update our return FillResult with the market sell
+        addFillResults(totalFillResults, requestedTokensResults);
+        return totalFillResults;
+    }
+
+    /// @dev Market sells WETH for ZRX tokens.
+    /// @param orders An array of Order struct containing order specifications.
+    /// @param signatures An array of Proof that order has been created by maker.
+    /// @param wethSellAmount The amount of WETH to sell.
+    /// @return FillResults amounts filled and fees paid by maker and taker.
+    function marketSellEthForZRXInternal(
+        LibOrder.Order[] memory orders,
+        bytes[] memory signatures,
+        uint256 wethSellAmount
+    )
+        internal
+        returns (FillResults memory totalFillResults)
+    {
+        // Make our market sell to buy the requested tokens with the remaining balance
+        totalFillResults = EXCHANGE.marketSellOrders(
+            orders,
+            wethSellAmount,
+            signatures
+        );
+        // Exchange does not special case ZRX in the makerAssetFilledAmount, if fees were deducted then using this amount
+        // for future transfers is invalid.
+        uint256 zrxAmountBought = safeSub(totalFillResults.makerAssetFilledAmount, totalFillResults.takerFeePaid);
+        require(
+            isAcceptableThreshold(totalFillResults.makerAssetFilledAmount, zrxAmountBought),
+            "UNACCEPTABLE_THRESHOLD"
+        );
+        totalFillResults.makerAssetFilledAmount = zrxAmountBought;
+        return totalFillResults;
+    }
+
     /// @dev Buys an exact amount of an ERC20 token using WETH.
     /// @param orders Orders to fill. The maker asset is the ERC20 token to buy. The taker asset is WETH.
     /// @param signatures Proof that the orders were created by their respective makers.
@@ -126,8 +299,8 @@ contract MixinMarketBuyTokens is
         bytes[] memory feeSignatures,
         uint256 makerTokenFillAmount
     )
-        private
-        returns (FillResults memory totalFillResults)
+        internal
+        returns (LibFillResults.FillResults memory totalFillResults)
     {
         // We read the maker token address to check if it is ZRX and later use it for transfer
         address makerTokenAddress = LibBytes.readAddress(orders[0].makerAssetData, 16);
@@ -188,7 +361,7 @@ contract MixinMarketBuyTokens is
             );
         }
         // Transfer all purchased tokens to msg.sender
-        transferToken(
+        transferERC20Token(
             makerTokenAddress,
             msg.sender,
             marketBuyResults.makerAssetFilledAmount
@@ -208,8 +381,8 @@ contract MixinMarketBuyTokens is
         LibOrder.Order[] memory feeOrders,
         bytes[] memory feeSignatures
     )
-        private
-        returns (FillResults memory totalFillResults)
+        internal
+        returns (LibFillResults.FillResults memory totalFillResults)
     {
         uint256 totalZrxFeeAmount;
         uint256 ordersLength = orders.length;
diff --git a/packages/contracts/src/2.0.0/forwarder/MixinMarketBuyZrx.sol b/packages/contracts/src/2.0.0/forwarder/MixinMarketBuyZrx.sol
index 4dbb34de3..e272f8aad 100644
--- a/packages/contracts/src/2.0.0/forwarder/MixinMarketBuyZrx.sol
+++ b/packages/contracts/src/2.0.0/forwarder/MixinMarketBuyZrx.sol
@@ -16,20 +16,23 @@
 
 */
 
-pragma solidity ^0.4.24;
+pragma solidity 0.4.24;
 pragma experimental ABIEncoderV2;
 
-import "../protocol/Exchange/Exchange.sol";
 import "../protocol/Exchange/libs/LibFillResults.sol";
 import "../protocol/Exchange/libs/LibOrder.sol";
 import "../protocol/Exchange/libs/LibMath.sol";
-import "./MixinConstants.sol";
+import "./mixins/MConstants.sol";
+import "./mixins/MMarketBuyZrx.sol";
+
 
 contract MixinMarketBuyZrx is
     LibMath,
     LibFillResults,
-    MixinConstants
+    MConstants,
+    MMarketBuyZrx
 {
+
     /// @dev Buys zrxBuyAmount of ZRX fee tokens, taking into account the fees on buying fee tokens. This will guarantee
     ///      At least zrxBuyAmount of ZRX fee tokens are purchased (sometimes slightly over due to rounding issues).
     ///      It is possible that a request to buy 200 ZRX fee tokens will require purchasing 202 ZRX tokens
diff --git a/packages/contracts/src/2.0.0/forwarder/MixinMarketSellTokens.sol b/packages/contracts/src/2.0.0/forwarder/MixinMarketSellTokens.sol
deleted file mode 100644
index 8c9cdb8d5..000000000
--- a/packages/contracts/src/2.0.0/forwarder/MixinMarketSellTokens.sol
+++ /dev/null
@@ -1,196 +0,0 @@
-/*
-
-  Copyright 2018 ZeroEx Intl.
-
-  Licensed under the Apache License, Version 2.0 (the "License");
-  you may not use this file except in compliance with the License.
-  You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-  Unless required by applicable law or agreed to in writing, software
-  distributed under the License is distributed on an "AS IS" BASIS,
-  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-  See the License for the specific language governing permissions and
-  limitations under the License.
-
-*/
-
-pragma solidity ^0.4.24;
-pragma experimental ABIEncoderV2;
-
-import "../protocol/Exchange/libs/LibOrder.sol";
-import "../utils/LibBytes/LibBytes.sol";
-import "./MixinWethFees.sol";
-import "./MixinExpectedResults.sol";
-import "./MixinERC20.sol";
-import "./MixinConstants.sol";
-import "./MixinMarketBuyZrx.sol";
-
-contract MixinMarketSellTokens is
-    MixinConstants,
-    MixinWethFees,
-    MixinMarketBuyZrx,
-    MixinExpectedResults,
-    MixinERC20
-{
-    /// @dev Market sells ETH for ERC20 tokens, performing fee abstraction if required. This does not support ERC721 tokens. This function is payable
-    ///      and will convert all incoming ETH into WETH and perform the trade on behalf of the caller.
-    ///      This function allows for a deduction of a proportion of incoming ETH sent to the feeRecipient.
-    ///      The caller is sent all tokens from the operation.
-    ///      If the purchased token amount does not meet an acceptable threshold then this function reverts.
-    /// @param orders An array of Order struct containing order specifications.
-    /// @param signatures An array of Proof that order has been created by maker.
-    /// @param feeOrders An array of Order struct containing order specifications for fees.
-    /// @param feeSignatures An array of Proof that order has been created by maker for the fee orders.
-    /// @param feeProportion A proportion deducted off the incoming ETH and sent to feeRecipient. The maximum value for this
-    ///        is 1000, aka 10%. Supports up to 2 decimal places. I.e 0.59% is 59.
-    /// @param feeRecipient An address of the fee recipient whom receives feeProportion of ETH.
-    /// @return FillResults amounts filled and fees paid by maker and taker.
-    function marketSellEthForERC20(
-        LibOrder.Order[] memory orders,
-        bytes[] memory signatures,
-        LibOrder.Order[] memory feeOrders,
-        bytes[] memory feeSignatures,
-        uint16  feeProportion,
-        address feeRecipient
-    )
-        payable
-        public
-        returns (FillResults memory totalFillResults)
-    {
-        uint256 takerEthAmount = msg.value;
-        require(
-            takerEthAmount > 0,
-            "VALUE_GREATER_THAN_ZERO"
-        );
-        // Deduct the fee from the total amount of ETH sent in
-        uint256 ethFeeAmount = payEthFee(
-            takerEthAmount,
-            feeProportion,
-            feeRecipient
-        );
-        uint256 wethSellAmount = safeSub(takerEthAmount, ethFeeAmount);
-
-        // Deposit the remaining to be used for trading
-        ETHER_TOKEN.deposit.value(wethSellAmount)();
-        // Populate the known assetData, as it is always WETH the caller can provide null bytes to save gas
-        // marketSellOrders fills the remaining
-        address makerTokenAddress = LibBytes.readAddress(orders[0].makerAssetData, 16);
-        orders[0].takerAssetData = WETH_ASSET_DATA;
-        if (makerTokenAddress == address(ZRX_TOKEN)) {
-            // If this is ZRX then we market sell from the orders, rather than a 2 step of buying ZRX fees from feeOrders
-            // then buying ZRX from orders
-            totalFillResults = marketSellEthForZRXInternal(
-                orders,
-                signatures,
-                wethSellAmount
-            );
-        } else {
-            totalFillResults = marketSellEthForERC20Internal(
-                orders,
-                signatures,
-                feeOrders,
-                feeSignatures,
-                wethSellAmount
-            );
-        }
-        // Prevent accidental WETH owned by this contract and it being spent
-        require(
-            takerEthAmount >= totalFillResults.takerAssetFilledAmount,
-            "INVALID_MSG_VALUE"
-        );
-        // Ensure no WETH is left in this contract
-        require(
-            wethSellAmount == totalFillResults.takerAssetFilledAmount,
-            "UNACCEPTABLE_THRESHOLD"
-        );
-        // Transfer all tokens to msg.sender
-        transferToken(
-            makerTokenAddress,
-            msg.sender,
-            totalFillResults.makerAssetFilledAmount
-        );
-        return totalFillResults;
-    }
-
-    /// @dev Market sells WETH for ERC20 tokens.
-    /// @param orders An array of Order struct containing order specifications.
-    /// @param signatures An array of Proof that order has been created by maker.
-    /// @param feeOrders An array of Order struct containing order specifications for fees.
-    /// @param feeSignatures An array of Proof that order has been created by maker for the fee orders.
-    /// @param wethSellAmount The amount of WETH to sell.
-    /// @return FillResults amounts filled and fees paid by maker and taker.
-    function marketSellEthForERC20Internal(
-        LibOrder.Order[] memory orders,
-        bytes[] memory signatures,
-        LibOrder.Order[] memory feeOrders,
-        bytes[] memory feeSignatures,
-        uint256 wethSellAmount
-    )
-        internal
-        returns (FillResults memory totalFillResults)
-    {
-        uint256 remainingWethSellAmount = wethSellAmount;
-        FillResults memory calculatedMarketSellResults = calculateMarketSellResults(orders, wethSellAmount);
-        if (calculatedMarketSellResults.takerFeePaid > 0) {
-            // Fees are required for these orders. Buy enough ZRX to cover the future market buy
-            FillResults memory feeTokensResults = marketBuyZrxInternal(
-                feeOrders,
-                feeSignatures,
-                calculatedMarketSellResults.takerFeePaid
-            );
-            // Ensure the token abstraction was fair if fees were proportionally too high, we fail
-            require(
-                isAcceptableThreshold(
-                    wethSellAmount,
-                    safeSub(wethSellAmount, feeTokensResults.takerAssetFilledAmount)
-                ),
-                "UNACCEPTABLE_THRESHOLD"
-            );
-            remainingWethSellAmount = safeSub(remainingWethSellAmount, feeTokensResults.takerAssetFilledAmount);
-            totalFillResults.takerFeePaid = feeTokensResults.takerFeePaid;
-            totalFillResults.takerAssetFilledAmount = feeTokensResults.takerAssetFilledAmount;
-        }
-        // Make our market sell to buy the requested tokens with the remaining balance
-        FillResults memory requestedTokensResults = EXCHANGE.marketSellOrders(
-            orders,
-            remainingWethSellAmount,
-            signatures
-        );
-        // Update our return FillResult with the market sell
-        addFillResults(totalFillResults, requestedTokensResults);
-        return totalFillResults;
-    }
-
-    /// @dev Market sells WETH for ZRX tokens.
-    /// @param orders An array of Order struct containing order specifications.
-    /// @param signatures An array of Proof that order has been created by maker.
-    /// @param wethSellAmount The amount of WETH to sell.
-    /// @return FillResults amounts filled and fees paid by maker and taker.
-    function marketSellEthForZRXInternal(
-        LibOrder.Order[] memory orders,
-        bytes[] memory signatures,
-        uint256 wethSellAmount
-    )
-        internal
-        returns (FillResults memory totalFillResults)
-    {
-        // Make our market sell to buy the requested tokens with the remaining balance
-        totalFillResults = EXCHANGE.marketSellOrders(
-            orders,
-            wethSellAmount,
-            signatures
-        );
-        // Exchange does not special case ZRX in the makerAssetFilledAmount, if fees were deducted then using this amount
-        // for future transfers is invalid.
-        uint256 zrxAmountBought = safeSub(totalFillResults.makerAssetFilledAmount, totalFillResults.takerFeePaid);
-        require(
-            isAcceptableThreshold(totalFillResults.makerAssetFilledAmount, zrxAmountBought),
-            "UNACCEPTABLE_THRESHOLD"
-        );
-        totalFillResults.makerAssetFilledAmount = zrxAmountBought;
-        return totalFillResults;
-    }
-
-}
diff --git a/packages/contracts/src/2.0.0/forwarder/MixinERC20.sol b/packages/contracts/src/2.0.0/forwarder/MixinTransfer.sol
index 53d4116d7..6c49330f2 100644
--- a/packages/contracts/src/2.0.0/forwarder/MixinERC20.sol
+++ b/packages/contracts/src/2.0.0/forwarder/MixinTransfer.sol
@@ -16,15 +16,49 @@
 
 */
 
-pragma solidity ^0.4.24;
-pragma experimental ABIEncoderV2;
+pragma solidity 0.4.24;
 
-contract MixinERC20 {
+import "../utils/LibBytes/LibBytes.sol";
+import "../tokens/ERC721Token/IERC721Token.sol";
+import "./mixins/MTransfer.sol";
 
-    string constant ERROR_TRANSFER_FAILED = "TRANSFER_FAILED";
-    bytes4 constant ERC20_TRANSFER_SELECTOR = bytes4(keccak256("transfer(address,uint256)"));
 
-    function transferToken(
+contract MixinTransfer is
+    MTransfer
+{
+
+    using LibBytes for bytes;
+
+    bytes4 constant internal ERC20_TRANSFER_SELECTOR = bytes4(keccak256("transfer(address,uint256)"));
+    bytes4 constant internal ERC721_RECEIVED = bytes4(keccak256("onERC721Received(address,uint256,bytes)"));
+    bytes4 constant internal ERC721_RECEIVED_OPERATOR = bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"));
+
+    function onERC721Received(
+        address,
+        uint256,
+        bytes memory
+    )
+        public
+        pure
+        returns(bytes4)
+    {
+        return ERC721_RECEIVED;
+    }
+
+    function onERC721Received(
+        address,
+        address,
+        uint256,
+        bytes memory
+    )
+        public
+        pure
+        returns(bytes4)
+    {
+        return ERC721_RECEIVED_OPERATOR;
+    }
+
+    function transferERC20Token(
         address token,
         address to,
         uint256 amount
@@ -65,4 +99,22 @@ contract MixinERC20 {
             "TRANSFER_FAILED"
         );
     }
+
+    function transferERC721Token(
+        bytes memory assetData,
+        address to
+    )
+        internal
+    {
+        // Decode asset data.
+        address token = assetData.readAddress(16);
+        uint256 tokenId = assetData.readUint256(36);
+        bytes memory receiverData = assetData.readBytesWithLength(100);
+        IERC721Token(token).safeTransferFrom(
+            address(this),
+            to,
+            tokenId,
+            receiverData
+        );
+    }
 }
diff --git a/packages/contracts/src/2.0.0/forwarder/interfaces/IExpectedResults.sol b/packages/contracts/src/2.0.0/forwarder/interfaces/IExpectedResults.sol
new file mode 100644
index 000000000..89187b750
--- /dev/null
+++ b/packages/contracts/src/2.0.0/forwarder/interfaces/IExpectedResults.sol
@@ -0,0 +1,66 @@
+/*
+
+  Copyright 2018 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity 0.4.24;
+pragma experimental ABIEncoderV2;
+
+import "../../protocol/Exchange/libs/LibFillResults.sol";
+import "../../protocol/Exchange/libs/LibOrder.sol";
+
+
+contract IExpectedResults {
+
+    /// @dev Calculates a total FillResults for buying makerAssetFillAmount over all orders.
+    ///      Including the fees required to be paid. 
+    /// @param orders An array of Order struct containing order specifications.
+    /// @param makerAssetFillAmount A number representing the amount of this order to fill.
+    /// @return totalFillResults Amounts filled and fees paid by maker and taker.
+    function calculateMarketBuyResults(
+        LibOrder.Order[] memory orders,
+        uint256 makerAssetFillAmount
+    )
+        public
+        view
+        returns (LibFillResults.FillResults memory totalFillResults);
+
+    /// @dev Calculates a FillResults total for selling takerAssetFillAmount over all orders. 
+    ///      Including the fees required to be paid. 
+    /// @param orders An array of Order struct containing order specifications.
+    /// @param takerAssetFillAmount A number representing the amount of this order to fill.
+    /// @return totalFillResults Amounts filled and fees paid by maker and taker.
+    function calculateMarketSellResults(
+        LibOrder.Order[] memory orders,
+        uint256 takerAssetFillAmount
+    )
+        public
+        view
+        returns (LibFillResults.FillResults memory totalFillResults);
+
+    /// @dev Calculates fill results for buyFeeTokens. This handles fees on buying ZRX
+    ///      so the end result is the expected amount of ZRX (not less after fees).
+    /// @param orders An array of Order struct containing order specifications.
+    /// @param zrxFillAmount A number representing the amount zrx to buy
+    /// @return totalFillResults Expected fill result amounts from buying fees
+    function calculateMarketBuyZrxResults(
+        LibOrder.Order[] memory orders,
+        uint256 zrxFillAmount
+    )
+        public
+        view
+        returns (LibFillResults.FillResults memory totalFillResults);
+}
diff --git a/packages/contracts/src/2.0.0/forwarder/interfaces/IForwarder.sol b/packages/contracts/src/2.0.0/forwarder/interfaces/IForwarder.sol
new file mode 100644
index 000000000..745dd29a9
--- /dev/null
+++ b/packages/contracts/src/2.0.0/forwarder/interfaces/IForwarder.sol
@@ -0,0 +1,30 @@
+/*
+
+  Copyright 2018 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity 0.4.24;
+pragma experimental ABIEncoderV2;
+
+import "./IForwarderCore.sol";
+import "./IExpectedResults.sol";
+
+
+// solhint-disable no-empty-blocks
+contract IForwarder is
+    IForwarderCore,
+    IExpectedResults
+{}
diff --git a/packages/contracts/src/2.0.0/forwarder/interfaces/IForwarderCore.sol b/packages/contracts/src/2.0.0/forwarder/interfaces/IForwarderCore.sol
new file mode 100644
index 000000000..7ac2a8af3
--- /dev/null
+++ b/packages/contracts/src/2.0.0/forwarder/interfaces/IForwarderCore.sol
@@ -0,0 +1,79 @@
+/*
+
+  Copyright 2018 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity 0.4.24;
+pragma experimental ABIEncoderV2;
+
+import "../../protocol/Exchange/libs/LibOrder.sol";
+import "../../protocol/Exchange/libs/LibFillResults.sol";
+
+
+contract IForwarderCore {
+
+    /// @dev Market sells ETH for ERC20 tokens, performing fee abstraction if required. This does not support ERC721 tokens. This function is payable
+    ///      and will convert all incoming ETH into WETH and perform the trade on behalf of the caller.
+    ///      This function allows for a deduction of a proportion of incoming ETH sent to the feeRecipient.
+    ///      The caller is sent all tokens from the operation.
+    ///      If the purchased token amount does not meet an acceptable threshold then this function reverts.
+    /// @param orders An array of Order struct containing order specifications.
+    /// @param signatures An array of Proof that order has been created by maker.
+    /// @param feeOrders An array of Order struct containing order specifications for fees.
+    /// @param feeSignatures An array of Proof that order has been created by maker for the fee orders.
+    /// @param feeProportion A proportion deducted off the incoming ETH and sent to feeRecipient. The maximum value for this
+    ///        is 1000, aka 10%. Supports up to 2 decimal places. I.e 0.59% is 59.
+    /// @param feeRecipient An address of the fee recipient whom receives feeProportion of ETH.
+    /// @return FillResults amounts filled and fees paid by maker and taker.
+    function marketSellEthForERC20(
+        LibOrder.Order[] memory orders,
+        bytes[] memory signatures,
+        LibOrder.Order[] memory feeOrders,
+        bytes[] memory feeSignatures,
+        uint16  feeProportion,
+        address feeRecipient
+    )
+        public
+        payable
+        returns (LibFillResults.FillResults memory totalFillResults);
+
+    /// @dev Buys the exact amount of assets (ERC20 and ERC721), performing fee abstraction if required.
+    ///      All order assets must be of the same type. Deducts a proportional fee to fee recipient.
+    ///      This function is payable and will convert all incoming ETH into WETH and perform the trade on behalf of the caller.
+    ///      The caller is sent all assets from the fill of orders. This function will revert unless the requested amount of assets are purchased.
+    ///      Any excess ETH sent will be returned to the caller
+    /// @param orders An array of Order struct containing order specifications.
+    /// @param signatures An array of Proof that order has been created by maker.
+    /// @param feeOrders An array of Order struct containing order specifications for fees.
+    /// @param makerTokenFillAmount The amount of maker asset to buy.
+    /// @param feeSignatures An array of Proof that order has been created by maker for the fee orders.
+    /// @param feeProportion A proportion deducted off the ETH spent and sent to feeRecipient. The maximum value for this
+    ///        is 1000, aka 10%. Supports up to 2 decimal places. I.e 0.59% is 59.
+    /// @param feeRecipient An address of the fee recipient whom receives feeProportion of ETH.
+    /// @return FillResults amounts filled and fees paid by maker and taker.
+    function marketBuyTokensWithEth(
+        LibOrder.Order[] memory orders,
+        bytes[] memory signatures,
+        LibOrder.Order[] memory feeOrders,
+        bytes[] memory feeSignatures,
+        uint256 makerTokenFillAmount,
+        uint16  feeProportion,
+        address feeRecipient
+    )
+        public
+        payable
+        returns (LibFillResults.FillResults memory totalFillResults);
+}
diff --git a/packages/contracts/src/2.0.0/forwarder/mixins/MConstants.sol b/packages/contracts/src/2.0.0/forwarder/mixins/MConstants.sol
new file mode 100644
index 000000000..348bf169e
--- /dev/null
+++ b/packages/contracts/src/2.0.0/forwarder/mixins/MConstants.sol
@@ -0,0 +1,35 @@
+/*
+
+  Copyright 2018 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity 0.4.24;
+
+import "../../protocol/Exchange/interfaces/IExchange.sol";
+import "../../tokens/EtherToken/IEtherToken.sol";
+import "../../tokens/ERC20Token/IERC20Token.sol";
+
+
+contract MConstants {
+
+    // solhint-disable var-name-mixedcase
+    IExchange internal EXCHANGE;
+    IEtherToken internal ETHER_TOKEN;
+    IERC20Token internal ZRX_TOKEN;
+    bytes internal ZRX_ASSET_DATA;
+    bytes internal WETH_ASSET_DATA;
+    // solhint-enable var-name-mixedcase
+}
diff --git a/packages/contracts/src/2.0.0/forwarder/mixins/MExpectedResults.sol b/packages/contracts/src/2.0.0/forwarder/mixins/MExpectedResults.sol
new file mode 100644
index 000000000..cf03bb32e
--- /dev/null
+++ b/packages/contracts/src/2.0.0/forwarder/mixins/MExpectedResults.sol
@@ -0,0 +1,42 @@
+/*
+
+  Copyright 2018 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity 0.4.24;
+pragma experimental ABIEncoderV2;
+
+import "../../protocol/Exchange/libs/LibFillResults.sol";
+import "../../protocol/Exchange/libs/LibOrder.sol";
+import "../interfaces/IExpectedResults.sol";
+
+
+contract MExpectedResults is
+    IExpectedResults
+{
+
+    /// @dev Simulates the 0x Exchange fillOrder validation and calculations, without performing any state changes.
+    /// @param order An Order struct containing order specifications.
+    /// @param takerAssetFillAmount A number representing the amount of this order to fill.
+    /// @return fillResults Amounts filled and fees paid by maker and taker.
+    function calculateFillResults(
+        LibOrder.Order memory order,
+        uint256 takerAssetFillAmount
+    )
+        internal
+        view
+        returns (LibFillResults.FillResults memory fillResults);
+}
diff --git a/packages/contracts/src/2.0.0/forwarder/mixins/MFees.sol b/packages/contracts/src/2.0.0/forwarder/mixins/MFees.sol
new file mode 100644
index 000000000..f332637ea
--- /dev/null
+++ b/packages/contracts/src/2.0.0/forwarder/mixins/MFees.sol
@@ -0,0 +1,63 @@
+/*
+
+  Copyright 2018 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity 0.4.24;
+
+
+contract MFees {
+
+    /// @dev Pays the feeRecipient feeProportion of the total takerEthAmount, denominated in ETH
+    /// @param takerEthAmount The total amount that was transacted in WETH, fees are calculated from this value.
+    /// @param feeProportion The proportion of fees
+    /// @param feeRecipient The recipient of the fees
+    /// @return ethFeeAmount Amount of ETH paid to feeRecipient as fee.
+    function payEthFee(
+        uint256 takerEthAmount,
+        uint16 feeProportion,
+        address feeRecipient
+    )
+        internal
+        returns (uint256 ethFeeAmount);
+
+    /// @dev Withdraws the remaining WETH, deduct and pay fees from this amount based on the takerTokenAmount to the feeRecipient.
+    ///      If a user overpaid ETH initially, the fees are calculated from the amount traded and deducted from withdrawAmount.
+    ///      Any remaining ETH is sent back to the user.
+    /// @param ethWithdrawAmount The amount to withdraw from the WETH contract.
+    /// @param wethAmountSold The total amount that was transacted in WETH, fees are calculated from this value.
+    /// @param feeProportion The proportion of fees
+    /// @param feeRecipient The recipient of the fees
+    function withdrawPayAndDeductEthFee(
+        uint256 ethWithdrawAmount,
+        uint256 wethAmountSold,
+        uint16 feeProportion,
+        address feeRecipient
+    )
+        internal;
+
+    /// @dev Checks whether the amount of tokens sold against the amount of tokens requested
+    ///      is within a certain threshold. This ensures the caller gets a fair deal when
+    ///      performing any token fee abstraction. Threshold is 95%. If fee abstraction costs more than
+    ///      5% of the total transaction, we return false.
+    /// @param requestedSellAmount The amount the user requested, or sent in to a payable function
+    /// @param tokenAmountSold The amount of the token that was sold after fee abstraction
+    /// @return bool of whether this is within an acceptable threshold
+    function isAcceptableThreshold(uint256 requestedSellAmount, uint256 tokenAmountSold)
+        internal
+        pure
+        returns (bool);
+}
diff --git a/packages/contracts/src/2.0.0/forwarder/mixins/MForwarderCore.sol b/packages/contracts/src/2.0.0/forwarder/mixins/MForwarderCore.sol
new file mode 100644
index 000000000..4a54e76b1
--- /dev/null
+++ b/packages/contracts/src/2.0.0/forwarder/mixins/MForwarderCore.sol
@@ -0,0 +1,92 @@
+/*
+
+  Copyright 2018 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity 0.4.24;
+pragma experimental ABIEncoderV2;
+
+import "../../protocol/Exchange/libs/LibOrder.sol";
+import "../../protocol/Exchange/libs/LibFillResults.sol";
+import "../interfaces/IForwarderCore.sol";
+
+
+contract MForwarderCore is
+    IForwarderCore
+{
+
+    /// @dev Market sells WETH for ERC20 tokens.
+    /// @param orders An array of Order struct containing order specifications.
+    /// @param signatures An array of Proof that order has been created by maker.
+    /// @param feeOrders An array of Order struct containing order specifications for fees.
+    /// @param feeSignatures An array of Proof that order has been created by maker for the fee orders.
+    /// @param wethSellAmount The amount of WETH to sell.
+    /// @return FillResults amounts filled and fees paid by maker and taker.
+    function marketSellEthForERC20Internal(
+        LibOrder.Order[] memory orders,
+        bytes[] memory signatures,
+        LibOrder.Order[] memory feeOrders,
+        bytes[] memory feeSignatures,
+        uint256 wethSellAmount
+    )
+        internal
+        returns (LibFillResults.FillResults memory totalFillResults);
+
+    /// @dev Market sells WETH for ZRX tokens.
+    /// @param orders An array of Order struct containing order specifications.
+    /// @param signatures An array of Proof that order has been created by maker.
+    /// @param wethSellAmount The amount of WETH to sell.
+    /// @return FillResults amounts filled and fees paid by maker and taker.
+    function marketSellEthForZRXInternal(
+        LibOrder.Order[] memory orders,
+        bytes[] memory signatures,
+        uint256 wethSellAmount
+    )
+        internal
+        returns (LibFillResults.FillResults memory totalFillResults);
+
+    /// @dev Buys an exact amount of an ERC20 token using WETH.
+    /// @param orders Orders to fill. The maker asset is the ERC20 token to buy. The taker asset is WETH.
+    /// @param signatures Proof that the orders were created by their respective makers.
+    /// @param feeOrders to fill. The maker asset is ZRX and the taker asset is WETH.
+    /// @param feeSignatures Proof that the feeOrders were created by their respective makers.
+    /// @param makerTokenFillAmount Amount of the ERC20 token to buy.
+    /// @return totalFillResults Aggregated fill results of buying the ERC20 and ZRX tokens.
+    function marketBuyERC20TokensInternal(
+        LibOrder.Order[] memory orders,
+        bytes[] memory signatures,
+        LibOrder.Order[] memory feeOrders,
+        bytes[] memory feeSignatures,
+        uint256 makerTokenFillAmount
+    )
+        internal
+        returns (LibFillResults.FillResults memory totalFillResults);
+
+    /// @dev Buys an all of the ERC721 tokens in the orders.
+    /// @param orders Orders to fill. The maker asset is the ERC721 token to buy. The taker asset is WETH.
+    /// @param signatures Proof that the orders were created by their respective makers.
+    /// @param feeOrders to fill. The maker asset is ZRX and the taker asset is WETH.
+    /// @param feeSignatures Proof that the feeOrders were created by their respective makers.
+    /// @return totalFillResults Aggregated fill results of buying the ERC721 tokens and ZRX tokens.
+    function batchBuyERC721TokensInternal(
+        LibOrder.Order[] memory orders,
+        bytes[] memory signatures,
+        LibOrder.Order[] memory feeOrders,
+        bytes[] memory feeSignatures
+    )
+        internal
+        returns (LibFillResults.FillResults memory totalFillResults);
+}
diff --git a/packages/contracts/src/2.0.0/forwarder/mixins/MMarketBuyZrx.sol b/packages/contracts/src/2.0.0/forwarder/mixins/MMarketBuyZrx.sol
new file mode 100644
index 000000000..3501ef001
--- /dev/null
+++ b/packages/contracts/src/2.0.0/forwarder/mixins/MMarketBuyZrx.sol
@@ -0,0 +1,42 @@
+/*
+
+  Copyright 2018 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity 0.4.24;
+
+import "../../protocol/Exchange/libs/LibFillResults.sol";
+import "../../protocol/Exchange/libs/LibOrder.sol";
+
+
+contract MMarketBuyZrx {
+
+    /// @dev Buys zrxBuyAmount of ZRX fee tokens, taking into account the fees on buying fee tokens. This will guarantee
+    ///      At least zrxBuyAmount of ZRX fee tokens are purchased (sometimes slightly over due to rounding issues).
+    ///      It is possible that a request to buy 200 ZRX fee tokens will require purchasing 202 ZRX tokens
+    ///      As 2 ZRX is required to purchase the 200 ZRX fee tokens. This guarantees at least 200 ZRX for future purchases.
+    /// @param orders An array of Order struct containing order specifications for fees.
+    /// @param signatures An array of Proof that order has been created by maker for the fee orders.
+    /// @param zrxBuyAmount The number of requested ZRX fee tokens.
+    /// @return totalFillResults Amounts filled and fees paid by maker and taker. makerTokenAmount is the zrx amount deducted of fees
+    function marketBuyZrxInternal(
+        LibOrder.Order[] memory orders,
+        bytes[] memory signatures,
+        uint256 zrxBuyAmount
+    )
+        internal
+        returns (LibFillResults.FillResults memory totalFillResults);
+}
diff --git a/packages/contracts/src/2.0.0/forwarder/mixins/MTransfer.sol b/packages/contracts/src/2.0.0/forwarder/mixins/MTransfer.sol
new file mode 100644
index 000000000..418a6288b
--- /dev/null
+++ b/packages/contracts/src/2.0.0/forwarder/mixins/MTransfer.sol
@@ -0,0 +1,46 @@
+/*
+
+  Copyright 2018 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity 0.4.24;
+
+
+contract MTransfer {
+
+    function onERC721Received(address, uint256, bytes memory)
+        public
+        pure
+        returns(bytes4);
+
+    function onERC721Received(address, address, uint256, bytes memory)
+        public
+        pure
+        returns(bytes4);
+    
+    function transferERC20Token(
+        address token,
+        address to,
+        uint256 amount
+    )
+        internal;
+
+    function transferERC721Token(
+        bytes memory assetData,
+        address to
+    )
+        internal;
+}
diff --git a/packages/contracts/src/2.0.0/multisig/MultiSigWallet.sol b/packages/contracts/src/2.0.0/multisig/MultiSigWallet.sol
index 1ceecd907..eb54fe047 100644
--- a/packages/contracts/src/2.0.0/multisig/MultiSigWallet.sol
+++ b/packages/contracts/src/2.0.0/multisig/MultiSigWallet.sol
@@ -1,6 +1,6 @@
+// solhint-disable
 pragma solidity ^0.4.10;
 
-// solhint-disable
 
 /// @title Multisignature wallet - Allows multiple parties to agree on transactions before execution.
 /// @author Stefan George - <stefan.george@consensys.net>
diff --git a/packages/contracts/src/2.0.0/multisig/MultiSigWalletWithTimeLock.sol b/packages/contracts/src/2.0.0/multisig/MultiSigWalletWithTimeLock.sol
index d714b661d..8c5e6e1e6 100644
--- a/packages/contracts/src/2.0.0/multisig/MultiSigWalletWithTimeLock.sol
+++ b/packages/contracts/src/2.0.0/multisig/MultiSigWalletWithTimeLock.sol
@@ -16,11 +16,11 @@
 
 */
 
+// solhint-disable
 pragma solidity ^0.4.10;
 
 import "./MultiSigWallet.sol";
 
-// solhint-disable
 
 /// @title Multisignature wallet with time lock- Allows multiple parties to execute a transaction after a time lock has passed.
 /// @author Amir Bandeali - <amir@0xProject.com>
diff --git a/packages/contracts/src/2.0.0/protocol/AssetProxy/ERC20Proxy.sol b/packages/contracts/src/2.0.0/protocol/AssetProxy/ERC20Proxy.sol
index aed62f54f..b5cec6b64 100644
--- a/packages/contracts/src/2.0.0/protocol/AssetProxy/ERC20Proxy.sol
+++ b/packages/contracts/src/2.0.0/protocol/AssetProxy/ERC20Proxy.sol
@@ -16,18 +16,19 @@
 
 */
 
-pragma solidity ^0.4.24;
-pragma experimental ABIEncoderV2;
+pragma solidity 0.4.24;
 
 import "../../utils/LibBytes/LibBytes.sol";
 import "./MixinAuthorizable.sol";
 
+
 contract ERC20Proxy is
     MixinAuthorizable
 {
     // Id of this proxy.
-    bytes4 constant PROXY_ID = bytes4(keccak256("ERC20Token(address)"));
+    bytes4 constant internal PROXY_ID = bytes4(keccak256("ERC20Token(address)"));
     
+    // solhint-disable-next-line payable-fallback
     function () 
         external
     {
diff --git a/packages/contracts/src/2.0.0/protocol/AssetProxy/ERC721Proxy.sol b/packages/contracts/src/2.0.0/protocol/AssetProxy/ERC721Proxy.sol
index b73dc36cc..1f9958b43 100644
--- a/packages/contracts/src/2.0.0/protocol/AssetProxy/ERC721Proxy.sol
+++ b/packages/contracts/src/2.0.0/protocol/AssetProxy/ERC721Proxy.sol
@@ -16,18 +16,19 @@
 
 */
 
-pragma solidity ^0.4.24;
-pragma experimental ABIEncoderV2;
+pragma solidity 0.4.24;
 
 import "../../utils/LibBytes/LibBytes.sol";
 import "./MixinAuthorizable.sol";
 
+
 contract ERC721Proxy is
     MixinAuthorizable
 {
     // Id of this proxy.
-    bytes4 constant PROXY_ID = bytes4(keccak256("ERC721Token(address,uint256,bytes)"));
+    bytes4 constant internal PROXY_ID = bytes4(keccak256("ERC721Token(address,uint256,bytes)"));
 
+    // solhint-disable-next-line payable-fallback
     function () 
         external
     {
diff --git a/packages/contracts/src/2.0.0/protocol/AssetProxy/MixinAuthorizable.sol b/packages/contracts/src/2.0.0/protocol/AssetProxy/MixinAuthorizable.sol
index 5bc5f3a47..ff4660a31 100644
--- a/packages/contracts/src/2.0.0/protocol/AssetProxy/MixinAuthorizable.sol
+++ b/packages/contracts/src/2.0.0/protocol/AssetProxy/MixinAuthorizable.sol
@@ -16,8 +16,7 @@
 
 */
 
-pragma solidity ^0.4.24;
-pragma experimental ABIEncoderV2;
+pragma solidity 0.4.24;
 
 import "../../utils/Ownable/Ownable.sol";
 import "./mixins/MAuthorizable.sol";
diff --git a/packages/contracts/src/2.0.0/protocol/AssetProxy/interfaces/IAssetData.sol b/packages/contracts/src/2.0.0/protocol/AssetProxy/interfaces/IAssetData.sol
index b4ff2d900..3e76e38dd 100644
--- a/packages/contracts/src/2.0.0/protocol/AssetProxy/interfaces/IAssetData.sol
+++ b/packages/contracts/src/2.0.0/protocol/AssetProxy/interfaces/IAssetData.sol
@@ -16,7 +16,8 @@
 
 */
 
-pragma solidity ^0.4.23;
+// solhint-disable
+pragma solidity 0.4.24;
 
 
 // @dev Interface of the asset proxy's assetData.
@@ -24,12 +25,10 @@ pragma solidity ^0.4.23;
 // This argument is ABI encoded as one of the methods of this interface.
 interface IAssetData {
 
-    // solhint-disable-next-line func-name-mixedcase
     function ERC20Token(address tokenContract)
         external
         pure;
     
-    // solhint-disable-next-line func-name-mixedcase
     function ERC721Token(
         address tokenContract,
         uint256 tokenId,
diff --git a/packages/contracts/src/2.0.0/protocol/AssetProxy/interfaces/IAssetProxy.sol b/packages/contracts/src/2.0.0/protocol/AssetProxy/interfaces/IAssetProxy.sol
index 0ef1ed2e0..3651dd694 100644
--- a/packages/contracts/src/2.0.0/protocol/AssetProxy/interfaces/IAssetProxy.sol
+++ b/packages/contracts/src/2.0.0/protocol/AssetProxy/interfaces/IAssetProxy.sol
@@ -16,8 +16,7 @@
 
 */
 
-pragma solidity ^0.4.24;
-pragma experimental ABIEncoderV2;
+pragma solidity 0.4.24;
 
 import "./IAuthorizable.sol";
 
diff --git a/packages/contracts/src/2.0.0/protocol/AssetProxy/interfaces/IAuthorizable.sol b/packages/contracts/src/2.0.0/protocol/AssetProxy/interfaces/IAuthorizable.sol
index 286db74aa..8fac43a47 100644
--- a/packages/contracts/src/2.0.0/protocol/AssetProxy/interfaces/IAuthorizable.sol
+++ b/packages/contracts/src/2.0.0/protocol/AssetProxy/interfaces/IAuthorizable.sol
@@ -16,8 +16,7 @@
 
 */
 
-pragma solidity ^0.4.24;
-pragma experimental ABIEncoderV2;
+pragma solidity 0.4.24;
 
 import "../../../utils/Ownable/IOwnable.sol";
 
@@ -26,13 +25,6 @@ contract IAuthorizable is
     IOwnable
 {
 
-    /// @dev Gets all authorized addresses.
-    /// @return Array of authorized addresses.
-    function getAuthorizedAddresses()
-        external
-        view
-        returns (address[]);
-
     /// @dev Authorizes an address.
     /// @param target Address to authorize.
     function addAuthorizedAddress(address target)
@@ -51,4 +43,11 @@ contract IAuthorizable is
         uint256 index
     )
         external;
+    
+    /// @dev Gets all authorized addresses.
+    /// @return Array of authorized addresses.
+    function getAuthorizedAddresses()
+        external
+        view
+        returns (address[] memory);
 }
diff --git a/packages/contracts/src/2.0.0/protocol/AssetProxy/libs/LibAssetProxyErrors.sol b/packages/contracts/src/2.0.0/protocol/AssetProxy/libs/LibAssetProxyErrors.sol
index 4b460ea9a..1d9a70cc1 100644
--- a/packages/contracts/src/2.0.0/protocol/AssetProxy/libs/LibAssetProxyErrors.sol
+++ b/packages/contracts/src/2.0.0/protocol/AssetProxy/libs/LibAssetProxyErrors.sol
@@ -16,7 +16,8 @@
 
 */
 
-pragma solidity ^0.4.24;
+// solhint-disable
+pragma solidity 0.4.24;
 
 
 /// @dev This contract documents the revert reasons used in the AssetProxy contracts.
diff --git a/packages/contracts/src/2.0.0/protocol/AssetProxy/mixins/MAuthorizable.sol b/packages/contracts/src/2.0.0/protocol/AssetProxy/mixins/MAuthorizable.sol
index 66c259a23..8afc8c8d8 100644
--- a/packages/contracts/src/2.0.0/protocol/AssetProxy/mixins/MAuthorizable.sol
+++ b/packages/contracts/src/2.0.0/protocol/AssetProxy/mixins/MAuthorizable.sol
@@ -16,8 +16,7 @@
 
 */
 
-pragma solidity ^0.4.24;
-pragma experimental ABIEncoderV2;
+pragma solidity 0.4.24;
 
 import "../interfaces/IAuthorizable.sol";
 
diff --git a/packages/contracts/src/2.0.0/protocol/AssetProxyOwner/AssetProxyOwner.sol b/packages/contracts/src/2.0.0/protocol/AssetProxyOwner/AssetProxyOwner.sol
index 232155a6b..e7cf4ab5c 100644
--- a/packages/contracts/src/2.0.0/protocol/AssetProxyOwner/AssetProxyOwner.sol
+++ b/packages/contracts/src/2.0.0/protocol/AssetProxyOwner/AssetProxyOwner.sol
@@ -33,7 +33,7 @@ contract AssetProxyOwner is
     // if this contract is allowed to call the AssetProxy's `removeAuthorizedAddressAtIndex` method without a time lock.
     mapping (address => bool) public isAssetProxyRegistered;
 
-    bytes4 constant REMOVE_AUTHORIZED_ADDRESS_AT_INDEX_SELECTOR = bytes4(keccak256("removeAuthorizedAddressAtIndex(address,uint256)"));
+    bytes4 constant internal REMOVE_AUTHORIZED_ADDRESS_AT_INDEX_SELECTOR = bytes4(keccak256("removeAuthorizedAddressAtIndex(address,uint256)"));
 
     /// @dev Function will revert if the transaction does not call `removeAuthorizedAddressAtIndex`
     ///      on an approved AssetProxy contract.
@@ -89,6 +89,7 @@ contract AssetProxyOwner is
     {
         Transaction storage tx = transactions[transactionId];
         tx.executed = true;
+        // solhint-disable-next-line avoid-call-value
         if (tx.destination.call.value(tx.value)(tx.data))
             Execution(transactionId);
         else {
diff --git a/packages/contracts/src/2.0.0/protocol/Exchange/Exchange.sol b/packages/contracts/src/2.0.0/protocol/Exchange/Exchange.sol
index effff82e0..7507d3da1 100644
--- a/packages/contracts/src/2.0.0/protocol/Exchange/Exchange.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/Exchange.sol
@@ -16,7 +16,7 @@
 
 */
 
-pragma solidity ^0.4.24;
+pragma solidity 0.4.24;
 pragma experimental ABIEncoderV2;
 
 import "./libs/LibConstants.sol";
@@ -28,6 +28,7 @@ import "./MixinTransactions.sol";
 import "./MixinMatchOrders.sol";
 
 
+// solhint-disable no-empty-blocks
 contract Exchange is
     MixinExchangeCore,
     MixinMatchOrders,
diff --git a/packages/contracts/src/2.0.0/protocol/Exchange/MixinAssetProxyDispatcher.sol b/packages/contracts/src/2.0.0/protocol/Exchange/MixinAssetProxyDispatcher.sol
index dcfe9e1de..e9f882194 100644
--- a/packages/contracts/src/2.0.0/protocol/Exchange/MixinAssetProxyDispatcher.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/MixinAssetProxyDispatcher.sol
@@ -16,7 +16,7 @@
 
 */
 
-pragma solidity ^0.4.24;
+pragma solidity 0.4.24;
 
 import "../../utils/Ownable/Ownable.sol";
 import "../../utils/LibBytes/LibBytes.sol";
@@ -151,6 +151,7 @@ contract MixinAssetProxyDispatcher is
                 /////// Setup Data Area ///////
                 // This area holds `assetData`.
                 let dataArea := add(cdStart, 132)
+                // solhint-disable-next-line no-empty-blocks
                 for {} lt(dataArea, cdEnd) {} {
                     mstore(dataArea, mload(assetData))
                     dataArea := add(dataArea, 32)
diff --git a/packages/contracts/src/2.0.0/protocol/Exchange/MixinExchangeCore.sol b/packages/contracts/src/2.0.0/protocol/Exchange/MixinExchangeCore.sol
index 9e63dc1c0..ec84b1e19 100644
--- a/packages/contracts/src/2.0.0/protocol/Exchange/MixinExchangeCore.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/MixinExchangeCore.sol
@@ -16,7 +16,7 @@
 
 */
 
-pragma solidity ^0.4.24;
+pragma solidity 0.4.24;
 pragma experimental ABIEncoderV2;
 
 import "./libs/LibConstants.sol";
@@ -49,8 +49,6 @@ contract MixinExchangeCore is
     // Orders with specified senderAddress and with a salt less than their epoch to are considered cancelled
     mapping (address => mapping (address => uint256)) public orderEpoch;
 
-    ////// Core exchange functions //////
-
     /// @dev Cancels all orders created by makerAddress with a salt less than or equal to the targetOrderEpoch
     ///      and senderAddress equal to msg.sender (or null address if msg.sender == makerAddress).
     /// @param targetOrderEpoch Orders created with a salt less or equal to this value will be cancelled.
@@ -175,6 +173,7 @@ contract MixinExchangeCore is
         }
 
         // Validate order expiration
+        // solhint-disable-next-line not-rely-on-time
         if (block.timestamp >= order.expirationTimeSeconds) {
             orderInfo.orderStatus = uint8(OrderStatus.EXPIRED);
             return orderInfo;
@@ -375,21 +374,19 @@ contract MixinExchangeCore is
         returns (FillResults memory fillResults)
     {
         // Compute proportional transfer amounts
-        // TODO: All three are multiplied by the same fraction. This can
-        // potentially be optimized.
         fillResults.takerAssetFilledAmount = takerAssetFilledAmount;
         fillResults.makerAssetFilledAmount = getPartialAmount(
-            fillResults.takerAssetFilledAmount,
+            takerAssetFilledAmount,
             order.takerAssetAmount,
             order.makerAssetAmount
         );
         fillResults.makerFeePaid = getPartialAmount(
-            fillResults.takerAssetFilledAmount,
+            takerAssetFilledAmount,
             order.takerAssetAmount,
             order.makerFee
         );
         fillResults.takerFeePaid = getPartialAmount(
-            fillResults.takerAssetFilledAmount,
+            takerAssetFilledAmount,
             order.takerAssetAmount,
             order.takerFee
         );
diff --git a/packages/contracts/src/2.0.0/protocol/Exchange/MixinMatchOrders.sol b/packages/contracts/src/2.0.0/protocol/Exchange/MixinMatchOrders.sol
index bfe838837..56b309a1b 100644
--- a/packages/contracts/src/2.0.0/protocol/Exchange/MixinMatchOrders.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/MixinMatchOrders.sol
@@ -11,7 +11,7 @@
   limitations under the License.
 */
 
-pragma solidity ^0.4.24;
+pragma solidity 0.4.24;
 pragma experimental ABIEncoderV2;
 
 import "./libs/LibConstants.sol";
@@ -41,7 +41,6 @@ contract MixinMatchOrders is
     /// @param leftSignature Proof that order was created by the left maker.
     /// @param rightSignature Proof that order was created by the right maker.
     /// @return matchedFillResults Amounts filled and fees paid by maker and taker of matched orders.
-    /// TODO: Make this function external once supported by Solidity (See Solidity Issues #3199, #1603)
     function matchOrders(
         LibOrder.Order memory leftOrder,
         LibOrder.Order memory rightOrder,
@@ -184,7 +183,6 @@ contract MixinMatchOrders is
             leftTakerAssetFilledAmount = leftTakerAssetAmountRemaining;
 
             // The right order receives an amount proportional to how much was spent.
-            // TODO: Can we ensure rounding error is in the correct direction?
             rightTakerAssetFilledAmount = getPartialAmount(
                 rightOrder.takerAssetAmount,
                 rightOrder.makerAssetAmount,
@@ -195,7 +193,6 @@ contract MixinMatchOrders is
             rightTakerAssetFilledAmount = rightTakerAssetAmountRemaining;
 
             // The left order receives an amount proportional to how much was spent.
-            // TODO: Can we ensure rounding error is in the correct direction?
             leftTakerAssetFilledAmount = getPartialAmount(
                 rightOrder.makerAssetAmount,
                 rightOrder.takerAssetAmount,
diff --git a/packages/contracts/src/2.0.0/protocol/Exchange/MixinSignatureValidator.sol b/packages/contracts/src/2.0.0/protocol/Exchange/MixinSignatureValidator.sol
index 78f13286f..ac7382715 100644
--- a/packages/contracts/src/2.0.0/protocol/Exchange/MixinSignatureValidator.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/MixinSignatureValidator.sol
@@ -16,7 +16,7 @@
 
 */
 
-pragma solidity ^0.4.24;
+pragma solidity 0.4.24;
 
 import "../../utils/LibBytes/LibBytes.sol";
 import "./mixins/MSignatureValidator.sol";
@@ -91,7 +91,6 @@ contract MixinSignatureValidator is
         view
         returns (bool isValid)
     {
-        // TODO: Domain separation: make hash depend on role. (Taker sig should not be valid as maker sig, etc.)
         require(
             signature.length > 0,
             "LENGTH_GREATER_THAN_0_REQUIRED"
diff --git a/packages/contracts/src/2.0.0/protocol/Exchange/MixinTransactions.sol b/packages/contracts/src/2.0.0/protocol/Exchange/MixinTransactions.sol
index 3b18ac733..88d2da7d7 100644
--- a/packages/contracts/src/2.0.0/protocol/Exchange/MixinTransactions.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/MixinTransactions.sol
@@ -15,7 +15,7 @@
   limitations under the License.
 
 */
-pragma solidity ^0.4.24;
+pragma solidity 0.4.24;
 
 import "./libs/LibExchangeErrors.sol";
 import "./mixins/MSignatureValidator.sol";
@@ -37,7 +37,7 @@ contract MixinTransactions is
     address public currentContextAddress;
 
     // Hash for the EIP712 ZeroEx Transaction Schema
-    bytes32 constant EIP712_ZEROEX_TRANSACTION_SCHEMA_HASH = keccak256(abi.encodePacked(
+    bytes32 constant internal EIP712_ZEROEX_TRANSACTION_SCHEMA_HASH = keccak256(abi.encodePacked(
         "ZeroExTransaction(",
         "uint256 salt,",
         "address signerAddress,",
@@ -45,41 +45,6 @@ contract MixinTransactions is
         ")"
     ));
 
-    /// @dev Calculates EIP712 hash of the Transaction.
-    /// @param salt Arbitrary number to ensure uniqueness of transaction hash.
-    /// @param signerAddress Address of transaction signer.
-    /// @param data AbiV2 encoded calldata.
-    /// @return EIP712 hash of the Transaction.
-    function hashZeroExTransaction(
-        uint256 salt,
-        address signerAddress,
-        bytes memory data
-    )
-        internal
-        pure
-        returns (bytes32 result)
-    {
-        bytes32 schemaHash = EIP712_ZEROEX_TRANSACTION_SCHEMA_HASH;
-        bytes32 dataHash = keccak256(data);
-        // Assembly for more efficiently computing:
-        // keccak256(abi.encode(
-        //   EIP712_ZEROEX_TRANSACTION_SCHEMA_HASH,
-        //   salt,
-        //   signerAddress,
-        //   keccak256(data)
-        //  ));
-        assembly {
-            let memPtr := mload(64)
-            mstore(memPtr, schemaHash)
-            mstore(add(memPtr, 32), salt)
-            mstore(add(memPtr, 64), and(signerAddress, 0xffffffffffffffffffffffffffffffffffffffff))
-            mstore(add(memPtr, 96), dataHash)
-            result := keccak256(memPtr, 128)
-        }
-
-        return result;
-    }
-
     /// @dev Executes an exchange method call in the context of signer.
     /// @param salt Arbitrary number to ensure uniqueness of transaction hash.
     /// @param signerAddress Address of transaction signer.
@@ -134,9 +99,47 @@ contract MixinTransactions is
             "FAILED_EXECUTION"
         );
 
-        // Reset current transaction signer
-        // TODO: Check if gas is paid when currentContextAddress is already 0.
-        currentContextAddress = address(0);
+        // Reset current transaction signer if it was previously updated
+        if (signerAddress != msg.sender) {
+            currentContextAddress = address(0);
+        }
+    }
+
+    /// @dev Calculates EIP712 hash of the Transaction.
+    /// @param salt Arbitrary number to ensure uniqueness of transaction hash.
+    /// @param signerAddress Address of transaction signer.
+    /// @param data AbiV2 encoded calldata.
+    /// @return EIP712 hash of the Transaction.
+    function hashZeroExTransaction(
+        uint256 salt,
+        address signerAddress,
+        bytes memory data
+    )
+        internal
+        pure
+        returns (bytes32 result)
+    {
+        bytes32 schemaHash = EIP712_ZEROEX_TRANSACTION_SCHEMA_HASH;
+        bytes32 dataHash = keccak256(data);
+
+        // Assembly for more efficiently computing:
+        // keccak256(abi.encode(
+        //     EIP712_ZEROEX_TRANSACTION_SCHEMA_HASH,
+        //     salt,
+        //     signerAddress,
+        //     keccak256(data)
+        // ));
+
+        assembly {
+            let memPtr := mload(64)
+            mstore(memPtr, schemaHash)
+            mstore(add(memPtr, 32), salt)
+            mstore(add(memPtr, 64), and(signerAddress, 0xffffffffffffffffffffffffffffffffffffffff))
+            mstore(add(memPtr, 96), dataHash)
+            result := keccak256(memPtr, 128)
+        }
+
+        return result;
     }
 
     /// @dev The current function will be called in the context of this address (either 0x transaction signer or `msg.sender`).
diff --git a/packages/contracts/src/2.0.0/protocol/Exchange/MixinWrapperFunctions.sol b/packages/contracts/src/2.0.0/protocol/Exchange/MixinWrapperFunctions.sol
index 678d0252a..a16d2f897 100644
--- a/packages/contracts/src/2.0.0/protocol/Exchange/MixinWrapperFunctions.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/MixinWrapperFunctions.sol
@@ -16,7 +16,7 @@
 
 */
 
-pragma solidity ^0.4.24;
+pragma solidity 0.4.24;
 pragma experimental ABIEncoderV2;
 
 import "./libs/LibMath.sol";
diff --git a/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IAssetProxyDispatcher.sol b/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IAssetProxyDispatcher.sol
index b73881c07..8db8d6f6c 100644
--- a/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IAssetProxyDispatcher.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IAssetProxyDispatcher.sol
@@ -16,7 +16,7 @@
 
 */
 
-pragma solidity ^0.4.24;
+pragma solidity 0.4.24;
 
 
 contract IAssetProxyDispatcher {
diff --git a/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IExchange.sol b/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IExchange.sol
index 05e5dedf4..b92abba04 100644
--- a/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IExchange.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IExchange.sol
@@ -16,7 +16,7 @@
 
 */
 
-pragma solidity ^0.4.24;
+pragma solidity 0.4.24;
 pragma experimental ABIEncoderV2;
 
 import "./IExchangeCore.sol";
@@ -27,6 +27,7 @@ import "./IAssetProxyDispatcher.sol";
 import "./IWrapperFunctions.sol";
 
 
+// solhint-disable no-empty-blocks
 contract IExchange is
     IExchangeCore,
     IMatchOrders,
diff --git a/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IExchangeCore.sol b/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IExchangeCore.sol
index 2b573eb1a..9995e0385 100644
--- a/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IExchangeCore.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IExchangeCore.sol
@@ -16,7 +16,7 @@
 
 */
 
-pragma solidity ^0.4.24;
+pragma solidity 0.4.24;
 pragma experimental ABIEncoderV2;
 
 import "../libs/LibOrder.sol";
diff --git a/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IMatchOrders.sol b/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IMatchOrders.sol
index d44116474..73447f3ae 100644
--- a/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IMatchOrders.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IMatchOrders.sol
@@ -15,7 +15,7 @@
   limitations under the License.
 
 */
-pragma solidity ^0.4.24;
+pragma solidity 0.4.24;
 pragma experimental ABIEncoderV2;
 
 import "../libs/LibOrder.sol";
@@ -33,7 +33,6 @@ contract IMatchOrders {
     /// @param leftSignature Proof that order was created by the left maker.
     /// @param rightSignature Proof that order was created by the right maker.
     /// @return matchedFillResults Amounts filled and fees paid by maker and taker of matched orders.
-    /// TODO: Make this function external once supported by Solidity (See Solidity Issues #3199, #1603)
     function matchOrders(
         LibOrder.Order memory leftOrder,
         LibOrder.Order memory rightOrder,
diff --git a/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/ISignatureValidator.sol b/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/ISignatureValidator.sol
index c5a4a57e1..1fd0eccf0 100644
--- a/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/ISignatureValidator.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/ISignatureValidator.sol
@@ -16,7 +16,7 @@
 
 */
 
-pragma solidity ^0.4.24;
+pragma solidity 0.4.24;
 
 
 contract ISignatureValidator {
diff --git a/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/ITransactions.sol b/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/ITransactions.sol
index aaaee389f..4446c55ce 100644
--- a/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/ITransactions.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/ITransactions.sol
@@ -15,7 +15,7 @@
   limitations under the License.
 
 */
-pragma solidity ^0.4.24;
+pragma solidity 0.4.24;
 
 
 contract ITransactions {
diff --git a/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IValidator.sol b/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IValidator.sol
index 2c0a5dbe2..2dd69100c 100644
--- a/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IValidator.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IValidator.sol
@@ -16,7 +16,7 @@
 
 */
 
-pragma solidity ^0.4.23;
+pragma solidity 0.4.24;
 
 
 contract IValidator {
diff --git a/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IWallet.sol b/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IWallet.sol
index c2db4a5b1..c97161ca6 100644
--- a/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IWallet.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IWallet.sol
@@ -16,7 +16,7 @@
 
 */
 
-pragma solidity ^0.4.24;
+pragma solidity 0.4.24;
 
 
 contract IWallet {
diff --git a/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IWrapperFunctions.sol b/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IWrapperFunctions.sol
index 04257b883..ad7a56a06 100644
--- a/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IWrapperFunctions.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IWrapperFunctions.sol
@@ -16,7 +16,7 @@
 
 */
 
-pragma solidity ^0.4.24;
+pragma solidity 0.4.24;
 pragma experimental ABIEncoderV2;
 
 import "../libs/LibOrder.sol";
@@ -24,6 +24,7 @@ import "../libs/LibFillResults.sol";
 
 
 contract IWrapperFunctions {
+
     /// @dev Fills the input order. Reverts if exact takerAssetFillAmount not filled.
     /// @param order LibOrder.Order struct containing order specifications.
     /// @param takerAssetFillAmount Desired amount of takerAsset to sell.
diff --git a/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibConstants.sol b/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibConstants.sol
index 76200ec44..6918d755e 100644
--- a/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibConstants.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibConstants.sol
@@ -16,7 +16,7 @@
 
 */
 
-pragma solidity ^0.4.24;
+pragma solidity 0.4.24;
 
 
 contract LibConstants {
diff --git a/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibEIP712.sol b/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibEIP712.sol
index 2bd7b60d4..1fc41dafd 100644
--- a/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibEIP712.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibEIP712.sol
@@ -16,18 +16,18 @@
 
 */
 
-pragma solidity ^0.4.24;
+pragma solidity 0.4.24;
 
 
 contract LibEIP712 {
     // EIP191 header for EIP712 prefix
-    string constant EIP191_HEADER = "\x19\x01";
+    string constant internal EIP191_HEADER = "\x19\x01";
 
     // EIP712 Domain Name value
-    string constant EIP712_DOMAIN_NAME = "0x Protocol";
+    string constant internal EIP712_DOMAIN_NAME = "0x Protocol";
 
     // EIP712 Domain Version value
-    string constant EIP712_DOMAIN_VERSION = "2";
+    string constant internal EIP712_DOMAIN_VERSION = "2";
 
     // Hash of the EIP712 Domain Separator Schema
     bytes32 public constant EIP712_DOMAIN_SEPARATOR_SCHEMA_HASH = keccak256(abi.encodePacked(
diff --git a/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibExchangeErrors.sol b/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibExchangeErrors.sol
index 99f683e1a..a0f75bc06 100644
--- a/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibExchangeErrors.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibExchangeErrors.sol
@@ -16,7 +16,8 @@
 
 */
 
-pragma solidity ^0.4.24;
+// solhint-disable
+pragma solidity 0.4.24;
 
 
 /// @dev This contract documents the revert reasons used in the Exchange contract.
diff --git a/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibFillResults.sol b/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibFillResults.sol
index 35fa9ac0f..1b4181d94 100644
--- a/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibFillResults.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibFillResults.sol
@@ -16,7 +16,7 @@
 
 */
 
-pragma solidity ^0.4.24;
+pragma solidity 0.4.24;
 
 import "../../../utils/SafeMath/SafeMath.sol";
 
diff --git a/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibMath.sol b/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibMath.sol
index 9da784854..46c13d390 100644
--- a/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibMath.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibMath.sol
@@ -16,7 +16,7 @@
 
 */
 
-pragma solidity ^0.4.24;
+pragma solidity 0.4.24;
 
 import "../../../utils/SafeMath/SafeMath.sol";
 
diff --git a/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibOrder.sol b/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibOrder.sol
index dda581d9f..68f2c8aed 100644
--- a/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibOrder.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibOrder.sol
@@ -16,7 +16,7 @@
 
 */
 
-pragma solidity ^0.4.24;
+pragma solidity 0.4.24;
 
 import "./LibEIP712.sol";
 
@@ -26,7 +26,7 @@ contract LibOrder is
 {
 
     // Hash for the EIP712 Order Schema
-    bytes32 constant EIP712_ORDER_SCHEMA_HASH = keccak256(abi.encodePacked(
+    bytes32 constant internal EIP712_ORDER_SCHEMA_HASH = keccak256(abi.encodePacked(
         "Order(",
         "address makerAddress,",
         "address takerAddress,",
@@ -55,6 +55,7 @@ contract LibOrder is
         CANCELLED                    // Order has been cancelled
     }
 
+    // solhint-disable max-line-length
     struct Order {
         address makerAddress;           // Address that created the order.      
         address takerAddress;           // Address that is allowed to fill the order. If set to 0, any address is allowed to fill the order.          
@@ -69,6 +70,7 @@ contract LibOrder is
         bytes makerAssetData;           // Encoded data that can be decoded by a specified proxy contract when transferring makerAsset. The last byte references the id of this proxy.
         bytes takerAssetData;           // Encoded data that can be decoded by a specified proxy contract when transferring takerAsset. The last byte references the id of this proxy.
     }
+    // solhint-enable max-line-length
 
     struct OrderInfo {
         uint8 orderStatus;                    // Status that describes order's validity and fillability.
@@ -99,21 +101,23 @@ contract LibOrder is
         bytes32 schemaHash = EIP712_ORDER_SCHEMA_HASH;
         bytes32 makerAssetDataHash = keccak256(order.makerAssetData);
         bytes32 takerAssetDataHash = keccak256(order.takerAssetData);
+
         // Assembly for more efficiently computing:
-        //   keccak256(abi.encode(
-        //       order.makerAddress,
-        //       order.takerAddress,
-        //       order.feeRecipientAddress,
-        //       order.senderAddress,
-        //       order.makerAssetAmount,
-        //       order.takerAssetAmount,
-        //       order.makerFee,
-        //       order.takerFee,
-        //       order.expirationTimeSeconds,
-        //       order.salt,
-        //       keccak256(order.makerAssetData),
-        //       keccak256(order.takerAssetData)
-        //   ));
+        //    keccak256(abi.encode(
+        //        order.makerAddress,
+        //        order.takerAddress,
+        //        order.feeRecipientAddress,
+        //        order.senderAddress,
+        //        order.makerAssetAmount,
+        //        order.takerAssetAmount,
+        //        order.makerFee,
+        //        order.takerFee,
+        //        order.expirationTimeSeconds,
+        //        order.salt,
+        //        keccak256(order.makerAssetData),
+        //        keccak256(order.takerAssetData)
+        //    ));
+
         assembly {
             // Backup
             // solhint-disable-next-line space-after-comma
diff --git a/packages/contracts/src/2.0.0/protocol/Exchange/mixins/MAssetProxyDispatcher.sol b/packages/contracts/src/2.0.0/protocol/Exchange/mixins/MAssetProxyDispatcher.sol
index 367b37e80..c6904300a 100644
--- a/packages/contracts/src/2.0.0/protocol/Exchange/mixins/MAssetProxyDispatcher.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/mixins/MAssetProxyDispatcher.sol
@@ -16,8 +16,7 @@
 
 */
 
-pragma solidity ^0.4.24;
-pragma experimental ABIEncoderV2;
+pragma solidity 0.4.24;
 
 import "../interfaces/IAssetProxyDispatcher.sol";
 
diff --git a/packages/contracts/src/2.0.0/protocol/Exchange/mixins/MExchangeCore.sol b/packages/contracts/src/2.0.0/protocol/Exchange/mixins/MExchangeCore.sol
index e28d9d25b..9e3b5a2e2 100644
--- a/packages/contracts/src/2.0.0/protocol/Exchange/mixins/MExchangeCore.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/mixins/MExchangeCore.sol
@@ -16,7 +16,7 @@
 
 */
 
-pragma solidity ^0.4.24;
+pragma solidity 0.4.24;
 pragma experimental ABIEncoderV2;
 
 import "../libs/LibOrder.sol";
@@ -102,7 +102,6 @@ contract MExchangeCore is
         internal
         view;
 
-
     /// @dev Validates context for cancelOrder. Succeeds or throws.
     /// @param order to be cancelled.
     /// @param orderInfo OrderStatus, orderHash, and amount already filled of order.
diff --git a/packages/contracts/src/2.0.0/protocol/Exchange/mixins/MMatchOrders.sol b/packages/contracts/src/2.0.0/protocol/Exchange/mixins/MMatchOrders.sol
index 289514b24..a31ec1585 100644
--- a/packages/contracts/src/2.0.0/protocol/Exchange/mixins/MMatchOrders.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/mixins/MMatchOrders.sol
@@ -15,7 +15,7 @@
   limitations under the License.
 
 */
-pragma solidity ^0.4.24;
+pragma solidity 0.4.24;
 pragma experimental ABIEncoderV2;
 
 import "../libs/LibOrder.sol";
diff --git a/packages/contracts/src/2.0.0/protocol/Exchange/mixins/MSignatureValidator.sol b/packages/contracts/src/2.0.0/protocol/Exchange/mixins/MSignatureValidator.sol
index 83650b4aa..f14f2ba00 100644
--- a/packages/contracts/src/2.0.0/protocol/Exchange/mixins/MSignatureValidator.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/mixins/MSignatureValidator.sol
@@ -16,7 +16,7 @@
 
 */
 
-pragma solidity ^0.4.24;
+pragma solidity 0.4.24;
 
 import "../interfaces/ISignatureValidator.sol";
 
diff --git a/packages/contracts/src/2.0.0/protocol/Exchange/mixins/MTransactions.sol b/packages/contracts/src/2.0.0/protocol/Exchange/mixins/MTransactions.sol
index a9fa6d4e2..f2b5e4b16 100644
--- a/packages/contracts/src/2.0.0/protocol/Exchange/mixins/MTransactions.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/mixins/MTransactions.sol
@@ -15,7 +15,7 @@
   limitations under the License.
 
 */
-pragma solidity ^0.4.24;
+pragma solidity 0.4.24;
 
 import "../interfaces/ITransactions.sol";
 
diff --git a/packages/contracts/src/2.0.0/test/DummyERC20Token/DummyERC20Token.sol b/packages/contracts/src/2.0.0/test/DummyERC20Token/DummyERC20Token.sol
index 7a2702449..97801166a 100644
--- a/packages/contracts/src/2.0.0/test/DummyERC20Token/DummyERC20Token.sol
+++ b/packages/contracts/src/2.0.0/test/DummyERC20Token/DummyERC20Token.sol
@@ -16,8 +16,7 @@
 
 */
 
-pragma solidity ^0.4.24;
-pragma experimental ABIEncoderV2;
+pragma solidity 0.4.24;
 
 import "../Mintable/Mintable.sol";
 import "../../utils/Ownable/Ownable.sol";
diff --git a/packages/contracts/src/2.0.0/test/DummyERC721Receiver/DummyERC721Receiver.sol b/packages/contracts/src/2.0.0/test/DummyERC721Receiver/DummyERC721Receiver.sol
index b027ac960..5dce74a14 100644
--- a/packages/contracts/src/2.0.0/test/DummyERC721Receiver/DummyERC721Receiver.sol
+++ b/packages/contracts/src/2.0.0/test/DummyERC721Receiver/DummyERC721Receiver.sol
@@ -23,7 +23,7 @@ TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
 
-pragma solidity ^0.4.24;
+pragma solidity 0.4.24;
 
 import "../../tokens/ERC721Token/IERC721Receiver.sol";
 
diff --git a/packages/contracts/src/2.0.0/test/DummyERC721Token/DummyERC721Token.sol b/packages/contracts/src/2.0.0/test/DummyERC721Token/DummyERC721Token.sol
index de76f10c5..627746a52 100644
--- a/packages/contracts/src/2.0.0/test/DummyERC721Token/DummyERC721Token.sol
+++ b/packages/contracts/src/2.0.0/test/DummyERC721Token/DummyERC721Token.sol
@@ -16,13 +16,13 @@
 
 */
 
-pragma solidity ^0.4.24;
-pragma experimental ABIEncoderV2;
+pragma solidity 0.4.24;
 
 import "../../tokens/ERC721Token/ERC721Token.sol";
 import "../../utils/Ownable/Ownable.sol";
 
 
+// solhint-disable no-empty-blocks
 contract DummyERC721Token is
     Ownable,
     ERC721Token
diff --git a/packages/contracts/src/2.0.0/test/ExchangeWrapper/ExchangeWrapper.sol b/packages/contracts/src/2.0.0/test/ExchangeWrapper/ExchangeWrapper.sol
index f20e2a944..2fa0e3c5e 100644
--- a/packages/contracts/src/2.0.0/test/ExchangeWrapper/ExchangeWrapper.sol
+++ b/packages/contracts/src/2.0.0/test/ExchangeWrapper/ExchangeWrapper.sol
@@ -16,7 +16,7 @@
 
 */
 
-pragma solidity ^0.4.24;
+pragma solidity 0.4.24;
 pragma experimental ABIEncoderV2;
 
 import "../../protocol/Exchange/interfaces/IExchange.sol";
@@ -27,7 +27,7 @@ contract ExchangeWrapper {
 
     // Exchange contract.
     // solhint-disable-next-line var-name-mixedcase
-    IExchange EXCHANGE;
+    IExchange internal EXCHANGE;
 
     constructor (address _exchange)
         public
@@ -35,6 +35,35 @@ contract ExchangeWrapper {
         EXCHANGE = IExchange(_exchange);
     }
 
+    /// @dev Cancels all orders created by sender with a salt less than or equal to the targetOrderEpoch
+    ///      and senderAddress equal to this contract.
+    /// @param targetOrderEpoch Orders created with a salt less or equal to this value will be cancelled.
+    /// @param salt Arbitrary value to gaurantee uniqueness of 0x transaction hash.
+    /// @param makerSignature Proof that maker wishes to call this function with given params.
+    function cancelOrdersUpTo(
+        uint256 targetOrderEpoch,
+        uint256 salt,
+        bytes makerSignature
+    )
+        external
+    {
+        address makerAddress = msg.sender;
+
+        // Encode arguments into byte array.
+        bytes memory data = abi.encodeWithSelector(
+            EXCHANGE.cancelOrdersUpTo.selector,
+            targetOrderEpoch
+        );
+
+        // Call `cancelOrdersUpTo` via `executeTransaction`.
+        EXCHANGE.executeTransaction(
+            salt,
+            makerAddress,
+            data,
+            makerSignature
+        );
+    }
+
     /// @dev Fills an order using `msg.sender` as the taker.
     /// @param order Order struct containing order specifications.
     /// @param takerAssetFillAmount Desired amount of takerAsset to sell.
@@ -68,33 +97,4 @@ contract ExchangeWrapper {
             takerSignature
         );
     }
-
-    /// @dev Cancels all orders created by sender with a salt less than or equal to the targetOrderEpoch
-    ///      and senderAddress equal to this contract.
-    /// @param targetOrderEpoch Orders created with a salt less or equal to this value will be cancelled.
-    /// @param salt Arbitrary value to gaurantee uniqueness of 0x transaction hash.
-    /// @param makerSignature Proof that maker wishes to call this function with given params.
-    function cancelOrdersUpTo(
-        uint256 targetOrderEpoch,
-        uint256 salt,
-        bytes makerSignature
-    )
-        external
-    {
-        address makerAddress = msg.sender;
-
-        // Encode arguments into byte array.
-        bytes memory data = abi.encodeWithSelector(
-            EXCHANGE.cancelOrdersUpTo.selector,
-            targetOrderEpoch
-        );
-
-        // Call `cancelOrdersUpTo` via `executeTransaction`.
-        EXCHANGE.executeTransaction(
-            salt,
-            makerAddress,
-            data,
-            makerSignature
-        );
-    }
 }
diff --git a/packages/contracts/src/2.0.0/test/Mintable/Mintable.sol b/packages/contracts/src/2.0.0/test/Mintable/Mintable.sol
index bccb74ce8..767cc8d25 100644
--- a/packages/contracts/src/2.0.0/test/Mintable/Mintable.sol
+++ b/packages/contracts/src/2.0.0/test/Mintable/Mintable.sol
@@ -16,8 +16,7 @@
 
 */
 
-pragma solidity ^0.4.24;
-pragma experimental ABIEncoderV2;
+pragma solidity 0.4.24;
 
 import "../../tokens/UnlimitedAllowanceToken/UnlimitedAllowanceToken.sol";
 import "../../utils/SafeMath/SafeMath.sol";
@@ -27,7 +26,10 @@ import "../../utils/SafeMath/SafeMath.sol";
  * Mintable
  * Base contract that creates a mintable UnlimitedAllowanceToken
  */
-contract Mintable is UnlimitedAllowanceToken, SafeMath {
+contract Mintable is 
+    UnlimitedAllowanceToken,
+    SafeMath
+{
     function mint(uint256 _value)
         public
     {
diff --git a/packages/contracts/src/2.0.0/test/TestAssetProxyDispatcher/TestAssetProxyDispatcher.sol b/packages/contracts/src/2.0.0/test/TestAssetProxyDispatcher/TestAssetProxyDispatcher.sol
index be7fea7d3..07986f4bb 100644
--- a/packages/contracts/src/2.0.0/test/TestAssetProxyDispatcher/TestAssetProxyDispatcher.sol
+++ b/packages/contracts/src/2.0.0/test/TestAssetProxyDispatcher/TestAssetProxyDispatcher.sol
@@ -16,8 +16,7 @@
 
 */
 
-pragma solidity ^0.4.24;
-pragma experimental ABIEncoderV2;
+pragma solidity 0.4.24;
 
 import "../../protocol/Exchange/MixinAssetProxyDispatcher.sol";
 
@@ -27,7 +26,8 @@ contract TestAssetProxyDispatcher is MixinAssetProxyDispatcher {
         bytes memory assetData,
         address from,
         address to,
-        uint256 amount)
+        uint256 amount
+    )
         public
     {
         dispatchTransferFrom(assetData, from, to, amount);
diff --git a/packages/contracts/src/2.0.0/test/TestAssetProxyOwner/TestAssetProxyOwner.sol b/packages/contracts/src/2.0.0/test/TestAssetProxyOwner/TestAssetProxyOwner.sol
index ddcc62f35..d6b6b29f2 100644
--- a/packages/contracts/src/2.0.0/test/TestAssetProxyOwner/TestAssetProxyOwner.sol
+++ b/packages/contracts/src/2.0.0/test/TestAssetProxyOwner/TestAssetProxyOwner.sol
@@ -16,14 +16,16 @@
 
 */
 
-pragma solidity ^0.4.24;
+pragma solidity 0.4.24;
 
 import "../../protocol/AssetProxyOwner/AssetProxyOwner.sol";
 
 
+// solhint-disable no-empty-blocks
 contract TestAssetProxyOwner is
     AssetProxyOwner
 {
+
     constructor(
         address[] memory _owners,
         address[] memory _assetProxyContracts,
@@ -32,11 +34,11 @@ contract TestAssetProxyOwner is
     )
         public
         AssetProxyOwner(_owners, _assetProxyContracts, _required, _secondsTimeLocked)
-    {
-    }
+    {}
     
     function testValidRemoveAuthorizedAddressAtIndexTx(uint256 id)
         public
+        view
         validRemoveAuthorizedAddressAtIndexTx(id)
         returns (bool)
     {
diff --git a/packages/contracts/src/2.0.0/test/TestLibBytes/TestLibBytes.sol b/packages/contracts/src/2.0.0/test/TestLibBytes/TestLibBytes.sol
index f52f635e1..00d861e61 100644
--- a/packages/contracts/src/2.0.0/test/TestLibBytes/TestLibBytes.sol
+++ b/packages/contracts/src/2.0.0/test/TestLibBytes/TestLibBytes.sol
@@ -16,8 +16,7 @@
 
 */
 
-pragma solidity ^0.4.24;
-pragma experimental ABIEncoderV2;
+pragma solidity 0.4.24;
 
 import "../../utils/LibBytes/LibBytes.sol";
 
diff --git a/packages/contracts/src/2.0.0/test/TestLibs/TestLibs.sol b/packages/contracts/src/2.0.0/test/TestLibs/TestLibs.sol
index df8eb55ce..5a349527b 100644
--- a/packages/contracts/src/2.0.0/test/TestLibs/TestLibs.sol
+++ b/packages/contracts/src/2.0.0/test/TestLibs/TestLibs.sol
@@ -16,7 +16,7 @@
 
 */
 
-pragma solidity ^0.4.24;
+pragma solidity 0.4.24;
 pragma experimental ABIEncoderV2;
 
 import "../../protocol/Exchange/libs/LibMath.sol";
@@ -32,7 +32,8 @@ contract TestLibs is
     function publicGetPartialAmount(
         uint256 numerator,
         uint256 denominator,
-        uint256 target)
+        uint256 target
+    )
         public
         pure
         returns (uint256 partialAmount)
@@ -48,7 +49,8 @@ contract TestLibs is
     function publicIsRoundingError(
         uint256 numerator,
         uint256 denominator,
-        uint256 target)
+        uint256 target
+    )
         public
         pure
         returns (bool isError)
diff --git a/packages/contracts/src/2.0.0/test/TestSignatureValidator/TestSignatureValidator.sol b/packages/contracts/src/2.0.0/test/TestSignatureValidator/TestSignatureValidator.sol
index 591ae3378..e1a610469 100644
--- a/packages/contracts/src/2.0.0/test/TestSignatureValidator/TestSignatureValidator.sol
+++ b/packages/contracts/src/2.0.0/test/TestSignatureValidator/TestSignatureValidator.sol
@@ -16,8 +16,7 @@
 
 */
 
-pragma solidity ^0.4.24;
-pragma experimental ABIEncoderV2;
+pragma solidity 0.4.24;
 
 import "../../protocol/Exchange/MixinSignatureValidator.sol";
 import "../../protocol/Exchange/MixinTransactions.sol";
diff --git a/packages/contracts/src/2.0.0/test/TestValidator/TestValidator.sol b/packages/contracts/src/2.0.0/test/TestValidator/TestValidator.sol
index 5076dedc9..6278aede0 100644
--- a/packages/contracts/src/2.0.0/test/TestValidator/TestValidator.sol
+++ b/packages/contracts/src/2.0.0/test/TestValidator/TestValidator.sol
@@ -16,7 +16,7 @@
 
 */
 
-pragma solidity ^0.4.24;
+pragma solidity 0.4.24;
 
 import "../../protocol/Exchange/interfaces/IValidator.sol";
 
@@ -27,7 +27,7 @@ contract TestValidator is
 
     // The single valid signer for this wallet.
     // solhint-disable-next-line var-name-mixedcase
-    address VALID_SIGNER;
+    address internal VALID_SIGNER;
 
     /// @dev constructs a new `TestValidator` with a single valid signer.
     /// @param validSigner The sole, valid signer.
@@ -40,6 +40,7 @@ contract TestValidator is
     /// @param signerAddress Address that should have signed the given hash.
     /// @param signature Proof of signing.
     /// @return Validity of signature.
+    // solhint-disable no-unused-vars
     function isValidSignature(
         bytes32 hash,
         address signerAddress,
@@ -51,4 +52,5 @@ contract TestValidator is
     {
         return (signerAddress == VALID_SIGNER);
     }
+    // solhint-enable no-unused-vars
 }
diff --git a/packages/contracts/src/2.0.0/test/TestWallet/TestWallet.sol b/packages/contracts/src/2.0.0/test/TestWallet/TestWallet.sol
index 07dfac588..0415823e3 100644
--- a/packages/contracts/src/2.0.0/test/TestWallet/TestWallet.sol
+++ b/packages/contracts/src/2.0.0/test/TestWallet/TestWallet.sol
@@ -16,7 +16,7 @@
 
 */
 
-pragma solidity ^0.4.24;
+pragma solidity 0.4.24;
 
 import "../../protocol/Exchange/interfaces/IWallet.sol";
 import "../../utils/LibBytes/LibBytes.sol";
@@ -27,11 +27,9 @@ contract TestWallet is
 {
     using LibBytes for bytes;
 
-    string constant LENGTH_65_REQUIRED = "LENGTH_65_REQUIRED";
-
     // The owner of this wallet.
     // solhint-disable-next-line var-name-mixedcase
-    address WALLET_OWNER;
+    address internal WALLET_OWNER;
 
     /// @dev constructs a new `TestWallet` with a single owner.
     /// @param walletOwner The owner of this wallet.
@@ -54,7 +52,7 @@ contract TestWallet is
     {
         require(
             eip712Signature.length == 65,
-            LENGTH_65_REQUIRED
+            "LENGTH_65_REQUIRED"
         );
 
         uint8 v = uint8(eip712Signature[0]);
diff --git a/packages/contracts/src/2.0.0/test/Whitelist/Whitelist.sol b/packages/contracts/src/2.0.0/test/Whitelist/Whitelist.sol
index 07bd7d531..60cac26ea 100644
--- a/packages/contracts/src/2.0.0/test/Whitelist/Whitelist.sol
+++ b/packages/contracts/src/2.0.0/test/Whitelist/Whitelist.sol
@@ -16,7 +16,7 @@
 
 */
 
-pragma solidity ^0.4.24;
+pragma solidity 0.4.24;
 pragma experimental ABIEncoderV2;
 
 import "../../protocol/Exchange/interfaces/IExchange.sol";
@@ -27,28 +27,22 @@ import "../../utils/Ownable/Ownable.sol";
 contract Whitelist is
     Ownable
 {
-    // Revert reasons
-    string constant MAKER_NOT_WHITELISTED = "MAKER_NOT_WHITELISTED"; // Maker address not whitelisted.
-    string constant TAKER_NOT_WHITELISTED = "TAKER_NOT_WHITELISTED"; // Taker address not whitelisted.
-    string constant INVALID_SENDER = "INVALID_SENDER"; // Sender must equal transaction origin.
 
     // Mapping of address => whitelist status.
     mapping (address => bool) public isWhitelisted;
 
     // Exchange contract.
-    // solhint-disable-next-line var-name-mixedcase
-    IExchange EXCHANGE;
+    // solhint-disable var-name-mixedcase
+    IExchange internal EXCHANGE;
+    bytes internal TX_ORIGIN_SIGNATURE;
+    // solhint-enable var-name-mixedcase
 
-    byte constant VALIDATOR_SIGNATURE_BYTE = "\x06";
-    // solhint-disable-next-line var-name-mixedcase
-    bytes TX_ORIGIN_SIGNATURE;
+    byte constant internal VALIDATOR_SIGNATURE_BYTE = "\x06";
 
     constructor (address _exchange)
         public
     {
-        // solhint-disable-next-line var-name-mixedcase
         EXCHANGE = IExchange(_exchange);
-        // solhint-disable-next-line var-name-mixedcase
         TX_ORIGIN_SIGNATURE = abi.encodePacked(address(this), VALIDATOR_SIGNATURE_BYTE);
     }
 
@@ -65,6 +59,27 @@ contract Whitelist is
         isWhitelisted[target] = isApproved;
     }
 
+    /// @dev Verifies signer is same as signer of current Ethereum transaction.
+    ///      NOTE: This function can currently be used to validate signatures coming from outside of this contract.
+    ///      Extra safety checks can be added for a production contract.
+    /// @param signerAddress Address that should have signed the given hash.
+    /// @param signature Proof of signing.
+    /// @return Validity of order signature.
+    // solhint-disable no-unused-vars
+    function isValidSignature(
+        bytes32 hash,
+        address signerAddress,
+        bytes signature
+    )
+        external
+        view
+        returns (bool isValid)
+    {
+        // solhint-disable-next-line avoid-tx-origin
+        return signerAddress == tx.origin;
+    }
+    // solhint-enable no-unused-vars
+
     /// @dev Fills an order using `msg.sender` as the taker.
     ///      The transaction will revert if both the maker and taker are not whitelisted.
     ///      Orders should specify this contract as the `senderAddress` in order to gaurantee
@@ -85,20 +100,21 @@ contract Whitelist is
 
         // This contract must be the entry point for the transaction.
         require(
+            // solhint-disable-next-line avoid-tx-origin
             takerAddress == tx.origin,
-            INVALID_SENDER
+            "INVALID_SENDER"
         );
 
         // Check if maker is on the whitelist.
         require(
             isWhitelisted[order.makerAddress],
-            MAKER_NOT_WHITELISTED
+            "MAKER_NOT_WHITELISTED"
         );
 
         // Check if taker is on the whitelist.
         require(
             isWhitelisted[takerAddress],
-            TAKER_NOT_WHITELISTED
+            "TAKER_NOT_WHITELISTED"
         );
 
         // Encode arguments into byte array.
@@ -117,22 +133,4 @@ contract Whitelist is
             TX_ORIGIN_SIGNATURE
         );
     }
-
-    /// @dev Verifies signer is same as signer of current Ethereum transaction.
-    ///      NOTE: This function can currently be used to validate signatures coming from outside of this contract.
-    ///      Extra safety checks can be added for a production contract.
-    /// @param signerAddress Address that should have signed the given hash.
-    /// @param signature Proof of signing.
-    /// @return Validity of order signature.
-    function isValidSignature(
-        bytes32 hash,
-        address signerAddress,
-        bytes signature
-    )
-        external
-        view
-        returns (bool isValid)
-    {
-        return signerAddress == tx.origin;
-    }
 }
diff --git a/packages/contracts/src/2.0.0/tokens/ERC20Token/ERC20Token.sol b/packages/contracts/src/2.0.0/tokens/ERC20Token/ERC20Token.sol
index 59dc7d7bf..d9950145d 100644
--- a/packages/contracts/src/2.0.0/tokens/ERC20Token/ERC20Token.sol
+++ b/packages/contracts/src/2.0.0/tokens/ERC20Token/ERC20Token.sol
@@ -16,20 +16,15 @@
 
 */
 
-pragma solidity ^0.4.24;
-pragma experimental ABIEncoderV2;
+pragma solidity 0.4.24;
 
 import "./IERC20Token.sol";
 
 
 contract ERC20Token is IERC20Token {
 
-    string constant INSUFFICIENT_BALANCE = "ERC20_INSUFFICIENT_BALANCE";
-    string constant INSUFFICIENT_ALLOWANCE = "ERC20_INSUFFICIENT_ALLOWANCE";
-    string constant OVERFLOW = "Transfer would result in an overflow.";
-
-    mapping (address => uint256) balances;
-    mapping (address => mapping (address => uint256)) allowed;
+    mapping (address => uint256) internal balances;
+    mapping (address => mapping (address => uint256)) internal allowed;
 
     uint256 public totalSupply;
 
@@ -39,11 +34,11 @@ contract ERC20Token is IERC20Token {
     {
         require(
             balances[msg.sender] >= _value,
-            INSUFFICIENT_BALANCE
+            "ERC20_INSUFFICIENT_BALANCE"
         );
         require(
             balances[_to] + _value >= balances[_to],
-            OVERFLOW
+            "OVERFLOW"
         );
         balances[msg.sender] -= _value;
         balances[_to] += _value;
@@ -57,15 +52,15 @@ contract ERC20Token is IERC20Token {
     {
         require(
             balances[_from] >= _value,
-            INSUFFICIENT_BALANCE
+            "ERC20_INSUFFICIENT_BALANCE"
         );
         require(
             allowed[_from][msg.sender] >= _value,
-            INSUFFICIENT_ALLOWANCE
+            "ERC20_INSUFFICIENT_ALLOWANCE"
         );
         require(
             balances[_to] + _value >= balances[_to],
-            OVERFLOW
+            "OVERFLOW"
         );
         balances[_to] += _value;
         balances[_from] -= _value;
@@ -84,7 +79,8 @@ contract ERC20Token is IERC20Token {
     }
 
     function balanceOf(address _owner)
-        public view
+        public
+        view
         returns (uint256)
     {
         return balances[_owner];
diff --git a/packages/contracts/src/2.0.0/tokens/ERC20Token/IERC20Token.sol b/packages/contracts/src/2.0.0/tokens/ERC20Token/IERC20Token.sol
index de4ed2af9..5ee5e1011 100644
--- a/packages/contracts/src/2.0.0/tokens/ERC20Token/IERC20Token.sol
+++ b/packages/contracts/src/2.0.0/tokens/ERC20Token/IERC20Token.sol
@@ -16,8 +16,7 @@
 
 */
 
-pragma solidity ^0.4.24;
-pragma experimental ABIEncoderV2;
+pragma solidity 0.4.24;
 
 
 contract IERC20Token {
@@ -60,6 +59,7 @@ contract IERC20Token {
         public view
         returns (uint256);
 
+    // solhint-disable-next-line no-simple-event-func-name
     event Transfer(
         address indexed _from,
         address indexed _to,
diff --git a/packages/contracts/src/2.0.0/tokens/ERC721Token/ERC721Token.sol b/packages/contracts/src/2.0.0/tokens/ERC721Token/ERC721Token.sol
index defb506a8..60603aa19 100644
--- a/packages/contracts/src/2.0.0/tokens/ERC721Token/ERC721Token.sol
+++ b/packages/contracts/src/2.0.0/tokens/ERC721Token/ERC721Token.sol
@@ -23,7 +23,7 @@ TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
 
-pragma solidity ^0.4.24;
+pragma solidity 0.4.24;
 
 import "./IERC721Token.sol";
 import "./IERC721Receiver.sol";
@@ -41,7 +41,7 @@ contract ERC721Token is
 {
     // Equals to `bytes4(keccak256("onERC721Received(address,uint256,bytes)"))`
     // which can be also obtained as `ERC721Receiver(0).onERC721Received.selector`
-    bytes4 constant ERC721_RECEIVED = 0xf0b9e5ba;
+    bytes4 constant internal ERC721_RECEIVED = 0xf0b9e5ba;
 
     // Mapping from token ID to owner
     mapping (uint256 => address) internal tokenOwner;
@@ -73,7 +73,7 @@ contract ERC721Token is
         _;
     }
 
-    function ERC721Token(
+    constructor (
         string _name,
         string _symbol)
         public
diff --git a/packages/contracts/src/2.0.0/tokens/ERC721Token/IERC721Receiver.sol b/packages/contracts/src/2.0.0/tokens/ERC721Token/IERC721Receiver.sol
index f72c75638..f2e8f3c88 100644
--- a/packages/contracts/src/2.0.0/tokens/ERC721Token/IERC721Receiver.sol
+++ b/packages/contracts/src/2.0.0/tokens/ERC721Token/IERC721Receiver.sol
@@ -23,7 +23,7 @@ TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
 
-pragma solidity ^0.4.24;
+pragma solidity 0.4.24;
 
 
 /**
@@ -38,7 +38,7 @@ contract IERC721Receiver {
     *  Equals to `bytes4(keccak256("onERC721Received(address,uint256,bytes)"))`,
     *  which can be also obtained as `ERC721Receiver(0).onERC721Received.selector`
     */
-    bytes4 constant ERC721_RECEIVED = 0xf0b9e5ba;
+    bytes4 constant internal ERC721_RECEIVED = 0xf0b9e5ba;
 
     /**
     * @notice Handle the receipt of an NFT
diff --git a/packages/contracts/src/2.0.0/tokens/ERC721Token/IERC721Token.sol b/packages/contracts/src/2.0.0/tokens/ERC721Token/IERC721Token.sol
index 0d64ee861..4d57ece38 100644
--- a/packages/contracts/src/2.0.0/tokens/ERC721Token/IERC721Token.sol
+++ b/packages/contracts/src/2.0.0/tokens/ERC721Token/IERC721Token.sol
@@ -23,7 +23,7 @@ TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
 
-pragma solidity ^0.4.24;
+pragma solidity 0.4.24;
 
 
 /**
@@ -40,11 +40,13 @@ contract IERC721Token {
         address indexed _to,
         uint256 _tokenId
     );
+
     event Approval(
         address indexed _owner,
         address indexed _approved,
         uint256 _tokenId
     );
+
     event ApprovalForAll(
         address indexed _owner,
         address indexed _operator,
@@ -55,6 +57,7 @@ contract IERC721Token {
         public
         view
         returns (string);
+
     function symbol()
         public
         view
@@ -64,10 +67,12 @@ contract IERC721Token {
         public
         view
         returns (uint256 _balance);
+
     function ownerOf(uint256 _tokenId)
         public
         view
         returns (address _owner);
+
     function exists(uint256 _tokenId)
         public
         view
@@ -75,6 +80,7 @@ contract IERC721Token {
 
     function approve(address _to, uint256 _tokenId)
         public;
+
     function getApproved(uint256 _tokenId)
         public
         view
@@ -82,6 +88,7 @@ contract IERC721Token {
 
     function setApprovalForAll(address _operator, bool _approved)
         public;
+
     function isApprovedForAll(address _owner, address _operator)
         public
         view
@@ -90,17 +97,22 @@ contract IERC721Token {
     function transferFrom(
         address _from,
         address _to,
-        uint256 _tokenId)
+        uint256 _tokenId
+    )
         public;
+
     function safeTransferFrom(
         address _from,
         address _to,
-        uint256 _tokenId)
+        uint256 _tokenId
+    )
         public;
+
     function safeTransferFrom(
         address _from,
         address _to,
         uint256 _tokenId,
-        bytes _data)
+        bytes _data
+    )
         public;
 }
diff --git a/packages/contracts/src/2.0.0/tokens/EtherToken/IEtherToken.sol b/packages/contracts/src/2.0.0/tokens/EtherToken/IEtherToken.sol
new file mode 100644
index 000000000..9e2e68766
--- /dev/null
+++ b/packages/contracts/src/2.0.0/tokens/EtherToken/IEtherToken.sol
@@ -0,0 +1,33 @@
+/*
+
+  Copyright 2018 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity 0.4.24;
+
+import "../ERC20Token/IERC20Token.sol";
+
+
+contract IEtherToken is
+    IERC20Token
+{
+    function deposit()
+        public
+        payable;
+    
+    function withdraw(uint256 amount)
+        public;
+}
diff --git a/packages/contracts/src/2.0.0/tokens/WETH9/WETH9.sol b/packages/contracts/src/2.0.0/tokens/EtherToken/WETH9.sol
index 378a507b9..1fdb04de5 100644
--- a/packages/contracts/src/2.0.0/tokens/WETH9/WETH9.sol
+++ b/packages/contracts/src/2.0.0/tokens/EtherToken/WETH9.sol
@@ -13,6 +13,7 @@
 // You should have received a copy of the GNU General Public License
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+// solhint-disable
 pragma solidity ^0.4.18;
 
 
diff --git a/packages/contracts/src/2.0.0/tokens/UnlimitedAllowanceToken/UnlimitedAllowanceToken.sol b/packages/contracts/src/2.0.0/tokens/UnlimitedAllowanceToken/UnlimitedAllowanceToken.sol
index 845324e4e..9feb5c914 100644
--- a/packages/contracts/src/2.0.0/tokens/UnlimitedAllowanceToken/UnlimitedAllowanceToken.sol
+++ b/packages/contracts/src/2.0.0/tokens/UnlimitedAllowanceToken/UnlimitedAllowanceToken.sol
@@ -16,15 +16,14 @@
 
 */
 
-pragma solidity ^0.4.24;
-pragma experimental ABIEncoderV2;
+pragma solidity 0.4.24;
 
 import "../ERC20Token/ERC20Token.sol";
 
 
 contract UnlimitedAllowanceToken is ERC20Token {
 
-    uint256 constant MAX_UINT = 2**256 - 1;
+    uint256 constant internal MAX_UINT = 2**256 - 1;
 
     /// @dev ERC20 transferFrom, modified such that an allowance of MAX_UINT represents an unlimited allowance. See https://github.com/ethereum/EIPs/issues/717
     /// @param _from Address to transfer from.
@@ -38,15 +37,15 @@ contract UnlimitedAllowanceToken is ERC20Token {
         uint256 allowance = allowed[_from][msg.sender];
         require(
             balances[_from] >= _value,
-            INSUFFICIENT_BALANCE
+            "ERC20_INSUFFICIENT_BALANCE"
         );
         require(
             allowance >= _value,
-            INSUFFICIENT_ALLOWANCE
+            "ERC20_INSUFFICIENT_ALLOWANCE"
         );
         require(
             balances[_to] + _value >= balances[_to],
-            OVERFLOW
+            "OVERFLOW"
         );
         balances[_to] += _value;
         balances[_from] -= _value;
diff --git a/packages/contracts/src/2.0.0/tokens/ZRXToken/ZRXToken.sol b/packages/contracts/src/2.0.0/tokens/ZRXToken/ZRXToken.sol
index ed0670072..28c0b2fb3 100644
--- a/packages/contracts/src/2.0.0/tokens/ZRXToken/ZRXToken.sol
+++ b/packages/contracts/src/2.0.0/tokens/ZRXToken/ZRXToken.sol
@@ -16,20 +16,24 @@
 
 */
 
-pragma solidity ^0.4.11;
+pragma solidity 0.4.11;
 
+// solhint-disable-next-line max-line-length
 import { UnlimitedAllowanceToken_v1 as UnlimitedAllowanceToken } from "../../../1.0.0/UnlimitedAllowanceToken/UnlimitedAllowanceToken_v1.sol";
 
 
-
 contract ZRXToken is UnlimitedAllowanceToken {
 
+    // solhint-disable const-name-snakecase
     uint8 constant public decimals = 18;
     uint public totalSupply = 10**27; // 1 billion tokens, 18 decimal places
     string constant public name = "0x Protocol Token";
     string constant public symbol = "ZRX";
+    // solhint-enableconst-name-snakecase
 
-    function ZRXToken() {
+    function ZRXToken()
+        public
+    {
         balances[msg.sender] = totalSupply;
     }
 }
diff --git a/packages/contracts/src/2.0.0/utils/LibBytes/LibBytes.sol b/packages/contracts/src/2.0.0/utils/LibBytes/LibBytes.sol
index c2fff5efb..01d34fa8f 100644
--- a/packages/contracts/src/2.0.0/utils/LibBytes/LibBytes.sol
+++ b/packages/contracts/src/2.0.0/utils/LibBytes/LibBytes.sol
@@ -16,7 +16,7 @@
 
 */
 
-pragma solidity ^0.4.24;
+pragma solidity 0.4.24;
 
 
 library LibBytes {
@@ -115,6 +115,7 @@ library LibBytes {
                     // Copy whole words front to back
                     // Note: the first check is always true,
                     // this could have been a do-while loop.
+                    // solhint-disable-next-line no-empty-blocks
                     for {} lt(source, sEnd) {} {
                         mstore(dest, mload(source))
                         source := add(source, 32)
@@ -145,6 +146,7 @@ library LibBytes {
                     // 2**255, so they can be safely re-interpreted as signed.
                     // Note: the first check is always true,
                     // this could have been a do-while loop.
+                    // solhint-disable-next-line no-empty-blocks
                     for {} slt(dest, dEnd) {} {
                         mstore(dEnd, mload(sEnd))
                         sEnd := sub(sEnd, 32)
@@ -157,13 +159,17 @@ library LibBytes {
             }
         }
     }
-    
+
     /// @dev Returns a slices from a byte array.
     /// @param b The byte array to take a slice from.
     /// @param from The starting index for the slice (inclusive).
     /// @param to The final index for the slice (exclusive).
     /// @return result The slice containing bytes at indices [from, to)
-    function slice(bytes memory b, uint256 from, uint256 to)
+    function slice(
+        bytes memory b,
+        uint256 from,
+        uint256 to
+    )
         internal
         pure
         returns (bytes memory result)
@@ -192,7 +198,11 @@ library LibBytes {
     /// @param to The final index for the slice (exclusive).
     /// @return result The slice containing bytes at indices [from, to)
     /// @dev When `from == 0`, the original array will match the slice. In other cases its state will be corrupted.
-    function sliceDestructive(bytes memory b, uint256 from, uint256 to)
+    function sliceDestructive(
+        bytes memory b,
+        uint256 from,
+        uint256 to
+    )
         internal
         pure
         returns (bytes memory result)
@@ -344,7 +354,10 @@ library LibBytes {
             // 1. Add index to address of bytes array
             // 2. Load 32-byte word from memory
             // 3. Apply 12-byte mask to obtain extra bytes occupying word of memory where we'll store the address
-            let neighbors := and(mload(add(b, index)), 0xffffffffffffffffffffffff0000000000000000000000000000000000000000)
+            let neighbors := and(
+                mload(add(b, index)),
+                0xffffffffffffffffffffffff0000000000000000000000000000000000000000
+            )
             
             // Make sure input address is clean.
             // (Solidity does not guarantee this)
@@ -509,7 +522,7 @@ library LibBytes {
         // Assert length of <b> is valid, given
         // length of input
         require(
-            b.length >= index + 32 /* 32 bytes to store length */ + input.length,
+            b.length >= index + 32 + input.length,  // 32 bytes to store length
             "GREATER_OR_EQUAL_TO_NESTED_BYTES_LENGTH_REQUIRED"
         );
 
diff --git a/packages/contracts/src/2.0.0/utils/Ownable/IOwnable.sol b/packages/contracts/src/2.0.0/utils/Ownable/IOwnable.sol
index e77680903..116b8dc89 100644
--- a/packages/contracts/src/2.0.0/utils/Ownable/IOwnable.sol
+++ b/packages/contracts/src/2.0.0/utils/Ownable/IOwnable.sol
@@ -1,5 +1,4 @@
-pragma solidity ^0.4.24;
-pragma experimental ABIEncoderV2;
+pragma solidity 0.4.24;
 
 /*
  * Ownable
diff --git a/packages/contracts/src/2.0.0/utils/Ownable/Ownable.sol b/packages/contracts/src/2.0.0/utils/Ownable/Ownable.sol
index 489793a95..aca65aad2 100644
--- a/packages/contracts/src/2.0.0/utils/Ownable/Ownable.sol
+++ b/packages/contracts/src/2.0.0/utils/Ownable/Ownable.sol
@@ -1,5 +1,4 @@
-pragma solidity ^0.4.24;
-pragma experimental ABIEncoderV2;
+pragma solidity 0.4.24;
 
 /*
  * Ownable
diff --git a/packages/contracts/src/2.0.0/utils/SafeMath/SafeMath.sol b/packages/contracts/src/2.0.0/utils/SafeMath/SafeMath.sol
index ec0a3fe76..4413244db 100644
--- a/packages/contracts/src/2.0.0/utils/SafeMath/SafeMath.sol
+++ b/packages/contracts/src/2.0.0/utils/SafeMath/SafeMath.sol
@@ -1,28 +1,27 @@
-pragma solidity ^0.4.24;
-pragma experimental ABIEncoderV2;
+pragma solidity 0.4.24;
 
 
 contract SafeMath {
-    function safeMul(uint a, uint b)
+    function safeMul(uint256 a, uint256 b)
         internal
         pure
         returns (uint256)
     {
-        uint c = a * b;
+        uint256 c = a * b;
         assert(a == 0 || c / a == b);
         return c;
     }
 
-    function safeDiv(uint a, uint b)
+    function safeDiv(uint256 a, uint256 b)
         internal
         pure
         returns (uint256)
     {
-        uint c = a / b;
+        uint256 c = a / b;
         return c;
     }
 
-    function safeSub(uint a, uint b)
+    function safeSub(uint256 a, uint256 b)
         internal
         pure
         returns (uint256)
@@ -31,12 +30,12 @@ contract SafeMath {
         return a - b;
     }
 
-    function safeAdd(uint a, uint b)
+    function safeAdd(uint256 a, uint256 b)
         internal
         pure
         returns (uint256)
     {
-        uint c = a + b;
+        uint256 c = a + b;
         assert(c >= a);
         return c;
     }