Split up mixins and interfaces

29 files changed, 508 insertions, 745 deletions

diff --git a/packages/contracts/src/contracts/current/protocol/AssetProxy/proxies/ERC20Proxy.sol b/packages/contracts/src/contracts/current/protocol/AssetProxy/ERC20Proxy.sol
index 7e9b41f33..5ebdb5095 100644
--- a/packages/contracts/src/contracts/current/protocol/AssetProxy/proxies/ERC20Proxy.sol
+++ b/packages/contracts/src/contracts/current/protocol/AssetProxy/ERC20Proxy.sol
@@ -19,9 +19,9 @@
 pragma solidity ^0.4.23;
 pragma experimental ABIEncoderV2;
 
-import "../../../utils/LibBytes/LibBytes.sol";
-import "../../../tokens/ERC20Token/IERC20Token.sol";
-import "../MixinAssetProxy.sol";
+import "../../utils/LibBytes/LibBytes.sol";
+import "../../tokens/ERC20Token/IERC20Token.sol";
+import "./MixinAssetProxy.sol";
 
 contract ERC20Proxy is
     LibBytes,
diff --git a/packages/contracts/src/contracts/current/protocol/AssetProxy/proxies/ERC721Proxy.sol b/packages/contracts/src/contracts/current/protocol/AssetProxy/ERC721Proxy.sol
index 4d52893b0..cc1a60f2e 100644
--- a/packages/contracts/src/contracts/current/protocol/AssetProxy/proxies/ERC721Proxy.sol
+++ b/packages/contracts/src/contracts/current/protocol/AssetProxy/ERC721Proxy.sol
@@ -19,9 +19,9 @@
 pragma solidity ^0.4.23;
 pragma experimental ABIEncoderV2;
 
-import "../../../utils/LibBytes/LibBytes.sol";
-import "../../../tokens/ERC721Token/ERC721Token.sol";
-import "../MixinAssetProxy.sol";
+import "../../utils/LibBytes/LibBytes.sol";
+import "../../tokens/ERC721Token/ERC721Token.sol";
+import "./MixinAssetProxy.sol";
 
 contract ERC721Proxy is
     LibBytes,
diff --git a/packages/contracts/src/contracts/current/protocol/AssetProxy/MixinAssetProxy.sol b/packages/contracts/src/contracts/current/protocol/AssetProxy/MixinAssetProxy.sol
index b96c84582..0535559ae 100644
--- a/packages/contracts/src/contracts/current/protocol/AssetProxy/MixinAssetProxy.sol
+++ b/packages/contracts/src/contracts/current/protocol/AssetProxy/MixinAssetProxy.sol
@@ -20,11 +20,9 @@ pragma solidity ^0.4.23;
 pragma experimental ABIEncoderV2;
 
 import "./mixins/MAssetProxy.sol";
-import "./IAssetProxy.sol";
 import "../../utils/Authorizable/Authorizable.sol";
 
 contract MixinAssetProxy is 
-    IAssetProxy,
     Authorizable,
     MAssetProxy
 {
diff --git a/packages/contracts/src/contracts/current/protocol/AssetProxy/IAssetProxy.sol b/packages/contracts/src/contracts/current/protocol/AssetProxy/interfaces/IAssetProxy.sol
index 7675d684b..1cdace0b5 100644
--- a/packages/contracts/src/contracts/current/protocol/AssetProxy/IAssetProxy.sol
+++ b/packages/contracts/src/contracts/current/protocol/AssetProxy/interfaces/IAssetProxy.sol
@@ -19,7 +19,7 @@
 pragma solidity ^0.4.23;
 pragma experimental ABIEncoderV2;
 
-import "../../utils/Authorizable/IAuthorizable.sol";
+import "../../../utils/Authorizable/IAuthorizable.sol";
 
 contract IAssetProxy is
     IAuthorizable
diff --git a/packages/contracts/src/contracts/current/protocol/AssetProxy/mixins/MAssetProxy.sol b/packages/contracts/src/contracts/current/protocol/AssetProxy/mixins/MAssetProxy.sol
index d1276a61c..e0ec8c4e1 100644
--- a/packages/contracts/src/contracts/current/protocol/AssetProxy/mixins/MAssetProxy.sol
+++ b/packages/contracts/src/contracts/current/protocol/AssetProxy/mixins/MAssetProxy.sol
@@ -19,7 +19,11 @@
 pragma solidity ^0.4.23;
 pragma experimental ABIEncoderV2;
 
-contract MAssetProxy {
+import "../interfaces/IAssetProxy.sol";
+
+contract MAssetProxy is
+    IAssetProxy
+{
 
     /// @dev Internal version of `transferFrom`.
     /// @param assetMetadata Encoded byte array.
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/IExchange.sol b/packages/contracts/src/contracts/current/protocol/Exchange/IExchange.sol
deleted file mode 100644
index ef2fb2a96..000000000
--- a/packages/contracts/src/contracts/current/protocol/Exchange/IExchange.sol
+++ /dev/null
@@ -1,289 +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 ^0.4.21;
-pragma experimental ABIEncoderV2;
-
-contract IExchange {
-
-    // Error Codes
-    enum Errors {
-        ORDER_EXPIRED,                    // Order has already expired
-        ORDER_FULLY_FILLED_OR_CANCELLED,  // Order has already been fully filled or cancelled
-        ROUNDING_ERROR_TOO_LARGE,         // Rounding error too large
-        INSUFFICIENT_BALANCE_OR_ALLOWANCE // Insufficient balance or allowance for token transfer
-    }
-
-    event LogError(uint8 indexed errorId, bytes32 indexed orderHash);
-
-    event LogFill(
-        address indexed maker,
-        address taker,
-        address indexed feeRecipient,
-        bytes makerAssetData,
-        bytes takerAssetData,
-        uint256 makerAssetFilledAmount,
-        uint256 takerAssetFilledAmount,
-        uint256 makerFeePaid,
-        uint256 takerFeePaid,
-        bytes32 indexed orderHash
-    );
-
-    event LogCancel(
-        address indexed maker,
-        address indexed feeRecipient,
-        bytes makerAssetData,
-        bytes takerAssetData,
-        uint256 makerAssetCancelledAmount,
-        uint256 takerAssetCancelledAmount,
-        bytes32 indexed orderHash
-    );
-
-    function ZRX_TOKEN_CONTRACT()
-      public view
-      returns (address);
-
-    function EXTERNAL_QUERY_GAS_LIMIT()
-      public view
-      returns (uint16);
-
-    function VERSION()
-      public view
-      returns (string);
-
-    function filled(bytes32)
-      public view
-      returns (uint256);
-
-    function cancelled(bytes32)
-      public view
-      returns (uint256);
-
-    /// @dev Calculates the sum of values already filled and cancelled for a given order.
-    /// @param orderHash The Keccak-256 hash of the given order.
-    /// @return Sum of values already filled and cancelled.
-    function getUnavailableTakerAssetAmount(bytes32 orderHash)
-        public view
-        returns (uint256 unavailableTakerAssetAmount);
-
-    /// @dev Calculates partial value given a numerator and denominator.
-    /// @param numerator Numerator.
-    /// @param denominator Denominator.
-    /// @param target Value to calculate partial of.
-    /// @return Partial value of target.
-    function getPartialAmount(uint256 numerator, uint256 denominator, uint256 target)
-        public pure
-        returns (uint256 partialAmount);
-
-    /// @dev Checks if rounding error > 0.1%.
-    /// @param numerator Numerator.
-    /// @param denominator Denominator.
-    /// @param target Value to multiply with numerator/denominator.
-    /// @return Rounding error is present.
-    function isRoundingError(uint256 numerator, uint256 denominator, uint256 target)
-        public pure
-        returns (bool isError);
-
-    /// @dev Calculates Keccak-256 hash of order with specified parameters.
-    /// @param orderAddresses Array of order's maker, taker, makerAsset, takerAsset, and feeRecipient.
-    /// @param orderValues Array of order's makerAssetAmount, takerAssetAmount, makerFee, takerFee, expirationTimestampInSec, and salt.
-    /// @return Keccak-256 hash of order.
-    function getOrderHash(address[5] orderAddresses, uint256[6] orderValues)
-        public view
-        returns (bytes32 orderHash);
-
-    /// @dev Verifies that an order signature is valid.
-    /// @param signer address of signer.
-    /// @param hash Signed Keccak-256 hash.
-    /// @param v ECDSA signature parameter v.
-    /// @param r ECDSA signature parameters r.
-    /// @param s ECDSA signature parameters s.
-    /// @return Validity of order signature.
-    function isValidSignature(
-        address signer,
-        bytes32 hash,
-        uint8 v,
-        bytes32 r,
-        bytes32 s)
-        public pure
-        returns (bool isValid);
-
-    /// @dev Fills the input order.
-    /// @param orderAddresses Array of order's maker, taker, makerAsset, takerAsset, and feeRecipient.
-    /// @param orderValues Array of order's makerAssetAmount, takerAssetAmount, makerFee, takerFee, expirationTimestampInSec, and salt.
-    /// @param takerAssetFillAmount Desired amount of takerAsset to fill.
-    /// @param v ECDSA signature parameter v.
-    /// @param r ECDSA signature parameters r.
-    /// @param s ECDSA signature parameters s.
-    /// @return Total amount of takerAsset filled in trade.
-    function fillOrder(
-          address[5] orderAddresses,
-          uint256[6] orderValues,
-          uint256 takerAssetFillAmount,
-          uint8 v,
-          bytes32 r,
-          bytes32 s)
-          public
-          returns (uint256 takerAssetFilledAmount);
-
-    /// @dev Cancels the input order.
-    /// @param orderAddresses Array of order's maker, taker, makerAsset, takerAsset, and feeRecipient.
-    /// @param orderValues Array of order's makerAssetAmount, takerAssetAmount, makerFee, takerFee, expirationTimestampInSec, and salt.
-    /// @param takerAssetCancelAmount Desired amount of takerAsset to cancel in order.
-    /// @return Amount of takerAsset cancelled.
-    function cancelOrder(
-        address[5] orderAddresses,
-        uint256[6] orderValues,
-        uint256 takerAssetCancelAmount)
-        public
-        returns (uint256 takerAssetCancelledAmount);
-
-    /// @dev Cancels all orders for a specified maker up to a certain time.
-    /// @param salt Orders created with a salt less or equal to this value will be cancelled.
-    function cancelOrdersUpTo(uint256 salt)
-        external;
-
-    /// @dev Fills an order with specified parameters and ECDSA signature. Throws if specified amount not filled entirely.
-    /// @param orderAddresses Array of order's maker, taker, makerAsset, takerAsset, and feeRecipient.
-    /// @param orderValues Array of order's makerAssetAmount, takerAssetAmount, makerFee, takerFee, expirationTimestampInSec, and salt.
-    /// @param takerAssetFillAmount Desired amount of takerAsset to fill.
-    /// @param v ECDSA signature parameter v.
-    /// @param r ECDSA signature parameters r.
-    /// @param s ECDSA signature parameters s.
-    function fillOrKillOrder(
-        address[5] orderAddresses,
-        uint256[6] orderValues,
-        uint256 takerAssetFillAmount,
-        uint8 v,
-        bytes32 r,
-        bytes32 s)
-        public;
-
-    /// @dev Fills an order with specified parameters and ECDSA signature. Returns false if the transaction would otherwise revert.
-    /// @param orderAddresses Array of order's maker, taker, makerAsset, takerAsset, and feeRecipient.
-    /// @param orderValues Array of order's makerAssetAmount, takerAssetAmount, makerFee, takerFee, expirationTimestampInSec, and salt.
-    /// @param takerAssetFillAmount Desired amount of takerAsset to fill.
-    /// @param v ECDSA signature parameter v.
-    /// @param r ECDSA signature parameters r.
-    /// @param s ECDSA signature parameters s.
-    /// @return Success if the transaction did not revert.
-    /// @return Total amount of takerAsset filled in trade.
-    function fillOrderNoThrow(
-        address[5] orderAddresses,
-        uint256[6] orderValues,
-        uint256 takerAssetFillAmount,
-        uint8 v,
-        bytes32 r,
-        bytes32 s)
-        public
-        returns (bool success, uint256 takerAssetFilledAmount);
-
-    /// @dev Synchronously executes multiple calls of fillOrder in a single transaction.
-    /// @param orderAddresses Array of address arrays containing individual order addresses.
-    /// @param orderValues Array of uint256 arrays containing individual order values.
-    /// @param takerAssetFillAmounts Array of desired amounts of takerAsset to fill in orders.
-    /// @param v Array ECDSA signature v parameters.
-    /// @param r Array of ECDSA signature r parameters.
-    /// @param s Array of ECDSA signature s parameters.
-    function batchFillOrders(
-        address[5][] orderAddresses,
-        uint256[6][] orderValues,
-        uint256[] takerAssetFillAmounts,
-        uint8[] v,
-        bytes32[] r,
-        bytes32[] s)
-        external;
-
-    /// @dev Synchronously executes multiple calls of fillOrKill in a single transaction.
-    /// @param orderAddresses Array of address arrays containing individual order addresses.
-    /// @param orderValues Array of uint256 arrays containing individual order values.
-    /// @param takerAssetFillAmounts Array of desired amounts of takerAsset to fill in orders.
-    /// @param v Array ECDSA signature v parameters.
-    /// @param r Array of ECDSA signature r parameters.
-    /// @param s Array of ECDSA signature s parameters.
-    function batchFillOrKillOrders(
-        address[5][] orderAddresses,
-        uint256[6][] orderValues,
-        uint256[] takerAssetFillAmounts,
-        uint8[] v,
-        bytes32[] r,
-        bytes32[] s)
-        external;
-
-    /// @dev Synchronously executes multiple calls of fillOrderNoThrow in a single transaction.
-    /// @param orderAddresses Array of address arrays containing individual order addresses.
-    /// @param orderValues Array of uint256 arrays containing individual order values.
-    /// @param takerAssetFillAmounts Array of desired amounts of takerAsset to fill in orders.
-    /// @param v Array ECDSA signature v parameters.
-    /// @param r Array of ECDSA signature r parameters.
-    /// @param s Array of ECDSA signature s parameters.
-    function batchFillOrdersNoThrow(
-        address[5][] orderAddresses,
-        uint256[6][] orderValues,
-        uint256[] takerAssetFillAmounts,
-        uint8[] v,
-        bytes32[] r,
-        bytes32[] s)
-        external;
-
-    /// @dev Synchronously executes multiple fill orders in a single transaction until total takerAssetFillAmount filled.
-    /// @param orderAddresses Array of address arrays containing individual order addresses.
-    /// @param orderValues Array of uint256 arrays containing individual order values.
-    /// @param takerAssetFillAmount Desired total amount of takerAsset to fill in orders.
-    /// @param v Array ECDSA signature v parameters.
-    /// @param r Array of ECDSA signature r parameters.
-    /// @param s Array of ECDSA signature s parameters.
-    /// @return Total amount of takerAssetFillAmount filled in orders.
-    function marketFillOrders(
-        address[5][] orderAddresses,
-        uint256[6][] orderValues,
-        uint256 takerAssetFillAmount,
-        uint8[] v,
-        bytes32[] r,
-        bytes32[] s)
-        external
-        returns (uint256 totalTakerAssetFilledAmount);
-
-    /// @dev Synchronously executes multiple calls of fillOrderNoThrow in a single transaction until total takerAssetFillAmount filled.
-    /// @param orderAddresses Array of address arrays containing individual order addresses.
-    /// @param orderValues Array of uint256 arrays containing individual order values.
-    /// @param takerAssetFillAmount Desired total amount of takerAsset to fill in orders.
-    /// @param v Array ECDSA signature v parameters.
-    /// @param r Array of ECDSA signature r parameters.
-    /// @param s Array of ECDSA signature s parameters.
-    /// @return Total amount of takerAssetFillAmount filled in orders.
-    function marketFillOrdersNoThrow(
-        address[5][] orderAddresses,
-        uint256[6][] orderValues,
-        uint256 takerAssetFillAmount,
-        uint8[] v,
-        bytes32[] r,
-        bytes32[] s)
-        external
-        returns (uint256 totalTakerAssetFilledAmount);
-
-    /// @dev Synchronously cancels multiple orders in a single transaction.
-    /// @param orderAddresses Array of address arrays containing individual order addresses.
-    /// @param orderValues Array of uint256 arrays containing individual order values.
-    /// @param takerAssetCancelAmounts Array of desired amounts of takerAsset to cancel in orders.
-    function batchCancelOrders(
-        address[5][] orderAddresses,
-        uint256[6][] orderValues,
-        uint256[] takerAssetCancelAmounts)
-        external;
-}
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/LibExchangeErrors.sol b/packages/contracts/src/contracts/current/protocol/Exchange/LibExchangeErrors.sol
deleted file mode 100644
index cbd6cac29..000000000
--- a/packages/contracts/src/contracts/current/protocol/Exchange/LibExchangeErrors.sol
+++ /dev/null
@@ -1,59 +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 ^0.4.23;
-pragma experimental ABIEncoderV2;
-
-contract LibExchangeErrors {
-
-    // Error Codes
-    enum Errors {
-        ORDER_EXPIRED,                     // Order has already expired
-        ORDER_FULLY_FILLED,                // Order has already been fully filled
-        ORDER_CANCELLED,                   // Order has already been cancelled
-        ROUNDING_ERROR_TOO_LARGE,          // Rounding error too large
-        INSUFFICIENT_BALANCE_OR_ALLOWANCE  // Insufficient balance or allowance for token transfer
-    }
-
-    event ExchangeError(uint8 indexed errorId, bytes32 indexed orderHash);
-
-    // Core revert reasons
-    string constant GREATER_THAN_ZERO_AMOUNT_REQUIRED = "Amount must be greater than 0.";
-    string constant SIGNATURE_VALIDATION_FAILED = "Signature validation failed.";
-    string constant INVALID_SENDER = "Invalid `msg.sender`.";
-    string constant INVALID_CONTEXT = "Function called in an invalid context.";
-    string constant INVALID_NEW_MAKER_EPOCH = "Specified salt must be greater than or equal to existing makerEpoch.";
-
-    // Transaction revert reasons
-    string constant DUPLICATE_TRANSACTION_HASH = "Transaction has already been executed.";
-    string constant TRANSACTION_EXECUTION_FAILED = "Transaction execution failed.";
-
-    // Wrapper revert reasons
-    string constant COMPLETE_FILL_FAILED = "Desired fill amount could not be completely filled.";
-    string constant ASSET_DATA_MISMATCH = "Asset data must be the same for each order.";
-
-    // Asset proxy dispatcher revert reasons
-    string constant GREATER_THAN_ZERO_LENGTH_REQUIRED = "Length must be greater than 0.";
-    string constant OLD_ASSET_PROXY_MISMATCH = "Old asset proxy does not match asset proxy at given id.";
-    string constant NEW_ASSET_PROXY_MISMATCH = "New asset proxy id does not match given id.";
-
-    // Signature validator revert reasons
-    string constant INVALID_SIGNATURE_LENGTH = "Invalid signature length.";
-    string constant ILLEGAL_SIGNATURE_TYPE = "Illegal signature type.";
-    string constant UNSUPPORTED_SIGNATURE_TYPE = "Unsupported signature type.";
-}
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/LibFillResults.sol b/packages/contracts/src/contracts/current/protocol/Exchange/LibFillResults.sol
deleted file mode 100644
index e26da2bce..000000000
--- a/packages/contracts/src/contracts/current/protocol/Exchange/LibFillResults.sol
+++ /dev/null
@@ -1,48 +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 ^0.4.23;
-pragma experimental ABIEncoderV2;
-
-import "../../utils/SafeMath/SafeMath.sol";
-
-contract LibFillResults is
-    SafeMath
-{
-
-    struct FillResults {
-        uint256 makerAssetFilledAmount;
-        uint256 takerAssetFilledAmount;
-        uint256 makerFeePaid;
-        uint256 takerFeePaid;
-    }
-
-    /// @dev Adds properties of both FillResults instances.
-    ///      Modifies the first FillResults instance specified.
-    /// @param totalFillResults Fill results instance that will be added onto.
-    /// @param singleFillResults Fill results instance that will be added to totalFillResults.
-    function addFillResults(FillResults memory totalFillResults, FillResults memory singleFillResults)
-        internal
-        pure
-    {
-        totalFillResults.makerAssetFilledAmount = safeAdd(totalFillResults.makerAssetFilledAmount, singleFillResults.makerAssetFilledAmount);
-        totalFillResults.takerAssetFilledAmount = safeAdd(totalFillResults.takerAssetFilledAmount, singleFillResults.takerAssetFilledAmount);
-        totalFillResults.makerFeePaid = safeAdd(totalFillResults.makerFeePaid, singleFillResults.makerFeePaid);
-        totalFillResults.takerFeePaid = safeAdd(totalFillResults.takerFeePaid, singleFillResults.takerFeePaid);
-    }
-}
\ No newline at end of file
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/LibMath.sol b/packages/contracts/src/contracts/current/protocol/Exchange/LibMath.sol
deleted file mode 100644
index 761c300a1..000000000
--- a/packages/contracts/src/contracts/current/protocol/Exchange/LibMath.sol
+++ /dev/null
@@ -1,73 +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 ^0.4.23;
-pragma experimental ABIEncoderV2;
-
-import "../../utils/SafeMath/SafeMath.sol";
-
-contract LibMath is
-    SafeMath
-{
-
-    /// @dev Calculates partial value given a numerator and denominator.
-    /// @param numerator Numerator.
-    /// @param denominator Denominator.
-    /// @param target Value to calculate partial of.
-    /// @return Partial value of target.
-    function getPartialAmount(
-        uint256 numerator,
-        uint256 denominator,
-        uint256 target)
-        internal
-        pure
-        returns (uint256 partialAmount)
-    {
-        partialAmount = safeDiv(
-            safeMul(numerator, target),
-            denominator
-        );
-        return partialAmount;
-    }
-
-    /// @dev Checks if rounding error > 0.1%.
-    /// @param numerator Numerator.
-    /// @param denominator Denominator.
-    /// @param target Value to multiply with numerator/denominator.
-    /// @return Rounding error is present.
-    function isRoundingError(
-        uint256 numerator,
-        uint256 denominator,
-        uint256 target)
-        internal
-        pure
-        returns (bool isError)
-    {
-        uint256 remainder = mulmod(target, numerator, denominator);
-        if (remainder == 0) {
-            return false; // No rounding error.
-        }
-
-        uint256 errPercentageTimes1000000 = safeDiv(
-            safeMul(remainder, 1000000),
-            safeMul(numerator, target)
-        );
-        isError = errPercentageTimes1000000 > 1000;
-        return isError;
-    }
-}
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/LibOrder.sol b/packages/contracts/src/contracts/current/protocol/Exchange/LibOrder.sol
deleted file mode 100644
index 32554f45b..000000000
--- a/packages/contracts/src/contracts/current/protocol/Exchange/LibOrder.sol
+++ /dev/null
@@ -1,85 +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 ^0.4.23;
-pragma experimental ABIEncoderV2;
-
-contract LibOrder {
-
-    bytes32 constant ORDER_SCHEMA_HASH = keccak256(
-        "address exchangeAddress",
-        "address makerAddress",
-        "address takerAddress",
-        "address feeRecipientAddress",
-        "address senderAddress",
-        "uint256 makerAssetAmount",
-        "uint256 takerAssetAmount",
-        "uint256 makerFee",
-        "uint256 takerFee",
-        "uint256 expirationTimeSeconds",
-        "uint256 salt",
-        "bytes makerAssetData",
-        "bytes takerAssetData"
-    );
-
-    struct Order {
-        address makerAddress;
-        address takerAddress;
-        address feeRecipientAddress;
-        address senderAddress;
-        uint256 makerAssetAmount;
-        uint256 takerAssetAmount;
-        uint256 makerFee;
-        uint256 takerFee;
-        uint256 expirationTimeSeconds;
-        uint256 salt;
-        bytes makerAssetData;
-        bytes takerAssetData;
-    }
-
-    /// @dev Calculates Keccak-256 hash of the order.
-    /// @param order The order structure.
-    /// @return Keccak-256 EIP712 hash of the order.
-    function getOrderHash(Order memory order)
-        internal
-        view
-        returns (bytes32 orderHash)
-    {
-        // TODO: EIP712 is not finalized yet
-        // Source: https://github.com/ethereum/EIPs/pull/712
-        orderHash = keccak256(
-            ORDER_SCHEMA_HASH,
-            keccak256(
-                address(this),
-                order.makerAddress,
-                order.takerAddress,
-                order.feeRecipientAddress,
-                order.senderAddress,
-                order.makerAssetAmount,
-                order.takerAssetAmount,
-                order.makerFee,
-                order.takerFee,
-                order.expirationTimeSeconds,
-                order.salt,
-                order.makerAssetData,
-                order.takerAssetData
-            )
-        );
-        return orderHash;
-    }
-}
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/MixinAssetProxyDispatcher.sol b/packages/contracts/src/contracts/current/protocol/Exchange/MixinAssetProxyDispatcher.sol
index eb423ad28..14d5eb7ca 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/MixinAssetProxyDispatcher.sol
+++ b/packages/contracts/src/contracts/current/protocol/Exchange/MixinAssetProxyDispatcher.sol
@@ -17,11 +17,10 @@
 */
 
 pragma solidity ^0.4.23;
-pragma experimental ABIEncoderV2;
 
 import "../../utils/Ownable/Ownable.sol";
-import "../AssetProxy/IAssetProxy.sol";
-import "./LibExchangeErrors.sol";
+import "../AssetProxy/interfaces/IAssetProxy.sol";
+import "./lib/LibExchangeErrors.sol";
 import "./mixins/MAssetProxyDispatcher.sol";
 
 contract MixinAssetProxyDispatcher is
@@ -32,33 +31,6 @@ contract MixinAssetProxyDispatcher is
     // Mapping from Asset Proxy Id's to their respective Asset Proxy
     mapping (uint8 => IAssetProxy) public assetProxies;
 
-    /// @dev Forwards arguments to assetProxy and calls `transferFrom`. Either succeeds or throws.
-    /// @param assetMetadata Byte array encoded for the respective asset proxy.
-    /// @param from Address to transfer token from.
-    /// @param to Address to transfer token to.
-    /// @param amount Amount of token to transfer.
-    function dispatchTransferFrom(
-        bytes memory assetMetadata,
-        address from,
-        address to,
-        uint256 amount)
-        internal
-    {
-        // Do nothing if no amount should be transferred.
-        if (amount > 0) {
-            // Lookup asset proxy
-            require(
-                assetMetadata.length >= 1,
-                GREATER_THAN_ZERO_LENGTH_REQUIRED
-            );
-            uint8 assetProxyId = uint8(assetMetadata[0]);
-            IAssetProxy assetProxy = assetProxies[assetProxyId];
-
-            // transferFrom will either succeed or throw.
-            assetProxy.transferFrom(assetMetadata, from, to, amount);
-        }
-    }
-
     /// @dev Registers an asset proxy to an asset proxy id.
     ///      An id can only be assigned to a single proxy at a given time.
     /// @param assetProxyId Id to register`newAssetProxy` under.
@@ -104,4 +76,31 @@ contract MixinAssetProxyDispatcher is
         address assetProxy = address(assetProxies[assetProxyId]);
         return assetProxy;
     }
+
+    /// @dev Forwards arguments to assetProxy and calls `transferFrom`. Either succeeds or throws.
+    /// @param assetMetadata Byte array encoded for the respective asset proxy.
+    /// @param from Address to transfer token from.
+    /// @param to Address to transfer token to.
+    /// @param amount Amount of token to transfer.
+    function dispatchTransferFrom(
+        bytes memory assetMetadata,
+        address from,
+        address to,
+        uint256 amount)
+        internal
+    {
+        // Do nothing if no amount should be transferred.
+        if (amount > 0) {
+            // Lookup asset proxy
+            require(
+                assetMetadata.length >= 1,
+                GREATER_THAN_ZERO_LENGTH_REQUIRED
+            );
+            uint8 assetProxyId = uint8(assetMetadata[0]);
+            IAssetProxy assetProxy = assetProxies[assetProxyId];
+
+            // transferFrom will either succeed or throw.
+            assetProxy.transferFrom(assetMetadata, from, to, amount);
+        }
+    }
 }
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/MixinExchangeCore.sol b/packages/contracts/src/contracts/current/protocol/Exchange/MixinExchangeCore.sol
index d764d7a4f..c22acf966 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/MixinExchangeCore.sol
+++ b/packages/contracts/src/contracts/current/protocol/Exchange/MixinExchangeCore.sol
@@ -19,18 +19,15 @@
 pragma solidity ^0.4.23;
 pragma experimental ABIEncoderV2;
 
-import "./LibFillResults.sol";
-import "./LibOrder.sol";
-import "./LibMath.sol";
-import "./LibExchangeErrors.sol";
+import "./lib/LibFillResults.sol";
+import "./lib/LibOrder.sol";
+import "./lib/LibMath.sol";
+import "./lib/LibExchangeErrors.sol";
 import "./mixins/MExchangeCore.sol";
 import "./mixins/MSettlement.sol";
 import "./mixins/MSignatureValidator.sol";
 import "./mixins/MTransactions.sol";
 
-/// @dev Provides MExchangeCore
-/// @dev Consumes MSettlement
-/// @dev Consumes MSignatureValidator
 contract MixinExchangeCore is
     LibOrder,
     LibFillResults,
@@ -51,35 +48,19 @@ contract MixinExchangeCore is
     // Orders with a salt less than their maker's epoch are considered cancelled
     mapping (address => uint256) public makerEpoch;
 
-    event Fill(
-        address indexed makerAddress,
-        address takerAddress,
-        address indexed feeRecipientAddress,
-        uint256 makerAssetFilledAmount,
-        uint256 takerAssetFilledAmount,
-        uint256 makerFeePaid,
-        uint256 takerFeePaid,
-        bytes32 indexed orderHash,
-        bytes makerAssetData,
-        bytes takerAssetData
-    );
-
-    event Cancel(
-        address indexed makerAddress,
-        address indexed feeRecipientAddress,
-        bytes32 indexed orderHash,
-        bytes makerAssetData,
-        bytes takerAssetData
-    );
-
-    event CancelUpTo(
-        address indexed makerAddress,
-        uint256 makerEpoch
-    );
-
-    /*
-    * Core exchange functions
-    */
+    /// @dev Cancels all orders reated by sender with a salt less than or equal to the specified salt value.
+    /// @param salt Orders created with a salt less or equal to this value will be cancelled.
+    function cancelOrdersUpTo(uint256 salt)
+        external
+    {
+        uint256 newMakerEpoch = salt + 1;  // makerEpoch is initialized to 0, so to cancelUpTo we need salt + 1
+        require(
+            newMakerEpoch > makerEpoch[msg.sender],  // epoch must be monotonically increasing
+            INVALID_NEW_MAKER_EPOCH
+        );
+        makerEpoch[msg.sender] = newMakerEpoch;
+        emit CancelUpTo(msg.sender, newMakerEpoch);
+    }
 
     /// @dev Fills the input order.
     /// @param order Order struct containing order specifications.
@@ -237,19 +218,6 @@ contract MixinExchangeCore is
         return true;
     }
 
-    /// @param salt Orders created with a salt less or equal to this value will be cancelled.
-    function cancelOrdersUpTo(uint256 salt)
-        external
-    {
-        uint256 newMakerEpoch = salt + 1;  // makerEpoch is initialized to 0, so to cancelUpTo we need salt + 1
-        require(
-            newMakerEpoch > makerEpoch[msg.sender],  // epoch must be monotonically increasing
-            INVALID_NEW_MAKER_EPOCH
-        );
-        makerEpoch[msg.sender] = newMakerEpoch;
-        emit CancelUpTo(msg.sender, newMakerEpoch);
-    }
-
     /// @dev Logs a Fill event with the given arguments.
     ///      The sole purpose of this function is to get around the stack variable limit.
     function emitFillEvent(
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/MixinSettlement.sol b/packages/contracts/src/contracts/current/protocol/Exchange/MixinSettlement.sol
index 3e805aa8e..ae1dd9bee 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/MixinSettlement.sol
+++ b/packages/contracts/src/contracts/current/protocol/Exchange/MixinSettlement.sol
@@ -17,22 +17,21 @@
 */
 
 pragma solidity ^0.4.23;
-pragma experimental ABIEncoderV2;
 
 import "./mixins/MSettlement.sol";
 import "./mixins/MAssetProxyDispatcher.sol";
-import "./LibOrder.sol";
-import "./LibMath.sol";
-import "../AssetProxy/IAssetProxy.sol";
+import "./lib/LibOrder.sol";
+import "./lib/LibMath.sol";
 
-/// @dev Provides MixinSettlement
 contract MixinSettlement is
     LibMath,
     MSettlement,
     MAssetProxyDispatcher
 {
+    /// ZRX metadata used for fee transfers.
     bytes internal ZRX_PROXY_DATA;
 
+    /// @dev Gets the ZRX metadata used for fee transfers.
     function zrxProxyData()
         external
         view
@@ -41,12 +40,20 @@ contract MixinSettlement is
         return ZRX_PROXY_DATA;
     }
 
+    /// TODO: _zrxProxyData should be a constant in production.
+    /// @dev Constructor sets the metadata that will be used for paying ZRX fees.
+    /// @param _zrxProxyData Byte array containing ERC20 proxy id concatenated with address of ZRX.
     constructor (bytes memory _zrxProxyData)
         public
     {
         ZRX_PROXY_DATA = _zrxProxyData;
     }
 
+    /// @dev Settles an order by transfering assets between counterparties.
+    /// @param order Order struct containing order specifications.
+    /// @param takerAddress Address selling takerAsset and buying makerAsset.
+    /// @param takerAssetFilledAmount The amount of takerAsset that will be transfered to the order's maker.
+    /// @return Amount filled by maker and fees paid by maker/taker.
     function settleOrder(
         LibOrder.Order memory order,
         address takerAddress,
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/MixinSignatureValidator.sol b/packages/contracts/src/contracts/current/protocol/Exchange/MixinSignatureValidator.sol
index 3091adcaf..43d138669 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/MixinSignatureValidator.sol
+++ b/packages/contracts/src/contracts/current/protocol/Exchange/MixinSignatureValidator.sol
@@ -17,33 +17,38 @@
 */
 
 pragma solidity ^0.4.23;
-pragma experimental ABIEncoderV2;
 
 import "./mixins/MSignatureValidator.sol";
-import "./ISigner.sol";
-import "./LibExchangeErrors.sol";
+import "./interfaces/ISigner.sol";
+import "./lib/LibExchangeErrors.sol";
 import "../../utils/LibBytes/LibBytes.sol";
 
-/// @dev Provides MSignatureValidator
 contract MixinSignatureValidator is
     LibBytes,
     LibExchangeErrors,
     MSignatureValidator
 {
-    enum SignatureType {
-        Illegal, // Default value
-        Invalid,
-        Caller,
-        Ecrecover,
-        EIP712,
-        Trezor,
-        Contract,
-        PreSigned
-    }
 
     // Mapping of hash => signer => signed
     mapping(bytes32 => mapping(address => bool)) preSigned;
 
+    /// @dev Approves a hash on-chain using any valid signature type.
+    ///      After presigning a hash, the preSign signature type will become valid for that hash and signer.
+    /// @param signer Address that should have signed the given hash.
+    /// @param signature Proof that the hash has been signed by signer.
+    function preSign(
+        bytes32 hash,
+        address signer,
+        bytes signature)
+        external
+    {
+        require(
+            isValidSignature(hash, signer, signature),
+            SIGNATURE_VALIDATION_FAILED
+        );
+        preSigned[hash][signer] = true;
+    }
+
     /// @dev Verifies that a hash has been signed by the given signer.
     /// @param hash Any 32 byte hash.
     /// @param signer Address that should have signed the given hash.
@@ -183,21 +188,4 @@ contract MixinSignatureValidator is
         // NOTE: Reason cannot be assigned to a variable because of https://github.com/ethereum/solidity/issues/4051
         revert("Unsupported signature type.");
     }
-
-    /// @dev Approves a hash on-chain using any valid signature type.
-    ///      After presigning a hash, the preSign signature type will become valid for that hash and signer.
-    /// @param signer Address that should have signed the given hash.
-    /// @param signature Proof that the hash has been signed by signer.
-    function preSign(
-        bytes32 hash,
-        address signer,
-        bytes signature)
-        external
-    {
-        require(
-            isValidSignature(hash, signer, signature),
-            SIGNATURE_VALIDATION_FAILED
-        );
-        preSigned[hash][signer] = true;
-    }
 }
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/MixinTransactions.sol b/packages/contracts/src/contracts/current/protocol/Exchange/MixinTransactions.sol
index 670d454d6..a8b60e8a4 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/MixinTransactions.sol
+++ b/packages/contracts/src/contracts/current/protocol/Exchange/MixinTransactions.sol
@@ -16,11 +16,10 @@
 
 */
 pragma solidity ^0.4.21;
-pragma experimental ABIEncoderV2;
 
 import "./mixins/MSignatureValidator.sol";
 import "./mixins/MTransactions.sol";
-import "./LibExchangeErrors.sol";
+import "./lib/LibExchangeErrors.sol";
 
 contract MixinTransactions is
     LibExchangeErrors,
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/MixinWrapperFunctions.sol b/packages/contracts/src/contracts/current/protocol/Exchange/MixinWrapperFunctions.sol
index 0cfcf0c25..33a125083 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/MixinWrapperFunctions.sol
+++ b/packages/contracts/src/contracts/current/protocol/Exchange/MixinWrapperFunctions.sol
@@ -21,12 +21,11 @@ pragma experimental ABIEncoderV2;
 
 import "../../utils/LibBytes/LibBytes.sol";
 import "./mixins/MExchangeCore.sol";
-import "./LibMath.sol";
-import "./LibOrder.sol";
-import "./LibFillResults.sol";
-import "./LibExchangeErrors.sol";
+import "./lib/LibMath.sol";
+import "./lib/LibOrder.sol";
+import "./lib/LibFillResults.sol";
+import "./lib/LibExchangeErrors.sol";
 
-/// @dev Consumes MExchangeCore
 contract MixinWrapperFunctions is
     LibOrder,
     LibFillResults,
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/interfaces/IAssetProxyDispatcher.sol b/packages/contracts/src/contracts/current/protocol/Exchange/interfaces/IAssetProxyDispatcher.sol
new file mode 100644
index 000000000..d60b8ca48
--- /dev/null
+++ b/packages/contracts/src/contracts/current/protocol/Exchange/interfaces/IAssetProxyDispatcher.sol
@@ -0,0 +1,41 @@
+/*
+
+  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 ^0.4.23;
+
+contract IAssetProxyDispatcher {
+
+    /// @dev Registers an asset proxy to an asset proxy id.
+    ///      An id can only be assigned to a single proxy at a given time.
+    /// @param assetProxyId Id to register`newAssetProxy` under.
+    /// @param newAssetProxy Address of new asset proxy to register, or 0x0 to unset assetProxyId.
+    /// @param oldAssetProxy Existing asset proxy to overwrite, or 0x0 if assetProxyId is currently unused.
+    function registerAssetProxy(
+        uint8 assetProxyId,
+        address newAssetProxy,
+        address oldAssetProxy)
+        external;
+
+    /// @dev Gets an asset proxy.
+    /// @param assetProxyId Id of the asset proxy.
+    /// @return The asset proxy registered to assetProxyId. Returns 0x0 if no proxy is registered.
+    function getAssetProxy(uint8 assetProxyId)
+        external
+        view
+        returns (address);
+}
\ No newline at end of file
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/interfaces/IExchange.sol b/packages/contracts/src/contracts/current/protocol/Exchange/interfaces/IExchange.sol
new file mode 100644
index 000000000..9fba3491b
--- /dev/null
+++ b/packages/contracts/src/contracts/current/protocol/Exchange/interfaces/IExchange.sol
@@ -0,0 +1,34 @@
+/*
+
+  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 ^0.4.23;
+pragma experimental ABIEncoderV2;
+
+import "./IExchangeCore.sol";
+import "./ISignatureValidator.sol";
+import "./IAssetProxyDispatcher.sol";
+import "./ITransactions.sol";
+import "./IWrapperFunctions.sol";
+
+contract IExchange is
+    IWrapperFunctions,
+    IExchangeCore,
+    ISignatureValidator,
+    ITransactions,
+    IAssetProxyDispatcher
+{}
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/interfaces/IExchangeCore.sol b/packages/contracts/src/contracts/current/protocol/Exchange/interfaces/IExchangeCore.sol
new file mode 100644
index 000000000..18f794ee8
--- /dev/null
+++ b/packages/contracts/src/contracts/current/protocol/Exchange/interfaces/IExchangeCore.sol
@@ -0,0 +1,51 @@
+/*
+
+  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 ^0.4.23;
+pragma experimental ABIEncoderV2;
+
+import "../lib/LibOrder.sol";
+import "../lib/LibFillResults.sol";
+
+contract IExchangeCore {
+
+    /// @dev Cancels all orders reated by sender with a salt less than or equal to the specified salt value.
+    /// @param salt Orders created with a salt less or equal to this value will be cancelled.
+    function cancelOrdersUpTo(uint256 salt)
+        external;
+
+    /// @dev Fills the input order.
+    /// @param order Order struct containing order specifications.
+    /// @param takerAssetFillAmount Desired amount of takerAsset to sell.
+    /// @param signature Proof that order has been created by maker.
+    /// @return Amounts filled and fees paid by maker and taker.
+    function fillOrder(
+        LibOrder.Order memory order,
+        uint256 takerAssetFillAmount,
+        bytes memory signature)
+        public
+        returns (LibFillResults.FillResults memory fillResults);
+
+    /// @dev After calling, the order can not be filled anymore.
+    /// @param order Order struct containing order specifications.
+    /// @return True if the order state changed to cancelled.
+    ///         False if the transaction was already cancelled or expired.
+    function cancelOrder(LibOrder.Order memory order)
+        public
+        returns (bool);
+}
\ No newline at end of file
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/interfaces/ISignatureValidator.sol b/packages/contracts/src/contracts/current/protocol/Exchange/interfaces/ISignatureValidator.sol
new file mode 100644
index 000000000..806d7c56f
--- /dev/null
+++ b/packages/contracts/src/contracts/current/protocol/Exchange/interfaces/ISignatureValidator.sol
@@ -0,0 +1,32 @@
+/*
+
+  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 ^0.4.23;
+
+contract ISignatureValidator {
+
+    /// @dev Approves a hash on-chain using any valid signature type.
+    ///      After presigning a hash, the preSign signature type will become valid for that hash and signer.
+    /// @param signer Address that should have signed the given hash.
+    /// @param signature Proof that the hash has been signed by signer.
+    function preSign(
+        bytes32 hash,
+        address signer,
+        bytes signature)
+        external;
+}
\ No newline at end of file
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/ISigner.sol b/packages/contracts/src/contracts/current/protocol/Exchange/interfaces/ISigner.sol
index d604a1aec..e065cfd8a 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/ISigner.sol
+++ b/packages/contracts/src/contracts/current/protocol/Exchange/interfaces/ISigner.sol
@@ -17,10 +17,13 @@
 */
 
 pragma solidity ^0.4.23;
-pragma experimental ABIEncoderV2;
 
 contract ISigner {
 
+    /// @dev Verifies that a signature is valid.
+    /// @param hash Message hash that is signed.
+    /// @param signature Proof of signing.
+    /// @return Validity of order signature.
     function isValidSignature(
         bytes32 hash,
         bytes signature)
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/interfaces/ITransactions.sol b/packages/contracts/src/contracts/current/protocol/Exchange/interfaces/ITransactions.sol
new file mode 100644
index 000000000..078b07816
--- /dev/null
+++ b/packages/contracts/src/contracts/current/protocol/Exchange/interfaces/ITransactions.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 ^0.4.23;
+
+contract ITransactions {
+
+    /// @dev Executes an exchange method call in the context of signer.
+    /// @param salt Arbitrary number to ensure uniqueness of transaction hash.
+    /// @param signer Address of transaction signer.
+    /// @param data AbiV2 encoded calldata.
+    /// @param signature Proof of signer transaction by signer.
+    function executeTransaction(
+        uint256 salt,
+        address signer,
+        bytes data,
+        bytes signature)
+        external;
+}
\ No newline at end of file
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/interfaces/IWrapperFunctions.sol b/packages/contracts/src/contracts/current/protocol/Exchange/interfaces/IWrapperFunctions.sol
new file mode 100644
index 000000000..0ebae309d
--- /dev/null
+++ b/packages/contracts/src/contracts/current/protocol/Exchange/interfaces/IWrapperFunctions.sol
@@ -0,0 +1,142 @@
+/*
+
+  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 ^0.4.23;
+pragma experimental ABIEncoderV2;
+
+import "./lib/LibOrder.sol";
+import "./lib/LibFillResults.sol";
+
+contract IWrapperFunctions is
+    LibOrder,
+    LibFillResults,
+    LibMath,
+    LibBytes,
+    LibExchangeErrors,
+    MExchangeCore
+{
+    /// @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.
+    /// @param signature Proof that order has been created by maker.
+    function fillOrKillOrder(
+        LibOrder.LibOrder.Order memory order,
+        uint256 takerAssetFillAmount,
+        bytes memory signature)
+        public
+        returns (LibFillResults.LibFillResults.FillResults memory fillResults);
+
+    /// @dev Fills an order with specified parameters and ECDSA signature.
+    ///      Returns false if the transaction would otherwise revert.
+    /// @param order LibOrder.Order struct containing order specifications.
+    /// @param takerAssetFillAmount Desired amount of takerAsset to sell.
+    /// @param signature Proof that order has been created by maker.
+    /// @return Amounts filled and fees paid by maker and taker.
+    function fillOrderNoThrow(
+        LibOrder.Order memory order,
+        uint256 takerAssetFillAmount,
+        bytes memory signature)
+        public
+        returns (LibFillResults.FillResults memory fillResults);
+
+    /// @dev Synchronously executes multiple calls of fillOrder.
+    /// @param orders Array of order specifications.
+    /// @param takerAssetFillAmounts Array of desired amounts of takerAsset to sell in orders.
+    /// @param signatures Proofs that orders have been created by makers.
+    function batchFillOrders(
+        LibOrder.Order[] memory orders,
+        uint256[] memory takerAssetFillAmounts,
+        bytes[] memory signatures)
+        public;
+
+    /// @dev Synchronously executes multiple calls of fillOrKill.
+    /// @param orders Array of order specifications.
+    /// @param takerAssetFillAmounts Array of desired amounts of takerAsset to sell in orders.
+    /// @param signatures Proofs that orders have been created by makers.
+    function batchFillOrKillOrders(
+        LibOrder.Order[] memory orders,
+        uint256[] memory takerAssetFillAmounts,
+        bytes[] memory signatures)
+        public;
+
+    /// @dev Fills an order with specified parameters and ECDSA signature.
+    ///      Returns false if the transaction would otherwise revert.
+    /// @param orders Array of order specifications.
+    /// @param takerAssetFillAmounts Array of desired amounts of takerAsset to sell in orders.
+    /// @param signatures Proofs that orders have been created by makers.
+    function batchFillOrdersNoThrow(
+        LibOrder.Order[] memory orders,
+        uint256[] memory takerAssetFillAmounts,
+        bytes[] memory signatures)
+        public;
+
+    /// @dev Synchronously executes multiple calls of fillOrder until total amount of takerAsset is sold by taker.
+    /// @param orders Array of order specifications.
+    /// @param takerAssetFillAmount Desired amount of takerAsset to sell.
+    /// @param signatures Proofs that orders have been created by makers.
+    /// @return Amounts filled and fees paid by makers and taker.
+    function marketSellOrders(
+        LibOrder.Order[] memory orders,
+        uint256 takerAssetFillAmount,
+        bytes[] memory signatures)
+        public
+        returns (LibFillResults.FillResults memory totalFillResults);
+
+    /// @dev Synchronously executes multiple calls of fillOrder until total amount of takerAsset is sold by taker.
+    ///      Returns false if the transaction would otherwise revert.
+    /// @param orders Array of order specifications.
+    /// @param takerAssetFillAmount Desired amount of takerAsset to sell.
+    /// @param signatures Proofs that orders have been signed by makers.
+    /// @return Amounts filled and fees paid by makers and taker.
+    function marketSellOrdersNoThrow(
+        LibOrder.Order[] memory orders,
+        uint256 takerAssetFillAmount,
+        bytes[] memory signatures)
+        public
+        returns (LibFillResults.FillResults memory totalFillResults);
+
+    /// @dev Synchronously executes multiple calls of fillOrder until total amount of makerAsset is bought by taker.
+    /// @param orders Array of order specifications.
+    /// @param makerAssetFillAmount Desired amount of makerAsset to buy.
+    /// @param signatures Proofs that orders have been signed by makers.
+    /// @return Amounts filled and fees paid by makers and taker.
+    function marketBuyOrders(
+        LibOrder.Order[] memory orders,
+        uint256 makerAssetFillAmount,
+        bytes[] memory signatures)
+        public
+        returns (LibFillResults.FillResults memory totalFillResults);
+
+    /// @dev Synchronously executes multiple fill orders in a single transaction until total amount is bought by taker.
+    ///      Returns false if the transaction would otherwise revert.
+    /// @param orders Array of order specifications.
+    /// @param makerAssetFillAmount Desired amount of makerAsset to buy.
+    /// @param signatures Proofs that orders have been signed by makers.
+    /// @return Amounts filled and fees paid by makers and taker.
+    function marketBuyOrdersNoThrow(
+        LibOrder.Order[] memory orders,
+        uint256 makerAssetFillAmount,
+        bytes[] memory signatures)
+        public
+        returns (LibFillResults.FillResults memory totalFillResults);
+
+    /// @dev Synchronously cancels multiple orders in a single transaction.
+    /// @param orders Array of order specifications.
+    function batchCancelOrders(LibOrder.Order[] memory orders)
+        public;
+}
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/mixins/MAssetProxyDispatcher.sol b/packages/contracts/src/contracts/current/protocol/Exchange/mixins/MAssetProxyDispatcher.sol
index df2250cd9..77ee77797 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/mixins/MAssetProxyDispatcher.sol
+++ b/packages/contracts/src/contracts/current/protocol/Exchange/mixins/MAssetProxyDispatcher.sol
@@ -17,9 +17,12 @@
 */
 
 pragma solidity ^0.4.23;
-pragma experimental ABIEncoderV2;
 
-contract MAssetProxyDispatcher {
+import "../interfaces/IAssetProxyDispatcher.sol";
+
+contract MAssetProxyDispatcher is
+    IAssetProxyDispatcher
+{
 
     // Logs registration of new asset proxy
     event AssetProxySet(
@@ -39,23 +42,4 @@ contract MAssetProxyDispatcher {
         address to,
         uint256 amount)
         internal;
-
-    /// @dev Registers an asset proxy to an asset proxy id.
-    ///      An id can only be assigned to a single proxy at a given time.
-    /// @param assetProxyId Id to register`newAssetProxy` under.
-    /// @param newAssetProxy Address of new asset proxy to register, or 0x0 to unset assetProxyId.
-    /// @param oldAssetProxy Existing asset proxy to overwrite, or 0x0 if assetProxyId is currently unused.
-    function registerAssetProxy(
-        uint8 assetProxyId,
-        address newAssetProxy,
-        address oldAssetProxy)
-        external;
-
-    /// @dev Gets an asset proxy.
-    /// @param assetProxyId Id of the asset proxy.
-    /// @return The asset proxy registered to assetProxyId. Returns 0x0 if no proxy is registered.
-    function getAssetProxy(uint8 assetProxyId)
-        external
-        view
-        returns (address);
 }
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/mixins/MExchangeCore.sol b/packages/contracts/src/contracts/current/protocol/Exchange/mixins/MExchangeCore.sol
index 6bd8fd9b6..b80af9dc1 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/mixins/MExchangeCore.sol
+++ b/packages/contracts/src/contracts/current/protocol/Exchange/mixins/MExchangeCore.sol
@@ -17,24 +17,50 @@
 */
 
 pragma solidity ^0.4.23;
-pragma experimental ABIEncoderV2;
 
-import "../LibOrder.sol";
-import "../LibFillResults.sol";
+import "../lib/LibOrder.sol";
+import "../lib/LibFillResults.sol";
+import "../interfaces/IExchangeCore.sol";
 
-contract MExchangeCore {
+contract MExchangeCore is
+    IExchangeCore
+{
 
-    function fillOrder(
-        LibOrder.Order memory order,
-        uint256 takerAssetFillAmount,
-        bytes memory signature)
-        public
-        returns (LibFillResults.FillResults memory fillResults);
+    // Fill event is emitted whenever an order is filled.
+    event Fill(
+        address indexed makerAddress,
+        address takerAddress,
+        address indexed feeRecipientAddress,
+        uint256 makerAssetFilledAmount,
+        uint256 takerAssetFilledAmount,
+        uint256 makerFeePaid,
+        uint256 takerFeePaid,
+        bytes32 indexed orderHash,
+        bytes makerAssetData,
+        bytes takerAssetData
+    );
+
+    // Cancel event is emitted whenever an individual order is cancelled.
+    event Cancel(
+        address indexed makerAddress,
+        address indexed feeRecipientAddress,
+        bytes32 indexed orderHash,
+        bytes makerAssetData,
+        bytes takerAssetData
+    );
 
-    function cancelOrder(LibOrder.Order memory order)
-        public
-        returns (bool);
+    // CancelUpTo event is emitted whenever `cancelOrdersUpTo` is executed succesfully.
+    event CancelUpTo(
+        address indexed makerAddress,
+        uint256 makerEpoch
+    );
 
-    function cancelOrdersUpTo(uint256 salt)
-        external;
+    /// @dev Logs a Fill event with the given arguments.
+    ///      The sole purpose of this function is to get around the stack variable limit.
+    function emitFillEvent(
+        LibOrder.Order memory order,
+        address takerAddress,
+        bytes32 orderHash,
+        LibFillResults.FillResults memory fillResults)
+        internal;
 }
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/mixins/MSettlement.sol b/packages/contracts/src/contracts/current/protocol/Exchange/mixins/MSettlement.sol
index 9cb2afeb0..3075aae15 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/mixins/MSettlement.sol
+++ b/packages/contracts/src/contracts/current/protocol/Exchange/mixins/MSettlement.sol
@@ -17,12 +17,16 @@
 */
 
 pragma solidity ^0.4.23;
-pragma experimental ABIEncoderV2;
 
-import "../LibOrder.sol";
+import "../lib/LibOrder.sol";
 
 contract MSettlement {
 
+    /// @dev Settles an order by transfering assets between counterparties.
+    /// @param order Order struct containing order specifications.
+    /// @param takerAddress Address selling takerAsset and buying makerAsset.
+    /// @param takerAssetFilledAmount The amount of takerAsset that will be transfered to the order's maker.
+    /// @return Amount filled by maker and fees paid by maker/taker.
     function settleOrder(
         LibOrder.Order memory order,
         address takerAddress,
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/mixins/MSignatureValidator.sol b/packages/contracts/src/contracts/current/protocol/Exchange/mixins/MSignatureValidator.sol
index 2b8ae78dd..ba26c07f6 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/mixins/MSignatureValidator.sol
+++ b/packages/contracts/src/contracts/current/protocol/Exchange/mixins/MSignatureValidator.sol
@@ -17,9 +17,23 @@
 */
 
 pragma solidity ^0.4.23;
-pragma experimental ABIEncoderV2;
 
-contract MSignatureValidator {
+import "../interfaces/ISignatureValidator.sol";
+
+contract MSignatureValidator is
+    ISignatureValidator
+{
+    // Allowed signature types.
+    enum SignatureType {
+        Illegal,  // Default value
+        Invalid,
+        Caller,
+        Ecrecover,
+        EIP712,
+        Trezor,
+        Contract,
+        PreSigned
+    }
 
     /// @dev Verifies that a signature is valid.
     /// @param hash Message hash that is signed.
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/mixins/MTransactions.sol b/packages/contracts/src/contracts/current/protocol/Exchange/mixins/MTransactions.sol
index 3d167c0bc..159ed1527 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/mixins/MTransactions.sol
+++ b/packages/contracts/src/contracts/current/protocol/Exchange/mixins/MTransactions.sol
@@ -16,21 +16,12 @@
 
 */
 pragma solidity ^0.4.23;
-pragma experimental ABIEncoderV2;
-
-contract MTransactions {
-
-    /// @dev Executes an exchange method call in the context of signer.
-    /// @param salt Arbitrary number to ensure uniqueness of transaction hash.
-    /// @param signer Address of transaction signer.
-    /// @param data AbiV2 encoded calldata.
-    /// @param signature Proof of signer transaction by signer.
-    function executeTransaction(
-        uint256 salt,
-        address signer,
-        bytes data,
-        bytes signature)
-        external;
+
+import "../interfaces/ITransactions.sol";
+
+contract MTransactions is
+    ITransactions
+{
 
     /// @dev The current function will be called in the context of this address (either 0x transaction signer or `msg.sender`).
     ///      If calling a fill function, this address will represent the taker.
diff --git a/packages/contracts/src/contracts/current/test/TestLibs/TestLibs.sol b/packages/contracts/src/contracts/current/test/TestLibs/TestLibs.sol
index 5a16ae947..3d199681b 100644
--- a/packages/contracts/src/contracts/current/test/TestLibs/TestLibs.sol
+++ b/packages/contracts/src/contracts/current/test/TestLibs/TestLibs.sol
@@ -19,9 +19,9 @@
 pragma solidity ^0.4.23;
 pragma experimental ABIEncoderV2;
 
-import "../../protocol/Exchange/LibMath.sol";
-import "../../protocol/Exchange/LibOrder.sol";
-import "../../protocol/Exchange/LibFillResults.sol";
+import "../../protocol/Exchange/lib/LibMath.sol";
+import "../../protocol/Exchange/lib/LibOrder.sol";
+import "../../protocol/Exchange/lib/LibFillResults.sol";
 
 contract TestLibs is 
     LibMath,