109 files changed, 695 insertions, 2525 deletions

diff --git a/packages/contracts/src/contracts/previous/Arbitrage/Arbitrage.sol b/packages/contracts/src/1.0.0/Arbitrage/Arbitrage.sol
index 5054afc2f..5054afc2f 100644
--- a/packages/contracts/src/contracts/previous/Arbitrage/Arbitrage.sol
+++ b/packages/contracts/src/1.0.0/Arbitrage/Arbitrage.sol
diff --git a/packages/contracts/src/contracts/previous/ERC20Token/ERC20Token_v1.sol b/packages/contracts/src/1.0.0/ERC20Token/ERC20Token_v1.sol
index e05ee2d5e..e05ee2d5e 100644
--- a/packages/contracts/src/contracts/previous/ERC20Token/ERC20Token_v1.sol
+++ b/packages/contracts/src/1.0.0/ERC20Token/ERC20Token_v1.sol
diff --git a/packages/contracts/src/contracts/previous/EtherDelta/AccountLevels.sol b/packages/contracts/src/1.0.0/EtherDelta/AccountLevels.sol
index 8d7a930d3..8d7a930d3 100644
--- a/packages/contracts/src/contracts/previous/EtherDelta/AccountLevels.sol
+++ b/packages/contracts/src/1.0.0/EtherDelta/AccountLevels.sol
diff --git a/packages/contracts/src/contracts/previous/EtherDelta/EtherDelta.sol b/packages/contracts/src/1.0.0/EtherDelta/EtherDelta.sol
index fe599ca0a..fe599ca0a 100644
--- a/packages/contracts/src/contracts/previous/EtherDelta/EtherDelta.sol
+++ b/packages/contracts/src/1.0.0/EtherDelta/EtherDelta.sol
diff --git a/packages/contracts/src/contracts/previous/Exchange/Exchange_v1.sol b/packages/contracts/src/1.0.0/Exchange/Exchange_v1.sol
index 3f8e7368d..3f8e7368d 100644
--- a/packages/contracts/src/contracts/previous/Exchange/Exchange_v1.sol
+++ b/packages/contracts/src/1.0.0/Exchange/Exchange_v1.sol
diff --git a/packages/contracts/src/contracts/previous/Exchange/IExchange_v1.sol b/packages/contracts/src/1.0.0/Exchange/IExchange_v1.sol
index ec4bce7b0..ec4bce7b0 100644
--- a/packages/contracts/src/contracts/previous/Exchange/IExchange_v1.sol
+++ b/packages/contracts/src/1.0.0/Exchange/IExchange_v1.sol
diff --git a/packages/contracts/src/contracts/previous/MultiSigWalletWithTImeLockExceptRemoveAuthorizedAddress/MultiSigWalletWithTimeLockExceptRemoveAuthorizedAddress.sol b/packages/contracts/src/1.0.0/MultiSigWalletWithTImeLockExceptRemoveAuthorizedAddress/MultiSigWalletWithTimeLockExceptRemoveAuthorizedAddress.sol
index 241e02d4a..241e02d4a 100644
--- a/packages/contracts/src/contracts/previous/MultiSigWalletWithTImeLockExceptRemoveAuthorizedAddress/MultiSigWalletWithTimeLockExceptRemoveAuthorizedAddress.sol
+++ b/packages/contracts/src/1.0.0/MultiSigWalletWithTImeLockExceptRemoveAuthorizedAddress/MultiSigWalletWithTimeLockExceptRemoveAuthorizedAddress.sol
diff --git a/packages/contracts/src/contracts/previous/Ownable/IOwnable_v1.sol b/packages/contracts/src/1.0.0/Ownable/IOwnable_v1.sol
index 7e22d544d..7e22d544d 100644
--- a/packages/contracts/src/contracts/previous/Ownable/IOwnable_v1.sol
+++ b/packages/contracts/src/1.0.0/Ownable/IOwnable_v1.sol
diff --git a/packages/contracts/src/contracts/previous/Ownable/Ownable_v1.sol b/packages/contracts/src/1.0.0/Ownable/Ownable_v1.sol
index c87438fa4..c87438fa4 100644
--- a/packages/contracts/src/contracts/previous/Ownable/Ownable_v1.sol
+++ b/packages/contracts/src/1.0.0/Ownable/Ownable_v1.sol
diff --git a/packages/contracts/src/contracts/previous/SafeMath/SafeMath_v1.sol b/packages/contracts/src/1.0.0/SafeMath/SafeMath_v1.sol
index 341d611ec..341d611ec 100644
--- a/packages/contracts/src/contracts/previous/SafeMath/SafeMath_v1.sol
+++ b/packages/contracts/src/1.0.0/SafeMath/SafeMath_v1.sol
diff --git a/packages/contracts/src/contracts/previous/Token/Token_v1.sol b/packages/contracts/src/1.0.0/Token/Token_v1.sol
index de619fb7e..de619fb7e 100644
--- a/packages/contracts/src/contracts/previous/Token/Token_v1.sol
+++ b/packages/contracts/src/1.0.0/Token/Token_v1.sol
diff --git a/packages/contracts/src/contracts/previous/TokenRegistry/ITokenRegistery.sol b/packages/contracts/src/1.0.0/TokenRegistry/ITokenRegistery.sol
index b8bdaf3b9..b8bdaf3b9 100644
--- a/packages/contracts/src/contracts/previous/TokenRegistry/ITokenRegistery.sol
+++ b/packages/contracts/src/1.0.0/TokenRegistry/ITokenRegistery.sol
diff --git a/packages/contracts/src/contracts/previous/TokenRegistry/TokenRegistry.sol b/packages/contracts/src/1.0.0/TokenRegistry/TokenRegistry.sol
index 7417a10a3..7417a10a3 100644
--- a/packages/contracts/src/contracts/previous/TokenRegistry/TokenRegistry.sol
+++ b/packages/contracts/src/1.0.0/TokenRegistry/TokenRegistry.sol
diff --git a/packages/contracts/src/contracts/previous/TokenTransferProxy/TokenTransferProxy_v1.sol b/packages/contracts/src/1.0.0/TokenTransferProxy/TokenTransferProxy_v1.sol
index e3659d8ba..e3659d8ba 100644
--- a/packages/contracts/src/contracts/previous/TokenTransferProxy/TokenTransferProxy_v1.sol
+++ b/packages/contracts/src/1.0.0/TokenTransferProxy/TokenTransferProxy_v1.sol
diff --git a/packages/contracts/src/contracts/previous/UnlimitedAllowanceToken/UnlimitedAllowanceToken_v1.sol b/packages/contracts/src/1.0.0/UnlimitedAllowanceToken/UnlimitedAllowanceToken_v1.sol
index 46379c43d..46379c43d 100644
--- a/packages/contracts/src/contracts/previous/UnlimitedAllowanceToken/UnlimitedAllowanceToken_v1.sol
+++ b/packages/contracts/src/1.0.0/UnlimitedAllowanceToken/UnlimitedAllowanceToken_v1.sol
diff --git a/packages/contracts/src/contracts/current/multisig/MultiSigWallet.sol b/packages/contracts/src/2.0.0/multisig/MultiSigWallet.sol
index 79fd92029..79fd92029 100644
--- a/packages/contracts/src/contracts/current/multisig/MultiSigWallet.sol
+++ b/packages/contracts/src/2.0.0/multisig/MultiSigWallet.sol
diff --git a/packages/contracts/src/contracts/current/multisig/MultiSigWalletWithTimeLock.sol b/packages/contracts/src/2.0.0/multisig/MultiSigWalletWithTimeLock.sol
index 9766c2158..9766c2158 100644
--- a/packages/contracts/src/contracts/current/multisig/MultiSigWalletWithTimeLock.sol
+++ b/packages/contracts/src/2.0.0/multisig/MultiSigWalletWithTimeLock.sol
diff --git a/packages/contracts/src/2.0.0/protocol/AssetProxy/ERC20Proxy.sol b/packages/contracts/src/2.0.0/protocol/AssetProxy/ERC20Proxy.sol
new file mode 100644
index 000000000..aed62f54f
--- /dev/null
+++ b/packages/contracts/src/2.0.0/protocol/AssetProxy/ERC20Proxy.sol
@@ -0,0 +1,132 @@
+/*
+
+  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 "./MixinAuthorizable.sol";
+
+contract ERC20Proxy is
+    MixinAuthorizable
+{
+    // Id of this proxy.
+    bytes4 constant PROXY_ID = bytes4(keccak256("ERC20Token(address)"));
+    
+    function () 
+        external
+    {
+        assembly {
+            // The first 4 bytes of calldata holds the function selector
+            let selector := and(calldataload(0), 0xffffffff00000000000000000000000000000000000000000000000000000000)
+
+            // `transferFrom` will be called with the following parameters:
+            // assetData Encoded byte array.
+            // from Address to transfer asset from.
+            // to Address to transfer asset to.
+            // amount Amount of asset to transfer.
+            // bytes4(keccak256("transferFrom(bytes,address,address,uint256)")) = 0xa85e59e4
+            if eq(selector, 0xa85e59e400000000000000000000000000000000000000000000000000000000) {
+
+                // To lookup a value in a mapping, we load from the storage location keccak256(k, p),
+                // where k is the key left padded to 32 bytes and p is the storage slot
+                let start := mload(64)
+                mstore(start, and(caller, 0xffffffffffffffffffffffffffffffffffffffff))
+                mstore(add(start, 32), authorized_slot)
+
+                // Revert if authorized[msg.sender] == false
+                if iszero(sload(keccak256(start, 64))) {
+                    // Revert with `Error("SENDER_NOT_AUTHORIZED")`
+                    mstore(0, 0x08c379a000000000000000000000000000000000000000000000000000000000)
+                    mstore(32, 0x0000002000000000000000000000000000000000000000000000000000000000)
+                    mstore(64, 0x0000001553454e4445525f4e4f545f415554484f52495a454400000000000000)
+                    mstore(96, 0)
+                    revert(0, 100)
+                }
+                
+                /////// Token contract address ///////
+                // The token address is found as follows:
+                // * It is stored at offset 4 in `assetData` contents.
+                // * This is stored at offset 32 from `assetData`.
+                // * The offset to `assetData` from Params is stored at offset
+                //   4 in calldata.
+                // * The offset of Params in calldata is 4.
+                // So we read location 4 and add 32 + 4 + 4 to it.
+                let token := calldataload(add(calldataload(4), 40))
+                
+                /////// Setup Header Area ///////
+                // This area holds the 4-byte `transferFrom` selector.
+                // Any trailing data in transferFromSelector will be
+                // overwritten in the next `mstore` call.
+                mstore(0, 0x23b872dd00000000000000000000000000000000000000000000000000000000)
+                
+                /////// Setup Params Area ///////
+                // We copy the fields `from`, `to` and `amount` in bulk
+                // from our own calldata to the new calldata.
+                calldatacopy(4, 36, 96)
+
+                /////// Call `token.transferFrom` using the calldata ///////
+                let success := call(
+                    gas,            // forward all gas
+                    token,          // call address of token contract
+                    0,              // don't send any ETH
+                    0,              // pointer to start of input
+                    100,            // length of input
+                    0,              // write output over input
+                    32              // output size should be 32 bytes
+                )
+
+                /////// Check return data. ///////
+                // If there is no return data, we assume the token incorrectly
+                // does not return a bool. In this case we expect it to revert
+                // on failure, which was handled above.
+                // If the token does return data, we require that it is a single
+                // nonzero 32 bytes value.
+                // So the transfer succeeded if the call succeeded and either
+                // returned nothing, or returned a non-zero 32 byte value. 
+                success := and(success, or(
+                    iszero(returndatasize),
+                    and(
+                        eq(returndatasize, 32),
+                        gt(mload(0), 0)
+                    )
+                ))
+                if success {
+                    return(0, 0)
+                }
+                
+                // Revert with `Error("TRANSFER_FAILED")`
+                mstore(0, 0x08c379a000000000000000000000000000000000000000000000000000000000)
+                mstore(32, 0x0000002000000000000000000000000000000000000000000000000000000000)
+                mstore(64, 0x0000000f5452414e534645525f4641494c454400000000000000000000000000)
+                mstore(96, 0)
+                revert(0, 100)
+            }
+        }
+    }
+
+    /// @dev Gets the proxy id associated with the proxy address.
+    /// @return Proxy id.
+    function getProxyId()
+        external
+        pure
+        returns (bytes4)
+    {
+        return PROXY_ID;
+    }
+}
diff --git a/packages/contracts/src/2.0.0/protocol/AssetProxy/ERC721Proxy.sol b/packages/contracts/src/2.0.0/protocol/AssetProxy/ERC721Proxy.sol
new file mode 100644
index 000000000..b73dc36cc
--- /dev/null
+++ b/packages/contracts/src/2.0.0/protocol/AssetProxy/ERC721Proxy.sol
@@ -0,0 +1,218 @@
+/*
+
+  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 "./MixinAuthorizable.sol";
+
+contract ERC721Proxy is
+    MixinAuthorizable
+{
+    // Id of this proxy.
+    bytes4 constant PROXY_ID = bytes4(keccak256("ERC721Token(address,uint256,bytes)"));
+
+    function () 
+        external
+    {
+        assembly {
+            // The first 4 bytes of calldata holds the function selector
+            let selector := and(calldataload(0), 0xffffffff00000000000000000000000000000000000000000000000000000000)
+
+            // `transferFrom` will be called with the following parameters:
+            // assetData Encoded byte array.
+            // from Address to transfer asset from.
+            // to Address to transfer asset to.
+            // amount Amount of asset to transfer.
+            // bytes4(keccak256("transferFrom(bytes,address,address,uint256)")) = 0xa85e59e4
+            if eq(selector, 0xa85e59e400000000000000000000000000000000000000000000000000000000) {
+
+                // To lookup a value in a mapping, we load from the storage location keccak256(k, p),
+                // where k is the key left padded to 32 bytes and p is the storage slot
+                let start := mload(64)
+                mstore(start, and(caller, 0xffffffffffffffffffffffffffffffffffffffff))
+                mstore(add(start, 32), authorized_slot)
+
+                // Revert if authorized[msg.sender] == false
+                if iszero(sload(keccak256(start, 64))) {
+                    // Revert with `Error("SENDER_NOT_AUTHORIZED")`
+                    mstore(0, 0x08c379a000000000000000000000000000000000000000000000000000000000)
+                    mstore(32, 0x0000002000000000000000000000000000000000000000000000000000000000)
+                    mstore(64, 0x0000001553454e4445525f4e4f545f415554484f52495a454400000000000000)
+                    mstore(96, 0)
+                    revert(0, 100)
+                }
+
+                // `transferFrom`.
+                // The function is marked `external`, so no abi decodeding is done for
+                // us. Instead, we expect the `calldata` memory to contain the
+                // following:
+                //
+                // | Area     | Offset | Length  | Contents                            |
+                // |----------|--------|---------|-------------------------------------|
+                // | Header   | 0      | 4       | function selector                   |
+                // | Params   |        | 4 * 32  | function parameters:                |
+                // |          | 4      |         |   1. offset to assetData (*)        |
+                // |          | 36     |         |   2. from                           |
+                // |          | 68     |         |   3. to                             |
+                // |          | 100    |         |   4. amount                         |
+                // | Data     |        |         | assetData:                          |
+                // |          | 132    | 32      | assetData Length                    |
+                // |          | 164    | **      | assetData Contents                  |
+                //
+                // (*): offset is computed from start of function parameters, so offset
+                //      by an additional 4 bytes in the calldata.
+                //
+                // WARNING: The ABIv2 specification allows additional padding between
+                //          the Params and Data section. This will result in a larger
+                //          offset to assetData.
+                
+                // Asset data itself is encoded as follows:
+                //
+                // | Area     | Offset | Length  | Contents                            |
+                // |----------|--------|---------|-------------------------------------|
+                // | Header   | 0      | 4       | function selector                   |
+                // | Params   |        | 3 * 32  | function parameters:                |
+                // |          | 4      | 12 + 20 |   1. token address                  |
+                // |          | 36     |         |   2. tokenId                        |
+                // |          | 68     |         |   3. offset to receiverData (*)     |
+                // | Data     |        |         | receiverData:                       |
+                // |          | 100    | 32      | receiverData Length                 |
+                // |          | 132    | **      | receiverData Contents               |
+                
+                // We construct calldata for the `token.safeTransferFrom` ABI.
+                // The layout of this calldata is in the table below.
+                // 
+                // | Area     | Offset | Length  | Contents                            |
+                // |----------|--------|---------|-------------------------------------|
+                // | Header   | 0      | 4       | function selector                   |
+                // | Params   |        | 4 * 32  | function parameters:                |
+                // |          | 4      |         |   1. from                           |
+                // |          | 36     |         |   2. to                             |
+                // |          | 68     |         |   3. tokenId                        |
+                // |          | 100    |         |   4. offset to receiverData (*)     |
+                // | Data     |        |         | receiverData:                       |
+                // |          | 132    | 32      | receiverData Length                 |
+                // |          | 164    | **      | receiverData Contents               |
+
+                // There exists only 1 of each token.
+                // require(amount == 1, "INVALID_AMOUNT")
+                if sub(calldataload(100), 1) {
+                    // Revert with `Error("INVALID_AMOUNT")`
+                    mstore(0, 0x08c379a000000000000000000000000000000000000000000000000000000000)
+                    mstore(32, 0x0000002000000000000000000000000000000000000000000000000000000000)
+                    mstore(64, 0x0000000e494e56414c49445f414d4f554e540000000000000000000000000000)
+                    mstore(96, 0)
+                    revert(0, 100)
+                }
+                
+                // Require assetData to be at least 132 bytes
+                let offset := calldataload(4)
+                if lt(calldataload(add(offset, 4)), 132) {
+                    // Revert with `Error("LENGTH_GREATER_THAN_131_REQUIRED")`
+                    mstore(0, 0x08c379a000000000000000000000000000000000000000000000000000000000)
+                    mstore(32, 0x0000002000000000000000000000000000000000000000000000000000000000)
+                    mstore(64, 0x000000204c454e4754485f475245415445525f5448414e5f3133315f52455155)
+                    mstore(96, 0x4952454400000000000000000000000000000000000000000000000000000000)
+                    revert(0, 100)
+                }
+                
+                /////// Setup State ///////
+                // `cdStart` is the start of the calldata for
+                // `token.safeTransferFrom` (equal to free memory ptr).
+                let cdStart := mload(64)
+                // `dataAreaLength` is the total number of words
+                // needed to store `receiverData`
+                // As-per the ABI spec, this value is padded up to
+                // the nearest multiple of 32,
+                // and includes 32-bytes for length.
+                // It's calculated as folows:
+                //      - Unpadded length in bytes = `mload(receiverData) + 32`
+                //      - Add 31 to convert rounding down to rounding up.
+                //        Combined with the previous and this is `63`.
+                //      - Round down to nearest multiple of 32 by clearing
+                //        bits 0x1F. This is done with `and` and a mask.
+
+                /////// Setup Header Area ///////
+                // This area holds the 4-byte `transferFromSelector`.
+                // Any trailing data in transferFromSelector will be
+                // overwritten in the next `mstore` call.
+                mstore(cdStart, 0xb88d4fde00000000000000000000000000000000000000000000000000000000)
+                
+                /////// Setup Params Area ///////
+                // Each parameter is padded to 32-bytes.
+                // The entire Params Area is 128 bytes.
+                // Notes:
+                //   1. A 20-byte mask is applied to addresses
+                //      to zero-out the unused bytes.
+                //   2. The offset to `receiverData` is the length
+                //      of the Params Area (128 bytes).
+                
+                let length := calldataload(add(offset, 136))
+                let token := calldataload(add(offset, 40))
+                
+                // Round length up to multiple of 32
+                length := and(add(length, 31), 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFE0)
+                
+                // Copy `from` and `to`
+                calldatacopy(add(cdStart, 4), 36, 64)
+                
+                // TokenId
+                mstore(add(cdStart, 68), calldataload(add(offset, 72)))
+                
+                // Offset to receiverData
+                mstore(add(cdStart, 100), 128)
+                
+                // receiverData (including length)
+                calldatacopy(add(cdStart, 132), add(offset, 136), add(length, 32))
+                
+                /////// Call `token.safeTransferFrom` using the calldata ///////
+                let success := call(
+                    gas,                    // forward all gas
+                    token,                  // call address of token contract
+                    0,                      // don't send any ETH
+                    cdStart,                // pointer to start of input
+                    add(length, 164),       // length of input
+                    0,                      // write output to null
+                    0                       // output size is 0 bytes
+                )
+                if success {
+                    return(0, 0)
+                }
+                
+                // Revert with `Error("TRANSFER_FAILED")`
+                mstore(0, 0x08c379a000000000000000000000000000000000000000000000000000000000)
+                mstore(32, 0x0000002000000000000000000000000000000000000000000000000000000000)
+                mstore(64, 0x0000000f5452414e534645525f4641494c454400000000000000000000000000)
+                mstore(96, 0)
+                revert(0, 100)
+            }
+        }
+    }
+
+    /// @dev Gets the proxy id associated with the proxy address.
+    /// @return Proxy id.
+    function getProxyId()
+        external
+        pure
+        returns (bytes4)
+    {
+        return PROXY_ID;
+    }
+}
diff --git a/packages/contracts/src/contracts/current/protocol/AssetProxy/MixinAuthorizable.sol b/packages/contracts/src/2.0.0/protocol/AssetProxy/MixinAuthorizable.sol
index 37c12f861..3b9584a44 100644
--- a/packages/contracts/src/contracts/current/protocol/AssetProxy/MixinAuthorizable.sol
+++ b/packages/contracts/src/2.0.0/protocol/AssetProxy/MixinAuthorizable.sol
@@ -19,12 +19,10 @@
 pragma solidity ^0.4.24;
 pragma experimental ABIEncoderV2;
 
-import "./libs/LibAssetProxyErrors.sol";
 import "../../utils/Ownable/Ownable.sol";
 import "./mixins/MAuthorizable.sol";
 
 contract MixinAuthorizable is
-    LibAssetProxyErrors,
     Ownable,
     MAuthorizable
 {
@@ -33,7 +31,7 @@ contract MixinAuthorizable is
     modifier onlyAuthorized {
         require(
             authorized[msg.sender],
-            SENDER_NOT_AUTHORIZED
+            "SENDER_NOT_AUTHORIZED"
         );
         _;
     }
@@ -49,7 +47,7 @@ contract MixinAuthorizable is
     {
         require(
             !authorized[target],
-            TARGET_ALREADY_AUTHORIZED
+            "TARGET_ALREADY_AUTHORIZED"
         );
 
         authorized[target] = true;
@@ -65,7 +63,7 @@ contract MixinAuthorizable is
     {
         require(
             authorized[target],
-            TARGET_NOT_AUTHORIZED
+            "TARGET_NOT_AUTHORIZED"
         );
 
         delete authorized[target];
@@ -91,15 +89,15 @@ contract MixinAuthorizable is
     {
         require(
             authorized[target],
-            TARGET_NOT_AUTHORIZED
+            "TARGET_NOT_AUTHORIZED"
         );
         require(
             index < authorities.length,
-            INDEX_OUT_OF_BOUNDS
+            "INDEX_OUT_OF_BOUNDS"
         );
         require(
             authorities[index] == target,
-            AUTHORIZED_ADDRESS_MISMATCH
+            "AUTHORIZED_ADDRESS_MISMATCH"
         );
 
         delete authorized[target];
diff --git a/packages/contracts/src/contracts/current/protocol/AssetProxy/libs/LibTransferErrors.sol b/packages/contracts/src/2.0.0/protocol/AssetProxy/interfaces/IAssetData.sol
index ba784ab22..7ebd6acf0 100644
--- a/packages/contracts/src/contracts/current/protocol/AssetProxy/libs/LibTransferErrors.sol
+++ b/packages/contracts/src/2.0.0/protocol/AssetProxy/interfaces/IAssetData.sol
@@ -16,10 +16,23 @@
 
 */
 
-pragma solidity ^0.4.24;
+pragma solidity ^0.4.23;
 
-contract LibTransferErrors {
-    /// Transfer errors ///
-    string constant INVALID_AMOUNT = "INVALID_AMOUNT";                            // Transfer amount must equal 1.
-    string constant TRANSFER_FAILED = "TRANSFER_FAILED";                          // Transfer failed.
+// @dev Interface of the asset proxy's assetData.
+// The asset proxies take an ABI encoded `bytes assetData` as argument.
+// This argument is ABI encoded as one of the methods of this interface.
+interface IAssetData {
+    
+    function ERC20Token(address tokenContract)
+        external
+        pure;
+    
+    function ERC721Token(
+        address tokenContract,
+        uint256 tokenId,
+        bytes receiverData
+    )
+        external
+        pure;
+    
 }
diff --git a/packages/contracts/src/contracts/current/protocol/AssetProxy/interfaces/IAssetProxy.sol b/packages/contracts/src/2.0.0/protocol/AssetProxy/interfaces/IAssetProxy.sol
index 22f43b12f..eacd5a412 100644
--- a/packages/contracts/src/contracts/current/protocol/AssetProxy/interfaces/IAssetProxy.sol
+++ b/packages/contracts/src/2.0.0/protocol/AssetProxy/interfaces/IAssetProxy.sol
@@ -38,24 +38,10 @@ contract IAssetProxy is
     )
         external;
     
-    /// @dev Makes multiple transfers of assets. Either succeeds or throws.
-    /// @param assetData Array of byte arrays encoded for the respective asset proxy.
-    /// @param from Array of addresses to transfer assets from.
-    /// @param to Array of addresses to transfer assets to.
-    /// @param amounts Array of amounts of assets to transfer.
-    function batchTransferFrom(
-        bytes[] memory assetData,
-        address[] memory from,
-        address[] memory to,
-        uint256[] memory amounts
-    )
-        public;
-
     /// @dev Gets the proxy id associated with the proxy address.
     /// @return Proxy id.
     function getProxyId()
         external
-        view
-        returns (uint8);
+        pure
+        returns (bytes4);
 }
-
diff --git a/packages/contracts/src/contracts/current/protocol/AssetProxy/interfaces/IAuthorizable.sol b/packages/contracts/src/2.0.0/protocol/AssetProxy/interfaces/IAuthorizable.sol
index cedd1744c..cedd1744c 100644
--- a/packages/contracts/src/contracts/current/protocol/AssetProxy/interfaces/IAuthorizable.sol
+++ b/packages/contracts/src/2.0.0/protocol/AssetProxy/interfaces/IAuthorizable.sol
diff --git a/packages/contracts/src/contracts/current/protocol/AssetProxy/libs/LibAssetProxyErrors.sol b/packages/contracts/src/2.0.0/protocol/AssetProxy/libs/LibAssetProxyErrors.sol
index dca4f400f..338cb12e2 100644
--- a/packages/contracts/src/contracts/current/protocol/AssetProxy/libs/LibAssetProxyErrors.sol
+++ b/packages/contracts/src/2.0.0/protocol/AssetProxy/libs/LibAssetProxyErrors.sol
@@ -18,11 +18,19 @@
 
 pragma solidity ^0.4.24;
 
+/// @dev This contract documents the revert reasons used in the AssetProxy contracts.
+/// This contract is intended to serve as a reference, but is not actually used for efficiency reasons.
 contract LibAssetProxyErrors {
+
     /// Authorizable errors ///
-    string constant SENDER_NOT_AUTHORIZED = "SENDER_NOT_AUTHORIZED";              // Sender not authorized to call this method.
-    string constant TARGET_NOT_AUTHORIZED = "TARGET_NOT_AUTHORIZED";              // Target address not authorized to call this method.
-    string constant TARGET_ALREADY_AUTHORIZED = "TARGET_ALREADY_AUTHORIZED";      // Target address must not already be authorized.
-    string constant INDEX_OUT_OF_BOUNDS = "INDEX_OUT_OF_BOUNDS";                  // Specified array index is out of bounds.
-    string constant AUTHORIZED_ADDRESS_MISMATCH = "AUTHORIZED_ADDRESS_MISMATCH";  // Address at index does not match given target address.
+    string constant SENDER_NOT_AUTHORIZED = "SENDER_NOT_AUTHORIZED";                        // Sender not authorized to call this method.
+    string constant TARGET_NOT_AUTHORIZED = "TARGET_NOT_AUTHORIZED";                        // Target address not authorized to call this method.
+    string constant TARGET_ALREADY_AUTHORIZED = "TARGET_ALREADY_AUTHORIZED";                // Target address must not already be authorized.
+    string constant INDEX_OUT_OF_BOUNDS = "INDEX_OUT_OF_BOUNDS";                            // Specified array index is out of bounds.
+    string constant AUTHORIZED_ADDRESS_MISMATCH = "AUTHORIZED_ADDRESS_MISMATCH";            // Address at index does not match given target address.
+
+    /// Transfer errors ///
+    string constant INVALID_AMOUNT = "INVALID_AMOUNT";                                      // Transfer amount must equal 1.
+    string constant TRANSFER_FAILED = "TRANSFER_FAILED";                                    // Transfer failed.
+    string constant LENGTH_GREATER_THAN_131_REQUIRED = "LENGTH_GREATER_THAN_131_REQUIRED";  // Byte array must have a length greater than 0.
 }
diff --git a/packages/contracts/src/contracts/current/protocol/AssetProxy/mixins/MAuthorizable.sol b/packages/contracts/src/2.0.0/protocol/AssetProxy/mixins/MAuthorizable.sol
index 6f35bd7ec..6f35bd7ec 100644
--- a/packages/contracts/src/contracts/current/protocol/AssetProxy/mixins/MAuthorizable.sol
+++ b/packages/contracts/src/2.0.0/protocol/AssetProxy/mixins/MAuthorizable.sol
diff --git a/packages/contracts/src/contracts/current/protocol/AssetProxyOwner/AssetProxyOwner.sol b/packages/contracts/src/2.0.0/protocol/AssetProxyOwner/AssetProxyOwner.sol
index eb58b3374..eb58b3374 100644
--- a/packages/contracts/src/contracts/current/protocol/AssetProxyOwner/AssetProxyOwner.sol
+++ b/packages/contracts/src/2.0.0/protocol/AssetProxyOwner/AssetProxyOwner.sol
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/Exchange.sol b/packages/contracts/src/2.0.0/protocol/Exchange/Exchange.sol
index d36e9633e..d36e9633e 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/Exchange.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/Exchange.sol
diff --git a/packages/contracts/src/2.0.0/protocol/Exchange/MixinAssetProxyDispatcher.sol b/packages/contracts/src/2.0.0/protocol/Exchange/MixinAssetProxyDispatcher.sol
new file mode 100644
index 000000000..9e9d88ce7
--- /dev/null
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/MixinAssetProxyDispatcher.sol
@@ -0,0 +1,175 @@
+/*
+
+  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 "../../utils/Ownable/Ownable.sol";
+import "../../utils/LibBytes/LibBytes.sol";
+import "./mixins/MAssetProxyDispatcher.sol";
+import "../AssetProxy/interfaces/IAssetProxy.sol";
+
+contract MixinAssetProxyDispatcher is
+    Ownable,
+    MAssetProxyDispatcher
+{
+    using LibBytes for bytes;
+    
+    // Mapping from Asset Proxy Id's to their respective Asset Proxy
+    mapping (bytes4 => IAssetProxy) public assetProxies;
+
+    /// @dev Registers an asset proxy to its asset proxy id.
+    ///      Once an asset proxy is registered, it cannot be unregistered.
+    /// @param assetProxy Address of new asset proxy to register.
+    function registerAssetProxy(address assetProxy)
+        external
+        onlyOwner
+    {
+        IAssetProxy assetProxyContract = IAssetProxy(assetProxy);
+
+        // Ensure that no asset proxy exists with current id.
+        bytes4 assetProxyId = assetProxyContract.getProxyId();
+        address currentAssetProxy = assetProxies[assetProxyId];
+        require(
+            currentAssetProxy == address(0),
+            "ASSET_PROXY_ALREADY_EXISTS"
+        );
+
+        // Add asset proxy and log registration.
+        assetProxies[assetProxyId] = assetProxyContract;
+        emit AssetProxyRegistered(
+            assetProxyId,
+            assetProxy
+        );
+    }
+
+    /// @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(bytes4 assetProxyId)
+        external
+        view
+        returns (address)
+    {
+        return assetProxies[assetProxyId];
+    }
+
+    /// @dev Forwards arguments to assetProxy and calls `transferFrom`. Either succeeds or throws.
+    /// @param assetData Byte array encoded for the asset.
+    /// @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 assetData,
+        address from,
+        address to,
+        uint256 amount
+    )
+        internal
+    {
+        // Do nothing if no amount should be transferred.
+        if (amount > 0) {
+            // Ensure assetData length is valid
+            require(
+                assetData.length > 3,
+                "LENGTH_GREATER_THAN_3_REQUIRED"
+            );
+            
+            // Lookup assetProxy
+            bytes4 assetProxyId;
+            assembly {
+                assetProxyId := and(mload(
+                    add(assetData, 32)),
+                    0xFFFFFFFF00000000000000000000000000000000000000000000000000000000
+                )
+            }
+            address assetProxy = assetProxies[assetProxyId];
+
+            // Ensure that assetProxy exists
+            require(
+                assetProxy != address(0),
+                "ASSET_PROXY_DOES_NOT_EXIST"
+            );
+            
+            // We construct calldata for the `assetProxy.transferFrom` ABI.
+            // The layout of this calldata is in the table below.
+            // 
+            // | Area     | Offset | Length  | Contents                                    |
+            // | -------- |--------|---------|-------------------------------------------- |
+            // | Header   | 0      | 4       | function selector                           |
+            // | Params   |        | 4 * 32  | function parameters:                        |
+            // |          | 4      |         |   1. offset to assetData (*)                |
+            // |          | 36     |         |   2. from                                   |
+            // |          | 68     |         |   3. to                                     |
+            // |          | 100    |         |   4. amount                                 |
+            // | Data     |        |         | assetData:                                  |
+            // |          | 132    | 32      | assetData Length                            |
+            // |          | 164    | **      | assetData Contents                          |
+
+            assembly {
+                /////// Setup State ///////
+                // `cdStart` is the start of the calldata for `assetProxy.transferFrom` (equal to free memory ptr).
+                let cdStart := mload(64)
+                // `dataAreaLength` is the total number of words needed to store `assetData`
+                //  As-per the ABI spec, this value is padded up to the nearest multiple of 32,
+                //  and includes 32-bytes for length.
+                let dataAreaLength := and(add(mload(assetData), 63), 0xFFFFFFFFFFFE0)
+                // `cdEnd` is the end of the calldata for `assetProxy.transferFrom`.
+                let cdEnd := add(cdStart, add(132, dataAreaLength))
+
+                
+                /////// Setup Header Area ///////
+                // This area holds the 4-byte `transferFromSelector`.
+                // bytes4(keccak256("transferFrom(bytes,address,address,uint256)")) = 0xa85e59e4
+                mstore(cdStart, 0xa85e59e400000000000000000000000000000000000000000000000000000000)
+                
+                /////// Setup Params Area ///////
+                // Each parameter is padded to 32-bytes. The entire Params Area is 128 bytes.
+                // Notes:
+                //   1. The offset to `assetData` is the length of the Params Area (128 bytes).
+                //   2. A 20-byte mask is applied to addresses to zero-out the unused bytes.
+                mstore(add(cdStart, 4), 128)
+                mstore(add(cdStart, 36), and(from, 0xffffffffffffffffffffffffffffffffffffffff))
+                mstore(add(cdStart, 68), and(to, 0xffffffffffffffffffffffffffffffffffffffff))
+                mstore(add(cdStart, 100), amount)
+                
+                /////// Setup Data Area ///////
+                // This area holds `assetData`.
+                let dataArea := add(cdStart, 132)
+                for {} lt(dataArea, cdEnd) {} {
+                    mstore(dataArea, mload(assetData))
+                    dataArea := add(dataArea, 32)
+                    assetData := add(assetData, 32)
+                }
+
+                /////// Call `assetProxy.transferFrom` using the constructed calldata ///////
+                let success := call(
+                    gas,                    // forward all gas
+                    assetProxy,             // call address of asset proxy
+                    0,                      // don't send any ETH
+                    cdStart,                // pointer to start of input
+                    sub(cdEnd, cdStart),    // length of input  
+                    cdStart,                // write output over input
+                    512                     // reserve 512 bytes for output
+                )
+                if iszero(success) {
+                    revert(cdStart, returndatasize())
+                }
+            }
+        }
+    }
+}
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/MixinExchangeCore.sol b/packages/contracts/src/2.0.0/protocol/Exchange/MixinExchangeCore.sol
index b207b3e57..c0ed023ac 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/MixinExchangeCore.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/MixinExchangeCore.sol
@@ -20,11 +20,9 @@ pragma solidity ^0.4.24;
 pragma experimental ABIEncoderV2;
 
 import "./libs/LibConstants.sol";
-import "../../utils/LibBytes/LibBytes.sol";
 import "./libs/LibFillResults.sol";
 import "./libs/LibOrder.sol";
 import "./libs/LibMath.sol";
-import "./libs/LibExchangeErrors.sol";
 import "./mixins/MExchangeCore.sol";
 import "./mixins/MSignatureValidator.sol";
 import "./mixins/MTransactions.sol";
@@ -35,14 +33,11 @@ contract MixinExchangeCore is
     LibMath,
     LibOrder,
     LibFillResults,
-    LibExchangeErrors,
     MAssetProxyDispatcher,
     MExchangeCore,
     MSignatureValidator,
     MTransactions
 {
-    using LibBytes for bytes;
-    
     // Mapping of orderHash => amount of takerAsset already bought by maker
     mapping (bytes32 => uint256) public filled;
 
@@ -73,7 +68,7 @@ contract MixinExchangeCore is
         // Ensure orderEpoch is monotonically increasing
         require(
             newOrderEpoch > oldOrderEpoch, 
-            INVALID_NEW_ORDER_EPOCH
+            "INVALID_NEW_ORDER_EPOCH"
         );
 
         // Update orderEpoch
@@ -285,20 +280,20 @@ contract MixinExchangeCore is
         // An order can only be filled if its status is FILLABLE.
         require(
             orderInfo.orderStatus == uint8(OrderStatus.FILLABLE),
-            ORDER_UNFILLABLE
+            "ORDER_UNFILLABLE"
         );
 
         // Revert if fill amount is invalid
         require(
             takerAssetFillAmount != 0,
-            INVALID_TAKER_AMOUNT
+            "INVALID_TAKER_AMOUNT"
         );
 
         // Validate sender is allowed to fill this order
         if (order.senderAddress != address(0)) {
             require(
                 order.senderAddress == msg.sender,
-                INVALID_SENDER
+                "INVALID_SENDER"
             );
         }
 
@@ -306,7 +301,7 @@ contract MixinExchangeCore is
         if (order.takerAddress != address(0)) {
             require(
                 order.takerAddress == takerAddress,
-                INVALID_TAKER
+                "INVALID_TAKER"
             );
         }
 
@@ -318,7 +313,7 @@ contract MixinExchangeCore is
                     order.makerAddress,
                     signature
                 ),
-                INVALID_ORDER_SIGNATURE
+                "INVALID_ORDER_SIGNATURE"
             );
         }
 
@@ -329,7 +324,7 @@ contract MixinExchangeCore is
                 order.takerAssetAmount,
                 order.makerAssetAmount
             ),
-            ROUNDING_ERROR
+            "ROUNDING_ERROR"
         );
     }
 
@@ -347,14 +342,14 @@ contract MixinExchangeCore is
         // An order can only be cancelled if its status is FILLABLE.
         require(
             orderInfo.orderStatus == uint8(OrderStatus.FILLABLE),
-            ORDER_UNFILLABLE
+            "ORDER_UNFILLABLE"
         );
 
         // Validate sender is allowed to cancel this order
         if (order.senderAddress != address(0)) {
             require(
                 order.senderAddress == msg.sender,
-                INVALID_SENDER
+                "INVALID_SENDER"
             );
         }
 
@@ -362,7 +357,7 @@ contract MixinExchangeCore is
         address makerAddress = getCurrentContextAddress();
         require(
             order.makerAddress == makerAddress,
-            INVALID_MAKER
+            "INVALID_MAKER"
         );
     }
 
@@ -412,33 +407,27 @@ contract MixinExchangeCore is
     )
         private
     {
-        uint8 makerAssetProxyId = uint8(order.makerAssetData.popLastByte());
-        uint8 takerAssetProxyId = uint8(order.takerAssetData.popLastByte());
         bytes memory zrxAssetData = ZRX_ASSET_DATA;
         dispatchTransferFrom(
             order.makerAssetData,
-            makerAssetProxyId,
             order.makerAddress,
             takerAddress,
             fillResults.makerAssetFilledAmount
         );
         dispatchTransferFrom(
             order.takerAssetData,
-            takerAssetProxyId,
             takerAddress,
             order.makerAddress,
             fillResults.takerAssetFilledAmount
         );
         dispatchTransferFrom(
             zrxAssetData,
-            ZRX_PROXY_ID,
             order.makerAddress,
             order.feeRecipientAddress,
             fillResults.makerFeePaid
         );
         dispatchTransferFrom(
             zrxAssetData,
-            ZRX_PROXY_ID,
             takerAddress,
             order.feeRecipientAddress,
             fillResults.takerFeePaid
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/MixinMatchOrders.sol b/packages/contracts/src/2.0.0/protocol/Exchange/MixinMatchOrders.sol
index e36fcc2c5..1a43eec79 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/MixinMatchOrders.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/MixinMatchOrders.sol
@@ -15,11 +15,9 @@ pragma solidity ^0.4.24;
 pragma experimental ABIEncoderV2;
 
 import "./libs/LibConstants.sol";
-import "../../utils/LibBytes/LibBytes.sol";
 import "./libs/LibMath.sol";
 import "./libs/LibOrder.sol";
 import "./libs/LibFillResults.sol";
-import "./libs/LibExchangeErrors.sol";
 import "./mixins/MExchangeCore.sol";
 import "./mixins/MMatchOrders.sol";
 import "./mixins/MTransactions.sol";
@@ -28,14 +26,11 @@ import "./mixins/MAssetProxyDispatcher.sol";
 contract MixinMatchOrders is
     LibConstants,
     LibMath,
-    LibExchangeErrors,
     MAssetProxyDispatcher,
     MExchangeCore,
     MMatchOrders,
     MTransactions
 {
-    using LibBytes for bytes;
-
     /// @dev Match two complementary orders that have a profitable spread.
     ///      Each order is filled at their respective price point. However, the calculations are
     ///      carried out as though the orders are both being filled at the right order's price point.
@@ -144,7 +139,7 @@ contract MixinMatchOrders is
         require(
             safeMul(leftOrder.makerAssetAmount, rightOrder.makerAssetAmount) >=
             safeMul(leftOrder.takerAssetAmount, rightOrder.takerAssetAmount),
-            NEGATIVE_SPREAD_REQUIRED
+            "NEGATIVE_SPREAD_REQUIRED"
         );
     }
 
@@ -242,27 +237,22 @@ contract MixinMatchOrders is
     )
         private
     {
-        uint8 leftMakerAssetProxyId = uint8(leftOrder.makerAssetData.popLastByte());
-        uint8 rightMakerAssetProxyId = uint8(rightOrder.makerAssetData.popLastByte());
         bytes memory zrxAssetData = ZRX_ASSET_DATA;
         // Order makers and taker
         dispatchTransferFrom(
             leftOrder.makerAssetData,
-            leftMakerAssetProxyId,
             leftOrder.makerAddress,
             rightOrder.makerAddress,
             matchedFillResults.right.takerAssetFilledAmount
         );
         dispatchTransferFrom(
             rightOrder.makerAssetData,
-            rightMakerAssetProxyId,
             rightOrder.makerAddress,
             leftOrder.makerAddress,
             matchedFillResults.left.takerAssetFilledAmount
         );
         dispatchTransferFrom(
             leftOrder.makerAssetData,
-            leftMakerAssetProxyId,
             leftOrder.makerAddress,
             takerAddress,
             matchedFillResults.leftMakerAssetSpreadAmount
@@ -271,14 +261,12 @@ contract MixinMatchOrders is
         // Maker fees
         dispatchTransferFrom(
             zrxAssetData,
-            ZRX_PROXY_ID,
             leftOrder.makerAddress,
             leftOrder.feeRecipientAddress,
             matchedFillResults.left.makerFeePaid
         );
         dispatchTransferFrom(
             zrxAssetData,
-            ZRX_PROXY_ID,
             rightOrder.makerAddress,
             rightOrder.feeRecipientAddress,
             matchedFillResults.right.makerFeePaid
@@ -288,7 +276,6 @@ contract MixinMatchOrders is
         if (leftOrder.feeRecipientAddress == rightOrder.feeRecipientAddress) {
             dispatchTransferFrom(
                 zrxAssetData,
-                ZRX_PROXY_ID,
                 takerAddress,
                 leftOrder.feeRecipientAddress,
                 safeAdd(
@@ -299,14 +286,12 @@ contract MixinMatchOrders is
         } else {
             dispatchTransferFrom(
                 zrxAssetData,
-                ZRX_PROXY_ID,
                 takerAddress,
                 leftOrder.feeRecipientAddress,
                 matchedFillResults.left.takerFeePaid
             );
             dispatchTransferFrom(
                 zrxAssetData,
-                ZRX_PROXY_ID,
                 takerAddress,
                 rightOrder.feeRecipientAddress,
                 matchedFillResults.right.takerFeePaid
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/MixinSignatureValidator.sol b/packages/contracts/src/2.0.0/protocol/Exchange/MixinSignatureValidator.sol
index cbb55bfce..29172057a 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/MixinSignatureValidator.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/MixinSignatureValidator.sol
@@ -19,23 +19,17 @@
 pragma solidity ^0.4.24;
 
 import "../../utils/LibBytes/LibBytes.sol";
-import "./libs/LibExchangeErrors.sol";
 import "./mixins/MSignatureValidator.sol";
 import "./mixins/MTransactions.sol";
 import "./interfaces/IWallet.sol";
 import "./interfaces/IValidator.sol";
 
 contract MixinSignatureValidator is
-    LibExchangeErrors,
     MSignatureValidator,
     MTransactions
 {
     using LibBytes for bytes;
     
-    // Personal message headers
-    string constant ETH_PERSONAL_MESSAGE = "\x19Ethereum Signed Message:\n32";
-    string constant TREZOR_PERSONAL_MESSAGE = "\x19Ethereum Signed Message:\n\x20";
-
     // Mapping of hash => signer => signed
     mapping (bytes32 => mapping (address => bool)) public preSigned;
 
@@ -59,7 +53,7 @@ contract MixinSignatureValidator is
                 signerAddress,
                 signature
             ),
-            INVALID_SIGNATURE
+            "INVALID_SIGNATURE"
         );
         preSigned[hash][signerAddress] = true;
     }
@@ -99,14 +93,14 @@ contract MixinSignatureValidator is
         // 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
+            "LENGTH_GREATER_THAN_0_REQUIRED"
         );
 
         // Ensure signature is supported
         uint8 signatureTypeRaw = uint8(signature.popLastByte());
         require(
             signatureTypeRaw < uint8(SignatureType.NSignatureTypes),
-            SIGNATURE_UNSUPPORTED
+            "SIGNATURE_UNSUPPORTED"
         );
 
         // Pop last byte off of signature byte array.
@@ -124,7 +118,7 @@ contract MixinSignatureValidator is
         // it an explicit option. This aids testing and analysis. It is
         // also the initialization value for the enum type.
         if (signatureType == SignatureType.Illegal) {
-            revert(SIGNATURE_ILLEGAL);
+            revert("SIGNATURE_ILLEGAL");
 
         // Always invalid signature.
         // Like Illegal, this is always implicitly available and therefore
@@ -133,7 +127,7 @@ contract MixinSignatureValidator is
         } else if (signatureType == SignatureType.Invalid) {
             require(
                 signature.length == 0,
-                LENGTH_0_REQUIRED
+                "LENGTH_0_REQUIRED"
             );
             isValid = false;
             return isValid;
@@ -142,7 +136,7 @@ contract MixinSignatureValidator is
         } else if (signatureType == SignatureType.EIP712) {
             require(
                 signature.length == 65,
-                LENGTH_65_REQUIRED
+                "LENGTH_65_REQUIRED"
             );
             v = uint8(signature[0]);
             r = signature.readBytes32(1);
@@ -155,13 +149,16 @@ contract MixinSignatureValidator is
         } else if (signatureType == SignatureType.EthSign) {
             require(
                 signature.length == 65,
-                LENGTH_65_REQUIRED
+                "LENGTH_65_REQUIRED"
             );
             v = uint8(signature[0]);
             r = signature.readBytes32(1);
             s = signature.readBytes32(33);
             recovered = ecrecover(
-                keccak256(abi.encodePacked(ETH_PERSONAL_MESSAGE, hash)),
+                keccak256(abi.encodePacked(
+                    "\x19Ethereum Signed Message:\n32",
+                    hash
+                )),
                 v,
                 r,
                 s
@@ -180,7 +177,7 @@ contract MixinSignatureValidator is
         } else if (signatureType == SignatureType.Caller) {
             require(
                 signature.length == 0,
-                LENGTH_0_REQUIRED
+                "LENGTH_0_REQUIRED"
             );
             isValid = signerAddress == msg.sender;
             return isValid;
@@ -230,13 +227,16 @@ contract MixinSignatureValidator is
         } else if (signatureType == SignatureType.Trezor) {
             require(
                 signature.length == 65,
-                LENGTH_65_REQUIRED
+                "LENGTH_65_REQUIRED"
             );
             v = uint8(signature[0]);
             r = signature.readBytes32(1);
             s = signature.readBytes32(33);
             recovered = ecrecover(
-                keccak256(abi.encodePacked(TREZOR_PERSONAL_MESSAGE, hash)),
+                keccak256(abi.encodePacked(
+                    "\x19Ethereum Signed Message:\n\x20",
+                    hash
+                )),
                 v,
                 r,
                 s
@@ -250,6 +250,6 @@ contract MixinSignatureValidator is
         // that we currently support. In this case returning false
         // may lead the caller to incorrectly believe that the
         // signature was invalid.)
-        revert(SIGNATURE_UNSUPPORTED);
+        revert("SIGNATURE_UNSUPPORTED");
     }
 }
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/MixinTransactions.sol b/packages/contracts/src/2.0.0/protocol/Exchange/MixinTransactions.sol
index 20a4a12df..31f7f2847 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/MixinTransactions.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/MixinTransactions.sol
@@ -20,12 +20,10 @@ pragma solidity ^0.4.24;
 import "./libs/LibExchangeErrors.sol";
 import "./mixins/MSignatureValidator.sol";
 import "./mixins/MTransactions.sol";
-import "./libs/LibExchangeErrors.sol";
 import "./libs/LibEIP712.sol";
 
 contract MixinTransactions is
     LibEIP712,
-    LibExchangeErrors,
     MSignatureValidator,
     MTransactions
 {
@@ -62,6 +60,13 @@ contract MixinTransactions is
     {
         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)
@@ -90,7 +95,7 @@ contract MixinTransactions is
         // Prevent reentrancy
         require(
             currentContextAddress == address(0),
-            REENTRANCY_ILLEGAL
+            "REENTRANCY_ILLEGAL"
         );
 
         bytes32 transactionHash = hashEIP712Message(hashZeroExTransaction(
@@ -102,7 +107,7 @@ contract MixinTransactions is
         // Validate transaction has not been executed
         require(
             !transactions[transactionHash],
-            INVALID_TX_HASH
+            "INVALID_TX_HASH"
         );
 
         // Transaction always valid if signer is sender of transaction
@@ -114,7 +119,7 @@ contract MixinTransactions is
                     signerAddress,
                     signature
                 ),
-                INVALID_TX_SIGNATURE
+                "INVALID_TX_SIGNATURE"
             );
 
             // Set the current transaction signer
@@ -125,7 +130,7 @@ contract MixinTransactions is
         transactions[transactionHash] = true;
         require(
             address(this).delegatecall(data),
-            FAILED_EXECUTION
+            "FAILED_EXECUTION"
         );
 
         // Reset current transaction signer
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/MixinWrapperFunctions.sol b/packages/contracts/src/2.0.0/protocol/Exchange/MixinWrapperFunctions.sol
index 724f95518..00668ca43 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/MixinWrapperFunctions.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/MixinWrapperFunctions.sol
@@ -22,13 +22,11 @@ pragma experimental ABIEncoderV2;
 import "./libs/LibMath.sol";
 import "./libs/LibOrder.sol";
 import "./libs/LibFillResults.sol";
-import "./libs/LibExchangeErrors.sol";
 import "./mixins/MExchangeCore.sol";
 
 contract MixinWrapperFunctions is
     LibMath,
     LibFillResults,
-    LibExchangeErrors,
     MExchangeCore
 {
     /// @dev Fills the input order. Reverts if exact takerAssetFillAmount not filled.
@@ -50,7 +48,7 @@ contract MixinWrapperFunctions is
         );
         require(
             fillResults.takerAssetFilledAmount == takerAssetFillAmount,
-            COMPLETE_FILL_FAILED
+            "COMPLETE_FILL_FAILED"
         );
         return fillResults;
     }
@@ -366,14 +364,6 @@ contract MixinWrapperFunctions is
                 signatures[i]
             );
 
-            // HACK: the proxyId is "popped" from the byte array before a fill is settled
-            // by subtracting from the length of the array. Since the popped byte is 
-            // still in memory, we can "unpop" it by incrementing the length of the byte array.
-            assembly {
-                let len := mload(takerAssetData)
-                mstore(takerAssetData, add(len, 1))
-            }
-
             // Update amounts filled and fees paid by maker and taker
             addFillResults(totalFillResults, singleFillResults);
 
@@ -467,14 +457,6 @@ contract MixinWrapperFunctions is
                 signatures[i]
             );
 
-            // HACK: the proxyId is "popped" from the byte array before a fill is settled
-            // by subtracting from the length of the array. Since the popped byte is 
-            // still in memory, we can "unpop" it by incrementing the length of the byte array.
-            assembly {
-                let len := mload(makerAssetData)
-                mstore(makerAssetData, add(len, 1))
-            }
-
             // Update amounts filled and fees paid by maker and taker
             addFillResults(totalFillResults, singleFillResults);
 
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/interfaces/IAssetProxyDispatcher.sol b/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IAssetProxyDispatcher.sol
index 2c331dc34..66f3b5796 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/interfaces/IAssetProxyDispatcher.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IAssetProxyDispatcher.sol
@@ -20,22 +20,16 @@ pragma solidity ^0.4.24;
 
 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
-    )
+    /// @dev Registers an asset proxy to its asset proxy id.
+    ///      Once an asset proxy is registered, it cannot be unregistered.
+    /// @param assetProxy Address of new asset proxy to register.
+    function registerAssetProxy(address assetProxy)
         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)
+    function getAssetProxy(bytes4 assetProxyId)
         external
         view
         returns (address);
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/interfaces/IExchange.sol b/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IExchange.sol
index 9f21c18d7..9f21c18d7 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/interfaces/IExchange.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IExchange.sol
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/interfaces/IExchangeCore.sol b/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IExchangeCore.sol
index 98222f33f..98222f33f 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/interfaces/IExchangeCore.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IExchangeCore.sol
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/interfaces/IMatchOrders.sol b/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IMatchOrders.sol
index df009d063..df009d063 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/interfaces/IMatchOrders.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IMatchOrders.sol
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/interfaces/ISignatureValidator.sol b/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/ISignatureValidator.sol
index 511463309..511463309 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/interfaces/ISignatureValidator.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/ISignatureValidator.sol
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/interfaces/ITransactions.sol b/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/ITransactions.sol
index a7cab8f55..a7cab8f55 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/interfaces/ITransactions.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/ITransactions.sol
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/interfaces/IValidator.sol b/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IValidator.sol
index 0b1796a66..0b1796a66 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/interfaces/IValidator.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IValidator.sol
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/interfaces/IWallet.sol b/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IWallet.sol
index c86a2c057..c86a2c057 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/interfaces/IWallet.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IWallet.sol
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/interfaces/IWrapperFunctions.sol b/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IWrapperFunctions.sol
index 84bb683bc..84bb683bc 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/interfaces/IWrapperFunctions.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/interfaces/IWrapperFunctions.sol
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/libs/LibConstants.sol b/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibConstants.sol
index 4a9452448..488ca956c 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/libs/LibConstants.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibConstants.sol
@@ -25,9 +25,6 @@ contract LibConstants {
     //        not constant to make testing easier.
     bytes public ZRX_ASSET_DATA;
 
-    // Proxy Id for ZRX token.
-    uint8 constant ZRX_PROXY_ID = 1;
-
     // @TODO: Remove when we deploy.
     constructor (bytes memory zrxAssetData)
         public
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/libs/LibEIP712.sol b/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibEIP712.sol
index b983347a4..b983347a4 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/libs/LibEIP712.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibEIP712.sol
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/libs/LibExchangeErrors.sol b/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibExchangeErrors.sol
index a43f0f927..01aa78a1d 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/libs/LibExchangeErrors.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibExchangeErrors.sol
@@ -18,7 +18,10 @@
 
 pragma solidity ^0.4.24;
 
+/// @dev This contract documents the revert reasons used in the Exchange contract.
+/// This contract is intended to serve as a reference, but is not actually used for efficiency reasons.
 contract LibExchangeErrors {
+
     /// Order validation errors ///
     string constant ORDER_UNFILLABLE = "ORDER_UNFILLABLE";                              // Order cannot be filled.
     string constant INVALID_MAKER = "INVALID_MAKER";                                    // Invalid makerAddress.
@@ -51,14 +54,15 @@ contract LibExchangeErrors {
     string constant FAILED_EXECUTION = "FAILED_EXECUTION";                              // Transaction execution failed. 
     
     /// registerAssetProxy errors ///
-    string constant ASSET_PROXY_MISMATCH = "ASSET_PROXY_MISMATCH";                      // oldAssetProxy proxy does not match currentAssetProxy. 
-    string constant ASSET_PROXY_ID_MISMATCH = "ASSET_PROXY_ID_MISMATCH";                // newAssetProxyId does not match given assetProxyId.
+    string constant ASSET_PROXY_ALREADY_EXISTS = "ASSET_PROXY_ALREADY_EXISTS";          // AssetProxy with same id already exists.
 
     /// dispatchTransferFrom errors ///
     string constant ASSET_PROXY_DOES_NOT_EXIST = "ASSET_PROXY_DOES_NOT_EXIST";          // No assetProxy registered at given id.
+    string constant TRANSFER_FAILED = "TRANSFER_FAILED";                                // Asset transfer unsuccesful.
 
     /// Length validation errors ///
     string constant LENGTH_GREATER_THAN_0_REQUIRED = "LENGTH_GREATER_THAN_0_REQUIRED";  // Byte array must have a length greater than 0.
+    string constant LENGTH_GREATER_THAN_3_REQUIRED = "LENGTH_GREATER_THAN_3_REQUIRED";  // Byte array must have a length greater than 3.
     string constant LENGTH_0_REQUIRED = "LENGTH_0_REQUIRED";                            // Byte array must have a length of 0.
     string constant LENGTH_65_REQUIRED = "LENGTH_65_REQUIRED";                          // Byte array must have a length of 65.
 }
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/libs/LibFillResults.sol b/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibFillResults.sol
index 63f1b8c87..63f1b8c87 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/libs/LibFillResults.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibFillResults.sol
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/libs/LibMath.sol b/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibMath.sol
index 233547b9f..bfe2fd33f 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/libs/LibMath.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibMath.sol
@@ -23,7 +23,6 @@ import "../../../utils/SafeMath/SafeMath.sol";
 contract LibMath is
     SafeMath
 {
-    string constant ROUNDING_ERROR_ON_PARTIAL_AMOUNT = "A rounding error occurred when calculating partial transfer amounts.";
 
     /// @dev Calculates partial value given a numerator and denominator.
     /// @param numerator Numerator.
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/libs/LibOrder.sol b/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibOrder.sol
index f3f1e9277..954f94f76 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/libs/LibOrder.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/libs/LibOrder.sol
@@ -98,6 +98,21 @@ 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)
+        //   ));
         assembly {
             // Backup
             let temp1 := mload(sub(order,  32))
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/mixins/MAssetProxyDispatcher.sol b/packages/contracts/src/2.0.0/protocol/Exchange/mixins/MAssetProxyDispatcher.sol
index 788f42c60..5bf59c6ce 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/mixins/MAssetProxyDispatcher.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/mixins/MAssetProxyDispatcher.sol
@@ -26,21 +26,18 @@ contract MAssetProxyDispatcher is
 {
 
     // Logs registration of new asset proxy
-    event AssetProxySet(
-        uint8 id,               // Id of new registered AssetProxy.
-        address newAssetProxy,  // Address of new registered AssetProxy.
-        address oldAssetProxy   // Address of AssetProxy that was overwritten at given id (or null address).
+    event AssetProxyRegistered(
+        bytes4 id,              // Id of new registered AssetProxy.
+        address assetProxy      // Address of new registered AssetProxy.
     );
 
     /// @dev Forwards arguments to assetProxy and calls `transferFrom`. Either succeeds or throws.
-    /// @param assetData Byte array encoded for the respective asset proxy.
-    /// @param assetProxyId Id of assetProxy to dispach to.
+    /// @param assetData Byte array encoded for the asset.
     /// @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 assetData,
-        uint8 assetProxyId,
         address from,
         address to,
         uint256 amount
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/mixins/MExchangeCore.sol b/packages/contracts/src/2.0.0/protocol/Exchange/mixins/MExchangeCore.sol
index 6e406e1c4..6e406e1c4 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/mixins/MExchangeCore.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/mixins/MExchangeCore.sol
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/mixins/MMatchOrders.sol b/packages/contracts/src/2.0.0/protocol/Exchange/mixins/MMatchOrders.sol
index abe7c3596..abe7c3596 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/mixins/MMatchOrders.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/mixins/MMatchOrders.sol
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/mixins/MSignatureValidator.sol b/packages/contracts/src/2.0.0/protocol/Exchange/mixins/MSignatureValidator.sol
index 6cc1d7a10..6cc1d7a10 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/mixins/MSignatureValidator.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/mixins/MSignatureValidator.sol
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/mixins/MTransactions.sol b/packages/contracts/src/2.0.0/protocol/Exchange/mixins/MTransactions.sol
index e2f89de01..e2f89de01 100644
--- a/packages/contracts/src/contracts/current/protocol/Exchange/mixins/MTransactions.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/mixins/MTransactions.sol
diff --git a/packages/contracts/src/contracts/current/test/DummyERC20Token/DummyERC20Token.sol b/packages/contracts/src/2.0.0/test/DummyERC20Token/DummyERC20Token.sol
index b2fe2df06..b2fe2df06 100644
--- a/packages/contracts/src/contracts/current/test/DummyERC20Token/DummyERC20Token.sol
+++ b/packages/contracts/src/2.0.0/test/DummyERC20Token/DummyERC20Token.sol
diff --git a/packages/contracts/src/contracts/current/test/DummyERC721Receiver/DummyERC721Receiver.sol b/packages/contracts/src/2.0.0/test/DummyERC721Receiver/DummyERC721Receiver.sol
index c584d0b54..c584d0b54 100644
--- a/packages/contracts/src/contracts/current/test/DummyERC721Receiver/DummyERC721Receiver.sol
+++ b/packages/contracts/src/2.0.0/test/DummyERC721Receiver/DummyERC721Receiver.sol
diff --git a/packages/contracts/src/contracts/current/test/DummyERC721Token/DummyERC721Token.sol b/packages/contracts/src/2.0.0/test/DummyERC721Token/DummyERC721Token.sol
index 5503eb2f2..78ea96447 100644
--- a/packages/contracts/src/contracts/current/test/DummyERC721Token/DummyERC721Token.sol
+++ b/packages/contracts/src/2.0.0/test/DummyERC721Token/DummyERC721Token.sol
@@ -56,4 +56,20 @@ contract DummyERC721Token is
         );
         _mint(to, tokenId);
     }
+
+    /**
+    * @dev Function to burn a token
+    * @dev Reverts if the given token ID doesn't exist
+    * @param tokenId uint256 ID of the token to be minted by the msg.sender
+    */
+    function burn(address owner, uint256 tokenId)
+        public
+        onlyOwner
+    {
+        require(
+            exists(tokenId),
+            "Token with tokenId does not exist."
+        );
+        _burn(owner, tokenId);
+    }
 }
diff --git a/packages/contracts/src/contracts/current/test/ExchangeWrapper/ExchangeWrapper.sol b/packages/contracts/src/2.0.0/test/ExchangeWrapper/ExchangeWrapper.sol
index 5baaf6e5a..5baaf6e5a 100644
--- a/packages/contracts/src/contracts/current/test/ExchangeWrapper/ExchangeWrapper.sol
+++ b/packages/contracts/src/2.0.0/test/ExchangeWrapper/ExchangeWrapper.sol
diff --git a/packages/contracts/src/contracts/current/test/Mintable/Mintable.sol b/packages/contracts/src/2.0.0/test/Mintable/Mintable.sol
index a91bfee9e..a91bfee9e 100644
--- a/packages/contracts/src/contracts/current/test/Mintable/Mintable.sol
+++ b/packages/contracts/src/2.0.0/test/Mintable/Mintable.sol
diff --git a/packages/contracts/src/contracts/current/test/TestAssetProxyDispatcher/TestAssetProxyDispatcher.sol b/packages/contracts/src/2.0.0/test/TestAssetProxyDispatcher/TestAssetProxyDispatcher.sol
index d469a07f0..2ae69e0ef 100644
--- a/packages/contracts/src/contracts/current/test/TestAssetProxyDispatcher/TestAssetProxyDispatcher.sol
+++ b/packages/contracts/src/2.0.0/test/TestAssetProxyDispatcher/TestAssetProxyDispatcher.sol
@@ -24,12 +24,11 @@ import "../../protocol/Exchange/MixinAssetProxyDispatcher.sol";
 contract TestAssetProxyDispatcher is MixinAssetProxyDispatcher {
     function publicDispatchTransferFrom(
         bytes memory assetData,
-        uint8 assetProxyId,
         address from,
         address to,
         uint256 amount)
         public
     {
-        dispatchTransferFrom(assetData, assetProxyId, from, to, amount);
+        dispatchTransferFrom(assetData, from, to, amount);
     }
 }
diff --git a/packages/contracts/src/contracts/current/test/TestAssetProxyOwner/TestAssetProxyOwner.sol b/packages/contracts/src/2.0.0/test/TestAssetProxyOwner/TestAssetProxyOwner.sol
index 2abcd17a0..2abcd17a0 100644
--- a/packages/contracts/src/contracts/current/test/TestAssetProxyOwner/TestAssetProxyOwner.sol
+++ b/packages/contracts/src/2.0.0/test/TestAssetProxyOwner/TestAssetProxyOwner.sol
diff --git a/packages/contracts/src/contracts/current/test/TestLibBytes/TestLibBytes.sol b/packages/contracts/src/2.0.0/test/TestLibBytes/TestLibBytes.sol
index f45faaf36..f45faaf36 100644
--- a/packages/contracts/src/contracts/current/test/TestLibBytes/TestLibBytes.sol
+++ b/packages/contracts/src/2.0.0/test/TestLibBytes/TestLibBytes.sol
diff --git a/packages/contracts/src/contracts/current/test/TestLibs/TestLibs.sol b/packages/contracts/src/2.0.0/test/TestLibs/TestLibs.sol
index 010080703..010080703 100644
--- a/packages/contracts/src/contracts/current/test/TestLibs/TestLibs.sol
+++ b/packages/contracts/src/2.0.0/test/TestLibs/TestLibs.sol
diff --git a/packages/contracts/src/contracts/current/test/TestSignatureValidator/TestSignatureValidator.sol b/packages/contracts/src/2.0.0/test/TestSignatureValidator/TestSignatureValidator.sol
index 0f84678cf..0f84678cf 100644
--- a/packages/contracts/src/contracts/current/test/TestSignatureValidator/TestSignatureValidator.sol
+++ b/packages/contracts/src/2.0.0/test/TestSignatureValidator/TestSignatureValidator.sol
diff --git a/packages/contracts/src/contracts/current/test/TestValidator/TestValidator.sol b/packages/contracts/src/2.0.0/test/TestValidator/TestValidator.sol
index f9271bf7a..f9271bf7a 100644
--- a/packages/contracts/src/contracts/current/test/TestValidator/TestValidator.sol
+++ b/packages/contracts/src/2.0.0/test/TestValidator/TestValidator.sol
diff --git a/packages/contracts/src/contracts/current/test/TestWallet/TestWallet.sol b/packages/contracts/src/2.0.0/test/TestWallet/TestWallet.sol
index 17dee9e9c..17dee9e9c 100644
--- a/packages/contracts/src/contracts/current/test/TestWallet/TestWallet.sol
+++ b/packages/contracts/src/2.0.0/test/TestWallet/TestWallet.sol
diff --git a/packages/contracts/src/contracts/current/test/Whitelist/Whitelist.sol b/packages/contracts/src/2.0.0/test/Whitelist/Whitelist.sol
index d35815474..8b52858b1 100644
--- a/packages/contracts/src/contracts/current/test/Whitelist/Whitelist.sol
+++ b/packages/contracts/src/2.0.0/test/Whitelist/Whitelist.sol
@@ -23,13 +23,13 @@ import "../../protocol/Exchange/interfaces/IExchange.sol";
 import "../../protocol/Exchange/libs/LibOrder.sol";
 import "../../utils/Ownable/Ownable.sol";
 
-contract Whitelist is 
+contract Whitelist is
     Ownable
 {
     // Revert reasons
-    string constant MAKER_NOT_WHITELISTED = "Maker address not whitelisted.";
-    string constant TAKER_NOT_WHITELISTED = "Taker address not whitelisted.";
-    string constant INVALID_SENDER = "Sender must equal transaction origin.";
+    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;
@@ -77,7 +77,7 @@ contract Whitelist is
         public
     {
         address takerAddress = msg.sender;
-    
+
         // This contract must be the entry point for the transaction.
         require(
             takerAddress == tx.origin,
diff --git a/packages/contracts/src/contracts/current/tokens/ERC20Token/ERC20Token.sol b/packages/contracts/src/2.0.0/tokens/ERC20Token/ERC20Token.sol
index f0bcdafef..b6961a6ec 100644
--- a/packages/contracts/src/contracts/current/tokens/ERC20Token/ERC20Token.sol
+++ b/packages/contracts/src/2.0.0/tokens/ERC20Token/ERC20Token.sol
@@ -23,8 +23,8 @@ import "./IERC20Token.sol";
 
 contract ERC20Token is IERC20Token {
 
-    string constant INSUFFICIENT_BALANCE = "Insufficient balance to complete transfer.";
-    string constant INSUFFICIENT_ALLOWANCE = "Insufficient allowance to complete transfer.";
+    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;
@@ -97,4 +97,3 @@ contract ERC20Token is IERC20Token {
         return allowed[_owner][_spender];
     }
 }
-
diff --git a/packages/contracts/src/contracts/current/tokens/ERC20Token/IERC20Token.sol b/packages/contracts/src/2.0.0/tokens/ERC20Token/IERC20Token.sol
index eb879b6a8..eb879b6a8 100644
--- a/packages/contracts/src/contracts/current/tokens/ERC20Token/IERC20Token.sol
+++ b/packages/contracts/src/2.0.0/tokens/ERC20Token/IERC20Token.sol
diff --git a/packages/contracts/src/contracts/current/tokens/ERC721Token/ERC721Token.sol b/packages/contracts/src/2.0.0/tokens/ERC721Token/ERC721Token.sol
index 41ba149e3..41ba149e3 100644
--- a/packages/contracts/src/contracts/current/tokens/ERC721Token/ERC721Token.sol
+++ b/packages/contracts/src/2.0.0/tokens/ERC721Token/ERC721Token.sol
diff --git a/packages/contracts/src/contracts/current/tokens/ERC721Token/IERC721Receiver.sol b/packages/contracts/src/2.0.0/tokens/ERC721Token/IERC721Receiver.sol
index b0fff3c90..b0fff3c90 100644
--- a/packages/contracts/src/contracts/current/tokens/ERC721Token/IERC721Receiver.sol
+++ b/packages/contracts/src/2.0.0/tokens/ERC721Token/IERC721Receiver.sol
diff --git a/packages/contracts/src/contracts/current/tokens/ERC721Token/IERC721Token.sol b/packages/contracts/src/2.0.0/tokens/ERC721Token/IERC721Token.sol
index 345712d67..345712d67 100644
--- a/packages/contracts/src/contracts/current/tokens/ERC721Token/IERC721Token.sol
+++ b/packages/contracts/src/2.0.0/tokens/ERC721Token/IERC721Token.sol
diff --git a/packages/contracts/src/contracts/current/tokens/UnlimitedAllowanceToken/UnlimitedAllowanceToken.sol b/packages/contracts/src/2.0.0/tokens/UnlimitedAllowanceToken/UnlimitedAllowanceToken.sol
index f62602ab3..f62602ab3 100644
--- a/packages/contracts/src/contracts/current/tokens/UnlimitedAllowanceToken/UnlimitedAllowanceToken.sol
+++ b/packages/contracts/src/2.0.0/tokens/UnlimitedAllowanceToken/UnlimitedAllowanceToken.sol
diff --git a/packages/contracts/src/contracts/current/tokens/WETH9/WETH9.sol b/packages/contracts/src/2.0.0/tokens/WETH9/WETH9.sol
index 733ca414b..733ca414b 100644
--- a/packages/contracts/src/contracts/current/tokens/WETH9/WETH9.sol
+++ b/packages/contracts/src/2.0.0/tokens/WETH9/WETH9.sol
diff --git a/packages/contracts/src/contracts/current/tokens/ZRXToken/ZRXToken.sol b/packages/contracts/src/2.0.0/tokens/ZRXToken/ZRXToken.sol
index 2d8e74f2c..2e5b61e0b 100644
--- a/packages/contracts/src/contracts/current/tokens/ZRXToken/ZRXToken.sol
+++ b/packages/contracts/src/2.0.0/tokens/ZRXToken/ZRXToken.sol
@@ -18,7 +18,7 @@
 
 pragma solidity ^0.4.11;
 
-import { UnlimitedAllowanceToken_v1 as UnlimitedAllowanceToken } from "../../../previous/UnlimitedAllowanceToken/UnlimitedAllowanceToken_v1.sol";
+import { UnlimitedAllowanceToken_v1 as UnlimitedAllowanceToken } from "../../../1.0.0/UnlimitedAllowanceToken/UnlimitedAllowanceToken_v1.sol";
 
 contract ZRXToken is UnlimitedAllowanceToken {
 
diff --git a/packages/contracts/src/contracts/current/utils/LibBytes/LibBytes.sol b/packages/contracts/src/2.0.0/utils/LibBytes/LibBytes.sol
index e4cbf318b..78b1ddf7c 100644
--- a/packages/contracts/src/contracts/current/utils/LibBytes/LibBytes.sol
+++ b/packages/contracts/src/2.0.0/utils/LibBytes/LibBytes.sol
@@ -19,17 +19,8 @@
 pragma solidity ^0.4.24;
 
 library LibBytes {
-    using LibBytes for bytes;
 
-    // Revert reasons
-    string constant GREATER_THAN_ZERO_LENGTH_REQUIRED = "GREATER_THAN_ZERO_LENGTH_REQUIRED";
-    string constant GREATER_OR_EQUAL_TO_4_LENGTH_REQUIRED = "GREATER_OR_EQUAL_TO_4_LENGTH_REQUIRED";
-    string constant GREATER_OR_EQUAL_TO_20_LENGTH_REQUIRED = "GREATER_OR_EQUAL_TO_20_LENGTH_REQUIRED";
-    string constant GREATER_OR_EQUAL_TO_32_LENGTH_REQUIRED = "GREATER_OR_EQUAL_TO_32_LENGTH_REQUIRED";
-    string constant GREATER_OR_EQUAL_TO_NESTED_BYTES_LENGTH_REQUIRED = "GREATER_OR_EQUAL_TO_NESTED_BYTES_LENGTH_REQUIRED";
-    string constant GREATER_OR_EQUAL_TO_SOURCE_BYTES_LENGTH_REQUIRED = "GREATER_OR_EQUAL_TO_SOURCE_BYTES_LENGTH_REQUIRED";
-    string constant FROM_LESS_THAN_TO_REQUIRED = "FROM_LESS_THAN_TO_REQUIRED";
-    string constant TO_LESS_THAN_LENGTH_REQUIRED = "TO_LESS_THAN_LENGTH_REQUIRED";
+    using LibBytes for bytes;
 
     /// @dev Gets the memory address for a byte array.
     /// @param input Byte array to lookup.
@@ -176,8 +167,14 @@ library LibBytes {
         pure
         returns (bytes memory result)
     {
-        require(from <= to, FROM_LESS_THAN_TO_REQUIRED);
-        require(to < b.length, TO_LESS_THAN_LENGTH_REQUIRED);
+        require(
+            from <= to,
+            "FROM_LESS_THAN_TO_REQUIRED"
+        );
+        require(
+            to < b.length,
+            "TO_LESS_THAN_LENGTH_REQUIRED"
+        );
         
         // Create a new bytes structure and copy contents
         result = new bytes(to - from);
@@ -199,8 +196,14 @@ library LibBytes {
         pure
         returns (bytes memory result)
     {
-        require(from <= to, FROM_LESS_THAN_TO_REQUIRED);
-        require(to < b.length, TO_LESS_THAN_LENGTH_REQUIRED);
+        require(
+            from <= to,
+            "FROM_LESS_THAN_TO_REQUIRED"
+        );
+        require(
+            to < b.length,
+            "TO_LESS_THAN_LENGTH_REQUIRED"
+        );
         
         // Create a new bytes structure around [from, to) in-place.
         assembly {
@@ -220,7 +223,7 @@ library LibBytes {
     {
         require(
             b.length > 0,
-            GREATER_THAN_ZERO_LENGTH_REQUIRED
+            "GREATER_THAN_ZERO_LENGTH_REQUIRED"
         );
 
         // Store last byte.
@@ -244,7 +247,7 @@ library LibBytes {
     {
         require(
             b.length >= 20,
-            GREATER_OR_EQUAL_TO_20_LENGTH_REQUIRED
+            "GREATER_OR_EQUAL_TO_20_LENGTH_REQUIRED"
         );
 
         // Store last 20 bytes.
@@ -290,7 +293,7 @@ library LibBytes {
     {
         require(
             b.length >= index + 20,  // 20 is length of address
-            GREATER_OR_EQUAL_TO_20_LENGTH_REQUIRED
+            "GREATER_OR_EQUAL_TO_20_LENGTH_REQUIRED"
         );
 
         // Add offset to index:
@@ -322,7 +325,7 @@ library LibBytes {
     {
         require(
             b.length >= index + 20,  // 20 is length of address
-            GREATER_OR_EQUAL_TO_20_LENGTH_REQUIRED
+            "GREATER_OR_EQUAL_TO_20_LENGTH_REQUIRED"
         );
 
         // Add offset to index:
@@ -365,7 +368,7 @@ library LibBytes {
     {
         require(
             b.length >= index + 32,
-            GREATER_OR_EQUAL_TO_32_LENGTH_REQUIRED
+            "GREATER_OR_EQUAL_TO_32_LENGTH_REQUIRED"
         );
 
         // Arrays are prefixed by a 256 bit length parameter
@@ -392,7 +395,7 @@ library LibBytes {
     {
         require(
             b.length >= index + 32,
-            GREATER_OR_EQUAL_TO_32_LENGTH_REQUIRED
+            "GREATER_OR_EQUAL_TO_32_LENGTH_REQUIRED"
         );
 
         // Arrays are prefixed by a 256 bit length parameter
@@ -447,7 +450,7 @@ library LibBytes {
     {
         require(
             b.length >= index + 4,
-            GREATER_OR_EQUAL_TO_4_LENGTH_REQUIRED
+            "GREATER_OR_EQUAL_TO_4_LENGTH_REQUIRED"
         );
         assembly {
             result := mload(add(b, 32))
@@ -459,6 +462,8 @@ library LibBytes {
     }
 
     /// @dev Reads nested bytes from a specific position.
+    /// @dev NOTE: the returned value overlaps with the input value.
+    ///            Both should be treated as immutable.
     /// @param b Byte array containing nested bytes.
     /// @param index Index of nested bytes.
     /// @return result Nested bytes.
@@ -478,17 +483,13 @@ library LibBytes {
         // length of nested bytes
         require(
             b.length >= index + nestedBytesLength,
-            GREATER_OR_EQUAL_TO_NESTED_BYTES_LENGTH_REQUIRED
+            "GREATER_OR_EQUAL_TO_NESTED_BYTES_LENGTH_REQUIRED"
         );
-
-        // Allocate memory and copy value to result
-        result = new bytes(nestedBytesLength);
-        memCopy(
-            result.contentAddress(),
-            b.contentAddress() + index,
-            nestedBytesLength
-        );
-
+        
+        // Return a pointer to the byte array as it exists inside `b`
+        assembly {
+            result := add(b, index)
+        }
         return result;
     }
 
@@ -508,7 +509,7 @@ library LibBytes {
         // length of input
         require(
             b.length >= index + 32 /* 32 bytes to store length */ + input.length,
-            GREATER_OR_EQUAL_TO_NESTED_BYTES_LENGTH_REQUIRED
+            "GREATER_OR_EQUAL_TO_NESTED_BYTES_LENGTH_REQUIRED"
         );
 
         // Copy <input> into <b>
@@ -533,7 +534,7 @@ library LibBytes {
         // Dest length must be >= source length, or some bytes would not be copied.
         require(
             dest.length >= sourceLen,
-            GREATER_OR_EQUAL_TO_SOURCE_BYTES_LENGTH_REQUIRED
+            "GREATER_OR_EQUAL_TO_SOURCE_BYTES_LENGTH_REQUIRED"
         );
         memCopy(
             dest.contentAddress(),
diff --git a/packages/contracts/src/contracts/current/utils/Ownable/IOwnable.sol b/packages/contracts/src/2.0.0/utils/Ownable/IOwnable.sol
index e77680903..e77680903 100644
--- a/packages/contracts/src/contracts/current/utils/Ownable/IOwnable.sol
+++ b/packages/contracts/src/2.0.0/utils/Ownable/IOwnable.sol
diff --git a/packages/contracts/src/contracts/current/utils/Ownable/Ownable.sol b/packages/contracts/src/2.0.0/utils/Ownable/Ownable.sol
index 99b93d0d2..6f5761cc7 100644
--- a/packages/contracts/src/contracts/current/utils/Ownable/Ownable.sol
+++ b/packages/contracts/src/2.0.0/utils/Ownable/Ownable.sol
@@ -13,9 +13,6 @@ import "./IOwnable.sol";
 contract Ownable is IOwnable {
     address public owner;
 
-    // Revert reasons
-    string constant ONLY_CONTRACT_OWNER = "ONLY_CONTRACT_OWNER";
-
     constructor ()
         public
     {
@@ -25,7 +22,7 @@ contract Ownable is IOwnable {
     modifier onlyOwner() {
         require(
             msg.sender == owner,
-            ONLY_CONTRACT_OWNER
+            "ONLY_CONTRACT_OWNER"
         );
         _;
     }
diff --git a/packages/contracts/src/contracts/current/utils/SafeMath/SafeMath.sol b/packages/contracts/src/2.0.0/utils/SafeMath/SafeMath.sol
index e137f6ca5..e137f6ca5 100644
--- a/packages/contracts/src/contracts/current/utils/SafeMath/SafeMath.sol
+++ b/packages/contracts/src/2.0.0/utils/SafeMath/SafeMath.sol
diff --git a/packages/contracts/src/contracts/current/protocol/AssetProxy/ERC20Proxy.sol b/packages/contracts/src/contracts/current/protocol/AssetProxy/ERC20Proxy.sol
deleted file mode 100644
index 7ca823d1f..000000000
--- a/packages/contracts/src/contracts/current/protocol/AssetProxy/ERC20Proxy.sol
+++ /dev/null
@@ -1,44 +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 "./MixinAssetProxy.sol";
-import "./MixinAuthorizable.sol";
-import "./MixinERC20Transfer.sol";
-
-contract ERC20Proxy is
-    MixinAssetProxy,
-    MixinAuthorizable,
-    MixinERC20Transfer
-{
-    // Id of this proxy.
-    uint8 constant PROXY_ID = 1;
-
-    /// @dev Gets the proxy id associated with the proxy address.
-    /// @return Proxy id.
-    function getProxyId()
-        external
-        view
-        returns (uint8)
-    {
-        return PROXY_ID;
-    }
-}
diff --git a/packages/contracts/src/contracts/current/protocol/AssetProxy/ERC721Proxy.sol b/packages/contracts/src/contracts/current/protocol/AssetProxy/ERC721Proxy.sol
deleted file mode 100644
index 7ff25aea3..000000000
--- a/packages/contracts/src/contracts/current/protocol/AssetProxy/ERC721Proxy.sol
+++ /dev/null
@@ -1,44 +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 "./MixinAssetProxy.sol";
-import "./MixinAuthorizable.sol";
-import "./MixinERC721Transfer.sol";
-
-contract ERC721Proxy is
-    MixinAssetProxy,
-    MixinAuthorizable,
-    MixinERC721Transfer
-{
-    // Id of this proxy.
-    uint8 constant PROXY_ID = 2;
-
-    /// @dev Gets the proxy id associated with the proxy address.
-    /// @return Proxy id.
-    function getProxyId()
-        external
-        view
-        returns (uint8)
-    {
-        return PROXY_ID;
-    }
-}
diff --git a/packages/contracts/src/contracts/current/protocol/AssetProxy/MixinAssetProxy.sol b/packages/contracts/src/contracts/current/protocol/AssetProxy/MixinAssetProxy.sol
deleted file mode 100644
index 9032658e7..000000000
--- a/packages/contracts/src/contracts/current/protocol/AssetProxy/MixinAssetProxy.sol
+++ /dev/null
@@ -1,75 +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 "./mixins/MAuthorizable.sol";
-import "./mixins/MAssetProxy.sol";
-
-contract MixinAssetProxy is
-    MAuthorizable,
-    MAssetProxy
-{
-
-    /// @dev Transfers assets. Either succeeds or throws.
-    /// @param assetData Encoded byte array.
-    /// @param from Address to transfer asset from.
-    /// @param to Address to transfer asset to.
-    /// @param amount Amount of asset to transfer.
-    function transferFrom(
-        bytes assetData,
-        address from,
-        address to,
-        uint256 amount
-    )
-        external
-        onlyAuthorized
-    {
-        transferFromInternal(
-            assetData,
-            from,
-            to,
-            amount
-        );
-    }
-
-    /// @dev Makes multiple transfers of assets. Either succeeds or throws.
-    /// @param assetData Array of byte arrays encoded for the respective asset proxy.
-    /// @param from Array of addresses to transfer assets from.
-    /// @param to Array of addresses to transfer assets to.
-    /// @param amounts Array of amounts of assets to transfer.
-    function batchTransferFrom(
-        bytes[] memory assetData,
-        address[] memory from,
-        address[] memory to,
-        uint256[] memory amounts
-    )
-        public
-        onlyAuthorized
-    {
-        for (uint256 i = 0; i < assetData.length; i++) {
-            transferFromInternal(
-                assetData[i],
-                from[i],
-                to[i],
-                amounts[i]
-            );
-        }
-    }
-}
diff --git a/packages/contracts/src/contracts/current/protocol/AssetProxy/MixinERC20Transfer.sol b/packages/contracts/src/contracts/current/protocol/AssetProxy/MixinERC20Transfer.sol
deleted file mode 100644
index 0e7f3fc89..000000000
--- a/packages/contracts/src/contracts/current/protocol/AssetProxy/MixinERC20Transfer.sol
+++ /dev/null
@@ -1,82 +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/ERC20Token/IERC20Token.sol";
-import "./libs/LibTransferErrors.sol";
-
-contract MixinERC20Transfer is
-    LibTransferErrors
-{
-    using LibBytes for bytes;
-
-    /// @dev Internal version of `transferFrom`.
-    /// @param assetData Encoded byte array.
-    /// @param from Address to transfer asset from.
-    /// @param to Address to transfer asset to.
-    /// @param amount Amount of asset to transfer.
-    function transferFromInternal(
-        bytes memory assetData,
-        address from,
-        address to,
-        uint256 amount
-    )
-        internal
-    {
-        // Decode asset data.
-        address token = assetData.readAddress(0);
-
-        // Transfer tokens.
-        // We do a raw call so we can check the success separate
-        // from the return data.
-        bool success = token.call(abi.encodeWithSelector(
-            IERC20Token(token).transferFrom.selector,
-            from,
-            to,
-            amount
-        ));
-        require(
-            success,
-            TRANSFER_FAILED
-        );
-        
-        // Check return data.
-        // If there is no return data, we assume the token incorrectly
-        // does not return a bool. In this case we expect it to revert
-        // on failure, which was handled above.
-        // If the token does return data, we require that it is a single
-        // value that evaluates to true.
-        assembly {
-            if returndatasize {
-                success := 0
-                if eq(returndatasize, 32) {
-                    // First 64 bytes of memory are reserved scratch space
-                    returndatacopy(0, 0, 32)
-                    success := mload(0)
-                }
-            }
-        }
-        require(
-            success,
-            TRANSFER_FAILED
-        );
-    }
-}
diff --git a/packages/contracts/src/contracts/current/protocol/AssetProxy/MixinERC721Transfer.sol b/packages/contracts/src/contracts/current/protocol/AssetProxy/MixinERC721Transfer.sol
deleted file mode 100644
index 944068bbb..000000000
--- a/packages/contracts/src/contracts/current/protocol/AssetProxy/MixinERC721Transfer.sol
+++ /dev/null
@@ -1,94 +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/ERC721Token.sol";
-import "./libs/LibTransferErrors.sol";
-
-contract MixinERC721Transfer is
-    LibTransferErrors
-{
-    using LibBytes for bytes;
-    
-    /// @dev Internal version of `transferFrom`.
-    /// @param assetData Encoded byte array.
-    /// @param from Address to transfer asset from.
-    /// @param to Address to transfer asset to.
-    /// @param amount Amount of asset to transfer.
-    function transferFromInternal(
-        bytes memory assetData,
-        address from,
-        address to,
-        uint256 amount
-    )
-        internal
-    {
-        // There exists only 1 of each token.
-        require(
-            amount == 1,
-            INVALID_AMOUNT
-        );
-    
-        // Decode asset data.
-        (
-            address token,
-            uint256 tokenId,
-            bytes memory receiverData
-        ) = decodeERC721AssetData(assetData);
-
-        ERC721Token(token).safeTransferFrom(
-            from,
-            to,
-            tokenId,
-            receiverData
-        );
-    }
-
-    /// @dev Decodes ERC721 Asset data.
-    /// @param assetData Encoded byte array.
-    /// @return proxyId Intended ERC721 proxy id.
-    /// @return token ERC721 token address.
-    /// @return tokenId ERC721 token id.
-    /// @return receiverData Additional data with no specific format, which
-    ///                      is passed to the receiving contract's onERC721Received.
-    function decodeERC721AssetData(bytes memory assetData)
-        internal
-        pure
-        returns (
-            address token,
-            uint256 tokenId,
-            bytes memory receiverData
-        )
-    {
-        // Decode asset data.
-        token = assetData.readAddress(0);
-        tokenId = assetData.readUint256(20);
-        if (assetData.length > 52) {
-            receiverData = assetData.readBytesWithLength(52);
-        }
-
-        return (
-            token,
-            tokenId,
-            receiverData
-        );
-    }
-}
diff --git a/packages/contracts/src/contracts/current/protocol/AssetProxy/mixins/MAssetProxy.sol b/packages/contracts/src/contracts/current/protocol/AssetProxy/mixins/MAssetProxy.sol
deleted file mode 100644
index a52cb56f9..000000000
--- a/packages/contracts/src/contracts/current/protocol/AssetProxy/mixins/MAssetProxy.sol
+++ /dev/null
@@ -1,40 +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 "../interfaces/IAssetProxy.sol";
-
-contract MAssetProxy is
-    IAssetProxy
-{
-
-    /// @dev Internal version of `transferFrom`.
-    /// @param assetData Encoded byte array.
-    /// @param from Address to transfer asset from.
-    /// @param to Address to transfer asset to.
-    /// @param amount Amount of asset to transfer.
-    function transferFromInternal(
-        bytes memory assetData,
-        address from,
-        address to,
-        uint256 amount
-    )
-        internal;
-}
diff --git a/packages/contracts/src/contracts/current/protocol/Exchange/MixinAssetProxyDispatcher.sol b/packages/contracts/src/contracts/current/protocol/Exchange/MixinAssetProxyDispatcher.sol
deleted file mode 100644
index b8d6c0722..000000000
--- a/packages/contracts/src/contracts/current/protocol/Exchange/MixinAssetProxyDispatcher.sol
+++ /dev/null
@@ -1,118 +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;
-
-import "../../utils/Ownable/Ownable.sol";
-import "./libs/LibExchangeErrors.sol";
-import "./mixins/MAssetProxyDispatcher.sol";
-import "../AssetProxy/interfaces/IAssetProxy.sol";
-
-contract MixinAssetProxyDispatcher is
-    Ownable,
-    LibExchangeErrors,
-    MAssetProxyDispatcher
-{
-    // Mapping from Asset Proxy Id's to their respective Asset Proxy
-    mapping (uint8 => IAssetProxy) public assetProxies;
-
-    /// @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
-        onlyOwner
-    {
-        // Ensure the existing asset proxy is not unintentionally overwritten
-        address currentAssetProxy = assetProxies[assetProxyId];
-        require(
-            oldAssetProxy == currentAssetProxy,
-            ASSET_PROXY_MISMATCH
-        );
-
-        IAssetProxy assetProxy = IAssetProxy(newAssetProxy);
-
-        // Ensure that the id of newAssetProxy matches the passed in assetProxyId, unless it is being reset to 0.
-        if (newAssetProxy != address(0)) {
-            uint8 newAssetProxyId = assetProxy.getProxyId();
-            require(
-                newAssetProxyId == assetProxyId,
-                ASSET_PROXY_ID_MISMATCH
-            );
-        }
-
-        // Add asset proxy and log registration.
-        assetProxies[assetProxyId] = assetProxy;
-        emit AssetProxySet(
-            assetProxyId,
-            newAssetProxy,
-            oldAssetProxy
-        );
-    }
-
-    /// @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)
-    {
-        return assetProxies[assetProxyId];
-    }
-
-    /// @dev Forwards arguments to assetProxy and calls `transferFrom`. Either succeeds or throws.
-    /// @param assetData Byte array encoded for the respective asset proxy.
-    /// @param assetProxyId Id of assetProxy to dispach to.
-    /// @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 assetData,
-        uint8 assetProxyId,
-        address from,
-        address to,
-        uint256 amount
-    )
-        internal
-    {
-        // Do nothing if no amount should be transferred.
-        if (amount > 0) {
-            // Lookup assetProxy
-            IAssetProxy assetProxy = assetProxies[assetProxyId];
-            // Ensure that assetProxy exists
-            require(
-                assetProxy != address(0),
-                ASSET_PROXY_DOES_NOT_EXIST
-            );
-            // transferFrom will either succeed or throw.
-            assetProxy.transferFrom(
-                assetData,
-                from,
-                to,
-                amount
-            );
-        }
-    }
-}
diff --git a/packages/contracts/src/contracts/current/test/TestAssetDataDecoders/TestAssetDataDecoders.sol b/packages/contracts/src/contracts/current/test/TestAssetDataDecoders/TestAssetDataDecoders.sol
deleted file mode 100644
index 5987291d2..000000000
--- a/packages/contracts/src/contracts/current/test/TestAssetDataDecoders/TestAssetDataDecoders.sol
+++ /dev/null
@@ -1,56 +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/AssetProxy/ERC20Proxy.sol";
-import "../../protocol/AssetProxy/ERC721Proxy.sol";
-
-contract TestAssetDataDecoders is
-    ERC721Proxy
-{
-    /// @dev Decodes ERC721 Asset data.
-    /// @param assetData Encoded byte array.
-    /// @return proxyId Intended ERC721 proxy id.
-    /// @return token ERC721 token address.
-    /// @return tokenId ERC721 token id.
-    /// @return receiverData Additional data with no specific format, which
-    ///                      is passed to the receiving contract's onERC721Received.
-    function publicDecodeERC721Data(bytes memory assetData)
-        public
-        pure
-        returns (
-            address token,
-            uint256 tokenId,
-            bytes memory receiverData
-        )
-    {
-        (
-            token,
-            tokenId,
-            receiverData
-        ) = decodeERC721AssetData(assetData);
-
-        return (
-            token,
-            tokenId,
-            receiverData
-        );
-    }
-}
diff --git a/packages/contracts/src/utils/address_utils.ts b/packages/contracts/src/utils/address_utils.ts
deleted file mode 100644
index a9fb6921a..000000000
--- a/packages/contracts/src/utils/address_utils.ts
+++ /dev/null
@@ -1,10 +0,0 @@
-import { crypto, generatePseudoRandomSalt } from '@0xproject/order-utils';
-
-export const addressUtils = {
-    generatePseudoRandomAddress(): string {
-        const randomBigNum = generatePseudoRandomSalt();
-        const randomBuff = crypto.solSHA3([randomBigNum]);
-        const randomAddress = `0x${randomBuff.slice(0, 20).toString('hex')}`;
-        return randomAddress;
-    },
-};
diff --git a/packages/contracts/src/utils/artifacts.ts b/packages/contracts/src/utils/artifacts.ts
deleted file mode 100644
index a46bab9ae..000000000
--- a/packages/contracts/src/utils/artifacts.ts
+++ /dev/null
@@ -1,51 +0,0 @@
-import { ContractArtifact } from '@0xproject/sol-compiler';
-
-import * as AssetProxyOwner from '../artifacts/AssetProxyOwner.json';
-import * as DummyERC20Token from '../artifacts/DummyERC20Token.json';
-import * as DummyERC721Receiver from '../artifacts/DummyERC721Receiver.json';
-import * as DummyERC721Token from '../artifacts/DummyERC721Token.json';
-import * as ERC20Proxy from '../artifacts/ERC20Proxy.json';
-import * as ERC721Proxy from '../artifacts/ERC721Proxy.json';
-import * as Exchange from '../artifacts/Exchange.json';
-import * as ExchangeWrapper from '../artifacts/ExchangeWrapper.json';
-import * as MixinAuthorizable from '../artifacts/MixinAuthorizable.json';
-import * as MultiSigWallet from '../artifacts/MultiSigWallet.json';
-import * as MultiSigWalletWithTimeLock from '../artifacts/MultiSigWalletWithTimeLock.json';
-import * as TestAssetDataDecoders from '../artifacts/TestAssetDataDecoders.json';
-import * as TestAssetProxyDispatcher from '../artifacts/TestAssetProxyDispatcher.json';
-import * as TestAssetProxyOwner from '../artifacts/TestAssetProxyOwner.json';
-import * as TestLibBytes from '../artifacts/TestLibBytes.json';
-import * as TestLibs from '../artifacts/TestLibs.json';
-import * as TestSignatureValidator from '../artifacts/TestSignatureValidator.json';
-import * as TestValidator from '../artifacts/TestValidator.json';
-import * as TestWallet from '../artifacts/TestWallet.json';
-import * as TokenRegistry from '../artifacts/TokenRegistry.json';
-import * as EtherToken from '../artifacts/WETH9.json';
-import * as Whitelist from '../artifacts/Whitelist.json';
-import * as ZRX from '../artifacts/ZRXToken.json';
-
-export const artifacts = {
-    AssetProxyOwner: (AssetProxyOwner as any) as ContractArtifact,
-    DummyERC20Token: (DummyERC20Token as any) as ContractArtifact,
-    DummyERC721Receiver: (DummyERC721Receiver as any) as ContractArtifact,
-    DummyERC721Token: (DummyERC721Token as any) as ContractArtifact,
-    ERC20Proxy: (ERC20Proxy as any) as ContractArtifact,
-    ERC721Proxy: (ERC721Proxy as any) as ContractArtifact,
-    Exchange: (Exchange as any) as ContractArtifact,
-    ExchangeWrapper: (ExchangeWrapper as any) as ContractArtifact,
-    EtherToken: (EtherToken as any) as ContractArtifact,
-    MixinAuthorizable: (MixinAuthorizable as any) as ContractArtifact,
-    MultiSigWallet: (MultiSigWallet as any) as ContractArtifact,
-    MultiSigWalletWithTimeLock: (MultiSigWalletWithTimeLock as any) as ContractArtifact,
-    TestAssetProxyOwner: (TestAssetProxyOwner as any) as ContractArtifact,
-    TestAssetProxyDispatcher: (TestAssetProxyDispatcher as any) as ContractArtifact,
-    TestAssetDataDecoders: (TestAssetDataDecoders as any) as ContractArtifact,
-    TestLibBytes: (TestLibBytes as any) as ContractArtifact,
-    TestLibs: (TestLibs as any) as ContractArtifact,
-    TestSignatureValidator: (TestSignatureValidator as any) as ContractArtifact,
-    TestValidator: (TestValidator as any) as ContractArtifact,
-    TestWallet: (TestWallet as any) as ContractArtifact,
-    TokenRegistry: (TokenRegistry as any) as ContractArtifact,
-    Whitelist: (Whitelist as any) as ContractArtifact,
-    ZRX: (ZRX as any) as ContractArtifact,
-};
diff --git a/packages/contracts/src/utils/assertions.ts b/packages/contracts/src/utils/assertions.ts
deleted file mode 100644
index 615e648f3..000000000
--- a/packages/contracts/src/utils/assertions.ts
+++ /dev/null
@@ -1,63 +0,0 @@
-import * as chai from 'chai';
-import * as _ from 'lodash';
-
-import { constants } from './constants';
-
-const expect = chai.expect;
-
-function _expectEitherErrorAsync<T>(p: Promise<T>, error1: string, error2: string): PromiseLike<void> {
-    return expect(p)
-        .to.be.rejected()
-        .then(e => {
-            expect(e).to.satisfy(
-                (err: Error) => _.includes(err.message, error1) || _.includes(err.message, error2),
-                `expected promise to reject with error message that includes "${error1}" or "${error2}", but got: ` +
-                    `"${e.message}"\n`,
-            );
-        });
-}
-
-/**
- * Rejects if the given Promise does not reject with an error indicating
- * insufficient funds.
- * @param p the Promise which is expected to reject
- * @returns a new Promise which will reject if the conditions are not met and
- * otherwise resolve with no value.
- */
-export function expectInsufficientFundsAsync<T>(p: Promise<T>): PromiseLike<void> {
-    return _expectEitherErrorAsync(p, 'insufficient funds', "sender doesn't have enough funds");
-}
-
-/**
- * Rejects if the given Promise does not reject with a "revert" error or the
- * given otherError.
- * @param p the Promise which is expected to reject
- * @param otherError the other error which is accepted as a valid reject error.
- * @returns a new Promise which will reject if the conditions are not met and
- * otherwise resolve with no value.
- */
-export function expectRevertOrOtherErrorAsync<T>(p: Promise<T>, otherError: string): PromiseLike<void> {
-    return _expectEitherErrorAsync(p, constants.REVERT, otherError);
-}
-
-/**
- * Rejects if the given Promise does not reject with a "revert" or "always
- * failing transaction" error.
- * @param p the Promise which is expected to reject
- * @returns a new Promise which will reject if the conditions are not met and
- * otherwise resolve with no value.
- */
-export function expectRevertOrAlwaysFailingTransactionAsync<T>(p: Promise<T>): PromiseLike<void> {
-    return expectRevertOrOtherErrorAsync(p, 'always failing transaction');
-}
-
-/**
- * Rejects if the given Promise does not reject with a "revert" or "Contract
- * call failed" error.
- * @param p the Promise which is expected to reject
- * @returns a new Promise which will reject if the conditions are not met and
- * otherwise resolve with no value.
- */
-export function expectRevertOrContractCallFailedAsync<T>(p: Promise<T>): PromiseLike<void> {
-    return expectRevertOrOtherErrorAsync<T>(p, 'Contract call failed');
-}
diff --git a/packages/contracts/src/utils/chai_setup.ts b/packages/contracts/src/utils/chai_setup.ts
deleted file mode 100644
index 1a8733093..000000000
--- a/packages/contracts/src/utils/chai_setup.ts
+++ /dev/null
@@ -1,13 +0,0 @@
-import * as chai from 'chai';
-import chaiAsPromised = require('chai-as-promised');
-import ChaiBigNumber = require('chai-bignumber');
-import * as dirtyChai from 'dirty-chai';
-
-export const chaiSetup = {
-    configure(): void {
-        chai.config.includeStack = true;
-        chai.use(ChaiBigNumber());
-        chai.use(dirtyChai);
-        chai.use(chaiAsPromised);
-    },
-};
diff --git a/packages/contracts/src/utils/constants.ts b/packages/contracts/src/utils/constants.ts
deleted file mode 100644
index f21b8c7a0..000000000
--- a/packages/contracts/src/utils/constants.ts
+++ /dev/null
@@ -1,62 +0,0 @@
-import { BigNumber } from '@0xproject/utils';
-import { Web3Wrapper } from '@0xproject/web3-wrapper';
-import * as ethUtil from 'ethereumjs-util';
-import * as _ from 'lodash';
-
-const TESTRPC_PRIVATE_KEYS_STRINGS = [
-    '0xf2f48ee19680706196e2e339e5da3491186e0c4c5030670656b0e0164837257d',
-    '0x5d862464fe9303452126c8bc94274b8c5f9874cbd219789b3eb2128075a76f72',
-    '0xdf02719c4df8b9b8ac7f551fcb5d9ef48fa27eef7a66453879f4d8fdc6e78fb1',
-    '0xff12e391b79415e941a94de3bf3a9aee577aed0731e297d5cfa0b8a1e02fa1d0',
-    '0x752dd9cf65e68cfaba7d60225cbdbc1f4729dd5e5507def72815ed0d8abc6249',
-    '0xefb595a0178eb79a8df953f87c5148402a224cdf725e88c0146727c6aceadccd',
-    '0x83c6d2cc5ddcf9711a6d59b417dc20eb48afd58d45290099e5987e3d768f328f',
-    '0xbb2d3f7c9583780a7d3904a2f55d792707c345f21de1bacb2d389934d82796b2',
-    '0xb2fd4d29c1390b71b8795ae81196bfd60293adf99f9d32a0aff06288fcdac55f',
-    '0x23cb7121166b9a2f93ae0b7c05bde02eae50d64449b2cbb42bc84e9d38d6cc89',
-];
-
-export const constants = {
-    INVALID_OPCODE: 'invalid opcode',
-    REVERT: 'revert',
-    LIB_BYTES_GREATER_THAN_ZERO_LENGTH_REQUIRED: 'GREATER_THAN_ZERO_LENGTH_REQUIRED',
-    LIB_BYTES_GREATER_OR_EQUAL_TO_4_LENGTH_REQUIRED: 'GREATER_OR_EQUAL_TO_4_LENGTH_REQUIRED',
-    LIB_BYTES_GREATER_OR_EQUAL_TO_20_LENGTH_REQUIRED: 'GREATER_OR_EQUAL_TO_20_LENGTH_REQUIRED',
-    LIB_BYTES_GREATER_OR_EQUAL_TO_32_LENGTH_REQUIRED: 'GREATER_OR_EQUAL_TO_32_LENGTH_REQUIRED',
-    LIB_BYTES_GREATER_OR_EQUAL_TO_NESTED_BYTES_LENGTH_REQUIRED: 'GREATER_OR_EQUAL_TO_NESTED_BYTES_LENGTH_REQUIRED',
-    LIB_BYTES_GREATER_OR_EQUAL_TO_SOURCE_BYTES_LENGTH_REQUIRED: 'GREATER_OR_EQUAL_TO_SOURCE_BYTES_LENGTH_REQUIRED',
-    ERC20_INSUFFICIENT_BALANCE: 'Insufficient balance to complete transfer.',
-    ERC20_INSUFFICIENT_ALLOWANCE: 'Insufficient allowance to complete transfer.',
-    EXCHANGE_LENGTH_GREATER_THAN_0_REQUIRED: 'LENGTH_GREATER_THAN_0_REQUIRED',
-    EXCHANGE_SIGNATURE_UNSUPPORTED: 'SIGNATURE_UNSUPPORTED',
-    EXCHANGE_SIGNATURE_ILLEGAL: 'SIGNATURE_ILLEGAL',
-    EXCHANGE_LENGTH_0_REQUIRED: 'LENGTH_0_REQUIRED',
-    EXCHANGE_LENGTH_65_REQUIRED: 'LENGTH_65_REQUIRED',
-    TESTRPC_NETWORK_ID: 50,
-    // Note(albrow): In practice V8 and most other engines limit the minimum
-    // interval for setInterval to 10ms. We still set it to 0 here in order to
-    // ensure we always use the minimum interval.
-    AWAIT_TRANSACTION_MINED_MS: 0,
-    MAX_ETHERTOKEN_WITHDRAW_GAS: 43000,
-    MAX_TOKEN_TRANSFERFROM_GAS: 80000,
-    MAX_TOKEN_APPROVE_GAS: 60000,
-    DUMMY_TOKEN_NAME: '',
-    DUMMY_TOKEN_SYMBOL: '',
-    DUMMY_TOKEN_DECIMALS: new BigNumber(18),
-    DUMMY_TOKEN_TOTAL_SUPPLY: new BigNumber(0),
-    NULL_BYTES: '0x',
-    NUM_DUMMY_ERC20_TO_DEPLOY: 3,
-    NUM_DUMMY_ERC721_TO_DEPLOY: 1,
-    NUM_ERC721_TOKENS_TO_MINT: 2,
-    NULL_ADDRESS: '0x0000000000000000000000000000000000000000',
-    UNLIMITED_ALLOWANCE_IN_BASE_UNITS: new BigNumber(2).pow(256).minus(1),
-    TESTRPC_PRIVATE_KEYS: _.map(TESTRPC_PRIVATE_KEYS_STRINGS, privateKeyString => ethUtil.toBuffer(privateKeyString)),
-    INITIAL_ERC20_BALANCE: Web3Wrapper.toBaseUnitAmount(new BigNumber(10000), 18),
-    INITIAL_ERC20_ALLOWANCE: Web3Wrapper.toBaseUnitAmount(new BigNumber(10000), 18),
-    STATIC_ORDER_PARAMS: {
-        makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(100), 18),
-        takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(200), 18),
-        makerFee: Web3Wrapper.toBaseUnitAmount(new BigNumber(1), 18),
-        takerFee: Web3Wrapper.toBaseUnitAmount(new BigNumber(1), 18),
-    },
-};
diff --git a/packages/contracts/src/utils/coverage.ts b/packages/contracts/src/utils/coverage.ts
deleted file mode 100644
index de29a3ecc..000000000
--- a/packages/contracts/src/utils/coverage.ts
+++ /dev/null
@@ -1,21 +0,0 @@
-import { devConstants } from '@0xproject/dev-utils';
-import { CoverageSubprovider, SolCompilerArtifactAdapter } from '@0xproject/sol-cov';
-import * as _ from 'lodash';
-
-let coverageSubprovider: CoverageSubprovider;
-
-export const coverage = {
-    getCoverageSubproviderSingleton(): CoverageSubprovider {
-        if (_.isUndefined(coverageSubprovider)) {
-            coverageSubprovider = coverage._getCoverageSubprovider();
-        }
-        return coverageSubprovider;
-    },
-    _getCoverageSubprovider(): CoverageSubprovider {
-        const defaultFromAddress = devConstants.TESTRPC_FIRST_ADDRESS;
-        const solCompilerArtifactAdapter = new SolCompilerArtifactAdapter();
-        const isVerbose = true;
-        const subprovider = new CoverageSubprovider(solCompilerArtifactAdapter, defaultFromAddress, isVerbose);
-        return subprovider;
-    },
-};
diff --git a/packages/contracts/src/utils/erc20_wrapper.ts b/packages/contracts/src/utils/erc20_wrapper.ts
deleted file mode 100644
index 91c9d50b7..000000000
--- a/packages/contracts/src/utils/erc20_wrapper.ts
+++ /dev/null
@@ -1,118 +0,0 @@
-import { BigNumber } from '@0xproject/utils';
-import { Web3Wrapper } from '@0xproject/web3-wrapper';
-import { Provider } from 'ethereum-types';
-import * as _ from 'lodash';
-
-import { DummyERC20TokenContract } from '../generated_contract_wrappers/dummy_e_r_c20_token';
-import { ERC20ProxyContract } from '../generated_contract_wrappers/e_r_c20_proxy';
-
-import { artifacts } from './artifacts';
-import { constants } from './constants';
-import { ERC20BalancesByOwner } from './types';
-import { txDefaults } from './web3_wrapper';
-
-export class ERC20Wrapper {
-    private _tokenOwnerAddresses: string[];
-    private _contractOwnerAddress: string;
-    private _web3Wrapper: Web3Wrapper;
-    private _provider: Provider;
-    private _dummyTokenContracts: DummyERC20TokenContract[];
-    private _proxyContract?: ERC20ProxyContract;
-    constructor(provider: Provider, tokenOwnerAddresses: string[], contractOwnerAddress: string) {
-        this._dummyTokenContracts = [];
-        this._web3Wrapper = new Web3Wrapper(provider);
-        this._provider = provider;
-        this._tokenOwnerAddresses = tokenOwnerAddresses;
-        this._contractOwnerAddress = contractOwnerAddress;
-    }
-    public async deployDummyTokensAsync(): Promise<DummyERC20TokenContract[]> {
-        for (let i = 0; i < constants.NUM_DUMMY_ERC20_TO_DEPLOY; i++) {
-            this._dummyTokenContracts.push(
-                await DummyERC20TokenContract.deployFrom0xArtifactAsync(
-                    artifacts.DummyERC20Token,
-                    this._provider,
-                    txDefaults,
-                    constants.DUMMY_TOKEN_NAME,
-                    constants.DUMMY_TOKEN_SYMBOL,
-                    constants.DUMMY_TOKEN_DECIMALS,
-                    constants.DUMMY_TOKEN_TOTAL_SUPPLY,
-                ),
-            );
-        }
-        return this._dummyTokenContracts;
-    }
-    public async deployProxyAsync(): Promise<ERC20ProxyContract> {
-        this._proxyContract = await ERC20ProxyContract.deployFrom0xArtifactAsync(
-            artifacts.ERC20Proxy,
-            this._provider,
-            txDefaults,
-        );
-        return this._proxyContract;
-    }
-    public async setBalancesAndAllowancesAsync(): Promise<void> {
-        this._validateDummyTokenContractsExistOrThrow();
-        this._validateProxyContractExistsOrThrow();
-        for (const dummyTokenContract of this._dummyTokenContracts) {
-            for (const tokenOwnerAddress of this._tokenOwnerAddresses) {
-                await this._web3Wrapper.awaitTransactionSuccessAsync(
-                    await dummyTokenContract.setBalance.sendTransactionAsync(
-                        tokenOwnerAddress,
-                        constants.INITIAL_ERC20_BALANCE,
-                        { from: this._contractOwnerAddress },
-                    ),
-                    constants.AWAIT_TRANSACTION_MINED_MS,
-                );
-                await this._web3Wrapper.awaitTransactionSuccessAsync(
-                    await dummyTokenContract.approve.sendTransactionAsync(
-                        (this._proxyContract as ERC20ProxyContract).address,
-                        constants.INITIAL_ERC20_ALLOWANCE,
-                        { from: tokenOwnerAddress },
-                    ),
-                    constants.AWAIT_TRANSACTION_MINED_MS,
-                );
-            }
-        }
-    }
-    public async getBalancesAsync(): Promise<ERC20BalancesByOwner> {
-        this._validateDummyTokenContractsExistOrThrow();
-        const balancesByOwner: ERC20BalancesByOwner = {};
-        const balances: BigNumber[] = [];
-        const balanceInfo: Array<{ tokenOwnerAddress: string; tokenAddress: string }> = [];
-        for (const dummyTokenContract of this._dummyTokenContracts) {
-            for (const tokenOwnerAddress of this._tokenOwnerAddresses) {
-                balances.push(await dummyTokenContract.balanceOf.callAsync(tokenOwnerAddress));
-                balanceInfo.push({
-                    tokenOwnerAddress,
-                    tokenAddress: dummyTokenContract.address,
-                });
-            }
-        }
-        _.forEach(balances, (balance, balanceIndex) => {
-            const tokenAddress = balanceInfo[balanceIndex].tokenAddress;
-            const tokenOwnerAddress = balanceInfo[balanceIndex].tokenOwnerAddress;
-            if (_.isUndefined(balancesByOwner[tokenOwnerAddress])) {
-                balancesByOwner[tokenOwnerAddress] = {};
-            }
-            const wrappedBalance = new BigNumber(balance);
-            balancesByOwner[tokenOwnerAddress][tokenAddress] = wrappedBalance;
-        });
-        return balancesByOwner;
-    }
-    public getTokenOwnerAddresses(): string[] {
-        return this._tokenOwnerAddresses;
-    }
-    public getTokenAddresses(): string[] {
-        const tokenAddresses = _.map(this._dummyTokenContracts, dummyTokenContract => dummyTokenContract.address);
-        return tokenAddresses;
-    }
-    private _validateDummyTokenContractsExistOrThrow(): void {
-        if (_.isUndefined(this._dummyTokenContracts)) {
-            throw new Error('Dummy ERC20 tokens not yet deployed, please call "deployDummyTokensAsync"');
-        }
-    }
-    private _validateProxyContractExistsOrThrow(): void {
-        if (_.isUndefined(this._proxyContract)) {
-            throw new Error('ERC20 proxy contract not yet deployed, please call "deployProxyAsync"');
-        }
-    }
-}
diff --git a/packages/contracts/src/utils/erc721_wrapper.ts b/packages/contracts/src/utils/erc721_wrapper.ts
deleted file mode 100644
index b20d9acd2..000000000
--- a/packages/contracts/src/utils/erc721_wrapper.ts
+++ /dev/null
@@ -1,147 +0,0 @@
-import { generatePseudoRandomSalt } from '@0xproject/order-utils';
-import { BigNumber } from '@0xproject/utils';
-import { Web3Wrapper } from '@0xproject/web3-wrapper';
-import { Provider } from 'ethereum-types';
-import * as _ from 'lodash';
-
-import { DummyERC721TokenContract } from '../generated_contract_wrappers/dummy_e_r_c721_token';
-import { ERC721ProxyContract } from '../generated_contract_wrappers/e_r_c721_proxy';
-
-import { artifacts } from './artifacts';
-import { constants } from './constants';
-import { ERC721TokenIdsByOwner } from './types';
-import { txDefaults } from './web3_wrapper';
-
-export class ERC721Wrapper {
-    private _tokenOwnerAddresses: string[];
-    private _contractOwnerAddress: string;
-    private _web3Wrapper: Web3Wrapper;
-    private _provider: Provider;
-    private _dummyTokenContracts: DummyERC721TokenContract[];
-    private _proxyContract?: ERC721ProxyContract;
-    private _initialTokenIdsByOwner: ERC721TokenIdsByOwner = {};
-    constructor(provider: Provider, tokenOwnerAddresses: string[], contractOwnerAddress: string) {
-        this._web3Wrapper = new Web3Wrapper(provider);
-        this._provider = provider;
-        this._dummyTokenContracts = [];
-        this._tokenOwnerAddresses = tokenOwnerAddresses;
-        this._contractOwnerAddress = contractOwnerAddress;
-    }
-    public async deployDummyTokensAsync(): Promise<DummyERC721TokenContract[]> {
-        for (let i = 0; i < constants.NUM_DUMMY_ERC721_TO_DEPLOY; i++) {
-            this._dummyTokenContracts.push(
-                await DummyERC721TokenContract.deployFrom0xArtifactAsync(
-                    artifacts.DummyERC721Token,
-                    this._provider,
-                    txDefaults,
-                    constants.DUMMY_TOKEN_NAME,
-                    constants.DUMMY_TOKEN_SYMBOL,
-                ),
-            );
-        }
-        return this._dummyTokenContracts;
-    }
-    public async deployProxyAsync(): Promise<ERC721ProxyContract> {
-        this._proxyContract = await ERC721ProxyContract.deployFrom0xArtifactAsync(
-            artifacts.ERC721Proxy,
-            this._provider,
-            txDefaults,
-        );
-        return this._proxyContract;
-    }
-    public async setBalancesAndAllowancesAsync(): Promise<void> {
-        this._validateDummyTokenContractsExistOrThrow();
-        this._validateProxyContractExistsOrThrow();
-        this._initialTokenIdsByOwner = {};
-        for (const dummyTokenContract of this._dummyTokenContracts) {
-            for (const tokenOwnerAddress of this._tokenOwnerAddresses) {
-                for (let i = 0; i < constants.NUM_ERC721_TOKENS_TO_MINT; i++) {
-                    const tokenId = generatePseudoRandomSalt();
-                    await this._web3Wrapper.awaitTransactionSuccessAsync(
-                        await dummyTokenContract.mint.sendTransactionAsync(tokenOwnerAddress, tokenId, {
-                            from: this._contractOwnerAddress,
-                        }),
-                        constants.AWAIT_TRANSACTION_MINED_MS,
-                    );
-                    if (_.isUndefined(this._initialTokenIdsByOwner[tokenOwnerAddress])) {
-                        this._initialTokenIdsByOwner[tokenOwnerAddress] = {
-                            [dummyTokenContract.address]: [],
-                        };
-                    }
-                    if (_.isUndefined(this._initialTokenIdsByOwner[tokenOwnerAddress][dummyTokenContract.address])) {
-                        this._initialTokenIdsByOwner[tokenOwnerAddress][dummyTokenContract.address] = [];
-                    }
-                    this._initialTokenIdsByOwner[tokenOwnerAddress][dummyTokenContract.address].push(tokenId);
-                }
-                const shouldApprove = true;
-                await this._web3Wrapper.awaitTransactionSuccessAsync(
-                    await dummyTokenContract.setApprovalForAll.sendTransactionAsync(
-                        (this._proxyContract as ERC721ProxyContract).address,
-                        shouldApprove,
-                        { from: tokenOwnerAddress },
-                    ),
-                    constants.AWAIT_TRANSACTION_MINED_MS,
-                );
-            }
-        }
-    }
-    public async getBalancesAsync(): Promise<ERC721TokenIdsByOwner> {
-        this._validateDummyTokenContractsExistOrThrow();
-        this._validateBalancesAndAllowancesSetOrThrow();
-        const tokenIdsByOwner: ERC721TokenIdsByOwner = {};
-        const tokenOwnerAddresses: string[] = [];
-        const tokenInfo: Array<{ tokenId: BigNumber; tokenAddress: string }> = [];
-        for (const dummyTokenContract of this._dummyTokenContracts) {
-            for (const tokenOwnerAddress of this._tokenOwnerAddresses) {
-                const initialTokenOwnerIds = this._initialTokenIdsByOwner[tokenOwnerAddress][
-                    dummyTokenContract.address
-                ];
-                for (const tokenId of initialTokenOwnerIds) {
-                    tokenOwnerAddresses.push(await dummyTokenContract.ownerOf.callAsync(tokenId));
-                    tokenInfo.push({
-                        tokenId,
-                        tokenAddress: dummyTokenContract.address,
-                    });
-                }
-            }
-        }
-        _.forEach(tokenOwnerAddresses, (tokenOwnerAddress, ownerIndex) => {
-            const tokenAddress = tokenInfo[ownerIndex].tokenAddress;
-            const tokenId = tokenInfo[ownerIndex].tokenId;
-            if (_.isUndefined(tokenIdsByOwner[tokenOwnerAddress])) {
-                tokenIdsByOwner[tokenOwnerAddress] = {
-                    [tokenAddress]: [],
-                };
-            }
-            if (_.isUndefined(tokenIdsByOwner[tokenOwnerAddress][tokenAddress])) {
-                tokenIdsByOwner[tokenOwnerAddress][tokenAddress] = [];
-            }
-            tokenIdsByOwner[tokenOwnerAddress][tokenAddress].push(tokenId);
-        });
-        return tokenIdsByOwner;
-    }
-    public getTokenOwnerAddresses(): string[] {
-        return this._tokenOwnerAddresses;
-    }
-    public getTokenAddresses(): string[] {
-        const tokenAddresses = _.map(this._dummyTokenContracts, dummyTokenContract => dummyTokenContract.address);
-        return tokenAddresses;
-    }
-    private _validateDummyTokenContractsExistOrThrow(): void {
-        if (_.isUndefined(this._dummyTokenContracts)) {
-            throw new Error('Dummy ERC721 tokens not yet deployed, please call "deployDummyTokensAsync"');
-        }
-    }
-    private _validateProxyContractExistsOrThrow(): void {
-        if (_.isUndefined(this._proxyContract)) {
-            throw new Error('ERC721 proxy contract not yet deployed, please call "deployProxyAsync"');
-        }
-    }
-    private _validateBalancesAndAllowancesSetOrThrow(): void {
-        if (_.keys(this._initialTokenIdsByOwner).length === 0) {
-            throw new Error(
-                'Dummy ERC721 balances and allowances not yet set, please call "setBalancesAndAllowancesAsync"',
-            );
-        }
-    }
-}
diff --git a/packages/contracts/src/utils/exchange_wrapper.ts b/packages/contracts/src/utils/exchange_wrapper.ts
deleted file mode 100644
index 06eb70644..000000000
--- a/packages/contracts/src/utils/exchange_wrapper.ts
+++ /dev/null
@@ -1,250 +0,0 @@
-import { AssetProxyId, SignedOrder } from '@0xproject/types';
-import { BigNumber } from '@0xproject/utils';
-import { Web3Wrapper } from '@0xproject/web3-wrapper';
-import { Provider, TransactionReceiptWithDecodedLogs } from 'ethereum-types';
-import * as _ from 'lodash';
-
-import { ExchangeContract } from '../generated_contract_wrappers/exchange';
-
-import { constants } from './constants';
-import { formatters } from './formatters';
-import { LogDecoder } from './log_decoder';
-import { orderUtils } from './order_utils';
-import { OrderInfo, SignedTransaction } from './types';
-
-export class ExchangeWrapper {
-    private _exchange: ExchangeContract;
-    private _web3Wrapper: Web3Wrapper;
-    private _logDecoder: LogDecoder;
-    constructor(exchangeContract: ExchangeContract, provider: Provider) {
-        this._exchange = exchangeContract;
-        this._web3Wrapper = new Web3Wrapper(provider);
-        this._logDecoder = new LogDecoder(this._web3Wrapper, this._exchange.address);
-    }
-    public async fillOrderAsync(
-        signedOrder: SignedOrder,
-        from: string,
-        opts: { takerAssetFillAmount?: BigNumber } = {},
-    ): Promise<TransactionReceiptWithDecodedLogs> {
-        const params = orderUtils.createFill(signedOrder, opts.takerAssetFillAmount);
-        const txHash = await this._exchange.fillOrder.sendTransactionAsync(
-            params.order,
-            params.takerAssetFillAmount,
-            params.signature,
-            { from },
-        );
-        const tx = await this._logDecoder.getTxWithDecodedLogsAsync(txHash);
-        return tx;
-    }
-    public async cancelOrderAsync(signedOrder: SignedOrder, from: string): Promise<TransactionReceiptWithDecodedLogs> {
-        const params = orderUtils.createCancel(signedOrder);
-        const txHash = await this._exchange.cancelOrder.sendTransactionAsync(params.order, { from });
-        const tx = await this._logDecoder.getTxWithDecodedLogsAsync(txHash);
-        return tx;
-    }
-    public async fillOrKillOrderAsync(
-        signedOrder: SignedOrder,
-        from: string,
-        opts: { takerAssetFillAmount?: BigNumber } = {},
-    ): Promise<TransactionReceiptWithDecodedLogs> {
-        const params = orderUtils.createFill(signedOrder, opts.takerAssetFillAmount);
-        const txHash = await this._exchange.fillOrKillOrder.sendTransactionAsync(
-            params.order,
-            params.takerAssetFillAmount,
-            params.signature,
-            { from },
-        );
-        const tx = await this._logDecoder.getTxWithDecodedLogsAsync(txHash);
-        return tx;
-    }
-    public async fillOrderNoThrowAsync(
-        signedOrder: SignedOrder,
-        from: string,
-        opts: { takerAssetFillAmount?: BigNumber; gas?: number } = {},
-    ): Promise<TransactionReceiptWithDecodedLogs> {
-        const params = orderUtils.createFill(signedOrder, opts.takerAssetFillAmount);
-        const txHash = await this._exchange.fillOrderNoThrow.sendTransactionAsync(
-            params.order,
-            params.takerAssetFillAmount,
-            params.signature,
-            { from, gas: opts.gas },
-        );
-        const tx = await this._logDecoder.getTxWithDecodedLogsAsync(txHash);
-        return tx;
-    }
-    public async batchFillOrdersAsync(
-        orders: SignedOrder[],
-        from: string,
-        opts: { takerAssetFillAmounts?: BigNumber[] } = {},
-    ): Promise<TransactionReceiptWithDecodedLogs> {
-        const params = formatters.createBatchFill(orders, opts.takerAssetFillAmounts);
-        const txHash = await this._exchange.batchFillOrders.sendTransactionAsync(
-            params.orders,
-            params.takerAssetFillAmounts,
-            params.signatures,
-            { from },
-        );
-        const tx = await this._logDecoder.getTxWithDecodedLogsAsync(txHash);
-        return tx;
-    }
-    public async batchFillOrKillOrdersAsync(
-        orders: SignedOrder[],
-        from: string,
-        opts: { takerAssetFillAmounts?: BigNumber[] } = {},
-    ): Promise<TransactionReceiptWithDecodedLogs> {
-        const params = formatters.createBatchFill(orders, opts.takerAssetFillAmounts);
-        const txHash = await this._exchange.batchFillOrKillOrders.sendTransactionAsync(
-            params.orders,
-            params.takerAssetFillAmounts,
-            params.signatures,
-            { from },
-        );
-        const tx = await this._logDecoder.getTxWithDecodedLogsAsync(txHash);
-        return tx;
-    }
-    public async batchFillOrdersNoThrowAsync(
-        orders: SignedOrder[],
-        from: string,
-        opts: { takerAssetFillAmounts?: BigNumber[]; gas?: number } = {},
-    ): Promise<TransactionReceiptWithDecodedLogs> {
-        const params = formatters.createBatchFill(orders, opts.takerAssetFillAmounts);
-        const txHash = await this._exchange.batchFillOrdersNoThrow.sendTransactionAsync(
-            params.orders,
-            params.takerAssetFillAmounts,
-            params.signatures,
-            { from, gas: opts.gas },
-        );
-        const tx = await this._logDecoder.getTxWithDecodedLogsAsync(txHash);
-        return tx;
-    }
-    public async marketSellOrdersAsync(
-        orders: SignedOrder[],
-        from: string,
-        opts: { takerAssetFillAmount: BigNumber },
-    ): Promise<TransactionReceiptWithDecodedLogs> {
-        const params = formatters.createMarketSellOrders(orders, opts.takerAssetFillAmount);
-        const txHash = await this._exchange.marketSellOrders.sendTransactionAsync(
-            params.orders,
-            params.takerAssetFillAmount,
-            params.signatures,
-            { from },
-        );
-        const tx = await this._logDecoder.getTxWithDecodedLogsAsync(txHash);
-        return tx;
-    }
-    public async marketSellOrdersNoThrowAsync(
-        orders: SignedOrder[],
-        from: string,
-        opts: { takerAssetFillAmount: BigNumber; gas?: number },
-    ): Promise<TransactionReceiptWithDecodedLogs> {
-        const params = formatters.createMarketSellOrders(orders, opts.takerAssetFillAmount);
-        const txHash = await this._exchange.marketSellOrdersNoThrow.sendTransactionAsync(
-            params.orders,
-            params.takerAssetFillAmount,
-            params.signatures,
-            { from, gas: opts.gas },
-        );
-        const tx = await this._logDecoder.getTxWithDecodedLogsAsync(txHash);
-        return tx;
-    }
-    public async marketBuyOrdersAsync(
-        orders: SignedOrder[],
-        from: string,
-        opts: { makerAssetFillAmount: BigNumber },
-    ): Promise<TransactionReceiptWithDecodedLogs> {
-        const params = formatters.createMarketBuyOrders(orders, opts.makerAssetFillAmount);
-        const txHash = await this._exchange.marketBuyOrders.sendTransactionAsync(
-            params.orders,
-            params.makerAssetFillAmount,
-            params.signatures,
-            { from },
-        );
-        const tx = await this._logDecoder.getTxWithDecodedLogsAsync(txHash);
-        return tx;
-    }
-    public async marketBuyOrdersNoThrowAsync(
-        orders: SignedOrder[],
-        from: string,
-        opts: { makerAssetFillAmount: BigNumber; gas?: number },
-    ): Promise<TransactionReceiptWithDecodedLogs> {
-        const params = formatters.createMarketBuyOrders(orders, opts.makerAssetFillAmount);
-        const txHash = await this._exchange.marketBuyOrdersNoThrow.sendTransactionAsync(
-            params.orders,
-            params.makerAssetFillAmount,
-            params.signatures,
-            { from, gas: opts.gas },
-        );
-        const tx = await this._logDecoder.getTxWithDecodedLogsAsync(txHash);
-        return tx;
-    }
-    public async batchCancelOrdersAsync(
-        orders: SignedOrder[],
-        from: string,
-    ): Promise<TransactionReceiptWithDecodedLogs> {
-        const params = formatters.createBatchCancel(orders);
-        const txHash = await this._exchange.batchCancelOrders.sendTransactionAsync(params.orders, { from });
-        const tx = await this._logDecoder.getTxWithDecodedLogsAsync(txHash);
-        return tx;
-    }
-    public async cancelOrdersUpToAsync(salt: BigNumber, from: string): Promise<TransactionReceiptWithDecodedLogs> {
-        const txHash = await this._exchange.cancelOrdersUpTo.sendTransactionAsync(salt, { from });
-        const tx = await this._logDecoder.getTxWithDecodedLogsAsync(txHash);
-        return tx;
-    }
-    public async registerAssetProxyAsync(
-        assetProxyId: AssetProxyId,
-        assetProxyAddress: string,
-        from: string,
-        opts: { oldAssetProxyAddressIfExists?: string } = {},
-    ): Promise<TransactionReceiptWithDecodedLogs> {
-        const oldAssetProxyAddress = _.isUndefined(opts.oldAssetProxyAddressIfExists)
-            ? constants.NULL_ADDRESS
-            : opts.oldAssetProxyAddressIfExists;
-        const txHash = await this._exchange.registerAssetProxy.sendTransactionAsync(
-            assetProxyId,
-            assetProxyAddress,
-            oldAssetProxyAddress,
-            { from },
-        );
-        const tx = await this._logDecoder.getTxWithDecodedLogsAsync(txHash);
-        return tx;
-    }
-    public async executeTransactionAsync(
-        signedTx: SignedTransaction,
-        from: string,
-    ): Promise<TransactionReceiptWithDecodedLogs> {
-        const txHash = await this._exchange.executeTransaction.sendTransactionAsync(
-            signedTx.salt,
-            signedTx.signerAddress,
-            signedTx.data,
-            signedTx.signature,
-            { from },
-        );
-        const tx = await this._logDecoder.getTxWithDecodedLogsAsync(txHash);
-        return tx;
-    }
-    public async getTakerAssetFilledAmountAsync(orderHashHex: string): Promise<BigNumber> {
-        const filledAmount = new BigNumber(await this._exchange.filled.callAsync(orderHashHex));
-        return filledAmount;
-    }
-    public async getOrderInfoAsync(signedOrder: SignedOrder): Promise<OrderInfo> {
-        const orderInfo = (await this._exchange.getOrderInfo.callAsync(signedOrder)) as OrderInfo;
-        return orderInfo;
-    }
-    public async matchOrdersAsync(
-        signedOrderLeft: SignedOrder,
-        signedOrderRight: SignedOrder,
-        from: string,
-    ): Promise<TransactionReceiptWithDecodedLogs> {
-        const params = orderUtils.createMatchOrders(signedOrderLeft, signedOrderRight);
-        const txHash = await this._exchange.matchOrders.sendTransactionAsync(
-            params.left,
-            params.right,
-            params.leftSignature,
-            params.rightSignature,
-            { from },
-        );
-        const tx = await this._logDecoder.getTxWithDecodedLogsAsync(txHash);
-        return tx;
-    }
-}
diff --git a/packages/contracts/src/utils/formatters.ts b/packages/contracts/src/utils/formatters.ts
deleted file mode 100644
index 32e4787d6..000000000
--- a/packages/contracts/src/utils/formatters.ts
+++ /dev/null
@@ -1,68 +0,0 @@
-import { SignedOrder } from '@0xproject/types';
-import { BigNumber } from '@0xproject/utils';
-import * as _ from 'lodash';
-
-import { constants } from './constants';
-import { orderUtils } from './order_utils';
-import { BatchCancelOrders, BatchFillOrders, MarketBuyOrders, MarketSellOrders } from './types';
-
-export const formatters = {
-    createBatchFill(signedOrders: SignedOrder[], takerAssetFillAmounts: BigNumber[] = []): BatchFillOrders {
-        const batchFill: BatchFillOrders = {
-            orders: [],
-            signatures: [],
-            takerAssetFillAmounts,
-        };
-        _.forEach(signedOrders, signedOrder => {
-            const orderWithoutExchangeAddress = orderUtils.getOrderWithoutExchangeAddress(signedOrder);
-            batchFill.orders.push(orderWithoutExchangeAddress);
-            batchFill.signatures.push(signedOrder.signature);
-            if (takerAssetFillAmounts.length < signedOrders.length) {
-                batchFill.takerAssetFillAmounts.push(signedOrder.takerAssetAmount);
-            }
-        });
-        return batchFill;
-    },
-    createMarketSellOrders(signedOrders: SignedOrder[], takerAssetFillAmount: BigNumber): MarketSellOrders {
-        const marketSellOrders: MarketSellOrders = {
-            orders: [],
-            signatures: [],
-            takerAssetFillAmount,
-        };
-        _.forEach(signedOrders, (signedOrder, i) => {
-            const orderWithoutExchangeAddress = orderUtils.getOrderWithoutExchangeAddress(signedOrder);
-            if (i !== 0) {
-                orderWithoutExchangeAddress.takerAssetData = constants.NULL_BYTES;
-            }
-            marketSellOrders.orders.push(orderWithoutExchangeAddress);
-            marketSellOrders.signatures.push(signedOrder.signature);
-        });
-        return marketSellOrders;
-    },
-    createMarketBuyOrders(signedOrders: SignedOrder[], makerAssetFillAmount: BigNumber): MarketBuyOrders {
-        const marketBuyOrders: MarketBuyOrders = {
-            orders: [],
-            signatures: [],
-            makerAssetFillAmount,
-        };
-        _.forEach(signedOrders, (signedOrder, i) => {
-            const orderWithoutExchangeAddress = orderUtils.getOrderWithoutExchangeAddress(signedOrder);
-            if (i !== 0) {
-                orderWithoutExchangeAddress.makerAssetData = constants.NULL_BYTES;
-            }
-            marketBuyOrders.orders.push(orderWithoutExchangeAddress);
-            marketBuyOrders.signatures.push(signedOrder.signature);
-        });
-        return marketBuyOrders;
-    },
-    createBatchCancel(signedOrders: SignedOrder[]): BatchCancelOrders {
-        const batchCancel: BatchCancelOrders = {
-            orders: [],
-        };
-        _.forEach(signedOrders, signedOrder => {
-            const orderWithoutExchangeAddress = orderUtils.getOrderWithoutExchangeAddress(signedOrder);
-            batchCancel.orders.push(orderWithoutExchangeAddress);
-        });
-        return batchCancel;
-    },
-};
diff --git a/packages/contracts/src/utils/increase_time.ts b/packages/contracts/src/utils/increase_time.ts
deleted file mode 100644
index 4565d8dbc..000000000
--- a/packages/contracts/src/utils/increase_time.ts
+++ /dev/null
@@ -1,31 +0,0 @@
-import * as _ from 'lodash';
-
-import { constants } from './constants';
-import { web3Wrapper } from './web3_wrapper';
-
-let firstAccount: string | undefined;
-
-/**
- * Increases time by the given number of seconds and then mines a block so that
- * the current block timestamp has the offset applied.
- * @param seconds the number of seconds by which to incrase the time offset.
- * @returns a new Promise which will resolve with the new total time offset or
- * reject if the time could not be increased.
- */
-export async function increaseTimeAndMineBlockAsync(seconds: number): Promise<number> {
-    if (_.isUndefined(firstAccount)) {
-        const accounts = await web3Wrapper.getAvailableAddressesAsync();
-        firstAccount = accounts[0];
-    }
-
-    const offset = await web3Wrapper.increaseTimeAsync(seconds);
-    // Note: we need to send a transaction after increasing time so
-    // that a block is actually mined. The contract looks at the
-    // last mined block for the timestamp.
-    await web3Wrapper.awaitTransactionSuccessAsync(
-        await web3Wrapper.sendTransactionAsync({ from: firstAccount, to: firstAccount, value: 0 }),
-        constants.AWAIT_TRANSACTION_MINED_MS,
-    );
-
-    return offset;
-}
diff --git a/packages/contracts/src/utils/log_decoder.ts b/packages/contracts/src/utils/log_decoder.ts
deleted file mode 100644
index 07127ba79..000000000
--- a/packages/contracts/src/utils/log_decoder.ts
+++ /dev/null
@@ -1,55 +0,0 @@
-import { ContractArtifact } from '@0xproject/sol-compiler';
-import { AbiDecoder, BigNumber } from '@0xproject/utils';
-import { Web3Wrapper } from '@0xproject/web3-wrapper';
-import {
-    AbiDefinition,
-    DecodedLogArgs,
-    LogEntry,
-    LogWithDecodedArgs,
-    RawLog,
-    TransactionReceiptWithDecodedLogs,
-} from 'ethereum-types';
-import * as _ from 'lodash';
-
-import { artifacts } from './artifacts';
-import { constants } from './constants';
-
-export class LogDecoder {
-    private _web3Wrapper: Web3Wrapper;
-    private _contractAddress: string;
-    private _abiDecoder: AbiDecoder;
-    public static wrapLogBigNumbers(log: any): any {
-        const argNames = _.keys(log.args);
-        for (const argName of argNames) {
-            const isWeb3BigNumber = _.startsWith(log.args[argName].constructor.toString(), 'function BigNumber(');
-            if (isWeb3BigNumber) {
-                log.args[argName] = new BigNumber(log.args[argName]);
-            }
-        }
-    }
-    constructor(web3Wrapper: Web3Wrapper, contractAddress: string) {
-        this._web3Wrapper = web3Wrapper;
-        this._contractAddress = contractAddress;
-        const abiArrays: AbiDefinition[][] = [];
-        _.forEach(artifacts, (artifact: ContractArtifact) => {
-            const compilerOutput = artifact.compilerOutput;
-            abiArrays.push(compilerOutput.abi);
-        });
-        this._abiDecoder = new AbiDecoder(abiArrays);
-    }
-    public decodeLogOrThrow<ArgsType extends DecodedLogArgs>(log: LogEntry): LogWithDecodedArgs<ArgsType> | RawLog {
-        const logWithDecodedArgsOrLog = this._abiDecoder.tryToDecodeLogOrNoop(log);
-        // tslint:disable-next-line:no-unnecessary-type-assertion
-        if (_.isUndefined((logWithDecodedArgsOrLog as LogWithDecodedArgs<ArgsType>).args)) {
-            throw new Error(`Unable to decode log: ${JSON.stringify(log)}`);
-        }
-        LogDecoder.wrapLogBigNumbers(logWithDecodedArgsOrLog);
-        return logWithDecodedArgsOrLog;
-    }
-    public async getTxWithDecodedLogsAsync(txHash: string): Promise<TransactionReceiptWithDecodedLogs> {
-        const tx = await this._web3Wrapper.awaitTransactionSuccessAsync(txHash, constants.AWAIT_TRANSACTION_MINED_MS);
-        tx.logs = _.filter(tx.logs, log => log.address === this._contractAddress);
-        tx.logs = _.map(tx.logs, log => this.decodeLogOrThrow(log));
-        return tx;
-    }
-}
diff --git a/packages/contracts/src/utils/match_order_tester.ts b/packages/contracts/src/utils/match_order_tester.ts
deleted file mode 100644
index fbb1b99db..000000000
--- a/packages/contracts/src/utils/match_order_tester.ts
+++ /dev/null
@@ -1,330 +0,0 @@
-import { assetProxyUtils, orderHashUtils } from '@0xproject/order-utils';
-import { AssetProxyId, SignedOrder } from '@0xproject/types';
-import { BigNumber } from '@0xproject/utils';
-import * as chai from 'chai';
-import * as _ from 'lodash';
-
-import { chaiSetup } from '../utils/chai_setup';
-import { ERC20Wrapper } from '../utils/erc20_wrapper';
-import { ERC721Wrapper } from '../utils/erc721_wrapper';
-import { ExchangeWrapper } from '../utils/exchange_wrapper';
-import {
-    ERC20BalancesByOwner,
-    ERC721TokenIdsByOwner,
-    TransferAmountsByMatchOrders as TransferAmounts,
-} from '../utils/types';
-
-chaiSetup.configure();
-const expect = chai.expect;
-
-export class MatchOrderTester {
-    private _exchangeWrapper: ExchangeWrapper;
-    private _erc20Wrapper: ERC20Wrapper;
-    private _erc721Wrapper: ERC721Wrapper;
-    private _feeTokenAddress: string;
-
-    /// @dev Compares a pair of ERC20 balances and a pair of ERC721 token owners.
-    /// @param expectedNewERC20BalancesByOwner Expected ERC20 balances.
-    /// @param realERC20BalancesByOwner Actual ERC20 balances.
-    /// @param expectedNewERC721TokenIdsByOwner Expected ERC721 token owners.
-    /// @param realERC721TokenIdsByOwner Actual ERC20 token owners.
-    /// @return True only if ERC20 balances match and ERC721 token owners match.
-    private static _compareExpectedAndRealBalances(
-        expectedNewERC20BalancesByOwner: ERC20BalancesByOwner,
-        realERC20BalancesByOwner: ERC20BalancesByOwner,
-        expectedNewERC721TokenIdsByOwner: ERC721TokenIdsByOwner,
-        realERC721TokenIdsByOwner: ERC721TokenIdsByOwner,
-    ): boolean {
-        // ERC20 Balances
-        const doesErc20BalancesMatch = _.isEqual(expectedNewERC20BalancesByOwner, realERC20BalancesByOwner);
-        if (!doesErc20BalancesMatch) {
-            return false;
-        }
-        // ERC721 Token Ids
-        const sortedExpectedNewERC721TokenIdsByOwner = _.mapValues(
-            expectedNewERC721TokenIdsByOwner,
-            tokenIdsByOwner => {
-                _.mapValues(tokenIdsByOwner, tokenIds => {
-                    _.sortBy(tokenIds);
-                });
-            },
-        );
-        const sortedNewERC721TokenIdsByOwner = _.mapValues(realERC721TokenIdsByOwner, tokenIdsByOwner => {
-            _.mapValues(tokenIdsByOwner, tokenIds => {
-                _.sortBy(tokenIds);
-            });
-        });
-        const doesErc721TokenIdsMatch = _.isEqual(
-            sortedExpectedNewERC721TokenIdsByOwner,
-            sortedNewERC721TokenIdsByOwner,
-        );
-        return doesErc721TokenIdsMatch;
-    }
-    /// @dev Constructs new MatchOrderTester.
-    /// @param exchangeWrapper Used to call to the Exchange.
-    /// @param erc20Wrapper Used to fetch ERC20 balances.
-    /// @param erc721Wrapper Used to fetch ERC721 token owners.
-    /// @param feeTokenAddress Address of ERC20 fee token.
-    constructor(
-        exchangeWrapper: ExchangeWrapper,
-        erc20Wrapper: ERC20Wrapper,
-        erc721Wrapper: ERC721Wrapper,
-        feeTokenAddress: string,
-    ) {
-        this._exchangeWrapper = exchangeWrapper;
-        this._erc20Wrapper = erc20Wrapper;
-        this._erc721Wrapper = erc721Wrapper;
-        this._feeTokenAddress = feeTokenAddress;
-    }
-    /// @dev Matches two complementary orders and validates results.
-    ///      Validation either succeeds or throws.
-    /// @param signedOrderLeft First matched order.
-    /// @param signedOrderRight Second matched order.
-    /// @param takerAddress Address of taker (the address who matched the two orders)
-    /// @param erc20BalancesByOwner Current ERC20 balances.
-    /// @param erc721TokenIdsByOwner Current ERC721 token owners.
-    /// @param initialTakerAssetFilledAmountLeft Current amount the left order has been filled.
-    /// @param initialTakerAssetFilledAmountRight Current amount the right order has been filled.
-    /// @return New ERC20 balances & ERC721 token owners.
-    public async matchOrdersAndVerifyBalancesAsync(
-        signedOrderLeft: SignedOrder,
-        signedOrderRight: SignedOrder,
-        takerAddress: string,
-        erc20BalancesByOwner: ERC20BalancesByOwner,
-        erc721TokenIdsByOwner: ERC721TokenIdsByOwner,
-        initialTakerAssetFilledAmountLeft?: BigNumber,
-        initialTakerAssetFilledAmountRight?: BigNumber,
-    ): Promise<[ERC20BalancesByOwner, ERC721TokenIdsByOwner]> {
-        // Verify Left order preconditions
-        const orderTakerAssetFilledAmountLeft = await this._exchangeWrapper.getTakerAssetFilledAmountAsync(
-            orderHashUtils.getOrderHashHex(signedOrderLeft),
-        );
-        const expectedOrderFilledAmountLeft = initialTakerAssetFilledAmountLeft
-            ? initialTakerAssetFilledAmountLeft
-            : new BigNumber(0);
-        expect(expectedOrderFilledAmountLeft).to.be.bignumber.equal(orderTakerAssetFilledAmountLeft);
-        // Verify Right order preconditions
-        const orderTakerAssetFilledAmountRight = await this._exchangeWrapper.getTakerAssetFilledAmountAsync(
-            orderHashUtils.getOrderHashHex(signedOrderRight),
-        );
-        const expectedOrderFilledAmountRight = initialTakerAssetFilledAmountRight
-            ? initialTakerAssetFilledAmountRight
-            : new BigNumber(0);
-        expect(expectedOrderFilledAmountRight).to.be.bignumber.equal(orderTakerAssetFilledAmountRight);
-        // Match left & right orders
-        await this._exchangeWrapper.matchOrdersAsync(signedOrderLeft, signedOrderRight, takerAddress);
-        const newERC20BalancesByOwner = await this._erc20Wrapper.getBalancesAsync();
-        const newERC721TokenIdsByOwner = await this._erc721Wrapper.getBalancesAsync();
-        // Calculate expected balance changes
-        const expectedTransferAmounts = await this._calculateExpectedTransferAmountsAsync(
-            signedOrderLeft,
-            signedOrderRight,
-            orderTakerAssetFilledAmountLeft,
-            orderTakerAssetFilledAmountRight,
-        );
-        let expectedERC20BalancesByOwner: ERC20BalancesByOwner;
-        let expectedERC721TokenIdsByOwner: ERC721TokenIdsByOwner;
-        [expectedERC20BalancesByOwner, expectedERC721TokenIdsByOwner] = this._calculateExpectedBalances(
-            signedOrderLeft,
-            signedOrderRight,
-            takerAddress,
-            erc20BalancesByOwner,
-            erc721TokenIdsByOwner,
-            expectedTransferAmounts,
-        );
-        // Assert our expected balances are equal to the actual balances
-        const didExpectedBalancesMatchRealBalances = MatchOrderTester._compareExpectedAndRealBalances(
-            expectedERC20BalancesByOwner,
-            newERC20BalancesByOwner,
-            expectedERC721TokenIdsByOwner,
-            newERC721TokenIdsByOwner,
-        );
-        expect(didExpectedBalancesMatchRealBalances).to.be.true();
-        return [newERC20BalancesByOwner, newERC721TokenIdsByOwner];
-    }
-    /// @dev Calculates expected transfer amounts between order makers, fee recipients, and
-    ///      the taker when two orders are matched.
-    /// @param signedOrderLeft First matched order.
-    /// @param signedOrderRight Second matched order.
-    /// @param orderTakerAssetFilledAmountLeft How much left order has been filled, prior to matching orders.
-    /// @param orderTakerAssetFilledAmountRight How much the right order has been filled, prior to matching orders.
-    /// @return TransferAmounts A struct containing the expected transfer amounts.
-    private async _calculateExpectedTransferAmountsAsync(
-        signedOrderLeft: SignedOrder,
-        signedOrderRight: SignedOrder,
-        orderTakerAssetFilledAmountLeft: BigNumber,
-        orderTakerAssetFilledAmountRight: BigNumber,
-    ): Promise<TransferAmounts> {
-        let amountBoughtByLeftMaker = await this._exchangeWrapper.getTakerAssetFilledAmountAsync(
-            orderHashUtils.getOrderHashHex(signedOrderLeft),
-        );
-        amountBoughtByLeftMaker = amountBoughtByLeftMaker.minus(orderTakerAssetFilledAmountLeft);
-        const amountSoldByLeftMaker = amountBoughtByLeftMaker
-            .times(signedOrderLeft.makerAssetAmount)
-            .dividedToIntegerBy(signedOrderLeft.takerAssetAmount);
-        const amountReceivedByRightMaker = amountBoughtByLeftMaker
-            .times(signedOrderRight.takerAssetAmount)
-            .dividedToIntegerBy(signedOrderRight.makerAssetAmount);
-        const amountReceivedByTaker = amountSoldByLeftMaker.minus(amountReceivedByRightMaker);
-        let amountBoughtByRightMaker = await this._exchangeWrapper.getTakerAssetFilledAmountAsync(
-            orderHashUtils.getOrderHashHex(signedOrderRight),
-        );
-        amountBoughtByRightMaker = amountBoughtByRightMaker.minus(orderTakerAssetFilledAmountRight);
-        const amountSoldByRightMaker = amountBoughtByRightMaker
-            .times(signedOrderRight.makerAssetAmount)
-            .dividedToIntegerBy(signedOrderRight.takerAssetAmount);
-        const amountReceivedByLeftMaker = amountSoldByRightMaker;
-        const feePaidByLeftMaker = signedOrderLeft.makerFee
-            .times(amountSoldByLeftMaker)
-            .dividedToIntegerBy(signedOrderLeft.makerAssetAmount);
-        const feePaidByRightMaker = signedOrderRight.makerFee
-            .times(amountSoldByRightMaker)
-            .dividedToIntegerBy(signedOrderRight.makerAssetAmount);
-        const feePaidByTakerLeft = signedOrderLeft.takerFee
-            .times(amountSoldByLeftMaker)
-            .dividedToIntegerBy(signedOrderLeft.makerAssetAmount);
-        const feePaidByTakerRight = signedOrderRight.takerFee
-            .times(amountSoldByRightMaker)
-            .dividedToIntegerBy(signedOrderRight.makerAssetAmount);
-        const totalFeePaidByTaker = feePaidByTakerLeft.add(feePaidByTakerRight);
-        const feeReceivedLeft = feePaidByLeftMaker.add(feePaidByTakerLeft);
-        const feeReceivedRight = feePaidByRightMaker.add(feePaidByTakerRight);
-        // Return values
-        const expectedTransferAmounts = {
-            // Left Maker
-            amountBoughtByLeftMaker,
-            amountSoldByLeftMaker,
-            amountReceivedByLeftMaker,
-            feePaidByLeftMaker,
-            // Right Maker
-            amountBoughtByRightMaker,
-            amountSoldByRightMaker,
-            amountReceivedByRightMaker,
-            feePaidByRightMaker,
-            // Taker
-            amountReceivedByTaker,
-            feePaidByTakerLeft,
-            feePaidByTakerRight,
-            totalFeePaidByTaker,
-            // Fee Recipients
-            feeReceivedLeft,
-            feeReceivedRight,
-        };
-        return expectedTransferAmounts;
-    }
-    /// @dev Calculates the expected balances of order makers, fee recipients, and the taker,
-    ///      as a result of matching two orders.
-    /// @param signedOrderLeft First matched order.
-    /// @param signedOrderRight Second matched order.
-    /// @param takerAddress Address of taker (the address who matched the two orders)
-    /// @param erc20BalancesByOwner Current ERC20 balances.
-    /// @param erc721TokenIdsByOwner Current ERC721 token owners.
-    /// @param expectedTransferAmounts A struct containing the expected transfer amounts.
-    /// @return Expected ERC20 balances & ERC721 token owners after orders have been matched.
-    private _calculateExpectedBalances(
-        signedOrderLeft: SignedOrder,
-        signedOrderRight: SignedOrder,
-        takerAddress: string,
-        erc20BalancesByOwner: ERC20BalancesByOwner,
-        erc721TokenIdsByOwner: ERC721TokenIdsByOwner,
-        expectedTransferAmounts: TransferAmounts,
-    ): [ERC20BalancesByOwner, ERC721TokenIdsByOwner] {
-        const makerAddressLeft = signedOrderLeft.makerAddress;
-        const makerAddressRight = signedOrderRight.makerAddress;
-        const feeRecipientAddressLeft = signedOrderLeft.feeRecipientAddress;
-        const feeRecipientAddressRight = signedOrderRight.feeRecipientAddress;
-        // Operations are performed on copies of the balances
-        const expectedNewERC20BalancesByOwner = _.cloneDeep(erc20BalancesByOwner);
-        const expectedNewERC721TokenIdsByOwner = _.cloneDeep(erc721TokenIdsByOwner);
-        // Left Maker Asset (Right Taker Asset)
-        const makerAssetProxyIdLeft = assetProxyUtils.decodeAssetDataId(signedOrderLeft.makerAssetData);
-        if (makerAssetProxyIdLeft === AssetProxyId.ERC20) {
-            // Decode asset data
-            const erc20AssetData = assetProxyUtils.decodeERC20AssetData(signedOrderLeft.makerAssetData);
-            const makerAssetAddressLeft = erc20AssetData.tokenAddress;
-            const takerAssetAddressRight = makerAssetAddressLeft;
-            // Left Maker
-            expectedNewERC20BalancesByOwner[makerAddressLeft][makerAssetAddressLeft] = expectedNewERC20BalancesByOwner[
-                makerAddressLeft
-            ][makerAssetAddressLeft].minus(expectedTransferAmounts.amountSoldByLeftMaker);
-            // Right Maker
-            expectedNewERC20BalancesByOwner[makerAddressRight][
-                takerAssetAddressRight
-            ] = expectedNewERC20BalancesByOwner[makerAddressRight][takerAssetAddressRight].add(
-                expectedTransferAmounts.amountReceivedByRightMaker,
-            );
-            // Taker
-            expectedNewERC20BalancesByOwner[takerAddress][makerAssetAddressLeft] = expectedNewERC20BalancesByOwner[
-                takerAddress
-            ][makerAssetAddressLeft].add(expectedTransferAmounts.amountReceivedByTaker);
-        } else if (makerAssetProxyIdLeft === AssetProxyId.ERC721) {
-            // Decode asset data
-            const erc721AssetData = assetProxyUtils.decodeERC721AssetData(signedOrderLeft.makerAssetData);
-            const makerAssetAddressLeft = erc721AssetData.tokenAddress;
-            const makerAssetIdLeft = erc721AssetData.tokenId;
-            const takerAssetAddressRight = makerAssetAddressLeft;
-            const takerAssetIdRight = makerAssetIdLeft;
-            // Left Maker
-            _.remove(expectedNewERC721TokenIdsByOwner[makerAddressLeft][makerAssetAddressLeft], makerAssetIdLeft);
-            // Right Maker
-            expectedNewERC721TokenIdsByOwner[makerAddressRight][takerAssetAddressRight].push(takerAssetIdRight);
-            // Taker: Since there is only 1 asset transferred, the taker does not receive any of the left maker asset.
-        }
-        // Left Taker Asset (Right Maker Asset)
-        // Note: This exchange is only between the order makers: the Taker does not receive any of the left taker asset.
-        const takerAssetProxyIdLeft = assetProxyUtils.decodeAssetDataId(signedOrderLeft.takerAssetData);
-        if (takerAssetProxyIdLeft === AssetProxyId.ERC20) {
-            // Decode asset data
-            const erc20AssetData = assetProxyUtils.decodeERC20AssetData(signedOrderLeft.takerAssetData);
-            const takerAssetAddressLeft = erc20AssetData.tokenAddress;
-            const makerAssetAddressRight = takerAssetAddressLeft;
-            // Left Maker
-            expectedNewERC20BalancesByOwner[makerAddressLeft][takerAssetAddressLeft] = expectedNewERC20BalancesByOwner[
-                makerAddressLeft
-            ][takerAssetAddressLeft].add(expectedTransferAmounts.amountReceivedByLeftMaker);
-            // Right Maker
-            expectedNewERC20BalancesByOwner[makerAddressRight][
-                makerAssetAddressRight
-            ] = expectedNewERC20BalancesByOwner[makerAddressRight][makerAssetAddressRight].minus(
-                expectedTransferAmounts.amountSoldByRightMaker,
-            );
-        } else if (takerAssetProxyIdLeft === AssetProxyId.ERC721) {
-            // Decode asset data
-            const erc721AssetData = assetProxyUtils.decodeERC721AssetData(signedOrderRight.makerAssetData);
-            const makerAssetAddressRight = erc721AssetData.tokenAddress;
-            const makerAssetIdRight = erc721AssetData.tokenId;
-            const takerAssetAddressLeft = makerAssetAddressRight;
-            const takerAssetIdLeft = makerAssetIdRight;
-            // Right Maker
-            _.remove(expectedNewERC721TokenIdsByOwner[makerAddressRight][makerAssetAddressRight], makerAssetIdRight);
-            // Left Maker
-            expectedNewERC721TokenIdsByOwner[makerAddressLeft][takerAssetAddressLeft].push(takerAssetIdLeft);
-        }
-        // Left Maker Fees
-        expectedNewERC20BalancesByOwner[makerAddressLeft][this._feeTokenAddress] = expectedNewERC20BalancesByOwner[
-            makerAddressLeft
-        ][this._feeTokenAddress].minus(expectedTransferAmounts.feePaidByLeftMaker);
-        // Right Maker Fees
-        expectedNewERC20BalancesByOwner[makerAddressRight][this._feeTokenAddress] = expectedNewERC20BalancesByOwner[
-            makerAddressRight
-        ][this._feeTokenAddress].minus(expectedTransferAmounts.feePaidByRightMaker);
-        // Taker Fees
-        expectedNewERC20BalancesByOwner[takerAddress][this._feeTokenAddress] = expectedNewERC20BalancesByOwner[
-            takerAddress
-        ][this._feeTokenAddress].minus(expectedTransferAmounts.totalFeePaidByTaker);
-        // Left Fee Recipient Fees
-        expectedNewERC20BalancesByOwner[feeRecipientAddressLeft][
-            this._feeTokenAddress
-        ] = expectedNewERC20BalancesByOwner[feeRecipientAddressLeft][this._feeTokenAddress].add(
-            expectedTransferAmounts.feeReceivedLeft,
-        );
-        // Right Fee Recipient Fees
-        expectedNewERC20BalancesByOwner[feeRecipientAddressRight][
-            this._feeTokenAddress
-        ] = expectedNewERC20BalancesByOwner[feeRecipientAddressRight][this._feeTokenAddress].add(
-            expectedTransferAmounts.feeReceivedRight,
-        );
-
-        return [expectedNewERC20BalancesByOwner, expectedNewERC721TokenIdsByOwner];
-    }
-}
diff --git a/packages/contracts/src/utils/multi_sig_wrapper.ts b/packages/contracts/src/utils/multi_sig_wrapper.ts
deleted file mode 100644
index b0d4fa8ab..000000000
--- a/packages/contracts/src/utils/multi_sig_wrapper.ts
+++ /dev/null
@@ -1,55 +0,0 @@
-import { BigNumber } from '@0xproject/utils';
-import { Web3Wrapper } from '@0xproject/web3-wrapper';
-import { Provider, TransactionReceiptWithDecodedLogs } from 'ethereum-types';
-import * as _ from 'lodash';
-
-import { AssetProxyOwnerContract } from '../generated_contract_wrappers/asset_proxy_owner';
-import { MultiSigWalletContract } from '../generated_contract_wrappers/multi_sig_wallet';
-
-import { LogDecoder } from './log_decoder';
-
-export class MultiSigWrapper {
-    private _multiSig: MultiSigWalletContract;
-    private _web3Wrapper: Web3Wrapper;
-    private _logDecoder: LogDecoder;
-    constructor(multiSigContract: MultiSigWalletContract, provider: Provider) {
-        this._multiSig = multiSigContract;
-        this._web3Wrapper = new Web3Wrapper(provider);
-        this._logDecoder = new LogDecoder(this._web3Wrapper, this._multiSig.address);
-    }
-    public async submitTransactionAsync(
-        destination: string,
-        data: string,
-        from: string,
-        opts: { value?: BigNumber } = {},
-    ): Promise<TransactionReceiptWithDecodedLogs> {
-        const value = _.isUndefined(opts.value) ? new BigNumber(0) : opts.value;
-        const txHash = await this._multiSig.submitTransaction.sendTransactionAsync(destination, value, data, {
-            from,
-        });
-        const tx = await this._logDecoder.getTxWithDecodedLogsAsync(txHash);
-        return tx;
-    }
-    public async confirmTransactionAsync(txId: BigNumber, from: string): Promise<TransactionReceiptWithDecodedLogs> {
-        const txHash = await this._multiSig.confirmTransaction.sendTransactionAsync(txId, { from });
-        const tx = await this._logDecoder.getTxWithDecodedLogsAsync(txHash);
-        return tx;
-    }
-    public async executeTransactionAsync(txId: BigNumber, from: string): Promise<TransactionReceiptWithDecodedLogs> {
-        const txHash = await this._multiSig.executeTransaction.sendTransactionAsync(txId, { from });
-        const tx = await this._logDecoder.getTxWithDecodedLogsAsync(txHash);
-        return tx;
-    }
-    public async executeRemoveAuthorizedAddressAtIndexAsync(
-        txId: BigNumber,
-        from: string,
-    ): Promise<TransactionReceiptWithDecodedLogs> {
-        // tslint:disable-next-line:no-unnecessary-type-assertion
-        const txHash = await (this
-            ._multiSig as AssetProxyOwnerContract).executeRemoveAuthorizedAddressAtIndex.sendTransactionAsync(txId, {
-            from,
-        });
-        const tx = await this._logDecoder.getTxWithDecodedLogsAsync(txHash);
-        return tx;
-    }
-}
diff --git a/packages/contracts/src/utils/order_factory.ts b/packages/contracts/src/utils/order_factory.ts
deleted file mode 100644
index 009dbc396..000000000
--- a/packages/contracts/src/utils/order_factory.ts
+++ /dev/null
@@ -1,37 +0,0 @@
-import { generatePseudoRandomSalt, orderHashUtils } from '@0xproject/order-utils';
-import { Order, SignatureType, SignedOrder } from '@0xproject/types';
-import { BigNumber } from '@0xproject/utils';
-
-import { constants } from './constants';
-import { signingUtils } from './signing_utils';
-
-export class OrderFactory {
-    private _defaultOrderParams: Partial<Order>;
-    private _privateKey: Buffer;
-    constructor(privateKey: Buffer, defaultOrderParams: Partial<Order>) {
-        this._defaultOrderParams = defaultOrderParams;
-        this._privateKey = privateKey;
-    }
-    public newSignedOrder(
-        customOrderParams: Partial<Order> = {},
-        signatureType: SignatureType = SignatureType.EthSign,
-    ): SignedOrder {
-        const tenMinutes = 10 * 60 * 1000;
-        const randomExpiration = new BigNumber(Date.now() + tenMinutes);
-        const order = ({
-            senderAddress: constants.NULL_ADDRESS,
-            expirationTimeSeconds: randomExpiration,
-            salt: generatePseudoRandomSalt(),
-            takerAddress: constants.NULL_ADDRESS,
-            ...this._defaultOrderParams,
-            ...customOrderParams,
-        } as any) as Order;
-        const orderHashBuff = orderHashUtils.getOrderHashBuffer(order);
-        const signature = signingUtils.signMessage(orderHashBuff, this._privateKey, signatureType);
-        const signedOrder = {
-            ...order,
-            signature: `0x${signature.toString('hex')}`,
-        };
-        return signedOrder;
-    }
-}
diff --git a/packages/contracts/src/utils/order_utils.ts b/packages/contracts/src/utils/order_utils.ts
deleted file mode 100644
index a9f994d80..000000000
--- a/packages/contracts/src/utils/order_utils.ts
+++ /dev/null
@@ -1,51 +0,0 @@
-import { OrderWithoutExchangeAddress, SignedOrder } from '@0xproject/types';
-import { BigNumber } from '@0xproject/utils';
-
-import { constants } from './constants';
-import { CancelOrder, MatchOrder } from './types';
-
-export const orderUtils = {
-    createFill: (signedOrder: SignedOrder, takerAssetFillAmount?: BigNumber) => {
-        const fill = {
-            order: orderUtils.getOrderWithoutExchangeAddress(signedOrder),
-            takerAssetFillAmount: takerAssetFillAmount || signedOrder.takerAssetAmount,
-            signature: signedOrder.signature,
-        };
-        return fill;
-    },
-    createCancel(signedOrder: SignedOrder, takerAssetCancelAmount?: BigNumber): CancelOrder {
-        const cancel = {
-            order: orderUtils.getOrderWithoutExchangeAddress(signedOrder),
-            takerAssetCancelAmount: takerAssetCancelAmount || signedOrder.takerAssetAmount,
-        };
-        return cancel;
-    },
-    getOrderWithoutExchangeAddress(signedOrder: SignedOrder): OrderWithoutExchangeAddress {
-        const orderStruct = {
-            senderAddress: signedOrder.senderAddress,
-            makerAddress: signedOrder.makerAddress,
-            takerAddress: signedOrder.takerAddress,
-            feeRecipientAddress: signedOrder.feeRecipientAddress,
-            makerAssetAmount: signedOrder.makerAssetAmount,
-            takerAssetAmount: signedOrder.takerAssetAmount,
-            makerFee: signedOrder.makerFee,
-            takerFee: signedOrder.takerFee,
-            expirationTimeSeconds: signedOrder.expirationTimeSeconds,
-            salt: signedOrder.salt,
-            makerAssetData: signedOrder.makerAssetData,
-            takerAssetData: signedOrder.takerAssetData,
-        };
-        return orderStruct;
-    },
-    createMatchOrders(signedOrderLeft: SignedOrder, signedOrderRight: SignedOrder): MatchOrder {
-        const fill = {
-            left: orderUtils.getOrderWithoutExchangeAddress(signedOrderLeft),
-            right: orderUtils.getOrderWithoutExchangeAddress(signedOrderRight),
-            leftSignature: signedOrderLeft.signature,
-            rightSignature: signedOrderRight.signature,
-        };
-        fill.right.makerAssetData = constants.NULL_BYTES;
-        fill.right.takerAssetData = constants.NULL_BYTES;
-        return fill;
-    },
-};
diff --git a/packages/contracts/src/utils/profiler.ts b/packages/contracts/src/utils/profiler.ts
deleted file mode 100644
index 85ee24f22..000000000
--- a/packages/contracts/src/utils/profiler.ts
+++ /dev/null
@@ -1,27 +0,0 @@
-import { devConstants } from '@0xproject/dev-utils';
-import { ProfilerSubprovider, SolCompilerArtifactAdapter } from '@0xproject/sol-cov';
-import * as _ from 'lodash';
-
-let profilerSubprovider: ProfilerSubprovider;
-
-export const profiler = {
-    start(): void {
-        profiler.getProfilerSubproviderSingleton().start();
-    },
-    stop(): void {
-        profiler.getProfilerSubproviderSingleton().stop();
-    },
-    getProfilerSubproviderSingleton(): ProfilerSubprovider {
-        if (_.isUndefined(profilerSubprovider)) {
-            profilerSubprovider = profiler._getProfilerSubprovider();
-        }
-        return profilerSubprovider;
-    },
-    _getProfilerSubprovider(): ProfilerSubprovider {
-        const defaultFromAddress = devConstants.TESTRPC_FIRST_ADDRESS;
-        const solCompilerArtifactAdapter = new SolCompilerArtifactAdapter();
-        const isVerbose = true;
-        const subprovider = new ProfilerSubprovider(solCompilerArtifactAdapter, defaultFromAddress, isVerbose);
-        return subprovider;
-    },
-};
diff --git a/packages/contracts/src/utils/revert_trace.ts b/packages/contracts/src/utils/revert_trace.ts
deleted file mode 100644
index 0bf8384bc..000000000
--- a/packages/contracts/src/utils/revert_trace.ts
+++ /dev/null
@@ -1,21 +0,0 @@
-import { devConstants } from '@0xproject/dev-utils';
-import { RevertTraceSubprovider, SolCompilerArtifactAdapter } from '@0xproject/sol-cov';
-import * as _ from 'lodash';
-
-let revertTraceSubprovider: RevertTraceSubprovider;
-
-export const revertTrace = {
-    getRevertTraceSubproviderSingleton(): RevertTraceSubprovider {
-        if (_.isUndefined(revertTraceSubprovider)) {
-            revertTraceSubprovider = revertTrace._getRevertTraceSubprovider();
-        }
-        return revertTraceSubprovider;
-    },
-    _getRevertTraceSubprovider(): RevertTraceSubprovider {
-        const defaultFromAddress = devConstants.TESTRPC_FIRST_ADDRESS;
-        const solCompilerArtifactAdapter = new SolCompilerArtifactAdapter();
-        const isVerbose = true;
-        const subprovider = new RevertTraceSubprovider(solCompilerArtifactAdapter, defaultFromAddress, isVerbose);
-        return subprovider;
-    },
-};
diff --git a/packages/contracts/src/utils/signing_utils.ts b/packages/contracts/src/utils/signing_utils.ts
deleted file mode 100644
index 9c711c72c..000000000
--- a/packages/contracts/src/utils/signing_utils.ts
+++ /dev/null
@@ -1,29 +0,0 @@
-import { SignatureType } from '@0xproject/types';
-import * as ethUtil from 'ethereumjs-util';
-
-export const signingUtils = {
-    signMessage(message: Buffer, privateKey: Buffer, signatureType: SignatureType): Buffer {
-        if (signatureType === SignatureType.EthSign) {
-            const prefixedMessage = ethUtil.hashPersonalMessage(message);
-            const ecSignature = ethUtil.ecsign(prefixedMessage, privateKey);
-            const signature = Buffer.concat([
-                ethUtil.toBuffer(ecSignature.v),
-                ecSignature.r,
-                ecSignature.s,
-                ethUtil.toBuffer(signatureType),
-            ]);
-            return signature;
-        } else if (signatureType === SignatureType.EIP712) {
-            const ecSignature = ethUtil.ecsign(message, privateKey);
-            const signature = Buffer.concat([
-                ethUtil.toBuffer(ecSignature.v),
-                ecSignature.r,
-                ecSignature.s,
-                ethUtil.toBuffer(signatureType),
-            ]);
-            return signature;
-        } else {
-            throw new Error(`${signatureType} is not a valid signature type`);
-        }
-    },
-};
diff --git a/packages/contracts/src/utils/token_registry_wrapper.ts b/packages/contracts/src/utils/token_registry_wrapper.ts
deleted file mode 100644
index 91895aa59..000000000
--- a/packages/contracts/src/utils/token_registry_wrapper.ts
+++ /dev/null
@@ -1,66 +0,0 @@
-import { Web3Wrapper } from '@0xproject/web3-wrapper';
-import { Provider } from 'ethereum-types';
-
-import { TokenRegistryContract } from '../generated_contract_wrappers/token_registry';
-
-import { Token } from './types';
-
-import { constants } from './constants';
-
-export class TokenRegWrapper {
-    private _tokenReg: TokenRegistryContract;
-    private _web3Wrapper: Web3Wrapper;
-    constructor(tokenRegContract: TokenRegistryContract, provider: Provider) {
-        this._tokenReg = tokenRegContract;
-        this._web3Wrapper = new Web3Wrapper(provider);
-    }
-    public async addTokenAsync(token: Token, from: string): Promise<string> {
-        const txHash = await this._tokenReg.addToken.sendTransactionAsync(
-            token.address as string,
-            token.name,
-            token.symbol,
-            token.decimals,
-            token.ipfsHash,
-            token.swarmHash,
-            { from },
-        );
-        await this._web3Wrapper.awaitTransactionSuccessAsync(txHash, constants.AWAIT_TRANSACTION_MINED_MS);
-        return txHash;
-    }
-    public async getTokenMetaDataAsync(tokenAddress: string): Promise<Token> {
-        const data = await this._tokenReg.getTokenMetaData.callAsync(tokenAddress);
-        const token: Token = {
-            address: data[0],
-            name: data[1],
-            symbol: data[2],
-            decimals: data[3],
-            ipfsHash: data[4],
-            swarmHash: data[5],
-        };
-        return token;
-    }
-    public async getTokenByNameAsync(tokenName: string): Promise<Token> {
-        const data = await this._tokenReg.getTokenByName.callAsync(tokenName);
-        const token: Token = {
-            address: data[0],
-            name: data[1],
-            symbol: data[2],
-            decimals: data[3],
-            ipfsHash: data[4],
-            swarmHash: data[5],
-        };
-        return token;
-    }
-    public async getTokenBySymbolAsync(tokenSymbol: string): Promise<Token> {
-        const data = await this._tokenReg.getTokenBySymbol.callAsync(tokenSymbol);
-        const token: Token = {
-            address: data[0],
-            name: data[1],
-            symbol: data[2],
-            decimals: data[3],
-            ipfsHash: data[4],
-            swarmHash: data[5],
-        };
-        return token;
-    }
-}
diff --git a/packages/contracts/src/utils/transaction_factory.ts b/packages/contracts/src/utils/transaction_factory.ts
deleted file mode 100644
index 348c0715d..000000000
--- a/packages/contracts/src/utils/transaction_factory.ts
+++ /dev/null
@@ -1,47 +0,0 @@
-import { EIP712Schema, EIP712Types, EIP712Utils, generatePseudoRandomSalt } from '@0xproject/order-utils';
-import { SignatureType } from '@0xproject/types';
-import * as ethUtil from 'ethereumjs-util';
-
-import { signingUtils } from './signing_utils';
-import { SignedTransaction } from './types';
-
-const EIP712_ZEROEX_TRANSACTION_SCHEMA: EIP712Schema = {
-    name: 'ZeroExTransaction',
-    parameters: [
-        { name: 'salt', type: EIP712Types.Uint256 },
-        { name: 'signerAddress', type: EIP712Types.Address },
-        { name: 'data', type: EIP712Types.Bytes },
-    ],
-};
-
-export class TransactionFactory {
-    private _signerBuff: Buffer;
-    private _exchangeAddress: string;
-    private _privateKey: Buffer;
-    constructor(privateKey: Buffer, exchangeAddress: string) {
-        this._privateKey = privateKey;
-        this._exchangeAddress = exchangeAddress;
-        this._signerBuff = ethUtil.privateToAddress(this._privateKey);
-    }
-    public newSignedTransaction(data: string, signatureType: SignatureType = SignatureType.EthSign): SignedTransaction {
-        const salt = generatePseudoRandomSalt();
-        const signerAddress = `0x${this._signerBuff.toString('hex')}`;
-        const executeTransactionData = {
-            salt,
-            signerAddress,
-            data,
-        };
-        const executeTransactionHashBuff = EIP712Utils.structHash(
-            EIP712_ZEROEX_TRANSACTION_SCHEMA,
-            executeTransactionData,
-        );
-        const txHash = EIP712Utils.createEIP712Message(executeTransactionHashBuff, this._exchangeAddress);
-        const signature = signingUtils.signMessage(txHash, this._privateKey, signatureType);
-        const signedTx = {
-            exchangeAddress: this._exchangeAddress,
-            signature: `0x${signature.toString('hex')}`,
-            ...executeTransactionData,
-        };
-        return signedTx;
-    }
-}
diff --git a/packages/contracts/src/utils/types.ts b/packages/contracts/src/utils/types.ts
deleted file mode 100644
index 5dfac64fc..000000000
--- a/packages/contracts/src/utils/types.ts
+++ /dev/null
@@ -1,152 +0,0 @@
-import { OrderWithoutExchangeAddress } from '@0xproject/types';
-import { BigNumber } from '@0xproject/utils';
-import { AbiDefinition } from 'ethereum-types';
-
-export interface ERC20BalancesByOwner {
-    [ownerAddress: string]: {
-        [tokenAddress: string]: BigNumber;
-    };
-}
-
-export interface ERC721TokenIdsByOwner {
-    [ownerAddress: string]: {
-        [tokenAddress: string]: BigNumber[];
-    };
-}
-
-export interface SubmissionContractEventArgs {
-    transactionId: BigNumber;
-}
-
-export interface BatchFillOrders {
-    orders: OrderWithoutExchangeAddress[];
-    signatures: string[];
-    takerAssetFillAmounts: BigNumber[];
-}
-
-export interface MarketSellOrders {
-    orders: OrderWithoutExchangeAddress[];
-    signatures: string[];
-    takerAssetFillAmount: BigNumber;
-}
-
-export interface MarketBuyOrders {
-    orders: OrderWithoutExchangeAddress[];
-    signatures: string[];
-    makerAssetFillAmount: BigNumber;
-}
-
-export interface BatchCancelOrders {
-    orders: OrderWithoutExchangeAddress[];
-}
-
-export interface CancelOrdersBefore {
-    salt: BigNumber;
-}
-
-export interface TransactionDataParams {
-    name: string;
-    abi: AbiDefinition[];
-    args: any[];
-}
-
-export interface MultiSigConfig {
-    owners: string[];
-    confirmationsRequired: number;
-    secondsRequired: number;
-}
-
-export interface MultiSigConfigByNetwork {
-    [networkName: string]: MultiSigConfig;
-}
-
-export interface Token {
-    address?: string;
-    name: string;
-    symbol: string;
-    decimals: number;
-    ipfsHash: string;
-    swarmHash: string;
-}
-
-export enum OrderStatus {
-    INVALID,
-    INVALID_MAKER_ASSET_AMOUNT,
-    INVALID_TAKER_ASSET_AMOUNT,
-    FILLABLE,
-    EXPIRED,
-    FULLY_FILLED,
-    CANCELLED,
-}
-
-export enum ContractName {
-    TokenRegistry = 'TokenRegistry',
-    MultiSigWalletWithTimeLock = 'MultiSigWalletWithTimeLock',
-    Exchange = 'Exchange',
-    ZRXToken = 'ZRXToken',
-    DummyERC20Token = 'DummyERC20Token',
-    EtherToken = 'WETH9',
-    AssetProxyOwner = 'AssetProxyOwner',
-    AccountLevels = 'AccountLevels',
-    EtherDelta = 'EtherDelta',
-    Arbitrage = 'Arbitrage',
-    TestAssetDataDecoders = 'TestAssetDataDecoders',
-    TestAssetProxyDispatcher = 'TestAssetProxyDispatcher',
-    TestLibs = 'TestLibs',
-    TestSignatureValidator = 'TestSignatureValidator',
-    ERC20Proxy = 'ERC20Proxy',
-    ERC721Proxy = 'ERC721Proxy',
-    DummyERC721Receiver = 'DummyERC721Receiver',
-    DummyERC721Token = 'DummyERC721Token',
-    TestLibBytes = 'TestLibBytes',
-    TestWallet = 'TestWallet',
-    Authorizable = 'Authorizable',
-    Whitelist = 'Whitelist',
-}
-
-export interface SignedTransaction {
-    exchangeAddress: string;
-    salt: BigNumber;
-    signerAddress: string;
-    data: string;
-    signature: string;
-}
-
-export interface TransferAmountsByMatchOrders {
-    // Left Maker
-    amountBoughtByLeftMaker: BigNumber;
-    amountSoldByLeftMaker: BigNumber;
-    amountReceivedByLeftMaker: BigNumber;
-    feePaidByLeftMaker: BigNumber;
-    // Right Maker
-    amountBoughtByRightMaker: BigNumber;
-    amountSoldByRightMaker: BigNumber;
-    amountReceivedByRightMaker: BigNumber;
-    feePaidByRightMaker: BigNumber;
-    // Taker
-    amountReceivedByTaker: BigNumber;
-    feePaidByTakerLeft: BigNumber;
-    feePaidByTakerRight: BigNumber;
-    totalFeePaidByTaker: BigNumber;
-    // Fee Recipients
-    feeReceivedLeft: BigNumber;
-    feeReceivedRight: BigNumber;
-}
-
-export interface OrderInfo {
-    orderStatus: number;
-    orderHash: string;
-    orderTakerAssetFilledAmount: BigNumber;
-}
-
-export interface CancelOrder {
-    order: OrderWithoutExchangeAddress;
-    takerAssetCancelAmount: BigNumber;
-}
-
-export interface MatchOrder {
-    left: OrderWithoutExchangeAddress;
-    right: OrderWithoutExchangeAddress;
-    leftSignature: string;
-    rightSignature: string;
-}
diff --git a/packages/contracts/src/utils/web3_wrapper.ts b/packages/contracts/src/utils/web3_wrapper.ts
deleted file mode 100644
index c9d83a02d..000000000
--- a/packages/contracts/src/utils/web3_wrapper.ts
+++ /dev/null
@@ -1,82 +0,0 @@
-import { devConstants, env, EnvVars, web3Factory } from '@0xproject/dev-utils';
-import { prependSubprovider } from '@0xproject/subproviders';
-import { logUtils } from '@0xproject/utils';
-import { Web3Wrapper } from '@0xproject/web3-wrapper';
-import * as _ from 'lodash';
-
-import { coverage } from './coverage';
-import { profiler } from './profiler';
-import { revertTrace } from './revert_trace';
-
-enum ProviderType {
-    Ganache = 'ganache',
-    Geth = 'geth',
-}
-
-let testProvider: ProviderType;
-switch (process.env.TEST_PROVIDER) {
-    case undefined:
-        testProvider = ProviderType.Ganache;
-        break;
-    case 'ganache':
-        testProvider = ProviderType.Ganache;
-        break;
-    case 'geth':
-        testProvider = ProviderType.Geth;
-        break;
-    default:
-        throw new Error(`Unknown TEST_PROVIDER: ${process.env.TEST_PROVIDER}`);
-}
-
-const ganacheTxDefaults = {
-    from: devConstants.TESTRPC_FIRST_ADDRESS,
-    gas: devConstants.GAS_LIMIT,
-};
-const gethTxDefaults = {
-    from: devConstants.TESTRPC_FIRST_ADDRESS,
-};
-export const txDefaults = testProvider === ProviderType.Ganache ? ganacheTxDefaults : gethTxDefaults;
-
-const gethConfigs = {
-    shouldUseInProcessGanache: false,
-    rpcUrl: 'http://localhost:8501',
-    shouldUseFakeGasEstimate: false,
-};
-const ganacheConfigs = {
-    shouldUseInProcessGanache: true,
-};
-const providerConfigs = testProvider === ProviderType.Ganache ? ganacheConfigs : gethConfigs;
-
-export const provider = web3Factory.getRpcProvider(providerConfigs);
-const isCoverageEnabled = env.parseBoolean(EnvVars.SolidityCoverage);
-const isProfilerEnabled = env.parseBoolean(EnvVars.SolidityProfiler);
-const isRevertTraceEnabled = env.parseBoolean(EnvVars.SolidityRevertTrace);
-const enabledSubproviderCount = _.filter([isCoverageEnabled, isProfilerEnabled, isRevertTraceEnabled], _.identity)
-    .length;
-if (enabledSubproviderCount > 1) {
-    throw new Error(`Only one of coverage, profiler, or revert trace subproviders can be enabled at a time`);
-}
-if (isCoverageEnabled) {
-    const coverageSubprovider = coverage.getCoverageSubproviderSingleton();
-    prependSubprovider(provider, coverageSubprovider);
-}
-if (isProfilerEnabled) {
-    if (testProvider === ProviderType.Ganache) {
-        logUtils.warn(
-            "Gas costs in Ganache traces are incorrect and we don't recommend using it for profiling. Please switch to Geth",
-        );
-        process.exit(1);
-    }
-    const profilerSubprovider = profiler.getProfilerSubproviderSingleton();
-    logUtils.log(
-        "By default profilerSubprovider is stopped so that you don't get noise from setup code. Don't forget to start it before the code you want to profile and stop it afterwards",
-    );
-    profilerSubprovider.stop();
-    prependSubprovider(provider, profilerSubprovider);
-}
-if (isRevertTraceEnabled) {
-    const revertTraceSubprovider = revertTrace.getRevertTraceSubproviderSingleton();
-    prependSubprovider(provider, revertTraceSubprovider);
-}
-
-export const web3Wrapper = new Web3Wrapper(provider);