update tools deps

rebase
fixed multihop buy through multiplex
2022-02-26 16:01:17 -05:00 · 2022-02-26 15:20:30 -05:00 · 2022-02-26 15:20:30 -05:00 · 2022-02-26 15:20:30 -05:00 · 2022-02-26 15:20:30 -05:00 · 2022-02-26 15:20:30 -05:00
202 changed files with 27301 additions and 15093 deletions
--- a/contracts/erc20/CHANGELOG.json
+++ b/contracts/erc20/CHANGELOG.json
@@ -1,4 +1,13 @@
 [
+    {
+        "timestamp": 1645569128,
+        "version": "3.3.26",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
    {
        "timestamp": 1640364306,
        "version": "3.3.25",
--- a/contracts/erc20/CHANGELOG.md
+++ b/contracts/erc20/CHANGELOG.md
@@ -5,6 +5,10 @@ Edit the package's CHANGELOG.json file only.

 CHANGELOG

+## v3.3.26 - _February 22, 2022_
+
+    * Dependencies updated
+
 ## v3.3.25 - _December 24, 2021_

    * Dependencies updated
--- a/contracts/erc20/package.json
+++ b/contracts/erc20/package.json
@@ -1,6 +1,6 @@
 {
    "name": "@0x/contracts-erc20",
-    "version": "3.3.25",
+    "version": "3.3.26",
    "engines": {
        "node": ">=6.12"
    },
@@ -51,18 +51,18 @@
    },
    "homepage": "https://github.com/0xProject/protocol/tree/main/contracts/tokens",
    "devDependencies": {
-        "@0x/abi-gen": "^5.6.2",
-        "@0x/contracts-gen": "^2.0.40",
-        "@0x/contracts-test-utils": "^5.4.16",
-        "@0x/contracts-utils": "^4.8.6",
-        "@0x/dev-utils": "^4.2.9",
-        "@0x/sol-compiler": "^4.7.5",
+        "@0x/abi-gen": "^5.7.3",
+        "@0x/contracts-gen": "^2.0.44",
+        "@0x/contracts-test-utils": "^5.4.17",
+        "@0x/contracts-utils": "^4.8.7",
+        "@0x/dev-utils": "^4.2.12",
+        "@0x/sol-compiler": "^4.7.9",
        "@0x/ts-doc-gen": "^0.0.28",
        "@0x/tslint-config": "^4.1.4",
-        "@0x/types": "^3.3.4",
-        "@0x/typescript-typings": "^5.2.1",
-        "@0x/utils": "^6.4.4",
-        "@0x/web3-wrapper": "^7.6.0",
+        "@0x/types": "^3.3.5",
+        "@0x/typescript-typings": "^5.2.2",
+        "@0x/utils": "^6.5.1",
+        "@0x/web3-wrapper": "^7.6.3",
        "@types/lodash": "4.14.104",
        "@types/mocha": "^5.2.7",
        "@types/node": "12.12.54",
@@ -70,7 +70,7 @@
        "chai-as-promised": "^7.1.0",
        "chai-bignumber": "^3.0.0",
        "dirty-chai": "^2.0.1",
-        "ethereum-types": "^3.6.0",
+        "ethereum-types": "^3.6.1",
        "lodash": "^4.17.11",
        "make-promises-safe": "^1.1.0",
        "mocha": "^6.2.0",
@@ -82,7 +82,7 @@
        "typescript": "4.2.2"
    },
    "dependencies": {
-        "@0x/base-contract": "^6.4.2",
+        "@0x/base-contract": "^6.4.6",
        "ethers": "~4.0.4"
    },
    "publishConfig": {
--- a/contracts/test-utils/CHANGELOG.json
+++ b/contracts/test-utils/CHANGELOG.json
@@ -1,4 +1,13 @@
 [
+    {
+        "timestamp": 1645569128,
+        "version": "5.4.17",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
    {
        "timestamp": 1640364306,
        "version": "5.4.16",
--- a/contracts/test-utils/CHANGELOG.md
+++ b/contracts/test-utils/CHANGELOG.md
@@ -5,6 +5,10 @@ Edit the package's CHANGELOG.json file only.

 CHANGELOG

+## v5.4.17 - _February 22, 2022_
+
+    * Dependencies updated
+
 ## v5.4.16 - _December 24, 2021_

    * Dependencies updated
--- a/contracts/test-utils/package.json
+++ b/contracts/test-utils/package.json
@@ -1,6 +1,6 @@
 {
    "name": "@0x/contracts-test-utils",
-    "version": "5.4.16",
+    "version": "5.4.17",
    "engines": {
        "node": ">=6.12"
    },
@@ -34,7 +34,7 @@
    },
    "homepage": "https://github.com/0xProject/protocol/tree/main/contracts/test-utils",
    "devDependencies": {
-        "@0x/sol-compiler": "^4.7.5",
+        "@0x/sol-compiler": "^4.7.9",
        "@0x/tslint-config": "^4.1.4",
        "npm-run-all": "^4.1.2",
        "shx": "^0.2.2",
@@ -42,20 +42,20 @@
        "typescript": "4.2.2"
    },
    "dependencies": {
-        "@0x/assert": "^3.0.29",
-        "@0x/base-contract": "^6.4.2",
+        "@0x/assert": "^3.0.32",
+        "@0x/base-contract": "^6.4.6",
        "@0x/contract-addresses": "^6.11.0",
-        "@0x/dev-utils": "^4.2.9",
-        "@0x/json-schemas": "^6.3.0",
+        "@0x/dev-utils": "^4.2.12",
+        "@0x/json-schemas": "^6.4.2",
        "@0x/order-utils": "^10.4.28",
-        "@0x/sol-coverage": "^4.0.39",
-        "@0x/sol-profiler": "^4.1.29",
-        "@0x/sol-trace": "^3.0.39",
-        "@0x/subproviders": "^6.6.0",
-        "@0x/types": "^3.3.4",
-        "@0x/typescript-typings": "^5.2.1",
-        "@0x/utils": "^6.4.4",
-        "@0x/web3-wrapper": "^7.6.0",
+        "@0x/sol-coverage": "^4.0.43",
+        "@0x/sol-profiler": "^4.1.33",
+        "@0x/sol-trace": "^3.0.43",
+        "@0x/subproviders": "^6.6.3",
+        "@0x/types": "^3.3.5",
+        "@0x/typescript-typings": "^5.2.2",
+        "@0x/utils": "^6.5.1",
+        "@0x/web3-wrapper": "^7.6.3",
        "@types/bn.js": "^4.11.0",
        "@types/js-combinatorics": "^0.5.29",
        "@types/lodash": "4.14.104",
@@ -67,7 +67,7 @@
        "chai-bignumber": "^3.0.0",
        "decimal.js": "^10.2.0",
        "dirty-chai": "^2.0.1",
-        "ethereum-types": "^3.6.0",
+        "ethereum-types": "^3.6.1",
        "ethereumjs-util": "^7.0.10",
        "ethers": "~4.0.4",
        "js-combinatorics": "^0.5.3",
--- a/contracts/treasury/CHANGELOG.json
+++ b/contracts/treasury/CHANGELOG.json
@@ -1,4 +1,13 @@
 [
+    {
+        "timestamp": 1645569128,
+        "version": "1.4.9",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
    {
        "timestamp": 1640364306,
        "version": "1.4.8",
--- a/contracts/treasury/CHANGELOG.md
+++ b/contracts/treasury/CHANGELOG.md
@@ -5,6 +5,10 @@ Edit the package's CHANGELOG.json file only.

 CHANGELOG

+## v1.4.9 - _February 22, 2022_
+
+    * Dependencies updated
+
 ## v1.4.8 - _December 24, 2021_

    * Dependencies updated
--- a/contracts/treasury/package.json
+++ b/contracts/treasury/package.json
@@ -1,6 +1,6 @@
 {
    "name": "@0x/contracts-treasury",
-    "version": "1.4.8",
+    "version": "1.4.9",
    "engines": {
        "node": ">=6.12"
    },
@@ -46,14 +46,14 @@
    },
    "homepage": "https://github.com/0xProject/protocol/tree/main/contracts/treasury",
    "devDependencies": {
-        "@0x/abi-gen": "^5.6.2",
+        "@0x/abi-gen": "^5.7.3",
        "@0x/contract-addresses": "^6.11.0",
        "@0x/contracts-asset-proxy": "^3.7.19",
-        "@0x/contracts-erc20": "^3.3.25",
-        "@0x/contracts-gen": "^2.0.40",
+        "@0x/contracts-erc20": "^3.3.26",
+        "@0x/contracts-gen": "^2.0.44",
        "@0x/contracts-staking": "^2.0.45",
-        "@0x/contracts-test-utils": "^5.4.16",
-        "@0x/sol-compiler": "^4.7.5",
+        "@0x/contracts-test-utils": "^5.4.17",
+        "@0x/sol-compiler": "^4.7.9",
        "@0x/ts-doc-gen": "^0.0.28",
        "@0x/tslint-config": "^4.1.4",
        "@types/isomorphic-fetch": "^0.0.35",
@@ -72,14 +72,14 @@
        "typescript": "4.2.2"
    },
    "dependencies": {
-        "@0x/base-contract": "^6.4.2",
-        "@0x/protocol-utils": "^1.10.1",
-        "@0x/subproviders": "^6.6.0",
-        "@0x/types": "^3.3.4",
-        "@0x/typescript-typings": "^5.2.1",
-        "@0x/utils": "^6.4.4",
-        "@0x/web3-wrapper": "^7.6.0",
-        "ethereum-types": "^3.6.0",
+        "@0x/base-contract": "^6.4.6",
+        "@0x/protocol-utils": "^1.11.0",
+        "@0x/subproviders": "^6.6.3",
+        "@0x/types": "^3.3.5",
+        "@0x/typescript-typings": "^5.2.2",
+        "@0x/utils": "^6.5.1",
+        "@0x/web3-wrapper": "^7.6.3",
+        "ethereum-types": "^3.6.1",
        "ethereumjs-util": "^7.0.10"
    },
    "publishConfig": {
--- a/contracts/utils/CHANGELOG.json
+++ b/contracts/utils/CHANGELOG.json
@@ -1,4 +1,13 @@
 [
+    {
+        "timestamp": 1645569128,
+        "version": "4.8.7",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
    {
        "timestamp": 1640364306,
        "version": "4.8.6",
--- a/contracts/utils/CHANGELOG.md
+++ b/contracts/utils/CHANGELOG.md
@@ -5,6 +5,10 @@ Edit the package's CHANGELOG.json file only.

 CHANGELOG

+## v4.8.7 - _February 22, 2022_
+
+    * Dependencies updated
+
 ## v4.8.6 - _December 24, 2021_

    * Dependencies updated
--- a/contracts/utils/package.json
+++ b/contracts/utils/package.json
@@ -1,6 +1,6 @@
 {
    "name": "@0x/contracts-utils",
-    "version": "4.8.6",
+    "version": "4.8.7",
    "engines": {
        "node": ">=6.12"
    },
@@ -50,15 +50,15 @@
    },
    "homepage": "https://github.com/0xProject/protocol/tree/main/contracts/utils",
    "devDependencies": {
-        "@0x/abi-gen": "^5.6.2",
-        "@0x/contracts-gen": "^2.0.40",
-        "@0x/contracts-test-utils": "^5.4.16",
-        "@0x/dev-utils": "^4.2.9",
+        "@0x/abi-gen": "^5.7.3",
+        "@0x/contracts-gen": "^2.0.44",
+        "@0x/contracts-test-utils": "^5.4.17",
+        "@0x/dev-utils": "^4.2.12",
        "@0x/order-utils": "^10.4.28",
-        "@0x/sol-compiler": "^4.7.5",
+        "@0x/sol-compiler": "^4.7.9",
        "@0x/tslint-config": "^4.1.4",
-        "@0x/types": "^3.3.4",
-        "@0x/web3-wrapper": "^7.6.0",
+        "@0x/types": "^3.3.5",
+        "@0x/web3-wrapper": "^7.6.3",
        "@types/bn.js": "^4.11.0",
        "@types/lodash": "4.14.104",
        "@types/mocha": "^5.2.7",
@@ -79,11 +79,11 @@
        "typescript": "4.2.2"
    },
    "dependencies": {
-        "@0x/base-contract": "^6.4.2",
-        "@0x/typescript-typings": "^5.2.1",
-        "@0x/utils": "^6.4.4",
+        "@0x/base-contract": "^6.4.6",
+        "@0x/typescript-typings": "^5.2.2",
+        "@0x/utils": "^6.5.1",
        "bn.js": "^4.11.8",
-        "ethereum-types": "^3.6.0"
+        "ethereum-types": "^3.6.1"
    },
    "publishConfig": {
        "access": "public"
--- a/contracts/zero-ex/CHANGELOG.json
+++ b/contracts/zero-ex/CHANGELOG.json
@@ -1,4 +1,14 @@
 [
+    {
+        "version": "0.31.0",
+        "changes": [
+            {
+                "note": "Add ERC721OrdersFeature, ERC1155OrdersFeature, and ERC165Feature",
+                "pr": 429
+            }
+        ],
+        "timestamp": 1645569128
+    },
    {
        "timestamp": 1640364306,
        "version": "0.30.1",
--- a/contracts/zero-ex/CHANGELOG.md
+++ b/contracts/zero-ex/CHANGELOG.md
@@ -5,6 +5,10 @@ Edit the package's CHANGELOG.json file only.

 CHANGELOG

+## v0.31.0 - _February 22, 2022_
+
+    * Add ERC721OrdersFeature, ERC1155OrdersFeature, and ERC165Feature (#429)
+
 ## v0.30.1 - _December 24, 2021_

    * Dependencies updated
--- a/contracts/zero-ex/contracts/src/IZeroEx.sol
+++ b/contracts/zero-ex/contracts/src/IZeroEx.sol
@@ -34,6 +34,9 @@ import "./features/interfaces/IBatchFillNativeOrdersFeature.sol";
 import "./features/interfaces/IMultiplexFeature.sol";
 import "./features/interfaces/IOtcOrdersFeature.sol";
 import "./features/interfaces/IFundRecoveryFeature.sol";
+import "./features/interfaces/IERC721OrdersFeature.sol";
+import "./features/interfaces/IERC1155OrdersFeature.sol";
+import "./features/interfaces/IERC165Feature.sol";


 /// @dev Interface for a fully featured Exchange Proxy.
@@ -50,7 +53,10 @@ interface IZeroEx is
    IBatchFillNativeOrdersFeature,
    IMultiplexFeature,
    IOtcOrdersFeature,
-    IFundRecoveryFeature
+    IFundRecoveryFeature,
+    IERC721OrdersFeature,
+    IERC1155OrdersFeature,
+    IERC165Feature
 {
    // solhint-disable state-visibility

--- a/contracts/zero-ex/contracts/src/errors/LibNFTOrdersRichErrors.sol
+++ b/contracts/zero-ex/contracts/src/errors/LibNFTOrdersRichErrors.sol
@@ -0,0 +1,229 @@
+// SPDX-License-Identifier: Apache-2.0
+/*
+
+  Copyright 2021 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 ^0.6.5;
+
+
+library LibNFTOrdersRichErrors {
+
+    // solhint-disable func-name-mixedcase
+
+    function OverspentEthError(
+        uint256 ethSpent,
+        uint256 ethAvailable
+    )
+        internal
+        pure
+        returns (bytes memory)
+    {
+        return abi.encodeWithSelector(
+            bytes4(keccak256("OverspentEthError(uint256,uint256)")),
+            ethSpent,
+            ethAvailable
+        );
+    }
+
+    function InsufficientEthError(
+        uint256 ethAvailable,
+        uint256 orderAmount
+    )
+        internal
+        pure
+        returns (bytes memory)
+    {
+        return abi.encodeWithSelector(
+            bytes4(keccak256("InsufficientEthError(uint256,uint256)")),
+            ethAvailable,
+            orderAmount
+        );
+    }
+
+    function ERC721TokenMismatchError(
+        address token1,
+        address token2
+    )
+        internal
+        pure
+        returns (bytes memory)
+    {
+        return abi.encodeWithSelector(
+            bytes4(keccak256("ERC721TokenMismatchError(address,address)")),
+            token1,
+            token2
+        );
+    }
+
+    function ERC1155TokenMismatchError(
+        address token1,
+        address token2
+    )
+        internal
+        pure
+        returns (bytes memory)
+    {
+        return abi.encodeWithSelector(
+            bytes4(keccak256("ERC1155TokenMismatchError(address,address)")),
+            token1,
+            token2
+        );
+    }
+
+    function ERC20TokenMismatchError(
+        address token1,
+        address token2
+    )
+        internal
+        pure
+        returns (bytes memory)
+    {
+        return abi.encodeWithSelector(
+            bytes4(keccak256("ERC20TokenMismatchError(address,address)")),
+            token1,
+            token2
+        );
+    }
+
+    function NegativeSpreadError(
+        uint256 sellOrderAmount,
+        uint256 buyOrderAmount
+    )
+        internal
+        pure
+        returns (bytes memory)
+    {
+        return abi.encodeWithSelector(
+            bytes4(keccak256("NegativeSpreadError(uint256,uint256)")),
+            sellOrderAmount,
+            buyOrderAmount
+        );
+    }
+
+    function SellOrderFeesExceedSpreadError(
+        uint256 sellOrderFees,
+        uint256 spread
+    )
+        internal
+        pure
+        returns (bytes memory)
+    {
+        return abi.encodeWithSelector(
+            bytes4(keccak256("SellOrderFeesExceedSpreadError(uint256,uint256)")),
+            sellOrderFees,
+            spread
+        );
+    }
+
+    function OnlyTakerError(
+        address sender,
+        address taker
+    )
+        internal
+        pure
+        returns (bytes memory)
+    {
+        return abi.encodeWithSelector(
+            bytes4(keccak256("OnlyTakerError(address,address)")),
+            sender,
+            taker
+        );
+    }
+
+    function InvalidSignerError(
+        address maker,
+        address signer
+    )
+        internal
+        pure
+        returns (bytes memory)
+    {
+        return abi.encodeWithSelector(
+            bytes4(keccak256("InvalidSignerError(address,address)")),
+            maker,
+            signer
+        );
+    }
+
+    function OrderNotFillableError(
+        address maker,
+        uint256 nonce,
+        uint8 orderStatus
+    )
+        internal
+        pure
+        returns (bytes memory)
+    {
+        return abi.encodeWithSelector(
+            bytes4(keccak256("OrderNotFillableError(address,uint256,uint8)")),
+            maker,
+            nonce,
+            orderStatus
+        );
+    }
+
+    function TokenIdMismatchError(
+        uint256 tokenId,
+        uint256 orderTokenId
+    )
+        internal
+        pure
+        returns (bytes memory)
+    {
+        return abi.encodeWithSelector(
+            bytes4(keccak256("TokenIdMismatchError(uint256,uint256)")),
+            tokenId,
+            orderTokenId
+        );
+    }
+
+    function PropertyValidationFailedError(
+        address propertyValidator,
+        address token,
+        uint256 tokenId,
+        bytes memory propertyData,
+        bytes memory errorData
+    )
+        internal
+        pure
+        returns (bytes memory)
+    {
+        return abi.encodeWithSelector(
+            bytes4(keccak256("PropertyValidationFailedError(address,address,uint256,bytes,bytes)")),
+            propertyValidator,
+            token,
+            tokenId,
+            propertyData,
+            errorData
+        );
+    }
+
+    function ExceedsRemainingOrderAmount(
+        uint128 remainingOrderAmount,
+        uint128 fillAmount
+    )
+        internal
+        pure
+        returns (bytes memory)
+    {
+        return abi.encodeWithSelector(
+            bytes4(keccak256("ExceedsRemainingOrderAmount(uint128,uint128)")),
+            remainingOrderAmount,
+            fillAmount
+        );
+    }
+}
--- a/contracts/zero-ex/contracts/src/features/ERC165Feature.sol
+++ b/contracts/zero-ex/contracts/src/features/ERC165Feature.sol
@@ -0,0 +1,51 @@
+// SPDX-License-Identifier: Apache-2.0
+/*
+
+  Copyright 2022 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 ^0.6;
+pragma experimental ABIEncoderV2;
+
+import "../fixins/FixinCommon.sol";
+import "./interfaces/IFeature.sol";
+
+
+/// @dev Implements the ERC165 `supportsInterface` function
+contract ERC165Feature is
+    IFeature,
+    FixinCommon
+{
+    /// @dev Name of this feature.
+    string public constant override FEATURE_NAME = "ERC165";
+    /// @dev Version of this feature.
+    uint256 public immutable override FEATURE_VERSION = _encodeVersion(1, 0, 0);
+
+    /// @dev Indicates whether the 0x Exchange Proxy implements a particular
+    ///      ERC165 interface. This function should use at most 30,000 gas.
+    /// @param interfaceId The interface identifier, as specified in ERC165.
+    /// @return isSupported Whether the given interface is supported by the
+    ///         0x Exchange Proxy.
+    function supportInterface(bytes4 interfaceId)
+        external
+        pure
+        returns (bool isSupported)
+    {
+        return interfaceId == 0x01ffc9a7 || // ERC-165 support
+               interfaceId == 0x150b7a02 || // ERC-721 `ERC721TokenReceiver` support
+               interfaceId == 0x4e2312e0;   // ERC-1155 `ERC1155TokenReceiver` support
+    }
+}
--- a/contracts/zero-ex/contracts/src/features/OtcOrdersFeature.sol
+++ b/contracts/zero-ex/contracts/src/features/OtcOrdersFeature.sol
@@ -311,7 +311,7 @@ contract OtcOrdersFeature is
        // Unwrap WETH
        WETH.withdraw(order.makerAmount);
        // Transfer ETH to taker
-        _transferEth(taker, order.makerAmount);
+        _transferEth(payable(taker), order.makerAmount);

        emit OtcOrderFilled(
            orderInfo.orderHash,
@@ -622,16 +622,4 @@ contract OtcOrdersFeature is
            [txOrigin]
            [nonceBucket];
    }
-
-    function _transferEth(address recipient, uint256 amount)
-        private
-    {
-        // Transfer ETH to recipient
-        (bool success, bytes memory revertData) =
-            recipient.call{value: amount}("");
-        // Revert on failure
-        if (!success) {
-            revertData.rrevert();
-        }
-    }
 }
--- a/contracts/zero-ex/contracts/src/features/interfaces/IERC1155OrdersFeature.sol
+++ b/contracts/zero-ex/contracts/src/features/interfaces/IERC1155OrdersFeature.sol
@@ -0,0 +1,242 @@
+// SPDX-License-Identifier: Apache-2.0
+/*
+
+  Copyright 2021 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 ^0.6;
+pragma experimental ABIEncoderV2;
+
+import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
+import "../libs/LibNFTOrder.sol";
+import "../libs/LibSignature.sol";
+import "../../vendor/IERC1155Token.sol";
+
+
+/// @dev Feature for interacting with ERC1155 orders.
+interface IERC1155OrdersFeature {
+
+    /// @dev Emitted whenever an `ERC1155Order` is filled.
+    /// @param direction Whether the order is selling or
+    ///        buying the ERC1155 token.
+    /// @param maker The maker of the order.
+    /// @param taker The taker of the order.
+    /// @param nonce The unique maker nonce in the order.
+    /// @param erc20Token The address of the ERC20 token.
+    /// @param erc20FillAmount The amount of ERC20 token filled.
+    /// @param erc1155Token The address of the ERC1155 token.
+    /// @param erc1155TokenId The ID of the ERC1155 asset.
+    /// @param erc1155FillAmount The amount of ERC1155 asset filled.
+    /// @param matcher Currently unused.
+    event ERC1155OrderFilled(
+        LibNFTOrder.TradeDirection direction,
+        address maker,
+        address taker,
+        uint256 nonce,
+        IERC20TokenV06 erc20Token,
+        uint256 erc20FillAmount,
+        IERC1155Token erc1155Token,
+        uint256 erc1155TokenId,
+        uint128 erc1155FillAmount,
+        address matcher
+    );
+
+    /// @dev Emitted whenever an `ERC1155Order` is cancelled.
+    /// @param maker The maker of the order.
+    /// @param nonce The nonce of the order that was cancelled.
+    event ERC1155OrderCancelled(
+        address maker,
+        uint256 nonce
+    );
+
+    /// @dev Emitted when an `ERC1155Order` is pre-signed.
+    ///      Contains all the fields of the order.
+    event ERC1155OrderPreSigned(
+        LibNFTOrder.TradeDirection direction,
+        address maker,
+        address taker,
+        uint256 expiry,
+        uint256 nonce,
+        IERC20TokenV06 erc20Token,
+        uint256 erc20TokenAmount,
+        LibNFTOrder.Fee[] fees,
+        IERC1155Token erc1155Token,
+        uint256 erc1155TokenId,
+        LibNFTOrder.Property[] erc1155TokenProperties,
+        uint128 erc1155TokenAmount
+    );
+
+    /// @dev Sells an ERC1155 asset to fill the given order.
+    /// @param buyOrder The ERC1155 buy order.
+    /// @param signature The order signature from the maker.
+    /// @param erc1155TokenId The ID of the ERC1155 asset being
+    ///        sold. If the given order specifies properties,
+    ///        the asset must satisfy those properties. Otherwise,
+    ///        it must equal the tokenId in the order.
+    /// @param erc1155SellAmount The amount of the ERC1155 asset
+    ///        to sell.
+    /// @param unwrapNativeToken If this parameter is true and the
+    ///        ERC20 token of the order is e.g. WETH, unwraps the
+    ///        token before transferring it to the taker.
+    /// @param callbackData If this parameter is non-zero, invokes
+    ///        `zeroExERC1155OrderCallback` on `msg.sender` after
+    ///        the ERC20 tokens have been transferred to `msg.sender`
+    ///        but before transferring the ERC1155 asset to the buyer.
+    function sellERC1155(
+        LibNFTOrder.ERC1155Order calldata buyOrder,
+        LibSignature.Signature calldata signature,
+        uint256 erc1155TokenId,
+        uint128 erc1155SellAmount,
+        bool unwrapNativeToken,
+        bytes calldata callbackData
+    )
+        external;
+
+    /// @dev Buys an ERC1155 asset by filling the given order.
+    /// @param sellOrder The ERC1155 sell order.
+    /// @param signature The order signature.
+    /// @param erc1155BuyAmount The amount of the ERC1155 asset
+    ///        to buy.
+    /// @param callbackData If this parameter is non-zero, invokes
+    ///        `zeroExERC1155OrderCallback` on `msg.sender` after
+    ///        the ERC1155 asset has been transferred to `msg.sender`
+    ///        but before transferring the ERC20 tokens to the seller.
+    ///        Native tokens acquired during the callback can be used
+    ///        to fill the order.
+    function buyERC1155(
+        LibNFTOrder.ERC1155Order calldata sellOrder,
+        LibSignature.Signature calldata signature,
+        uint128 erc1155BuyAmount,
+        bytes calldata callbackData
+    )
+        external
+        payable;
+
+    /// @dev Cancel a single ERC1155 order by its nonce. The caller
+    ///      should be the maker of the order. Silently succeeds if
+    ///      an order with the same nonce has already been filled or
+    ///      cancelled.
+    /// @param orderNonce The order nonce.
+    function cancelERC1155Order(uint256 orderNonce)
+        external;
+
+    /// @dev Cancel multiple ERC1155 orders by their nonces. The caller
+    ///      should be the maker of the orders. Silently succeeds if
+    ///      an order with the same nonce has already been filled or
+    ///      cancelled.
+    /// @param orderNonces The order nonces.
+    function batchCancelERC1155Orders(uint256[] calldata orderNonces)
+        external;
+
+    /// @dev Buys multiple ERC1155 assets by filling the
+    ///      given orders.
+    /// @param sellOrders The ERC1155 sell orders.
+    /// @param signatures The order signatures.
+    /// @param erc1155TokenAmounts The amounts of the ERC1155 assets
+    ///        to buy for each order.
+    /// @param callbackData The data (if any) to pass to the taker
+    ///        callback for each order. Refer to the `callbackData`
+    ///        parameter to for `buyERC1155`.
+    /// @param revertIfIncomplete If true, reverts if this
+    ///        function fails to fill any individual order.
+    /// @return successes An array of booleans corresponding to whether
+    ///         each order in `orders` was successfully filled.
+    function batchBuyERC1155s(
+        LibNFTOrder.ERC1155Order[] calldata sellOrders,
+        LibSignature.Signature[] calldata signatures,
+        uint128[] calldata erc1155TokenAmounts,
+        bytes[] calldata callbackData,
+        bool revertIfIncomplete
+    )
+        external
+        payable
+        returns (bool[] memory successes);
+
+    /// @dev Callback for the ERC1155 `safeTransferFrom` function.
+    ///      This callback can be used to sell an ERC1155 asset if
+    ///      a valid ERC1155 order, signature and `unwrapNativeToken`
+    ///      are encoded in `data`. This allows takers to sell their
+    ///      ERC1155 asset without first calling `setApprovalForAll`.
+    /// @param operator The address which called `safeTransferFrom`.
+    /// @param from The address which previously owned the token.
+    /// @param tokenId The ID of the asset being transferred.
+    /// @param value The amount being transferred.
+    /// @param data Additional data with no specified format. If a
+    ///        valid ERC1155 order, signature and `unwrapNativeToken`
+    ///        are encoded in `data`, this function will try to fill
+    ///        the order using the received asset.
+    /// @return success The selector of this function (0xf23a6e61),
+    ///         indicating that the callback succeeded.
+    function onERC1155Received(
+        address operator,
+        address from,
+        uint256 tokenId,
+        uint256 value,
+        bytes calldata data
+    )
+        external
+        returns (bytes4 success);
+
+    /// @dev Approves an ERC1155 order on-chain. After pre-signing
+    ///      the order, the `PRESIGNED` signature type will become
+    ///      valid for that order and signer.
+    /// @param order An ERC1155 order.
+    function preSignERC1155Order(LibNFTOrder.ERC1155Order calldata order)
+        external;
+
+    /// @dev Checks whether the given signature is valid for the
+    ///      the given ERC1155 order. Reverts if not.
+    /// @param order The ERC1155 order.
+    /// @param signature The signature to validate.
+    function validateERC1155OrderSignature(
+        LibNFTOrder.ERC1155Order calldata order,
+        LibSignature.Signature calldata signature
+    )
+        external
+        view;
+
+    /// @dev If the given order is buying an ERC1155 asset, checks
+    ///      whether or not the given token ID satisfies the required
+    ///      properties specified in the order. If the order does not
+    ///      specify any properties, this function instead checks
+    ///      whether the given token ID matches the ID in the order.
+    ///      Reverts if any checks fail, or if the order is selling
+    ///      an ERC1155 asset.
+    /// @param order The ERC1155 order.
+    /// @param erc1155TokenId The ID of the ERC1155 asset.
+    function validateERC1155OrderProperties(
+        LibNFTOrder.ERC1155Order calldata order,
+        uint256 erc1155TokenId
+    )
+        external
+        view;
+
+    /// @dev Get the order info for an ERC1155 order.
+    /// @param order The ERC1155 order.
+    /// @return orderInfo Infor about the order.
+    function getERC1155OrderInfo(LibNFTOrder.ERC1155Order calldata order)
+        external
+        view
+        returns (LibNFTOrder.OrderInfo memory orderInfo);
+
+    /// @dev Get the EIP-712 hash of an ERC1155 order.
+    /// @param order The ERC1155 order.
+    /// @return orderHash The order hash.
+    function getERC1155OrderHash(LibNFTOrder.ERC1155Order calldata order)
+        external
+        view
+        returns (bytes32 orderHash);
+}
--- a/contracts/zero-ex/contracts/src/features/interfaces/IERC165Feature.sol
+++ b/contracts/zero-ex/contracts/src/features/interfaces/IERC165Feature.sol
@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: Apache-2.0
 /*

-  Copyright 2020 ZeroEx Intl.
+  Copyright 2022 ZeroEx Intl.

  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
@@ -18,26 +18,19 @@
 */

 pragma solidity ^0.6;
+pragma experimental ABIEncoderV2;


-interface IShell {
+/// @dev Implements the ERC165 `supportsInterface` function
+interface IERC165Feature {

-    function viewOriginSwap (
-        address from,
-        address to,
-        uint256 fromAmount
-    )
+    /// @dev Indicates whether the 0x Exchange Proxy implements a particular
+    ///      ERC165 interface. This function should use at most 30,000 gas.
+    /// @param interfaceId The interface identifier, as specified in ERC165.
+    /// @return isSupported Whether the given interface is supported by the
+    ///         0x Exchange Proxy.
+    function supportInterface(bytes4 interfaceId)
        external
-        view
-        returns (uint256 toAmount);
-
-    function viewTargetSwap (
-        address from,
-        address to,
-        uint256 toAmount
-    )
-        external
-        view
-        returns (uint256 fromAmount);
+        pure
+        returns (bool isSupported);
 }
-
--- a/contracts/zero-ex/contracts/src/features/interfaces/IERC721OrdersFeature.sol
+++ b/contracts/zero-ex/contracts/src/features/interfaces/IERC721OrdersFeature.sol
@@ -0,0 +1,286 @@
+// SPDX-License-Identifier: Apache-2.0
+/*
+
+  Copyright 2021 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 ^0.6;
+pragma experimental ABIEncoderV2;
+
+import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
+import "../libs/LibNFTOrder.sol";
+import "../libs/LibSignature.sol";
+import "../../vendor/IERC721Token.sol";
+
+
+/// @dev Feature for interacting with ERC721 orders.
+interface IERC721OrdersFeature {
+
+    /// @dev Emitted whenever an `ERC721Order` is filled.
+    /// @param direction Whether the order is selling or
+    ///        buying the ERC721 token.
+    /// @param maker The maker of the order.
+    /// @param taker The taker of the order.
+    /// @param nonce The unique maker nonce in the order.
+    /// @param erc20Token The address of the ERC20 token.
+    /// @param erc20TokenAmount The amount of ERC20 token
+    ///        to sell or buy.
+    /// @param erc721Token The address of the ERC721 token.
+    /// @param erc721TokenId The ID of the ERC721 asset.
+    /// @param matcher If this order was matched with another using `matchERC721Orders()`,
+    ///                this will be the address of the caller. If not, this will be `address(0)`.
+    event ERC721OrderFilled(
+        LibNFTOrder.TradeDirection direction,
+        address maker,
+        address taker,
+        uint256 nonce,
+        IERC20TokenV06 erc20Token,
+        uint256 erc20TokenAmount,
+        IERC721Token erc721Token,
+        uint256 erc721TokenId,
+        address matcher
+    );
+
+    /// @dev Emitted whenever an `ERC721Order` is cancelled.
+    /// @param maker The maker of the order.
+    /// @param nonce The nonce of the order that was cancelled.
+    event ERC721OrderCancelled(
+        address maker,
+        uint256 nonce
+    );
+
+    /// @dev Emitted when an `ERC721Order` is pre-signed.
+    ///      Contains all the fields of the order.
+    event ERC721OrderPreSigned(
+        LibNFTOrder.TradeDirection direction,
+        address maker,
+        address taker,
+        uint256 expiry,
+        uint256 nonce,
+        IERC20TokenV06 erc20Token,
+        uint256 erc20TokenAmount,
+        LibNFTOrder.Fee[] fees,
+        IERC721Token erc721Token,
+        uint256 erc721TokenId,
+        LibNFTOrder.Property[] erc721TokenProperties
+    );
+
+    /// @dev Sells an ERC721 asset to fill the given order.
+    /// @param buyOrder The ERC721 buy order.
+    /// @param signature The order signature from the maker.
+    /// @param erc721TokenId The ID of the ERC721 asset being
+    ///        sold. If the given order specifies properties,
+    ///        the asset must satisfy those properties. Otherwise,
+    ///        it must equal the tokenId in the order.
+    /// @param unwrapNativeToken If this parameter is true and the
+    ///        ERC20 token of the order is e.g. WETH, unwraps the
+    ///        token before transferring it to the taker.
+    /// @param callbackData If this parameter is non-zero, invokes
+    ///        `zeroExERC721OrderCallback` on `msg.sender` after
+    ///        the ERC20 tokens have been transferred to `msg.sender`
+    ///        but before transferring the ERC721 asset to the buyer.
+    function sellERC721(
+        LibNFTOrder.ERC721Order calldata buyOrder,
+        LibSignature.Signature calldata signature,
+        uint256 erc721TokenId,
+        bool unwrapNativeToken,
+        bytes calldata callbackData
+    )
+        external;
+
+    /// @dev Buys an ERC721 asset by filling the given order.
+    /// @param sellOrder The ERC721 sell order.
+    /// @param signature The order signature.
+    /// @param callbackData If this parameter is non-zero, invokes
+    ///        `zeroExERC721OrderCallback` on `msg.sender` after
+    ///        the ERC721 asset has been transferred to `msg.sender`
+    ///        but before transferring the ERC20 tokens to the seller.
+    ///        Native tokens acquired during the callback can be used
+    ///        to fill the order.
+    function buyERC721(
+        LibNFTOrder.ERC721Order calldata sellOrder,
+        LibSignature.Signature calldata signature,
+        bytes calldata callbackData
+    )
+        external
+        payable;
+
+    /// @dev Cancel a single ERC721 order by its nonce. The caller
+    ///      should be the maker of the order. Silently succeeds if
+    ///      an order with the same nonce has already been filled or
+    ///      cancelled.
+    /// @param orderNonce The order nonce.
+    function cancelERC721Order(uint256 orderNonce)
+        external;
+
+    /// @dev Cancel multiple ERC721 orders by their nonces. The caller
+    ///      should be the maker of the orders. Silently succeeds if
+    ///      an order with the same nonce has already been filled or
+    ///      cancelled.
+    /// @param orderNonces The order nonces.
+    function batchCancelERC721Orders(uint256[] calldata orderNonces)
+        external;
+
+    /// @dev Buys multiple ERC721 assets by filling the
+    ///      given orders.
+    /// @param sellOrders The ERC721 sell orders.
+    /// @param signatures The order signatures.
+    /// @param callbackData The data (if any) to pass to the taker
+    ///        callback for each order. Refer to the `callbackData`
+    ///        parameter to for `buyERC721`.
+    /// @param revertIfIncomplete If true, reverts if this
+    ///        function fails to fill any individual order.
+    /// @return successes An array of booleans corresponding to whether
+    ///         each order in `orders` was successfully filled.
+    function batchBuyERC721s(
+        LibNFTOrder.ERC721Order[] calldata sellOrders,
+        LibSignature.Signature[] calldata signatures,
+        bytes[] calldata callbackData,
+        bool revertIfIncomplete
+    )
+        external
+        payable
+        returns (bool[] memory successes);
+
+    /// @dev Matches a pair of complementary orders that have
+    ///      a non-negative spread. Each order is filled at
+    ///      their respective price, and the matcher receives
+    ///      a profit denominated in the ERC20 token.
+    /// @param sellOrder Order selling an ERC721 asset.
+    /// @param buyOrder Order buying an ERC721 asset.
+    /// @param sellOrderSignature Signature for the sell order.
+    /// @param buyOrderSignature Signature for the buy order.
+    /// @return profit The amount of profit earned by the caller
+    ///         of this function (denominated in the ERC20 token
+    ///         of the matched orders).
+    function matchERC721Orders(
+        LibNFTOrder.ERC721Order calldata sellOrder,
+        LibNFTOrder.ERC721Order calldata buyOrder,
+        LibSignature.Signature calldata sellOrderSignature,
+        LibSignature.Signature calldata buyOrderSignature
+    )
+        external
+        returns (uint256 profit);
+
+    /// @dev Matches pairs of complementary orders that have
+    ///      non-negative spreads. Each order is filled at
+    ///      their respective price, and the matcher receives
+    ///      a profit denominated in the ERC20 token.
+    /// @param sellOrders Orders selling ERC721 assets.
+    /// @param buyOrders Orders buying ERC721 assets.
+    /// @param sellOrderSignatures Signatures for the sell orders.
+    /// @param buyOrderSignatures Signatures for the buy orders.
+    /// @return profits The amount of profit earned by the caller
+    ///         of this function for each pair of matched orders
+    ///         (denominated in the ERC20 token of the order pair).
+    /// @return successes An array of booleans corresponding to
+    ///         whether each pair of orders was successfully matched.
+    function batchMatchERC721Orders(
+        LibNFTOrder.ERC721Order[] calldata sellOrders,
+        LibNFTOrder.ERC721Order[] calldata buyOrders,
+        LibSignature.Signature[] calldata sellOrderSignatures,
+        LibSignature.Signature[] calldata buyOrderSignatures
+    )
+        external
+        returns (uint256[] memory profits, bool[] memory successes);
+
+    /// @dev Callback for the ERC721 `safeTransferFrom` function.
+    ///      This callback can be used to sell an ERC721 asset if
+    ///      a valid ERC721 order, signature and `unwrapNativeToken`
+    ///      are encoded in `data`. This allows takers to sell their
+    ///      ERC721 asset without first calling `setApprovalForAll`.
+    /// @param operator The address which called `safeTransferFrom`.
+    /// @param from The address which previously owned the token.
+    /// @param tokenId The ID of the asset being transferred.
+    /// @param data Additional data with no specified format. If a
+    ///        valid ERC721 order, signature and `unwrapNativeToken`
+    ///        are encoded in `data`, this function will try to fill
+    ///        the order using the received asset.
+    /// @return success The selector of this function (0x150b7a02),
+    ///         indicating that the callback succeeded.
+    function onERC721Received(
+        address operator,
+        address from,
+        uint256 tokenId,
+        bytes calldata data
+    )
+        external
+        returns (bytes4 success);
+
+    /// @dev Approves an ERC721 order on-chain. After pre-signing
+    ///      the order, the `PRESIGNED` signature type will become
+    ///      valid for that order and signer.
+    /// @param order An ERC721 order.
+    function preSignERC721Order(LibNFTOrder.ERC721Order calldata order)
+        external;
+
+    /// @dev Checks whether the given signature is valid for the
+    ///      the given ERC721 order. Reverts if not.
+    /// @param order The ERC721 order.
+    /// @param signature The signature to validate.
+    function validateERC721OrderSignature(
+        LibNFTOrder.ERC721Order calldata order,
+        LibSignature.Signature calldata signature
+    )
+        external
+        view;
+
+    /// @dev If the given order is buying an ERC721 asset, checks
+    ///      whether or not the given token ID satisfies the required
+    ///      properties specified in the order. If the order does not
+    ///      specify any properties, this function instead checks
+    ///      whether the given token ID matches the ID in the order.
+    ///      Reverts if any checks fail, or if the order is selling
+    ///      an ERC721 asset.
+    /// @param order The ERC721 order.
+    /// @param erc721TokenId The ID of the ERC721 asset.
+    function validateERC721OrderProperties(
+        LibNFTOrder.ERC721Order calldata order,
+        uint256 erc721TokenId
+    )
+        external
+        view;
+
+    /// @dev Get the current status of an ERC721 order.
+    /// @param order The ERC721 order.
+    /// @return status The status of the order.
+    function getERC721OrderStatus(LibNFTOrder.ERC721Order calldata order)
+        external
+        view
+        returns (LibNFTOrder.OrderStatus status);
+
+    /// @dev Get the EIP-712 hash of an ERC721 order.
+    /// @param order The ERC721 order.
+    /// @return orderHash The order hash.
+    function getERC721OrderHash(LibNFTOrder.ERC721Order calldata order)
+        external
+        view
+        returns (bytes32 orderHash);
+
+    /// @dev Get the order status bit vector for the given
+    ///      maker address and nonce range.
+    /// @param maker The maker of the order.
+    /// @param nonceRange Order status bit vectors are indexed
+    ///        by maker address and the upper 248 bits of the
+    ///        order nonce. We define `nonceRange` to be these
+    ///        248 bits.
+    /// @return bitVector The order status bit vector for the
+    ///         given maker and nonce range.
+    function getERC721OrderStatusBitVector(address maker, uint248 nonceRange)
+        external
+        view
+        returns (uint256 bitVector);
+}
--- a/contracts/zero-ex/contracts/src/features/libs/LibNFTOrder.sol
+++ b/contracts/zero-ex/contracts/src/features/libs/LibNFTOrder.sol
@@ -0,0 +1,459 @@
+// SPDX-License-Identifier: Apache-2.0
+/*
+
+  Copyright 2021 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 ^0.6;
+pragma experimental ABIEncoderV2;
+
+import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
+import "../../vendor/IERC1155Token.sol";
+import "../../vendor/IERC721Token.sol";
+import "../../vendor/IPropertyValidator.sol";
+
+
+/// @dev A library for common NFT order operations.
+library LibNFTOrder {
+
+    enum OrderStatus {
+        INVALID,
+        FILLABLE,
+        UNFILLABLE,
+        EXPIRED
+    }
+
+    enum TradeDirection {
+        SELL_NFT,
+        BUY_NFT
+    }
+
+    struct Property {
+        IPropertyValidator propertyValidator;
+        bytes propertyData;
+    }
+
+    struct Fee {
+        address recipient;
+        uint256 amount;
+        bytes feeData;
+    }
+
+    // "Base struct" for ERC721Order and ERC1155, used
+    // by the abstract contract `NFTOrders`.
+    struct NFTOrder {
+        TradeDirection direction;
+        address maker;
+        address taker;
+        uint256 expiry;
+        uint256 nonce;
+        IERC20TokenV06 erc20Token;
+        uint256 erc20TokenAmount;
+        Fee[] fees;
+        address nft;
+        uint256 nftId;
+        Property[] nftProperties;
+    }
+
+    // All fields align with those of NFTOrder
+    struct ERC721Order {
+        TradeDirection direction;
+        address maker;
+        address taker;
+        uint256 expiry;
+        uint256 nonce;
+        IERC20TokenV06 erc20Token;
+        uint256 erc20TokenAmount;
+        Fee[] fees;
+        IERC721Token erc721Token;
+        uint256 erc721TokenId;
+        Property[] erc721TokenProperties;
+    }
+
+    // All fields except `erc1155TokenAmount` align
+    // with those of NFTOrder
+    struct ERC1155Order {
+        TradeDirection direction;
+        address maker;
+        address taker;
+        uint256 expiry;
+        uint256 nonce;
+        IERC20TokenV06 erc20Token;
+        uint256 erc20TokenAmount;
+        Fee[] fees;
+        IERC1155Token erc1155Token;
+        uint256 erc1155TokenId;
+        Property[] erc1155TokenProperties;
+        // End of fields shared with NFTOrder
+        uint128 erc1155TokenAmount;
+    }
+
+    struct OrderInfo {
+        bytes32 orderHash;
+        OrderStatus status;
+        // `orderAmount` is 1 for all ERC721Orders, and
+        // `erc1155TokenAmount` for ERC1155Orders.
+        uint128 orderAmount;
+        // The remaining amount of the ERC721/ERC1155 asset
+        // that can be filled for the order.
+        uint128 remainingAmount;
+    }
+
+    // The type hash for ERC721 orders, which is:
+    // keccak256(abi.encodePacked(
+    //     "ERC721Order(",
+    //       "uint8 direction,",
+    //       "address maker,",
+    //       "address taker,",
+    //       "uint256 expiry,",
+    //       "uint256 nonce,",
+    //       "address erc20Token,",
+    //       "uint256 erc20TokenAmount,",
+    //       "Fee[] fees,",
+    //       "address erc721Token,",
+    //       "uint256 erc721TokenId,",
+    //       "Property[] erc721TokenProperties",
+    //     ")",
+    //     "Fee(",
+    //       "address recipient,",
+    //       "uint256 amount,",
+    //       "bytes feeData",
+    //     ")",
+    //     "Property(",
+    //       "address propertyValidator,",
+    //       "bytes propertyData",
+    //     ")"
+    // ))
+    uint256 private constant _ERC_721_ORDER_TYPEHASH =
+        0x2de32b2b090da7d8ab83ca4c85ba2eb6957bc7f6c50cb4ae1995e87560d808ed;
+
+    // The type hash for ERC1155 orders, which is:
+    // keccak256(abi.encodePacked(
+    //     "ERC1155Order(",
+    //       "uint8 direction,",
+    //       "address maker,",
+    //       "address taker,",
+    //       "uint256 expiry,",
+    //       "uint256 nonce,",
+    //       "address erc20Token,",
+    //       "uint256 erc20TokenAmount,",
+    //       "Fee[] fees,",
+    //       "address erc1155Token,",
+    //       "uint256 erc1155TokenId,",
+    //       "Property[] erc1155TokenProperties,",
+    //       "uint128 erc1155TokenAmount",
+    //     ")",
+    //     "Fee(",
+    //       "address recipient,",
+    //       "uint256 amount,",
+    //       "bytes feeData",
+    //     ")",
+    //     "Property(",
+    //       "address propertyValidator,",
+    //       "bytes propertyData",
+    //     ")"
+    // ))
+    uint256 private constant _ERC_1155_ORDER_TYPEHASH =
+        0x930490b1bcedd2e5139e22c761fafd52e533960197c2283f3922c7fd8c880be9;
+
+    // keccak256(abi.encodePacked(
+    //     "Fee(",
+    //       "address recipient,",
+    //       "uint256 amount,",
+    //       "bytes feeData",
+    //     ")"
+    // ))
+    uint256 private constant _FEE_TYPEHASH =
+        0xe68c29f1b4e8cce0bbcac76eb1334bdc1dc1f293a517c90e9e532340e1e94115;
+
+    // keccak256(abi.encodePacked(
+    //     "Property(",
+    //       "address propertyValidator,",
+    //       "bytes propertyData",
+    //     ")"
+    // ))
+    uint256 private constant _PROPERTY_TYPEHASH =
+        0x6292cf854241cb36887e639065eca63b3af9f7f70270cebeda4c29b6d3bc65e8;
+
+    // keccak256("");
+    bytes32 private constant _EMPTY_ARRAY_KECCAK256 =
+        0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;
+
+    // keccak256(abi.encodePacked(keccak256(abi.encode(
+    //     _PROPERTY_TYPEHASH,
+    //     address(0),
+    //     keccak256("")
+    // ))));
+    bytes32 private constant _NULL_PROPERTY_STRUCT_HASH =
+        0x720ee400a9024f6a49768142c339bf09d2dd9056ab52d20fbe7165faba6e142d;
+
+    uint256 private constant ADDRESS_MASK = (1 << 160) - 1;
+
+    // ERC721Order and NFTOrder fields are aligned, so
+    // we can safely cast an ERC721Order to an NFTOrder.
+    function asNFTOrder(ERC721Order memory erc721Order)
+        internal
+        pure
+        returns (NFTOrder memory nftOrder)
+    {
+        assembly {
+            nftOrder := erc721Order
+        }
+    }
+
+    // ERC1155Order and NFTOrder fields are aligned with
+    // the exception of the last field `erc1155TokenAmount`
+    // in ERC1155Order, so we can safely cast an ERC1155Order
+    // to an NFTOrder.
+    function asNFTOrder(ERC1155Order memory erc1155Order)
+        internal
+        pure
+        returns (NFTOrder memory nftOrder)
+    {
+        assembly {
+            nftOrder := erc1155Order
+        }
+    }
+
+    // ERC721Order and NFTOrder fields are aligned, so
+    // we can safely cast an MFTOrder to an ERC721Order.
+    function asERC721Order(NFTOrder memory nftOrder)
+        internal
+        pure
+        returns (ERC721Order memory erc721Order)
+    {
+        assembly {
+            erc721Order := nftOrder
+        }
+    }
+
+    // NOTE: This is only safe if `nftOrder` was previously
+    // cast from an `ERC1155Order` and the original
+    // `erc1155TokenAmount` memory word has not been corrupted!
+    function asERC1155Order(
+        NFTOrder memory nftOrder
+    )
+        internal
+        pure
+        returns (ERC1155Order memory erc1155Order)
+    {
+        assembly {
+            erc1155Order := nftOrder
+        }
+    }
+
+    /// @dev Get the struct hash of an ERC721 order.
+    /// @param order The ERC721 order.
+    /// @return structHash The struct hash of the order.
+    function getERC721OrderStructHash(ERC721Order memory order)
+        internal
+        pure
+        returns (bytes32 structHash)
+    {
+        bytes32 propertiesHash = _propertiesHash(order.erc721TokenProperties);
+        bytes32 feesHash = _feesHash(order.fees);
+
+        // Hash in place, equivalent to:
+        // return keccak256(abi.encode(
+        //     _ERC_721_ORDER_TYPEHASH,
+        //     order.direction,
+        //     order.maker,
+        //     order.taker,
+        //     order.expiry,
+        //     order.nonce,
+        //     order.erc20Token,
+        //     order.erc20TokenAmount,
+        //     feesHash,
+        //     order.erc721Token,
+        //     order.erc721TokenId,
+        //     propertiesHash
+        // ));
+        assembly {
+            if lt(order, 32) { invalid() } // Don't underflow memory.
+
+            let typeHashPos := sub(order, 32) // order - 32
+            let feesHashPos := add(order, 224) // order + (32 * 7)
+            let propertiesHashPos := add(order, 320) // order + (32 * 10)
+
+            let typeHashMemBefore := mload(typeHashPos)
+            let feeHashMemBefore := mload(feesHashPos)
+            let propertiesHashMemBefore := mload(propertiesHashPos)
+
+            mstore(typeHashPos, _ERC_721_ORDER_TYPEHASH)
+            mstore(feesHashPos, feesHash)
+            mstore(propertiesHashPos, propertiesHash)
+            structHash := keccak256(typeHashPos, 384 /* 32 * 12 */ )
+
+            mstore(typeHashPos, typeHashMemBefore)
+            mstore(feesHashPos, feeHashMemBefore)
+            mstore(propertiesHashPos, propertiesHashMemBefore)
+        }
+        return structHash;
+    }
+
+    /// @dev Get the struct hash of an ERC1155 order.
+    /// @param order The ERC1155 order.
+    /// @return structHash The struct hash of the order.
+    function getERC1155OrderStructHash(ERC1155Order memory order)
+        internal
+        pure
+        returns (bytes32 structHash)
+    {
+        bytes32 propertiesHash = _propertiesHash(order.erc1155TokenProperties);
+        bytes32 feesHash = _feesHash(order.fees);
+
+        // Hash in place, equivalent to:
+        // return keccak256(abi.encode(
+        //     _ERC_1155_ORDER_TYPEHASH,
+        //     order.direction,
+        //     order.maker,
+        //     order.taker,
+        //     order.expiry,
+        //     order.nonce,
+        //     order.erc20Token,
+        //     order.erc20TokenAmount,
+        //     feesHash,
+        //     order.erc1155Token,
+        //     order.erc1155TokenId,
+        //     propertiesHash,
+        //     order.erc1155TokenAmount
+        // ));
+        assembly {
+            if lt(order, 32) { invalid() } // Don't underflow memory.
+
+            let typeHashPos := sub(order, 32) // order - 32
+            let feesHashPos := add(order, 224) // order + (32 * 7)
+            let propertiesHashPos := add(order, 320) // order + (32 * 10)
+
+            let typeHashMemBefore := mload(typeHashPos)
+            let feesHashMemBefore := mload(feesHashPos)
+            let propertiesHashMemBefore := mload(propertiesHashPos)
+
+            mstore(typeHashPos, _ERC_1155_ORDER_TYPEHASH)
+            mstore(feesHashPos, feesHash)
+            mstore(propertiesHashPos, propertiesHash)
+            structHash := keccak256(typeHashPos, 416 /* 32 * 12 */ )
+
+            mstore(typeHashPos, typeHashMemBefore)
+            mstore(feesHashPos, feesHashMemBefore)
+            mstore(propertiesHashPos, propertiesHashMemBefore)
+        }
+        return structHash;
+    }
+
+    // Hashes the `properties` array as part of computing the
+    // EIP-712 hash of an `ERC721Order` or `ERC1155Order`.
+    function _propertiesHash(Property[] memory properties)
+        private
+        pure
+        returns (bytes32 propertiesHash)
+    {
+        uint256 numProperties = properties.length;
+        // We give `properties.length == 0` and `properties.length == 1`
+        // special treatment because we expect these to be the most common.
+        if (numProperties == 0) {
+            propertiesHash = _EMPTY_ARRAY_KECCAK256;
+        } else if (numProperties == 1) {
+            Property memory property = properties[0];
+            if (
+                address(property.propertyValidator) == address(0) &&
+                property.propertyData.length == 0
+            ) {
+                propertiesHash = _NULL_PROPERTY_STRUCT_HASH;
+            } else {
+                // propertiesHash = keccak256(abi.encodePacked(keccak256(abi.encode(
+                //     _PROPERTY_TYPEHASH,
+                //     properties[0].propertyValidator,
+                //     keccak256(properties[0].propertyData)
+                // ))));
+                bytes32 dataHash = keccak256(property.propertyData);
+                assembly {
+                    // Load free memory pointer
+                    let mem := mload(64)
+                    mstore(mem, _PROPERTY_TYPEHASH)
+                    // property.propertyValidator
+                    mstore(add(mem, 32), and(ADDRESS_MASK, mload(property)))
+                    // keccak256(property.propertyData)
+                    mstore(add(mem, 64), dataHash)
+                    mstore(mem, keccak256(mem, 96))
+                    propertiesHash := keccak256(mem, 32)
+                }
+            }
+        } else {
+            bytes32[] memory propertyStructHashArray = new bytes32[](numProperties);
+            for (uint256 i = 0; i < numProperties; i++) {
+                propertyStructHashArray[i] = keccak256(abi.encode(
+                    _PROPERTY_TYPEHASH,
+                    properties[i].propertyValidator,
+                    keccak256(properties[i].propertyData)
+                ));
+            }
+            assembly {
+                propertiesHash := keccak256(add(propertyStructHashArray, 32), mul(numProperties, 32))
+            }
+        }
+    }
+
+    // Hashes the `fees` array as part of computing the
+    // EIP-712 hash of an `ERC721Order` or `ERC1155Order`.
+    function _feesHash(Fee[] memory fees)
+        private
+        pure
+        returns (bytes32 feesHash)
+    {
+        uint256 numFees = fees.length;
+        // We give `fees.length == 0` and `fees.length == 1`
+        // special treatment because we expect these to be the most common.
+        if (numFees == 0) {
+            feesHash = _EMPTY_ARRAY_KECCAK256;
+        } else if (numFees == 1) {
+            // feesHash = keccak256(abi.encodePacked(keccak256(abi.encode(
+            //     _FEE_TYPEHASH,
+            //     fees[0].recipient,
+            //     fees[0].amount,
+            //     keccak256(fees[0].feeData)
+            // ))));
+            Fee memory fee = fees[0];
+            bytes32 dataHash = keccak256(fee.feeData);
+            assembly {
+                // Load free memory pointer
+                let mem := mload(64)
+                mstore(mem, _FEE_TYPEHASH)
+                // fee.recipient
+                mstore(add(mem, 32), and(ADDRESS_MASK, mload(fee)))
+                // fee.amount
+                mstore(add(mem, 64), mload(add(fee, 32)))
+                // keccak256(fee.feeData)
+                mstore(add(mem, 96), dataHash)
+                mstore(mem, keccak256(mem, 128))
+                feesHash := keccak256(mem, 32)
+            }
+        } else {
+            bytes32[] memory feeStructHashArray = new bytes32[](numFees);
+            for (uint256 i = 0; i < numFees; i++) {
+                feeStructHashArray[i] = keccak256(abi.encode(
+                    _FEE_TYPEHASH,
+                    fees[i].recipient,
+                    fees[i].amount,
+                    keccak256(fees[i].feeData)
+                ));
+            }
+            assembly {
+                feesHash := keccak256(add(feeStructHashArray, 32), mul(numFees, 32))
+            }
+        }
+    }
+}
--- a/contracts/zero-ex/contracts/src/features/libs/LibSignature.sol
+++ b/contracts/zero-ex/contracts/src/features/libs/LibSignature.sol
@@ -44,7 +44,8 @@ library LibSignature {
        ILLEGAL,
        INVALID,
        EIP712,
-        ETHSIGN
+        ETHSIGN,
+        PRESIGNED
    }

    /// @dev Encoded EC signature.
@@ -146,6 +147,15 @@ library LibSignature {
            ).rrevert();
        }

+        // If a feature supports pre-signing, it wouldn't use 
+        // `getSignerOfHash` on a pre-signed order.
+        if (signature.signatureType == SignatureType.PRESIGNED) {
+            LibSignatureRichErrors.SignatureValidationError(
+                LibSignatureRichErrors.SignatureValidationErrorCodes.UNSUPPORTED,
+                hash
+            ).rrevert();
+        }
+
        // Solidity should check that the signature type is within enum range for us
        // when abi-decoding.
    }
--- a/contracts/zero-ex/contracts/src/features/multiplex/MultiplexFeature.sol
+++ b/contracts/zero-ex/contracts/src/features/multiplex/MultiplexFeature.sol
@@ -622,15 +622,6 @@ contract MultiplexFeature is
            _executeBatchSell(batchSellParams).boughtAmount;
    }

-    // Transfers some amount of ETH to the given recipient and
-    // reverts if the transfer fails.
-    function _transferEth(address payable recipient, uint256 amount)
-        private
-    {
-        (bool success,) = recipient.call{value: amount}("");
-        require(success, "MultiplexFeature::_transferEth/TRANSFER_FAILED");
-    }
-
    // This function computes the "target" address of hop index `i` within
    // a multi-hop sell.
    // If `i == 0`, the target is the address which should hold the input
--- a/contracts/zero-ex/contracts/src/features/nft_orders/ERC1155OrdersFeature.sol
+++ b/contracts/zero-ex/contracts/src/features/nft_orders/ERC1155OrdersFeature.sol
@@ -0,0 +1,635 @@
+// SPDX-License-Identifier: Apache-2.0
+/*
+
+  Copyright 2021 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 ^0.6;
+pragma experimental ABIEncoderV2;
+
+import "@0x/contracts-erc20/contracts/src/v06/IEtherTokenV06.sol";
+import "@0x/contracts-utils/contracts/src/v06/LibSafeMathV06.sol";
+import "../../fixins/FixinERC1155Spender.sol";
+import "../../migrations/LibMigrate.sol";
+import "../../storage/LibERC1155OrdersStorage.sol";
+import "../interfaces/IFeature.sol";
+import "../interfaces/IERC1155OrdersFeature.sol";
+import "../libs/LibNFTOrder.sol";
+import "../libs/LibSignature.sol";
+import "./NFTOrders.sol";
+
+
+/// @dev Feature for interacting with ERC1155 orders.
+contract ERC1155OrdersFeature is
+    IFeature,
+    IERC1155OrdersFeature,
+    FixinERC1155Spender,
+    NFTOrders
+{
+    using LibSafeMathV06 for uint256;
+    using LibSafeMathV06 for uint128;
+    using LibNFTOrder for LibNFTOrder.ERC1155Order;
+    using LibNFTOrder for LibNFTOrder.NFTOrder;
+
+    /// @dev Name of this feature.
+    string public constant override FEATURE_NAME = "ERC1155Orders";
+    /// @dev Version of this feature.
+    uint256 public immutable override FEATURE_VERSION = _encodeVersion(1, 0, 0);
+
+    /// @dev The magic return value indicating the success of a `onERC1155Received`.
+    bytes4 private constant ERC1155_RECEIVED_MAGIC_BYTES = this.onERC1155Received.selector;
+
+
+    constructor(address zeroExAddress, IEtherTokenV06 weth)
+        public
+        NFTOrders(zeroExAddress, weth)
+    {}
+
+    /// @dev Initialize and register this feature.
+    ///      Should be delegatecalled by `Migrate.migrate()`.
+    /// @return success `LibMigrate.SUCCESS` on success.
+    function migrate()
+        external
+        returns (bytes4 success)
+    {
+        _registerFeatureFunction(this.sellERC1155.selector);
+        _registerFeatureFunction(this.buyERC1155.selector);
+        _registerFeatureFunction(this.cancelERC1155Order.selector);
+        _registerFeatureFunction(this.batchBuyERC1155s.selector);
+        _registerFeatureFunction(this.onERC1155Received.selector);
+        _registerFeatureFunction(this.preSignERC1155Order.selector);
+        _registerFeatureFunction(this.validateERC1155OrderSignature.selector);
+        _registerFeatureFunction(this.validateERC1155OrderProperties.selector);
+        _registerFeatureFunction(this.getERC1155OrderInfo.selector);
+        _registerFeatureFunction(this.getERC1155OrderHash.selector);
+        return LibMigrate.MIGRATE_SUCCESS;
+    }
+
+    /// @dev Sells an ERC1155 asset to fill the given order.
+    /// @param buyOrder The ERC1155 buy order.
+    /// @param signature The order signature from the maker.
+    /// @param erc1155TokenId The ID of the ERC1155 asset being
+    ///        sold. If the given order specifies properties,
+    ///        the asset must satisfy those properties. Otherwise,
+    ///        it must equal the tokenId in the order.
+    /// @param erc1155SellAmount The amount of the ERC1155 asset
+    ///        to sell.
+    /// @param unwrapNativeToken If this parameter is true and the
+    ///        ERC20 token of the order is e.g. WETH, unwraps the
+    ///        token before transferring it to the taker.
+    /// @param callbackData If this parameter is non-zero, invokes
+    ///        `zeroExERC1155OrderCallback` on `msg.sender` after
+    ///        the ERC20 tokens have been transferred to `msg.sender`
+    ///        but before transferring the ERC1155 asset to the buyer.
+    function sellERC1155(
+        LibNFTOrder.ERC1155Order memory buyOrder,
+        LibSignature.Signature memory signature,
+        uint256 erc1155TokenId,
+        uint128 erc1155SellAmount,
+        bool unwrapNativeToken,
+        bytes memory callbackData
+    )
+        public
+        override
+    {
+        _sellERC1155(
+            buyOrder,
+            signature,
+            SellParams(
+                erc1155SellAmount,
+                erc1155TokenId,
+                unwrapNativeToken,
+                msg.sender, // taker
+                msg.sender, // owner
+                callbackData
+            )
+        );
+    }
+
+    /// @dev Buys an ERC1155 asset by filling the given order.
+    /// @param sellOrder The ERC1155 sell order.
+    /// @param signature The order signature.
+    /// @param erc1155BuyAmount The amount of the ERC1155 asset
+    ///        to buy.
+    /// @param callbackData If this parameter is non-zero, invokes
+    ///        `zeroExERC1155OrderCallback` on `msg.sender` after
+    ///        the ERC1155 asset has been transferred to `msg.sender`
+    ///        but before transferring the ERC20 tokens to the seller.
+    ///        Native tokens acquired during the callback can be used
+    ///        to fill the order.
+    function buyERC1155(
+        LibNFTOrder.ERC1155Order memory sellOrder,
+        LibSignature.Signature memory signature,
+        uint128 erc1155BuyAmount,
+        bytes memory callbackData
+    )
+        public
+        override
+        payable
+    {
+        uint256 ethBalanceBefore = address(this).balance
+            .safeSub(msg.value);
+        _buyERC1155(
+            sellOrder,
+            signature,
+            BuyParams(
+                erc1155BuyAmount,
+                msg.value,
+                callbackData
+            )
+        );
+        uint256 ethBalanceAfter = address(this).balance;
+        // Cannot use pre-existing ETH balance
+        if (ethBalanceAfter < ethBalanceBefore) {
+            LibNFTOrdersRichErrors.OverspentEthError(
+                ethBalanceBefore - ethBalanceAfter + msg.value,
+                msg.value
+            ).rrevert();
+        }
+        // Refund
+        _transferEth(msg.sender, ethBalanceAfter - ethBalanceBefore);
+    }
+
+    /// @dev Cancel a single ERC1155 order by its nonce. The caller
+    ///      should be the maker of the order. Silently succeeds if
+    ///      an order with the same nonce has already been filled or
+    ///      cancelled.
+    /// @param orderNonce The order nonce.
+    function cancelERC1155Order(uint256 orderNonce)
+        public
+        override
+    {
+        // The bitvector is indexed by the lower 8 bits of the nonce.
+        uint256 flag = 1 << (orderNonce & 255);
+        // Update order cancellation bit vector to indicate that the order
+        // has been cancelled/filled by setting the designated bit to 1.
+        LibERC1155OrdersStorage.getStorage().orderCancellationByMaker
+            [msg.sender][uint248(orderNonce >> 8)] |= flag;
+
+        emit ERC1155OrderCancelled(msg.sender, orderNonce);
+    }
+
+    /// @dev Cancel multiple ERC1155 orders by their nonces. The caller
+    ///      should be the maker of the orders. Silently succeeds if
+    ///      an order with the same nonce has already been filled or
+    ///      cancelled.
+    /// @param orderNonces The order nonces.
+    function batchCancelERC1155Orders(uint256[] calldata orderNonces)
+        external
+        override
+    {
+        for (uint256 i = 0; i < orderNonces.length; i++) {
+            cancelERC1155Order(orderNonces[i]);
+        }
+    }
+
+    /// @dev Buys multiple ERC1155 assets by filling the
+    ///      given orders.
+    /// @param sellOrders The ERC1155 sell orders.
+    /// @param signatures The order signatures.
+    /// @param erc1155FillAmounts The amounts of the ERC1155 assets
+    ///        to buy for each order.
+    /// @param callbackData The data (if any) to pass to the taker
+    ///        callback for each order. Refer to the `callbackData`
+    ///        parameter to for `buyERC1155`.
+    /// @param revertIfIncomplete If true, reverts if this
+    ///        function fails to fill any individual order.
+    /// @return successes An array of booleans corresponding to whether
+    ///         each order in `orders` was successfully filled.
+    function batchBuyERC1155s(
+        LibNFTOrder.ERC1155Order[] memory sellOrders,
+        LibSignature.Signature[] memory signatures,
+        uint128[] calldata erc1155FillAmounts,
+        bytes[] memory callbackData,
+        bool revertIfIncomplete
+    )
+        public
+        override
+        payable
+        returns (bool[] memory successes)
+    {
+        require(
+            sellOrders.length == signatures.length &&
+            sellOrders.length == erc1155FillAmounts.length &&
+            sellOrders.length == callbackData.length,
+            "ERC1155OrdersFeature::batchBuyERC1155s/ARRAY_LENGTH_MISMATCH"
+        );
+        successes = new bool[](sellOrders.length);
+
+        uint256 ethBalanceBefore = address(this).balance
+            .safeSub(msg.value);
+        if (revertIfIncomplete) {
+            for (uint256 i = 0; i < sellOrders.length; i++) {
+                // Will revert if _buyERC1155 reverts.
+                _buyERC1155(
+                    sellOrders[i],
+                    signatures[i],
+                    BuyParams(
+                        erc1155FillAmounts[i],
+                        address(this).balance.safeSub(ethBalanceBefore), // Remaining ETH available
+                        callbackData[i]
+                    )
+                );
+                successes[i] = true;
+            }
+        } else {
+            for (uint256 i = 0; i < sellOrders.length; i++) {
+                // Delegatecall `_buyERC1155` to catch swallow reverts while
+                // preserving execution context.
+                // Note that `_buyERC1155` is a public function but should _not_
+                // be registered in the Exchange Proxy.
+                (successes[i], ) = _implementation.delegatecall(
+                    abi.encodeWithSelector(
+                        this._buyERC1155.selector,
+                        sellOrders[i],
+                        signatures[i],
+                        BuyParams(
+                            erc1155FillAmounts[i],
+                            address(this).balance.safeSub(ethBalanceBefore), // Remaining ETH available
+                            callbackData[i]
+                        )
+                    )
+                );
+            }
+        }
+
+        // Cannot use pre-existing ETH balance
+        uint256 ethBalanceAfter = address(this).balance;
+        if (ethBalanceAfter < ethBalanceBefore) {
+            LibNFTOrdersRichErrors.OverspentEthError(
+                msg.value + (ethBalanceBefore - ethBalanceAfter),
+                msg.value
+            ).rrevert();
+        }
+
+        // Refund
+        _transferEth(msg.sender, ethBalanceAfter - ethBalanceBefore);
+    }
+
+    /// @dev Callback for the ERC1155 `safeTransferFrom` function.
+    ///      This callback can be used to sell an ERC1155 asset if
+    ///      a valid ERC1155 order, signature and `unwrapNativeToken`
+    ///      are encoded in `data`. This allows takers to sell their
+    ///      ERC1155 asset without first calling `setApprovalForAll`.
+    /// @param operator The address which called `safeTransferFrom`.
+    /// @param tokenId The ID of the asset being transferred.
+    /// @param value The amount being transferred.
+    /// @param data Additional data with no specified format. If a
+    ///        valid ERC1155 order, signature and `unwrapNativeToken`
+    ///        are encoded in `data`, this function will try to fill
+    ///        the order using the received asset.
+    /// @return success The selector of this function (0xf23a6e61),
+    ///         indicating that the callback succeeded.
+    function onERC1155Received(
+        address operator,
+        address /* from */,
+        uint256 tokenId,
+        uint256 value,
+        bytes calldata data
+    )
+        external
+        override
+        returns (bytes4 success)
+    {
+        // Decode the order, signature, and `unwrapNativeToken` from
+        // `data`. If `data` does not encode such parameters, this
+        // will throw.
+        (
+            LibNFTOrder.ERC1155Order memory buyOrder,
+            LibSignature.Signature memory signature,
+            bool unwrapNativeToken
+        ) = abi.decode(
+            data,
+            (LibNFTOrder.ERC1155Order, LibSignature.Signature, bool)
+        );
+
+        // `onERC1155Received` is called by the ERC1155 token contract.
+        // Check that it matches the ERC1155 token in the order.
+        if (msg.sender != address(buyOrder.erc1155Token)) {
+            LibNFTOrdersRichErrors.ERC1155TokenMismatchError(
+                msg.sender,
+                address(buyOrder.erc1155Token)
+            ).rrevert();
+        }
+
+        _sellERC1155(
+            buyOrder,
+            signature,
+            SellParams(
+                value.safeDowncastToUint128(),
+                tokenId,
+                unwrapNativeToken,
+                operator,       // taker
+                address(this),  // owner (we hold the NFT currently)
+                new bytes(0)    // No taker callback
+            )
+        );
+
+        return ERC1155_RECEIVED_MAGIC_BYTES;
+    }
+
+    /// @dev Approves an ERC1155 order on-chain. After pre-signing
+    ///      the order, the `PRESIGNED` signature type will become
+    ///      valid for that order and signer.
+    /// @param order An ERC1155 order.
+    function preSignERC1155Order(LibNFTOrder.ERC1155Order memory order)
+        public
+        override
+    {
+        require(
+            order.maker == msg.sender,
+            "ERC1155OrdersFeature::preSignERC1155Order/MAKER_MISMATCH"
+        );
+        bytes32 orderHash = getERC1155OrderHash(order);
+
+        LibERC1155OrdersStorage.Storage storage stor =
+            LibERC1155OrdersStorage.getStorage();
+        // Set `preSigned` to true on the order state variable
+        // to indicate that the order has been pre-signed.
+        stor.orderState[orderHash].preSigned = true;
+
+        emit ERC1155OrderPreSigned(
+            order.direction,
+            order.maker,
+            order.taker,
+            order.expiry,
+            order.nonce,
+            order.erc20Token,
+            order.erc20TokenAmount,
+            order.fees,
+            order.erc1155Token,
+            order.erc1155TokenId,
+            order.erc1155TokenProperties,
+            order.erc1155TokenAmount
+        );
+    }
+
+    // Core settlement logic for selling an ERC1155 asset.
+    // Used by `sellERC1155` and `onERC1155Received`.
+    function _sellERC1155(
+        LibNFTOrder.ERC1155Order memory buyOrder,
+        LibSignature.Signature memory signature,
+        SellParams memory params
+    )
+        private
+    {
+        uint256 erc20FillAmount = _sellNFT(
+            buyOrder.asNFTOrder(),
+            signature,
+            params
+        );
+
+        emit ERC1155OrderFilled(
+            buyOrder.direction,
+            buyOrder.maker,
+            params.taker,
+            buyOrder.nonce,
+            buyOrder.erc20Token,
+            erc20FillAmount,
+            buyOrder.erc1155Token,
+            params.tokenId,
+            params.sellAmount,
+            address(0)
+        );
+    }
+
+    // Core settlement logic for buying an ERC1155 asset.
+    // Used by `buyERC1155` and `batchBuyERC1155s`.
+    function _buyERC1155(
+        LibNFTOrder.ERC1155Order memory sellOrder,
+        LibSignature.Signature memory signature,
+        BuyParams memory params
+    )
+        public
+        payable
+    {
+        uint256 erc20FillAmount = _buyNFT(
+            sellOrder.asNFTOrder(),
+            signature,
+            params
+        );
+
+        emit ERC1155OrderFilled(
+            sellOrder.direction,
+            sellOrder.maker,
+            msg.sender,
+            sellOrder.nonce,
+            sellOrder.erc20Token,
+            erc20FillAmount,
+            sellOrder.erc1155Token,
+            sellOrder.erc1155TokenId,
+            params.buyAmount,
+            address(0)
+        );
+    }
+
+    /// @dev Checks whether the given signature is valid for the
+    ///      the given ERC1155 order. Reverts if not.
+    /// @param order The ERC1155 order.
+    /// @param signature The signature to validate.
+    function validateERC1155OrderSignature(
+        LibNFTOrder.ERC1155Order memory order,
+        LibSignature.Signature memory signature
+    )
+        public
+        override
+        view
+    {
+        bytes32 orderHash = getERC1155OrderHash(order);
+        _validateOrderSignature(orderHash, signature, order.maker);
+    }
+
+    /// @dev Validates that the given signature is valid for the
+    ///      given maker and order hash. Reverts if the signature
+    ///      is not valid.
+    /// @param orderHash The hash of the order that was signed.
+    /// @param signature The signature to check.
+    /// @param maker The maker of the order.
+    function _validateOrderSignature(
+        bytes32 orderHash,
+        LibSignature.Signature memory signature,
+        address maker
+    )
+        internal
+        override
+        view
+    {
+        if (signature.signatureType == LibSignature.SignatureType.PRESIGNED) {
+            // Check if order hash has been pre-signed by the maker.
+            bool isPreSigned = LibERC1155OrdersStorage.getStorage()
+                .orderState[orderHash].preSigned;
+            if (!isPreSigned) {
+                LibNFTOrdersRichErrors.InvalidSignerError(maker, address(0)).rrevert();
+            }
+        } else {
+            address signer = LibSignature.getSignerOfHash(orderHash, signature);
+            if (signer != maker) {
+                LibNFTOrdersRichErrors.InvalidSignerError(maker, signer).rrevert();
+            }
+        }
+    }
+
+    /// @dev Transfers an NFT asset.
+    /// @param token The address of the NFT contract.
+    /// @param from The address currently holding the asset.
+    /// @param to The address to transfer the asset to.
+    /// @param tokenId The ID of the asset to transfer.
+    /// @param amount The amount of the asset to transfer. Always
+    ///        1 for ERC721 assets.
+    function _transferNFTAssetFrom(
+        address token,
+        address from,
+        address to,
+        uint256 tokenId,
+        uint256 amount
+    )
+        internal
+        override
+    {
+        _transferERC1155AssetFrom(IERC1155Token(token), from, to, tokenId, amount);
+    }
+
+    /// @dev Updates storage to indicate that the given order
+    ///      has been filled by the given amount.
+    /// @param orderHash The hash of `order`.
+    /// @param fillAmount The amount (denominated in the NFT asset)
+    ///        that the order has been filled by.
+    function _updateOrderState(
+        LibNFTOrder.NFTOrder memory /* order */,
+        bytes32 orderHash,
+        uint128 fillAmount
+    )
+        internal
+        override
+    {
+        LibERC1155OrdersStorage.Storage storage stor = LibERC1155OrdersStorage.getStorage();
+        uint128 filledAmount = stor.orderState[orderHash].filledAmount;
+        // Filled amount should never overflow 128 bits
+        assert(filledAmount + fillAmount > filledAmount);
+        stor.orderState[orderHash].filledAmount = filledAmount + fillAmount;
+    }
+
+    /// @dev If the given order is buying an ERC1155 asset, checks
+    ///      whether or not the given token ID satisfies the required
+    ///      properties specified in the order. If the order does not
+    ///      specify any properties, this function instead checks
+    ///      whether the given token ID matches the ID in the order.
+    ///      Reverts if any checks fail, or if the order is selling
+    ///      an ERC1155 asset.
+    /// @param order The ERC1155 order.
+    /// @param erc1155TokenId The ID of the ERC1155 asset.
+    function validateERC1155OrderProperties(
+        LibNFTOrder.ERC1155Order memory order,
+        uint256 erc1155TokenId
+    )
+        public
+        override
+        view
+    {
+        _validateOrderProperties(
+            order.asNFTOrder(),
+            erc1155TokenId
+        );
+    }
+
+    /// @dev Get the order info for an ERC1155 order.
+    /// @param order The ERC1155 order.
+    /// @return orderInfo Info about the order.
+    function getERC1155OrderInfo(LibNFTOrder.ERC1155Order memory order)
+        public
+        override
+        view
+        returns (LibNFTOrder.OrderInfo memory orderInfo)
+    {
+        orderInfo.orderAmount = order.erc1155TokenAmount;
+        orderInfo.orderHash = getERC1155OrderHash(order);
+
+        // Only buy orders with `erc1155TokenId` == 0 can be property
+        // orders.
+        if (order.erc1155TokenProperties.length > 0 &&
+                (order.direction != LibNFTOrder.TradeDirection.BUY_NFT ||
+                 order.erc1155TokenId != 0))
+        {
+            orderInfo.status = LibNFTOrder.OrderStatus.INVALID;
+            return orderInfo;
+        }
+
+        // Buy orders cannot use ETH as the ERC20 token, since ETH cannot be
+        // transferred from the buyer by a contract.
+        if (order.direction == LibNFTOrder.TradeDirection.BUY_NFT &&
+            address(order.erc20Token) == NATIVE_TOKEN_ADDRESS)
+        {
+            orderInfo.status = LibNFTOrder.OrderStatus.INVALID;
+            return orderInfo;
+        }
+
+        // Check for expiry.
+        if (order.expiry <= block.timestamp) {
+            orderInfo.status = LibNFTOrder.OrderStatus.EXPIRED;
+            return orderInfo;
+        }
+
+        {
+            LibERC1155OrdersStorage.Storage storage stor =
+                LibERC1155OrdersStorage.getStorage();
+
+            LibERC1155OrdersStorage.OrderState storage orderState =
+                stor.orderState[orderInfo.orderHash];
+            orderInfo.remainingAmount = order.erc1155TokenAmount
+                .safeSub128(orderState.filledAmount);
+
+            // `orderCancellationByMaker` is indexed by maker and nonce.
+            uint256 orderCancellationBitVector =
+                stor.orderCancellationByMaker[order.maker][uint248(order.nonce >> 8)];
+            // The bitvector is indexed by the lower 8 bits of the nonce.
+            uint256 flag = 1 << (order.nonce & 255);
+
+            if (orderInfo.remainingAmount == 0 ||
+                orderCancellationBitVector & flag != 0)
+            {
+                orderInfo.status = LibNFTOrder.OrderStatus.UNFILLABLE;
+                return orderInfo;
+            }
+        }
+
+        // Otherwise, the order is fillable.
+        orderInfo.status = LibNFTOrder.OrderStatus.FILLABLE;
+    }
+
+    /// @dev Get the order info for an NFT order.
+    /// @param order The NFT order.
+    /// @return orderInfo Info about the order.
+    function _getOrderInfo(LibNFTOrder.NFTOrder memory order)
+        internal
+        override
+        view
+        returns (LibNFTOrder.OrderInfo memory orderInfo)
+    {
+        return getERC1155OrderInfo(order.asERC1155Order());
+    }
+
+    /// @dev Get the EIP-712 hash of an ERC1155 order.
+    /// @param order The ERC1155 order.
+    /// @return orderHash The order hash.
+    function getERC1155OrderHash(LibNFTOrder.ERC1155Order memory order)
+        public
+        override
+        view
+        returns (bytes32 orderHash)
+    {
+        return _getEIP712Hash(LibNFTOrder.getERC1155OrderStructHash(order));
+    }
+}
--- a/contracts/zero-ex/contracts/src/features/nft_orders/ERC721OrdersFeature.sol
+++ b/contracts/zero-ex/contracts/src/features/nft_orders/ERC721OrdersFeature.sol
@@ -0,0 +1,931 @@
+// SPDX-License-Identifier: Apache-2.0
+/*
+
+  Copyright 2021 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 ^0.6;
+pragma experimental ABIEncoderV2;
+
+import "@0x/contracts-erc20/contracts/src/v06/IEtherTokenV06.sol";
+import "@0x/contracts-utils/contracts/src/v06/LibSafeMathV06.sol";
+import "../../fixins/FixinERC721Spender.sol";
+import "../../migrations/LibMigrate.sol";
+import "../../storage/LibERC721OrdersStorage.sol";
+import "../interfaces/IFeature.sol";
+import "../interfaces/IERC721OrdersFeature.sol";
+import "../libs/LibNFTOrder.sol";
+import "../libs/LibSignature.sol";
+import "./NFTOrders.sol";
+
+
+/// @dev Feature for interacting with ERC721 orders.
+contract ERC721OrdersFeature is
+    IFeature,
+    IERC721OrdersFeature,
+    FixinERC721Spender,
+    NFTOrders
+{
+    using LibSafeMathV06 for uint256;
+    using LibNFTOrder for LibNFTOrder.ERC721Order;
+    using LibNFTOrder for LibNFTOrder.NFTOrder;
+
+    /// @dev Name of this feature.
+    string public constant override FEATURE_NAME = "ERC721Orders";
+    /// @dev Version of this feature.
+    uint256 public immutable override FEATURE_VERSION = _encodeVersion(1, 0, 0);
+
+    /// @dev The magic return value indicating the success of a `onERC721Received`.
+    bytes4 private constant ERC721_RECEIVED_MAGIC_BYTES = this.onERC721Received.selector;
+
+
+    constructor(address zeroExAddress, IEtherTokenV06 weth)
+        public
+        NFTOrders(zeroExAddress, weth)
+    {}
+
+    /// @dev Initialize and register this feature.
+    ///      Should be delegatecalled by `Migrate.migrate()`.
+    /// @return success `LibMigrate.SUCCESS` on success.
+    function migrate()
+        external
+        returns (bytes4 success)
+    {
+        _registerFeatureFunction(this.sellERC721.selector);
+        _registerFeatureFunction(this.buyERC721.selector);
+        _registerFeatureFunction(this.cancelERC721Order.selector);
+        _registerFeatureFunction(this.batchBuyERC721s.selector);
+        _registerFeatureFunction(this.matchERC721Orders.selector);
+        _registerFeatureFunction(this.batchMatchERC721Orders.selector);
+        _registerFeatureFunction(this.onERC721Received.selector);
+        _registerFeatureFunction(this.preSignERC721Order.selector);
+        _registerFeatureFunction(this.validateERC721OrderSignature.selector);
+        _registerFeatureFunction(this.validateERC721OrderProperties.selector);
+        _registerFeatureFunction(this.getERC721OrderStatus.selector);
+        _registerFeatureFunction(this.getERC721OrderHash.selector);
+        _registerFeatureFunction(this.getERC721OrderStatusBitVector.selector);
+        return LibMigrate.MIGRATE_SUCCESS;
+    }
+
+    /// @dev Sells an ERC721 asset to fill the given order.
+    /// @param buyOrder The ERC721 buy order.
+    /// @param signature The order signature from the maker.
+    /// @param erc721TokenId The ID of the ERC721 asset being
+    ///        sold. If the given order specifies properties,
+    ///        the asset must satisfy those properties. Otherwise,
+    ///        it must equal the tokenId in the order.
+    /// @param unwrapNativeToken If this parameter is true and the
+    ///        ERC20 token of the order is e.g. WETH, unwraps the
+    ///        token before transferring it to the taker.
+    /// @param callbackData If this parameter is non-zero, invokes
+    ///        `zeroExERC721OrderCallback` on `msg.sender` after
+    ///        the ERC20 tokens have been transferred to `msg.sender`
+    ///        but before transferring the ERC721 asset to the buyer.
+    function sellERC721(
+        LibNFTOrder.ERC721Order memory buyOrder,
+        LibSignature.Signature memory signature,
+        uint256 erc721TokenId,
+        bool unwrapNativeToken,
+        bytes memory callbackData
+    )
+        public
+        override
+    {
+        _sellERC721(
+            buyOrder,
+            signature,
+            erc721TokenId,
+            unwrapNativeToken,
+            msg.sender, // taker
+            msg.sender, // owner
+            callbackData
+        );
+    }
+
+    /// @dev Buys an ERC721 asset by filling the given order.
+    /// @param sellOrder The ERC721 sell order.
+    /// @param signature The order signature.
+    /// @param callbackData If this parameter is non-zero, invokes
+    ///        `zeroExERC721OrderCallback` on `msg.sender` after
+    ///        the ERC721 asset has been transferred to `msg.sender`
+    ///        but before transferring the ERC20 tokens to the seller.
+    ///        Native tokens acquired during the callback can be used
+    ///        to fill the order.
+    function buyERC721(
+        LibNFTOrder.ERC721Order memory sellOrder,
+        LibSignature.Signature memory signature,
+        bytes memory callbackData
+    )
+        public
+        override
+        payable
+    {
+        uint256 ethBalanceBefore = address(this).balance
+            .safeSub(msg.value);
+        _buyERC721(
+            sellOrder,
+            signature,
+            msg.value,
+            callbackData
+        );
+        uint256 ethBalanceAfter = address(this).balance;
+        // Cannot use pre-existing ETH balance
+        if (ethBalanceAfter < ethBalanceBefore) {
+            LibNFTOrdersRichErrors.OverspentEthError(
+                msg.value + (ethBalanceBefore - ethBalanceAfter),
+                msg.value
+            ).rrevert();
+        }
+        // Refund
+        _transferEth(msg.sender, ethBalanceAfter - ethBalanceBefore);
+    }
+
+    /// @dev Cancel a single ERC721 order by its nonce. The caller
+    ///      should be the maker of the order. Silently succeeds if
+    ///      an order with the same nonce has already been filled or
+    ///      cancelled.
+    /// @param orderNonce The order nonce.
+    function cancelERC721Order(uint256 orderNonce)
+        public
+        override
+    {
+        // Mark order as cancelled
+        _setOrderStatusBit(msg.sender, orderNonce);
+        emit ERC721OrderCancelled(msg.sender, orderNonce);
+    }
+
+    /// @dev Cancel multiple ERC721 orders by their nonces. The caller
+    ///      should be the maker of the orders. Silently succeeds if
+    ///      an order with the same nonce has already been filled or
+    ///      cancelled.
+    /// @param orderNonces The order nonces.
+    function batchCancelERC721Orders(uint256[] calldata orderNonces)
+        external
+        override
+    {
+        for (uint256 i = 0; i < orderNonces.length; i++) {
+            cancelERC721Order(orderNonces[i]);
+        }
+    }
+
+    /// @dev Buys multiple ERC721 assets by filling the
+    ///      given orders.
+    /// @param sellOrders The ERC721 sell orders.
+    /// @param signatures The order signatures.
+    /// @param revertIfIncomplete If true, reverts if this
+    ///        function fails to fill any individual order.
+    /// @param callbackData The data (if any) to pass to the taker
+    ///        callback for each order. Refer to the `callbackData`
+    ///        parameter to for `buyERC721`.
+    /// @return successes An array of booleans corresponding to whether
+    ///         each order in `orders` was successfully filled.
+    function batchBuyERC721s(
+        LibNFTOrder.ERC721Order[] memory sellOrders,
+        LibSignature.Signature[] memory signatures,
+        bytes[] memory callbackData,
+        bool revertIfIncomplete
+    )
+        public
+        override
+        payable
+        returns (bool[] memory successes)
+    {
+        require(
+            sellOrders.length == signatures.length &&
+            sellOrders.length == callbackData.length,
+            "ERC721OrdersFeature::batchBuyERC721s/ARRAY_LENGTH_MISMATCH"
+        );
+        successes = new bool[](sellOrders.length);
+
+        uint256 ethBalanceBefore = address(this).balance
+            .safeSub(msg.value);
+        if (revertIfIncomplete) {
+            for (uint256 i = 0; i < sellOrders.length; i++) {
+                // Will revert if _buyERC721 reverts.
+                _buyERC721(
+                    sellOrders[i],
+                    signatures[i],
+                    address(this).balance.safeSub(ethBalanceBefore),
+                    callbackData[i]
+                );
+                successes[i] = true;
+            }
+        } else {
+            for (uint256 i = 0; i < sellOrders.length; i++) {
+                // Delegatecall `_buyERC721` to swallow reverts while
+                // preserving execution context.
+                // Note that `_buyERC721` is a public function but should _not_
+                // be registered in the Exchange Proxy.
+                (successes[i], ) = _implementation.delegatecall(
+                    abi.encodeWithSelector(
+                        this._buyERC721.selector,
+                        sellOrders[i],
+                        signatures[i],
+                        address(this).balance.safeSub(ethBalanceBefore), // Remaining ETH available
+                        callbackData[i]
+                    )
+                );
+            }
+        }
+
+        // Cannot use pre-existing ETH balance
+        uint256 ethBalanceAfter = address(this).balance;
+        if (ethBalanceAfter < ethBalanceBefore) {
+            LibNFTOrdersRichErrors.OverspentEthError(
+                msg.value + (ethBalanceBefore - ethBalanceAfter),
+                msg.value
+            ).rrevert();
+        }
+
+        // Refund
+        _transferEth(msg.sender, ethBalanceAfter - ethBalanceBefore);
+    }
+
+    /// @dev Matches a pair of complementary orders that have
+    ///      a non-negative spread. Each order is filled at
+    ///      their respective price, and the matcher receives
+    ///      a profit denominated in the ERC20 token.
+    /// @param sellOrder Order selling an ERC721 asset.
+    /// @param buyOrder Order buying an ERC721 asset.
+    /// @param sellOrderSignature Signature for the sell order.
+    /// @param buyOrderSignature Signature for the buy order.
+    /// @return profit The amount of profit earned by the caller
+    ///         of this function (denominated in the ERC20 token
+    ///         of the matched orders).
+    function matchERC721Orders(
+        LibNFTOrder.ERC721Order memory sellOrder,
+        LibNFTOrder.ERC721Order memory buyOrder,
+        LibSignature.Signature memory sellOrderSignature,
+        LibSignature.Signature memory buyOrderSignature
+    )
+        public
+        override
+        returns (uint256 profit)
+    {
+        // The ERC721 tokens must match
+        if (sellOrder.erc721Token != buyOrder.erc721Token) {
+            LibNFTOrdersRichErrors.ERC721TokenMismatchError(
+                address(sellOrder.erc721Token),
+                address(buyOrder.erc721Token)
+            ).rrevert();
+        }
+
+        LibNFTOrder.NFTOrder memory sellNFTOrder = sellOrder.asNFTOrder();
+        LibNFTOrder.NFTOrder memory buyNFTOrder = buyOrder.asNFTOrder();
+
+        {
+            LibNFTOrder.OrderInfo memory sellOrderInfo = _getOrderInfo(sellNFTOrder);
+            LibNFTOrder.OrderInfo memory buyOrderInfo = _getOrderInfo(buyNFTOrder);
+
+            _validateSellOrder(
+                sellNFTOrder,
+                sellOrderSignature,
+                sellOrderInfo,
+                buyOrder.maker
+            );
+            _validateBuyOrder(
+                buyNFTOrder,
+                buyOrderSignature,
+                buyOrderInfo,
+                sellOrder.maker,
+                sellOrder.erc721TokenId
+            );
+
+            // Mark both orders as filled.
+            _updateOrderState(sellNFTOrder, sellOrderInfo.orderHash, 1);
+            _updateOrderState(buyNFTOrder, buyOrderInfo.orderHash, 1);
+        }
+
+        // The buyer must be willing to pay at least the amount that the
+        // seller is asking.
+        if (buyOrder.erc20TokenAmount < sellOrder.erc20TokenAmount) {
+            LibNFTOrdersRichErrors.NegativeSpreadError(
+                sellOrder.erc20TokenAmount,
+                buyOrder.erc20TokenAmount
+            ).rrevert();
+        }
+
+        // The difference in ERC20 token amounts is the spread.
+        uint256 spread = buyOrder.erc20TokenAmount - sellOrder.erc20TokenAmount;
+
+        // Transfer the ERC721 asset from seller to buyer.
+        _transferERC721AssetFrom(
+            sellOrder.erc721Token,
+            sellOrder.maker,
+            buyOrder.maker,
+            sellOrder.erc721TokenId
+        );
+
+        // Handle the ERC20 side of the order:
+        if (
+            address(sellOrder.erc20Token) == NATIVE_TOKEN_ADDRESS &&
+            buyOrder.erc20Token == WETH
+        ) {
+            // The sell order specifies ETH, while the buy order specifies WETH.
+            // The orders are still compatible with one another, but we'll have
+            // to unwrap the WETH on behalf of the buyer.
+
+            // Step 1: Transfer WETH from the buyer to the EP.
+            //         Note that we transfer `buyOrder.erc20TokenAmount`, which
+            //         is the amount the buyer signaled they are willing to pay
+            //         for the ERC721 asset, which may be more than the seller's
+            //         ask.
+            _transferERC20TokensFrom(
+                WETH,
+                buyOrder.maker,
+                address(this),
+                buyOrder.erc20TokenAmount
+            );
+            // Step 2: Unwrap the WETH into ETH. We unwrap the entire
+            //         `buyOrder.erc20TokenAmount`.
+            //         The ETH will be used for three purposes:
+            //         - To pay the seller
+            //         - To pay fees for the sell order
+            //         - Any remaining ETH will be sent to
+            //           `msg.sender` as profit.
+            WETH.withdraw(buyOrder.erc20TokenAmount);
+
+            // Step 3: Pay the seller (in ETH).
+            _transferEth(payable(sellOrder.maker), sellOrder.erc20TokenAmount);
+
+            // Step 4: Pay fees for the buy order. Note that these are paid
+            //         in _WETH_ by the _buyer_. By signing the buy order, the
+            //         buyer signals that they are willing to spend a total
+            //         of `erc20TokenAmount` _plus_ fees, all denominated in
+            //         the `erc20Token`, which in this case is WETH.
+            _payFees(
+                buyNFTOrder,
+                buyOrder.maker, // payer
+                1,              // fillAmount
+                1,              // orderAmount
+                false           // useNativeToken
+            );
+
+            // Step 5: Pay fees for the sell order. The `erc20Token` of the
+            //         sell order is ETH, so the fees are paid out in ETH.
+            //         There should be `spread` wei of ETH remaining in the
+            //         EP at this point, which we will use ETH to pay the
+            //         sell order fees.
+            uint256 sellOrderFees = _payFees(
+                sellNFTOrder,
+                address(this), // payer
+                1,             // fillAmount
+                1,             // orderAmount
+                true           // useNativeToken
+            );
+
+            // Step 6: The spread must be enough to cover the sell order fees.
+            //         If not, either `_payFees` will have reverted, or we
+            //         have spent ETH that was in the EP before this
+            //         `matchERC721Orders` call, which we disallow.
+            if (spread < sellOrderFees) {
+                LibNFTOrdersRichErrors.SellOrderFeesExceedSpreadError(
+                    sellOrderFees,
+                    spread
+                ).rrevert();
+            }
+            // Step 7: The spread less the sell order fees is the amount of ETH
+            //         remaining in the EP that can be sent to `msg.sender` as
+            //         the profit from matching these two orders.
+            profit = spread - sellOrderFees;
+            if (profit > 0) {
+                _transferEth(msg.sender, profit);
+            }
+        } else {
+            // ERC20 tokens must match
+            if (sellOrder.erc20Token != buyOrder.erc20Token) {
+                LibNFTOrdersRichErrors.ERC20TokenMismatchError(
+                    address(sellOrder.erc20Token),
+                    address(buyOrder.erc20Token)
+                ).rrevert();
+            }
+
+            // Step 1: Transfer the ERC20 token from the buyer to the seller.
+            //         Note that we transfer `sellOrder.erc20TokenAmount`, which
+            //         is at most `buyOrder.erc20TokenAmount`.
+            _transferERC20TokensFrom(
+                buyOrder.erc20Token,
+                buyOrder.maker,
+                sellOrder.maker,
+                sellOrder.erc20TokenAmount
+            );
+
+            // Step 2: Pay fees for the buy order. Note that these are paid
+            //         by the buyer. By signing the buy order, the buyer signals
+            //         that they are willing to spend a total of
+            //         `buyOrder.erc20TokenAmount` _plus_ `buyOrder.fees`.
+            _payFees(
+                buyNFTOrder,
+                buyOrder.maker, // payer
+                1,              // fillAmount
+                1,              // orderAmount
+                false           // useNativeToken
+            );
+
+            // Step 3: Pay fees for the sell order. These are paid by the buyer
+            //         as well. After paying these fees, we may have taken more
+            //         from the buyer than they agreed to in the buy order. If
+            //         so, we revert in the following step.
+            uint256 sellOrderFees = _payFees(
+                sellNFTOrder,
+                buyOrder.maker, // payer
+                1,              // fillAmount
+                1,              // orderAmount
+                false           // useNativeToken
+            );
+
+            // Step 4: The spread must be enough to cover the sell order fees.
+            //         If not, `_payFees` will have taken more tokens from the
+            //         buyer than they had agreed to in the buy order, in which
+            //         case we revert here.
+            if (spread < sellOrderFees) {
+                LibNFTOrdersRichErrors.SellOrderFeesExceedSpreadError(
+                    sellOrderFees,
+                    spread
+                ).rrevert();
+            }
+
+            // Step 5: We calculate the profit as:
+            //         profit = buyOrder.erc20TokenAmount - sellOrder.erc20TokenAmount - sellOrderFees
+            //                = spread - sellOrderFees
+            //         I.e. the buyer would've been willing to pay up to `profit`
+            //         more to buy the asset, so instead that amount is sent to
+            //         `msg.sender` as the profit from matching these two orders.
+            profit = spread - sellOrderFees;
+            if (profit > 0) {
+                _transferERC20TokensFrom(
+                    buyOrder.erc20Token,
+                    buyOrder.maker,
+                    msg.sender,
+                    profit
+                );
+            }
+        }
+
+        emit ERC721OrderFilled(
+            sellOrder.direction,
+            sellOrder.maker,
+            buyOrder.maker, // taker
+            sellOrder.nonce,
+            sellOrder.erc20Token,
+            sellOrder.erc20TokenAmount,
+            sellOrder.erc721Token,
+            sellOrder.erc721TokenId,
+            msg.sender
+        );
+
+        emit ERC721OrderFilled(
+            buyOrder.direction,
+            buyOrder.maker,
+            sellOrder.maker, // taker
+            buyOrder.nonce,
+            buyOrder.erc20Token,
+            buyOrder.erc20TokenAmount,
+            buyOrder.erc721Token,
+            sellOrder.erc721TokenId,
+            msg.sender
+        );
+    }
+
+    /// @dev Matches pairs of complementary orders that have
+    ///      non-negative spreads. Each order is filled at
+    ///      their respective price, and the matcher receives
+    ///      a profit denominated in the ERC20 token.
+    /// @param sellOrders Orders selling ERC721 assets.
+    /// @param buyOrders Orders buying ERC721 assets.
+    /// @param sellOrderSignatures Signatures for the sell orders.
+    /// @param buyOrderSignatures Signatures for the buy orders.
+    /// @return profits The amount of profit earned by the caller
+    ///         of this function for each pair of matched orders
+    ///         (denominated in the ERC20 token of the order pair).
+    /// @return successes An array of booleans corresponding to
+    ///         whether each pair of orders was successfully matched.
+    function batchMatchERC721Orders(
+        LibNFTOrder.ERC721Order[] memory sellOrders,
+        LibNFTOrder.ERC721Order[] memory buyOrders,
+        LibSignature.Signature[] memory sellOrderSignatures,
+        LibSignature.Signature[] memory buyOrderSignatures
+    )
+        public
+        override
+        returns (uint256[] memory profits, bool[] memory successes)
+    {
+        require(
+            sellOrders.length == buyOrders.length &&
+            sellOrderSignatures.length == buyOrderSignatures.length &&
+            sellOrders.length == sellOrderSignatures.length,
+            "ERC721OrdersFeature::batchMatchERC721Orders/ARRAY_LENGTH_MISMATCH"
+        );
+        profits = new uint256[](sellOrders.length);
+        successes = new bool[](sellOrders.length);
+
+        for (uint256 i = 0; i < sellOrders.length; i++) {
+            bytes memory returnData;
+            // Delegatecall `matchERC721Orders` to catch reverts while
+            // preserving execution context.
+            (successes[i], returnData) = _implementation.delegatecall(
+                abi.encodeWithSelector(
+                    this.matchERC721Orders.selector,
+                    sellOrders[i],
+                    buyOrders[i],
+                    sellOrderSignatures[i],
+                    buyOrderSignatures[i]
+                )
+            );
+            if (successes[i]) {
+                // If the matching succeeded, record the profit.
+                (uint256 profit) = abi.decode(returnData, (uint256));
+                profits[i] = profit;
+            }
+        }
+    }
+
+    /// @dev Callback for the ERC721 `safeTransferFrom` function.
+    ///      This callback can be used to sell an ERC721 asset if
+    ///      a valid ERC721 order, signature and `unwrapNativeToken`
+    ///      are encoded in `data`. This allows takers to sell their
+    ///      ERC721 asset without first calling `setApprovalForAll`.
+    /// @param operator The address which called `safeTransferFrom`.
+    /// @param tokenId The ID of the asset being transferred.
+    /// @param data Additional data with no specified format. If a
+    ///        valid ERC721 order, signature and `unwrapNativeToken`
+    ///        are encoded in `data`, this function will try to fill
+    ///        the order using the received asset.
+    /// @return success The selector of this function (0x150b7a02),
+    ///         indicating that the callback succeeded.
+    function onERC721Received(
+        address operator,
+        address /* from */,
+        uint256 tokenId,
+        bytes calldata data
+    )
+        external
+        override
+        returns (bytes4 success)
+    {
+        // Decode the order, signature, and `unwrapNativeToken` from
+        // `data`. If `data` does not encode such parameters, this
+        // will throw.
+        (
+            LibNFTOrder.ERC721Order memory buyOrder,
+            LibSignature.Signature memory signature,
+            bool unwrapNativeToken
+        ) = abi.decode(
+            data,
+            (LibNFTOrder.ERC721Order, LibSignature.Signature, bool)
+        );
+
+        // `onERC721Received` is called by the ERC721 token contract.
+        // Check that it matches the ERC721 token in the order.
+        if (msg.sender != address(buyOrder.erc721Token)) {
+            LibNFTOrdersRichErrors.ERC721TokenMismatchError(
+                msg.sender,
+                address(buyOrder.erc721Token)
+            ).rrevert();
+        }
+
+        _sellERC721(
+            buyOrder,
+            signature,
+            tokenId,
+            unwrapNativeToken,
+            operator,       // taker
+            address(this),  // owner (we hold the NFT currently)
+            new bytes(0)    // No taker callback
+        );
+
+        return ERC721_RECEIVED_MAGIC_BYTES;
+    }
+
+    /// @dev Approves an ERC721 order on-chain. After pre-signing
+    ///      the order, the `PRESIGNED` signature type will become
+    ///      valid for that order and signer.
+    /// @param order An ERC721 order.
+    function preSignERC721Order(LibNFTOrder.ERC721Order memory order)
+        public
+        override
+    {
+        require(
+            order.maker == msg.sender,
+            "ERC721OrdersFeature::preSignERC721Order/ONLY_MAKER"
+        );
+        bytes32 orderHash = getERC721OrderHash(order);
+        LibERC721OrdersStorage.getStorage().preSigned[orderHash] = true;
+
+        emit ERC721OrderPreSigned(
+            order.direction,
+            order.maker,
+            order.taker,
+            order.expiry,
+            order.nonce,
+            order.erc20Token,
+            order.erc20TokenAmount,
+            order.fees,
+            order.erc721Token,
+            order.erc721TokenId,
+            order.erc721TokenProperties
+        );
+    }
+
+    // Core settlement logic for selling an ERC721 asset.
+    // Used by `sellERC721` and `onERC721Received`.
+    function _sellERC721(
+        LibNFTOrder.ERC721Order memory buyOrder,
+        LibSignature.Signature memory signature,
+        uint256 erc721TokenId,
+        bool unwrapNativeToken,
+        address taker,
+        address currentNftOwner,
+        bytes memory takerCallbackData
+    )
+        private
+    {
+        _sellNFT(
+            buyOrder.asNFTOrder(),
+            signature,
+            SellParams(
+                1, // sell amount
+                erc721TokenId,
+                unwrapNativeToken,
+                taker,
+                currentNftOwner,
+                takerCallbackData
+            )
+        );
+
+        emit ERC721OrderFilled(
+            buyOrder.direction,
+            buyOrder.maker,
+            taker,
+            buyOrder.nonce,
+            buyOrder.erc20Token,
+            buyOrder.erc20TokenAmount,
+            buyOrder.erc721Token,
+            erc721TokenId,
+            address(0)
+        );
+    }
+
+    // Core settlement logic for buying an ERC721 asset.
+    // Used by `buyERC721` and `batchBuyERC721s`.
+    function _buyERC721(
+        LibNFTOrder.ERC721Order memory sellOrder,
+        LibSignature.Signature memory signature,
+        uint256 ethAvailable,
+        bytes memory takerCallbackData
+    )
+        public
+        payable
+    {
+        _buyNFT(
+            sellOrder.asNFTOrder(),
+            signature,
+            BuyParams(
+                1, // buy amount
+                ethAvailable,
+                takerCallbackData
+            )
+        );
+
+        emit ERC721OrderFilled(
+            sellOrder.direction,
+            sellOrder.maker,
+            msg.sender,
+            sellOrder.nonce,
+            sellOrder.erc20Token,
+            sellOrder.erc20TokenAmount,
+            sellOrder.erc721Token,
+            sellOrder.erc721TokenId,
+            address(0)
+        );
+    }
+
+
+    /// @dev Checks whether the given signature is valid for the
+    ///      the given ERC721 order. Reverts if not.
+    /// @param order The ERC721 order.
+    /// @param signature The signature to validate.
+    function validateERC721OrderSignature(
+        LibNFTOrder.ERC721Order memory order,
+        LibSignature.Signature memory signature
+    )
+        public
+        override
+        view
+    {
+        bytes32 orderHash = getERC721OrderHash(order);
+        _validateOrderSignature(orderHash, signature, order.maker);
+    }
+
+    /// @dev Validates that the given signature is valid for the
+    ///      given maker and order hash. Reverts if the signature
+    ///      is not valid.
+    /// @param orderHash The hash of the order that was signed.
+    /// @param signature The signature to check.
+    /// @param maker The maker of the order.
+    function _validateOrderSignature(
+        bytes32 orderHash,
+        LibSignature.Signature memory signature,
+        address maker
+    )
+        internal
+        override
+        view
+    {
+        if (signature.signatureType == LibSignature.SignatureType.PRESIGNED) {
+            // Check if order hash has been pre-signed by the maker.
+            bool isPreSigned = LibERC721OrdersStorage.getStorage().preSigned[orderHash];
+            if (!isPreSigned) {
+                LibNFTOrdersRichErrors.InvalidSignerError(maker, address(0)).rrevert();
+            }
+        } else {
+            address signer = LibSignature.getSignerOfHash(orderHash, signature);
+            if (signer != maker) {
+                LibNFTOrdersRichErrors.InvalidSignerError(maker, signer).rrevert();
+            }
+        }
+    }
+
+    /// @dev Transfers an NFT asset.
+    /// @param token The address of the NFT contract.
+    /// @param from The address currently holding the asset.
+    /// @param to The address to transfer the asset to.
+    /// @param tokenId The ID of the asset to transfer.
+    /// @param amount The amount of the asset to transfer. Always
+    ///        1 for ERC721 assets.
+    function _transferNFTAssetFrom(
+        address token,
+        address from,
+        address to,
+        uint256 tokenId,
+        uint256 amount
+    )
+        internal
+        override
+    {
+        assert(amount == 1);
+        _transferERC721AssetFrom(IERC721Token(token), from, to, tokenId);
+    }
+
+    /// @dev Updates storage to indicate that the given order
+    ///      has been filled by the given amount.
+    /// @param order The order that has been filled.
+    /// @param fillAmount The amount (denominated in the NFT asset)
+    ///        that the order has been filled by.
+    function _updateOrderState(
+        LibNFTOrder.NFTOrder memory order,
+        bytes32 /* orderHash */,
+        uint128 fillAmount
+    )
+        internal
+        override
+    {
+        assert(fillAmount == 1);
+        _setOrderStatusBit(order.maker, order.nonce);
+    }
+
+    function _setOrderStatusBit(address maker, uint256 nonce)
+        private
+    {
+        // The bitvector is indexed by the lower 8 bits of the nonce.
+        uint256 flag = 1 << (nonce & 255);
+        // Update order status bit vector to indicate that the given order
+        // has been cancelled/filled by setting the designated bit to 1.
+        LibERC721OrdersStorage.getStorage().orderStatusByMaker
+            [maker][uint248(nonce >> 8)] |= flag;
+    }
+
+    /// @dev If the given order is buying an ERC721 asset, checks
+    ///      whether or not the given token ID satisfies the required
+    ///      properties specified in the order. If the order does not
+    ///      specify any properties, this function instead checks
+    ///      whether the given token ID matches the ID in the order.
+    ///      Reverts if any checks fail, or if the order is selling
+    ///      an ERC721 asset.
+    /// @param order The ERC721 order.
+    /// @param erc721TokenId The ID of the ERC721 asset.
+    function validateERC721OrderProperties(
+        LibNFTOrder.ERC721Order memory order,
+        uint256 erc721TokenId
+    )
+        public
+        override
+        view
+    {
+        _validateOrderProperties(
+            order.asNFTOrder(),
+            erc721TokenId
+        );
+    }
+
+    /// @dev Get the current status of an ERC721 order.
+    /// @param order The ERC721 order.
+    /// @return status The status of the order.
+    function getERC721OrderStatus(LibNFTOrder.ERC721Order memory order)
+        public
+        override
+        view
+        returns (LibNFTOrder.OrderStatus status)
+    {
+        // Only buy orders with `erc721TokenId` == 0 can be property
+        // orders.
+        if (order.erc721TokenProperties.length > 0 &&
+                (order.direction != LibNFTOrder.TradeDirection.BUY_NFT ||
+                 order.erc721TokenId != 0))
+        {
+            return LibNFTOrder.OrderStatus.INVALID;
+        }
+
+        // Buy orders cannot use ETH as the ERC20 token, since ETH cannot be
+        // transferred from the buyer by a contract.
+        if (order.direction == LibNFTOrder.TradeDirection.BUY_NFT &&
+            address(order.erc20Token) == NATIVE_TOKEN_ADDRESS)
+        {
+            return LibNFTOrder.OrderStatus.INVALID;
+        }
+
+        // Check for expiry.
+        if (order.expiry <= block.timestamp) {
+            return LibNFTOrder.OrderStatus.EXPIRED;
+        }
+
+        // Check `orderStatusByMaker` state variable to see if the order
+        // has been cancelled or previously filled.
+        LibERC721OrdersStorage.Storage storage stor =
+            LibERC721OrdersStorage.getStorage();
+        // `orderStatusByMaker` is indexed by maker and nonce.
+        uint256 orderStatusBitVector =
+            stor.orderStatusByMaker[order.maker][uint248(order.nonce >> 8)];
+        // The bitvector is indexed by the lower 8 bits of the nonce.
+        uint256 flag = 1 << (order.nonce & 255);
+        // If the designated bit is set, the order has been cancelled or
+        // previously filled, so it is now unfillable.
+        if (orderStatusBitVector & flag != 0) {
+            return LibNFTOrder.OrderStatus.UNFILLABLE;
+        }
+
+        // Otherwise, the order is fillable.
+        return LibNFTOrder.OrderStatus.FILLABLE;
+    }
+
+    /// @dev Get the order info for an NFT order.
+    /// @param order The NFT order.
+    /// @return orderInfo Info about the order.
+    function _getOrderInfo(LibNFTOrder.NFTOrder memory order)
+        internal
+        override
+        view
+        returns (LibNFTOrder.OrderInfo memory orderInfo)
+    {
+        LibNFTOrder.ERC721Order memory erc721Order = order.asERC721Order();
+        orderInfo.orderHash = getERC721OrderHash(erc721Order);
+        orderInfo.status = getERC721OrderStatus(erc721Order);
+        orderInfo.orderAmount = 1;
+        orderInfo.remainingAmount = orderInfo.status == LibNFTOrder.OrderStatus.FILLABLE ? 1 : 0;
+    }
+
+    /// @dev Get the EIP-712 hash of an ERC721 order.
+    /// @param order The ERC721 order.
+    /// @return orderHash The order hash.
+    function getERC721OrderHash(LibNFTOrder.ERC721Order memory order)
+        public
+        override
+        view
+        returns (bytes32 orderHash)
+    {
+        return _getEIP712Hash(LibNFTOrder.getERC721OrderStructHash(order));
+    }
+
+    /// @dev Get the order status bit vector for the given
+    ///      maker address and nonce range.
+    /// @param maker The maker of the order.
+    /// @param nonceRange Order status bit vectors are indexed
+    ///        by maker address and the upper 248 bits of the
+    ///        order nonce. We define `nonceRange` to be these
+    ///        248 bits.
+    /// @return bitVector The order status bit vector for the
+    ///         given maker and nonce range.
+    function getERC721OrderStatusBitVector(address maker, uint248 nonceRange)
+        external
+        override
+        view
+        returns (uint256 bitVector)
+    {
+        LibERC721OrdersStorage.Storage storage stor =
+            LibERC721OrdersStorage.getStorage();
+        return stor.orderStatusByMaker[maker][nonceRange];
+    }
+}
--- a/contracts/zero-ex/contracts/src/features/nft_orders/NFTOrders.sol
+++ b/contracts/zero-ex/contracts/src/features/nft_orders/NFTOrders.sol
@@ -0,0 +1,615 @@
+// SPDX-License-Identifier: Apache-2.0
+/*
+
+  Copyright 2021 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 ^0.6;
+pragma experimental ABIEncoderV2;
+
+import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
+import "@0x/contracts-erc20/contracts/src/v06/IEtherTokenV06.sol";
+import "@0x/contracts-utils/contracts/src/v06/LibMathV06.sol";
+import "@0x/contracts-utils/contracts/src/v06/LibSafeMathV06.sol";
+import "../../errors/LibNFTOrdersRichErrors.sol";
+import "../../fixins/FixinCommon.sol";
+import "../../fixins/FixinEIP712.sol";
+import "../../fixins/FixinTokenSpender.sol";
+import "../../migrations/LibMigrate.sol";
+import "../../vendor/IFeeRecipient.sol";
+import "../../vendor/ITakerCallback.sol";
+import "../libs/LibSignature.sol";
+import "../libs/LibNFTOrder.sol";
+
+
+/// @dev Abstract base contract inherited by ERC721OrdersFeature and NFTOrders
+abstract contract NFTOrders is
+    FixinCommon,
+    FixinEIP712,
+    FixinTokenSpender
+{
+    using LibSafeMathV06 for uint256;
+
+    /// @dev Native token pseudo-address.
+    address constant internal NATIVE_TOKEN_ADDRESS = 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE;
+    /// @dev The WETH token contract.
+    IEtherTokenV06 internal immutable WETH;
+
+    /// @dev The magic return value indicating the success of a `receiveZeroExFeeCallback`.
+    bytes4 private constant FEE_CALLBACK_MAGIC_BYTES = IFeeRecipient.receiveZeroExFeeCallback.selector;
+    /// @dev The magic return value indicating the success of a `zeroExTakerCallback`.
+    bytes4 private constant TAKER_CALLBACK_MAGIC_BYTES = ITakerCallback.zeroExTakerCallback.selector;
+
+    constructor(address zeroExAddress, IEtherTokenV06 weth)
+        public
+        FixinEIP712(zeroExAddress)
+    {
+        WETH = weth;
+    }
+
+    struct SellParams {
+        uint128 sellAmount;
+        uint256 tokenId;
+        bool unwrapNativeToken;
+        address taker;
+        address currentNftOwner;
+        bytes takerCallbackData;
+    }
+
+    struct BuyParams {
+        uint128 buyAmount;
+        uint256 ethAvailable;
+        bytes takerCallbackData;
+    }
+
+    // Core settlement logic for selling an NFT asset.
+    function _sellNFT(
+        LibNFTOrder.NFTOrder memory buyOrder,
+        LibSignature.Signature memory signature,
+        SellParams memory params
+    )
+        internal
+        returns (uint256 erc20FillAmount)
+    {
+        LibNFTOrder.OrderInfo memory orderInfo = _getOrderInfo(buyOrder);
+        // Check that the order can be filled.
+        _validateBuyOrder(
+            buyOrder,
+            signature,
+            orderInfo,
+            params.taker,
+            params.tokenId
+        );
+
+        if (params.sellAmount > orderInfo.remainingAmount) {
+            LibNFTOrdersRichErrors.ExceedsRemainingOrderAmount(
+                orderInfo.remainingAmount,
+                params.sellAmount
+            ).rrevert();
+        }
+
+        _updateOrderState(buyOrder, orderInfo.orderHash, params.sellAmount);
+
+        if (params.sellAmount == orderInfo.orderAmount) {
+            erc20FillAmount = buyOrder.erc20TokenAmount;
+        } else {
+            // Rounding favors the order maker.
+            erc20FillAmount = LibMathV06.getPartialAmountFloor(
+                params.sellAmount,
+                orderInfo.orderAmount,
+                buyOrder.erc20TokenAmount
+            );
+        }
+
+        if (params.unwrapNativeToken) {
+            // The ERC20 token must be WETH for it to be unwrapped.
+            if (buyOrder.erc20Token != WETH) {
+                LibNFTOrdersRichErrors.ERC20TokenMismatchError(
+                    address(buyOrder.erc20Token),
+                    address(WETH)
+                ).rrevert();
+            }
+            // Transfer the WETH from the maker to the Exchange Proxy
+            // so we can unwrap it before sending it to the seller.
+            // TODO: Probably safe to just use WETH.transferFrom for some
+            //       small gas savings
+            _transferERC20TokensFrom(
+                WETH,
+                buyOrder.maker,
+                address(this),
+                erc20FillAmount
+            );
+            // Unwrap WETH into ETH.
+            WETH.withdraw(erc20FillAmount);
+            // Send ETH to the seller.
+            _transferEth(payable(params.taker), erc20FillAmount);
+        } else {
+            // Transfer the ERC20 token from the buyer to the seller.
+            _transferERC20TokensFrom(
+                buyOrder.erc20Token,
+                buyOrder.maker,
+                params.taker,
+                erc20FillAmount
+            );
+        }
+
+        if (params.takerCallbackData.length > 0) {
+            require(
+                params.taker != address(this),
+                "NFTOrders::_sellNFT/CANNOT_CALLBACK_SELF"
+            );
+            // Invoke the callback
+            bytes4 callbackResult = ITakerCallback(params.taker)
+                .zeroExTakerCallback(orderInfo.orderHash, params.takerCallbackData);
+            // Check for the magic success bytes
+            require(
+                callbackResult == TAKER_CALLBACK_MAGIC_BYTES,
+                "NFTOrders::_sellNFT/CALLBACK_FAILED"
+            );
+        }
+
+        // Transfer the NFT asset to the buyer.
+        // If this function is called from the
+        // `onNFTReceived` callback the Exchange Proxy
+        // holds the asset. Otherwise, transfer it from
+        // the seller.
+        _transferNFTAssetFrom(
+            buyOrder.nft,
+            params.currentNftOwner,
+            buyOrder.maker,
+            params.tokenId,
+            params.sellAmount
+        );
+
+        // The buyer pays the order fees.
+        _payFees(
+            buyOrder,
+            buyOrder.maker,
+            params.sellAmount,
+            orderInfo.orderAmount,
+            false
+        );
+    }
+
+    // Core settlement logic for buying an NFT asset.
+    function _buyNFT(
+        LibNFTOrder.NFTOrder memory sellOrder,
+        LibSignature.Signature memory signature,
+        BuyParams memory params
+    )
+        internal
+        returns (uint256 erc20FillAmount)
+    {
+        LibNFTOrder.OrderInfo memory orderInfo = _getOrderInfo(sellOrder);
+        // Check that the order can be filled.
+        _validateSellOrder(
+            sellOrder,
+            signature,
+            orderInfo,
+            msg.sender
+        );
+
+        if (params.buyAmount > orderInfo.remainingAmount) {
+            LibNFTOrdersRichErrors.ExceedsRemainingOrderAmount(
+                orderInfo.remainingAmount,
+                params.buyAmount
+            ).rrevert();
+        }
+
+        _updateOrderState(sellOrder, orderInfo.orderHash, params.buyAmount);
+
+        if (params.buyAmount == orderInfo.orderAmount) {
+            erc20FillAmount = sellOrder.erc20TokenAmount;
+        } else {
+            // Rounding favors the order maker.
+            erc20FillAmount = LibMathV06.getPartialAmountCeil(
+                params.buyAmount,
+                orderInfo.orderAmount,
+                sellOrder.erc20TokenAmount
+            );
+        }
+
+        // Transfer the NFT asset to the buyer (`msg.sender`).
+        _transferNFTAssetFrom(
+            sellOrder.nft,
+            sellOrder.maker,
+            msg.sender,
+            sellOrder.nftId,
+            params.buyAmount
+        );
+
+        uint256 ethAvailable = params.ethAvailable;
+        if (params.takerCallbackData.length > 0) {
+            require(
+                msg.sender != address(this),
+                "NFTOrders::_buyNFT/CANNOT_CALLBACK_SELF"
+            );
+            uint256 ethBalanceBeforeCallback = address(this).balance;
+            // Invoke the callback
+            bytes4 callbackResult = ITakerCallback(msg.sender)
+                .zeroExTakerCallback(orderInfo.orderHash, params.takerCallbackData);
+            // Update `ethAvailable` with amount acquired during
+            // the callback
+            ethAvailable = ethAvailable.safeAdd(
+                address(this).balance.safeSub(ethBalanceBeforeCallback)
+            );
+            // Check for the magic success bytes
+            require(
+                callbackResult == TAKER_CALLBACK_MAGIC_BYTES,
+                "NFTOrders::_buyNFT/CALLBACK_FAILED"
+            );
+        }
+
+        if (address(sellOrder.erc20Token) == NATIVE_TOKEN_ADDRESS) {
+            // Transfer ETH to the seller.
+            _transferEth(payable(sellOrder.maker), erc20FillAmount);
+            // Fees are paid from the EP's current balance of ETH.
+            _payEthFees(
+                sellOrder,
+                params.buyAmount,
+                orderInfo.orderAmount,
+                erc20FillAmount,
+                ethAvailable
+            );
+        } else if (sellOrder.erc20Token == WETH) {
+            // If there is enough ETH available, fill the WETH order
+            // (including fees) using that ETH.
+            // Otherwise, transfer WETH from the taker.
+            if (ethAvailable >= erc20FillAmount) {
+                // Wrap ETH.
+                WETH.deposit{value: erc20FillAmount}();
+                // TODO: Probably safe to just use WETH.transfer for some
+                //       small gas savings
+                // Transfer WETH to the seller.
+                _transferERC20Tokens(
+                    WETH,
+                    sellOrder.maker,
+                    erc20FillAmount
+                );
+                // Fees are paid from the EP's current balance of ETH.
+                _payEthFees(
+                    sellOrder,
+                    params.buyAmount,
+                    orderInfo.orderAmount,
+                    erc20FillAmount,
+                    ethAvailable
+                );
+            } else {
+                // Transfer WETH from the buyer to the seller.
+                _transferERC20TokensFrom(
+                    sellOrder.erc20Token,
+                    msg.sender,
+                    sellOrder.maker,
+                    erc20FillAmount
+                );
+                // The buyer pays fees using WETH.
+                _payFees(
+                    sellOrder,
+                    msg.sender,
+                    params.buyAmount,
+                    orderInfo.orderAmount,
+                    false
+                );
+            }
+        } else {
+            // Transfer ERC20 token from the buyer to the seller.
+            _transferERC20TokensFrom(
+                sellOrder.erc20Token,
+                msg.sender,
+                sellOrder.maker,
+                erc20FillAmount
+            );
+            // The buyer pays fees.
+            _payFees(
+                sellOrder,
+                msg.sender,
+                params.buyAmount,
+                orderInfo.orderAmount,
+                false
+            );
+        }
+    }
+
+    function _validateSellOrder(
+        LibNFTOrder.NFTOrder memory sellOrder,
+        LibSignature.Signature memory signature,
+        LibNFTOrder.OrderInfo memory orderInfo,
+        address taker
+    )
+        internal
+        view
+    {
+        // Order must be selling the NFT asset.
+        require(
+            sellOrder.direction == LibNFTOrder.TradeDirection.SELL_NFT,
+            "NFTOrders::_validateSellOrder/WRONG_TRADE_DIRECTION"
+        );
+        // Taker must match the order taker, if one is specified.
+        if (sellOrder.taker != address(0) && sellOrder.taker != taker) {
+            LibNFTOrdersRichErrors.OnlyTakerError(taker, sellOrder.taker).rrevert();
+        }
+        // Check that the order is valid and has not expired, been cancelled,
+        // or been filled.
+        if (orderInfo.status != LibNFTOrder.OrderStatus.FILLABLE) {
+            LibNFTOrdersRichErrors.OrderNotFillableError(
+                sellOrder.maker,
+                sellOrder.nonce,
+                uint8(orderInfo.status)
+            ).rrevert();
+        }
+
+        // Check the signature.
+        _validateOrderSignature(orderInfo.orderHash, signature, sellOrder.maker);
+    }
+
+    function _validateBuyOrder(
+        LibNFTOrder.NFTOrder memory buyOrder,
+        LibSignature.Signature memory signature,
+        LibNFTOrder.OrderInfo memory orderInfo,
+        address taker,
+        uint256 tokenId
+    )
+        internal
+        view
+    {
+        // Order must be buying the NFT asset.
+        require(
+            buyOrder.direction == LibNFTOrder.TradeDirection.BUY_NFT,
+            "NFTOrders::_validateBuyOrder/WRONG_TRADE_DIRECTION"
+        );
+        // The ERC20 token cannot be ETH.
+        require(
+            address(buyOrder.erc20Token) != NATIVE_TOKEN_ADDRESS,
+            "NFTOrders::_validateBuyOrder/NATIVE_TOKEN_NOT_ALLOWED"
+        );
+        // Taker must match the order taker, if one is specified.
+        if (buyOrder.taker != address(0) && buyOrder.taker != taker) {
+            LibNFTOrdersRichErrors.OnlyTakerError(taker, buyOrder.taker).rrevert();
+        }
+        // Check that the order is valid and has not expired, been cancelled,
+        // or been filled.
+        if (orderInfo.status != LibNFTOrder.OrderStatus.FILLABLE) {
+            LibNFTOrdersRichErrors.OrderNotFillableError(
+                buyOrder.maker,
+                buyOrder.nonce,
+                uint8(orderInfo.status)
+            ).rrevert();
+        }
+        // Check that the asset with the given token ID satisfies the properties
+        // specified by the order.
+        _validateOrderProperties(buyOrder, tokenId);
+        // Check the signature.
+        _validateOrderSignature(orderInfo.orderHash, signature, buyOrder.maker);
+    }
+
+    function _payEthFees(
+        LibNFTOrder.NFTOrder memory order,
+        uint128 fillAmount,
+        uint128 orderAmount,
+        uint256 ethSpent,
+        uint256 ethAvailable
+    )
+        private
+    {
+        // Pay fees using ETH.
+        uint256 ethFees = _payFees(
+            order,
+            address(this),
+            fillAmount,
+            orderAmount,
+            true
+        );
+        // Update amount of ETH spent.
+        ethSpent = ethSpent.safeAdd(ethFees);
+        if (ethSpent > ethAvailable) {
+            LibNFTOrdersRichErrors.OverspentEthError(
+                ethSpent,
+                ethAvailable
+            ).rrevert();
+        }
+    }
+
+    function _payFees(
+        LibNFTOrder.NFTOrder memory order,
+        address payer,
+        uint128 fillAmount,
+        uint128 orderAmount,
+        bool useNativeToken
+    )
+        internal
+        returns (uint256 totalFeesPaid)
+    {
+        // Make assertions about ETH case
+        if (useNativeToken) {
+            assert(payer == address(this));
+            assert(
+                order.erc20Token == WETH ||
+                address(order.erc20Token) == NATIVE_TOKEN_ADDRESS
+            );
+        }
+
+        for (uint256 i = 0; i < order.fees.length; i++) {
+            LibNFTOrder.Fee memory fee = order.fees[i];
+
+            require(
+                fee.recipient != address(this),
+                "NFTOrders::_payFees/RECIPIENT_CANNOT_BE_EXCHANGE_PROXY"
+            );
+
+            uint256 feeFillAmount;
+            if (fillAmount == orderAmount) {
+                feeFillAmount = fee.amount;
+            } else {
+                // Round against the fee recipient
+                feeFillAmount = LibMathV06.getPartialAmountFloor(
+                    fillAmount,
+                    orderAmount,
+                    fee.amount
+                );
+            }
+            if (feeFillAmount == 0) {
+                continue;
+            }
+
+            if (useNativeToken) {
+                // Transfer ETH to the fee recipient.
+                _transferEth(payable(fee.recipient), feeFillAmount);
+            } else {
+                // Transfer ERC20 token from payer to recipient.
+                _transferERC20TokensFrom(
+                    order.erc20Token,
+                    payer,
+                    fee.recipient,
+                    feeFillAmount
+                );
+            }
+            // Note that the fee callback is _not_ called if zero
+            // `feeData` is provided. If `feeData` is provided, we assume
+            // the fee recipient is a contract that implements the
+            // `IFeeRecipient` interface.
+            if (fee.feeData.length > 0) {
+                // Invoke the callback
+                bytes4 callbackResult = IFeeRecipient(fee.recipient).receiveZeroExFeeCallback(
+                    useNativeToken ? NATIVE_TOKEN_ADDRESS : address(order.erc20Token),
+                    feeFillAmount,
+                    fee.feeData
+                );
+                // Check for the magic success bytes
+                require(
+                    callbackResult == FEE_CALLBACK_MAGIC_BYTES,
+                    "NFTOrders::_payFees/CALLBACK_FAILED"
+                );
+            }
+            // Sum the fees paid
+            totalFeesPaid = totalFeesPaid.safeAdd(feeFillAmount);
+        }
+    }
+
+    /// @dev If the given order is buying an NFT asset, checks
+    ///      whether or not the given token ID satisfies the required
+    ///      properties specified in the order. If the order does not
+    ///      specify any properties, this function instead checks
+    ///      whether the given token ID matches the ID in the order.
+    ///      Reverts if any checks fail, or if the order is selling
+    ///      an NFT asset.
+    /// @param order The NFT order.
+    /// @param tokenId The ID of the NFT asset.
+    function _validateOrderProperties(
+        LibNFTOrder.NFTOrder memory order,
+        uint256 tokenId
+    )
+        internal
+        view
+    {
+        // Order must be buying an NFT asset to have properties.
+        require(
+            order.direction == LibNFTOrder.TradeDirection.BUY_NFT,
+            "NFTOrders::_validateOrderProperties/WRONG_TRADE_DIRECTION"
+        );
+
+        // If no properties are specified, check that the given
+        // `tokenId` matches the one specified in the order.
+        if (order.nftProperties.length == 0) {
+            if (tokenId != order.nftId) {
+                LibNFTOrdersRichErrors.TokenIdMismatchError(
+                    tokenId,
+                    order.nftId
+                ).rrevert();
+            }
+        } else {
+            // Validate each property
+            for (uint256 i = 0; i < order.nftProperties.length; i++) {
+                LibNFTOrder.Property memory property = order.nftProperties[i];
+                // `address(0)` is interpreted as a no-op. Any token ID
+                // will satisfy a property with `propertyValidator == address(0)`.
+                if (address(property.propertyValidator) == address(0)) {
+                    continue;
+                }
+
+                // Call the property validator and throw a descriptive error
+                // if the call reverts.
+                try property.propertyValidator.validateProperty(
+                    order.nft,
+                    tokenId,
+                    property.propertyData
+                ) {} catch (bytes memory errorData) {
+                    LibNFTOrdersRichErrors.PropertyValidationFailedError(
+                        address(property.propertyValidator),
+                        order.nft,
+                        tokenId,
+                        property.propertyData,
+                        errorData
+                    ).rrevert();
+                }
+            }
+        }
+    }
+
+    /// @dev Validates that the given signature is valid for the
+    ///      given maker and order hash. Reverts if the signature
+    ///      is not valid.
+    /// @param orderHash The hash of the order that was signed.
+    /// @param signature The signature to check.
+    /// @param maker The maker of the order.
+    function _validateOrderSignature(
+        bytes32 orderHash,
+        LibSignature.Signature memory signature,
+        address maker
+    )
+        internal
+        virtual
+        view;
+
+    /// @dev Transfers an NFT asset.
+    /// @param token The address of the NFT contract.
+    /// @param from The address currently holding the asset.
+    /// @param to The address to transfer the asset to.
+    /// @param tokenId The ID of the asset to transfer.
+    /// @param amount The amount of the asset to transfer. Always
+    ///        1 for ERC721 assets.
+    function _transferNFTAssetFrom(
+        address token,
+        address from,
+        address to,
+        uint256 tokenId,
+        uint256 amount
+    )
+        internal
+        virtual;
+
+    /// @dev Updates storage to indicate that the given order
+    ///      has been filled by the given amount.
+    /// @param order The order that has been filled.
+    /// @param orderHash The hash of `order`.
+    /// @param fillAmount The amount (denominated in the NFT asset)
+    ///        that the order has been filled by.
+    function _updateOrderState(
+        LibNFTOrder.NFTOrder memory order,
+        bytes32 orderHash,
+        uint128 fillAmount
+    )
+        internal
+        virtual;
+
+    /// @dev Get the order info for an NFT order.
+    /// @param order The NFT order.
+    /// @return orderInfo Info about the order.
+    function _getOrderInfo(LibNFTOrder.NFTOrder memory order)
+        internal
+        virtual
+        view
+        returns (LibNFTOrder.OrderInfo memory orderInfo);
+}
--- a/contracts/zero-ex/contracts/src/fixins/FixinERC1155Spender.sol
+++ b/contracts/zero-ex/contracts/src/fixins/FixinERC1155Spender.sol
@@ -0,0 +1,79 @@
+// SPDX-License-Identifier: Apache-2.0
+/*
+
+  Copyright 2020 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 ^0.6;
+pragma experimental ABIEncoderV2;
+
+import "@0x/contracts-utils/contracts/src/v06/LibSafeMathV06.sol";
+import "../vendor/IERC1155Token.sol";
+
+
+/// @dev Helpers for moving ERC1155 assets around.
+abstract contract FixinERC1155Spender {
+
+    // Mask of the lower 20 bytes of a bytes32.
+    uint256 constant private ADDRESS_MASK = 0x000000000000000000000000ffffffffffffffffffffffffffffffffffffffff;
+
+    /// @dev Transfers an ERC1155 asset from `owner` to `to`.
+    /// @param token The address of the ERC1155 token contract.
+    /// @param owner The owner of the asset.
+    /// @param to The recipient of the asset.
+    /// @param tokenId The token ID of the asset to transfer.
+    /// @param amount The amount of the asset to transfer.
+    function _transferERC1155AssetFrom(
+        IERC1155Token token,
+        address owner,
+        address to,
+        uint256 tokenId,
+        uint256 amount
+    )
+        internal
+    {
+        require(address(token) != address(this), "FixinERC1155Spender/CANNOT_INVOKE_SELF");
+
+        assembly {
+            let ptr := mload(0x40) // free memory pointer
+
+            // selector for safeTransferFrom(address,address,uint256,uint256,bytes)
+            mstore(ptr, 0xf242432a00000000000000000000000000000000000000000000000000000000)
+            mstore(add(ptr, 0x04), and(owner, ADDRESS_MASK))
+            mstore(add(ptr, 0x24), and(to, ADDRESS_MASK))
+            mstore(add(ptr, 0x44), tokenId)
+            mstore(add(ptr, 0x64), amount)
+            mstore(add(ptr, 0x84), 0xa0)
+            mstore(add(ptr, 0xa4), 0)
+
+            let success := call(
+                gas(),
+                and(token, ADDRESS_MASK),
+                0,
+                ptr,
+                0xc4,
+                0,
+                0
+            )
+
+            if iszero(success) {
+                let rdsize := returndatasize()
+                returndatacopy(ptr, 0, rdsize)
+                revert(ptr, rdsize)
+            }
+        }
+    }
+}
--- a/contracts/zero-ex/contracts/src/fixins/FixinERC721Spender.sol
+++ b/contracts/zero-ex/contracts/src/fixins/FixinERC721Spender.sol
@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: Apache-2.0
+/*
+
+  Copyright 2020 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 ^0.6;
+pragma experimental ABIEncoderV2;
+
+import "@0x/contracts-utils/contracts/src/v06/LibSafeMathV06.sol";
+import "../vendor/IERC721Token.sol";
+
+
+/// @dev Helpers for moving ERC721 assets around.
+abstract contract FixinERC721Spender {
+
+    // Mask of the lower 20 bytes of a bytes32.
+    uint256 constant private ADDRESS_MASK = 0x000000000000000000000000ffffffffffffffffffffffffffffffffffffffff;
+
+    /// @dev Transfers an ERC721 asset from `owner` to `to`.
+    /// @param token The address of the ERC721 token contract.
+    /// @param owner The owner of the asset.
+    /// @param to The recipient of the asset.
+    /// @param tokenId The token ID of the asset to transfer.
+    function _transferERC721AssetFrom(
+        IERC721Token token,
+        address owner,
+        address to,
+        uint256 tokenId
+    )
+        internal
+    {
+        require(address(token) != address(this), "FixinERC721Spender/CANNOT_INVOKE_SELF");
+
+        assembly {
+            let ptr := mload(0x40) // free memory pointer
+
+            // selector for transferFrom(address,address,uint256)
+            mstore(ptr, 0x23b872dd00000000000000000000000000000000000000000000000000000000)
+            mstore(add(ptr, 0x04), and(owner, ADDRESS_MASK))
+            mstore(add(ptr, 0x24), and(to, ADDRESS_MASK))
+            mstore(add(ptr, 0x44), tokenId)
+
+            let success := call(
+                gas(),
+                and(token, ADDRESS_MASK),
+                0,
+                ptr,
+                0x64,
+                0,
+                0
+            )
+
+            if iszero(success) {
+                let rdsize := returndatasize()
+                returndatacopy(ptr, 0, rdsize)
+                revert(ptr, rdsize)
+            }
+        }
+    }
+}
--- a/contracts/zero-ex/contracts/src/fixins/FixinTokenSpender.sol
+++ b/contracts/zero-ex/contracts/src/fixins/FixinTokenSpender.sol
@@ -20,7 +20,7 @@
 pragma solidity ^0.6.5;
 pragma experimental ABIEncoderV2;

-import "@0x/contracts-erc20/contracts/src/v06/IEtherTokenV06.sol";
+import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
 import "@0x/contracts-utils/contracts/src/v06/LibSafeMathV06.sol";


@@ -141,6 +141,20 @@ abstract contract FixinTokenSpender {
        }
    }

+
+    /// @dev Transfers some amount of ETH to the given recipient and
+    ///      reverts if the transfer fails.
+    /// @param recipient The recipient of the ETH.
+    /// @param amount The amount of ETH to transfer.
+    function _transferEth(address payable recipient, uint256 amount)
+        internal
+    {
+        if (amount > 0) {
+            (bool success,) = recipient.call{value: amount}("");
+            require(success, "FixinTokenSpender::_transferEth/TRANSFER_FAILED");
+        }
+    }
+
    /// @dev Gets the maximum amount of an ERC20 token `token` that can be
    ///      pulled from `owner` by this address.
    /// @param token The token to spend.
--- a/contracts/zero-ex/contracts/src/storage/LibERC1155OrdersStorage.sol
+++ b/contracts/zero-ex/contracts/src/storage/LibERC1155OrdersStorage.sol
@@ -0,0 +1,55 @@
+// SPDX-License-Identifier: Apache-2.0
+/*
+
+  Copyright 2020 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 ^0.6;
+pragma experimental ABIEncoderV2;
+
+import "./LibStorage.sol";
+
+
+/// @dev Storage helpers for `ERC1155OrdersFeature`.
+library LibERC1155OrdersStorage {
+
+    struct OrderState {
+        // The amount (denominated in the ERC1155 asset)
+        // that the order has been filled by.
+        uint128 filledAmount;
+        // Whether the order has been pre-signed.
+        bool preSigned;
+    }
+
+    /// @dev Storage bucket for this feature.
+    struct Storage {
+        // Mapping from order hash to order state:
+        mapping(bytes32 => OrderState) orderState;
+        // maker => nonce range => order cancellation bit vector
+        mapping(address => mapping(uint248 => uint256)) orderCancellationByMaker;
+    }
+
+    /// @dev Get the storage bucket for this contract.
+    function getStorage() internal pure returns (Storage storage stor) {
+        uint256 storageSlot = LibStorage.getStorageSlot(
+            LibStorage.StorageId.ERC1155Orders
+        );
+        // Dip into assembly to change the slot pointed to by the local
+        // variable `stor`.
+        // See https://solidity.readthedocs.io/en/v0.6.8/assembly.html?highlight=slot#access-to-external-variables-functions-and-libraries
+        assembly { stor_slot := storageSlot }
+    }
+}
--- a/contracts/zero-ex/contracts/src/storage/LibERC721OrdersStorage.sol
+++ b/contracts/zero-ex/contracts/src/storage/LibERC721OrdersStorage.sol
@@ -0,0 +1,47 @@
+// SPDX-License-Identifier: Apache-2.0
+/*
+
+  Copyright 2020 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 ^0.6;
+pragma experimental ABIEncoderV2;
+
+import "./LibStorage.sol";
+
+
+/// @dev Storage helpers for `ERC721OrdersFeature`.
+library LibERC721OrdersStorage {
+
+    /// @dev Storage bucket for this feature.
+    struct Storage {
+        // maker => nonce range => order status bit vector
+        mapping(address => mapping(uint248 => uint256)) orderStatusByMaker;
+        // order hash => isSigned
+        mapping(bytes32 => bool) preSigned;
+    }
+
+    /// @dev Get the storage bucket for this contract.
+    function getStorage() internal pure returns (Storage storage stor) {
+        uint256 storageSlot = LibStorage.getStorageSlot(
+            LibStorage.StorageId.ERC721Orders
+        );
+        // Dip into assembly to change the slot pointed to by the local
+        // variable `stor`.
+        // See https://solidity.readthedocs.io/en/v0.6.8/assembly.html?highlight=slot#access-to-external-variables-functions-and-libraries
+        assembly { stor_slot := storageSlot }
+    }
+}
--- a/contracts/zero-ex/contracts/src/storage/LibStorage.sol
+++ b/contracts/zero-ex/contracts/src/storage/LibStorage.sol
@@ -17,7 +17,7 @@

 */

-pragma solidity ^0.6.5;
+pragma solidity ^0.6;
 pragma experimental ABIEncoderV2;


@@ -39,7 +39,9 @@ library LibStorage {
        MetaTransactions,
        ReentrancyGuard,
        NativeOrders,
-        OtcOrders
+        OtcOrders,
+        ERC721Orders,
+        ERC1155Orders
    }

    /// @dev Get the storage slot given a storage ID. We assign unique, well-spaced
--- a/contracts/zero-ex/contracts/src/vendor/IERC1155Token.sol
+++ b/contracts/zero-ex/contracts/src/vendor/IERC1155Token.sol
@@ -0,0 +1,151 @@
+// SPDX-License-Identifier: Apache-2.0
+/*
+
+  Copyright 2022 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 ^0.6;
+pragma experimental ABIEncoderV2;
+
+
+interface IERC1155Token {
+
+    /// @dev Either TransferSingle or TransferBatch MUST emit when tokens are transferred,
+    ///      including zero value transfers as well as minting or burning.
+    /// Operator will always be msg.sender.
+    /// Either event from address `0x0` signifies a minting operation.
+    /// An event to address `0x0` signifies a burning or melting operation.
+    /// The total value transferred from address 0x0 minus the total value transferred to 0x0 may
+    /// be used by clients and exchanges to be added to the "circulating supply" for a given token ID.
+    /// To define a token ID with no initial balance, the contract SHOULD emit the TransferSingle event
+    /// from `0x0` to `0x0`, with the token creator as `_operator`.
+    event TransferSingle(
+        address indexed operator,
+        address indexed from,
+        address indexed to,
+        uint256 id,
+        uint256 value
+    );
+
+    /// @dev Either TransferSingle or TransferBatch MUST emit when tokens are transferred,
+    ///      including zero value transfers as well as minting or burning.
+    ///Operator will always be msg.sender.
+    /// Either event from address `0x0` signifies a minting operation.
+    /// An event to address `0x0` signifies a burning or melting operation.
+    /// The total value transferred from address 0x0 minus the total value transferred to 0x0 may
+    /// be used by clients and exchanges to be added to the "circulating supply" for a given token ID.
+    /// To define multiple token IDs with no initial balance, this SHOULD emit the TransferBatch event
+    /// from `0x0` to `0x0`, with the token creator as `_operator`.
+    event TransferBatch(
+        address indexed operator,
+        address indexed from,
+        address indexed to,
+        uint256[] ids,
+        uint256[] values
+    );
+
+    /// @dev MUST emit when an approval is updated.
+    event ApprovalForAll(
+        address indexed owner,
+        address indexed operator,
+        bool approved
+    );
+
+    /// @dev MUST emit when the URI is updated for a token ID.
+    /// URIs are defined in RFC 3986.
+    /// The URI MUST point a JSON file that conforms to the "ERC-1155 Metadata JSON Schema".
+    event URI(
+        string value,
+        uint256 indexed id
+    );
+
+    /// @notice Transfers value amount of an _id from the _from address to the _to address specified.
+    /// @dev MUST emit TransferSingle event on success.
+    /// Caller must be approved to manage the _from account's tokens (see isApprovedForAll).
+    /// MUST throw if `_to` is the zero address.
+    /// MUST throw if balance of sender for token `_id` is lower than the `_value` sent.
+    /// MUST throw on any other error.
+    /// When transfer is complete, this function MUST check if `_to` is a smart contract (code size > 0).
+    /// If so, it MUST call `onERC1155Received` on `_to` and revert if the return value
+    /// is not `bytes4(keccak256("onERC1155Received(address,address,uint256,uint256,bytes)"))`.
+    /// @param from    Source address
+    /// @param to      Target address
+    /// @param id      ID of the token type
+    /// @param value   Transfer amount
+    /// @param data    Additional data with no specified format, sent in call to `_to`
+    function safeTransferFrom(
+        address from,
+        address to,
+        uint256 id,
+        uint256 value,
+        bytes calldata data
+    )
+        external;
+
+    /// @notice Send multiple types of Tokens from a 3rd party in one transfer (with safety call).
+    /// @dev MUST emit TransferBatch event on success.
+    /// Caller must be approved to manage the _from account's tokens (see isApprovedForAll).
+    /// MUST throw if `_to` is the zero address.
+    /// MUST throw if length of `_ids` is not the same as length of `_values`.
+    ///  MUST throw if any of the balance of sender for token `_ids` is lower than the respective `_values` sent.
+    /// MUST throw on any other error.
+    /// When transfer is complete, this function MUST check if `_to` is a smart contract (code size > 0).
+    /// If so, it MUST call `onERC1155BatchReceived` on `_to` and revert if the return value
+    /// is not `bytes4(keccak256("onERC1155BatchReceived(address,address,uint256[],uint256[],bytes)"))`.
+    /// @param from    Source addresses
+    /// @param to      Target addresses
+    /// @param ids     IDs of each token type
+    /// @param values  Transfer amounts per token type
+    /// @param data    Additional data with no specified format, sent in call to `_to`
+    function safeBatchTransferFrom(
+        address from,
+        address to,
+        uint256[] calldata ids,
+        uint256[] calldata values,
+        bytes calldata data
+    )
+        external;
+
+    /// @notice Enable or disable approval for a third party ("operator") to manage all of the caller's tokens.
+    /// @dev MUST emit the ApprovalForAll event on success.
+    /// @param operator  Address to add to the set of authorized operators
+    /// @param approved  True if the operator is approved, false to revoke approval
+    function setApprovalForAll(address operator, bool approved) external;
+
+    /// @notice Queries the approval status of an operator for a given owner.
+    /// @param owner        The owner of the Tokens
+    /// @param operator     Address of authorized operator
+    /// @return isApproved  True if the operator is approved, false if not
+    function isApprovedForAll(address owner, address operator) external view returns (bool isApproved);
+
+    /// @notice Get the balance of an account's Tokens.
+    /// @param owner     The address of the token holder
+    /// @param id        ID of the Token
+    /// @return balance  The _owner's balance of the Token type requested
+    function balanceOf(address owner, uint256 id) external view returns (uint256 balance);
+
+    /// @notice Get the balance of multiple account/token pairs
+    /// @param owners      The addresses of the token holders
+    /// @param ids         ID of the Tokens
+    /// @return balances_  The _owner's balance of the Token types requested
+    function balanceOfBatch(
+        address[] calldata owners,
+        uint256[] calldata ids
+    )
+        external
+        view
+        returns (uint256[] memory balances_);
+}
--- a/contracts/zero-ex/contracts/src/vendor/IERC721Token.sol
+++ b/contracts/zero-ex/contracts/src/vendor/IERC721Token.sol
@@ -0,0 +1,159 @@
+// SPDX-License-Identifier: Apache-2.0
+/*
+
+  Copyright 2021 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 ^0.6;
+
+
+interface IERC721Token {
+
+    /// @dev This emits when ownership of any NFT changes by any mechanism.
+    ///      This event emits when NFTs are created (`from` == 0) and destroyed
+    ///      (`to` == 0). Exception: during contract creation, any number of NFTs
+    ///      may be created and assigned without emitting Transfer. At the time of
+    ///      any transfer, the approved address for that NFT (if any) is reset to none.
+    event Transfer(
+        address indexed _from,
+        address indexed _to,
+        uint256 indexed _tokenId
+    );
+
+    /// @dev This emits when the approved address for an NFT is changed or
+    ///      reaffirmed. The zero address indicates there is no approved address.
+    ///      When a Transfer event emits, this also indicates that the approved
+    ///      address for that NFT (if any) is reset to none.
+    event Approval(
+        address indexed _owner,
+        address indexed _approved,
+        uint256 indexed _tokenId
+    );
+
+    /// @dev This emits when an operator is enabled or disabled for an owner.
+    ///      The operator can manage all NFTs of the owner.
+    event ApprovalForAll(
+        address indexed _owner,
+        address indexed _operator,
+        bool _approved
+    );
+
+    /// @notice Transfers the ownership of an NFT from one address to another address
+    /// @dev Throws unless `msg.sender` is the current owner, an authorized
+    ///      perator, or the approved address for this NFT. Throws if `_from` is
+    ///      not the current owner. Throws if `_to` is the zero address. Throws if
+    ///      `_tokenId` is not a valid NFT. When transfer is complete, this function
+    ///      checks if `_to` is a smart contract (code size > 0). If so, it calls
+    ///      `onERC721Received` on `_to` and throws if the return value is not
+    ///      `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`.
+    /// @param _from The current owner of the NFT
+    /// @param _to The new owner
+    /// @param _tokenId The NFT to transfer
+    /// @param _data Additional data with no specified format, sent in call to `_to`
+    function safeTransferFrom(
+        address _from,
+        address _to,
+        uint256 _tokenId,
+        bytes calldata _data
+    )
+        external;
+
+    /// @notice Transfers the ownership of an NFT from one address to another address
+    /// @dev This works identically to the other function with an extra data parameter,
+    ///      except this function just sets data to "".
+    /// @param _from The current owner of the NFT
+    /// @param _to The new owner
+    /// @param _tokenId The NFT to transfer
+    function safeTransferFrom(
+        address _from,
+        address _to,
+        uint256 _tokenId
+    )
+        external;
+
+    /// @notice Change or reaffirm the approved address for an NFT
+    /// @dev The zero address indicates there is no approved address.
+    ///      Throws unless `msg.sender` is the current NFT owner, or an authorized
+    ///      operator of the current owner.
+    /// @param _approved The new approved NFT controller
+    /// @param _tokenId The NFT to approve
+    function approve(address _approved, uint256 _tokenId)
+        external;
+
+    /// @notice Enable or disable approval for a third party ("operator") to manage
+    ///         all of `msg.sender`'s assets
+    /// @dev Emits the ApprovalForAll event. The contract MUST allow
+    ///      multiple operators per owner.
+    /// @param _operator Address to add to the set of authorized operators
+    /// @param _approved True if the operator is approved, false to revoke approval
+    function setApprovalForAll(address _operator, bool _approved)
+        external;
+
+    /// @notice Count all NFTs assigned to an owner
+    /// @dev NFTs assigned to the zero address are considered invalid, and this
+    ///      function throws for queries about the zero address.
+    /// @param _owner An address for whom to query the balance
+    /// @return The number of NFTs owned by `_owner`, possibly zero
+    function balanceOf(address _owner)
+        external
+        view
+        returns (uint256);
+
+    /// @notice Transfer ownership of an NFT -- THE CALLER IS RESPONSIBLE
+    ///         TO CONFIRM THAT `_to` IS CAPABLE OF RECEIVING NFTS OR ELSE
+    ///         THEY MAY BE PERMANENTLY LOST
+    /// @dev Throws unless `msg.sender` is the current owner, an authorized
+    ///      operator, or the approved address for this NFT. Throws if `_from` is
+    ///      not the current owner. Throws if `_to` is the zero address. Throws if
+    ///      `_tokenId` is not a valid NFT.
+    /// @param _from The current owner of the NFT
+    /// @param _to The new owner
+    /// @param _tokenId The NFT to transfer
+    function transferFrom(
+        address _from,
+        address _to,
+        uint256 _tokenId
+    )
+        external;
+
+    /// @notice Find the owner of an NFT
+    /// @dev NFTs assigned to zero address are considered invalid, and queries
+    ///      about them do throw.
+    /// @param _tokenId The identifier for an NFT
+    /// @return The address of the owner of the NFT
+    function ownerOf(uint256 _tokenId)
+        external
+        view
+        returns (address);
+
+    /// @notice Get the approved address for a single NFT
+    /// @dev Throws if `_tokenId` is not a valid NFT.
+    /// @param _tokenId The NFT to find the approved address for
+    /// @return The approved address for this NFT, or the zero address if there is none
+    function getApproved(uint256 _tokenId)
+        external
+        view
+        returns (address);
+
+    /// @notice Query if an address is an authorized operator for another address
+    /// @param _owner The address that owns the NFTs
+    /// @param _operator The address that acts on behalf of the owner
+    /// @return True if `_operator` is an approved operator for `_owner`, false otherwise
+    function isApprovedForAll(address _owner, address _operator)
+        external
+        view
+        returns (bool);
+}
--- a/contracts/zero-ex/contracts/src/vendor/IFeeRecipient.sol
+++ b/contracts/zero-ex/contracts/src/vendor/IFeeRecipient.sol
@@ -0,0 +1,44 @@
+// SPDX-License-Identifier: Apache-2.0
+/*
+
+  Copyright 2021 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 ^0.6;
+pragma experimental ABIEncoderV2;
+
+
+interface IFeeRecipient {
+
+    /// @dev A callback function invoked in the ERC721Feature for each ERC721
+    ///      order fee that get paid. Integrators can make use of this callback
+    ///      to implement arbitrary fee-handling logic, e.g. splitting the fee
+    ///      between multiple parties.
+    /// @param tokenAddress The address of the token in which the received fee is
+    ///        denominated. `0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE` indicates
+    ///        that the fee was paid in the native token (e.g. ETH).
+    /// @param amount The amount of the given token received.
+    /// @param feeData Arbitrary data encoded in the `Fee` used by this callback.
+    /// @return success The selector of this function (0x0190805e),
+    ///         indicating that the callback succeeded.
+    function receiveZeroExFeeCallback(
+        address tokenAddress,
+        uint256 amount,
+        bytes calldata feeData
+    )
+        external
+        returns (bytes4 success);
+}
--- a/contracts/zero-ex/contracts/src/vendor/IPropertyValidator.sol
+++ b/contracts/zero-ex/contracts/src/vendor/IPropertyValidator.sol
@@ -18,28 +18,21 @@
 */

 pragma solidity ^0.6;
+pragma experimental ABIEncoderV2;


-interface ISmoothy {
+interface IPropertyValidator {

-    function getBalance (
-        uint256 tid
+    /// @dev Checks that the given ERC721/ERC1155 asset satisfies the properties encoded in `propertyData`.
+    ///      Should revert if the asset does not satisfy the specified properties.
+    /// @param tokenAddress The ERC721/ERC1155 token contract address.
+    /// @param tokenId The ERC721/ERC1155 tokenId of the asset to check.
+    /// @param propertyData Encoded properties or auxiliary data needed to perform the check.
+    function validateProperty(
+        address tokenAddress,
+        uint256 tokenId,
+        bytes calldata propertyData
    )
        external
-        view
-        returns (uint256 balance);
-
-    function _yBalances (
-        uint256 tid
-    )
-        external
-        view
-        returns (uint256 balance);
-
-    function getTokenStats (
-        uint256 tid
-    )
-        external
-        view
-        returns (uint256 softWeight, uint256 hardWeight, uint256 balance, uint256 decimals);
+        view;
 }
--- a/contracts/zero-ex/contracts/src/vendor/ITakerCallback.sol
+++ b/contracts/zero-ex/contracts/src/vendor/ITakerCallback.sol
@@ -0,0 +1,40 @@
+// SPDX-License-Identifier: Apache-2.0
+/*
+
+  Copyright 2021 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 ^0.6;
+pragma experimental ABIEncoderV2;
+
+
+interface ITakerCallback {
+
+    /// @dev A taker callback function invoked in ERC721OrdersFeature and
+    ///      ERC1155OrdersFeature between the maker -> taker transfer and
+    ///      the taker -> maker transfer.
+    /// @param orderHash The hash of the order being filled when this
+    ///        callback is invoked.
+    /// @param callbackData Arbitrary data used by this callback.
+    /// @return success The selector of this function,
+    ///         indicating that the callback succeeded.
+    function zeroExTakerCallback(
+        bytes32 orderHash,
+        bytes calldata callbackData
+    )
+        external
+        returns (bytes4 success);
+}
--- a/contracts/zero-ex/contracts/test/TestFeeRecipient.sol
+++ b/contracts/zero-ex/contracts/test/TestFeeRecipient.sol
@@ -0,0 +1,55 @@
+// SPDX-License-Identifier: Apache-2.0
+/*
+
+  Copyright 2021 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 ^0.6.5;
+pragma experimental ABIEncoderV2;
+
+
+contract TestFeeRecipient {
+    bytes4 constant private SUCCESS = this.receiveZeroExFeeCallback.selector;
+    bytes4 constant private FAILURE = 0xdeadbeef;
+
+    uint256 constant private TRIGGER_REVERT = 333;
+    uint256 constant private TRIGGER_FAILURE = 666;
+
+    event FeeReceived(
+        address tokenAddress,
+        uint256 amount
+    );
+
+    receive() external payable {}
+
+    function receiveZeroExFeeCallback(
+        address tokenAddress,
+        uint256 amount,
+        bytes calldata /* feeData */
+    )
+        external
+        returns (bytes4 success)
+    {
+        emit FeeReceived(tokenAddress, amount);
+        if (amount == TRIGGER_REVERT) {
+            revert("TestFeeRecipient::receiveZeroExFeeCallback/REVERT");
+        } else if (amount == TRIGGER_FAILURE) {
+            return FAILURE;
+        } else {
+            return SUCCESS;
+        }
+    }
+}
--- a/contracts/zero-ex/contracts/test/TestFillQuoteTransformerBridge.sol
+++ b/contracts/zero-ex/contracts/test/TestFillQuoteTransformerBridge.sol
@@ -22,7 +22,7 @@ pragma experimental ABIEncoderV2;

 import "@0x/contracts-utils/contracts/src/v06/LibMathV06.sol";
 import "../src/vendor/v3/IERC20Bridge.sol";
-import "./TestMintableERC20Token.sol";
+import "./tokens/TestMintableERC20Token.sol";


 contract TestFillQuoteTransformerBridge {
--- a/contracts/zero-ex/contracts/test/TestFillQuoteTransformerExchange.sol
+++ b/contracts/zero-ex/contracts/test/TestFillQuoteTransformerExchange.sol
@@ -23,7 +23,7 @@ pragma experimental ABIEncoderV2;
 import "@0x/contracts-utils/contracts/src/v06/LibBytesV06.sol";
 import "@0x/contracts-utils/contracts/src/v06/LibMathV06.sol";
 import "@0x/contracts-utils/contracts/src/v06/LibSafeMathV06.sol";
-import "./TestMintableERC20Token.sol";
+import "./tokens/TestMintableERC20Token.sol";
 import "../src/features/libs/LibNativeOrder.sol";
 import "../src/features/libs/LibSignature.sol";

--- a/contracts/zero-ex/contracts/test/TestFillQuoteTransformerHost.sol
+++ b/contracts/zero-ex/contracts/test/TestFillQuoteTransformerHost.sol
@@ -21,7 +21,7 @@ pragma solidity ^0.6.5;
 pragma experimental ABIEncoderV2;

 import "../src/transformers/IERC20Transformer.sol";
-import "./TestMintableERC20Token.sol";
+import "./tokens/TestMintableERC20Token.sol";
 import "./TestTransformerHost.sol";


--- a/contracts/zero-ex/contracts/test/TestMintTokenERC20Transformer.sol
+++ b/contracts/zero-ex/contracts/test/TestMintTokenERC20Transformer.sol
@@ -23,7 +23,7 @@ pragma experimental ABIEncoderV2;
 import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
 import "../src/transformers/IERC20Transformer.sol";
 import "../src/transformers/LibERC20Transformer.sol";
-import "./TestMintableERC20Token.sol";
+import "./tokens/TestMintableERC20Token.sol";


 contract TestMintTokenERC20Transformer is
--- a/contracts/zero-ex/contracts/test/TestNFTOrderPresigner.sol
+++ b/contracts/zero-ex/contracts/test/TestNFTOrderPresigner.sol
@@ -0,0 +1,93 @@
+// SPDX-License-Identifier: Apache-2.0
+/*
+
+  Copyright 2021 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 ^0.6.5;
+pragma experimental ABIEncoderV2;
+
+import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
+import "../src/IZeroEx.sol";
+import "../src/vendor/IERC1155Token.sol";
+import "../src/vendor/IERC721Token.sol";
+import "../src/features/libs/LibNFTOrder.sol";
+
+
+contract TestNFTOrderPresigner {
+    IZeroEx private immutable zeroEx;
+
+    constructor(IZeroEx _zeroEx)
+        public
+    {
+        zeroEx = _zeroEx;
+    }
+
+    function onERC1155Received(
+        address operator,
+        address from,
+        uint256 id,
+        uint256 value,
+        bytes calldata data
+    )
+        external
+        returns(bytes4 success)
+    {
+        return 0xf23a6e61;
+    }
+
+    function approveERC721(IERC721Token token)
+        external
+    {
+        token.setApprovalForAll(address(zeroEx), true);
+    }
+
+    function approveERC1155(IERC1155Token token)
+        external
+    {
+        token.setApprovalForAll(address(zeroEx), true);
+    }
+
+    function approveERC20(IERC20TokenV06 token)
+        external
+    {
+        token.approve(address(zeroEx), uint256(-1));
+    }
+
+    function preSignERC721Order(LibNFTOrder.ERC721Order calldata order)
+        external
+    {
+        zeroEx.preSignERC721Order(order);
+    }
+
+    function preSignERC1155Order(LibNFTOrder.ERC1155Order calldata order)
+        external
+    {
+        zeroEx.preSignERC1155Order(order);
+    }
+
+    function cancelERC721Order(uint256 orderNonce)
+        external
+    {
+        zeroEx.cancelERC721Order(orderNonce);
+    }
+
+    function cancelERC1155Order(uint256 orderNonce)
+        external
+    {
+        zeroEx.cancelERC1155Order(orderNonce);
+    }
+}
--- a/packages/asset-swapper/contracts/src/interfaces/IMooniswap.sol
+++ b/packages/asset-swapper/contracts/src/interfaces/IMooniswap.sol
@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: Apache-2.0
 /*

-  Copyright 2020 ZeroEx Intl.
+  Copyright 2021 ZeroEx Intl.

  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
@@ -17,22 +17,23 @@

 */

-pragma solidity ^0.6;
+pragma solidity ^0.6.5;
+pragma experimental ABIEncoderV2;


-interface IMooniswapRegistry {
+contract TestPropertyValidator {

-    function pools(address token1, address token2) external view returns(address);
-}
-
-interface IMooniswap {
-
-    function getReturn(
-        address fromToken,
-        address destToken,
-        uint256 amount
+    function validateProperty(
+        address tokenAddress,
+        uint256 tokenId,
+        bytes calldata propertyData
    )
        external
        view
-        returns(uint256 returnAmount);
+    {
+        require(
+            propertyData.length > 0,
+            "TestPropertyValidator::validateProperty/REVERT"
+        );
+    }
 }
--- a/contracts/zero-ex/contracts/test/TestWethTransformerHost.sol
+++ b/contracts/zero-ex/contracts/test/TestWethTransformerHost.sol
@@ -21,9 +21,9 @@ pragma solidity ^0.6.5;
 pragma experimental ABIEncoderV2;

 import "../src/transformers/IERC20Transformer.sol";
-import "./TestMintableERC20Token.sol";
+import "./tokens/TestMintableERC20Token.sol";
 import "./TestTransformerHost.sol";
-import "./TestWeth.sol";
+import "./tokens/TestWeth.sol";


 contract TestWethTransformerHost is
--- a/contracts/zero-ex/contracts/test/integration/TestCurve.sol
+++ b/contracts/zero-ex/contracts/test/integration/TestCurve.sol
@@ -21,7 +21,7 @@ pragma solidity ^0.6.5;
 pragma experimental ABIEncoderV2;

 import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
-import "./TestMintableERC20Token.sol";
+import "../tokens/TestMintableERC20Token.sol";

 contract TestCurve {

--- a/contracts/zero-ex/contracts/test/integration/TestLiquidityProvider.sol
+++ b/contracts/zero-ex/contracts/test/integration/TestLiquidityProvider.sol
--- a/contracts/zero-ex/contracts/test/integration/TestMooniswap.sol
+++ b/contracts/zero-ex/contracts/test/integration/TestMooniswap.sol
@@ -21,7 +21,7 @@ pragma solidity ^0.6.5;
 pragma experimental ABIEncoderV2;

 import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
-import "./TestMintableERC20Token.sol";
+import "../tokens/TestMintableERC20Token.sol";

 contract TestMooniswap {

--- a/contracts/zero-ex/contracts/test/integration/TestUniswapV2Factory.sol
+++ b/contracts/zero-ex/contracts/test/integration/TestUniswapV2Factory.sol
--- a/contracts/zero-ex/contracts/test/integration/TestUniswapV2Pool.sol
+++ b/contracts/zero-ex/contracts/test/integration/TestUniswapV2Pool.sol
@@ -2,7 +2,7 @@
 pragma solidity ^0.6;
 pragma experimental ABIEncoderV2;
 import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
-import "../src/vendor/IUniswapV2Pair.sol";
+import "../../src/vendor/IUniswapV2Pair.sol";

 interface IUniswapV2PoolDeployer {
    struct CreationParameters {
--- a/contracts/zero-ex/contracts/test/integration/TestUniswapV3Factory.sol
+++ b/contracts/zero-ex/contracts/test/integration/TestUniswapV3Factory.sol
--- a/contracts/zero-ex/contracts/test/integration/TestUniswapV3Pool.sol
+++ b/contracts/zero-ex/contracts/test/integration/TestUniswapV3Pool.sol
@@ -2,7 +2,7 @@
 pragma solidity ^0.6;
 pragma experimental ABIEncoderV2;
 import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
-import "../src/vendor/IUniswapV3Pool.sol";
+import "../../src/vendor/IUniswapV3Pool.sol";

 interface IUniswapV3PoolDeployer {
    struct CreationParameters {
--- a/contracts/zero-ex/contracts/test/tokens/TestMintableERC1155Token.sol
+++ b/contracts/zero-ex/contracts/test/tokens/TestMintableERC1155Token.sol
@@ -0,0 +1,345 @@
+// SPDX-License-Identifier: Apache-2.0
+/*
+
+  Copyright 2019 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 ^0.6;
+pragma experimental ABIEncoderV2;
+
+import "@0x/contracts-utils/contracts/src/v06/LibSafeMathV06.sol";
+
+
+interface IERC1155Receiver {
+
+    /// @notice Handle the receipt of a single ERC1155 token type
+    /// @dev The smart contract calls this function on the recipient
+    /// after a `safeTransferFrom`. This function MAY throw to revert and reject the
+    /// transfer. Return of other than the magic value MUST result in the
+    ///transaction being reverted
+    /// Note: the contract address is always the message sender
+    /// @param operator  The address which called `safeTransferFrom` function
+    /// @param from      The address which previously owned the token
+    /// @param id        An array containing the ids of the token being transferred
+    /// @param value     An array containing the amount of tokens being transferred
+    /// @param data      Additional data with no specified format
+    /// @return success  `bytes4(keccak256("onERC1155Received(address,address,uint256,uint256,bytes)"))`
+    function onERC1155Received(
+        address operator,
+        address from,
+        uint256 id,
+        uint256 value,
+        bytes calldata data
+    )
+        external
+        returns(bytes4 success);
+
+    /// @notice Handle the receipt of multiple ERC1155 token types
+    /// @dev The smart contract calls this function on the recipient
+    /// after a `safeTransferFrom`. This function MAY throw to revert and reject the
+    /// transfer. Return of other than the magic value MUST result in the
+    /// transaction being reverted
+    /// Note: the contract address is always the message sender
+    /// @param operator  The address which called `safeTransferFrom` function
+    /// @param from      The address which previously owned the token
+    /// @param ids       An array containing ids of each token being transferred
+    /// @param values    An array containing amounts of each token being transferred
+    /// @param data      Additional data with no specified format
+    /// @return success  `bytes4(keccak256("onERC1155Received(address,address,uint256,uint256,bytes)"))`
+    function onERC1155BatchReceived(
+        address operator,
+        address from,
+        uint256[] calldata ids,
+        uint256[] calldata values,
+        bytes calldata data
+    )
+        external
+        returns(bytes4 success);
+}
+
+contract TestMintableERC1155Token {
+    using LibSafeMathV06 for uint256;
+
+    /// @dev Either TransferSingle or TransferBatch MUST emit when tokens are transferred,
+    ///      including zero value transfers as well as minting or burning.
+    /// Operator will always be msg.sender.
+    /// Either event from address `0x0` signifies a minting operation.
+    /// An event to address `0x0` signifies a burning or melting operation.
+    /// The total value transferred from address 0x0 minus the total value transferred to 0x0 may
+    /// be used by clients and exchanges to be added to the "circulating supply" for a given token ID.
+    /// To define a token ID with no initial balance, the contract SHOULD emit the TransferSingle event
+    /// from `0x0` to `0x0`, with the token creator as `_operator`.
+    event TransferSingle(
+        address indexed operator,
+        address indexed from,
+        address indexed to,
+        uint256 id,
+        uint256 value
+    );
+
+    /// @dev Either TransferSingle or TransferBatch MUST emit when tokens are transferred,
+    ///      including zero value transfers as well as minting or burning.
+    ///Operator will always be msg.sender.
+    /// Either event from address `0x0` signifies a minting operation.
+    /// An event to address `0x0` signifies a burning or melting operation.
+    /// The total value transferred from address 0x0 minus the total value transferred to 0x0 may
+    /// be used by clients and exchanges to be added to the "circulating supply" for a given token ID.
+    /// To define multiple token IDs with no initial balance, this SHOULD emit the TransferBatch event
+    /// from `0x0` to `0x0`, with the token creator as `_operator`.
+    event TransferBatch(
+        address indexed operator,
+        address indexed from,
+        address indexed to,
+        uint256[] ids,
+        uint256[] values
+    );
+
+    /// @dev MUST emit when an approval is updated.
+    event ApprovalForAll(
+        address indexed owner,
+        address indexed operator,
+        bool approved
+    );
+
+    // selectors for receiver callbacks
+    bytes4 constant public ERC1155_RECEIVED       = 0xf23a6e61;
+    bytes4 constant public ERC1155_BATCH_RECEIVED = 0xbc197c81;
+
+    // id => (owner => balance)
+    mapping (uint256 => mapping(address => uint256)) internal balances;
+
+    // owner => (operator => approved)
+    mapping (address => mapping(address => bool)) internal operatorApproval;
+
+
+    function mint(
+        address to,
+        uint256 id,
+        uint256 quantity
+    )
+        external
+    {
+        // Grant the items to the caller
+        balances[id][to] = quantity.safeAdd(balances[id][to]);
+
+        // Emit the Transfer/Mint event.
+        // the 0x0 source address implies a mint
+        // It will also provide the circulating supply info.
+        emit TransferSingle(
+            msg.sender,
+            address(0x0),
+            to,
+            id,
+            quantity
+        );
+
+        // if `to` is a contract then trigger its callback
+        uint256 receiverCodeSize;
+        assembly {
+            receiverCodeSize := extcodesize(to)
+        }
+        if (receiverCodeSize > 0) {
+            bytes4 callbackReturnValue = IERC1155Receiver(to).onERC1155Received(
+                msg.sender,
+                msg.sender,
+                id,
+                quantity,
+                ""
+            );
+            require(
+                callbackReturnValue == ERC1155_RECEIVED,
+                "BAD_RECEIVER_RETURN_VALUE"
+            );
+        }
+    }
+
+    /// @notice Transfers value amount of an _id from the _from address to the _to address specified.
+    /// @dev MUST emit TransferSingle event on success.
+    /// Caller must be approved to manage the _from account's tokens (see isApprovedForAll).
+    /// MUST throw if `_to` is the zero address.
+    /// MUST throw if balance of sender for token `_id` is lower than the `_value` sent.
+    /// MUST throw on any other error.
+    /// When transfer is complete, this function MUST check if `_to` is a smart contract (code size > 0).
+    /// If so, it MUST call `onERC1155Received` on `_to` and revert if the return value
+    /// is not `bytes4(keccak256("onERC1155Received(address,address,uint256,uint256,bytes)"))`.
+    /// @param from    Source address
+    /// @param to      Target address
+    /// @param id      ID of the token type
+    /// @param value   Transfer amount
+    /// @param data    Additional data with no specified format, sent in call to `_to`
+    function safeTransferFrom(
+        address from,
+        address to,
+        uint256 id,
+        uint256 value,
+        bytes calldata data
+    )
+        external
+    {
+        // sanity checks
+        require(
+            to != address(0x0),
+            "CANNOT_TRANSFER_TO_ADDRESS_ZERO"
+        );
+        require(
+            from == msg.sender || operatorApproval[from][msg.sender] == true,
+            "INSUFFICIENT_ALLOWANCE"
+        );
+
+        // perform transfer
+        balances[id][from] = balances[id][from].safeSub(value);
+        balances[id][to] = balances[id][to].safeAdd(value);
+
+        emit TransferSingle(msg.sender, from, to, id, value);
+
+        // if `to` is a contract then trigger its callback
+        uint256 receiverCodeSize;
+        assembly {
+            receiverCodeSize := extcodesize(to)
+        }
+        if (receiverCodeSize > 0) {
+            bytes4 callbackReturnValue = IERC1155Receiver(to).onERC1155Received(
+                msg.sender,
+                from,
+                id,
+                value,
+                data
+            );
+            require(
+                callbackReturnValue == ERC1155_RECEIVED,
+                "BAD_RECEIVER_RETURN_VALUE"
+            );
+        }
+    }
+
+    /// @notice Send multiple types of Tokens from a 3rd party in one transfer (with safety call).
+    /// @dev MUST emit TransferBatch event on success.
+    /// Caller must be approved to manage the _from account's tokens (see isApprovedForAll).
+    /// MUST throw if `_to` is the zero address.
+    /// MUST throw if length of `_ids` is not the same as length of `_values`.
+    ///  MUST throw if any of the balance of sender for token `_ids` is lower than the respective `_values` sent.
+    /// MUST throw on any other error.
+    /// When transfer is complete, this function MUST check if `_to` is a smart contract (code size > 0).
+    /// If so, it MUST call `onERC1155BatchReceived` on `_to` and revert if the return value
+    /// is not `bytes4(keccak256("onERC1155BatchReceived(address,address,uint256[],uint256[],bytes)"))`.
+    /// @param from    Source addresses
+    /// @param to      Target addresses
+    /// @param ids     IDs of each token type
+    /// @param values  Transfer amounts per token type
+    /// @param data    Additional data with no specified format, sent in call to `_to`
+    function safeBatchTransferFrom(
+        address from,
+        address to,
+        uint256[] calldata ids,
+        uint256[] calldata values,
+        bytes calldata data
+    )
+        external
+    {
+        // sanity checks
+        require(
+            to != address(0x0),
+            "CANNOT_TRANSFER_TO_ADDRESS_ZERO"
+        );
+        require(
+            ids.length == values.length,
+            "TOKEN_AND_VALUES_LENGTH_MISMATCH"
+        );
+
+        // Only supporting a global operator approval allows us to do
+        // only 1 check and not to touch storage to handle allowances.
+        require(
+            from == msg.sender || operatorApproval[from][msg.sender] == true,
+            "INSUFFICIENT_ALLOWANCE"
+        );
+
+        // perform transfers
+        for (uint256 i = 0; i < ids.length; ++i) {
+            // Cache value to local variable to reduce read costs.
+            uint256 id = ids[i];
+            uint256 value = values[i];
+
+            balances[id][from] = balances[id][from].safeSub(value);
+            balances[id][to] = balances[id][to].safeAdd(value);
+        }
+        emit TransferBatch(msg.sender, from, to, ids, values);
+
+        // if `to` is a contract then trigger its callback
+        uint256 receiverCodeSize;
+        assembly {
+            receiverCodeSize := extcodesize(to)
+        }
+        if (receiverCodeSize > 0) {
+            bytes4 callbackReturnValue = IERC1155Receiver(to).onERC1155BatchReceived(
+                msg.sender,
+                from,
+                ids,
+                values,
+                data
+            );
+            require(
+                callbackReturnValue == ERC1155_BATCH_RECEIVED,
+                "BAD_RECEIVER_RETURN_VALUE"
+            );
+        }
+    }
+
+    /// @notice Enable or disable approval for a third party ("operator") to manage all of the caller's tokens.
+    /// @dev MUST emit the ApprovalForAll event on success.
+    /// @param operator  Address to add to the set of authorized operators
+    /// @param approved  True if the operator is approved, false to revoke approval
+    function setApprovalForAll(address operator, bool approved) external {
+        operatorApproval[msg.sender][operator] = approved;
+        emit ApprovalForAll(msg.sender, operator, approved);
+    }
+
+    /// @notice Queries the approval status of an operator for a given owner.
+    /// @param owner        The owner of the Tokens
+    /// @param operator     Address of authorized operator
+    /// @return isApproved  True if the operator is approved, false if not
+    function isApprovedForAll(address owner, address operator) external view returns (bool isApproved) {
+        return operatorApproval[owner][operator];
+    }
+
+    /// @notice Get the balance of an account's Tokens.
+    /// @param owner     The address of the token holder
+    /// @param id        ID of the Token
+    /// @return balance  The _owner's balance of the Token type requested
+    function balanceOf(address owner, uint256 id) external view returns (uint256 balance) {
+        return balances[id][owner];
+    }
+
+    /// @notice Get the balance of multiple account/token pairs
+    /// @param owners      The addresses of the token holders
+    /// @param ids         ID of the Tokens
+    /// @return balances_  The _owner's balance of the Token types requested
+    function balanceOfBatch(address[] calldata owners, uint256[] calldata ids) external view returns (uint256[] memory balances_) {
+        // sanity check
+        require(
+            owners.length == ids.length,
+            "OWNERS_AND_IDS_MUST_HAVE_SAME_LENGTH"
+        );
+
+        // get balances
+        balances_ = new uint256[](owners.length);
+        for (uint256 i = 0; i < owners.length; ++i) {
+            uint256 id = ids[i];
+            balances_[i] = balances[id][owners[i]];
+        }
+
+        return balances_;
+    }
+}
--- a/contracts/zero-ex/contracts/test/tokens/TestMintableERC20Token.sol
+++ b/contracts/zero-ex/contracts/test/tokens/TestMintableERC20Token.sol
--- a/contracts/zero-ex/contracts/test/tokens/TestMintableERC721Token.sol
+++ b/contracts/zero-ex/contracts/test/tokens/TestMintableERC721Token.sol
@@ -0,0 +1,385 @@
+// SPDX-License-Identifier: Apache-2.0
+/*
+
+  Copyright 2020 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 ^0.6.5;
+pragma experimental ABIEncoderV2;
+
+import "@0x/contracts-utils/contracts/src/v06/LibSafeMathV06.sol";
+
+
+interface IERC721Receiver {
+
+    /// @notice Handle the receipt of an NFT
+    /// @dev The ERC721 smart contract calls this function on the recipient
+    ///  after a `transfer`. This function MAY throw to revert and reject the
+    ///  transfer. Return of other than the magic value MUST result in the
+    ///  transaction being reverted.
+    ///  Note: the contract address is always the message sender.
+    /// @param _operator The address which called `safeTransferFrom` function
+    /// @param _from The address which previously owned the token
+    /// @param _tokenId The NFT identifier which is being transferred
+    /// @param _data Additional data with no specified format
+    /// @return `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`
+    ///  unless throwing
+    function onERC721Received(
+        address _operator,
+        address _from,
+        uint256 _tokenId,
+        bytes calldata _data
+    )
+        external
+        returns (bytes4);
+}
+
+contract TestMintableERC721Token {
+    using LibSafeMathV06 for uint256;
+
+    /// @dev This emits when ownership of any NFT changes by any mechanism.
+    ///      This event emits when NFTs are created (`from` == 0) and destroyed
+    ///      (`to` == 0). Exception: during contract creation, any number of NFTs
+    ///      may be created and assigned without emitting Transfer. At the time of
+    ///      any transfer, the approved address for that NFT (if any) is reset to none.
+    event Transfer(
+        address _from,
+        address _to,
+        uint256 _tokenId
+    );
+
+    /// @dev This emits when the approved address for an NFT is changed or
+    ///      reaffirmed. The zero address indicates there is no approved address.
+    ///      When a Transfer event emits, this also indicates that the approved
+    ///      address for that NFT (if any) is reset to none.
+    event Approval(
+        address indexed _owner,
+        address indexed _approved,
+        uint256 indexed _tokenId
+    );
+
+    /// @dev This emits when an operator is enabled or disabled for an owner.
+    ///      The operator can manage all NFTs of the owner.
+    event ApprovalForAll(
+        address indexed _owner,
+        address indexed _operator,
+        bool _approved
+    );
+
+    // Function selector for ERC721Receiver.onERC721Received
+    // 0x150b7a02
+    bytes4 constant private ERC721_RECEIVED = bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"));
+
+    // Mapping of tokenId => owner
+    mapping (uint256 => address) private owners;
+
+    // Mapping of tokenId => approved address
+    mapping (uint256 => address) private approvals;
+
+    // Mapping of owner => number of tokens owned
+    mapping (address => uint256) private balances;
+
+    // Mapping of owner => operator => approved
+    mapping (address => mapping (address => bool)) private operatorApprovals;
+
+    /// @dev Function to mint a new token
+    ///      Reverts if the given token ID already exists
+    /// @param _to Address of the beneficiary that will own the minted token
+    /// @param _tokenId ID of the token to be minted by the msg.sender    
+    function mint(address _to, uint256 _tokenId)
+        external
+    {
+        require(
+            _to != address(0),
+            "ERC721_ZERO_TO_ADDRESS"
+        );
+
+        address owner = owners[_tokenId];
+        require(
+            owner == address(0),
+            "ERC721_OWNER_ALREADY_EXISTS"
+        );
+
+        owners[_tokenId] = _to;
+        balances[_to] = balances[_to].safeAdd(1);
+
+        emit Transfer(
+            address(0),
+            _to,
+            _tokenId
+        );
+    }
+
+    /// @dev Function to burn a token
+    ///      Reverts if the given token ID doesn't exist
+    /// @param _owner Owner of token with given token ID
+    /// @param _tokenId ID of the token to be burned by the msg.sender
+    function burn(address _owner, uint256 _tokenId)
+        external
+    {
+        require(
+            _owner != address(0),
+            "ERC721_ZERO_OWNER_ADDRESS"
+        );
+
+        address owner = owners[_tokenId];
+        require(
+            owner == _owner,
+            "ERC721_OWNER_MISMATCH"
+        );
+
+        owners[_tokenId] = address(0);
+        balances[_owner] = balances[_owner].safeSub(1);
+
+        emit Transfer(
+            _owner,
+            address(0),
+            _tokenId
+        );
+    }
+
+    /// @notice Transfers the ownership of an NFT from one address to another address
+    /// @dev Throws unless `msg.sender` is the current owner, an authorized
+    ///      operator, or the approved address for this NFT. Throws if `_from` is
+    ///      not the current owner. Throws if `_to` is the zero address. Throws if
+    ///      `_tokenId` is not a valid NFT. When transfer is complete, this function
+    ///      checks if `_to` is a smart contract (code size > 0). If so, it calls
+    ///      `onERC721Received` on `_to` and throws if the return value is not
+    ///      `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`.
+    /// @param _from The current owner of the NFT
+    /// @param _to The new owner
+    /// @param _tokenId The NFT to transfer
+    /// @param _data Additional data with no specified format, sent in call to `_to`
+    function safeTransferFrom(
+        address _from,
+        address _to,
+        uint256 _tokenId,
+        bytes calldata _data
+    )
+        external
+    {
+        transferFrom(
+            _from,
+            _to,
+            _tokenId
+        );
+
+        uint256 receiverCodeSize;
+        assembly {
+            receiverCodeSize := extcodesize(_to)
+        }
+        if (receiverCodeSize > 0) {
+            bytes4 selector = IERC721Receiver(_to).onERC721Received(
+                msg.sender,
+                _from,
+                _tokenId,
+                _data
+            );
+            require(
+                selector == ERC721_RECEIVED,
+                "ERC721_INVALID_SELECTOR"
+            );
+        }
+    }
+
+    /// @notice Transfers the ownership of an NFT from one address to another address
+    /// @dev This works identically to the other function with an extra data parameter,
+    ///      except this function just sets data to "".
+    /// @param _from The current owner of the NFT
+    /// @param _to The new owner
+    /// @param _tokenId The NFT to transfer
+    function safeTransferFrom(
+        address _from,
+        address _to,
+        uint256 _tokenId
+    )
+        external
+    {
+        transferFrom(
+            _from,
+            _to,
+            _tokenId
+        );
+
+        uint256 receiverCodeSize;
+        assembly {
+            receiverCodeSize := extcodesize(_to)
+        }
+        if (receiverCodeSize > 0) {
+            bytes4 selector = IERC721Receiver(_to).onERC721Received(
+                msg.sender,
+                _from,
+                _tokenId,
+                ""
+            );
+            require(
+                selector == ERC721_RECEIVED,
+                "ERC721_INVALID_SELECTOR"
+            );
+        }
+    }
+
+    /// @notice Change or reaffirm the approved address for an NFT
+    /// @dev The zero address indicates there is no approved address.
+    ///      Throws unless `msg.sender` is the current NFT owner, or an authorized
+    ///      operator of the current owner.
+    /// @param _approved The new approved NFT controller
+    /// @param _tokenId The NFT to approve
+    function approve(address _approved, uint256 _tokenId)
+        external
+    {
+        address owner = ownerOf(_tokenId);
+        require(
+            msg.sender == owner || isApprovedForAll(owner, msg.sender),
+            "ERC721_INVALID_SENDER"
+        );
+
+        approvals[_tokenId] = _approved;
+        emit Approval(
+            owner,
+            _approved,
+            _tokenId
+        );
+    }
+
+    /// @notice Enable or disable approval for a third party ("operator") to manage
+    ///         all of `msg.sender`'s assets
+    /// @dev Emits the ApprovalForAll event. The contract MUST allow
+    ///      multiple operators per owner.
+    /// @param _operator Address to add to the set of authorized operators
+    /// @param _approved True if the operator is approved, false to revoke approval
+    function setApprovalForAll(address _operator, bool _approved)
+        external
+    {
+        operatorApprovals[msg.sender][_operator] = _approved;
+        emit ApprovalForAll(
+            msg.sender,
+            _operator,
+            _approved
+        );
+    }
+
+    /// @notice Count all NFTs assigned to an owner
+    /// @dev NFTs assigned to the zero address are considered invalid, and this
+    ///      function throws for queries about the zero address.
+    /// @param _owner An address for whom to query the balance
+    /// @return The number of NFTs owned by `_owner`, possibly zero
+    function balanceOf(address _owner)
+        external
+        view
+        returns (uint256)
+    {
+        require(
+            _owner != address(0),
+            "ERC721_ZERO_OWNER"
+        );
+        return balances[_owner];
+    }
+
+    /// @notice Transfer ownership of an NFT -- THE CALLER IS RESPONSIBLE
+    ///         TO CONFIRM THAT `_to` IS CAPABLE OF RECEIVING NFTS OR ELSE
+    ///         THEY MAY BE PERMANENTLY LOST
+    /// @dev Throws unless `msg.sender` is the current owner, an authorized
+    ///      operator, or the approved address for this NFT. Throws if `_from` is
+    ///      not the current owner. Throws if `_to` is the zero address. Throws if
+    ///      `_tokenId` is not a valid NFT.
+    /// @param _from The current owner of the NFT
+    /// @param _to The new owner
+    /// @param _tokenId The NFT to transfer
+    function transferFrom(
+        address _from,
+        address _to,
+        uint256 _tokenId
+    )
+        public
+    {
+        require(
+            _to != address(0),
+            "ERC721_ZERO_TO_ADDRESS"
+        );
+
+        address owner = ownerOf(_tokenId);
+        require(
+            _from == owner,
+            "ERC721_OWNER_MISMATCH"
+        );
+
+        address spender = msg.sender;
+        address approvedAddress = getApproved(_tokenId);
+        require(
+            spender == owner ||
+            isApprovedForAll(owner, spender) ||
+            approvedAddress == spender,
+            "ERC721_INVALID_SPENDER"
+        );
+
+        if (approvedAddress != address(0)) {
+            approvals[_tokenId] = address(0);
+        }
+
+        owners[_tokenId] = _to;
+        balances[_from] = balances[_from].safeSub(1);
+        balances[_to] = balances[_to].safeAdd(1);
+
+        emit Transfer(
+            _from,
+            _to,
+            _tokenId
+        );
+    }
+
+    /// @notice Find the owner of an NFT
+    /// @dev NFTs assigned to zero address are considered invalid, and queries
+    ///      about them do throw.
+    /// @param _tokenId The identifier for an NFT
+    /// @return The address of the owner of the NFT
+    function ownerOf(uint256 _tokenId)
+        public
+        view
+        returns (address)
+    {
+        address owner = owners[_tokenId];
+        require(
+            owner != address(0),
+            "ERC721_ZERO_OWNER"
+        );
+        return owner;
+    }
+
+    /// @notice Get the approved address for a single NFT
+    /// @dev Throws if `_tokenId` is not a valid NFT.
+    /// @param _tokenId The NFT to find the approved address for
+    /// @return The approved address for this NFT, or the zero address if there is none
+    function getApproved(uint256 _tokenId)
+        public
+        view
+        returns (address)
+    {
+        return approvals[_tokenId];
+    }
+
+    /// @notice Query if an address is an authorized operator for another address
+    /// @param _owner The address that owns the NFTs
+    /// @param _operator The address that acts on behalf of the owner
+    /// @return True if `_operator` is an approved operator for `_owner`, false otherwise
+    function isApprovedForAll(address _owner, address _operator)
+        public
+        view
+        returns (bool)
+    {
+        return operatorApprovals[_owner][_operator];
+    }
+}
--- a/contracts/zero-ex/contracts/test/tokens/TestTokenSpenderERC20Token.sol
+++ b/contracts/zero-ex/contracts/test/tokens/TestTokenSpenderERC20Token.sol
--- a/contracts/zero-ex/contracts/test/tokens/TestWeth.sol
+++ b/contracts/zero-ex/contracts/test/tokens/TestWeth.sol
--- a/contracts/zero-ex/package.json
+++ b/contracts/zero-ex/package.json
@@ -1,6 +1,6 @@
 {
    "name": "@0x/contracts-zero-ex",
-    "version": "0.30.1",
+    "version": "0.31.0",
    "engines": {
        "node": ">=6.12"
    },
@@ -43,7 +43,7 @@
    "config": {
        "publicInterfaceContracts": "IZeroEx,ZeroEx,FullMigration,InitialMigration,IFlashWallet,IERC20Transformer,IOwnableFeature,ISimpleFunctionRegistryFeature,ITransformERC20Feature,FillQuoteTransformer,PayTakerTransformer,PositiveSlippageFeeTransformer,WethTransformer,OwnableFeature,SimpleFunctionRegistryFeature,TransformERC20Feature,AffiliateFeeTransformer,MetaTransactionsFeature,LogMetadataTransformer,BridgeAdapter,LiquidityProviderFeature,ILiquidityProviderFeature,NativeOrdersFeature,INativeOrdersFeature,FeeCollectorController,FeeCollector,CurveLiquidityProvider,BatchFillNativeOrdersFeature,IBatchFillNativeOrdersFeature,MultiplexFeature,IMultiplexFeature,OtcOrdersFeature,IOtcOrdersFeature",
        "abis:comment": "This list is auto-generated by contracts-gen. Don't edit manually.",
-        "abis": "./test/generated-artifacts/@(AffiliateFeeTransformer|BatchFillNativeOrdersFeature|BootstrapFeature|BridgeAdapter|BridgeProtocols|CurveLiquidityProvider|FeeCollector|FeeCollectorController|FillQuoteTransformer|FixinCommon|FixinEIP712|FixinProtocolFees|FixinReentrancyGuard|FixinTokenSpender|FlashWallet|FullMigration|FundRecoveryFeature|IBatchFillNativeOrdersFeature|IBootstrapFeature|IBridgeAdapter|IERC20Bridge|IERC20Transformer|IFeature|IFlashWallet|IFundRecoveryFeature|ILiquidityProvider|ILiquidityProviderFeature|ILiquidityProviderSandbox|IMetaTransactionsFeature|IMooniswapPool|IMultiplexFeature|INativeOrdersEvents|INativeOrdersFeature|IOtcOrdersFeature|IOwnableFeature|IPancakeSwapFeature|ISimpleFunctionRegistryFeature|IStaking|ITestSimpleFunctionRegistryFeature|ITokenSpenderFeature|ITransformERC20Feature|IUniswapFeature|IUniswapV2Pair|IUniswapV3Feature|IUniswapV3Pool|IZeroEx|InitialMigration|LibBootstrap|LibCommonRichErrors|LibERC20Transformer|LibFeeCollector|LibLiquidityProviderRichErrors|LibMetaTransactionsRichErrors|LibMetaTransactionsStorage|LibMigrate|LibNativeOrder|LibNativeOrdersRichErrors|LibNativeOrdersStorage|LibOtcOrdersStorage|LibOwnableRichErrors|LibOwnableStorage|LibProxyRichErrors|LibProxyStorage|LibReentrancyGuardStorage|LibSignature|LibSignatureRichErrors|LibSimpleFunctionRegistryRichErrors|LibSimpleFunctionRegistryStorage|LibStorage|LibTransformERC20RichErrors|LibTransformERC20Storage|LibWalletRichErrors|LiquidityProviderFeature|LiquidityProviderSandbox|LogMetadataTransformer|MetaTransactionsFeature|MixinAaveV2|MixinBalancer|MixinBalancerV2|MixinBancor|MixinCoFiX|MixinCompound|MixinCryptoCom|MixinCurve|MixinCurveV2|MixinDodo|MixinDodoV2|MixinKyber|MixinKyberDmm|MixinLido|MixinMStable|MixinMakerPSM|MixinMooniswap|MixinNerve|MixinOasis|MixinShell|MixinUniswap|MixinUniswapV2|MixinUniswapV3|MixinZeroExBridge|MooniswapLiquidityProvider|MultiplexFeature|MultiplexLiquidityProvider|MultiplexOtc|MultiplexRfq|MultiplexTransformERC20|MultiplexUniswapV2|MultiplexUniswapV3|NativeOrdersCancellation|NativeOrdersFeature|NativeOrdersInfo|NativeOrdersProtocolFees|NativeOrdersSettlement|OtcOrdersFeature|OwnableFeature|PancakeSwapFeature|PayTakerTransformer|PermissionlessTransformerDeployer|PositiveSlippageFeeTransformer|SimpleFunctionRegistryFeature|TestBridge|TestCallTarget|TestCurve|TestDelegateCaller|TestFeeCollectorController|TestFillQuoteTransformerBridge|TestFillQuoteTransformerExchange|TestFillQuoteTransformerHost|TestFixinProtocolFees|TestFixinTokenSpender|TestFullMigration|TestInitialMigration|TestLibNativeOrder|TestLibSignature|TestLiquidityProvider|TestMetaTransactionsNativeOrdersFeature|TestMetaTransactionsTransformERC20Feature|TestMigrator|TestMintTokenERC20Transformer|TestMintableERC20Token|TestMooniswap|TestNativeOrdersFeature|TestNoEthRecipient|TestOrderSignerRegistryWithContractWallet|TestPermissionlessTransformerDeployerSuicidal|TestPermissionlessTransformerDeployerTransformer|TestRfqOriginRegistration|TestSimpleFunctionRegistryFeatureImpl1|TestSimpleFunctionRegistryFeatureImpl2|TestStaking|TestTokenSpenderERC20Token|TestTransformERC20|TestTransformerBase|TestTransformerDeployerTransformer|TestTransformerHost|TestUniswapV2Factory|TestUniswapV2Pool|TestUniswapV3Factory|TestUniswapV3Feature|TestUniswapV3Pool|TestWeth|TestWethTransformerHost|TestZeroExFeature|TransformERC20Feature|Transformer|TransformerDeployer|UniswapFeature|UniswapV3Feature|WethTransformer|ZeroEx|ZeroExOptimized).json"
+        "abis": "./test/generated-artifacts/@(AffiliateFeeTransformer|BatchFillNativeOrdersFeature|BootstrapFeature|BridgeAdapter|BridgeProtocols|CurveLiquidityProvider|ERC1155OrdersFeature|ERC165Feature|ERC721OrdersFeature|FeeCollector|FeeCollectorController|FillQuoteTransformer|FixinCommon|FixinEIP712|FixinERC1155Spender|FixinERC721Spender|FixinProtocolFees|FixinReentrancyGuard|FixinTokenSpender|FlashWallet|FullMigration|FundRecoveryFeature|IBatchFillNativeOrdersFeature|IBootstrapFeature|IBridgeAdapter|IERC1155OrdersFeature|IERC1155Token|IERC165Feature|IERC20Bridge|IERC20Transformer|IERC721OrdersFeature|IERC721Token|IFeature|IFeeRecipient|IFlashWallet|IFundRecoveryFeature|ILiquidityProvider|ILiquidityProviderFeature|ILiquidityProviderSandbox|IMetaTransactionsFeature|IMooniswapPool|IMultiplexFeature|INativeOrdersEvents|INativeOrdersFeature|IOtcOrdersFeature|IOwnableFeature|IPancakeSwapFeature|IPropertyValidator|ISimpleFunctionRegistryFeature|IStaking|ITakerCallback|ITestSimpleFunctionRegistryFeature|ITokenSpenderFeature|ITransformERC20Feature|IUniswapFeature|IUniswapV2Pair|IUniswapV3Feature|IUniswapV3Pool|IZeroEx|InitialMigration|LibBootstrap|LibCommonRichErrors|LibERC1155OrdersStorage|LibERC20Transformer|LibERC721OrdersStorage|LibFeeCollector|LibLiquidityProviderRichErrors|LibMetaTransactionsRichErrors|LibMetaTransactionsStorage|LibMigrate|LibNFTOrder|LibNFTOrdersRichErrors|LibNativeOrder|LibNativeOrdersRichErrors|LibNativeOrdersStorage|LibOtcOrdersStorage|LibOwnableRichErrors|LibOwnableStorage|LibProxyRichErrors|LibProxyStorage|LibReentrancyGuardStorage|LibSignature|LibSignatureRichErrors|LibSimpleFunctionRegistryRichErrors|LibSimpleFunctionRegistryStorage|LibStorage|LibTransformERC20RichErrors|LibTransformERC20Storage|LibWalletRichErrors|LiquidityProviderFeature|LiquidityProviderSandbox|LogMetadataTransformer|MetaTransactionsFeature|MixinAaveV2|MixinBalancer|MixinBalancerV2|MixinBancor|MixinCoFiX|MixinCompound|MixinCryptoCom|MixinCurve|MixinCurveV2|MixinDodo|MixinDodoV2|MixinKyber|MixinKyberDmm|MixinLido|MixinMStable|MixinMakerPSM|MixinMooniswap|MixinNerve|MixinOasis|MixinShell|MixinUniswap|MixinUniswapV2|MixinUniswapV3|MixinZeroExBridge|MooniswapLiquidityProvider|MultiplexFeature|MultiplexLiquidityProvider|MultiplexOtc|MultiplexRfq|MultiplexTransformERC20|MultiplexUniswapV2|MultiplexUniswapV3|NFTOrders|NativeOrdersCancellation|NativeOrdersFeature|NativeOrdersInfo|NativeOrdersProtocolFees|NativeOrdersSettlement|OtcOrdersFeature|OwnableFeature|PancakeSwapFeature|PayTakerTransformer|PermissionlessTransformerDeployer|PositiveSlippageFeeTransformer|SimpleFunctionRegistryFeature|TestBridge|TestCallTarget|TestCurve|TestDelegateCaller|TestFeeCollectorController|TestFeeRecipient|TestFillQuoteTransformerBridge|TestFillQuoteTransformerExchange|TestFillQuoteTransformerHost|TestFixinProtocolFees|TestFixinTokenSpender|TestFullMigration|TestInitialMigration|TestLibNativeOrder|TestLibSignature|TestLiquidityProvider|TestMetaTransactionsNativeOrdersFeature|TestMetaTransactionsTransformERC20Feature|TestMigrator|TestMintTokenERC20Transformer|TestMintableERC1155Token|TestMintableERC20Token|TestMintableERC721Token|TestMooniswap|TestNFTOrderPresigner|TestNativeOrdersFeature|TestNoEthRecipient|TestOrderSignerRegistryWithContractWallet|TestPermissionlessTransformerDeployerSuicidal|TestPermissionlessTransformerDeployerTransformer|TestPropertyValidator|TestRfqOriginRegistration|TestSimpleFunctionRegistryFeatureImpl1|TestSimpleFunctionRegistryFeatureImpl2|TestStaking|TestTokenSpenderERC20Token|TestTransformERC20|TestTransformerBase|TestTransformerDeployerTransformer|TestTransformerHost|TestUniswapV2Factory|TestUniswapV2Pool|TestUniswapV3Factory|TestUniswapV3Feature|TestUniswapV3Pool|TestWeth|TestWethTransformerHost|TestZeroExFeature|TransformERC20Feature|Transformer|TransformerDeployer|UniswapFeature|UniswapV3Feature|WethTransformer|ZeroEx|ZeroExOptimized).json"
    },
    "repository": {
        "type": "git",
@@ -55,14 +55,14 @@
    },
    "homepage": "https://github.com/0xProject/protocol/tree/main/contracts/zero-ex",
    "devDependencies": {
-        "@0x/abi-gen": "^5.6.2",
+        "@0x/abi-gen": "^5.7.3",
        "@0x/contract-addresses": "^6.11.0",
-        "@0x/contracts-erc20": "^3.3.25",
-        "@0x/contracts-gen": "^2.0.40",
-        "@0x/contracts-test-utils": "^5.4.16",
-        "@0x/dev-utils": "^4.2.9",
+        "@0x/contracts-erc20": "^3.3.26",
+        "@0x/contracts-gen": "^2.0.44",
+        "@0x/contracts-test-utils": "^5.4.17",
+        "@0x/dev-utils": "^4.2.12",
        "@0x/order-utils": "^10.4.28",
-        "@0x/sol-compiler": "^4.7.5",
+        "@0x/sol-compiler": "^4.7.9",
        "@0x/ts-doc-gen": "^0.0.28",
        "@0x/tslint-config": "^4.1.4",
        "@types/isomorphic-fetch": "^0.0.35",
@@ -82,14 +82,14 @@
        "typescript": "4.2.2"
    },
    "dependencies": {
-        "@0x/base-contract": "^6.4.2",
-        "@0x/protocol-utils": "^1.10.1",
-        "@0x/subproviders": "^6.6.0",
-        "@0x/types": "^3.3.4",
-        "@0x/typescript-typings": "^5.2.1",
-        "@0x/utils": "^6.4.4",
-        "@0x/web3-wrapper": "^7.6.0",
-        "ethereum-types": "^3.6.0",
+        "@0x/base-contract": "^6.4.6",
+        "@0x/protocol-utils": "^1.11.0",
+        "@0x/subproviders": "^6.6.3",
+        "@0x/types": "^3.3.5",
+        "@0x/typescript-typings": "^5.2.2",
+        "@0x/utils": "^6.5.1",
+        "@0x/web3-wrapper": "^7.6.3",
+        "ethereum-types": "^3.6.1",
        "ethereumjs-util": "^7.0.10",
        "ethers": "~4.0.4"
    },
--- a/contracts/zero-ex/test/artifacts.ts
+++ b/contracts/zero-ex/test/artifacts.ts
@@ -11,11 +11,16 @@ import * as BootstrapFeature from '../test/generated-artifacts/BootstrapFeature.
 import * as BridgeAdapter from '../test/generated-artifacts/BridgeAdapter.json';
 import * as BridgeProtocols from '../test/generated-artifacts/BridgeProtocols.json';
 import * as CurveLiquidityProvider from '../test/generated-artifacts/CurveLiquidityProvider.json';
+import * as ERC1155OrdersFeature from '../test/generated-artifacts/ERC1155OrdersFeature.json';
+import * as ERC165Feature from '../test/generated-artifacts/ERC165Feature.json';
+import * as ERC721OrdersFeature from '../test/generated-artifacts/ERC721OrdersFeature.json';
 import * as FeeCollector from '../test/generated-artifacts/FeeCollector.json';
 import * as FeeCollectorController from '../test/generated-artifacts/FeeCollectorController.json';
 import * as FillQuoteTransformer from '../test/generated-artifacts/FillQuoteTransformer.json';
 import * as FixinCommon from '../test/generated-artifacts/FixinCommon.json';
 import * as FixinEIP712 from '../test/generated-artifacts/FixinEIP712.json';
+import * as FixinERC1155Spender from '../test/generated-artifacts/FixinERC1155Spender.json';
+import * as FixinERC721Spender from '../test/generated-artifacts/FixinERC721Spender.json';
 import * as FixinProtocolFees from '../test/generated-artifacts/FixinProtocolFees.json';
 import * as FixinReentrancyGuard from '../test/generated-artifacts/FixinReentrancyGuard.json';
 import * as FixinTokenSpender from '../test/generated-artifacts/FixinTokenSpender.json';
@@ -25,9 +30,15 @@ import * as FundRecoveryFeature from '../test/generated-artifacts/FundRecoveryFe
 import * as IBatchFillNativeOrdersFeature from '../test/generated-artifacts/IBatchFillNativeOrdersFeature.json';
 import * as IBootstrapFeature from '../test/generated-artifacts/IBootstrapFeature.json';
 import * as IBridgeAdapter from '../test/generated-artifacts/IBridgeAdapter.json';
+import * as IERC1155OrdersFeature from '../test/generated-artifacts/IERC1155OrdersFeature.json';
+import * as IERC1155Token from '../test/generated-artifacts/IERC1155Token.json';
+import * as IERC165Feature from '../test/generated-artifacts/IERC165Feature.json';
 import * as IERC20Bridge from '../test/generated-artifacts/IERC20Bridge.json';
 import * as IERC20Transformer from '../test/generated-artifacts/IERC20Transformer.json';
+import * as IERC721OrdersFeature from '../test/generated-artifacts/IERC721OrdersFeature.json';
+import * as IERC721Token from '../test/generated-artifacts/IERC721Token.json';
 import * as IFeature from '../test/generated-artifacts/IFeature.json';
+import * as IFeeRecipient from '../test/generated-artifacts/IFeeRecipient.json';
 import * as IFlashWallet from '../test/generated-artifacts/IFlashWallet.json';
 import * as IFundRecoveryFeature from '../test/generated-artifacts/IFundRecoveryFeature.json';
 import * as ILiquidityProvider from '../test/generated-artifacts/ILiquidityProvider.json';
@@ -42,8 +53,10 @@ import * as InitialMigration from '../test/generated-artifacts/InitialMigration.
 import * as IOtcOrdersFeature from '../test/generated-artifacts/IOtcOrdersFeature.json';
 import * as IOwnableFeature from '../test/generated-artifacts/IOwnableFeature.json';
 import * as IPancakeSwapFeature from '../test/generated-artifacts/IPancakeSwapFeature.json';
+import * as IPropertyValidator from '../test/generated-artifacts/IPropertyValidator.json';
 import * as ISimpleFunctionRegistryFeature from '../test/generated-artifacts/ISimpleFunctionRegistryFeature.json';
 import * as IStaking from '../test/generated-artifacts/IStaking.json';
+import * as ITakerCallback from '../test/generated-artifacts/ITakerCallback.json';
 import * as ITestSimpleFunctionRegistryFeature from '../test/generated-artifacts/ITestSimpleFunctionRegistryFeature.json';
 import * as ITokenSpenderFeature from '../test/generated-artifacts/ITokenSpenderFeature.json';
 import * as ITransformERC20Feature from '../test/generated-artifacts/ITransformERC20Feature.json';
@@ -54,7 +67,9 @@ import * as IUniswapV3Pool from '../test/generated-artifacts/IUniswapV3Pool.json
 import * as IZeroEx from '../test/generated-artifacts/IZeroEx.json';
 import * as LibBootstrap from '../test/generated-artifacts/LibBootstrap.json';
 import * as LibCommonRichErrors from '../test/generated-artifacts/LibCommonRichErrors.json';
+import * as LibERC1155OrdersStorage from '../test/generated-artifacts/LibERC1155OrdersStorage.json';
 import * as LibERC20Transformer from '../test/generated-artifacts/LibERC20Transformer.json';
+import * as LibERC721OrdersStorage from '../test/generated-artifacts/LibERC721OrdersStorage.json';
 import * as LibFeeCollector from '../test/generated-artifacts/LibFeeCollector.json';
 import * as LibLiquidityProviderRichErrors from '../test/generated-artifacts/LibLiquidityProviderRichErrors.json';
 import * as LibMetaTransactionsRichErrors from '../test/generated-artifacts/LibMetaTransactionsRichErrors.json';
@@ -63,6 +78,8 @@ import * as LibMigrate from '../test/generated-artifacts/LibMigrate.json';
 import * as LibNativeOrder from '../test/generated-artifacts/LibNativeOrder.json';
 import * as LibNativeOrdersRichErrors from '../test/generated-artifacts/LibNativeOrdersRichErrors.json';
 import * as LibNativeOrdersStorage from '../test/generated-artifacts/LibNativeOrdersStorage.json';
+import * as LibNFTOrder from '../test/generated-artifacts/LibNFTOrder.json';
+import * as LibNFTOrdersRichErrors from '../test/generated-artifacts/LibNFTOrdersRichErrors.json';
 import * as LibOtcOrdersStorage from '../test/generated-artifacts/LibOtcOrdersStorage.json';
 import * as LibOwnableRichErrors from '../test/generated-artifacts/LibOwnableRichErrors.json';
 import * as LibOwnableStorage from '../test/generated-artifacts/LibOwnableStorage.json';
@@ -118,6 +135,7 @@ import * as NativeOrdersFeature from '../test/generated-artifacts/NativeOrdersFe
 import * as NativeOrdersInfo from '../test/generated-artifacts/NativeOrdersInfo.json';
 import * as NativeOrdersProtocolFees from '../test/generated-artifacts/NativeOrdersProtocolFees.json';
 import * as NativeOrdersSettlement from '../test/generated-artifacts/NativeOrdersSettlement.json';
+import * as NFTOrders from '../test/generated-artifacts/NFTOrders.json';
 import * as OtcOrdersFeature from '../test/generated-artifacts/OtcOrdersFeature.json';
 import * as OwnableFeature from '../test/generated-artifacts/OwnableFeature.json';
 import * as PancakeSwapFeature from '../test/generated-artifacts/PancakeSwapFeature.json';
@@ -130,6 +148,7 @@ import * as TestCallTarget from '../test/generated-artifacts/TestCallTarget.json
 import * as TestCurve from '../test/generated-artifacts/TestCurve.json';
 import * as TestDelegateCaller from '../test/generated-artifacts/TestDelegateCaller.json';
 import * as TestFeeCollectorController from '../test/generated-artifacts/TestFeeCollectorController.json';
+import * as TestFeeRecipient from '../test/generated-artifacts/TestFeeRecipient.json';
 import * as TestFillQuoteTransformerBridge from '../test/generated-artifacts/TestFillQuoteTransformerBridge.json';
 import * as TestFillQuoteTransformerExchange from '../test/generated-artifacts/TestFillQuoteTransformerExchange.json';
 import * as TestFillQuoteTransformerHost from '../test/generated-artifacts/TestFillQuoteTransformerHost.json';
@@ -143,14 +162,18 @@ import * as TestLiquidityProvider from '../test/generated-artifacts/TestLiquidit
 import * as TestMetaTransactionsNativeOrdersFeature from '../test/generated-artifacts/TestMetaTransactionsNativeOrdersFeature.json';
 import * as TestMetaTransactionsTransformERC20Feature from '../test/generated-artifacts/TestMetaTransactionsTransformERC20Feature.json';
 import * as TestMigrator from '../test/generated-artifacts/TestMigrator.json';
+import * as TestMintableERC1155Token from '../test/generated-artifacts/TestMintableERC1155Token.json';
 import * as TestMintableERC20Token from '../test/generated-artifacts/TestMintableERC20Token.json';
+import * as TestMintableERC721Token from '../test/generated-artifacts/TestMintableERC721Token.json';
 import * as TestMintTokenERC20Transformer from '../test/generated-artifacts/TestMintTokenERC20Transformer.json';
 import * as TestMooniswap from '../test/generated-artifacts/TestMooniswap.json';
 import * as TestNativeOrdersFeature from '../test/generated-artifacts/TestNativeOrdersFeature.json';
+import * as TestNFTOrderPresigner from '../test/generated-artifacts/TestNFTOrderPresigner.json';
 import * as TestNoEthRecipient from '../test/generated-artifacts/TestNoEthRecipient.json';
 import * as TestOrderSignerRegistryWithContractWallet from '../test/generated-artifacts/TestOrderSignerRegistryWithContractWallet.json';
 import * as TestPermissionlessTransformerDeployerSuicidal from '../test/generated-artifacts/TestPermissionlessTransformerDeployerSuicidal.json';
 import * as TestPermissionlessTransformerDeployerTransformer from '../test/generated-artifacts/TestPermissionlessTransformerDeployerTransformer.json';
+import * as TestPropertyValidator from '../test/generated-artifacts/TestPropertyValidator.json';
 import * as TestRfqOriginRegistration from '../test/generated-artifacts/TestRfqOriginRegistration.json';
 import * as TestSimpleFunctionRegistryFeatureImpl1 from '../test/generated-artifacts/TestSimpleFunctionRegistryFeatureImpl1.json';
 import * as TestSimpleFunctionRegistryFeatureImpl2 from '../test/generated-artifacts/TestSimpleFunctionRegistryFeatureImpl2.json';
@@ -183,6 +206,7 @@ export const artifacts = {
    LibCommonRichErrors: LibCommonRichErrors as ContractArtifact,
    LibLiquidityProviderRichErrors: LibLiquidityProviderRichErrors as ContractArtifact,
    LibMetaTransactionsRichErrors: LibMetaTransactionsRichErrors as ContractArtifact,
+    LibNFTOrdersRichErrors: LibNFTOrdersRichErrors as ContractArtifact,
    LibNativeOrdersRichErrors: LibNativeOrdersRichErrors as ContractArtifact,
    LibOwnableRichErrors: LibOwnableRichErrors as ContractArtifact,
    LibProxyRichErrors: LibProxyRichErrors as ContractArtifact,
@@ -201,6 +225,7 @@ export const artifacts = {
    TransformerDeployer: TransformerDeployer as ContractArtifact,
    BatchFillNativeOrdersFeature: BatchFillNativeOrdersFeature as ContractArtifact,
    BootstrapFeature: BootstrapFeature as ContractArtifact,
+    ERC165Feature: ERC165Feature as ContractArtifact,
    FundRecoveryFeature: FundRecoveryFeature as ContractArtifact,
    LiquidityProviderFeature: LiquidityProviderFeature as ContractArtifact,
    MetaTransactionsFeature: MetaTransactionsFeature as ContractArtifact,
@@ -214,6 +239,9 @@ export const artifacts = {
    UniswapV3Feature: UniswapV3Feature as ContractArtifact,
    IBatchFillNativeOrdersFeature: IBatchFillNativeOrdersFeature as ContractArtifact,
    IBootstrapFeature: IBootstrapFeature as ContractArtifact,
+    IERC1155OrdersFeature: IERC1155OrdersFeature as ContractArtifact,
+    IERC165Feature: IERC165Feature as ContractArtifact,
+    IERC721OrdersFeature: IERC721OrdersFeature as ContractArtifact,
    IFeature: IFeature as ContractArtifact,
    IFundRecoveryFeature: IFundRecoveryFeature as ContractArtifact,
    ILiquidityProviderFeature: ILiquidityProviderFeature as ContractArtifact,
@@ -229,6 +257,7 @@ export const artifacts = {
    ITransformERC20Feature: ITransformERC20Feature as ContractArtifact,
    IUniswapFeature: IUniswapFeature as ContractArtifact,
    IUniswapV3Feature: IUniswapV3Feature as ContractArtifact,
+    LibNFTOrder: LibNFTOrder as ContractArtifact,
    LibNativeOrder: LibNativeOrder as ContractArtifact,
    LibSignature: LibSignature as ContractArtifact,
    MultiplexFeature: MultiplexFeature as ContractArtifact,
@@ -242,8 +271,13 @@ export const artifacts = {
    NativeOrdersInfo: NativeOrdersInfo as ContractArtifact,
    NativeOrdersProtocolFees: NativeOrdersProtocolFees as ContractArtifact,
    NativeOrdersSettlement: NativeOrdersSettlement as ContractArtifact,
+    ERC1155OrdersFeature: ERC1155OrdersFeature as ContractArtifact,
+    ERC721OrdersFeature: ERC721OrdersFeature as ContractArtifact,
+    NFTOrders: NFTOrders as ContractArtifact,
    FixinCommon: FixinCommon as ContractArtifact,
    FixinEIP712: FixinEIP712 as ContractArtifact,
+    FixinERC1155Spender: FixinERC1155Spender as ContractArtifact,
+    FixinERC721Spender: FixinERC721Spender as ContractArtifact,
    FixinProtocolFees: FixinProtocolFees as ContractArtifact,
    FixinReentrancyGuard: FixinReentrancyGuard as ContractArtifact,
    FixinTokenSpender: FixinTokenSpender as ContractArtifact,
@@ -253,6 +287,8 @@ export const artifacts = {
    InitialMigration: InitialMigration as ContractArtifact,
    LibBootstrap: LibBootstrap as ContractArtifact,
    LibMigrate: LibMigrate as ContractArtifact,
+    LibERC1155OrdersStorage: LibERC1155OrdersStorage as ContractArtifact,
+    LibERC721OrdersStorage: LibERC721OrdersStorage as ContractArtifact,
    LibMetaTransactionsStorage: LibMetaTransactionsStorage as ContractArtifact,
    LibNativeOrdersStorage: LibNativeOrdersStorage as ContractArtifact,
    LibOtcOrdersStorage: LibOtcOrdersStorage as ContractArtifact,
@@ -298,8 +334,13 @@ export const artifacts = {
    MixinUniswapV2: MixinUniswapV2 as ContractArtifact,
    MixinUniswapV3: MixinUniswapV3 as ContractArtifact,
    MixinZeroExBridge: MixinZeroExBridge as ContractArtifact,
+    IERC1155Token: IERC1155Token as ContractArtifact,
+    IERC721Token: IERC721Token as ContractArtifact,
+    IFeeRecipient: IFeeRecipient as ContractArtifact,
    ILiquidityProvider: ILiquidityProvider as ContractArtifact,
    IMooniswapPool: IMooniswapPool as ContractArtifact,
+    IPropertyValidator: IPropertyValidator as ContractArtifact,
+    ITakerCallback: ITakerCallback as ContractArtifact,
    IUniswapV2Pair: IUniswapV2Pair as ContractArtifact,
    IUniswapV3Pool: IUniswapV3Pool as ContractArtifact,
    IERC20Bridge: IERC20Bridge as ContractArtifact,
@@ -307,9 +348,9 @@ export const artifacts = {
    ITestSimpleFunctionRegistryFeature: ITestSimpleFunctionRegistryFeature as ContractArtifact,
    TestBridge: TestBridge as ContractArtifact,
    TestCallTarget: TestCallTarget as ContractArtifact,
-    TestCurve: TestCurve as ContractArtifact,
    TestDelegateCaller: TestDelegateCaller as ContractArtifact,
    TestFeeCollectorController: TestFeeCollectorController as ContractArtifact,
+    TestFeeRecipient: TestFeeRecipient as ContractArtifact,
    TestFillQuoteTransformerBridge: TestFillQuoteTransformerBridge as ContractArtifact,
    TestFillQuoteTransformerExchange: TestFillQuoteTransformerExchange as ContractArtifact,
    TestFillQuoteTransformerHost: TestFillQuoteTransformerHost as ContractArtifact,
@@ -319,33 +360,38 @@ export const artifacts = {
    TestInitialMigration: TestInitialMigration as ContractArtifact,
    TestLibNativeOrder: TestLibNativeOrder as ContractArtifact,
    TestLibSignature: TestLibSignature as ContractArtifact,
-    TestLiquidityProvider: TestLiquidityProvider as ContractArtifact,
    TestMetaTransactionsNativeOrdersFeature: TestMetaTransactionsNativeOrdersFeature as ContractArtifact,
    TestMetaTransactionsTransformERC20Feature: TestMetaTransactionsTransformERC20Feature as ContractArtifact,
    TestMigrator: TestMigrator as ContractArtifact,
    TestMintTokenERC20Transformer: TestMintTokenERC20Transformer as ContractArtifact,
-    TestMintableERC20Token: TestMintableERC20Token as ContractArtifact,
-    TestMooniswap: TestMooniswap as ContractArtifact,
+    TestNFTOrderPresigner: TestNFTOrderPresigner as ContractArtifact,
    TestNativeOrdersFeature: TestNativeOrdersFeature as ContractArtifact,
    TestNoEthRecipient: TestNoEthRecipient as ContractArtifact,
    TestOrderSignerRegistryWithContractWallet: TestOrderSignerRegistryWithContractWallet as ContractArtifact,
    TestPermissionlessTransformerDeployerSuicidal: TestPermissionlessTransformerDeployerSuicidal as ContractArtifact,
    TestPermissionlessTransformerDeployerTransformer: TestPermissionlessTransformerDeployerTransformer as ContractArtifact,
+    TestPropertyValidator: TestPropertyValidator as ContractArtifact,
    TestRfqOriginRegistration: TestRfqOriginRegistration as ContractArtifact,
    TestSimpleFunctionRegistryFeatureImpl1: TestSimpleFunctionRegistryFeatureImpl1 as ContractArtifact,
    TestSimpleFunctionRegistryFeatureImpl2: TestSimpleFunctionRegistryFeatureImpl2 as ContractArtifact,
    TestStaking: TestStaking as ContractArtifact,
-    TestTokenSpenderERC20Token: TestTokenSpenderERC20Token as ContractArtifact,
    TestTransformERC20: TestTransformERC20 as ContractArtifact,
    TestTransformerBase: TestTransformerBase as ContractArtifact,
    TestTransformerDeployerTransformer: TestTransformerDeployerTransformer as ContractArtifact,
    TestTransformerHost: TestTransformerHost as ContractArtifact,
+    TestUniswapV3Feature: TestUniswapV3Feature as ContractArtifact,
+    TestWethTransformerHost: TestWethTransformerHost as ContractArtifact,
+    TestZeroExFeature: TestZeroExFeature as ContractArtifact,
+    TestCurve: TestCurve as ContractArtifact,
+    TestLiquidityProvider: TestLiquidityProvider as ContractArtifact,
+    TestMooniswap: TestMooniswap as ContractArtifact,
    TestUniswapV2Factory: TestUniswapV2Factory as ContractArtifact,
    TestUniswapV2Pool: TestUniswapV2Pool as ContractArtifact,
    TestUniswapV3Factory: TestUniswapV3Factory as ContractArtifact,
-    TestUniswapV3Feature: TestUniswapV3Feature as ContractArtifact,
    TestUniswapV3Pool: TestUniswapV3Pool as ContractArtifact,
+    TestMintableERC1155Token: TestMintableERC1155Token as ContractArtifact,
+    TestMintableERC20Token: TestMintableERC20Token as ContractArtifact,
+    TestMintableERC721Token: TestMintableERC721Token as ContractArtifact,
+    TestTokenSpenderERC20Token: TestTokenSpenderERC20Token as ContractArtifact,
    TestWeth: TestWeth as ContractArtifact,
-    TestWethTransformerHost: TestWethTransformerHost as ContractArtifact,
-    TestZeroExFeature: TestZeroExFeature as ContractArtifact,
 };
--- a/contracts/zero-ex/test/features/erc1155_orders_test.ts
+++ b/contracts/zero-ex/test/features/erc1155_orders_test.ts
--- a/contracts/zero-ex/test/features/erc721_orders_test.ts
+++ b/contracts/zero-ex/test/features/erc721_orders_test.ts
--- a/contracts/zero-ex/test/utils/nft_orders.ts
+++ b/contracts/zero-ex/test/utils/nft_orders.ts
@@ -0,0 +1,41 @@
+import { constants, getRandomInteger, randomAddress } from '@0x/contracts-test-utils';
+import { ERC1155Order, ERC721Order } from '@0x/protocol-utils';
+import { BigNumber } from '@0x/utils';
+
+/**
+ * Generate a random ERC721 Order
+ */
+export function getRandomERC721Order(fields: Partial<ERC721Order> = {}): ERC721Order {
+    return new ERC721Order({
+        erc20Token: randomAddress(),
+        erc20TokenAmount: getRandomInteger('1e18', '10e18'),
+        erc721Token: randomAddress(),
+        erc721TokenId: getRandomInteger(0, constants.MAX_UINT256),
+        maker: randomAddress(),
+        taker: randomAddress(),
+        erc721TokenProperties: [],
+        fees: [],
+        nonce: getRandomInteger(0, constants.MAX_UINT256),
+        expiry: new BigNumber(Math.floor(Date.now() / 1000 + 60)),
+        ...fields,
+    });
+}
+/**
+ * Generate a random ERC1155 Order
+ */
+export function getRandomERC1155Order(fields: Partial<ERC1155Order> = {}): ERC1155Order {
+    return new ERC1155Order({
+        erc20Token: randomAddress(),
+        erc20TokenAmount: getRandomInteger('1e18', '10e18'),
+        erc1155Token: randomAddress(),
+        erc1155TokenId: getRandomInteger(0, constants.MAX_UINT256),
+        erc1155TokenAmount: getRandomInteger(1, '10e18'),
+        maker: randomAddress(),
+        taker: randomAddress(),
+        erc1155TokenProperties: [],
+        fees: [],
+        nonce: getRandomInteger(0, constants.MAX_UINT256),
+        expiry: new BigNumber(Math.floor(Date.now() / 1000 + 60)),
+        ...fields,
+    });
+}
--- a/contracts/zero-ex/test/wrappers.ts
+++ b/contracts/zero-ex/test/wrappers.ts
@@ -9,11 +9,16 @@ export * from '../test/generated-wrappers/bootstrap_feature';
 export * from '../test/generated-wrappers/bridge_adapter';
 export * from '../test/generated-wrappers/bridge_protocols';
 export * from '../test/generated-wrappers/curve_liquidity_provider';
+export * from '../test/generated-wrappers/erc1155_orders_feature';
+export * from '../test/generated-wrappers/erc165_feature';
+export * from '../test/generated-wrappers/erc721_orders_feature';
 export * from '../test/generated-wrappers/fee_collector';
 export * from '../test/generated-wrappers/fee_collector_controller';
 export * from '../test/generated-wrappers/fill_quote_transformer';
 export * from '../test/generated-wrappers/fixin_common';
 export * from '../test/generated-wrappers/fixin_e_i_p712';
+export * from '../test/generated-wrappers/fixin_erc1155_spender';
+export * from '../test/generated-wrappers/fixin_erc721_spender';
 export * from '../test/generated-wrappers/fixin_protocol_fees';
 export * from '../test/generated-wrappers/fixin_reentrancy_guard';
 export * from '../test/generated-wrappers/fixin_token_spender';
@@ -23,9 +28,15 @@ export * from '../test/generated-wrappers/fund_recovery_feature';
 export * from '../test/generated-wrappers/i_batch_fill_native_orders_feature';
 export * from '../test/generated-wrappers/i_bootstrap_feature';
 export * from '../test/generated-wrappers/i_bridge_adapter';
+export * from '../test/generated-wrappers/i_erc1155_orders_feature';
+export * from '../test/generated-wrappers/i_erc1155_token';
+export * from '../test/generated-wrappers/i_erc165_feature';
 export * from '../test/generated-wrappers/i_erc20_bridge';
 export * from '../test/generated-wrappers/i_erc20_transformer';
+export * from '../test/generated-wrappers/i_erc721_orders_feature';
+export * from '../test/generated-wrappers/i_erc721_token';
 export * from '../test/generated-wrappers/i_feature';
+export * from '../test/generated-wrappers/i_fee_recipient';
 export * from '../test/generated-wrappers/i_flash_wallet';
 export * from '../test/generated-wrappers/i_fund_recovery_feature';
 export * from '../test/generated-wrappers/i_liquidity_provider';
@@ -39,8 +50,10 @@ export * from '../test/generated-wrappers/i_native_orders_feature';
 export * from '../test/generated-wrappers/i_otc_orders_feature';
 export * from '../test/generated-wrappers/i_ownable_feature';
 export * from '../test/generated-wrappers/i_pancake_swap_feature';
+export * from '../test/generated-wrappers/i_property_validator';
 export * from '../test/generated-wrappers/i_simple_function_registry_feature';
 export * from '../test/generated-wrappers/i_staking';
+export * from '../test/generated-wrappers/i_taker_callback';
 export * from '../test/generated-wrappers/i_test_simple_function_registry_feature';
 export * from '../test/generated-wrappers/i_token_spender_feature';
 export * from '../test/generated-wrappers/i_transform_erc20_feature';
@@ -52,12 +65,16 @@ export * from '../test/generated-wrappers/i_zero_ex';
 export * from '../test/generated-wrappers/initial_migration';
 export * from '../test/generated-wrappers/lib_bootstrap';
 export * from '../test/generated-wrappers/lib_common_rich_errors';
+export * from '../test/generated-wrappers/lib_erc1155_orders_storage';
 export * from '../test/generated-wrappers/lib_erc20_transformer';
+export * from '../test/generated-wrappers/lib_erc721_orders_storage';
 export * from '../test/generated-wrappers/lib_fee_collector';
 export * from '../test/generated-wrappers/lib_liquidity_provider_rich_errors';
 export * from '../test/generated-wrappers/lib_meta_transactions_rich_errors';
 export * from '../test/generated-wrappers/lib_meta_transactions_storage';
 export * from '../test/generated-wrappers/lib_migrate';
+export * from '../test/generated-wrappers/lib_n_f_t_order';
+export * from '../test/generated-wrappers/lib_n_f_t_orders_rich_errors';
 export * from '../test/generated-wrappers/lib_native_order';
 export * from '../test/generated-wrappers/lib_native_orders_rich_errors';
 export * from '../test/generated-wrappers/lib_native_orders_storage';
@@ -111,6 +128,7 @@ export * from '../test/generated-wrappers/multiplex_rfq';
 export * from '../test/generated-wrappers/multiplex_transform_erc20';
 export * from '../test/generated-wrappers/multiplex_uniswap_v2';
 export * from '../test/generated-wrappers/multiplex_uniswap_v3';
+export * from '../test/generated-wrappers/n_f_t_orders';
 export * from '../test/generated-wrappers/native_orders_cancellation';
 export * from '../test/generated-wrappers/native_orders_feature';
 export * from '../test/generated-wrappers/native_orders_info';
@@ -128,6 +146,7 @@ export * from '../test/generated-wrappers/test_call_target';
 export * from '../test/generated-wrappers/test_curve';
 export * from '../test/generated-wrappers/test_delegate_caller';
 export * from '../test/generated-wrappers/test_fee_collector_controller';
+export * from '../test/generated-wrappers/test_fee_recipient';
 export * from '../test/generated-wrappers/test_fill_quote_transformer_bridge';
 export * from '../test/generated-wrappers/test_fill_quote_transformer_exchange';
 export * from '../test/generated-wrappers/test_fill_quote_transformer_host';
@@ -142,13 +161,17 @@ export * from '../test/generated-wrappers/test_meta_transactions_native_orders_f
 export * from '../test/generated-wrappers/test_meta_transactions_transform_erc20_feature';
 export * from '../test/generated-wrappers/test_migrator';
 export * from '../test/generated-wrappers/test_mint_token_erc20_transformer';
+export * from '../test/generated-wrappers/test_mintable_erc1155_token';
 export * from '../test/generated-wrappers/test_mintable_erc20_token';
+export * from '../test/generated-wrappers/test_mintable_erc721_token';
 export * from '../test/generated-wrappers/test_mooniswap';
+export * from '../test/generated-wrappers/test_n_f_t_order_presigner';
 export * from '../test/generated-wrappers/test_native_orders_feature';
 export * from '../test/generated-wrappers/test_no_eth_recipient';
 export * from '../test/generated-wrappers/test_order_signer_registry_with_contract_wallet';
 export * from '../test/generated-wrappers/test_permissionless_transformer_deployer_suicidal';
 export * from '../test/generated-wrappers/test_permissionless_transformer_deployer_transformer';
+export * from '../test/generated-wrappers/test_property_validator';
 export * from '../test/generated-wrappers/test_rfq_origin_registration';
 export * from '../test/generated-wrappers/test_simple_function_registry_feature_impl1';
 export * from '../test/generated-wrappers/test_simple_function_registry_feature_impl2';
--- a/contracts/zero-ex/tsconfig.json
+++ b/contracts/zero-ex/tsconfig.json
@@ -42,11 +42,16 @@
        "test/generated-artifacts/BridgeAdapter.json",
        "test/generated-artifacts/BridgeProtocols.json",
        "test/generated-artifacts/CurveLiquidityProvider.json",
+        "test/generated-artifacts/ERC1155OrdersFeature.json",
+        "test/generated-artifacts/ERC165Feature.json",
+        "test/generated-artifacts/ERC721OrdersFeature.json",
        "test/generated-artifacts/FeeCollector.json",
        "test/generated-artifacts/FeeCollectorController.json",
        "test/generated-artifacts/FillQuoteTransformer.json",
        "test/generated-artifacts/FixinCommon.json",
        "test/generated-artifacts/FixinEIP712.json",
+        "test/generated-artifacts/FixinERC1155Spender.json",
+        "test/generated-artifacts/FixinERC721Spender.json",
        "test/generated-artifacts/FixinProtocolFees.json",
        "test/generated-artifacts/FixinReentrancyGuard.json",
        "test/generated-artifacts/FixinTokenSpender.json",
@@ -56,9 +61,15 @@
        "test/generated-artifacts/IBatchFillNativeOrdersFeature.json",
        "test/generated-artifacts/IBootstrapFeature.json",
        "test/generated-artifacts/IBridgeAdapter.json",
+        "test/generated-artifacts/IERC1155OrdersFeature.json",
+        "test/generated-artifacts/IERC1155Token.json",
+        "test/generated-artifacts/IERC165Feature.json",
        "test/generated-artifacts/IERC20Bridge.json",
        "test/generated-artifacts/IERC20Transformer.json",
+        "test/generated-artifacts/IERC721OrdersFeature.json",
+        "test/generated-artifacts/IERC721Token.json",
        "test/generated-artifacts/IFeature.json",
+        "test/generated-artifacts/IFeeRecipient.json",
        "test/generated-artifacts/IFlashWallet.json",
        "test/generated-artifacts/IFundRecoveryFeature.json",
        "test/generated-artifacts/ILiquidityProvider.json",
@@ -72,8 +83,10 @@
        "test/generated-artifacts/IOtcOrdersFeature.json",
        "test/generated-artifacts/IOwnableFeature.json",
        "test/generated-artifacts/IPancakeSwapFeature.json",
+        "test/generated-artifacts/IPropertyValidator.json",
        "test/generated-artifacts/ISimpleFunctionRegistryFeature.json",
        "test/generated-artifacts/IStaking.json",
+        "test/generated-artifacts/ITakerCallback.json",
        "test/generated-artifacts/ITestSimpleFunctionRegistryFeature.json",
        "test/generated-artifacts/ITokenSpenderFeature.json",
        "test/generated-artifacts/ITransformERC20Feature.json",
@@ -85,12 +98,16 @@
        "test/generated-artifacts/InitialMigration.json",
        "test/generated-artifacts/LibBootstrap.json",
        "test/generated-artifacts/LibCommonRichErrors.json",
+        "test/generated-artifacts/LibERC1155OrdersStorage.json",
        "test/generated-artifacts/LibERC20Transformer.json",
+        "test/generated-artifacts/LibERC721OrdersStorage.json",
        "test/generated-artifacts/LibFeeCollector.json",
        "test/generated-artifacts/LibLiquidityProviderRichErrors.json",
        "test/generated-artifacts/LibMetaTransactionsRichErrors.json",
        "test/generated-artifacts/LibMetaTransactionsStorage.json",
        "test/generated-artifacts/LibMigrate.json",
+        "test/generated-artifacts/LibNFTOrder.json",
+        "test/generated-artifacts/LibNFTOrdersRichErrors.json",
        "test/generated-artifacts/LibNativeOrder.json",
        "test/generated-artifacts/LibNativeOrdersRichErrors.json",
        "test/generated-artifacts/LibNativeOrdersStorage.json",
@@ -144,6 +161,7 @@
        "test/generated-artifacts/MultiplexTransformERC20.json",
        "test/generated-artifacts/MultiplexUniswapV2.json",
        "test/generated-artifacts/MultiplexUniswapV3.json",
+        "test/generated-artifacts/NFTOrders.json",
        "test/generated-artifacts/NativeOrdersCancellation.json",
        "test/generated-artifacts/NativeOrdersFeature.json",
        "test/generated-artifacts/NativeOrdersInfo.json",
@@ -161,6 +179,7 @@
        "test/generated-artifacts/TestCurve.json",
        "test/generated-artifacts/TestDelegateCaller.json",
        "test/generated-artifacts/TestFeeCollectorController.json",
+        "test/generated-artifacts/TestFeeRecipient.json",
        "test/generated-artifacts/TestFillQuoteTransformerBridge.json",
        "test/generated-artifacts/TestFillQuoteTransformerExchange.json",
        "test/generated-artifacts/TestFillQuoteTransformerHost.json",
@@ -175,13 +194,17 @@
        "test/generated-artifacts/TestMetaTransactionsTransformERC20Feature.json",
        "test/generated-artifacts/TestMigrator.json",
        "test/generated-artifacts/TestMintTokenERC20Transformer.json",
+        "test/generated-artifacts/TestMintableERC1155Token.json",
        "test/generated-artifacts/TestMintableERC20Token.json",
+        "test/generated-artifacts/TestMintableERC721Token.json",
        "test/generated-artifacts/TestMooniswap.json",
+        "test/generated-artifacts/TestNFTOrderPresigner.json",
        "test/generated-artifacts/TestNativeOrdersFeature.json",
        "test/generated-artifacts/TestNoEthRecipient.json",
        "test/generated-artifacts/TestOrderSignerRegistryWithContractWallet.json",
        "test/generated-artifacts/TestPermissionlessTransformerDeployerSuicidal.json",
        "test/generated-artifacts/TestPermissionlessTransformerDeployerTransformer.json",
+        "test/generated-artifacts/TestPropertyValidator.json",
        "test/generated-artifacts/TestRfqOriginRegistration.json",
        "test/generated-artifacts/TestSimpleFunctionRegistryFeatureImpl1.json",
        "test/generated-artifacts/TestSimpleFunctionRegistryFeatureImpl2.json",
--- a/docs/additional/bounties.rst
+++ b/docs/additional/bounties.rst
@@ -2,47 +2,15 @@
 Bounties
 ###############################

-We run an ongoing bug bounty for the 0x Protocol smart contracts! The program is open to anyone and
-rewards up to **$100,000 for critical exploits**. The scope and disclosure instructions are below.

-Rewards
-------
-The severity of reported vulnerabilities will be graded according to the `CVSS <https://www.first.org/cvss/>`_ (Common Vulnerability Scoring Standard).
-The following table will serve as a guideline for reward decisions:
+The bug bounties on this page apply only to the *0x smart contracts* on Ethereum mainnet, Binance Smart Chain, Polygon, Avalanche, Fantom, Celo, Optimism and future deployments in other EVM-compatible networks announced through our official communication channels.  

-+----------------------------+---------------------+
-| **Exploit Score**          | **Reward**          |
-+----------------------------+---------------------+
-| Critical (CVSS 9.0 - 10.0) | $10,000 - $100,000  |
-+----------------------------+---------------------+
-| High (CVSS 7.0 - 8.9)      | $2,500 - $10,000    |
-+----------------------------+---------------------+
-| Medium (CVSS 4.0 - 6.9)    | $1,000 - $2,500     |
-+----------------------------+---------------------+
-| Low (CVSS 0.0 - 3.9)       | $0 - $1,000         |
-+----------------------------+---------------------+
+Bug reports pertaining to 0x API and 0x web interfaces (e.g. Matcha, 0x.org), both in terms of UI/UX or servers/infrastructure, are not eligible. Only the first reporter of a given contract vulnerability will be rewarded, and findings already discovered as part of a formal audit are ineligible. 

-Please note that any rewards will ultimately be awarded at the discretion of ZeroEx Intl. All rewards will be paid out in ZRX. 
+Overview
+--------

-Areas of Interest
-----------------
-
-+---------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------+
-| **Area**                  | **Examples**                                                                                                                                            |
-+---------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------+
-| Loss of funds             | * A user loses funds in a way that they did not explicitly authorize (e.g an account is able to gain access to an ``AssetProxy`` and drain user funds). |
-|                           | * A user authorized a transaction or trade but spends more assets than normally expected (e.g an order is allowed to be over-filled).                   |
-+---------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------+
-| Unintended contract state | * A user is able to update the state of a contract such that it is no longer useable (e.g permanently lock a mutex).                                    |
-|                           | * Any assets get unexpectedly "stuck" in a contract with regular use of the contract's public methods.                                                  |
-|                           | * An action taken in the staking contracts is applied to an incorrect epoch.                                                                            |
-+---------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------+
-| Bypassing time locks      | * The ``ZeroExGovernor`` is allowed to bypass the timelock for transactions where it is not explicitly allowed to do so.                                |
-|                           | * A user is allowed to bypass the ``ZeroExGovernor``.                                                                                                   |
-+---------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------+
-| Incorrect math            | * Overflows or underflow result in unexpected behavior.                                                                                                 |
-|                           | * The staking reward payouts are incorrect.                                                                                                             |
-+---------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------+
+0x has completed smart contract audits with Consensys Diligence, Trail of Bits and ABDK. We run a continuous bug bounty program for the V4 release of the 0x core contracts.

 Scope
 -----
@@ -51,14 +19,14 @@ The following contracts are in scope of the bug bounty. Please note that any bug
 +------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------+
 | **Release**      | **Contracts**                                                                                                                                                                                                                                                                                 | **Commit Hash**                                                                                                                      |
 +------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------+
-| Exchange V4      | * Documentation at `https://0xprotocol.readthedocs.io/en/latest/ <https://0xprotocol.readthedocs.io/en/latest/>`__                                                                                                                                                                            | `72a74e7c66 <https://github.com/0xProject/protocol/tree/72a74e7c66e27da02dd9f4ce604ad057c740c304/contracts/zero-ex/contracts/src>`__ |
-|                  | * `ZeroEx.sol <https://github.com/0xProject/protocol/blob/72a74e7c66e27da02dd9f4ce604ad057c740c304/contracts/zero-ex/contracts/src/ZeroEx.sol>`__                                                                                                                                             |                                                                                                                                      |
-|                  | * `ZeroExOptimized.sol <https://github.com/0xProject/protocol/blob/72a74e7c66e27da02dd9f4ce604ad057c740c304/contracts/zero-ex/contracts/src/ZeroExOptimized.sol>`__                                                                                                                           |                                                                                                                                      |
-|                  | * `external/*.sol <https://github.com/0xProject/protocol/tree/72a74e7c66e27da02dd9f4ce604ad057c740c304/contracts/zero-ex/contracts/src/external>`__                                                                                                                                           |                                                                                                                                      |
-|                  | * `features/**.sol <https://github.com/0xProject/protocol/tree/72a74e7c66e27da02dd9f4ce604ad057c740c304/contracts/zero-ex/contracts/src/features>`__                                                                                                                                          |                                                                                                                                      |
-|                  | * `fixins/*.sol <https://github.com/0xProject/protocol/tree/72a74e7c66e27da02dd9f4ce604ad057c740c304/contracts/zero-ex/contracts/src/fixins>`__                                                                                                                                               |                                                                                                                                      |
-|                  | * `migrations/*.sol <https://github.com/0xProject/protocol/tree/72a74e7c66e27da02dd9f4ce604ad057c740c304/contracts/zero-ex/contracts/src/migrations>`__                                                                                                                                       |                                                                                                                                      |
-|                  | * `storage/*.sol <https://github.com/0xProject/protocol/tree/72a74e7c66e27da02dd9f4ce604ad057c740c304/contracts/zero-ex/contracts/src/storage>`__                                                                                                                                             |                                                                                                                                      |
+| Exchange V4      | * Documentation at `https://protocol.0x.org/en/latest/ <https://protocol.0x.org/en/latest/>`__                                                                                                                                                                                                | `2cbeb9c <https://github.com/0xProject/protocol/tree/audit/nft-orders-address-findings/contracts/zero-ex/contracts/src>`__           |
+|                  | * `ZeroEx.sol <https://github.com/0xProject/protocol/tree/audit/nft-orders-address-findings/contracts/zero-ex/contracts/src/ZeroEx.sol>`__                                                                                                                                                    |                                                                                                                                      |
+|                  | * `ZeroExOptimized.sol <https://github.com/0xProject/protocol/tree/audit/nft-orders-address-findings/contracts/zero-ex/contracts/src/ZeroExOptimized.sol>`__                                                                                                                                  |                                                                                                                                      |
+|                  | * `external/*.sol <https://github.com/0xProject/protocol/tree/audit/nft-orders-address-findings/contracts/zero-ex/contracts/src/external>`__                                                                                                                                                  |                                                                                                                                      |
+|                  | * `features/**.sol <https://github.com/0xProject/protocol/tree/audit/nft-orders-address-findings/contracts/zero-ex/contracts/src/features>`__                                                                                                                                                 |                                                                                                                                      |
+|                  | * `fixins/*.sol <https://github.com/0xProject/protocol/tree/audit/nft-orders-address-findings/contracts/zero-ex/contracts/src/fixins>`__                                                                                                                                                      |                                                                                                                                      |
+|                  | * `migrations/*.sol <https://github.com/0xProject/protocol/tree/audit/nft-orders-address-findings/contracts/zero-ex/contracts/src/migrations>`__                                                                                                                                              |                                                                                                                                      |
+|                  | * `storage/*.sol <https://github.com/0xProject/protocol/tree/audit/nft-orders-address-findings/contracts/zero-ex/contracts/src/storage>`__                                                                                                                                                    |                                                                                                                                      |
 +------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------+
 | Exchange V3      | * `ERC20BridgeProxy.sol <https://github.com/0xProject/0x-monorepo/blob/fb8360edfd4f42f2d2b127b95c156eb1b0daa02b/contracts/asset-proxy/contracts/src/ERC20BridgeProxy.sol>`_ (`spec <https://github.com/0xProject/0x-protocol-specification/blob/master/asset-proxy/erc20-bridge-proxy.md>`__) | `fb8360edfd <https://github.com/0xProject/0x-monorepo/tree/fb8360edfd4f42f2d2b127b95c156eb1b0daa02b/contracts>`__                    |
 |                  | * `Exchange.sol <https://github.com/0xProject/0x-monorepo/blob/fb8360edfd4f42f2d2b127b95c156eb1b0daa02b/contracts/exchange/contracts/src/Exchange.sol>`__ (`spec <https://github.com/0xProject/0x-protocol-specification/blob/master/v3/v3-specification.md>`__)                              |                                                                                                                                      |
@@ -67,7 +35,7 @@ The following contracts are in scope of the bug bounty. Please note that any bug
 |                  | * `StakingProxy.sol <https://github.com/0xProject/0x-monorepo/blob/fb8360edfd4f42f2d2b127b95c156eb1b0daa02b/contracts/staking/contracts/src/StakingProxy.sol>`_ (`spec <https://github.com/0xProject/0x-protocol-specification/blob/master/staking/staking-specification.md>`__)              |                                                                                                                                      |
 |                  | * `ZrxVault.sol <https://github.com/0xProject/0x-monorepo/blob/fb8360edfd4f42f2d2b127b95c156eb1b0daa02b/contracts/staking/contracts/src/ZrxVault.sol>`_ (`spec <https://github.com/0xProject/0x-protocol-specification/blob/master/staking/staking-specification.md>`__)                      |                                                                                                                                      |
 +------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------+
-| Exchange V2.1    | * `src/2.0.0/protocol <https://github.com/0xProject/0x-monorepo/tree/ff70c5ecfe28eff14e1a372c5e493b8f5363e1d0/packages/contracts/src/2.0.0/protocol>`_                                                                                                                                        | `ff70c5ecfe <https://github.com/0xProject/0x-monorepo/tree/ff70c5ecfe28eff14e1a372c5e493b8f5363e1d0/contracts>`_                     |
+| Exchange V2.1    | * `src/2.0.0/protocol <https://github.com/0xProject/0x-monorepo/tree/ff70c5ecfe28eff14e1a372c5e493b8f5363e1d0/packages/contracts/src/2.0.0/protocol>`_                                                                                                                                        | `ff70c5ecfe <https://github.com/0xProject/0x-monorepo/tree/ff70c5ecfe28eff14e1a372c5e493b8f5363e1d0/packages/contracts/src/2.0.0>`_  |
 |                  | * `src/2.0.0/utils <https://github.com/0xProject/0x-monorepo/tree/ff70c5ecfe28eff14e1a372c5e493b8f5363e1d0/packages/contracts/src/2.0.0/utils>`_                                                                                                                                              |                                                                                                                                      |
 +------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------+
 | MultiAssetProxy  | * `MultiAssetProxy.sol <https://github.com/0xProject/0x-monorepo/blob/c4d9ef9f83508154fe9db35796b6b86aeb0f2240/contracts/asset-proxy/contracts/src/MultiAssetProxy.sol>`_                                                                                                                     | `c4d9ef9f83 <https://github.com/0xProject/0x-monorepo/tree/c4d9ef9f83508154fe9db35796b6b86aeb0f2240/contracts>`_                     |
@@ -78,9 +46,37 @@ The following contracts are in scope of the bug bounty. Please note that any bug
 +------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------+
 | ERC20BridgeProxy | * `ERC20BridgeProxy.sol <https://github.com/0xProject/0x-monorepo/blob/281658ba349a2c5088b40b503998bea5020284a6/contracts/asset-proxy/contracts/src/ERC20BridgeProxy.sol>`__                                                                                                                  | `281658ba34 <https://github.com/0xProject/0x-monorepo/tree/281658ba349a2c5088b40b503998bea5020284a6/contracts>`_                     |
 +------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------+
-| ExchangeProxy    | * `contracts/src <https://github.com/0xProject/0x-monorepo/tree/7967a8416c76e34ff5a0a4eb80e7b33ff8c0e297/contracts/zero-ex>`__                                                                                                                                                                | `7967a8416c <https://github.com/0xProject/0x-monorepo/tree/7967a8416c76e34ff5a0a4eb80e7b33ff8c0e297/contracts>`_                     |
+| ExchangeProxy    | * `contracts/src <https://github.com/0xProject/protocol/tree/audit/nft-orders-address-findings/contracts/zero-ex/contracts/src>`__                                                                                                                                                            | `2cbeb9c <https://github.com/0xProject/protocol/tree/audit/nft-orders-address-findings/contracts/zero-ex/contracts/src>`_            |
 +------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------------------------------------------------+

+Bounties
+--------
+The bounty program will pay out rewards according to the severity of a vulnerability. The severity of reported vulnerabilities will be graded according to the `CVSS <https://www.first.org/cvss/>`__ (Common Vulnerability Scoring Standard).
+
+The final reward amount is at the sole discretion of 0x Labs and will be paid in the specified sum in either USD or ETH. 
+
+----------------------------+---------------------+
+| **Exploit Score**          | **Reward**          |
+----------------------------+---------------------+
+| Critical (CVSS 9.0 - 10.0) | up to $1,000,000    |
+----------------------------+---------------------+
+| High (CVSS 7.0 - 8.9)      | up to $350,000      |
+----------------------------+---------------------+
+| Medium (CVSS 4.0 - 6.9)    | up to $35,000       |
+----------------------------+---------------------+
+| Low (CVSS 0.0 - 3.9)       | up to $5,000        |
+----------------------------+---------------------+
+
+Recent Inclusions 
+-----------------
+
+---------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------+
+| **Change**                | ****                                                                                                                                                    |
+---------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------+
+| NFT feature               | * Trade ERC721 and ERC1155 assets. See `ZEIP-93 <https://github.com/0xProject/ZEIPs/issues/93>`__ for more details                                      |
+---------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------+
+
+
 Disclosures
 -----------
 Please e-mail all submissions to security@0x.org with the subject "BUG BOUNTY". Your submission 
--- a/docs/additional/exceptional_erc20s.rst
+++ b/docs/additional/exceptional_erc20s.rst
@@ -17,3 +17,10 @@ Known tokens:
 - LINK
 - sUSD
 - USDT
+
+Tokens with Fees on Transfer
+----------------------------
+These tokens do not follow the ERC20 specification. As such the protocol expects the transfer to transfer
+the specified amount, or revert. Since tokens with transfer fees do not meet this criteria, the behaviour
+of the protocol with these tokens is unspecified. In most cases it will result in an overall transaction failure
+due to various slippage protections.
--- a/docs/additional/releases.rst
+++ b/docs/additional/releases.rst
@@ -17,10 +17,12 @@ This page outlines upcoming releases and expected changes.
    +---------------------------------------------+---------------------------------------------------------------+----------------------+-------------+-------------------------------------------------------------------------------------------------------------------------------------+
    | **Name**                                    | **Overview**                                                  | **Est Release Date** | **Status**  | **Additional**                                                                                                                      |
    +---------------------------------------------+---------------------------------------------------------------+----------------------+-------------+-------------------------------------------------------------------------------------------------------------------------------------+
-    | `Amaretto`_                                 | Protocol 4.1: Efficiency + Batch Fills                        | 03/15/21             | Development |                                                                                                                                     |
+    | `Nifty`_                                    | ERC721 and ERC1155 support                                    | 02/14/22             | Vote        |                                                                                                                                     |
    +---------------------------------------------+---------------------------------------------------------------+----------------------+-------------+-------------------------------------------------------------------------------------------------------------------------------------+
    | *The following releases have been deployed* |                                                               |                      |             |                                                                                                                                     |
    +---------------------------------------------+---------------------------------------------------------------+----------------------+-------------+-------------------------------------------------------------------------------------------------------------------------------------+
+    | `Amaretto`_                                 | Protocol 4.1: Efficiency + Batch Fills                        | 03/15/21             | Deployed    |                                                                                                                                     |
+    +---------------------------------------------+---------------------------------------------------------------+----------------------+-------------+-------------------------------------------------------------------------------------------------------------------------------------+
    | `Babooshka`_                                | Connect Exchange Proxy to Staking                             | 02/08/21             | Deployed    | `Release Notes <https://github.com/0xProject/0x-migrations/blob/main/src/exchange-proxy/migrations/log/9_babooshka.md>`__           |
    +---------------------------------------------+---------------------------------------------------------------+----------------------+-------------+-------------------------------------------------------------------------------------------------------------------------------------+
    | `Squire`_                                   | Aggregation for `V4 Orders <../basics/orders.html>`_          | 02/04/21             | Deployed    | N/A                                                                                                                                 |
@@ -45,6 +47,19 @@ This page outlines upcoming releases and expected changes.
 Upcoming
 ========

+Nifty
+--------
+
+- ERC721 and ERC1155 order types
+- Batch fills for NFT orders
+- Property based orders
+- Ability to receive ETH in NFT orders
+
+
+
+Past
+=====
+
 Amaretto
 --------

@@ -53,10 +68,6 @@ Amaretto
 - Mooniswap VIP
 - Curve / Swerve VIP (via PLP Sandbox)

-
-Past
-=====
-
 Babooshka
 ----------

--- a/docs/advanced/erc20_transformations.rst
+++ b/docs/advanced/erc20_transformations.rst
@@ -57,18 +57,22 @@ Liquidity Aggregation

 Liquidity can be pulled from other Decentralized Exchanges (DEX) to supplement native liquidity (0x orders). This is currently used by 0x API to provide the aggregate the best prices across the entire DEX Ecosystem. Check out `https://matcha.xyz <https://matcha.xyz>`_ to see this in action!

-Supported DEX's:
+Below are just a few of the Supported DEX's on Ethereum:

-* Balancer
+* Balancer v1/v2
+* Bancor v1/v2
 * Curve
-* DoDo
+* Dodo v1/v2
 * Kyber
+* MakerPSM
 * MStable
 * Mooniswap
 * Oasis
 * Shell
 * Sushiswap
-* Uniswap v1/v2
+* Shibaswap
+* Smoothy
+* Uniswap v1/v2/v3

 This transformation is implemented by the `FillQuoteTransformer <../architecture/transformers.html>`_. Abi-Encode the following struct to get the ``data``:

--- a/docs/basics/addresses.rst
+++ b/docs/basics/addresses.rst
@@ -6,16 +6,17 @@ Addresses
 .. note::
    This page is auto-generated. See the `contract-addresses <https://github.com/0xProject/protocol/blob/development/packages/contract-addresses/addresses.json>`_ package for an exhaustive list of contracts across all networks.

+    The Exchange Proxy may have different addresses on various networks, see the `Exchange Proxy Addresses <./addresses.html#exchange-proxy-addresses>`__ table for an exhaustive list.
+
 Exchange V4
 ===================
 .. csv-table::

-    exchangeProxy, `0xdef1c0ded9bec7f1a1670819833240f027b25eff <https://etherscan.io/address//0xdef1c0ded9bec7f1a1670819833240f027b25eff>`_
-    exchangeProxyAllowanceTarget, `0xf740b67da229f2f10bcbd38a7979992fcc71b8eb <https://etherscan.io/address//0xf740b67da229f2f10bcbd38a7979992fcc71b8eb>`_
-    exchangeProxyFlashWallet, `0x22f9dcf4647084d6c31b2765f6910cd85c178c18 <https://etherscan.io/address//0x22f9dcf4647084d6c31b2765f6910cd85c178c18>`_
-    exchangeProxyGovernor, `0x618f9c67ce7bf1a50afa1e7e0238422601b0ff6e <https://etherscan.io/address//0x618f9c67ce7bf1a50afa1e7e0238422601b0ff6e>`_
-    exchangeProxyLiquidityProviderSandbox, `0x407b4128e9ecad8769b2332312a9f655cb9f5f3a <https://etherscan.io/address//0x407b4128e9ecad8769b2332312a9f655cb9f5f3a>`_
-    exchangeProxyTransformerDeployer, `0x39dce47a67ad34344eab877eae3ef1fa2a1d50bb <https://etherscan.io/address//0x39dce47a67ad34344eab877eae3ef1fa2a1d50bb>`_
+    exchangeProxy, `0xdef1c0ded9bec7f1a1670819833240f027b25eff <https://etherscan.io/address/0xdef1c0ded9bec7f1a1670819833240f027b25eff>`__
+    exchangeProxyFlashWallet, `0x22f9dcf4647084d6c31b2765f6910cd85c178c18 <https://etherscan.io/address/0x22f9dcf4647084d6c31b2765f6910cd85c178c18>`__
+    exchangeProxyGovernor, `0x618f9c67ce7bf1a50afa1e7e0238422601b0ff6e <https://etherscan.io/address/0x618f9c67ce7bf1a50afa1e7e0238422601b0ff6e>`__
+    exchangeProxyLiquidityProviderSandbox, `0x407b4128e9ecad8769b2332312a9f655cb9f5f3a <https://etherscan.io/address/0x407b4128e9ecad8769b2332312a9f655cb9f5f3a>`__
+    exchangeProxyTransformerDeployer, `0x39dce47a67ad34344eab877eae3ef1fa2a1d50bb <https://etherscan.io/address/0x39dce47a67ad34344eab877eae3ef1fa2a1d50bb>`__



@@ -23,10 +24,11 @@ Transformers
 ===================
 .. csv-table::

-    wethTransformer, `0xb2bc06a4efb20fc6553a69dbfa49b7be938034a7 <https://etherscan.io/address//0xb2bc06a4efb20fc6553a69dbfa49b7be938034a7>`_
-    payTakerTransformer, `0x4638a7ebe75b911b995d0ec73a81e4f85f41f24e <https://etherscan.io/address//0x4638a7ebe75b911b995d0ec73a81e4f85f41f24e>`_
-    fillQuoteTransformer, `0x5ce5174d7442061135ea849970ffc7763920e0fd <https://etherscan.io/address//0x5ce5174d7442061135ea849970ffc7763920e0fd>`_
-    affiliateFeeTransformer, `0xda6d9fc5998f550a094585cf9171f0e8ee3ac59f <https://etherscan.io/address//0xda6d9fc5998f550a094585cf9171f0e8ee3ac59f>`_
+    wethTransformer, `0xb2bc06a4efb20fc6553a69dbfa49b7be938034a7 <https://etherscan.io/address/0xb2bc06a4efb20fc6553a69dbfa49b7be938034a7>`__
+    payTakerTransformer, `0x4638a7ebe75b911b995d0ec73a81e4f85f41f24e <https://etherscan.io/address/0x4638a7ebe75b911b995d0ec73a81e4f85f41f24e>`__
+    affiliateFeeTransformer, `0xda6d9fc5998f550a094585cf9171f0e8ee3ac59f <https://etherscan.io/address/0xda6d9fc5998f550a094585cf9171f0e8ee3ac59f>`__
+    fillQuoteTransformer, `0xb4fa284689c9784a60d840eb136bb16c5246191f <https://etherscan.io/address/0xb4fa284689c9784a60d840eb136bb16c5246191f>`__
+    positiveSlippageFeeTransformer, `0xa9416ce1dbde8d331210c07b5c253d94ee4cc3fd <https://etherscan.io/address/0xa9416ce1dbde8d331210c07b5c253d94ee4cc3fd>`__



@@ -34,10 +36,10 @@ ZRX / Staking
 ===================
 .. csv-table::

-    staking, `0x2a17c35ff147b32f13f19f2e311446eeb02503f3 <https://etherscan.io/address//0x2a17c35ff147b32f13f19f2e311446eeb02503f3>`_
-    stakingProxy, `0xa26e80e7dea86279c6d778d702cc413e6cffa777 <https://etherscan.io/address//0xa26e80e7dea86279c6d778d702cc413e6cffa777>`_
-    zrxToken, `0xe41d2489571d322189246dafa5ebde1f4699f498 <https://etherscan.io/address//0xe41d2489571d322189246dafa5ebde1f4699f498>`_
-    zrxVault, `0xba7f8b5fb1b19c1211c5d49550fcd149177a5eaf <https://etherscan.io/address//0xba7f8b5fb1b19c1211c5d49550fcd149177a5eaf>`_
+    staking, `0x2a17c35ff147b32f13f19f2e311446eeb02503f3 <https://etherscan.io/address/0x2a17c35ff147b32f13f19f2e311446eeb02503f3>`__
+    stakingProxy, `0xa26e80e7dea86279c6d778d702cc413e6cffa777 <https://etherscan.io/address/0xa26e80e7dea86279c6d778d702cc413e6cffa777>`__
+    zrxToken, `0xe41d2489571d322189246dafa5ebde1f4699f498 <https://etherscan.io/address/0xe41d2489571d322189246dafa5ebde1f4699f498>`__
+    zrxVault, `0xba7f8b5fb1b19c1211c5d49550fcd149177a5eaf <https://etherscan.io/address/0xba7f8b5fb1b19c1211c5d49550fcd149177a5eaf>`__



@@ -45,9 +47,22 @@ Miscellaneous
 ===================
 .. csv-table::

-    devUtils, `0x74134cf88b21383713e096a5ecf59e297dc7f547 <https://etherscan.io/address//0x74134cf88b21383713e096a5ecf59e297dc7f547>`_
-    etherToken, `0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2 <https://etherscan.io/address//0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2>`_
-    erc20BridgeSampler, `0xd8c38704c9937ea3312de29f824b4ad3450a5e61 <https://etherscan.io/address//0xd8c38704c9937ea3312de29f824b4ad3450a5e61>`_
+    devUtils, `0x74134cf88b21383713e096a5ecf59e297dc7f547 <https://etherscan.io/address/0x74134cf88b21383713e096a5ecf59e297dc7f547>`__
+    etherToken, `0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2 <https://etherscan.io/address/0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2>`__
+    erc20BridgeSampler, `0xd8c38704c9937ea3312de29f824b4ad3450a5e61 <https://etherscan.io/address/0xd8c38704c9937ea3312de29f824b4ad3450a5e61>`__



+Exchange Proxy Addresses 
+=========================
+Note: Some addresses have changed across various networks
+
+.. csv-table::
+
+    Ethereum, `0xdef1c0ded9bec7f1a1670819833240f027b25eff <https://etherscan.io/address/0xdef1c0ded9bec7f1a1670819833240f027b25eff>`__
+    Optimism, `0xdef1abe32c034e558cdd535791643c58a13acc10 <https://optimistic.etherscan.io/address/0xdef1abe32c034e558cdd535791643c58a13acc10>`__
+    Binance Smart Chain, `0xdef1c0ded9bec7f1a1670819833240f027b25eff <https://bscscan.com/address/0xdef1c0ded9bec7f1a1670819833240f027b25eff>`__
+    Polygon, `0xdef1c0ded9bec7f1a1670819833240f027b25eff <https://polygonscan.com/address/0xdef1c0ded9bec7f1a1670819833240f027b25eff>`__
+    Avalanche, `0xdef1c0ded9bec7f1a1670819833240f027b25eff <https://snowtrace.io/address/0xdef1c0ded9bec7f1a1670819833240f027b25eff>`__
+    Fantom, `0xdef189deaef76e379df891899eb5a00a94cbc250 <https://ftmscan.com/address/0xdef189deaef76e379df891899eb5a00a94cbc250>`__
+    Celo, `0xdef1c0ded9bec7f1a1670819833240f027b25eff <https://explorer.celo.org/address/0xdef1c0ded9bec7f1a1670819833240f027b25eff>`__
--- a/docs/basics/allowances.rst
+++ b/docs/basics/allowances.rst
@@ -2,6 +2,4 @@
 Allowances
 ###############################

-Both maker and taker allowance should be be set directly on the `Exchange Proxy contract <./addresses.html#exchange-v4>`_.
-
-For takers, legacy allowances set on the `Allowance Target <./addresses.html#exchange-v4>`_ will continue to work during this transition period but will suffer a gas penalty. It's highly encouraged to migrate allowances over to the Exchange Proxy as soon as possible to avoid interruption.
+Both maker and taker allowance should be be set directly on the `Exchange Proxy contract <./addresses.html#exchange-proxy-addresses>`_.
--- a/docs/basics/events.rst
+++ b/docs/basics/events.rst
@@ -61,6 +61,18 @@ illustrates how events are emitted when trading through the Exchange Proxy.
 +-------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------+---------------------+
 | `TransformerMetadata`_        | A general, customizable event emitted that can be emitted by transformers as-needed.                                                                      | FlashWallet         |
 +-------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------+---------------------+
+| `ERC1155OrderFilled`_         | Emitted when a `V4 ERC1155 Order <./orders.html#erc1155-orders>`_ is filled.                                                                              | ExchangeProxy       |
+-------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------+---------------------+
+| `ERC721OrderFilled`_          | Emitted when a `V4 ERC721 Order <./orders.html#erc721-orders>`_ is filled.                                                                                | ExchangeProxy       |
+-------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------+---------------------+
+| `ERC1155OrderCancelled`_      | Emitted when a `V4 ERC1155 Order <./orders.html#erc1155-orders>`_ is cancelled.                                                                           | ExchangeProxy       |
+-------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------+---------------------+
+| `ERC721OrderCancelled`_       | Emitted when a `V4 ERC721 Order <./orders.html#erc721-orders>`_ is cancelled.                                                                             | ExchangeProxy       |
+-------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------+---------------------+
+| `ERC1155OrderPreSigned`_      | Emitted when a `V4 ERC1155 Order <./orders.html#erc1155-orders>`_ is signed on-chain.                                                                     | ExchangeProxy       |
+-------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------+---------------------+
+| `ERC721OrderPreSigned`_       | Emitted when a `V4 ERC721 Order <./orders.html#erc721-orders>`_ is signed on-chain.                                                                       | ExchangeProxy       |
+-------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------+---------------------+


 Deployed
@@ -374,6 +386,143 @@ TransformerMetadata
    );


+ERC721OrderFilled
+-------------------
+
+.. code-block:: solidity
+
+    /// @dev Emitted whenever an `ERC721Order` is filled.
+    /// @param direction Whether the order is selling or
+    ///        buying the ERC721 token.
+    /// @param maker The maker of the order.
+    /// @param taker The taker of the order.
+    /// @param nonce The unique maker nonce in the order.
+    /// @param erc20Token The address of the ERC20 token.
+    /// @param erc20TokenAmount The amount of ERC20 token
+    ///        to sell or buy.
+    /// @param erc721Token The address of the ERC721 token.
+    /// @param erc721TokenId The ID of the ERC721 asset.
+    /// @param matcher If this order was matched with another using `matchERC721Orders()`,
+    ///                this will be the address of the caller. If not, this will be `address(0)`.
+    event ERC721OrderFilled(
+        LibNFTOrder.TradeDirection direction,
+        address maker,
+        address taker,
+        uint256 nonce,
+        IERC20TokenV06 erc20Token,
+        uint256 erc20TokenAmount,
+        IERC721Token erc721Token,
+        uint256 erc721TokenId,
+        address matcher
+    );
+
+ERC721OrderCancelled
+---------------------
+
+.. code-block:: solidity
+
+    /// @dev Emitted whenever an `ERC721Order` is cancelled.
+    /// @param maker The maker of the order.
+    /// @param nonce The nonce of the order that was cancelled.
+    event ERC721OrderCancelled(
+        address maker,
+        uint256 nonce
+    );
+
+ERC721OrderPreSigned
+---------------------
+
+.. code-block:: solidity
+
+
+    /// @dev Emitted when an `ERC721Order` is pre-signed.
+    ///      Contains all the fields of the order.
+    event ERC721OrderPreSigned(
+        LibNFTOrder.TradeDirection direction,
+        address maker,
+        address taker,
+        uint256 expiry,
+        uint256 nonce,
+        IERC20TokenV06 erc20Token,
+        uint256 erc20TokenAmount,
+        LibNFTOrder.Fee[] fees,
+        IERC721Token erc721Token,
+        uint256 erc721TokenId,
+        LibNFTOrder.Property[] erc721TokenProperties
+    );
+
+ERC1155OrderFilled
+-------------------
+
+.. code-block:: solidity
+
+    /// @dev Emitted whenever an `ERC1155Order` is filled.
+    /// @param direction Whether the order is selling or
+    ///        buying the ERC1155 token.
+    /// @param maker The maker of the order.
+    /// @param taker The taker of the order.
+    /// @param nonce The unique maker nonce in the order.
+    /// @param erc20Token The address of the ERC20 token.
+    /// @param erc20FillAmount The amount of ERC20 token filled.
+    /// @param erc1155Token The address of the ERC1155 token.
+    /// @param erc1155TokenId The ID of the ERC1155 asset.
+    /// @param erc1155FillAmount The amount of ERC1155 asset filled.
+    /// @param matcher Currently unused.
+    event ERC1155OrderFilled(
+        LibNFTOrder.TradeDirection direction,
+        address maker,
+        address taker,
+        uint256 nonce,
+        IERC20TokenV06 erc20Token,
+        uint256 erc20FillAmount,
+        IERC1155Token erc1155Token,
+        uint256 erc1155TokenId,
+        uint128 erc1155FillAmount,
+        address matcher
+    );
+
+ERC1155OrderCancelled
+---------------------
+
+.. code-block:: solidity
+
+    /// @dev Emitted whenever an `ERC1155Order` is cancelled.
+    /// @param orderHash The hash the order.
+    /// @param maker The maker of the order.
+    event ERC1155OrderCancelled(
+        bytes32 orderHash,
+        address maker
+    );
+
+ERC1155OrderPreSigned
+---------------------
+
+.. code-block:: solidity
+
+    /// @dev Emitted when an `ERC1155Order` is pre-signed.
+    ///      Contains all the fields of the order.
+    event ERC1155OrderPreSigned(
+        LibNFTOrder.TradeDirection direction,
+        address maker,
+        address taker,
+        uint256 expiry,
+        uint256 nonce,
+        IERC20TokenV06 erc20Token,
+        uint256 erc20TokenAmount,
+        LibNFTOrder.Fee[] fees,
+        IERC1155Token erc1155Token,
+        uint256 erc1155TokenId,
+        LibNFTOrder.Property[] erc1155TokenProperties,
+        uint128 erc1155TokenAmount
+    );
+
+
+
+
+
+
+
+



--- a/docs/basics/functions.rst
+++ b/docs/basics/functions.rst
@@ -67,6 +67,46 @@ Below is a catalog of basic Exchange functionality. For more advanced usage, lik
 | `transferProtocolFeesForPools`_         | Transfers protocol fees from escrow to the 0x Staking System.            |
 |                                         | This should be called near the end of each epoch.                        |
 +-----------------------------------------+--------------------------------------------------------------------------+
+| **NFT Orders**                          | **Overview**                                                             |
+-----------------------------------------+--------------------------------------------------------------------------+
+| `sellERC721`_                           | These are specialised orders for NFT trading                             |
+-----------------------------------------+                                                                          |
+| `buyERC721`_                            |                                                                          |
+-----------------------------------------+                                                                          |
+| `batchBuyERC721s`_                      |                                                                          |
+-----------------------------------------+                                                                          |
+| `matchERC721Orders`_                    |                                                                          |
+-----------------------------------------+                                                                          |
+| `batchMatchERC721Orders`_               |                                                                          |
+-----------------------------------------+                                                                          |
+| `preSignERC721Order`_                   |                                                                          |
+-----------------------------------------+                                                                          |
+| `validateERC721OrderSignature`_         |                                                                          |
+-----------------------------------------+                                                                          |
+| `validateERC721OrderProperties`_        |                                                                          |
+-----------------------------------------+                                                                          |
+| `getERC721OrderStatus`_                 |                                                                          |
+-----------------------------------------+                                                                          |
+| `getERC721OrderHash`_                   |                                                                          |
+-----------------------------------------+                                                                          +
+| `sellERC1155`_                          |                                                                          |
+-----------------------------------------+                                                                          +
+| `buyERC1155`_                           |                                                                          |
+-----------------------------------------+                                                                          +
+| `batchCancelERC1155Orders`_             |                                                                          |
+-----------------------------------------+                                                                          +
+| `batchBuyERC1155s`_                     |                                                                          |
+-----------------------------------------+                                                                          +
+| `preSignERC1155Order`_                  |                                                                          |
+-----------------------------------------+                                                                          +
+| `validateERC1155OrderSignature`_        |                                                                          |
+-----------------------------------------+                                                                          +
+| `validateERC1155OrderProperties`_       |                                                                          |
+-----------------------------------------+                                                                          +
+| `getERC1155OrderInfo`_                  |                                                                          |
+-----------------------------------------+                                                                          +
+| `getERC1155OrderHash`_                  |                                                                          |
+-----------------------------------------+--------------------------------------------------------------------------+


 Limit Orders
@@ -733,3 +773,490 @@ This function transfers protocol fees from `Fee Collectors <../architecture/fee_
    /// @param poolIds Staking pool IDs
    function transferProtocolFeesForPools(bytes32[] calldata poolIds)
        external;
+
+
+
+NFT Orders
+==========
+
+
+sellERC721
+----------------------------
+
+This function sells an ERC721 token given a buy order.
+
+.. code-block:: solidity
+
+    /// @dev Sells an ERC721 asset to fill the given order.
+    /// @param buyOrder The ERC721 buy order.
+    /// @param signature The order signature from the maker.
+    /// @param erc721TokenId The ID of the ERC721 asset being
+    ///        sold. If the given order specifies properties,
+    ///        the asset must satisfy those properties. Otherwise,
+    ///        it must equal the tokenId in the order.
+    /// @param unwrapNativeToken If this parameter is true and the
+    ///        ERC20 token of the order is e.g. WETH, unwraps the
+    ///        token before transferring it to the taker.
+    /// @param callbackData If this parameter is non-zero, invokes
+    ///        `zeroExERC721OrderCallback` on `msg.sender` after
+    ///        the ERC20 tokens have been transferred to `msg.sender`
+    ///        but before transferring the ERC721 asset to the buyer.
+    function sellERC721(
+        LibNFTOrder.ERC721Order _calldata_ buyOrder,
+        LibSignature.Signature _calldata_ signature,
+        uint256 erc721TokenId,
+        bool unwrapNativeToken,
+        bytes _calldata_ callbackData
+    )
+        _external_;
+
+
+buyERC721
+----------------------------
+
+This function buys an ERC721 token given a sell order.
+
+.. code-block:: solidity
+
+    
+    /// @dev Buys an ERC721 asset by filling the given order.
+    /// @param sellOrder The ERC721 sell order.
+    /// @param signature The order signature.
+    /// @param callbackData If this parameter is non-zero, invokes
+    ///        `zeroExERC721OrderCallback` on `msg.sender` after
+    ///        the ERC721 asset has been transferred to `msg.sender`
+    ///        but before transferring the ERC20 tokens to the seller.
+    ///        Native tokens acquired during the callback can be used
+    ///        to fill the order.
+    function buyERC721(
+        LibNFTOrder.ERC721Order _calldata_ sellOrder,
+        LibSignature.Signature _calldata_ signature,
+        bytes _calldata_ callbackData
+    )
+        _external_
+        _payable_;
+
+
+cancelERC721Order
+----------------------------
+
+This function cancels an ERC721 order using the order `nonce` field.
+
+.. code-block:: solidity
+    
+    /// @dev Cancel a single ERC721 order by its nonce. The caller
+    ///      should be the maker of the order. Silently succeeds if
+    ///      an order with the same nonce has already been filled or
+    ///      cancelled.
+    /// @param orderNonce The order nonce.
+    function cancelERC721Order(uint256 orderNonce)
+        _external_;
+
+
+batchCancelERC721Orders
+----------------------------
+
+This function cancels an number of ERC721 order using the order `nonce` field.
+
+.. code-block:: solidity
+
+    /// @dev Cancel multiple ERC721 orders by their nonces. The caller
+    ///      should be the maker of the orders. Silently succeeds if
+    ///      an order with the same nonce has already been filled or
+    ///      cancelled.
+    /// @param orderNonces The order nonces.
+    function batchCancelERC721Orders(uint256[] _calldata_ orderNonces)
+        _external_;
+
+batchBuyERC721s
+----------------------------
+
+This function buys a number of ERC721's. If you wish the transaction to revert unless ALL NFT's are purchased, set `revertIfIncomplete` to true.
+
+.. code-block:: solidity
+    
+    /// @dev Buys multiple ERC721 assets by filling the
+    ///      given orders.
+    /// @param sellOrders The ERC721 sell orders.
+    /// @param signatures The order signatures.
+    /// @param revertIfIncomplete If true, reverts if this
+    ///        function fails to fill any individual order.
+    /// @return successes An array of booleans corresponding to whether
+    ///         each order in `orders` was successfully filled.
+    function batchBuyERC721s(
+        LibNFTOrder.ERC721Order[] _calldata_ sellOrders,
+        LibSignature.Signature[] _calldata_ signatures,
+        bool revertIfIncomplete
+    )
+        _external_
+        _payable_
+        returns (bool[] _memory_ successes);
+
+matchERC721Orders
+----------------------------
+
+This function matches a buy order and a sell order together. The matcher receives any spread in price.
+
+.. code-block:: solidity
+    
+    /// @dev Matches a pair of complementary orders that have
+    ///      a non-negative spread. Each order is filled at
+    ///      their respective price, and the matcher receives
+    ///      a profit denominated in the ERC20 token.
+    /// @param sellOrder Order selling an ERC721 asset.
+    /// @param buyOrder Order buying an ERC721 asset.
+    /// @param sellOrderSignature Signature for the sell order.
+    /// @param buyOrderSignature Signature for the buy order.
+    /// @return profit The amount of profit earned by the caller
+    ///         of this function (denominated in the ERC20 token
+    ///         of the matched orders).
+    function matchERC721Orders(
+        LibNFTOrder.ERC721Order _calldata_ sellOrder,
+        LibNFTOrder.ERC721Order _calldata_ buyOrder,
+        LibSignature.Signature _calldata_ sellOrderSignature,
+        LibSignature.Signature _calldata_ buyOrderSignature
+    )
+        _external_
+        returns (uint256 profit);
+
+
+batchMatchERC721Orders
+----------------------------
+
+This function matches a buy orders and a sell orders together. The matcher receives any spread in price.
+
+.. code-block:: solidity
+    
+    /// @dev Matches pairs of complementary orders that have
+    ///      non-negative spreads. Each order is filled at
+    ///      their respective price, and the matcher receives
+    ///      a profit denominated in the ERC20 token.
+    /// @param sellOrders Orders selling ERC721 assets.
+    /// @param buyOrders Orders buying ERC721 assets.
+    /// @param sellOrderSignatures Signatures for the sell orders.
+    /// @param buyOrderSignatures Signatures for the buy orders.
+    /// @return profits The amount of profit earned by the caller
+    ///         of this function for each pair of matched orders
+    ///         (denominated in the ERC20 token of the order pair).
+    /// @return successes An array of booleans corresponding to
+    ///         whether each pair of orders was successfully matched.
+    function batchMatchERC721Orders(
+        LibNFTOrder.ERC721Order[] _calldata_ sellOrders,
+        LibNFTOrder.ERC721Order[] _calldata_ buyOrders,
+        LibSignature.Signature[] _calldata_ sellOrderSignatures,
+        LibSignature.Signature[] _calldata_ buyOrderSignatures
+    )
+        _external_
+        returns (uint256[] _memory_ profits, bool[] _memory_ successes);
+    
+    
+preSignERC721Order
+----------------------------
+
+This function pre-signs an order. Useful for contracts that wish to buy or sell an NFT.
+
+.. code-block:: solidity
+
+    /// @dev Approves an ERC721 order on-chain. After pre-signing
+    ///      the order, the `PRESIGNED` signature type will become
+    ///      valid for that order and signer.
+    /// @param order An ERC721 order.
+    function preSignERC721Order(LibNFTOrder.ERC721Order _calldata_ order)
+        _external_;        
+
+validateERC721OrderSignature
+----------------------------
+
+A read function to validate an ERC721 order signature.
+
+.. code-block:: solidity
+
+    /// @dev Checks whether the given signature is valid for the
+    ///      the given ERC721 order. Reverts if not.
+    /// @param order The ERC721 order.
+    /// @param signature The signature to validate.
+    function validateERC721OrderSignature(
+        LibNFTOrder.ERC721Order _calldata_ order,
+        LibSignature.Signature _calldata_ signature
+    )
+        _external_
+        _view_;
+    
+
+validateERC721OrderProperties
+---------------------------------
+
+A read function to validate a property based order with a particular token id.
+
+.. code-block:: solidity
+
+    /// @dev If the given order is buying an ERC721 asset, checks
+    ///      whether or not the given token ID satisfies the required
+    ///      properties specified in the order. If the order does not
+    ///      specify any properties, this function instead checks
+    ///      whether the given token ID matches the ID in the order.
+    ///      Reverts if any checks fail, or if the order is selling
+    ///      an ERC721 asset.
+    /// @param order The ERC721 order.
+    /// @param erc721TokenId The ID of the ERC721 asset.
+    function validateERC721OrderProperties(
+        LibNFTOrder.ERC721Order _calldata_ order,
+        uint256 erc721TokenId
+    )
+        _external_
+        _view_;
+
+
+getERC721OrderStatus
+----------------------------
+
+A read function to return the order status. E.g whether it is filled, cancelled or expired.
+
+.. code-block:: solidity
+    
+    /// @dev Get the current status of an ERC721 order.
+    /// @param order The ERC721 order.
+    /// @return status The status of the order.
+    function getERC721OrderStatus(LibNFTOrder.ERC721Order _calldata_ order)
+        _external_
+        _view_
+        returns (LibNFTOrder.OrderStatus status);
+    
+
+getERC721OrderHash
+----------------------------
+
+A read function to return the uniquie order hash.
+
+.. code-block:: solidity
+
+    /// @dev Get the canonical hash of an ERC721 order.
+    /// @param order The ERC721 order.
+    /// @return orderHash The order hash.
+    function getERC721OrderHash(LibNFTOrder.ERC721Order _calldata_ order)
+        _external_
+        _view_
+        returns (bytes32 orderHash);
+    
+getERC721OrderStatusBitVector
+---------------------------------
+
+.. code-block:: solidity
+
+    /// @dev Get the order status bit vector for the given
+    ///      maker address and nonce range.
+    /// @param maker The maker of the order.
+    /// @param nonceRange Order status bit vectors are indexed
+    ///        by maker address and the upper 248 bits of the
+    ///        order nonce. We define `nonceRange` to be these
+    ///        248 bits.
+    /// @return bitVector The order status bit vector for the
+    ///         given maker and nonce range.
+    function getERC721OrderStatusBitVector(address maker, uint248 nonceRange)
+        _external_
+        _view_
+        returns (uint256 bitVector);
+
+sellERC1155
+----------------------------
+
+Sells an ERC115 token given a buy order. 
+
+.. code-block:: solidity
+
+    /// @dev Sells an ERC1155 asset to fill the given order.
+    /// @param buyOrder The ERC1155 buy order.
+    /// @param signature The order signature from the maker.
+    /// @param erc1155TokenId The ID of the ERC1155 asset being
+    ///        sold. If the given order specifies properties,
+    ///        the asset must satisfy those properties. Otherwise,
+    ///        it must equal the tokenId in the order.
+    /// @param erc1155SellAmount The amount of the ERC1155 asset
+    ///        to sell.
+    /// @param unwrapNativeToken If this parameter is true and the
+    ///        ERC20 token of the order is e.g. WETH, unwraps the
+    ///        token before transferring it to the taker.
+    /// @param callbackData If this parameter is non-zero, invokes
+    ///        `zeroExERC1155OrderCallback` on `msg.sender` after
+    ///        the ERC20 tokens have been transferred to `msg.sender`
+    ///        but before transferring the ERC1155 asset to the buyer.
+    function sellERC1155(
+        LibNFTOrder.ERC1155Order _calldata_ buyOrder,
+        LibSignature.Signature _calldata_ signature,
+        uint256 erc1155TokenId,
+        uint128 erc1155SellAmount,
+        bool unwrapNativeToken,
+        bytes _calldata_ callbackData
+    )
+        _external_;
+    
+
+buyERC1155
+----------------------------
+
+Buys an ERC115 token given a sell order. 
+
+.. code-block:: solidity
+
+    /// @dev Buys an ERC1155 asset by filling the given order.
+    /// @param sellOrder The ERC1155 sell order.
+    /// @param signature The order signature.
+    /// @param erc1155BuyAmount The amount of the ERC1155 asset
+    ///        to buy.
+    /// @param callbackData If this parameter is non-zero, invokes
+    ///        `zeroExERC1155OrderCallback` on `msg.sender` after
+    ///        the ERC1155 asset has been transferred to `msg.sender`
+    ///        but before transferring the ERC20 tokens to the seller.
+    ///        Native tokens acquired during the callback can be used
+    ///        to fill the order.
+    function buyERC1155(
+        LibNFTOrder.ERC1155Order _calldata_ sellOrder,
+        LibSignature.Signature _calldata_ signature,
+        uint128 erc1155BuyAmount,
+        bytes _calldata_ callbackData
+    )
+        _external_
+        _payable_;
+    
+
+cancelERC1155Order
+----------------------------
+
+Cancels an ERC115 order given the order struct. 
+
+.. code-block:: solidity
+
+    /// @dev Cancel a single ERC1155 order. The caller should be the
+    ///      maker of the order. Silently succeeds if the order has
+    ///      already been filled or cancelled.
+    /// @param order The order to cancel.
+    function cancelERC1155Order(LibNFTOrder.ERC1155Order _calldata_ order)
+        _external_;
+
+batchCancelERC1155Orders
+----------------------------
+
+Cancels a number of ERC115 orders. 
+
+.. code-block:: solidity
+
+    /// @dev Cancel multiple ERC1155 orders. The caller should be the
+    ///      maker of the orders. Silently succeeds if an order has
+    ///      already been filled or cancelled.
+    /// @param orders The orders to cancel.
+    function batchCancelERC1155Orders(LibNFTOrder.ERC1155Order[] _calldata_ orders)
+        _external_;
+    
+batchBuyERC1155s
+----------------------------
+
+Buys multiple ERC1155 assets given the sell orders.
+
+.. code-block:: solidity
+
+    /// @dev Buys multiple ERC1155 assets by filling the
+    ///      given orders.
+    /// @param sellOrders The ERC1155 sell orders.
+    /// @param signatures The order signatures.
+    /// @param erc1155TokenAmounts The amounts of the ERC1155 assets
+    ///        to buy for each order.
+    /// @param revertIfIncomplete If true, reverts if this
+    ///        function fails to fill any individual order.
+    /// @return successes An array of booleans corresponding to whether
+    ///         each order in `orders` was successfully filled.
+    function batchBuyERC1155s(
+        LibNFTOrder.ERC1155Order[] _calldata_ sellOrders,
+        LibSignature.Signature[] _calldata_ signatures,
+        uint128[] _calldata_ erc1155TokenAmounts,
+        bool revertIfIncomplete
+    )
+        _external_
+        _payable_
+        returns (bool[] _memory_ successes);
+    
+preSignERC1155Order
+----------------------------
+
+Pre-signs the order on-chain. This is useful for smart contracts.
+
+.. code-block:: solidity
+
+    /// @dev Approves an ERC1155 order on-chain. After pre-signing
+    ///      the order, the `PRESIGNED` signature type will become
+    ///      valid for that order and signer.
+    /// @param order An ERC1155 order.
+    function preSignERC1155Order(LibNFTOrder.ERC1155Order _calldata_ order)
+        _external_;
+
+
+validateERC1155OrderSignature
+---------------------------------
+
+A read function to validate the ERC1155 order signatures.
+
+.. code-block:: solidity
+
+    /// @dev Checks whether the given signature is valid for the
+    ///      the given ERC1155 order. Reverts if not.
+    /// @param order The ERC1155 order.
+    /// @param signature The signature to validate.
+    function validateERC1155OrderSignature(
+        LibNFTOrder.ERC1155Order calldata order,
+        LibSignature.Signature calldata signature
+    )
+        external
+        view;
+
+
+validateERC1155OrderProperties
+---------------------------------
+
+A read function to validate the specific ERC1155 asset against a property based order.
+
+.. code-block:: solidity
+
+    /// @dev If the given order is buying an ERC1155 asset, checks
+    ///      whether or not the given token ID satisfies the required
+    ///      properties specified in the order. If the order does not
+    ///      specify any properties, this function instead checks
+    ///      whether the given token ID matches the ID in the order.
+    ///      Reverts if any checks fail, or if the order is selling
+    ///      an ERC1155 asset.
+    /// @param order The ERC1155 order.
+    /// @param erc1155TokenId The ID of the ERC1155 asset.
+    function validateERC1155OrderProperties(
+        LibNFTOrder.ERC1155Order calldata order,
+        uint256 erc1155TokenId
+    )
+        external
+        view;
+
+getERC1155OrderInfo
+----------------------------
+
+A read function to get the ERC1155 order info. Such as whether it has been cancelled, expired or filled.
+
+.. code-block:: solidity
+
+    /// @dev Get the order info for an ERC1155 order.
+    /// @param order The ERC1155 order.
+    /// @return orderInfo Infor about the order.
+    function getERC1155OrderInfo(LibNFTOrder.ERC1155Order calldata order)
+        external
+        view
+        returns (LibNFTOrder.OrderInfo memory orderInfo);
+
+getERC1155OrderHash
+----------------------------
+
+A read function to calculate the unique order hash.
+
+.. code-block:: solidity
+
+    /// @dev Get the canonical hash of an ERC1155 order.
+    /// @param order The ERC1155 order.
+    /// @return orderHash The order hash.
+    function getERC1155OrderHash(LibNFTOrder.ERC1155Order calldata order)
+        external
+        view
+        returns (bytes32 orderHash);
--- a/docs/basics/orders.rst
+++ b/docs/basics/orders.rst
@@ -89,10 +89,160 @@ The ``RFQOrder`` struct has the following fields:
 +-----------------+-------------+----------------------------------------------------------------------------------------------------------------------------+


+NFT Orders
+===========
+
+NFT orders in 0x V4 are optimized for this specific use case. They are up to 54% cheaper than alternatives currently on Ethereum.
+Unlike 0x Limit orders, there is a `direction` of the trade, either buy or sell. ERC20's can be exchanged for either ERC721 or ERC1155.
+
+Property based orders can also be created by specifying the properties field in the respective order. 
+
+A number of fees can be embedded in the order.
+
+`NFT Swap SDK <https://docs.swapsdk.xyz/0x-v4>`__ is a friendly library that will help you easily create and consume NFT orders in 0x V4. You can find their `documentation here <https://docs.swapsdk.xyz/0x-v4>`__.
+
+
+ERC721 Orders
+*************
+
+The ``ERC721Order`` struct has the following fields:
+
+----------------------------+-----------------+------------------------------------------------------------------------------------------+
+| Field                      | Type            | Description                                                                              |
+----------------------------+-----------------+------------------------------------------------------------------------------------------+
+| ``direction``              | ``enum``        | The trade direction, either sell the NFT or buy the NFT                                  |
+----------------------------+-----------------+------------------------------------------------------------------------------------------+
+| ``maker``                  | ``address``     | The address of the maker, and signer, of this order. [required]                          |
+----------------------------+-----------------+------------------------------------------------------------------------------------------+
+| ``taker``                  | ``address``     | Allowed taker address. Set to zero to allow any taker. [optional; default 0]             |
+----------------------------+-----------------+------------------------------------------------------------------------------------------+
+| ``expiry``                 | ``uint256``     | The Unix timestamp in seconds when this order expires. [required]                        |
+----------------------------+-----------------+------------------------------------------------------------------------------------------+
+| ``nonce``                  | ``uint256``     | Number used to uniquiely represent this order. Used for cancellations. [required]        |
+----------------------------+-----------------+------------------------------------------------------------------------------------------+
+| ``erc20Token``             | ``address``     | The ERC20 token used to pay for the ERC721 token. [required]                             |
+----------------------------+-----------------+------------------------------------------------------------------------------------------+
+| ``erc20TokenAmount``       | ``uint256``     | The amount of erc20Token being sold. [required]                                          |
+----------------------------+-----------------+------------------------------------------------------------------------------------------+
+| ``fees``                   | ``Fees[]``      | An array of structs containing the fee data  [optional]                                  |
+----------------------------+-----------------+------------------------------------------------------------------------------------------+
+| ``erc721Token``            | ``address``     | The ERC721 token. [required]                                                             |
+----------------------------+-----------------+------------------------------------------------------------------------------------------+
+| ``erc721TokenId``          | ``uint256``     | The ERC721 token id. [required]                                                          |
+----------------------------+-----------------+------------------------------------------------------------------------------------------+
+| ``erc721TokenProperties``  | ``Property[]``  | Properties to validate for a property based order. [optional]                            |
+----------------------------+-----------------+------------------------------------------------------------------------------------------+
+
+ERC1155 Orders
+***************
+
+The ``ERC1155Order`` struct has the following fields:
+
+----------------------------+-----------------+------------------------------------------------------------------------------------------+
+| Field                      | Type            | Description                                                                              |
+----------------------------+-----------------+------------------------------------------------------------------------------------------+
+| ``direction``              | ``enum``        | The trade direction, either sell the NFT or buy the NFT                                  |
+----------------------------+-----------------+------------------------------------------------------------------------------------------+
+| ``maker``                  | ``address``     | The address of the maker, and signer, of this order. [required]                          |
+----------------------------+-----------------+------------------------------------------------------------------------------------------+
+| ``taker``                  | ``address``     | Allowed taker address. Set to zero to allow any taker. [optional; default 0]             |
+----------------------------+-----------------+------------------------------------------------------------------------------------------+
+| ``expiry``                 | ``uint256``     | The Unix timestamp in seconds when this order expires. [required]                        |
+----------------------------+-----------------+------------------------------------------------------------------------------------------+
+| ``nonce``                  | ``uint256``     | Number used to uniquiely represent this order. Used for cancellations. [required]        |
+----------------------------+-----------------+------------------------------------------------------------------------------------------+
+| ``erc20Token``             | ``address``     | The ERC20 token used to pay for the ERC721 token. [required]                             |
+----------------------------+-----------------+------------------------------------------------------------------------------------------+
+| ``erc20TokenAmount``       | ``uint256``     | The amount of erc20Token being sold. [required]                                          |
+----------------------------+-----------------+------------------------------------------------------------------------------------------+
+| ``fees``                   | ``Fees[]``      | An array of structs containing the fee data  [optional]                                  |
+----------------------------+-----------------+------------------------------------------------------------------------------------------+
+| ``erc1155Token``           | ``address``     | The ERC1155 token. [required]                                                            |
+----------------------------+-----------------+------------------------------------------------------------------------------------------+
+| ``erc1155TokenId``         | ``uint256``     | The ERC1155 token id. [required]                                                         |
+----------------------------+-----------------+------------------------------------------------------------------------------------------+
+| ``erc1155TokenProperties`` | ``Property[]``  | Properties to validate for a property based order. [optional]                            |
+----------------------------+-----------------+------------------------------------------------------------------------------------------+
+| ``erc1155TokenAmount``     | ``uin128``      | The ERC1155 amount. [required]                                                           |
+----------------------------+-----------------+------------------------------------------------------------------------------------------+
+
+NFT Order Property
+******************
+
+For Property based NFT orders, the properties have the following fields:
+
+----------------------------+-----------------+------------------------------------------------------------------------------------------+
+| Field                      | Type            | Description                                                                              |
+----------------------------+-----------------+------------------------------------------------------------------------------------------+
+| ``propertyValidator``      | ``address``     | The address of the contract which implements `IPropertyValidator`.                       |
+----------------------------+-----------------+------------------------------------------------------------------------------------------+
+| ``propertyData``           | ``bytes``       | The address of the maker, and signer, of this order.                                     |
+----------------------------+-----------------+------------------------------------------------------------------------------------------+
+
+The property validator contract must implement the following interface when Property based orders are used.
+
+.. code-block:: solidity
+
+    /// @dev Checks that the given ERC721/ERC1155 asset satisfies the properties encoded in `propertyData`.
+    ///      Should revert if the asset does not satisfy the specified properties.
+    /// @param tokenAddress The ERC721/ERC1155 token contract address.
+    /// @param tokenId The ERC721/ERC1155 tokenId of the asset to check.
+    /// @param propertyData Encoded properties or auxiliary data needed to perform the check.
+    function validateProperty(
+        address tokenAddress,
+        uint256 tokenId,
+        bytes calldata propertyData
+    )
+        external
+        view;
+
+NFT Order Fee
+**************
+
+For NFT orders with fees, the fees have the following fields:
+
+----------------------------+-----------------+------------------------------------------------------------------------------------------+
+| Field                      | Type            | Description                                                                              |
+----------------------------+-----------------+------------------------------------------------------------------------------------------+
+| ``receipient``             | ``address``     | The receipient of the fees.                                                              |
+----------------------------+-----------------+------------------------------------------------------------------------------------------+
+| ``amount``                 | ``uint256``     | The amount of fee to be paid to recipient.                                               |
+----------------------------+-----------------+------------------------------------------------------------------------------------------+
+| ``feeData``                | ``bytes``       | If provided the recipient (contract) will be called with this feeData [optional]         |
+----------------------------+-----------------+------------------------------------------------------------------------------------------+
+
+The contract must implement the following interface when the `feeData` is present.
+
+.. code-block:: solidity
+
+    interface IFeeRecipient {
+
+        /// @dev A callback function invoked in the ERC721Feature for each ERC721 
+        ///      order fee that get paid. Integrators can make use of this callback
+        ///      to implement arbitrary fee-handling logic, e.g. splitting the fee 
+        ///      between multiple parties. 
+        /// @param tokenAddress The address of the token in which the received fee is 
+        ///        denominated. `0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE` indicates 
+        ///        that the fee was paid in the native token (e.g. ETH).
+        /// @param amount The amount of the given token received.
+        /// @param feeData Arbitrary data encoded in the `Fee` used by this callback.
+        /// @return success The selector of this function (0x0190805e), 
+        ///         indicating that the callback succeeded.
+        function receiveFeeCallback(
+            address tokenAddress,
+            uint256 amount,
+            bytes calldata feeData
+        )
+            external
+            returns (bytes4 success);
+    }
+
+
+
 How To Sign
 ==============

-Both Limit & RFQ orders must be signed by the `maker` or a registered order signer (`registerAllowedOrderSigner <./functions.html#registerallowedrfqorigins>`_). This signature is needed to fill an order, see `Basic Functionality <./functions.html>`_.
+Orders must be signed by the `maker` or a registered order signer (`registerAllowedOrderSigner <./functions.html#registerallowedrfqorigins>`_). This signature is needed to fill an order, see `Basic Functionality <./functions.html>`_.

 The protocol accepts signatures defined by the following struct:

--- a/docs/conf.py
+++ b/docs/conf.py
@@ -60,9 +60,9 @@ copyright = u'2016, ZeroEx Inc'
 # built documents.
 #
 # The short X.Y version.
-version = '4.0'
+version = '4.1'
 # The full version, including alpha/beta/rc tags.
-release = '4.0'
+release = '4.1'

 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.
--- a/docs/scripts/generate_addresses.py
+++ b/docs/scripts/generate_addresses.py
@@ -12,7 +12,6 @@ sections = [
        "name": "Exchange V4",
        "contracts": [
            'exchangeProxy',
-            'exchangeProxyAllowanceTarget',
            'exchangeProxyFlashWallet',
            'exchangeProxyGovernor',
            'exchangeProxyLiquidityProviderSandbox',
@@ -50,18 +49,43 @@ sections = [
    }
 ]

-def printRow(contract, address):
-    etherscanLink = "%s/%s"%("https://etherscan.io/address/", address)
-    print("    %s, `%s <%s>`_"%(contract, address, etherscanLink)) 
+networks = {
+    '1': 'Ethereum',
+    '10': 'Optimism',
+    '56': 'Binance Smart Chain',
+    '137': 'Polygon',
+    '43114': 'Avalanche',
+    '250': 'Fantom',
+    '42220': 'Celo',
+}

-def printTable(contracts, addresses):
+etherscanByNetwork = {
+    '1': 'https://etherscan.io/address',
+    '10': 'https://optimistic.etherscan.io/address',
+    '56': 'https://bscscan.com/address',
+    '137': 'https://polygonscan.com/address',
+    '43114': 'https://snowtrace.io/address',
+    '250': 'https://ftmscan.com/address',
+    '42220': 'https://explorer.celo.org/address',
+}
+
+
+def getLinkableAddress(address, network):
+    etherscanLink = "%s/%s"%(etherscanByNetwork[network], address)
+    return "`%s <%s>`__"%(address, etherscanLink)
+
+def printRow(contract, address, network):
+    etherscanLink = "%s/%s"%(etherscanByNetwork[network], address)
+    print("    %s, %s"%(contract, getLinkableAddress(address, network)))
+
+def printTable(contracts, addresses, network):
    print(".. csv-table::\n")
    for contract in contracts:
-        if isinstance(addresses[contract], unicode):
-            printRow(contract, addresses[contract])
+        if isinstance(addresses[contract], str):
+            printRow(contract, addresses[contract], network)
        else:
            for contract,address in addresses[contract].items():
-                printRow(contract, address)
+                printRow(contract, address, network)
                

 print(
@@ -72,6 +96,8 @@ Addresses

 .. note::
    This page is auto-generated. See the `contract-addresses <https://github.com/0xProject/protocol/blob/development/packages/contract-addresses/addresses.json>`_ package for an exhaustive list of contracts across all networks.
+
+    The Exchange Proxy may have different addresses on various networks, see the `Exchange Proxy Addresses <./addresses.html#exchange-proxy-addresses>`__ table for an exhaustive list.
 '''
 )

@@ -79,6 +105,13 @@ with open('../packages/contract-addresses/addresses.json') as f:
    addresses = json.load(f)
    for section in sections:
        print("%s\n==================="%(section["name"]))
-        printTable(section["contracts"], addresses["1"])
+        printTable(section["contracts"], addresses["1"], "1")
        print("\n\n")
+    print("Exchange Proxy Addresses \n=========================")
+    print("Note: Some addresses have changed across various networks\n")
+    print(".. csv-table::\n")
+    for network in networks:
+        # etherscanLink = "%s/%s"%("https://etherscan.io/address/", address)
+        # print("    %s, `%s <%s>`_"%(contract, address, etherscanLink)) 
+        print("    %s, %s"%(networks[network], getLinkableAddress(addresses[network]["exchangeProxy"], network))) 

--- a/package.json
+++ b/package.json
@@ -46,7 +46,7 @@
        "test:generate_docs:circleci": "for i in ${npm_package_config_packagesWithDocPages}; do yarn generate_doc --package $i || break -1; done;",
        "bundlewatch": "bundlewatch",
        "lint": "wsrun --fast-exit --parallel --exclude-missing -p $PKG -c lint",
-        "upgrade_org_deps": "node node_modules/@0x/monorepo-scripts/lib/upgrade_deps.js -p '@0x/|ethereum-types'",
+        "upgrade_tools": "node node_modules/@0x/monorepo-scripts/lib/upgrade_deps.js -p '@0x/abi-gen|@0x/assert|@0x/base-contract|@0x/contracts-gen|@0x/dev-utils|@0x/json-schemas|@0x/monorepo-scripts|@0x/sol-compiler|@0x/sol-coverage|@0x/sol-doc|@0x/sol-profiler|@0x/sol-resolver|@0x/sol-trace|@0x/sol-tracing-utils|@0x/subproviders|@0x/tslint-config|@0x/types|@0x/typescript-typings|@0x/utils|@0x/verdaccio|@0x/web3-wrapper|ethereum-types'",
        "upgrade_deps": "node node_modules/@0x/monorepo-scripts/lib/upgrade_deps.js",
        "verdaccio": "docker run --rm -i -p 4873:4873 0xorg/verdaccio"
    },
@@ -60,7 +60,7 @@
        "ignoreDependencyVersionsForPackage": "contract-wrappers"
    },
    "devDependencies": {
-        "@0x/monorepo-scripts": "^3.2.0",
+        "@0x/monorepo-scripts": "^3.2.2",
        "@0x-lerna-fork/lerna": "3.16.10",
        "@0xproject/npm-cli-login": "^0.0.11",
        "async-child-process": "^1.1.1",
--- a/packages/asset-swapper/CHANGELOG.json
+++ b/packages/asset-swapper/CHANGELOG.json
@@ -1,4 +1,95 @@
 [
+    {
+        "version": "16.49.9",
+        "changes": [
+            {
+                "note": "Fix native order scaling & filter out 1 wei quotes",
+                "pr": "430"
+            }
+        ],
+        "timestamp": 1645696356
+    },
+    {
+        "timestamp": 1645569128,
+        "version": "16.49.8",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "version": "16.49.7",
+        "changes": [
+            {
+                "note": "Fix native order handling for very small quotes and bump `neon-router` dependency",
+                "pr": 425
+            }
+        ],
+        "timestamp": 1645534245
+    },
+    {
+        "version": "16.49.6",
+        "changes": [
+            {
+                "note": "Fixed btrfly routing to include the ohmV2/dai, ohmV2/btfly, and ohmV2/weth pools",
+                "pr": 427
+            }
+        ],
+        "timestamp": 1645113751
+    },
+    {
+        "version": "16.49.5",
+        "changes": [
+            {
+                "note": "Fix scaling 1 base unit to 0, round output to base units",
+                "pr": 422
+            }
+        ],
+        "timestamp": 1644844353
+    },
+    {
+        "version": "16.49.4",
+        "changes": [
+            {
+                "note": "Reverts 'Improve Uniswap V3 gas schedule' due to issue with buys",
+                "pr": 419
+            }
+        ],
+        "timestamp": 1644507275
+    },
+    {
+        "version": "16.49.3",
+        "changes": [
+            {
+                "note": "Fix `slippage` inconsistency when recalculated in exchange proxy quote consumer",
+                "pr": 412
+            },
+            {
+                "note": "Fix incorrect output scaling when input is less than desired amount, update fast-abi",
+                "pr": 401
+            },
+            {
+                "note": "Improve Uniswap V3 gas schedule",
+                "pr": 397
+            },
+            {
+                "note": "Fix add Native as VIP and use Path to compare all sources vs vip only",
+                "pr": 413
+            }
+        ],
+        "timestamp": 1644495123
+    },
+    {
+        "version": "16.49.2",
+        "changes": [
+            {
+                "note": "Fix ABI encoding error with two hop buys due to applying slippage to uint(-1) values",
+                "pr": 410
+            }
+        ],
+        "timestamp": 1643653482
+    },
    {
        "version": "16.49.1",
        "changes": [
--- a/packages/asset-swapper/CHANGELOG.md
+++ b/packages/asset-swapper/CHANGELOG.md
@@ -5,6 +5,41 @@ Edit the package's CHANGELOG.json file only.

 CHANGELOG

+## v16.49.9 - _February 24, 2022_
+
+    * Fix native order scaling & filter out 1 wei quotes (#430)
+
+## v16.49.8 - _February 22, 2022_
+
+    * Dependencies updated
+
+## v16.49.7 - _February 22, 2022_
+
+    * Fix native order handling for very small quotes and bump `neon-router` dependency (#425)
+
+## v16.49.6 - _February 17, 2022_
+
+    * Fixed btrfly routing to include the ohmV2/dai, ohmV2/btfly, and ohmV2/weth pools (#427)
+
+## v16.49.5 - _February 14, 2022_
+
+    * Fix scaling 1 base unit to 0, round output to base units (#422)
+
+## v16.49.4 - _February 10, 2022_
+
+    * Reverts 'Improve Uniswap V3 gas schedule' due to issue with buys (#419)
+
+## v16.49.3 - _February 10, 2022_
+
+    * Fix `slippage` inconsistency when recalculated in exchange proxy quote consumer (#412)
+    * Fix incorrect output scaling when input is less than desired amount, update fast-abi (#401)
+    * Improve Uniswap V3 gas schedule (#397)
+    * Fix add Native as VIP and use Path to compare all sources vs vip only (#413)
+
+## v16.49.2 - _January 31, 2022_
+
+    * Fix ABI encoding error with two hop buys due to applying slippage to uint(-1) values (#410)
+
 ## v16.49.1 - _January 31, 2022_

    * Fix WorstCaseQuoteInfo encoding bug (#402)
--- a/packages/asset-swapper/contracts/src/ApproximateBuys.sol
+++ b/packages/asset-swapper/contracts/src/ApproximateBuys.sol
@@ -1,148 +0,0 @@
-// SPDX-License-Identifier: Apache-2.0
-/*
-
-  Copyright 2020 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 ^0.6;
-pragma experimental ABIEncoderV2;
-
-import "@0x/contracts-utils/contracts/src/v06/LibMathV06.sol";
-
-
-contract ApproximateBuys {
-
-    /// @dev Information computing buy quotes for sources that do not have native
-    ///      buy quote support.
-    struct ApproximateBuyQuoteOpts {
-        // Arbitrary maker token data to pass to `getSellQuoteCallback`.
-        bytes makerTokenData;
-        // Arbitrary taker token data to pass to `getSellQuoteCallback`.
-        bytes takerTokenData;
-        // Callback to retrieve a sell quote.
-        function (bytes memory, bytes memory, uint256)
-            internal
-            view
-            returns (uint256) getSellQuoteCallback;
-    }
-
-    uint256 private constant ONE_HUNDED_PERCENT_BPS = 1e4;
-    /// @dev Maximum approximate (positive) error rate when approximating a buy quote.
-    uint256 private constant APPROXIMATE_BUY_TARGET_EPSILON_BPS = 0.0005e4;
-    /// @dev Maximum iterations to perform when approximating a buy quote.
-    uint256 private constant APPROXIMATE_BUY_MAX_ITERATIONS = 5;
-
-    function _sampleApproximateBuys(
-        ApproximateBuyQuoteOpts memory opts,
-        uint256[] memory makerTokenAmounts
-    )
-        internal
-        view
-        returns (uint256[] memory takerTokenAmounts)
-    {
-        takerTokenAmounts = new uint256[](makerTokenAmounts.length);
-        if (makerTokenAmounts.length == 0) {
-            return takerTokenAmounts;
-        }
-
-        uint256 sellAmount = opts.getSellQuoteCallback(
-            opts.makerTokenData,
-            opts.takerTokenData,
-            makerTokenAmounts[0]
-        );
-        if (sellAmount == 0) {
-            return takerTokenAmounts;
-        }
-
-        uint256 buyAmount = opts.getSellQuoteCallback(
-            opts.takerTokenData,
-            opts.makerTokenData,
-            sellAmount
-        );
-        if (buyAmount == 0) {
-            return takerTokenAmounts;
-        }
-
-        for (uint256 i = 0; i < makerTokenAmounts.length; i++) {
-            uint256 eps = 0;
-            for (uint256 iter = 0; iter < APPROXIMATE_BUY_MAX_ITERATIONS; iter++) {
-                // adjustedSellAmount = previousSellAmount * (target/actual) * JUMP_MULTIPLIER
-                sellAmount = _safeGetPartialAmountCeil(
-                    makerTokenAmounts[i],
-                    buyAmount,
-                    sellAmount
-                );
-                if (sellAmount == 0) {
-                    break;
-                }
-                sellAmount = _safeGetPartialAmountCeil(
-                    (ONE_HUNDED_PERCENT_BPS + APPROXIMATE_BUY_TARGET_EPSILON_BPS),
-                    ONE_HUNDED_PERCENT_BPS,
-                    sellAmount
-                );
-                if (sellAmount == 0) {
-                    break;
-                }
-                uint256 _buyAmount = opts.getSellQuoteCallback(
-                    opts.takerTokenData,
-                    opts.makerTokenData,
-                    sellAmount
-                );
-                if (_buyAmount == 0) {
-                    break;
-                }
-                // We re-use buyAmount next iteration, only assign if it is
-                // non zero
-                buyAmount = _buyAmount;
-                // If we've reached our goal, exit early
-                if (buyAmount >= makerTokenAmounts[i]) {
-                    eps =
-                        (buyAmount - makerTokenAmounts[i]) * ONE_HUNDED_PERCENT_BPS /
-                        makerTokenAmounts[i];
-                    if (eps <= APPROXIMATE_BUY_TARGET_EPSILON_BPS) {
-                        break;
-                    }
-                }
-            }
-            if (eps == 0 || eps > APPROXIMATE_BUY_TARGET_EPSILON_BPS) {
-                break;
-            }
-            // We do our best to close in on the requested amount, but we can either over buy or under buy and exit
-            // if we hit a max iteration limit
-            // We scale the sell amount to get the approximate target
-            takerTokenAmounts[i] = _safeGetPartialAmountCeil(
-                makerTokenAmounts[i],
-                buyAmount,
-                sellAmount
-            );
-        }
-    }
-
-    function _safeGetPartialAmountCeil(
-        uint256 numerator,
-        uint256 denominator,
-        uint256 target
-    )
-        internal
-        view
-        returns (uint256 partialAmount)
-    {
-        if (numerator == 0 || target == 0 || denominator == 0) return 0;
-        uint256 c = numerator * target;
-        if (c / numerator != target) return 0;
-        return (c + (denominator - 1)) / denominator;
-    }
-}
--- a/packages/asset-swapper/contracts/src/BalancerSampler.sol
+++ b/packages/asset-swapper/contracts/src/BalancerSampler.sol
@@ -1,197 +0,0 @@
-// SPDX-License-Identifier: Apache-2.0
-/*
-
-  Copyright 2020 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 ^0.6;
-pragma experimental ABIEncoderV2;
-
-import "./interfaces/IBalancer.sol";
-
-
-contract BalancerSampler {
-
-    /// @dev Base gas limit for Balancer calls.
-    uint256 constant private BALANCER_CALL_GAS = 300e3; // 300k
-
-    // Balancer math constants
-    // https://github.com/balancer-labs/balancer-core/blob/master/contracts/BConst.sol
-    uint256 constant private BONE = 10 ** 18;
-    uint256 constant private MAX_IN_RATIO = BONE / 2;
-    uint256 constant private MAX_OUT_RATIO = (BONE / 3) + 1 wei;
-
-    struct BalancerState {
-        uint256 takerTokenBalance;
-        uint256 makerTokenBalance;
-        uint256 takerTokenWeight;
-        uint256 makerTokenWeight;
-        uint256 swapFee;
-    }
-
-    /// @dev Sample sell quotes from Balancer.
-    /// @param poolAddress Address of the Balancer pool to query.
-    /// @param takerToken Address of the taker token (what to sell).
-    /// @param makerToken Address of the maker token (what to buy).
-    /// @param takerTokenAmounts Taker token sell amount for each sample.
-    /// @return makerTokenAmounts Maker amounts bought at each taker token
-    ///         amount.
-    function sampleSellsFromBalancer(
-        address poolAddress,
-        address takerToken,
-        address makerToken,
-        uint256[] memory takerTokenAmounts
-    )
-        public
-        view
-        returns (uint256[] memory makerTokenAmounts)
-    {
-        IBalancer pool = IBalancer(poolAddress);
-        uint256 numSamples = takerTokenAmounts.length;
-        makerTokenAmounts = new uint256[](numSamples);
-        if (!pool.isBound(takerToken) || !pool.isBound(makerToken)) {
-            return makerTokenAmounts;
-        }
-
-        BalancerState memory poolState;
-        poolState.takerTokenBalance = pool.getBalance(takerToken);
-        poolState.makerTokenBalance = pool.getBalance(makerToken);
-        poolState.takerTokenWeight = pool.getDenormalizedWeight(takerToken);
-        poolState.makerTokenWeight = pool.getDenormalizedWeight(makerToken);
-        poolState.swapFee = pool.getSwapFee();
-
-        for (uint256 i = 0; i < numSamples; i++) {
-            // Handles this revert scenario:
-            // https://github.com/balancer-labs/balancer-core/blob/master/contracts/BPool.sol#L443
-            if (takerTokenAmounts[i] > _bmul(poolState.takerTokenBalance, MAX_IN_RATIO)) {
-                break;
-            }
-            try
-                pool.calcOutGivenIn
-                    {gas: BALANCER_CALL_GAS}
-                    (
-                        poolState.takerTokenBalance,
-                        poolState.takerTokenWeight,
-                        poolState.makerTokenBalance,
-                        poolState.makerTokenWeight,
-                        takerTokenAmounts[i],
-                        poolState.swapFee
-                    )
-                returns (uint256 amount)
-            {
-                makerTokenAmounts[i] = amount;
-                // Break early if there are 0 amounts
-                if (makerTokenAmounts[i] == 0) {
-                    break;
-                }
-            } catch (bytes memory) {
-                // Swallow failures, leaving all results as zero.
-                break;
-            }
-        }
-    }
-
-    /// @dev Sample buy quotes from Balancer.
-    /// @param poolAddress Address of the Balancer pool to query.
-    /// @param takerToken Address of the taker token (what to sell).
-    /// @param makerToken Address of the maker token (what to buy).
-    /// @param makerTokenAmounts Maker token buy amount for each sample.
-    /// @return takerTokenAmounts Taker amounts sold at each maker token
-    ///         amount.
-    function sampleBuysFromBalancer(
-        address poolAddress,
-        address takerToken,
-        address makerToken,
-        uint256[] memory makerTokenAmounts
-    )
-        public
-        view
-        returns (uint256[] memory takerTokenAmounts)
-    {
-        IBalancer pool = IBalancer(poolAddress);
-        uint256 numSamples = makerTokenAmounts.length;
-        takerTokenAmounts = new uint256[](numSamples);
-        if (!pool.isBound(takerToken) || !pool.isBound(makerToken)) {
-            return takerTokenAmounts;
-        }
-
-        BalancerState memory poolState;
-        poolState.takerTokenBalance = pool.getBalance(takerToken);
-        poolState.makerTokenBalance = pool.getBalance(makerToken);
-        poolState.takerTokenWeight = pool.getDenormalizedWeight(takerToken);
-        poolState.makerTokenWeight = pool.getDenormalizedWeight(makerToken);
-        poolState.swapFee = pool.getSwapFee();
-
-        for (uint256 i = 0; i < numSamples; i++) {
-            // Handles this revert scenario:
-            // https://github.com/balancer-labs/balancer-core/blob/master/contracts/BPool.sol#L505
-            if (makerTokenAmounts[i] > _bmul(poolState.makerTokenBalance, MAX_OUT_RATIO)) {
-                break;
-            }
-            try
-                pool.calcInGivenOut
-                    {gas: BALANCER_CALL_GAS}
-                    (
-                        poolState.takerTokenBalance,
-                        poolState.takerTokenWeight,
-                        poolState.makerTokenBalance,
-                        poolState.makerTokenWeight,
-                        makerTokenAmounts[i],
-                        poolState.swapFee
-                    )
-                returns (uint256 amount)
-            {
-                // Handles this revert scenario:
-                // https://github.com/balancer-labs/balancer-core/blob/master/contracts/BPool.sol#L443
-                if (amount > _bmul(poolState.takerTokenBalance, MAX_IN_RATIO)) {
-                    break;
-                }
-
-                takerTokenAmounts[i] = amount;
-                // Break early if there are 0 amounts
-                if (takerTokenAmounts[i] == 0) {
-                    break;
-                }
-            } catch (bytes memory) {
-                // Swallow failures, leaving all results as zero.
-                break;
-            }
-        }
-    }
-
-    /// @dev Hacked version of Balancer's `bmul` function, returning 0 instead
-    ///      of reverting.
-    ///      https://github.com/balancer-labs/balancer-core/blob/master/contracts/BNum.sol#L63-L73
-    /// @param a The first operand.
-    /// @param b The second operand.
-    /// @param c The result of the multiplication, or 0 if `bmul` would've reverted.
-    function _bmul(uint256 a, uint256 b)
-        private
-        pure
-        returns (uint256 c)
-    {
-        uint c0 = a * b;
-        if (a != 0 && c0 / a != b) {
-            return 0;
-        }
-        uint c1 = c0 + (BONE / 2);
-        if (c1 < c0) {
-            return 0;
-        }
-        uint c2 = c1 / BONE;
-        return c2;
-    }
-}
--- a/packages/asset-swapper/contracts/src/BalancerV2Sampler.sol
+++ b/packages/asset-swapper/contracts/src/BalancerV2Sampler.sol
@@ -1,189 +0,0 @@
-// SPDX-License-Identifier: Apache-2.0
-/*
-
-  Copyright 2021 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 ^0.6;
-pragma experimental ABIEncoderV2;
-
-import "./SamplerUtils.sol";
-
-/// @dev Minimal Balancer V2 Vault interface
-///      for documentation refer to https://github.com/balancer-labs/balancer-core-v2/blob/master/contracts/vault/interfaces/IVault.sol
-interface IBalancerV2Vault {
-    enum SwapKind { GIVEN_IN, GIVEN_OUT }
-
-    struct BatchSwapStep {
-        bytes32 poolId;
-        uint256 assetInIndex;
-        uint256 assetOutIndex;
-        uint256 amount;
-        bytes userData;
-    }
-
-    struct FundManagement {
-        address sender;
-        bool fromInternalBalance;
-        address payable recipient;
-        bool toInternalBalance;
-    }
-
-    function queryBatchSwap(
-        SwapKind kind,
-        BatchSwapStep[] calldata swaps,
-        IAsset[] calldata assets,
-        FundManagement calldata funds
-    ) external returns (int256[] memory assetDeltas);
-}
-interface IAsset {
-    // solhint-disable-previous-line no-empty-blocks
-}
-
-contract BalancerV2Sampler is SamplerUtils {
-
-    struct BalancerV2PoolInfo {
-        bytes32 poolId;
-        address vault;
-    }
-
-    /// @dev Sample sell quotes from Balancer V2.
-    /// @param poolInfo Struct with pool related data
-    /// @param takerToken Address of the taker token (what to sell).
-    /// @param makerToken Address of the maker token (what to buy).
-    /// @param takerTokenAmounts Taker token sell amount for each sample.
-    /// @return makerTokenAmounts Maker amounts bought at each taker token
-    ///         amount.
-    function sampleSellsFromBalancerV2(
-        BalancerV2PoolInfo memory poolInfo,
-        address takerToken,
-        address makerToken,
-        uint256[] memory takerTokenAmounts
-    )
-        public
-        returns (uint256[] memory makerTokenAmounts)
-    {
-        _assertValidPair(makerToken, takerToken);
-        IBalancerV2Vault vault = IBalancerV2Vault(poolInfo.vault);
-        IAsset[] memory swapAssets = new IAsset[](2);
-        swapAssets[0] = IAsset(takerToken);
-        swapAssets[1] = IAsset(makerToken);
-
-        uint256 numSamples = takerTokenAmounts.length;
-        makerTokenAmounts = new uint256[](numSamples);
-        IBalancerV2Vault.FundManagement memory swapFunds =
-            _createSwapFunds();
-
-        for (uint256 i = 0; i < numSamples; i++) {
-            IBalancerV2Vault.BatchSwapStep[] memory swapSteps =
-                _createSwapSteps(poolInfo, takerTokenAmounts[i]);
-
-            try
-                // For sells we specify the takerToken which is what the vault will receive from the trade
-                vault.queryBatchSwap(IBalancerV2Vault.SwapKind.GIVEN_IN, swapSteps, swapAssets, swapFunds)
-            // amounts represent pool balance deltas from the swap (incoming balance, outgoing balance)
-            returns (int256[] memory amounts) {
-                // Outgoing balance is negative so we need to flip the sign
-                int256 amountOutFromPool = amounts[1] * -1;
-                if (amountOutFromPool <= 0) {
-                    break;
-                }
-                makerTokenAmounts[i] = uint256(amountOutFromPool);
-            } catch (bytes memory) {
-                // Swallow failures, leaving all results as zero.
-                break;
-            }
-        }
-    }
-
-    /// @dev Sample buy quotes from Balancer V2.
-    /// @param poolInfo Struct with pool related data
-    /// @param takerToken Address of the taker token (what to sell).
-    /// @param makerToken Address of the maker token (what to buy).
-    /// @param makerTokenAmounts Maker token buy amount for each sample.
-    /// @return takerTokenAmounts Taker amounts sold at each maker token
-    ///         amount.
-    function sampleBuysFromBalancerV2(
-        BalancerV2PoolInfo memory poolInfo,
-        address takerToken,
-        address makerToken,
-        uint256[] memory makerTokenAmounts
-    )
-        public
-        returns (uint256[] memory takerTokenAmounts)
-    {
-        _assertValidPair(makerToken, takerToken);
-        IBalancerV2Vault vault = IBalancerV2Vault(poolInfo.vault);
-        IAsset[] memory swapAssets = new IAsset[](2);
-        swapAssets[0] = IAsset(takerToken);
-        swapAssets[1] = IAsset(makerToken);
-
-        uint256 numSamples = makerTokenAmounts.length;
-        takerTokenAmounts = new uint256[](numSamples);
-        IBalancerV2Vault.FundManagement memory swapFunds =
-            _createSwapFunds();
-
-        for (uint256 i = 0; i < numSamples; i++) {
-            IBalancerV2Vault.BatchSwapStep[] memory swapSteps =
-                _createSwapSteps(poolInfo, makerTokenAmounts[i]);
-
-            try
-                // For buys we specify the makerToken which is what taker will receive from the trade
-                vault.queryBatchSwap(IBalancerV2Vault.SwapKind.GIVEN_OUT, swapSteps, swapAssets, swapFunds)
-            returns (int256[] memory amounts) {
-                int256 amountIntoPool = amounts[0];
-                if (amountIntoPool <= 0) {
-                    break;
-                }
-                takerTokenAmounts[i] = uint256(amountIntoPool);
-            } catch (bytes memory) {
-                // Swallow failures, leaving all results as zero.
-                break;
-            }
-        }
-    }
-
-    function _createSwapSteps(
-        BalancerV2PoolInfo memory poolInfo,
-        uint256 amount
-    ) private pure returns (IBalancerV2Vault.BatchSwapStep[] memory) {
-        IBalancerV2Vault.BatchSwapStep[] memory swapSteps =
-            new IBalancerV2Vault.BatchSwapStep[](1);
-        swapSteps[0] = IBalancerV2Vault.BatchSwapStep({
-            poolId: poolInfo.poolId,
-            assetInIndex: 0,
-            assetOutIndex: 1,
-            amount: amount,
-            userData: ""
-        });
-
-        return swapSteps;
-    }
-
-    function _createSwapFunds()
-        private
-        view
-        returns (IBalancerV2Vault.FundManagement memory)
-    {
-        return
-            IBalancerV2Vault.FundManagement({
-                sender: address(this),
-                fromInternalBalance: false,
-                recipient: payable(address(this)),
-                toInternalBalance: false
-            });
-    }
-}
--- a/packages/asset-swapper/contracts/src/BancorSampler.sol
+++ b/packages/asset-swapper/contracts/src/BancorSampler.sol
@@ -1,142 +0,0 @@
-// SPDX-License-Identifier: Apache-2.0
-/*
-
-  Copyright 2020 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 ^0.6;
-pragma experimental ABIEncoderV2;
-
-import "./interfaces/IBancor.sol";
-
-contract CompilerHack {}
-
-contract BancorSampler is CompilerHack {
-
-    /// @dev Base gas limit for Bancor calls.
-    uint256 constant private BANCOR_CALL_GAS = 300e3; // 300k
-
-    struct BancorSamplerOpts {
-        IBancorRegistry registry;
-        address[][] paths;
-    }
-
-    /// @dev Sample sell quotes from Bancor.
-    /// @param opts BancorSamplerOpts The Bancor registry contract address and paths
-    /// @param takerToken Address of the taker token (what to sell).
-    /// @param makerToken Address of the maker token (what to buy).
-    /// @param takerTokenAmounts Taker token sell amount for each sample.
-    /// @return bancorNetwork the Bancor Network address
-    /// @return path the selected conversion path from bancor
-    /// @return makerTokenAmounts Maker amounts bought at each taker token
-    ///         amount.
-    function sampleSellsFromBancor(
-        BancorSamplerOpts memory opts,
-        address takerToken,
-        address makerToken,
-        uint256[] memory takerTokenAmounts
-    )
-        public
-        view
-        returns (address bancorNetwork, address[] memory path, uint256[] memory makerTokenAmounts)
-    {
-        if (opts.paths.length == 0) {
-            return (bancorNetwork, path, makerTokenAmounts);
-        }
-        (bancorNetwork, path) = _findBestPath(opts, takerToken, makerToken, takerTokenAmounts);
-        makerTokenAmounts = new uint256[](takerTokenAmounts.length);
-
-        for (uint256 i = 0; i < makerTokenAmounts.length; i++) {
-            try
-                IBancorNetwork(bancorNetwork)
-                    .rateByPath
-                        {gas: BANCOR_CALL_GAS}
-                        (path, takerTokenAmounts[i])
-                returns (uint256 amount)
-            {
-                makerTokenAmounts[i] = amount;
-                // Break early if there are 0 amounts
-                if (makerTokenAmounts[i] == 0) {
-                    break;
-                }
-            } catch {
-                // Swallow failures, leaving all results as zero.
-                break;
-            }
-        }
-        return (bancorNetwork, path, makerTokenAmounts);
-    }
-
-    /// @dev Sample buy quotes from Bancor. Unimplemented
-    /// @param opts BancorSamplerOpts The Bancor registry contract address and paths
-    /// @param takerToken Address of the taker token (what to sell).
-    /// @param makerToken Address of the maker token (what to buy).
-    /// @param makerTokenAmounts Maker token buy amount for each sample.
-    /// @return bancorNetwork the Bancor Network address
-    /// @return path the selected conversion path from bancor
-    /// @return takerTokenAmounts Taker amounts sold at each maker token
-    ///         amount.
-    function sampleBuysFromBancor(
-        BancorSamplerOpts memory opts,
-        address takerToken,
-        address makerToken,
-        uint256[] memory makerTokenAmounts
-    )
-        public
-        view
-        returns (address bancorNetwork, address[] memory path, uint256[] memory takerTokenAmounts)
-    {
-    }
-
-    function _findBestPath(
-        BancorSamplerOpts memory opts,
-        address takerToken,
-        address makerToken,
-        uint256[] memory takerTokenAmounts
-    )
-        internal
-        view
-        returns (address bancorNetwork, address[] memory path)
-    {
-        bancorNetwork = opts.registry.getAddress(opts.registry.BANCOR_NETWORK());
-        if (opts.paths.length == 0) {
-            return (bancorNetwork, path);
-        }
-        uint256 maxBoughtAmount = 0;
-        // Find the best path by selling the largest taker amount
-        for (uint256 i = 0; i < opts.paths.length; i++) {
-            if (opts.paths[i].length < 2) {
-                continue;
-            }
-
-            try
-                IBancorNetwork(bancorNetwork)
-                    .rateByPath
-                        {gas: BANCOR_CALL_GAS}
-                        (opts.paths[i], takerTokenAmounts[takerTokenAmounts.length-1])
-                returns (uint256 amount)
-            {
-                if (amount > maxBoughtAmount) {
-                    maxBoughtAmount = amount;
-                    path = opts.paths[i];
-                }
-            } catch {
-                // Swallow failures, leaving all results as zero.
-                continue;
-            }
-        }
-    }
-}
--- a/packages/asset-swapper/contracts/src/CompoundSampler.sol
+++ b/packages/asset-swapper/contracts/src/CompoundSampler.sol
@@ -1,96 +0,0 @@
-// SPDX-License-Identifier: Apache-2.0
-/*
-
-  Copyright 2021 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 ^0.6;
-pragma experimental ABIEncoderV2;
-
-import "./SamplerUtils.sol";
-import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
-
-// Minimal CToken interface
-interface ICToken {
-    function mint(uint mintAmount) external returns (uint);
-    function redeem(uint redeemTokens) external returns (uint);
-    function redeemUnderlying(uint redeemAmount) external returns (uint);
-    function exchangeRateStored() external view returns (uint);
-    function decimals() external view returns (uint8);
-}
-
-contract CompoundSampler is SamplerUtils {
-    uint256 constant private EXCHANGE_RATE_SCALE = 1e10;
-
-    function sampleSellsFromCompound(
-        ICToken cToken,
-        IERC20TokenV06 takerToken,
-        IERC20TokenV06 makerToken,
-        uint256[] memory takerTokenAmounts
-    )
-        public
-        view
-        returns (uint256[] memory makerTokenAmounts)
-    {
-        uint256 numSamples = takerTokenAmounts.length;
-        makerTokenAmounts = new uint256[](numSamples);
-        // Exchange rate is scaled by 1 * 10^(18 - 8 + Underlying Token Decimals
-        uint256 exchangeRate = cToken.exchangeRateStored();
-        uint256 cTokenDecimals = uint256(cToken.decimals());
-
-        if (address(makerToken) == address(cToken)) {
-            // mint
-            for (uint256 i = 0; i < numSamples; i++) {
-                makerTokenAmounts[i] = (takerTokenAmounts[i] * EXCHANGE_RATE_SCALE * 10 ** cTokenDecimals) / exchangeRate;
-            }
-
-        } else if (address(takerToken) == address(cToken)) {
-            // redeem
-            for (uint256 i = 0; i < numSamples; i++) {
-                makerTokenAmounts[i] = (takerTokenAmounts[i] * exchangeRate) / (EXCHANGE_RATE_SCALE * 10 ** cTokenDecimals);
-            }
-        }
-    }
-
-    function sampleBuysFromCompound(
-        ICToken cToken,
-        IERC20TokenV06 takerToken,
-        IERC20TokenV06 makerToken,
-        uint256[] memory makerTokenAmounts
-    )
-        public
-        view
-        returns (uint256[] memory takerTokenAmounts)
-    {
-        uint256 numSamples = makerTokenAmounts.length;
-        takerTokenAmounts = new uint256[](numSamples);
-        // Exchange rate is scaled by 1 * 10^(18 - 8 + Underlying Token Decimals
-        uint256 exchangeRate = cToken.exchangeRateStored();
-        uint256 cTokenDecimals = uint256(cToken.decimals());
-
-        if (address(makerToken) == address(cToken)) {
-            // mint
-            for (uint256 i = 0; i < numSamples; i++) {
-                takerTokenAmounts[i] = makerTokenAmounts[i] * exchangeRate / (EXCHANGE_RATE_SCALE * 10 ** cTokenDecimals);
-            }
-        } else if (address(takerToken) == address(cToken)) {
-            // redeem
-            for (uint256 i = 0; i < numSamples; i++) {
-                takerTokenAmounts[i] = (makerTokenAmounts[i] * EXCHANGE_RATE_SCALE * 10 ** cTokenDecimals)/exchangeRate;
-            }
-        }
-    }
-}
--- a/packages/asset-swapper/contracts/src/CurveSampler.sol
+++ b/packages/asset-swapper/contracts/src/CurveSampler.sol
@@ -1,161 +0,0 @@
-// SPDX-License-Identifier: Apache-2.0
-/*
-
-  Copyright 2020 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 ^0.6;
-pragma experimental ABIEncoderV2;
-
-import "./interfaces/ICurve.sol";
-import "./ApproximateBuys.sol";
-import "./SamplerUtils.sol";
-
-
-contract CurveSampler is
-    SamplerUtils,
-    ApproximateBuys
-{
-    /// @dev Information for sampling from curve sources.
-    struct CurveInfo {
-        address poolAddress;
-        bytes4 sellQuoteFunctionSelector;
-        bytes4 buyQuoteFunctionSelector;
-    }
-
-    /// @dev Base gas limit for Curve calls. Some Curves have multiple tokens
-    ///      So a reasonable ceil is 150k per token. Biggest Curve has 4 tokens.
-    uint256 constant private CURVE_CALL_GAS = 2000e3; // Was 600k for Curve but SnowSwap is using 1500k+
-
-    /// @dev Sample sell quotes from Curve.
-    /// @param curveInfo Curve information specific to this token pair.
-    /// @param fromTokenIdx Index of the taker token (what to sell).
-    /// @param toTokenIdx Index of the maker token (what to buy).
-    /// @param takerTokenAmounts Taker token sell amount for each sample.
-    /// @return makerTokenAmounts Maker amounts bought at each taker token
-    ///         amount.
-    function sampleSellsFromCurve(
-        CurveInfo memory curveInfo,
-        int128 fromTokenIdx,
-        int128 toTokenIdx,
-        uint256[] memory takerTokenAmounts
-    )
-        public
-        view
-        returns (uint256[] memory makerTokenAmounts)
-    {
-        uint256 numSamples = takerTokenAmounts.length;
-        makerTokenAmounts = new uint256[](numSamples);
-        for (uint256 i = 0; i < numSamples; i++) {
-            (bool didSucceed, bytes memory resultData) =
-                curveInfo.poolAddress.staticcall.gas(CURVE_CALL_GAS)(
-                    abi.encodeWithSelector(
-                        curveInfo.sellQuoteFunctionSelector,
-                        fromTokenIdx,
-                        toTokenIdx,
-                        takerTokenAmounts[i]
-                    ));
-            uint256 buyAmount = 0;
-            if (didSucceed) {
-                buyAmount = abi.decode(resultData, (uint256));
-            }
-            makerTokenAmounts[i] = buyAmount;
-            // Break early if there are 0 amounts
-            if (makerTokenAmounts[i] == 0) {
-                break;
-            }
-        }
-    }
-
-    /// @dev Sample buy quotes from Curve.
-    /// @param curveInfo Curve information specific to this token pair.
-    /// @param fromTokenIdx Index of the taker token (what to sell).
-    /// @param toTokenIdx Index of the maker token (what to buy).
-    /// @param makerTokenAmounts Maker token buy amount for each sample.
-    /// @return takerTokenAmounts Taker amounts sold at each maker token
-    ///         amount.
-    function sampleBuysFromCurve(
-        CurveInfo memory curveInfo,
-        int128 fromTokenIdx,
-        int128 toTokenIdx,
-        uint256[] memory makerTokenAmounts
-    )
-        public
-        view
-        returns (uint256[] memory takerTokenAmounts)
-    {
-        if (curveInfo.buyQuoteFunctionSelector == bytes4(0)) {
-            // Buys not supported on this curve, so approximate it.
-            return _sampleApproximateBuys(
-                ApproximateBuyQuoteOpts({
-                    makerTokenData: abi.encode(toTokenIdx, curveInfo),
-                    takerTokenData: abi.encode(fromTokenIdx, curveInfo),
-                    getSellQuoteCallback: _sampleSellForApproximateBuyFromCurve
-                }),
-                makerTokenAmounts
-            );
-        }
-        uint256 numSamples = makerTokenAmounts.length;
-        takerTokenAmounts = new uint256[](numSamples);
-        for (uint256 i = 0; i < numSamples; i++) {
-            (bool didSucceed, bytes memory resultData) =
-                curveInfo.poolAddress.staticcall.gas(CURVE_CALL_GAS)(
-                    abi.encodeWithSelector(
-                        curveInfo.buyQuoteFunctionSelector,
-                        fromTokenIdx,
-                        toTokenIdx,
-                        makerTokenAmounts[i]
-                    ));
-            uint256 sellAmount = 0;
-            if (didSucceed) {
-                sellAmount = abi.decode(resultData, (uint256));
-            }
-            takerTokenAmounts[i] = sellAmount;
-            // Break early if there are 0 amounts
-            if (takerTokenAmounts[i] == 0) {
-                break;
-            }
-        }
-    }
-
-    function _sampleSellForApproximateBuyFromCurve(
-        bytes memory takerTokenData,
-        bytes memory makerTokenData,
-        uint256 sellAmount
-    )
-        private
-        view
-        returns (uint256 buyAmount)
-    {
-        (int128 takerTokenIdx, CurveInfo memory curveInfo) =
-            abi.decode(takerTokenData, (int128, CurveInfo));
-        (int128 makerTokenIdx) =
-            abi.decode(makerTokenData, (int128));
-        (bool success, bytes memory resultData) =
-            address(this).staticcall(abi.encodeWithSelector(
-                this.sampleSellsFromCurve.selector,
-                curveInfo,
-                takerTokenIdx,
-                makerTokenIdx,
-                _toSingleValueArray(sellAmount)
-            ));
-        if (!success) {
-            return 0;
-        }
-        // solhint-disable-next-line indent
-        return abi.decode(resultData, (uint256[]))[0];
-    }
-}
--- a/packages/asset-swapper/contracts/src/DODOSampler.sol
+++ b/packages/asset-swapper/contracts/src/DODOSampler.sol
@@ -1,211 +0,0 @@
-// SPDX-License-Identifier: Apache-2.0
-/*
-
-  Copyright 2020 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 ^0.6;
-pragma experimental ABIEncoderV2;
-
-import "./ApproximateBuys.sol";
-import "./SamplerUtils.sol";
-
-
-interface IDODOZoo {
-    function getDODO(address baseToken, address quoteToken) external view returns (address);
-}
-
-interface IDODOHelper {
-    function querySellQuoteToken(address dodo, uint256 amount) external view returns (uint256);
-}
-
-interface IDODO {
-    function querySellBaseToken(uint256 amount) external view returns (uint256);
-    function _TRADE_ALLOWED_() external view returns (bool);
-}
-
-contract DODOSampler is
-    SamplerUtils,
-    ApproximateBuys
-{
-
-    /// @dev Gas limit for DODO calls.
-    uint256 constant private DODO_CALL_GAS = 300e3; // 300k
-    struct DODOSamplerOpts {
-        address registry;
-        address helper;
-    }
-
-    /// @dev Sample sell quotes from DODO.
-    /// @param opts DODOSamplerOpts DODO Registry and helper addresses
-    /// @param takerToken Address of the taker token (what to sell).
-    /// @param makerToken Address of the maker token (what to buy).
-    /// @param takerTokenAmounts Taker token sell amount for each sample.
-    /// @return sellBase whether the bridge needs to sell the base token
-    /// @return pool the DODO pool address
-    /// @return makerTokenAmounts Maker amounts bought at each taker token
-    ///         amount.
-    function sampleSellsFromDODO(
-        DODOSamplerOpts memory opts,
-        address takerToken,
-        address makerToken,
-        uint256[] memory takerTokenAmounts
-    )
-        public
-        view
-        returns (bool sellBase, address pool, uint256[] memory makerTokenAmounts)
-    {
-        _assertValidPair(makerToken, takerToken);
-        uint256 numSamples = takerTokenAmounts.length;
-        makerTokenAmounts = new uint256[](numSamples);
-
-        pool = IDODOZoo(opts.registry).getDODO(takerToken, makerToken);
-        address baseToken;
-        // If pool exists we have the correct order of Base/Quote
-        if (pool != address(0)) {
-            baseToken = takerToken;
-            sellBase = true;
-        } else {
-            pool = IDODOZoo(opts.registry).getDODO(makerToken, takerToken);
-            // No pool either direction
-            if (address(pool) == address(0)) {
-                return (sellBase, pool, makerTokenAmounts);
-            }
-            baseToken = makerToken;
-            sellBase = false;
-        }
-
-        // DODO Pool has been disabled
-        if (!IDODO(pool)._TRADE_ALLOWED_()) {
-            return (sellBase, pool, makerTokenAmounts);
-        }
-
-        for (uint256 i = 0; i < numSamples; i++) {
-            uint256 buyAmount = _sampleSellForApproximateBuyFromDODO(
-                abi.encode(takerToken, pool, baseToken, opts.helper), // taker token data
-                abi.encode(makerToken, pool, baseToken, opts.helper), // maker token data
-                takerTokenAmounts[i]
-            );
-            makerTokenAmounts[i] = buyAmount;
-            // Break early if there are 0 amounts
-            if (makerTokenAmounts[i] == 0) {
-                break;
-            }
-        }
-    }
-
-    /// @dev Sample buy quotes from DODO.
-    /// @param opts DODOSamplerOpts DODO Registry and helper addresses
-    /// @param takerToken Address of the taker token (what to sell).
-    /// @param makerToken Address of the maker token (what to buy).
-    /// @param makerTokenAmounts Maker token sell amount for each sample.
-    /// @return sellBase whether the bridge needs to sell the base token
-    /// @return pool the DODO pool address
-    /// @return takerTokenAmounts Taker amounts sold at each maker token
-    ///         amount.
-    function sampleBuysFromDODO(
-        DODOSamplerOpts memory opts,
-        address takerToken,
-        address makerToken,
-        uint256[] memory makerTokenAmounts
-    )
-        public
-        view
-        returns (bool sellBase, address pool, uint256[] memory takerTokenAmounts)
-    {
-        _assertValidPair(makerToken, takerToken);
-        uint256 numSamples = makerTokenAmounts.length;
-        takerTokenAmounts = new uint256[](numSamples);
-
-        // Pool is BASE/QUOTE
-        // Look up the pool from the taker/maker combination
-        pool = IDODOZoo(opts.registry).getDODO(takerToken, makerToken);
-        address baseToken;
-        // If pool exists we have the correct order of Base/Quote
-        if (pool != address(0)) {
-            baseToken = takerToken;
-            sellBase = true;
-        } else {
-            // Look up the pool from the maker/taker combination
-            pool = IDODOZoo(opts.registry).getDODO(makerToken, takerToken);
-            // No pool either direction
-            if (address(pool) == address(0)) {
-                return (sellBase, pool, takerTokenAmounts);
-            }
-            baseToken = makerToken;
-            sellBase = false;
-        }
-
-        // DODO Pool has been disabled
-        if (!IDODO(pool)._TRADE_ALLOWED_()) {
-            return (sellBase, pool, takerTokenAmounts);
-        }
-
-        takerTokenAmounts = _sampleApproximateBuys(
-            ApproximateBuyQuoteOpts({
-                makerTokenData: abi.encode(makerToken, pool, baseToken, opts.helper),
-                takerTokenData: abi.encode(takerToken, pool, baseToken, opts.helper),
-                getSellQuoteCallback: _sampleSellForApproximateBuyFromDODO
-            }),
-            makerTokenAmounts
-        );
-    }
-
-    function _sampleSellForApproximateBuyFromDODO(
-        bytes memory takerTokenData,
-        bytes memory /* makerTokenData */,
-        uint256 sellAmount
-    )
-        private
-        view
-        returns (uint256)
-    {
-        (address takerToken, address pool, address baseToken, address helper) = abi.decode(
-            takerTokenData,
-            (address, address, address, address)
-        );
-
-        // We will get called to sell both the taker token and also to sell the maker token
-        if (takerToken == baseToken) {
-            // If base token then use the original query on the pool
-            try
-                IDODO(pool).querySellBaseToken
-                    {gas: DODO_CALL_GAS}
-                    (sellAmount)
-                returns (uint256 amount)
-            {
-                return amount;
-            } catch (bytes memory) {
-                // Swallow failures, leaving all results as zero.
-                return 0;
-            }
-        } else {
-            // If quote token then use helper, this is less accurate
-            try
-                IDODOHelper(helper).querySellQuoteToken
-                    {gas: DODO_CALL_GAS}
-                    (pool, sellAmount)
-                returns (uint256 amount)
-            {
-                return amount;
-            } catch (bytes memory) {
-                // Swallow failures, leaving all results as zero.
-                return 0;
-            }
-        }
-    }
-
-}
--- a/packages/asset-swapper/contracts/src/DODOV2Sampler.sol
+++ b/packages/asset-swapper/contracts/src/DODOV2Sampler.sol
@@ -1,204 +0,0 @@
-// SPDX-License-Identifier: Apache-2.0
-/*
-
-  Copyright 2021 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 ^0.6;
-pragma experimental ABIEncoderV2;
-
-import "./ApproximateBuys.sol";
-import "./SamplerUtils.sol";
-
-interface IDODOV2Registry {
-    function getDODOPool(address baseToken, address quoteToken)
-        external
-        view
-        returns (address[] memory machines);
-}
-
-interface IDODOV2Pool {
-    function querySellBase(address trader, uint256 payBaseAmount)
-        external
-        view
-        returns (uint256 receiveQuoteAmount, uint256 mtFee);
-
-    function querySellQuote(address trader, uint256 payQuoteAmount)
-        external
-        view
-        returns (uint256 receiveBaseAmount, uint256 mtFee);
-}
-
-contract DODOV2Sampler is
-    SamplerUtils,
-    ApproximateBuys
-{
-
-    /// @dev Gas limit for DODO V2 calls.
-    uint256 constant private DODO_V2_CALL_GAS = 300e3; // 300k
-
-    /// @dev Sample sell quotes from DODO V2.
-    /// @param registry Address of the registry to look up.
-    /// @param offset offset index for the pool in the registry.
-    /// @param takerToken Address of the taker token (what to sell).
-    /// @param makerToken Address of the maker token (what to buy).
-    /// @param takerTokenAmounts Taker token sell amount for each sample.
-    /// @return sellBase whether the bridge needs to sell the base token
-    /// @return pool the DODO pool address
-    /// @return makerTokenAmounts Maker amounts bought at each taker token
-    ///         amount.
-    function sampleSellsFromDODOV2(
-        address registry,
-        uint256 offset,
-        address takerToken,
-        address makerToken,
-        uint256[] memory takerTokenAmounts
-    )
-        public
-        view
-        returns (bool sellBase, address pool, uint256[] memory makerTokenAmounts)
-    {
-        _assertValidPair(makerToken, takerToken);
-
-        uint256 numSamples = takerTokenAmounts.length;
-        makerTokenAmounts = new uint256[](numSamples);
-
-        (pool, sellBase) = _getNextDODOV2Pool(registry, offset, takerToken, makerToken);
-        if (pool == address(0)) {
-            return (sellBase, pool, makerTokenAmounts);
-        }
-
-        for (uint256 i = 0; i < numSamples; i++) {
-            uint256 buyAmount = _sampleSellForApproximateBuyFromDODOV2(
-                abi.encode(takerToken, pool, sellBase), // taker token data
-                abi.encode(makerToken, pool, sellBase), // maker token data
-                takerTokenAmounts[i]
-            );
-            makerTokenAmounts[i] = buyAmount;
-            // Break early if there are 0 amounts
-            if (makerTokenAmounts[i] == 0) {
-                break;
-            }
-        }
-    }
-
-    /// @dev Sample buy quotes from DODO.
-    /// @param registry Address of the registry to look up.
-    /// @param offset offset index for the pool in the registry.
-    /// @param takerToken Address of the taker token (what to sell).
-    /// @param makerToken Address of the maker token (what to buy).
-    /// @param makerTokenAmounts Maker token sell amount for each sample.
-    /// @return sellBase whether the bridge needs to sell the base token
-    /// @return pool the DODO pool address
-    /// @return takerTokenAmounts Taker amounts sold at each maker token
-    ///         amount.
-    function sampleBuysFromDODOV2(
-        address registry,
-        uint256 offset,
-        address takerToken,
-        address makerToken,
-        uint256[] memory makerTokenAmounts
-    )
-        public
-        view
-        returns (bool sellBase, address pool, uint256[] memory takerTokenAmounts)
-    {
-        _assertValidPair(makerToken, takerToken);
-        (pool, sellBase) = _getNextDODOV2Pool(registry, offset, takerToken, makerToken);
-        if (pool == address(0)) {
-            return (sellBase, pool, takerTokenAmounts);
-        }
-        uint256 numSamples = makerTokenAmounts.length;
-        takerTokenAmounts = new uint256[](numSamples);
-
-        takerTokenAmounts = _sampleApproximateBuys(
-            ApproximateBuyQuoteOpts({
-                makerTokenData: abi.encode(makerToken, pool, !sellBase),
-                takerTokenData: abi.encode(takerToken, pool, sellBase),
-                getSellQuoteCallback: _sampleSellForApproximateBuyFromDODOV2
-            }),
-            makerTokenAmounts
-        );
-    }
-
-    function _sampleSellForApproximateBuyFromDODOV2(
-        bytes memory takerTokenData,
-        bytes memory /* makerTokenData */,
-        uint256 sellAmount
-    )
-        private
-        view
-        returns (uint256)
-    {
-        (address takerToken, address pool, bool sellBase) = abi.decode(
-            takerTokenData,
-            (address, address, bool)
-        );
-
-        // We will get called to sell both the taker token and also to sell the maker token
-        // since we use approximate buy for sell and buy functions
-        if (sellBase) {
-            try
-                IDODOV2Pool(pool).querySellBase
-                    { gas: DODO_V2_CALL_GAS }
-                    (address(0), sellAmount)
-                returns (uint256 amount, uint256)
-            {
-                return amount;
-            } catch {
-                return 0;
-            }
-        } else {
-            try
-                IDODOV2Pool(pool).querySellQuote
-                    { gas: DODO_V2_CALL_GAS }
-                    (address(0), sellAmount)
-                returns (uint256 amount, uint256)
-            {
-                return amount;
-            } catch {
-                return 0;
-            }
-        }
-    }
-
-    function _getNextDODOV2Pool(
-        address registry,
-        uint256 offset,
-        address takerToken,
-        address makerToken
-    )
-        internal
-        view
-        returns (address machine, bool sellBase)
-    {
-        // Query in base -> quote direction, if a pool is found then we are selling the base
-        address[] memory machines = IDODOV2Registry(registry).getDODOPool(takerToken, makerToken);
-        sellBase = true;
-        if (machines.length == 0) {
-            // Query in quote -> base direction, if a pool is found then we are selling the quote
-            machines = IDODOV2Registry(registry).getDODOPool(makerToken, takerToken);
-            sellBase = false;
-        }
-
-        if (offset >= machines.length) {
-            return (address(0), false);
-        }
-
-        machine = machines[offset];
-    }
-
-}
--- a/packages/asset-swapper/contracts/src/ERC20BridgeSampler.sol
+++ b/packages/asset-swapper/contracts/src/ERC20BridgeSampler.sol
@@ -1,95 +0,0 @@
-// SPDX-License-Identifier: Apache-2.0
-/*
-
-  Copyright 2020 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 ^0.6;
-pragma experimental ABIEncoderV2;
-
-import "./BalancerSampler.sol";
-import "./BalancerV2Sampler.sol";
-import "./BancorSampler.sol";
-import "./CompoundSampler.sol";
-import "./CurveSampler.sol";
-import "./DODOSampler.sol";
-import "./DODOV2Sampler.sol";
-import "./KyberSampler.sol";
-import "./KyberDmmSampler.sol";
-import "./LidoSampler.sol";
-import "./LiquidityProviderSampler.sol";
-import "./MakerPSMSampler.sol";
-import "./MultiBridgeSampler.sol";
-import "./MStableSampler.sol";
-import "./MooniswapSampler.sol";
-import "./NativeOrderSampler.sol";
-import "./ShellSampler.sol";
-import "./SmoothySampler.sol";
-import "./TwoHopSampler.sol";
-import "./UniswapSampler.sol";
-import "./UniswapV2Sampler.sol";
-import "./UniswapV3Sampler.sol";
-import "./UtilitySampler.sol";
-
-
-contract ERC20BridgeSampler is
-    BalancerSampler,
-    BalancerV2Sampler,
-    BancorSampler,
-    CompoundSampler,
-    CurveSampler,
-    DODOSampler,
-    DODOV2Sampler,
-    KyberSampler,
-    KyberDmmSampler,
-    LidoSampler,
-    LiquidityProviderSampler,
-    MakerPSMSampler,
-    MStableSampler,
-    MooniswapSampler,
-    MultiBridgeSampler,
-    NativeOrderSampler,
-    ShellSampler,
-    SmoothySampler,
-    TwoHopSampler,
-    UniswapSampler,
-    UniswapV2Sampler,
-    UniswapV3Sampler,
-    UtilitySampler
-{
-
-    struct CallResults {
-        bytes data;
-        bool success;
-    }
-
-    /// @dev Call multiple public functions on this contract in a single transaction.
-    /// @param callDatas ABI-encoded call data for each function call.
-    /// @return callResults ABI-encoded results data for each call.
-    function batchCall(bytes[] calldata callDatas)
-        external
-        returns (CallResults[] memory callResults)
-    {
-        callResults = new CallResults[](callDatas.length);
-        for (uint256 i = 0; i != callDatas.length; ++i) {
-            callResults[i].success = true;
-            if (callDatas[i].length == 0) {
-                continue;
-            }
-            (callResults[i].success, callResults[i].data) = address(this).call(callDatas[i]);
-        }
-    }
-}
--- a/packages/asset-swapper/contracts/src/KyberDmmSampler.sol
+++ b/packages/asset-swapper/contracts/src/KyberDmmSampler.sol
@@ -1,179 +0,0 @@
-// SPDX-License-Identifier: Apache-2.0
-/*
-
-  Copyright 2020 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 ^0.6;
-pragma experimental ABIEncoderV2;
-
-interface IKyberDmmPool {
-
-    function totalSupply()
-        external
-        view
-        returns (uint256);
-}
-
-interface IKyberDmmFactory {
-
-    function getPools(address token0, address token1)
-        external
-        view
-        returns (address[] memory _tokenPools);
-}
-
-interface IKyberDmmRouter {
-
-    function factory() external view returns (address);
-
-    function getAmountsOut(uint256 amountIn, address[] calldata pools, address[] calldata path)
-        external
-        view
-        returns (uint256[] memory amounts);
-
-    function getAmountsIn(uint256 amountOut, address[] calldata pools, address[] calldata path)
-        external
-        view
-        returns (uint256[] memory amounts);
-}
-
-
-
-contract KyberDmmSampler
-{
-    /// @dev Gas limit for KyberDmm calls.
-    uint256 constant private KYBER_DMM_CALL_GAS = 150e3; // 150k
-
-    /// @dev Sample sell quotes from KyberDmm.
-    /// @param router Router to look up tokens and amounts
-    /// @param path Token route. Should be takerToken -> makerToken
-    /// @param takerTokenAmounts Taker token sell amount for each sample.
-    /// @return pools The pool addresses involved in the multi path trade
-    /// @return makerTokenAmounts Maker amounts bought at each taker token
-    ///         amount.
-    function sampleSellsFromKyberDmm(
-        address router,
-        address[] memory path,
-        uint256[] memory takerTokenAmounts
-    )
-        public
-        view
-        returns (address[] memory pools, uint256[] memory makerTokenAmounts)
-    {
-        uint256 numSamples = takerTokenAmounts.length;
-        makerTokenAmounts = new uint256[](numSamples);
-        pools = _getKyberDmmPools(router, path);
-        if (pools.length == 0) {
-            return (pools, makerTokenAmounts);
-        }
-        for (uint256 i = 0; i < numSamples; i++) {
-            try
-                IKyberDmmRouter(router).getAmountsOut
-                    {gas: KYBER_DMM_CALL_GAS}
-                    (takerTokenAmounts[i], pools, path)
-                returns (uint256[] memory amounts)
-            {
-                makerTokenAmounts[i] = amounts[path.length - 1];
-                // Break early if there are 0 amounts
-                if (makerTokenAmounts[i] == 0) {
-                    break;
-                }
-            } catch (bytes memory) {
-                // Swallow failures, leaving all results as zero.
-                break;
-            }
-        }
-    }
-
-    /// @dev Sample buy quotes from KyberDmm.
-    /// @param router Router to look up tokens and amounts
-    /// @param path Token route. Should be takerToken -> makerToken.
-    /// @param makerTokenAmounts Maker token buy amount for each sample.
-    /// @return pools The pool addresses involved in the multi path trade
-    /// @return takerTokenAmounts Taker amounts sold at each maker token
-    ///         amount.
-    function sampleBuysFromKyberDmm(
-        address router,
-        address[] memory path,
-        uint256[] memory makerTokenAmounts
-    )
-        public
-        view
-        returns (address[] memory pools, uint256[] memory takerTokenAmounts)
-    {
-        uint256 numSamples = makerTokenAmounts.length;
-        takerTokenAmounts = new uint256[](numSamples);
-        pools = _getKyberDmmPools(router, path);
-        if (pools.length == 0) {
-            return (pools, takerTokenAmounts);
-        }
-        for (uint256 i = 0; i < numSamples; i++) {
-            try
-                IKyberDmmRouter(router).getAmountsIn
-                    {gas: KYBER_DMM_CALL_GAS}
-                    (makerTokenAmounts[i], pools, path)
-                returns (uint256[] memory amounts)
-            {
-                takerTokenAmounts[i] = amounts[0];
-                // Break early if there are 0 amounts
-                if (takerTokenAmounts[i] == 0) {
-                    break;
-                }
-            } catch (bytes memory) {
-                // Swallow failures, leaving all results as zero.
-                break;
-            }
-        }
-    }
-
-    function _getKyberDmmPools(
-        address router,
-        address[] memory path
-    )
-        private
-        view
-        returns (address[] memory pools)
-    {
-        IKyberDmmFactory factory = IKyberDmmFactory(IKyberDmmRouter(router).factory());
-        pools = new address[](path.length - 1);
-        for (uint256 i = 0; i < pools.length; i++) {
-            // find the best pool
-            address[] memory allPools;
-            try
-                factory.getPools
-                    {gas: KYBER_DMM_CALL_GAS}
-                    (path[i], path[i + 1])
-                returns (address[] memory allPools)
-            {
-                if (allPools.length == 0) {
-                    return new address[](0);
-                }
-
-                uint256 maxSupply = 0;
-                for (uint256 j = 0; j < allPools.length; j++) {
-                    uint256 totalSupply = IKyberDmmPool(allPools[j]).totalSupply();
-                    if (totalSupply > maxSupply) {
-                        maxSupply = totalSupply;
-                        pools[i] = allPools[j];
-                    }
-                }
-            } catch (bytes memory) {
-                return new address[](0);
-            }
-        }
-    }
-}
--- a/packages/asset-swapper/contracts/src/KyberSampler.sol
+++ b/packages/asset-swapper/contracts/src/KyberSampler.sol
@@ -1,301 +0,0 @@
-// SPDX-License-Identifier: Apache-2.0
-/*
-
-  Copyright 2020 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 ^0.6;
-pragma experimental ABIEncoderV2;
-
-import "./interfaces/IKyberNetwork.sol";
-import "./ApproximateBuys.sol";
-import "./SamplerUtils.sol";
-
-
-contract KyberSampler is
-    SamplerUtils,
-    ApproximateBuys
-{
-    /// @dev Gas limit for Kyber calls.
-    uint256 constant private KYBER_CALL_GAS = 500e3; // 500k
-    /// @dev Kyber ETH pseudo-address.
-    address constant internal KYBER_ETH_ADDRESS = 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE;
-
-    struct KyberSamplerOpts {
-        uint256 reserveOffset;
-        address hintHandler;
-        address networkProxy;
-        address weth;
-        bytes hint;
-    }
-
-    /// @dev Sample sell quotes from Kyber.
-    /// @param opts KyberSamplerOpts The nth reserve
-    /// @param takerToken Address of the taker token (what to sell).
-    /// @param makerToken Address of the maker token (what to buy).
-    /// @param takerTokenAmounts Taker token sell amount for each sample.
-    /// @return reserveId The id of the reserve found at reserveOffset
-    /// @return hint The hint for the selected reserve
-    /// @return makerTokenAmounts Maker amounts bought at each taker token amount.
-    function sampleSellsFromKyberNetwork(
-        KyberSamplerOpts memory opts,
-        address takerToken,
-        address makerToken,
-        uint256[] memory takerTokenAmounts
-    )
-        public
-        view
-        returns (bytes32 reserveId, bytes memory hint, uint256[] memory makerTokenAmounts)
-    {
-        _assertValidPair(makerToken, takerToken);
-        reserveId = _getNextReserveId(opts, takerToken, makerToken);
-        if (reserveId == 0x0) {
-            return (reserveId, hint, makerTokenAmounts);
-        }
-        opts.hint = this.encodeKyberHint(opts, reserveId, takerToken, makerToken);
-        hint = opts.hint;
-
-        uint256 numSamples = takerTokenAmounts.length;
-        makerTokenAmounts = new uint256[](numSamples);
-        for (uint256 i = 0; i < numSamples; i++) {
-            uint256 value = this.sampleSellFromKyberNetwork(
-                opts,
-                takerToken,
-                makerToken,
-                takerTokenAmounts[i]
-            );
-            makerTokenAmounts[i] = value;
-            // Break early if there are 0 amounts
-            if (makerTokenAmounts[i] == 0) {
-                break;
-            }
-        }
-    }
-
-    /// @dev Sample buy quotes from Kyber.
-    /// @param opts KyberSamplerOpts The nth reserve
-    /// @param takerToken Address of the taker token (what to sell).
-    /// @param makerToken Address of the maker token (what to buy).
-    /// @param makerTokenAmounts Maker token buy amount for each sample.
-    /// @return reserveId The id of the reserve found at reserveOffset
-    /// @return hint The hint for the selected reserve
-    /// @return takerTokenAmounts Taker amounts sold at each maker token amount.
-    function sampleBuysFromKyberNetwork(
-        KyberSamplerOpts memory opts,
-        address takerToken,
-        address makerToken,
-        uint256[] memory makerTokenAmounts
-    )
-        public
-        view
-        returns (bytes32 reserveId, bytes memory hint, uint256[] memory takerTokenAmounts)
-    {
-        _assertValidPair(makerToken, takerToken);
-
-        reserveId = _getNextReserveId(opts, takerToken, makerToken);
-        if (reserveId == 0x0) {
-            return (reserveId, hint, takerTokenAmounts);
-        }
-        opts.hint = this.encodeKyberHint(opts, reserveId, takerToken, makerToken);
-        hint = opts.hint;
-
-        takerTokenAmounts = _sampleApproximateBuys(
-            ApproximateBuyQuoteOpts({
-                makerTokenData: abi.encode(makerToken, opts),
-                takerTokenData: abi.encode(takerToken, opts),
-                getSellQuoteCallback: _sampleSellForApproximateBuyFromKyber
-            }),
-            makerTokenAmounts
-        );
-        return (reserveId, hint, takerTokenAmounts);
-    }
-
-    function encodeKyberHint(
-        KyberSamplerOpts memory opts,
-        bytes32 reserveId,
-        address takerToken,
-        address makerToken
-    )
-        public
-        view
-        returns (bytes memory hint)
-    {
-        // Build a hint selecting the single reserve
-        IKyberHintHandler kyberHint = IKyberHintHandler(opts.hintHandler);
-
-        // All other reserves should be ignored with this hint
-        bytes32[] memory selectedReserves = new bytes32[](1);
-        selectedReserves[0] = reserveId;
-        uint256[] memory emptySplits = new uint256[](0);
-
-        if (takerToken == opts.weth) {
-            // ETH to Token
-            try
-                kyberHint.buildEthToTokenHint
-                    {gas: KYBER_CALL_GAS}
-                    (
-                        makerToken,
-                        IKyberHintHandler.TradeType.MaskIn,
-                        selectedReserves,
-                        emptySplits
-                    )
-                returns (bytes memory result)
-            {
-                return result;
-            } catch (bytes memory) {
-                // Swallow failures, leaving all results as zero.
-            }
-        } else if (makerToken == opts.weth) {
-            // Token to ETH
-            try
-                kyberHint.buildTokenToEthHint
-                    {gas: KYBER_CALL_GAS}
-                    (
-                        takerToken,
-                        IKyberHintHandler.TradeType.MaskIn,
-                        selectedReserves,
-                        emptySplits
-                    )
-                returns (bytes memory result)
-            {
-                return result;
-            } catch (bytes memory) {
-                // Swallow failures, leaving all results as zero.
-            }
-
-        } else {
-            // Token to Token
-            // We use the same reserve both ways
-            try
-                kyberHint.buildTokenToTokenHint
-                    {gas: KYBER_CALL_GAS}
-                    (
-                        takerToken,
-                        IKyberHintHandler.TradeType.MaskIn,
-                        selectedReserves,
-                        emptySplits,
-                        makerToken,
-                        IKyberHintHandler.TradeType.MaskIn,
-                        selectedReserves,
-                        emptySplits
-                    )
-                returns (bytes memory result)
-            {
-                return result;
-            } catch (bytes memory) {
-                // Swallow failures, leaving all results as zero.
-            }
-        }
-    }
-
-    function _sampleSellForApproximateBuyFromKyber(
-        bytes memory takerTokenData,
-        bytes memory makerTokenData,
-        uint256 sellAmount
-    )
-        private
-        view
-        returns (uint256)
-    {
-        (address makerToken, KyberSamplerOpts memory opts) =
-            abi.decode(makerTokenData, (address, KyberSamplerOpts));
-        (address takerToken, ) =
-            abi.decode(takerTokenData, (address, KyberSamplerOpts));
-        try
-            this.sampleSellFromKyberNetwork
-                (opts, takerToken, makerToken, sellAmount)
-            returns (uint256 amount)
-        {
-            return amount;
-        } catch (bytes memory) {
-            // Swallow failures, leaving all results as zero.
-            return 0;
-        }
-    }
-
-    function sampleSellFromKyberNetwork(
-        KyberSamplerOpts memory opts,
-        address takerToken,
-        address makerToken,
-        uint256 takerTokenAmount
-    )
-        public
-        view
-        returns (uint256 makerTokenAmount)
-    {
-        // If there is no hint do not continue
-        if (opts.hint.length == 0) {
-            return 0;
-        }
-
-        try
-            IKyberNetworkProxy(opts.networkProxy).getExpectedRateAfterFee
-                {gas: KYBER_CALL_GAS}
-                (
-                    takerToken == opts.weth ? KYBER_ETH_ADDRESS : takerToken,
-                    makerToken == opts.weth ? KYBER_ETH_ADDRESS : makerToken,
-                    takerTokenAmount,
-                    0, // fee
-                    opts.hint
-                )
-            returns (uint256 rate)
-        {
-            uint256 makerTokenDecimals = _getTokenDecimals(makerToken);
-            uint256 takerTokenDecimals = _getTokenDecimals(takerToken);
-            makerTokenAmount =
-                rate *
-                takerTokenAmount *
-                10 ** makerTokenDecimals /
-                10 ** takerTokenDecimals /
-                10 ** 18;
-            return makerTokenAmount;
-        } catch (bytes memory) {
-            // Swallow failures, leaving all results as zero.
-            return 0;
-        }
-    }
-
-    function _getNextReserveId(
-        KyberSamplerOpts memory opts,
-        address takerToken,
-        address makerToken
-    )
-        internal
-        view
-        returns (bytes32 reserveId)
-    {
-        // Fetch the registered reserves for this pair
-        IKyberHintHandler kyberHint = IKyberHintHandler(opts.hintHandler);
-        (bytes32[] memory reserveIds, ,) = kyberHint.getTradingReserves(
-            takerToken == opts.weth ? KYBER_ETH_ADDRESS : takerToken,
-            makerToken == opts.weth ? KYBER_ETH_ADDRESS : makerToken,
-            true,
-            new bytes(0) // empty hint
-        );
-
-        if (opts.reserveOffset >= reserveIds.length) {
-            return 0x0;
-        }
-
-        reserveId = reserveIds[opts.reserveOffset];
-        // Ignore Kyber Bridged Reserves (0xbb)
-        if (uint256(reserveId >> 248) == 0xbb) {
-            return 0x0;
-        }
-
-        return reserveId;
-    }
-}
--- a/packages/asset-swapper/contracts/src/LidoSampler.sol
+++ b/packages/asset-swapper/contracts/src/LidoSampler.sol
@@ -1,91 +0,0 @@
-// SPDX-License-Identifier: Apache-2.0
-/*
-
-  Copyright 2021 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 ^0.6;
-pragma experimental ABIEncoderV2;
-
-import "./SamplerUtils.sol";
-
-contract LidoSampler is SamplerUtils {
-    struct LidoInfo {
-        address stEthToken;
-        address wethToken;
-    }
-
-    /// @dev Sample sell quotes from Lido
-    /// @param lidoInfo Info regarding a specific Lido deployment
-    /// @param takerToken Address of the taker token (what to sell).
-    /// @param makerToken Address of the maker token (what to buy).
-    /// @param takerTokenAmounts Taker token sell amount for each sample.
-    /// @return makerTokenAmounts Maker amounts bought at each taker token
-    ///         amount.
-    function sampleSellsFromLido(
-        LidoInfo memory lidoInfo,
-        address takerToken,
-        address makerToken,
-        uint256[] memory takerTokenAmounts
-    )
-        public
-        pure
-        returns (uint256[] memory)
-    {
-        _assertValidPair(makerToken, takerToken);
-
-        if (takerToken != lidoInfo.wethToken || makerToken != address(lidoInfo.stEthToken)) {
-            // Return 0 values if not selling WETH for stETH
-            uint256 numSamples = takerTokenAmounts.length;
-            uint256[] memory makerTokenAmounts = new uint256[](numSamples);
-            return makerTokenAmounts;
-        }
-
-        // Minting stETH is always 1:1 therefore we can just return the same amounts back
-        return takerTokenAmounts;
-    }
-
-    /// @dev Sample buy quotes from Lido.
-    /// @param lidoInfo Info regarding a specific Lido deployment
-    /// @param takerToken Address of the taker token (what to sell).
-    /// @param makerToken Address of the maker token (what to buy).
-    /// @param makerTokenAmounts Maker token buy amount for each sample.
-    /// @return takerTokenAmounts Taker amounts sold at each maker token
-    ///         amount.
-    function sampleBuysFromLido(
-        LidoInfo memory lidoInfo,
-        address takerToken,
-        address makerToken,
-        uint256[] memory makerTokenAmounts
-    )
-        public
-        pure
-        returns (uint256[] memory)
-    {
-        _assertValidPair(makerToken, takerToken);
-
-        if (takerToken != lidoInfo.wethToken || makerToken != address(lidoInfo.stEthToken)) {
-            // Return 0 values if not buying stETH for WETH
-            uint256 numSamples = makerTokenAmounts.length;
-            uint256[] memory takerTokenAmounts = new uint256[](numSamples);
-            return takerTokenAmounts;
-        }
-
-        // Minting stETH is always 1:1 therefore we can just return the same amounts back
-        return makerTokenAmounts;
-    }
-
-}
--- a/packages/asset-swapper/contracts/src/LiquidityProviderSampler.sol
+++ b/packages/asset-swapper/contracts/src/LiquidityProviderSampler.sol
@@ -1,132 +0,0 @@
-// SPDX-License-Identifier: Apache-2.0
-/*
-
-  Copyright 2020 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 ^0.6;
-pragma experimental ABIEncoderV2;
-
-import "@0x/contracts-utils/contracts/src/v06/LibBytesV06.sol";
-import "@0x/contracts-zero-ex/contracts/src/vendor/ILiquidityProvider.sol";
-import "./ApproximateBuys.sol";
-import "./SamplerUtils.sol";
-
-
-contract LiquidityProviderSampler is
-    SamplerUtils,
-    ApproximateBuys
-{
-    /// @dev Default gas limit for liquidity provider calls.
-    uint256 constant private DEFAULT_CALL_GAS = 400e3; // 400k
-
-    /// @dev Sample sell quotes from an arbitrary on-chain liquidity provider.
-    /// @param providerAddress Address of the liquidity provider.
-    /// @param takerToken Address of the taker token (what to sell).
-    /// @param makerToken Address of the maker token (what to buy).
-    /// @param takerTokenAmounts Taker token sell amount for each sample.
-    /// @return makerTokenAmounts Maker amounts bought at each taker token
-    ///         amount.
-    function sampleSellsFromLiquidityProvider(
-        address providerAddress,
-        address takerToken,
-        address makerToken,
-        uint256[] memory takerTokenAmounts
-    )
-        public
-        view
-        returns (uint256[] memory makerTokenAmounts)
-    {
-        // Initialize array of maker token amounts.
-        uint256 numSamples = takerTokenAmounts.length;
-        makerTokenAmounts = new uint256[](numSamples);
-
-        for (uint256 i = 0; i < numSamples; i++) {
-            try
-                ILiquidityProvider(providerAddress).getSellQuote
-                    {gas: DEFAULT_CALL_GAS}
-                    (
-                        IERC20TokenV06(takerToken),
-                        IERC20TokenV06(makerToken),
-                        takerTokenAmounts[i]
-                    )
-                returns (uint256 amount)
-            {
-                makerTokenAmounts[i] = amount;
-                // Break early if there are 0 amounts
-                if (makerTokenAmounts[i] == 0) {
-                    break;
-                }
-            } catch (bytes memory) {
-                // Swallow failures, leaving all results as zero.
-                break;
-            }
-        }
-    }
-
-    /// @dev Sample buy quotes from an arbitrary on-chain liquidity provider.
-    /// @param providerAddress Address of the liquidity provider.
-    /// @param takerToken Address of the taker token (what to sell).
-    /// @param makerToken Address of the maker token (what to buy).
-    /// @param makerTokenAmounts Maker token buy amount for each sample.
-    /// @return takerTokenAmounts Taker amounts sold at each maker token
-    ///         amount.
-    function sampleBuysFromLiquidityProvider(
-        address providerAddress,
-        address takerToken,
-        address makerToken,
-        uint256[] memory makerTokenAmounts
-    )
-        public
-        view
-        returns (uint256[] memory takerTokenAmounts)
-    {
-        takerTokenAmounts = _sampleApproximateBuys(
-            ApproximateBuyQuoteOpts({
-                makerTokenData: abi.encode(makerToken, providerAddress),
-                takerTokenData: abi.encode(takerToken, providerAddress),
-                getSellQuoteCallback: _sampleSellForApproximateBuyFromLiquidityProvider
-            }),
-            makerTokenAmounts
-        );
-    }
-
-    function _sampleSellForApproximateBuyFromLiquidityProvider(
-        bytes memory takerTokenData,
-        bytes memory makerTokenData,
-        uint256 sellAmount
-    )
-        private
-        view
-        returns (uint256 buyAmount)
-    {
-        (address takerToken, address providerAddress) =
-            abi.decode(takerTokenData, (address, address));
-        (address makerToken) =
-            abi.decode(makerTokenData, (address));
-        try
-            this.sampleSellsFromLiquidityProvider
-                {gas: DEFAULT_CALL_GAS}
-                (providerAddress, takerToken, makerToken, _toSingleValueArray(sellAmount))
-            returns (uint256[] memory amounts)
-        {
-            return amounts[0];
-        } catch (bytes memory) {
-            // Swallow failures, leaving all results as zero.
-            return 0;
-        }
-    }
-}
--- a/packages/asset-swapper/contracts/src/MStableSampler.sol
+++ b/packages/asset-swapper/contracts/src/MStableSampler.sol
@@ -1,127 +0,0 @@
-// SPDX-License-Identifier: Apache-2.0
-/*
-
-  Copyright 2020 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 ^0.6;
-pragma experimental ABIEncoderV2;
-
-import "./interfaces/IMStable.sol";
-import "./ApproximateBuys.sol";
-import "./SamplerUtils.sol";
-
-
-contract MStableSampler is
-    SamplerUtils,
-    ApproximateBuys
-{
-    /// @dev Default gas limit for mStable calls.
-    uint256 constant private DEFAULT_CALL_GAS = 800e3; // 800k
-
-    /// @dev Sample sell quotes from the mStable contract
-    /// @param router Address of the mStable contract
-    /// @param takerToken Address of the taker token (what to sell).
-    /// @param makerToken Address of the maker token (what to buy).
-    /// @param takerTokenAmounts Taker token sell amount for each sample.
-    /// @return makerTokenAmounts Maker amounts bought at each taker token
-    ///         amount.
-    function sampleSellsFromMStable(
-        address router,
-        address takerToken,
-        address makerToken,
-        uint256[] memory takerTokenAmounts
-    )
-        public
-        view
-        returns (uint256[] memory makerTokenAmounts)
-    {
-        _assertValidPair(makerToken, takerToken);
-        // Initialize array of maker token amounts.
-        uint256 numSamples = takerTokenAmounts.length;
-        makerTokenAmounts = new uint256[](numSamples);
-
-        for (uint256 i = 0; i < numSamples; i++) {
-            try
-                IMStable(router).getSwapOutput
-                    {gas: DEFAULT_CALL_GAS}
-                    (takerToken, makerToken, takerTokenAmounts[i])
-                returns (uint256 amount)
-            {
-                makerTokenAmounts[i] = amount;
-                // Break early if there are 0 amounts
-                if (makerTokenAmounts[i] == 0) {
-                    break;
-                }
-            } catch (bytes memory) {
-                // Swallow failures, leaving all results as zero.
-                break;
-            }
-        }
-    }
-
-    /// @dev Sample buy quotes from MStable contract
-    /// @param router Address of the mStable contract
-    /// @param takerToken Address of the taker token (what to sell).
-    /// @param makerToken Address of the maker token (what to buy).
-    /// @param makerTokenAmounts Maker token buy amount for each sample.
-    /// @return takerTokenAmounts Taker amounts sold at each maker token
-    ///         amount.
-    function sampleBuysFromMStable(
-        address router,
-        address takerToken,
-        address makerToken,
-        uint256[] memory makerTokenAmounts
-    )
-        public
-        view
-        returns (uint256[] memory takerTokenAmounts)
-    {
-        return _sampleApproximateBuys(
-            ApproximateBuyQuoteOpts({
-                makerTokenData: abi.encode(makerToken, router),
-                takerTokenData: abi.encode(takerToken, router),
-                getSellQuoteCallback: _sampleSellForApproximateBuyFromMStable
-            }),
-            makerTokenAmounts
-        );
-    }
-
-    function _sampleSellForApproximateBuyFromMStable(
-        bytes memory takerTokenData,
-        bytes memory makerTokenData,
-        uint256 sellAmount
-    )
-        private
-        view
-        returns (uint256 buyAmount)
-    {
-        (address takerToken, address router) =
-            abi.decode(takerTokenData, (address, address));
-        (address makerToken) =
-            abi.decode(makerTokenData, (address));
-        try
-            this.sampleSellsFromMStable
-                (router, takerToken, makerToken, _toSingleValueArray(sellAmount))
-            returns (uint256[] memory amounts)
-        {
-            return amounts[0];
-        } catch (bytes memory) {
-            // Swallow failures, leaving all results as zero.
-            return 0;
-        }
-    }
-}
--- a/packages/asset-swapper/contracts/src/MakerPSMSampler.sol
+++ b/packages/asset-swapper/contracts/src/MakerPSMSampler.sol
@@ -1,267 +0,0 @@
-// SPDX-License-Identifier: Apache-2.0
-/*
-
-  Copyright 2021 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 ^0.6;
-pragma experimental ABIEncoderV2;
-
-import "./SamplerUtils.sol";
-import "@0x/contracts-utils/contracts/src/v06/LibMathV06.sol";
-
-interface IPSM {
-    // @dev Get the fee for selling USDC to DAI in PSM
-    // @return tin toll in [wad]
-    function tin() external view returns (uint256);
-    // @dev Get the fee for selling DAI to USDC in PSM
-    // @return tout toll out [wad]
-    function tout() external view returns (uint256);
-
-    // @dev Get the address of the PSM state Vat
-    // @return address of the Vat
-    function vat() external view returns (address);
-
-    // @dev Get the address of the underlying vault powering PSM
-    // @return address of gemJoin contract
-    function gemJoin() external view returns (address);
-
-    // @dev Get the address of DAI
-    // @return address of DAI contract
-    function dai() external view returns (address);
-
-    // @dev Sell USDC for DAI
-    // @param usr The address of the account trading USDC for DAI.
-    // @param gemAmt The amount of USDC to sell in USDC base units
-    function sellGem(
-        address usr,
-        uint256 gemAmt
-    ) external;
-    // @dev Buy USDC for DAI
-    // @param usr The address of the account trading DAI for USDC
-    // @param gemAmt The amount of USDC to buy in USDC base units
-    function buyGem(
-        address usr,
-        uint256 gemAmt
-    ) external;
-}
-
-interface IVAT {
-    // @dev Get a collateral type by identifier
-    // @param ilkIdentifier bytes32 identifier. Example: ethers.utils.formatBytes32String("PSM-USDC-A")
-    // @return ilk
-    // @return ilk.Art Total Normalised Debt in wad
-    // @return ilk.rate Accumulated Rates in ray
-    // @return ilk.spot Price with Safety Margin in ray
-    // @return ilk.line Debt Ceiling in rad
-    // @return ilk.dust Urn Debt Floor in rad
-    function ilks(
-        bytes32 ilkIdentifier
-    ) external view returns (
-        uint256 Art,
-        uint256 rate,
-        uint256 spot,
-        uint256 line,
-        uint256 dust
-    );
-}
-
-contract MakerPSMSampler is
-    SamplerUtils
-{
-    using LibSafeMathV06 for uint256;
-
-    /// @dev Information about which PSM module to use
-    struct MakerPsmInfo {
-        address psmAddress;
-        bytes32 ilkIdentifier;
-        address gemTokenAddress;
-    }
-
-    /// @dev Gas limit for MakerPsm calls.
-    uint256 constant private MAKER_PSM_CALL_GAS = 300e3; // 300k
-
-
-    // Maker units
-    // wad: fixed point decimal with 18 decimals (for basic quantities, e.g. balances)
-    uint256 constant private WAD = 10 ** 18;
-    // ray: fixed point decimal with 27 decimals (for precise quantites, e.g. ratios)
-    uint256 constant private RAY = 10 ** 27;
-    // rad: fixed point decimal with 45 decimals (result of integer multiplication with a wad and a ray)
-    uint256 constant private RAD = 10 ** 45;
-    // See https://github.com/makerdao/dss/blob/master/DEVELOPING.m
-
-    /// @dev Sample sell quotes from Maker PSM
-    function sampleSellsFromMakerPsm(
-        MakerPsmInfo memory psmInfo,
-        address takerToken,
-        address makerToken,
-        uint256[] memory takerTokenAmounts
-    )
-        public
-        view
-        returns (uint256[] memory makerTokenAmounts)
-    {
-        _assertValidPair(makerToken, takerToken);
-        IPSM psm = IPSM(psmInfo.psmAddress);
-        IVAT vat = IVAT(psm.vat());
-
-
-        uint256 numSamples = takerTokenAmounts.length;
-        makerTokenAmounts = new uint256[](numSamples);
-
-        if (makerToken != psm.dai() && takerToken != psm.dai()) {
-            return makerTokenAmounts;
-        }
-
-        for (uint256 i = 0; i < numSamples; i++) {
-            uint256 buyAmount = _samplePSMSell(psmInfo, makerToken, takerToken, takerTokenAmounts[i], psm, vat);
-
-            if (buyAmount == 0) {
-                break;
-            }
-            makerTokenAmounts[i] = buyAmount;
-        }
-    }
-
-    function sampleBuysFromMakerPsm(
-        MakerPsmInfo memory psmInfo,
-        address takerToken,
-        address makerToken,
-        uint256[] memory makerTokenAmounts
-    )
-        public
-        view
-        returns (uint256[] memory takerTokenAmounts)
-    {
-        _assertValidPair(makerToken, takerToken);
-        IPSM psm = IPSM(psmInfo.psmAddress);
-        IVAT vat = IVAT(psm.vat());
-
-        uint256 numSamples = makerTokenAmounts.length;
-        takerTokenAmounts = new uint256[](numSamples);
-        if (makerToken != psm.dai() && takerToken != psm.dai()) {
-            return takerTokenAmounts;
-        }
-
-        for (uint256 i = 0; i < numSamples; i++) {
-            uint256 sellAmount = _samplePSMBuy(psmInfo, makerToken, takerToken, makerTokenAmounts[i], psm, vat);
-
-            if (sellAmount == 0) {
-                break;
-            }
-
-            takerTokenAmounts[i] = sellAmount;
-        }
-
-    }
-
-    function _samplePSMSell(MakerPsmInfo memory psmInfo, address makerToken, address takerToken, uint256 takerTokenAmount, IPSM psm, IVAT vat)
-        private
-        view
-        returns (uint256)
-    {
-        (uint256 totalDebtInWad,,, uint256 debtCeilingInRad, uint256 debtFloorInRad) = vat.ilks(psmInfo.ilkIdentifier);
-        uint256 gemTokenBaseUnit = uint256(1e6);
-
-        if (takerToken == psmInfo.gemTokenAddress) {
-            // Simulate sellGem
-            // Selling USDC to the PSM, increasing the total debt
-            // Convert USDC 6 decimals to 18 decimals [wad]
-            uint256 takerTokenAmountInWad = takerTokenAmount.safeMul(1e12);
-
-            uint256 newTotalDebtInRad = totalDebtInWad.safeAdd(takerTokenAmountInWad).safeMul(RAY);
-
-            // PSM is too full to fit
-            if (newTotalDebtInRad >= debtCeilingInRad) {
-                return 0;
-            }
-
-            uint256 feeInWad = takerTokenAmountInWad.safeMul(psm.tin()).safeDiv(WAD);
-            uint256 makerTokenAmountInWad = takerTokenAmountInWad.safeSub(feeInWad);
-
-            return makerTokenAmountInWad;
-        } else if (makerToken == psmInfo.gemTokenAddress) {
-            // Simulate buyGem
-            // Buying USDC from the PSM, decreasing the total debt
-            // Selling DAI for USDC, already in 18 decimals [wad]
-            uint256 takerTokenAmountInWad = takerTokenAmount;
-            if (takerTokenAmountInWad > totalDebtInWad) {
-                return 0;
-            }
-            uint256 newTotalDebtInRad = totalDebtInWad.safeSub(takerTokenAmountInWad).safeMul(RAY);
-
-            // PSM is empty, not enough USDC to buy from it
-            if (newTotalDebtInRad <= debtFloorInRad) {
-                return 0;
-            }
-
-            uint256 feeDivisorInWad = WAD.safeAdd(psm.tout()); // eg. 1.001 * 10 ** 18 with 0.1% tout;
-            uint256 makerTokenAmountInGemTokenBaseUnits =  takerTokenAmountInWad.safeMul(gemTokenBaseUnit).safeDiv(feeDivisorInWad);
-
-            return makerTokenAmountInGemTokenBaseUnits;
-        }
-
-        return 0;
-    }
-
-    function _samplePSMBuy(MakerPsmInfo memory psmInfo, address makerToken, address takerToken, uint256 makerTokenAmount, IPSM psm, IVAT vat)
-        private
-        view
-        returns (uint256)
-    {
-        (uint256 totalDebtInWad,,, uint256 debtCeilingInRad, uint256 debtFloorInRad) = vat.ilks(psmInfo.ilkIdentifier);
-
-        if (takerToken == psmInfo.gemTokenAddress) {
-            // Simulate sellGem
-            // Selling USDC to the PSM, increasing the total debt
-            uint256 makerTokenAmountInWad = makerTokenAmount;
-            uint256 feeDivisorInWad = WAD.safeSub(psm.tin()); // eg. 0.999 * 10 ** 18 with 0.1% tin;
-            uint256 takerTokenAmountInWad = makerTokenAmountInWad.safeMul(WAD).safeDiv(feeDivisorInWad);
-            uint256 newTotalDebtInRad = totalDebtInWad.safeAdd(takerTokenAmountInWad).safeMul(RAY);
-
-            // PSM is too full to fit
-            if (newTotalDebtInRad >= debtCeilingInRad) {
-                return 0;
-            }
-
-            uint256 takerTokenAmountInGemInGemBaseUnits = (takerTokenAmountInWad.safeDiv(1e12)).safeAdd(1); // Add 1 to deal with cut off decimals converting to lower decimals
-
-            return takerTokenAmountInGemInGemBaseUnits;
-        } else if (makerToken == psmInfo.gemTokenAddress) {
-            // Simulate buyGem
-            // Buying USDC from the PSM, decreasing the total debt
-            uint256 makerTokenAmountInWad = makerTokenAmount.safeMul(1e12);
-            uint256 feeMultiplierInWad = WAD.safeAdd(psm.tout()); // eg. 1.001 * 10 ** 18 with 0.1% tout;
-            uint256 takerTokenAmountInWad =  makerTokenAmountInWad.safeMul(feeMultiplierInWad).safeDiv(WAD);
-            if (takerTokenAmountInWad > totalDebtInWad) {
-                return 0;
-            }
-            uint256 newTotalDebtInRad = totalDebtInWad.safeSub(takerTokenAmountInWad).safeMul(RAY);
-
-            // PSM is empty, not enough USDC to buy
-            if (newTotalDebtInRad <= debtFloorInRad) {
-                return 0;
-            }
-
-
-            return takerTokenAmountInWad;
-        }
-
-        return 0;
-    }
-
-}
--- a/packages/asset-swapper/contracts/src/MooniswapSampler.sol
+++ b/packages/asset-swapper/contracts/src/MooniswapSampler.sol
@@ -1,169 +0,0 @@
-// SPDX-License-Identifier: Apache-2.0
-/*
-
-  Copyright 2020 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 ^0.6;
-pragma experimental ABIEncoderV2;
-
-import "./interfaces/IMooniswap.sol";
-import "./ApproximateBuys.sol";
-import "./SamplerUtils.sol";
-
-
-contract MooniswapSampler is
-    SamplerUtils,
-    ApproximateBuys
-{
-    /// @dev Gas limit for Mooniswap calls.
-    uint256 constant private MOONISWAP_CALL_GAS = 150e3; // 150k
-
-    /// @dev Sample sell quotes from Mooniswap.
-    /// @param registry Address of the Mooniswap Registry.
-    /// @param takerToken Address of the taker token (what to sell).
-    /// @param makerToken Address of the maker token (what to buy).
-    /// @param takerTokenAmounts Taker token sell amount for each sample.
-    /// @return pool The contract address for the pool
-    /// @return makerTokenAmounts Maker amounts bought at each taker token
-    ///         amount.
-    function sampleSellsFromMooniswap(
-        address registry,
-        address takerToken,
-        address makerToken,
-        uint256[] memory takerTokenAmounts
-    )
-        public
-        view
-        returns (IMooniswap pool, uint256[] memory makerTokenAmounts)
-    {
-        _assertValidPair(makerToken, takerToken);
-        uint256 numSamples = takerTokenAmounts.length;
-        makerTokenAmounts = new uint256[](numSamples);
-
-        for (uint256 i = 0; i < numSamples; i++) {
-            uint256 buyAmount = sampleSingleSellFromMooniswapPool(
-                registry,
-                takerToken,
-                makerToken,
-                takerTokenAmounts[i]
-            );
-            makerTokenAmounts[i] = buyAmount;
-            // Break early if there are 0 amounts
-            if (makerTokenAmounts[i] == 0) {
-                break;
-            }
-        }
-
-        pool = IMooniswap(
-            IMooniswapRegistry(registry).pools(takerToken, makerToken)
-        );
-    }
-
-    function sampleSingleSellFromMooniswapPool(
-        address registry,
-        address mooniswapTakerToken,
-        address mooniswapMakerToken,
-        uint256 takerTokenAmount
-    )
-        public
-        view
-        returns (uint256)
-    {
-        // Find the pool for the pair.
-        IMooniswap pool = IMooniswap(
-            IMooniswapRegistry(registry).pools(mooniswapTakerToken, mooniswapMakerToken)
-        );
-        // If there is no pool then return early
-        if (address(pool) == address(0)) {
-            return 0;
-        }
-        uint256 poolBalance = mooniswapTakerToken == address(0)
-            ? address(pool).balance
-            : IERC20TokenV06(mooniswapTakerToken).balanceOf(address(pool));
-        // If the pool balance is smaller than the sell amount
-        // don't sample to avoid multiplication overflow in buys
-        if (poolBalance < takerTokenAmount) {
-            return 0;
-        }
-        try
-            pool.getReturn
-                {gas: MOONISWAP_CALL_GAS}
-                (mooniswapTakerToken, mooniswapMakerToken, takerTokenAmount)
-            returns (uint256 amount)
-        {
-            return amount;
-        } catch (bytes memory) {
-            // Swallow failures, leaving all results as zero.
-            return 0;
-        }
-    }
-
-    /// @dev Sample buy quotes from Mooniswap.
-    /// @param registry Address of the Mooniswap Registry.
-    /// @param takerToken Address of the taker token (what to sell).
-    /// @param makerToken Address of the maker token (what to buy).
-    /// @param makerTokenAmounts Maker token sell amount for each sample.
-    /// @return pool The contract address for the pool
-    /// @return takerTokenAmounts Taker amounts sold at each maker token
-    ///         amount.
-    function sampleBuysFromMooniswap(
-        address registry,
-        address takerToken,
-        address makerToken,
-        uint256[] memory makerTokenAmounts
-    )
-        public
-        view
-        returns (IMooniswap pool, uint256[] memory takerTokenAmounts)
-    {
-        _assertValidPair(makerToken, takerToken);
-        uint256 numSamples = makerTokenAmounts.length;
-        takerTokenAmounts = new uint256[](numSamples);
-
-        takerTokenAmounts = _sampleApproximateBuys(
-            ApproximateBuyQuoteOpts({
-                makerTokenData: abi.encode(registry, makerToken),
-                takerTokenData: abi.encode(registry, takerToken),
-                getSellQuoteCallback: _sampleSellForApproximateBuyFromMooniswap
-            }),
-            makerTokenAmounts
-        );
-
-        pool = IMooniswap(
-            IMooniswapRegistry(registry).pools(takerToken, makerToken)
-        );
-    }
-
-    function _sampleSellForApproximateBuyFromMooniswap(
-        bytes memory takerTokenData,
-        bytes memory makerTokenData,
-        uint256 sellAmount
-    )
-        private
-        view
-        returns (uint256 buyAmount)
-    {
-        (address registry, address mooniswapTakerToken) = abi.decode(takerTokenData, (address, address));
-        (address _registry, address mooniswapMakerToken) = abi.decode(makerTokenData, (address, address));
-        return sampleSingleSellFromMooniswapPool(
-            registry,
-            mooniswapTakerToken,
-            mooniswapMakerToken,
-            sellAmount
-        );
-    }
-}
--- a/packages/asset-swapper/contracts/src/MultiBridgeSampler.sol
+++ b/packages/asset-swapper/contracts/src/MultiBridgeSampler.sol
@@ -1,82 +0,0 @@
-// SPDX-License-Identifier: Apache-2.0
-/*
-
-  Copyright 2020 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 ^0.6;
-pragma experimental ABIEncoderV2;
-
-import "./interfaces/IMultiBridge.sol";
-
-
-contract MultiBridgeSampler {
-
-    /// @dev Default gas limit for multibridge calls.
-    uint256 constant private DEFAULT_CALL_GAS = 400e3; // 400k
-
-    /// @dev Sample sell quotes from MultiBridge.
-    /// @param multibridge Address of the MultiBridge contract.
-    /// @param takerToken Address of the taker token (what to sell).
-    /// @param intermediateToken The address of the intermediate token to
-    ///        use in an indirect route.
-    /// @param makerToken Address of the maker token (what to buy).
-    /// @param takerTokenAmounts Taker token sell amount for each sample.
-    /// @return makerTokenAmounts Maker amounts bought at each taker token
-    ///         amount.
-    function sampleSellsFromMultiBridge(
-        address multibridge,
-        address takerToken,
-        address intermediateToken,
-        address makerToken,
-        uint256[] memory takerTokenAmounts
-    )
-        public
-        view
-        returns (uint256[] memory makerTokenAmounts)
-    {
-        // Initialize array of maker token amounts.
-        uint256 numSamples = takerTokenAmounts.length;
-        makerTokenAmounts = new uint256[](numSamples);
-
-        // If no address provided, return all zeros.
-        if (multibridge == address(0)) {
-            return makerTokenAmounts;
-        }
-
-        for (uint256 i = 0; i < numSamples; i++) {
-            (bool didSucceed, bytes memory resultData) =
-                multibridge.staticcall.gas(DEFAULT_CALL_GAS)(
-                    abi.encodeWithSelector(
-                        IMultiBridge(0).getSellQuote.selector,
-                        takerToken,
-                        intermediateToken,
-                        makerToken,
-                        takerTokenAmounts[i]
-                    ));
-            uint256 buyAmount = 0;
-            if (didSucceed) {
-                buyAmount = abi.decode(resultData, (uint256));
-            }
-            // Exit early if the amount is too high for the source to serve
-            if (buyAmount == 0) {
-                break;
-            }
-
-            makerTokenAmounts[i] = buyAmount;
-        }
-    }
-}
--- a/packages/asset-swapper/contracts/src/NativeOrderSampler.sol
+++ b/packages/asset-swapper/contracts/src/NativeOrderSampler.sol
@@ -1,239 +0,0 @@
-// SPDX-License-Identifier: Apache-2.0
-/*
-
-  Copyright 2021 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 ^0.6;
-pragma experimental ABIEncoderV2;
-
-import "@0x/contracts-erc20/contracts/src/v06/LibERC20TokenV06.sol";
-import "@0x/contracts-utils/contracts/src/v06/LibMathV06.sol";
-import "@0x/contracts-utils/contracts/src/v06/LibBytesV06.sol";
-import "@0x/contracts-utils/contracts/src/v06/LibSafeMathV06.sol";
-
-
-interface IExchange {
-
-    enum OrderStatus {
-        INVALID,
-        FILLABLE,
-        FILLED,
-        CANCELLED,
-        EXPIRED
-    }
-
-    /// @dev A standard OTC or OO limit order.
-    struct LimitOrder {
-        IERC20TokenV06 makerToken;
-        IERC20TokenV06 takerToken;
-        uint128 makerAmount;
-        uint128 takerAmount;
-        uint128 takerTokenFeeAmount;
-        address maker;
-        address taker;
-        address sender;
-        address feeRecipient;
-        bytes32 pool;
-        uint64 expiry;
-        uint256 salt;
-    }
-
-    /// @dev An RFQ limit order.
-    struct RfqOrder {
-        IERC20TokenV06 makerToken;
-        IERC20TokenV06 takerToken;
-        uint128 makerAmount;
-        uint128 takerAmount;
-        address maker;
-        address taker;
-        address txOrigin;
-        bytes32 pool;
-        uint64 expiry;
-        uint256 salt;
-    }
-
-    /// @dev Info on a limit or RFQ order.
-    struct OrderInfo {
-        bytes32 orderHash;
-        OrderStatus status;
-        uint128 takerTokenFilledAmount;
-    }
-
-    /// @dev Allowed signature types.
-    enum SignatureType {
-        ILLEGAL,
-        INVALID,
-        EIP712,
-        ETHSIGN
-    }
-
-    /// @dev Encoded EC signature.
-    struct Signature {
-        // How to validate the signature.
-        SignatureType signatureType;
-        // EC Signature data.
-        uint8 v;
-        // EC Signature data.
-        bytes32 r;
-        // EC Signature data.
-        bytes32 s;
-    }
-
-    /// @dev Get the order info for a limit order.
-    /// @param order The limit order.
-    /// @return orderInfo Info about the order.
-    function getLimitOrderInfo(LimitOrder memory order)
-        external
-        view
-        returns (OrderInfo memory orderInfo);
-
-    /// @dev Get order info, fillable amount, and signature validity for a limit order.
-    ///      Fillable amount is determined using balances and allowances of the maker.
-    /// @param order The limit order.
-    /// @param signature The order signature.
-    /// @return orderInfo Info about the order.
-    /// @return actualFillableTakerTokenAmount How much of the order is fillable
-    ///         based on maker funds, in taker tokens.
-    /// @return isSignatureValid Whether the signature is valid.
-    function getLimitOrderRelevantState(
-        LimitOrder memory order,
-        Signature calldata signature
-    )
-        external
-        view
-        returns (
-            OrderInfo memory orderInfo,
-            uint128 actualFillableTakerTokenAmount,
-            bool isSignatureValid
-        );
-}
-
-contract NativeOrderSampler {
-    using LibSafeMathV06 for uint256;
-    using LibBytesV06 for bytes;
-
-    /// @dev Gas limit for calls to `getOrderFillableTakerAmount()`.
-    uint256 constant internal DEFAULT_CALL_GAS = 200e3; // 200k
-
-    /// @dev Queries the fillable taker asset amounts of native orders.
-    ///      Effectively ignores orders that have empty signatures or
-    ///      maker/taker asset amounts (returning 0).
-    /// @param orders Native limit orders to query.
-    /// @param orderSignatures Signatures for each respective order in `orders`.
-    /// @param exchange The V4 exchange.
-    /// @return orderFillableTakerAssetAmounts How much taker asset can be filled
-    ///         by each order in `orders`.
-    function getLimitOrderFillableTakerAssetAmounts(
-        IExchange.LimitOrder[] memory orders,
-        IExchange.Signature[] memory orderSignatures,
-        IExchange exchange
-    )
-        public
-        view
-        returns (uint256[] memory orderFillableTakerAssetAmounts)
-    {
-        orderFillableTakerAssetAmounts = new uint256[](orders.length);
-        for (uint256 i = 0; i != orders.length; i++) {
-            try
-                this.getLimitOrderFillableTakerAmount
-                    {gas: DEFAULT_CALL_GAS}
-                    (
-                       orders[i],
-                       orderSignatures[i],
-                       exchange
-                    )
-                returns (uint256 amount)
-            {
-                orderFillableTakerAssetAmounts[i] = amount;
-            } catch (bytes memory) {
-                // Swallow failures, leaving all results as zero.
-                orderFillableTakerAssetAmounts[i] = 0;
-            }
-        }
-    }
-
-    /// @dev Queries the fillable taker asset amounts of native orders.
-    ///      Effectively ignores orders that have empty signatures or
-    /// @param orders Native orders to query.
-    /// @param orderSignatures Signatures for each respective order in `orders`.
-    /// @param exchange The V4 exchange.
-    /// @return orderFillableMakerAssetAmounts How much maker asset can be filled
-    ///         by each order in `orders`.
-    function getLimitOrderFillableMakerAssetAmounts(
-        IExchange.LimitOrder[] memory orders,
-        IExchange.Signature[] memory orderSignatures,
-        IExchange exchange
-    )
-        public
-        view
-        returns (uint256[] memory orderFillableMakerAssetAmounts)
-    {
-        orderFillableMakerAssetAmounts = getLimitOrderFillableTakerAssetAmounts(
-            orders,
-            orderSignatures,
-            exchange
-        );
-        // `orderFillableMakerAssetAmounts` now holds taker asset amounts, so
-        // convert them to maker asset amounts.
-        for (uint256 i = 0; i < orders.length; ++i) {
-            if (orderFillableMakerAssetAmounts[i] != 0) {
-                orderFillableMakerAssetAmounts[i] = LibMathV06.getPartialAmountCeil(
-                    orderFillableMakerAssetAmounts[i],
-                    orders[i].takerAmount,
-                    orders[i].makerAmount
-                );
-            }
-        }
-    }
-
-    /// @dev Get the fillable taker amount of an order, taking into account
-    ///      order state, maker fees, and maker balances.
-    function getLimitOrderFillableTakerAmount(
-        IExchange.LimitOrder memory order,
-        IExchange.Signature memory signature,
-        IExchange exchange
-    )
-        virtual
-        public
-        view
-        returns (uint256 fillableTakerAmount)
-    {
-        if (signature.signatureType == IExchange.SignatureType.ILLEGAL ||
-            signature.signatureType == IExchange.SignatureType.INVALID ||
-            order.makerAmount == 0 ||
-            order.takerAmount == 0)
-        {
-            return 0;
-        }
-
-        (
-            IExchange.OrderInfo memory orderInfo,
-            uint128 remainingFillableTakerAmount,
-            bool isSignatureValid
-        ) = exchange.getLimitOrderRelevantState(order, signature);
-
-        if (
-              orderInfo.status != IExchange.OrderStatus.FILLABLE ||
-              !isSignatureValid ||
-              order.makerToken == IERC20TokenV06(0)
-            ) {
-            return 0;
-        }
-
-        fillableTakerAmount = uint256(remainingFillableTakerAmount);
-    }
-}
--- a/packages/asset-swapper/contracts/src/SamplerUtils.sol
+++ b/packages/asset-swapper/contracts/src/SamplerUtils.sol
@@ -1,58 +0,0 @@
-// SPDX-License-Identifier: Apache-2.0
-/*
-
-  Copyright 2020 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 ^0.6;
-pragma experimental ABIEncoderV2;
-
-import "@0x/contracts-erc20/contracts/src/v06/LibERC20TokenV06.sol";
-
-
-contract SamplerUtils {
-
-    /// @dev Overridable way to get token decimals.
-    /// @param tokenAddress Address of the token.
-    /// @return decimals The decimal places for the token.
-    function _getTokenDecimals(address tokenAddress)
-        virtual
-        internal
-        view
-        returns (uint8 decimals)
-    {
-        return LibERC20TokenV06.compatDecimals(IERC20TokenV06(tokenAddress));
-    }
-
-    function _toSingleValueArray(uint256 v)
-        internal
-        pure
-        returns (uint256[] memory arr)
-    {
-        arr = new uint256[](1);
-        arr[0] = v;
-    }
-
-    /// @dev Assert that the tokens in a trade pair are valid.
-    /// @param makerToken Address of the maker token.
-    /// @param takerToken Address of the taker token.
-    function _assertValidPair(address makerToken, address takerToken)
-        internal
-        pure
-    {
-        require(makerToken != takerToken, "ERC20BridgeSampler/INVALID_TOKEN_PAIR");
-    }
-}
--- a/packages/asset-swapper/contracts/src/ShellSampler.sol
+++ b/packages/asset-swapper/contracts/src/ShellSampler.sol
@@ -1,126 +0,0 @@
-// SPDX-License-Identifier: Apache-2.0
-/*
-
-  Copyright 2020 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 ^0.6;
-pragma experimental ABIEncoderV2;
-
-import "./ApproximateBuys.sol";
-import "./interfaces/IShell.sol";
-import "./SamplerUtils.sol";
-
-
-contract ShellSampler is
-    SamplerUtils,
-    ApproximateBuys
-{
-
-    struct ShellInfo {
-        address poolAddress;
-    }
-
-    /// @dev Default gas limit for Shell calls.
-    uint256 constant private DEFAULT_CALL_GAS = 300e3; // 300k
-
-    /// @dev Sample sell quotes from the Shell pool contract
-    /// @param pool Address of the Shell pool contract
-    /// @param takerToken Address of the taker token (what to sell).
-    /// @param makerToken Address of the maker token (what to buy).
-    /// @param takerTokenAmounts Taker token sell amount for each sample.
-    /// @return makerTokenAmounts Maker amounts bought at each taker token
-    ///         amount.
-    function sampleSellsFromShell(
-        address pool,
-        address takerToken,
-        address makerToken,
-        uint256[] memory takerTokenAmounts
-    )
-        public
-        view
-        returns (uint256[] memory makerTokenAmounts)
-    {
-        // Initialize array of maker token amounts.
-        uint256 numSamples = takerTokenAmounts.length;
-        makerTokenAmounts = new uint256[](numSamples);
-
-        for (uint256 i = 0; i < numSamples; i++) {
-            try
-                IShell(pool).viewOriginSwap
-                    {gas: DEFAULT_CALL_GAS}
-                    (takerToken, makerToken, takerTokenAmounts[i])
-                returns (uint256 amount)
-            {
-                makerTokenAmounts[i] = amount;
-            } catch (bytes memory) {
-                // Swallow failures, leaving all results as zero.
-                break;
-            }
-        }
-    }
-
-    /// @dev Sample buy quotes from Shell pool contract
-    /// @param pool Address of the Shell pool contract
-    /// @param takerToken Address of the taker token (what to sell).
-    /// @param makerToken Address of the maker token (what to buy).
-    /// @param makerTokenAmounts Maker token buy amount for each sample.
-    /// @return takerTokenAmounts Taker amounts sold at each maker token
-    ///         amount.
-    function sampleBuysFromShell(
-        address pool,
-        address takerToken,
-        address makerToken,
-        uint256[] memory makerTokenAmounts
-    )
-        public
-        view
-        returns (uint256[] memory takerTokenAmounts)
-    {
-        return _sampleApproximateBuys(
-            ApproximateBuyQuoteOpts({
-                makerTokenData: abi.encode(makerToken, pool),
-                takerTokenData: abi.encode(takerToken, pool),
-                getSellQuoteCallback: _sampleSellForApproximateBuyFromShell
-            }),
-            makerTokenAmounts
-        );
-    }
-
-    function _sampleSellForApproximateBuyFromShell(
-        bytes memory takerTokenData,
-        bytes memory makerTokenData,
-        uint256 sellAmount
-    )
-        private
-        view
-        returns (uint256 buyAmount)
-    {
-        (address takerToken, address pool) = abi.decode(takerTokenData, (address, address));
-        (address makerToken) = abi.decode(makerTokenData, (address));
-
-        try
-            this.sampleSellsFromShell
-                (pool, takerToken, makerToken, _toSingleValueArray(sellAmount))
-            returns (uint256[] memory amounts)
-        {
-            return amounts[0];
-        } catch (bytes memory) {
-            // Swallow failures, leaving all results as zero.
-            return 0;
-        }
-    }
-}
--- a/packages/asset-swapper/contracts/src/SmoothySampler.sol
+++ b/packages/asset-swapper/contracts/src/SmoothySampler.sol
@@ -1,156 +0,0 @@
-// SPDX-License-Identifier: Apache-2.0
-/*
-
-  Copyright 2020 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 ^0.6;
-pragma experimental ABIEncoderV2;
-
-// import "./interfaces/ISmoothy.sol";
-import "./ApproximateBuys.sol";
-import "./SamplerUtils.sol";
-import "./interfaces/ISmoothy.sol";
-
-contract SmoothySampler is
-    SamplerUtils,
-    ApproximateBuys
-{
-    /// @dev Information for sampling from smoothy sources.
-    struct SmoothyInfo {
-        address poolAddress;
-        bytes4 sellQuoteFunctionSelector;
-        bytes4 buyQuoteFunctionSelector;
-    }
-
-    /// @dev Base gas limit for Smoothy calls.
-    uint256 constant private SMOOTHY_CALL_GAS = 600e3;
-
-    /// @dev Sample sell quotes from Smoothy.
-    /// @param smoothyInfo Smoothy information specific to this token pair.
-    /// @param fromTokenIdx Index of the taker token (what to sell).
-    /// @param toTokenIdx Index of the maker token (what to buy).
-    /// @param takerTokenAmounts Taker token sell amount for each sample.
-    /// @return makerTokenAmounts Maker amounts bought at each taker token
-    ///         amount.
-    function sampleSellsFromSmoothy(
-        SmoothyInfo memory smoothyInfo,
-        int128 fromTokenIdx,
-        int128 toTokenIdx,
-        uint256[] memory takerTokenAmounts
-    )
-        public
-        view
-        returns (uint256[] memory makerTokenAmounts)
-    {
-        // Basically a Curve fork
-
-        // Smoothy only keep a percentage of its tokens available in reserve
-        uint256 poolReserveMakerAmount = ISmoothy(smoothyInfo.poolAddress).getBalance(uint256(toTokenIdx)) -
-                                         ISmoothy(smoothyInfo.poolAddress)._yBalances(uint256(toTokenIdx));
-        (, , , uint256 decimals) = ISmoothy(smoothyInfo.poolAddress).getTokenStats(uint256(toTokenIdx));
-        poolReserveMakerAmount = poolReserveMakerAmount/(10**(18-decimals));
-
-        uint256 numSamples = takerTokenAmounts.length;
-        makerTokenAmounts = new uint256[](numSamples);
-        for (uint256 i = 0; i < numSamples; i++) {
-            (bool didSucceed, bytes memory resultData) =
-                smoothyInfo.poolAddress.staticcall.gas(SMOOTHY_CALL_GAS)(
-                    abi.encodeWithSelector(
-                        smoothyInfo.sellQuoteFunctionSelector,
-                        fromTokenIdx,
-                        toTokenIdx,
-                        takerTokenAmounts[i]
-                    ));
-            uint256 buyAmount = 0;
-            if (didSucceed) {
-                buyAmount = abi.decode(resultData, (uint256));
-            }
-
-            // Make sure the quoted buyAmount is available in the pool reserve
-            if (buyAmount >= poolReserveMakerAmount) {
-                // Assign pool reserve amount for all higher samples to break early
-                for (uint256 j = i; j < numSamples; j++) {
-                    makerTokenAmounts[j] = poolReserveMakerAmount;
-                }
-                break;
-            } else {
-                makerTokenAmounts[i] = buyAmount;
-            }
-
-            // Break early if there are 0 amounts
-            if (makerTokenAmounts[i] == 0) {
-                break;
-            }
-        }
-    }
-
-    /// @dev Sample buy quotes from Smoothy.
-    /// @param smoothyInfo Smoothy information specific to this token pair.
-    /// @param fromTokenIdx Index of the taker token (what to sell).
-    /// @param toTokenIdx Index of the maker token (what to buy).
-    /// @param makerTokenAmounts Maker token buy amount for each sample.
-    /// @return takerTokenAmounts Taker amounts sold at each maker token
-    ///         amount.
-    function sampleBuysFromSmoothy(
-        SmoothyInfo memory smoothyInfo,
-        int128 fromTokenIdx,
-        int128 toTokenIdx,
-        uint256[] memory makerTokenAmounts
-    )
-        public
-        view
-        returns (uint256[] memory takerTokenAmounts)
-    {
-        // Buys not supported so approximate it.
-        return _sampleApproximateBuys(
-            ApproximateBuyQuoteOpts({
-                makerTokenData: abi.encode(toTokenIdx, smoothyInfo),
-                takerTokenData: abi.encode(fromTokenIdx, smoothyInfo),
-                getSellQuoteCallback: _sampleSellForApproximateBuyFromSmoothy
-            }),
-            makerTokenAmounts
-        );
-    }
-
-    function _sampleSellForApproximateBuyFromSmoothy(
-        bytes memory takerTokenData,
-        bytes memory makerTokenData,
-        uint256 sellAmount
-    )
-        private
-        view
-        returns (uint256 buyAmount)
-    {
-        (int128 takerTokenIdx, SmoothyInfo memory smoothyInfo) =
-            abi.decode(takerTokenData, (int128, SmoothyInfo));
-        (int128 makerTokenIdx) =
-            abi.decode(makerTokenData, (int128));
-        (bool success, bytes memory resultData) =
-            address(this).staticcall(abi.encodeWithSelector(
-                this.sampleSellsFromSmoothy.selector,
-                smoothyInfo,
-                takerTokenIdx,
-                makerTokenIdx,
-                _toSingleValueArray(sellAmount)
-            ));
-        if (!success) {
-            return 0;
-        }
-        // solhint-disable-next-line indent
-        return abi.decode(resultData, (uint256[]))[0];
-    }
-}
--- a/Show More
+++ b/Show More
Author	SHA1	Message	Date
Lawrence Forman	bfed83dbbd	update tools deps	2022-02-26 16:01:17 -05:00
Lawrence Forman	064ac395e3	rebase	2022-02-26 15:20:30 -05:00
Lawrence Forman	0284a0ebe3	fixed multihop buy through multiplex	2022-02-26 15:20:30 -05:00
Lawrence Forman	4f981be613	it builds	2022-02-26 15:20:30 -05:00
Lawrence Forman	493af4a501	continue rebase	2022-02-26 15:20:30 -05:00
Lawrence Forman	0f207cccb6	rebasing against development...	2022-02-26 15:20:30 -05:00
Lawrence Forman	2727dc3968	`@0x/asset-swapper`: hack together basic sampler service integration `@0x/asset-swapper`: use gasCost from sampler service cleanup `@0x/asset-swapper`: Handle per-fill gas cost correctly in more places getting multihop back up + refactors for treating all quotes as n-hop multihop with nice breakdowns get vips working get multiplex working get rfq working remove unused functions fix multihop buys plz work multihop buys multihop buys seem ok now. fetch less samples for multihop legs get quote report and price comparisons working clean up	2022-02-26 15:20:30 -05:00
Github Actions	389ebb5df8	Publish - @0x/asset-swapper@16.49.9	2022-02-24 09:52:41 +00:00
Github Actions	fd9655e9d4	Updated CHANGELOGS & MD docs	2022-02-24 09:52:38 +00:00
Kim Persson	6480aaa189	fix: native order scaling & don't try to route 1 wei trades (it will fail) (#430 ) * feat: scale oversized native orders to quote amount for fake samples * chore: temporarily use private publish neon-router version * fix: short circuit 1 base unit trades to avoid router error * chore: use published version of `neon-router` * chore: add changelog entry for asset-swapper	2022-02-24 10:34:17 +01:00
Github Actions	38969bb0a8	Publish - @0x/contracts-erc20@3.3.26 - @0x/contracts-test-utils@5.4.17 - @0x/contracts-treasury@1.4.9 - @0x/contracts-utils@4.8.7 - @0x/contracts-zero-ex@0.31.0 - @0x/asset-swapper@16.49.8 - @0x/contract-artifacts@3.17.0 - @0x/contract-wrappers@13.19.0 - @0x/migrations@8.1.15 - @0x/protocol-utils@1.11.0	2022-02-22 22:32:24 +00:00
Github Actions	1847ab93af	Updated CHANGELOGS & MD docs	2022-02-22 22:32:20 +00:00
mzhu25	c1177416f5	[Final] ERC721 and ERC1155 Orders (#429 ) * add LibERC721Order.sol * Add ERC721 interface to vendor/ * Add ERC721OrdersFeature interface * Storage lib for ERC721 orders feature * Implement basic functionality for ERC721 orders (buy, sell, cancel, etc) * Add isValidERC721OrderSignature to interface * implement onERC721Received * Implement batchBuyERC721s * left/right orders -> sell/buy orders * Add missing @return comments * Implement matching functions * Use SafeMath where necessary * add rich errors for ERC721OrdersFeature * Add comments * Add presign support for ERC721 orders * Cancel using just the order nonce * Add IERC721OrdersFeature to IZeroEx * Add taker callback * Assembly optimizations in LibERC721Order * Add ERC721Orders TS class * create zero-ex/contracts/test/integration/ and tokens/ directories * TestMintableERC721Token * tmp * address feedback from original PR (#391) * address feedback from original PR * Update contracts/zero-ex/contracts/src/features/ERC721OrdersFeature.sol Co-authored-by: Kim Persson <kimpers@users.noreply.github.com> * address review feedback and improve order parameter naming * Add batchCancel function * Emit order fields in preSign * Fix tests Co-authored-by: Lawrence Forman <me@merklejerk.com> Co-authored-by: Kim Persson <kimpers@users.noreply.github.com> Co-authored-by: Michael Zhu <mchl.zhu.96@gmail.com> * Remove revertIfIncomplete from batchMatch * Sanity check maker address in preSign * ERC1155OrdersFeature contracts * Commence refactor, abstract base contract * ERC721OrdersFeature inherits from NFTOrders * Refactor ERC1155OrdersFeature to inherit from NFTOrders * Fix order hashing * Fix ERC721OrdersFeature tests * Typos * Remove maker address from preSigned mapping * disable dex sampler tests * Refactor TS tooling * Address PR feedback * Rearrange event fields to better align with struct fields * Update comments * update AbiEncoder.create params * Add ERC1155Order to protocol-utils * Add ERC1155OrdersFeeature tests * Bump package versions and regenerate contract wrappers * Add ERC165Feature * NFT orders: address audit findings (#417) * CVF-1: use pragma solidity ^0.6 instead of ^0.6.5 * CVF-11: fix inaccurate comment * CVF-16: Enable taker callbacks for batchBuyERC1155s * CVF-17: use internal call if revertIfIncomplete is true * CVF-21: avoid duplicate SLOAD * CVF-23: merge if statements * CVF-24: Reorder status checks to be consistent with ERC721OrdersFeature * CVF-25: Update unclear comment (canonical hash -> EIP-712 hash) * CVF-31: Document keys of orderState mapping * CVF-45: DRY up fees/properties hashing * CVF-47, CVF-50, CVF-57: calculate properties.length once; hash propertyStructHashArray in-place using assembly * CVF-56: More descriptive names for assembly variables * CVF-71: Update confusing comment about rounding in _payFees * CVF-72: Move ETH assertions outside of loop in _payFees * CVF-74: Move property validation loop to else branch * CVF-82: Update inaccurate comment * CVF-86: Enable taker callbacks for batchBuyERC721s * CVF-87: use internal call if revertIfIncomplete is true * CVF-89: Perform token mismatch checks before stateful operations * CVF-90, CVF-91: Defer ERC20 token mismatch check * CVF-93: Add inline comments for _payFees parameters in matchERC721Orders * CVF-94: Fix comment (Step 7 -> Step 5) * CVF-98: Use binary & operator instead of mod * CVF-99: Update unclear comment (canonical hash -> EIP-712 hash) * CVF-65, CVF-66, CVF-67: Copy params.ethAvailable into local variable; check that ethSpent does not exceed ethAvailable; remove ethAvailable < erc20FillAmount check * CVF-52, CVF-55, CVF-59: calculate fees.length once; hash feeStructHashArray in-place using assembly * CVF-14, CVF-32: OrderState struct; separate storage mapping for 1155 cancellations so orders can be cancelled by nonce * Update changelogs, IZeroEx artifact/wrapper Co-authored-by: Lawrence Forman <lawrence@0xproject.com> Co-authored-by: Lawrence Forman <me@merklejerk.com> Co-authored-by: Kim Persson <kimpers@users.noreply.github.com>	2022-02-22 10:00:22 -08:00
Github Actions	4fdd203211	Publish - @0x/asset-swapper@16.49.7	2022-02-22 12:50:50 +00:00
Github Actions	4bc11776d7	Updated CHANGELOGS & MD docs	2022-02-22 12:50:47 +00:00
Kim Persson	eb12eac5f3	fix: start native orders "samples" at 0 & don't skip neg adj orders (#425 ) * fix: start native orders "samples" at 0 & don't skip neg adj orders * fix: bail on routes with invalid output estimation (no valid route) * chore: bump neon-router version * chore: add asset-swapper changelog entry	2022-02-22 13:31:47 +01:00
Github Actions	5f5b951998	Publish - @0x/asset-swapper@16.49.6	2022-02-17 16:02:38 +00:00
Github Actions	8e90547604	Updated CHANGELOGS & MD docs	2022-02-17 16:02:34 +00:00
Noah Khamliche	fbea74d7ff	remove comments	2022-02-17 10:40:59 -05:00
Noah Khamliche	dcea16bc13	removed ohmv2/dai and ohmv2/weth, routing is the same without the search overhead	2022-02-17 10:40:59 -05:00
Noah Khamliche	d59a074bd7	updated changelog	2022-02-17 10:40:59 -05:00
Noah Khamliche	39cc4f4dbf	fixed btrfly routing to include the ohmV2/dai, ohmV2/btfly, and ohmV2/weth pools	2022-02-17 10:40:59 -05:00
Github Actions	85bcf87af8	Publish - @0x/asset-swapper@16.49.5	2022-02-14 13:12:38 +00:00
Github Actions	a0fe1c610f	Updated CHANGELOGS & MD docs	2022-02-14 13:12:35 +00:00
Kim Persson	5d21af1a0a	fix: 1 base unit output amount being scale down, rounding to 0 output (#422 ) * fix: 1 base unit output amount being scale down, rounding to 0 output * chore: add asset-swapper changelog entry * fix: round scaled output to base units before clamping	2022-02-14 13:54:53 +01:00
Jacob Evans	f6edbd210c	Update protocol docs (#421 ) * Update protocol docs * Added functions * fix table * eligbility section? * Trader.xyz shoutout * Up to	2022-02-11 22:53:49 +10:00
Github Actions	e084807a8f	Publish - @0x/asset-swapper@16.49.4	2022-02-10 15:34:41 +00:00
Github Actions	1c7d512829	Updated CHANGELOGS & MD docs	2022-02-10 15:34:38 +00:00
Kim Persson	df0e0866e4	fix: Revert Improve Uniswap V3 gas schedule (#397 ) (#419 ) * Revert "feat: Improve Uniswap V3 gas schedule (#397)" This reverts commit `84e4819e6e`. * chore: Add changelog entry	2022-02-10 16:15:54 +01:00
Github Actions	9e6efc3676	Publish - @0x/asset-swapper@16.49.3	2022-02-10 12:12:08 +00:00
Github Actions	3aef29dace	Updated CHANGELOGS & MD docs	2022-02-10 12:12:05 +00:00
Kim Persson	9a16e00577	fix: router RFQ underutilization (#413 ) * fix: pass EP overhead to Path & use path comparison all & vip routes * chore: add changelog entry for asset-swapper	2022-02-10 12:55:30 +01:00
Kim Persson	84e4819e6e	feat: Improve Uniswap V3 gas schedule (#397 ) * feat: UniswapV3Sampler use QuoterV2 for sells WIP * feat: UniswapV3Sampler for QuoterV2 buys WIP * refactor: separate logic to remove stack too deep issue * feat: Use initializedTicksCrossed from Uniswap QuoterV2 for gas est. * fix: use Quoter gasUsed instead of estimating gas from pools + ticks * refactor: clean up UniswapV3Sampler & remove old Quoter interface * refactor: unify code for buys and sells while handling stack too deep * fix: use mean gas price from all sample estimating UniV3 gas schedule * fix: fallback to legacy Uniswap V3 gas estimate if we can't get gasUsed * refactor: use named function instead of fat arrow * chore: add asset-swapper changelog entry	2022-02-10 11:16:24 +01:00
Kim Persson	25dd6bc79a	fix: incorrect output scaling when input is less than desired amount (#401 ) * fix: incorrect output scaling when input is less than desired amount * chore: bump fast-abi * chore: add changelog entry for asset-swapper	2022-02-10 10:43:44 +01:00
Jacob Evans	5d2cdb00c2	fix: slippage inconsistency when recalculated in exchange proxy quote consumer (#412 ) * fix: Pass slippage down rather than recalculate due to accuracy * CHANGELOG	2022-02-04 10:37:38 +10:00
Github Actions	0f701f42d3	Publish - @0x/asset-swapper@16.49.2	2022-01-31 18:24:47 +00:00
Github Actions	3e3e82d3f7	Updated CHANGELOGS & MD docs	2022-01-31 18:24:44 +00:00
Lawrence Forman	c57bf86273	Fix ABI encoding error with two hop buys due to applying slippage to uint(-1) values (#410 ) Co-authored-by: Lawrence Forman <me@merklejerk.com>	2022-01-31 12:51:17 -05:00