Publish

- @0x/contracts-asset-proxy@3.7.19
 - @0x/contracts-broker@1.1.37
 - @0x/contracts-coordinator@3.1.38
 - @0x/contracts-dev-utils@1.3.36
 - @0x/contracts-erc1155@2.1.37
 - @0x/contracts-erc20@3.3.16
 - @0x/contracts-erc721@3.1.37
 - @0x/contracts-exchange-forwarder@4.2.38
 - @0x/contracts-exchange-libs@4.3.37
 - @0x/contracts-exchange@3.2.38
 - @0x/contracts-extensions@6.2.32
 - @0x/contracts-integrations@2.7.64
 - @0x/contracts-multisig@4.1.38
 - @0x/contracts-staking@2.0.45
 - @0x/contracts-test-utils@5.4.8
 - @0x/contracts-treasury@1.3.2
 - @0x/contracts-utils@4.7.16
 - @0x/contracts-zero-ex@0.28.0
 - @0x/asset-swapper@16.25.0
 - @0x/contract-wrappers-test@12.2.53
 - @0x/migrations@8.1.1
 - @0x/protocol-utils@1.8.2

.circleci/config.yml

@@ -2,11 +2,11 @@ version: 2.1
 
 jobs:
     build:
-        resource_class: large
+        resource_class: xlarge
         docker:
             - image: node:12
         environment:
-            NODE_OPTIONS: '--max-old-space-size=6442'
+            NODE_OPTIONS: '--max-old-space-size=16384'
         working_directory: ~/repo
         steps:
             - checkout
@@ -18,8 +18,8 @@ jobs:
                   name: yarn
                   command: yarn --frozen-lockfile --ignore-engines install || yarn --frozen-lockfile --ignore-engines install
             - setup_remote_docker
-            - run: yarn build:ci || yarn build:ci || yarn build:ci
-            - run: yarn build:ts || yarn build:ts || yarn build:ts
+            - run: yarn build:ci || yarn build:ci || yarn build:ci || yarn build:ci || yarn build:ci || yarn build:ci
+            - run: yarn build:ts || yarn build:ts || yarn build:ts || yarn build:ts || yarn build:ts || yarn build:ts
             - save_cache:
                   key: repo-{{ .Environment.CIRCLE_SHA1 }}
                   paths:

.prettierrc

@@ -3,5 +3,6 @@
     "tabWidth": 4,
     "singleQuote": true,
     "trailingComma": "all",
-    "bracketSpacing": true
+    "bracketSpacing": true,
+    "arrowParens": "avoid"
 }

ISSUE_TEMPLATE.md

@@ -49,7 +49,6 @@
 | Package | Version |
 | ------: | :------ |
 
-
 <!-- For example:
 |             `0x.js` | 2.0.4   |
 | `Exchange Contract` | v2      |

README.md

@@ -43,12 +43,12 @@ These packages are all under development. See [/contracts/README.md](/contracts/
 #### 0x-specific packages
 
 | Package                                                  | Version                                                                                                                 | Description                                                                                    |
-| -------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------- |
+| -------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------- |
 | [`@0x/contract-addresses`](/packages/contract-addresses) | [![npm](https://img.shields.io/npm/v/@0x/contract-addresses.svg)](https://www.npmjs.com/package/@0x/contract-addresses) | A tiny utility library for getting known deployed contract addresses for a particular network. |
 | [`@0x/contract-wrappers`](/packages/contract-wrappers)   | [![npm](https://img.shields.io/npm/v/@0x/contract-wrappers.svg)](https://www.npmjs.com/package/@0x/contract-wrappers)   | JS/TS wrappers for interacting with the 0x smart contracts                                     |
 | [`@0x/order-utils`](/packages/order-utils)               | [![npm](https://img.shields.io/npm/v/@0x/order-utils.svg)](https://www.npmjs.com/package/@0x/order-utils)               | A set of utilities for generating, parsing, signing and validating 0x orders                   |
 | [`@0x/migrations`](/packages/migrations)                 | [![npm](https://img.shields.io/npm/v/@0x/migrations.svg)](https://www.npmjs.com/package/@0x/migrations)                 | Migration tool for deploying 0x smart contracts on private testnets                            |
-| [`@0x/contract-artifacts`](/packages/contract-artifacts) | [![npm](https://img.shields.io/npm/v/@0x/contract-artifacts.svg)](https://www.npmjs.com/package/@0x/contract-artifacts) | 0x smart contract compilation artifacts                                                        |  |
+| [`@0x/contract-artifacts`](/packages/contract-artifacts) | [![npm](https://img.shields.io/npm/v/@0x/contract-artifacts.svg)](https://www.npmjs.com/package/@0x/contract-artifacts) | 0x smart contract compilation artifacts                                                        |     |
 
 ## Usage
 

contracts/asset-proxy/CHANGELOG.json

@@ -1,4 +1,76 @@
 [
+    {
+        "timestamp": 1629079369,
+        "version": "3.7.19",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1628665757,
+        "version": "3.7.18",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1628225642,
+        "version": "3.7.17",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1624356181,
+        "version": "3.7.16",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1623382456,
+        "version": "3.7.15",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1622609597,
+        "version": "3.7.14",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1621944788,
+        "version": "3.7.13",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1621600614,
+        "version": "3.7.12",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
     {
         "timestamp": 1620214333,
         "version": "3.7.11",

contracts/asset-proxy/CHANGELOG.md

@@ -5,6 +5,38 @@ Edit the package's CHANGELOG.json file only.
 
 CHANGELOG
 
+## v3.7.19 - _August 16, 2021_
+
+    * Dependencies updated
+
+## v3.7.18 - _August 11, 2021_
+
+    * Dependencies updated
+
+## v3.7.17 - _August 6, 2021_
+
+    * Dependencies updated
+
+## v3.7.16 - _June 22, 2021_
+
+    * Dependencies updated
+
+## v3.7.15 - _June 11, 2021_
+
+    * Dependencies updated
+
+## v3.7.14 - _June 2, 2021_
+
+    * Dependencies updated
+
+## v3.7.13 - _May 25, 2021_
+
+    * Dependencies updated
+
+## v3.7.12 - _May 21, 2021_
+
+    * Dependencies updated
+
 ## v3.7.11 - _May 5, 2021_
 
     * Dependencies updated

contracts/asset-proxy/package.json

@@ -1,6 +1,6 @@
 {
     "name": "@0x/contracts-asset-proxy",
-    "version": "3.7.11",
+    "version": "3.7.19",
     "engines": {
         "node": ">=6.12"
     },
@@ -52,10 +52,10 @@
     "homepage": "https://github.com/0xProject/protocol/tree/main/contracts/protocol",
     "devDependencies": {
         "@0x/abi-gen": "^5.6.0",
-        "@0x/contract-wrappers": "^13.16.1",
+        "@0x/contract-wrappers": "^13.17.4",
         "@0x/contracts-gen": "^2.0.38",
-        "@0x/contracts-test-utils": "^5.4.0",
-        "@0x/contracts-utils": "^4.7.8",
+        "@0x/contracts-test-utils": "^5.4.8",
+        "@0x/contracts-utils": "^4.7.16",
         "@0x/dev-utils": "^4.2.7",
         "@0x/sol-compiler": "^4.7.3",
         "@0x/ts-doc-gen": "^0.0.28",
@@ -80,11 +80,11 @@
     },
     "dependencies": {
         "@0x/base-contract": "^6.4.0",
-        "@0x/contracts-erc1155": "^2.1.29",
-        "@0x/contracts-erc20": "^3.3.8",
-        "@0x/contracts-erc721": "^3.1.29",
-        "@0x/contracts-exchange-libs": "^4.3.29",
-        "@0x/order-utils": "^10.4.21",
+        "@0x/contracts-erc1155": "^2.1.37",
+        "@0x/contracts-erc20": "^3.3.16",
+        "@0x/contracts-erc721": "^3.1.37",
+        "@0x/contracts-exchange-libs": "^4.3.37",
+        "@0x/order-utils": "^10.4.28",
         "@0x/types": "^3.3.3",
         "@0x/typescript-typings": "^5.2.0",
         "@0x/utils": "^6.4.3",

contracts/broker/CHANGELOG.json

@@ -1,4 +1,76 @@
 [
+    {
+        "timestamp": 1629079369,
+        "version": "1.1.37",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1628665757,
+        "version": "1.1.36",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1628225642,
+        "version": "1.1.35",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1624356181,
+        "version": "1.1.34",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1623382456,
+        "version": "1.1.33",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1622609597,
+        "version": "1.1.32",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1621944788,
+        "version": "1.1.31",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1621600614,
+        "version": "1.1.30",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
     {
         "timestamp": 1620214333,
         "version": "1.1.29",

contracts/broker/CHANGELOG.md

@@ -5,6 +5,38 @@ Edit the package's CHANGELOG.json file only.
 
 CHANGELOG
 
+## v1.1.37 - _August 16, 2021_
+
+    * Dependencies updated
+
+## v1.1.36 - _August 11, 2021_
+
+    * Dependencies updated
+
+## v1.1.35 - _August 6, 2021_
+
+    * Dependencies updated
+
+## v1.1.34 - _June 22, 2021_
+
+    * Dependencies updated
+
+## v1.1.33 - _June 11, 2021_
+
+    * Dependencies updated
+
+## v1.1.32 - _June 2, 2021_
+
+    * Dependencies updated
+
+## v1.1.31 - _May 25, 2021_
+
+    * Dependencies updated
+
+## v1.1.30 - _May 21, 2021_
+
+    * Dependencies updated
+
 ## v1.1.29 - _May 5, 2021_
 
     * Dependencies updated

contracts/broker/package.json

@@ -1,6 +1,6 @@
 {
     "name": "@0x/contracts-broker",
-    "version": "1.1.29",
+    "version": "1.1.37",
     "engines": {
         "node": ">=6.12"
     },
@@ -52,14 +52,14 @@
     "homepage": "https://github.com/0xProject/protocol/tree/main/contracts/extensions",
     "devDependencies": {
         "@0x/abi-gen": "^5.6.0",
-        "@0x/contracts-asset-proxy": "^3.7.11",
-        "@0x/contracts-erc20": "^3.3.8",
-        "@0x/contracts-erc721": "^3.1.29",
-        "@0x/contracts-exchange": "^3.2.30",
-        "@0x/contracts-exchange-libs": "^4.3.29",
+        "@0x/contracts-asset-proxy": "^3.7.19",
+        "@0x/contracts-erc20": "^3.3.16",
+        "@0x/contracts-erc721": "^3.1.37",
+        "@0x/contracts-exchange": "^3.2.38",
+        "@0x/contracts-exchange-libs": "^4.3.37",
         "@0x/contracts-gen": "^2.0.38",
-        "@0x/contracts-test-utils": "^5.4.0",
-        "@0x/contracts-utils": "^4.7.8",
+        "@0x/contracts-test-utils": "^5.4.8",
+        "@0x/contracts-utils": "^4.7.16",
         "@0x/sol-compiler": "^4.7.3",
         "@0x/ts-doc-gen": "^0.0.28",
         "@0x/tslint-config": "^4.1.4",
@@ -85,7 +85,7 @@
     },
     "dependencies": {
         "@0x/base-contract": "^6.4.0",
-        "@0x/order-utils": "^10.4.21",
+        "@0x/order-utils": "^10.4.28",
         "@0x/typescript-typings": "^5.2.0",
         "@0x/utils": "^6.4.3",
         "ethereum-types": "^3.5.0"

contracts/broker/src/gods_unchained_utils.ts

@@ -7,7 +7,10 @@ export interface GodsUnchainedProperties {
     quality: BigNumber | number;
 }
 
-const propertyDataEncoder = AbiEncoder.create([{ name: 'proto', type: 'uint16' }, { name: 'quality', type: 'uint8' }]);
+const propertyDataEncoder = AbiEncoder.create([
+    { name: 'proto', type: 'uint16' },
+    { name: 'quality', type: 'uint8' },
+]);
 const brokerDataEncoder = AbiEncoder.create([
     { name: 'godsUnchainedAddress', type: 'address' },
     { name: 'validatorAddress', type: 'address' },

contracts/coordinator/CHANGELOG.json

@@ -1,4 +1,76 @@
 [
+    {
+        "timestamp": 1629079369,
+        "version": "3.1.38",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1628665757,
+        "version": "3.1.37",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1628225642,
+        "version": "3.1.36",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1624356181,
+        "version": "3.1.35",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1623382456,
+        "version": "3.1.34",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1622609597,
+        "version": "3.1.33",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1621944788,
+        "version": "3.1.32",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1621600614,
+        "version": "3.1.31",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
     {
         "timestamp": 1620214333,
         "version": "3.1.30",

contracts/coordinator/CHANGELOG.md

@@ -5,6 +5,38 @@ Edit the package's CHANGELOG.json file only.
 
 CHANGELOG
 
+## v3.1.38 - _August 16, 2021_
+
+    * Dependencies updated
+
+## v3.1.37 - _August 11, 2021_
+
+    * Dependencies updated
+
+## v3.1.36 - _August 6, 2021_
+
+    * Dependencies updated
+
+## v3.1.35 - _June 22, 2021_
+
+    * Dependencies updated
+
+## v3.1.34 - _June 11, 2021_
+
+    * Dependencies updated
+
+## v3.1.33 - _June 2, 2021_
+
+    * Dependencies updated
+
+## v3.1.32 - _May 25, 2021_
+
+    * Dependencies updated
+
+## v3.1.31 - _May 21, 2021_
+
+    * Dependencies updated
+
 ## v3.1.30 - _May 5, 2021_
 
     * Dependencies updated

contracts/coordinator/package.json

@@ -1,6 +1,6 @@
 {
     "name": "@0x/contracts-coordinator",
-    "version": "3.1.30",
+    "version": "3.1.38",
     "engines": {
         "node": ">=6.12"
     },
@@ -53,12 +53,12 @@
     "homepage": "https://github.com/0xProject/protocol/tree/main/contracts/extensions",
     "devDependencies": {
         "@0x/abi-gen": "^5.6.0",
-        "@0x/contracts-asset-proxy": "^3.7.11",
-        "@0x/contracts-dev-utils": "^1.3.28",
-        "@0x/contracts-erc20": "^3.3.8",
+        "@0x/contracts-asset-proxy": "^3.7.19",
+        "@0x/contracts-dev-utils": "^1.3.36",
+        "@0x/contracts-erc20": "^3.3.16",
         "@0x/contracts-gen": "^2.0.38",
         "@0x/dev-utils": "^4.2.7",
-        "@0x/order-utils": "^10.4.21",
+        "@0x/order-utils": "^10.4.28",
         "@0x/sol-compiler": "^4.7.3",
         "@0x/ts-doc-gen": "^0.0.28",
         "@0x/tslint-config": "^4.1.4",
@@ -84,10 +84,10 @@
     "dependencies": {
         "@0x/assert": "^3.0.27",
         "@0x/base-contract": "^6.4.0",
-        "@0x/contract-addresses": "^6.1.0",
-        "@0x/contracts-exchange": "^3.2.30",
-        "@0x/contracts-test-utils": "^5.4.0",
-        "@0x/contracts-utils": "^4.7.8",
+        "@0x/contract-addresses": "^6.6.0",
+        "@0x/contracts-exchange": "^3.2.38",
+        "@0x/contracts-test-utils": "^5.4.8",
+        "@0x/contracts-utils": "^4.7.16",
         "@0x/json-schemas": "^6.1.3",
         "@0x/types": "^3.3.3",
         "@0x/typescript-typings": "^5.2.0",

contracts/dev-utils/CHANGELOG.json

@@ -1,4 +1,76 @@
 [
+    {
+        "timestamp": 1629079369,
+        "version": "1.3.36",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1628665757,
+        "version": "1.3.35",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1628225642,
+        "version": "1.3.34",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1624356181,
+        "version": "1.3.33",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1623382456,
+        "version": "1.3.32",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1622609597,
+        "version": "1.3.31",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1621944788,
+        "version": "1.3.30",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1621600614,
+        "version": "1.3.29",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
     {
         "timestamp": 1620214333,
         "version": "1.3.28",

contracts/dev-utils/CHANGELOG.md

@@ -5,6 +5,38 @@ Edit the package's CHANGELOG.json file only.
 
 CHANGELOG
 
+## v1.3.36 - _August 16, 2021_
+
+    * Dependencies updated
+
+## v1.3.35 - _August 11, 2021_
+
+    * Dependencies updated
+
+## v1.3.34 - _August 6, 2021_
+
+    * Dependencies updated
+
+## v1.3.33 - _June 22, 2021_
+
+    * Dependencies updated
+
+## v1.3.32 - _June 11, 2021_
+
+    * Dependencies updated
+
+## v1.3.31 - _June 2, 2021_
+
+    * Dependencies updated
+
+## v1.3.30 - _May 25, 2021_
+
+    * Dependencies updated
+
+## v1.3.29 - _May 21, 2021_
+
+    * Dependencies updated
+
 ## v1.3.28 - _May 5, 2021_
 
     * Dependencies updated

contracts/dev-utils/package.json

@@ -1,6 +1,6 @@
 {
     "name": "@0x/contracts-dev-utils",
-    "version": "1.3.28",
+    "version": "1.3.36",
     "engines": {
         "node": ">=6.12"
     },
@@ -43,10 +43,10 @@
     "devDependencies": {
         "@0x/abi-gen": "^5.6.0",
         "@0x/assert": "^3.0.27",
-        "@0x/contracts-asset-proxy": "^3.7.11",
-        "@0x/contracts-erc20": "^3.3.8",
+        "@0x/contracts-asset-proxy": "^3.7.19",
+        "@0x/contracts-erc20": "^3.3.16",
         "@0x/contracts-gen": "^2.0.38",
-        "@0x/contracts-test-utils": "^5.4.0",
+        "@0x/contracts-test-utils": "^5.4.8",
         "@0x/sol-compiler": "^4.7.3",
         "@0x/ts-doc-gen": "^0.0.28",
         "@0x/tslint-config": "^4.1.4",

contracts/erc1155/CHANGELOG.json

@@ -1,4 +1,76 @@
 [
+    {
+        "timestamp": 1629079369,
+        "version": "2.1.37",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1628665757,
+        "version": "2.1.36",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1628225642,
+        "version": "2.1.35",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1624356181,
+        "version": "2.1.34",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1623382456,
+        "version": "2.1.33",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1622609597,
+        "version": "2.1.32",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1621944788,
+        "version": "2.1.31",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1621600614,
+        "version": "2.1.30",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
     {
         "timestamp": 1620214333,
         "version": "2.1.29",

contracts/erc1155/CHANGELOG.md

@@ -5,6 +5,38 @@ Edit the package's CHANGELOG.json file only.
 
 CHANGELOG
 
+## v2.1.37 - _August 16, 2021_
+
+    * Dependencies updated
+
+## v2.1.36 - _August 11, 2021_
+
+    * Dependencies updated
+
+## v2.1.35 - _August 6, 2021_
+
+    * Dependencies updated
+
+## v2.1.34 - _June 22, 2021_
+
+    * Dependencies updated
+
+## v2.1.33 - _June 11, 2021_
+
+    * Dependencies updated
+
+## v2.1.32 - _June 2, 2021_
+
+    * Dependencies updated
+
+## v2.1.31 - _May 25, 2021_
+
+    * Dependencies updated
+
+## v2.1.30 - _May 21, 2021_
+
+    * Dependencies updated
+
 ## v2.1.29 - _May 5, 2021_
 
     * Dependencies updated

contracts/erc1155/package.json

@@ -1,6 +1,6 @@
 {
     "name": "@0x/contracts-erc1155",
-    "version": "2.1.29",
+    "version": "2.1.37",
     "engines": {
         "node": ">=6.12"
     },
@@ -54,7 +54,7 @@
     "devDependencies": {
         "@0x/abi-gen": "^5.6.0",
         "@0x/contracts-gen": "^2.0.38",
-        "@0x/contracts-utils": "^4.7.8",
+        "@0x/contracts-utils": "^4.7.16",
         "@0x/dev-utils": "^4.2.7",
         "@0x/sol-compiler": "^4.7.3",
         "@0x/ts-doc-gen": "^0.0.28",
@@ -81,7 +81,7 @@
     },
     "dependencies": {
         "@0x/base-contract": "^6.4.0",
-        "@0x/contracts-test-utils": "^5.4.0",
+        "@0x/contracts-test-utils": "^5.4.8",
         "@0x/utils": "^6.4.3",
         "@0x/web3-wrapper": "^7.5.3",
         "lodash": "^4.17.11"

contracts/erc20/CHANGELOG.json

@@ -1,4 +1,77 @@
 [
+    {
+        "timestamp": 1629079369,
+        "version": "3.3.16",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "version": "3.3.15",
+        "changes": [
+            {
+                "note": "Add ethers as a dependency",
+                "pr": 305
+            }
+        ],
+        "timestamp": 1628665757
+    },
+    {
+        "timestamp": 1628225642,
+        "version": "3.3.14",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1624356181,
+        "version": "3.3.13",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1623382456,
+        "version": "3.3.12",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1622609597,
+        "version": "3.3.11",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1621944788,
+        "version": "3.3.10",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1621600614,
+        "version": "3.3.9",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
     {
         "timestamp": 1620214333,
         "version": "3.3.8",

contracts/erc20/CHANGELOG.md

@@ -5,6 +5,38 @@ Edit the package's CHANGELOG.json file only.
 
 CHANGELOG
 
+## v3.3.16 - _August 16, 2021_
+
+    * Dependencies updated
+
+## v3.3.15 - _August 11, 2021_
+
+    * Add ethers as a dependency (#305)
+
+## v3.3.14 - _August 6, 2021_
+
+    * Dependencies updated
+
+## v3.3.13 - _June 22, 2021_
+
+    * Dependencies updated
+
+## v3.3.12 - _June 11, 2021_
+
+    * Dependencies updated
+
+## v3.3.11 - _June 2, 2021_
+
+    * Dependencies updated
+
+## v3.3.10 - _May 25, 2021_
+
+    * Dependencies updated
+
+## v3.3.9 - _May 21, 2021_
+
+    * Dependencies updated
+
 ## v3.3.8 - _May 5, 2021_
 
     * Dependencies updated

contracts/erc20/contracts/src/v06/LibERC20TokenV06.sol

@@ -28,7 +28,7 @@ library LibERC20TokenV06 {
     bytes constant private DECIMALS_CALL_DATA = hex"313ce567";
 
     /// @dev Calls `IERC20TokenV06(token).approve()`.
-    ///      Reverts if the result fails `isSuccessfulResult()` or the call reverts.
+    ///      Reverts if the return data is invalid or the call reverts.
     /// @param token The address of the token contract.
     /// @param spender The address that receives an allowance.
     /// @param allowance The allowance to set.
@@ -49,7 +49,7 @@ library LibERC20TokenV06 {
 
     /// @dev Calls `IERC20TokenV06(token).approve()` and sets the allowance to the
     ///      maximum if the current approval is not already >= an amount.
-    ///      Reverts if the result fails `isSuccessfulResult()` or the call reverts.
+    ///      Reverts if the return data is invalid or the call reverts.
     /// @param token The address of the token contract.
     /// @param spender The address that receives an allowance.
     /// @param amount The minimum allowance needed.
@@ -66,7 +66,7 @@ library LibERC20TokenV06 {
     }
 
     /// @dev Calls `IERC20TokenV06(token).transfer()`.
-    ///      Reverts if the result fails `isSuccessfulResult()` or the call reverts.
+    ///      Reverts if the return data is invalid or the call reverts.
     /// @param token The address of the token contract.
     /// @param to The address that receives the tokens
     /// @param amount Number of tokens to transfer.
@@ -86,7 +86,7 @@ library LibERC20TokenV06 {
     }
 
     /// @dev Calls `IERC20TokenV06(token).transferFrom()`.
-    ///      Reverts if the result fails `isSuccessfulResult()` or the call reverts.
+    ///      Reverts if the return data is invalid or the call reverts.
     /// @param token The address of the token contract.
     /// @param from The owner of the tokens.
     /// @param to The address that receives the tokens
@@ -168,27 +168,6 @@ library LibERC20TokenV06 {
         }
     }
 
-    /// @dev Check if the data returned by a non-static call to an ERC20 token
-    ///      is a successful result. Supported functions are `transfer()`,
-    ///      `transferFrom()`, and `approve()`.
-    /// @param resultData The raw data returned by a non-static call to the ERC20 token.
-    /// @return isSuccessful Whether the result data indicates success.
-    function isSuccessfulResult(bytes memory resultData)
-        internal
-        pure
-        returns (bool isSuccessful)
-    {
-        if (resultData.length == 0) {
-            return true;
-        }
-        if (resultData.length >= 32) {
-            uint256 result = LibBytesV06.readUint256(resultData, 0);
-            if (result == 1) {
-                return true;
-            }
-        }
-    }
-
     /// @dev Executes a call on address `target` with calldata `callData`
     ///      and asserts that either nothing was returned or a single boolean
     ///      was returned equal to `true`.
@@ -201,9 +180,31 @@ library LibERC20TokenV06 {
         private
     {
         (bool didSucceed, bytes memory resultData) = target.call(callData);
-        if (didSucceed && isSuccessfulResult(resultData)) {
+        // Revert if the call reverted.
+        if (!didSucceed) {
+            LibRichErrorsV06.rrevert(resultData);
+        }
+        // If we get back 0 returndata, this may be a non-standard ERC-20 that
+        // does not return a boolean. Check that it at least contains code.
+        if (resultData.length == 0) {
+            uint256 size;
+            assembly { size := extcodesize(target) }
+            require(size > 0, "invalid token address, contains no code");
             return;
         }
+        // If we get back at least 32 bytes, we know the target address
+        // contains code, and we assume it is a token that returned a boolean
+        // success value, which must be true.
+        if (resultData.length >= 32) {
+            uint256 result = LibBytesV06.readUint256(resultData, 0);
+            if (result == 1) {
+                return;
+            } else {
+                LibRichErrorsV06.rrevert(resultData);
+            }
+        }
+        // If 0 < returndatasize < 32, the target is a contract, but not a
+        // valid token.
         LibRichErrorsV06.rrevert(resultData);
     }
 }

contracts/erc20/package.json

@@ -1,6 +1,6 @@
 {
     "name": "@0x/contracts-erc20",
-    "version": "3.3.8",
+    "version": "3.3.16",
     "engines": {
         "node": ">=6.12"
     },
@@ -53,8 +53,8 @@
     "devDependencies": {
         "@0x/abi-gen": "^5.6.0",
         "@0x/contracts-gen": "^2.0.38",
-        "@0x/contracts-test-utils": "^5.4.0",
-        "@0x/contracts-utils": "^4.7.8",
+        "@0x/contracts-test-utils": "^5.4.8",
+        "@0x/contracts-utils": "^4.7.16",
         "@0x/dev-utils": "^4.2.7",
         "@0x/sol-compiler": "^4.7.3",
         "@0x/ts-doc-gen": "^0.0.28",
@@ -82,7 +82,8 @@
         "typescript": "4.2.2"
     },
     "dependencies": {
-        "@0x/base-contract": "^6.4.0"
+        "@0x/base-contract": "^6.4.0",
+        "ethers": "~4.0.4"
     },
     "publishConfig": {
         "access": "public"

contracts/erc721/CHANGELOG.json

@@ -1,4 +1,76 @@
 [
+    {
+        "timestamp": 1629079369,
+        "version": "3.1.37",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1628665757,
+        "version": "3.1.36",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1628225642,
+        "version": "3.1.35",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1624356181,
+        "version": "3.1.34",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1623382456,
+        "version": "3.1.33",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1622609597,
+        "version": "3.1.32",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1621944788,
+        "version": "3.1.31",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1621600614,
+        "version": "3.1.30",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
     {
         "timestamp": 1620214333,
         "version": "3.1.29",

contracts/erc721/CHANGELOG.md

@@ -5,6 +5,38 @@ Edit the package's CHANGELOG.json file only.
 
 CHANGELOG
 
+## v3.1.37 - _August 16, 2021_
+
+    * Dependencies updated
+
+## v3.1.36 - _August 11, 2021_
+
+    * Dependencies updated
+
+## v3.1.35 - _August 6, 2021_
+
+    * Dependencies updated
+
+## v3.1.34 - _June 22, 2021_
+
+    * Dependencies updated
+
+## v3.1.33 - _June 11, 2021_
+
+    * Dependencies updated
+
+## v3.1.32 - _June 2, 2021_
+
+    * Dependencies updated
+
+## v3.1.31 - _May 25, 2021_
+
+    * Dependencies updated
+
+## v3.1.30 - _May 21, 2021_
+
+    * Dependencies updated
+
 ## v3.1.29 - _May 5, 2021_
 
     * Dependencies updated

contracts/erc721/package.json

@@ -1,6 +1,6 @@
 {
     "name": "@0x/contracts-erc721",
-    "version": "3.1.29",
+    "version": "3.1.37",
     "engines": {
         "node": ">=6.12"
     },
@@ -54,8 +54,8 @@
     "devDependencies": {
         "@0x/abi-gen": "^5.6.0",
         "@0x/contracts-gen": "^2.0.38",
-        "@0x/contracts-test-utils": "^5.4.0",
-        "@0x/contracts-utils": "^4.7.8",
+        "@0x/contracts-test-utils": "^5.4.8",
+        "@0x/contracts-utils": "^4.7.16",
         "@0x/dev-utils": "^4.2.7",
         "@0x/sol-compiler": "^4.7.3",
         "@0x/ts-doc-gen": "^0.0.28",

contracts/exchange-forwarder/CHANGELOG.json

@@ -1,4 +1,76 @@
 [
+    {
+        "timestamp": 1629079369,
+        "version": "4.2.38",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1628665757,
+        "version": "4.2.37",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1628225642,
+        "version": "4.2.36",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1624356181,
+        "version": "4.2.35",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1623382456,
+        "version": "4.2.34",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1622609597,
+        "version": "4.2.33",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1621944788,
+        "version": "4.2.32",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1621600614,
+        "version": "4.2.31",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
     {
         "timestamp": 1620214333,
         "version": "4.2.30",

contracts/exchange-forwarder/CHANGELOG.md

@@ -5,6 +5,38 @@ Edit the package's CHANGELOG.json file only.
 
 CHANGELOG
 
+## v4.2.38 - _August 16, 2021_
+
+    * Dependencies updated
+
+## v4.2.37 - _August 11, 2021_
+
+    * Dependencies updated
+
+## v4.2.36 - _August 6, 2021_
+
+    * Dependencies updated
+
+## v4.2.35 - _June 22, 2021_
+
+    * Dependencies updated
+
+## v4.2.34 - _June 11, 2021_
+
+    * Dependencies updated
+
+## v4.2.33 - _June 2, 2021_
+
+    * Dependencies updated
+
+## v4.2.32 - _May 25, 2021_
+
+    * Dependencies updated
+
+## v4.2.31 - _May 21, 2021_
+
+    * Dependencies updated
+
 ## v4.2.30 - _May 5, 2021_
 
     * Dependencies updated

contracts/exchange-forwarder/package.json

@@ -1,6 +1,6 @@
 {
     "name": "@0x/contracts-exchange-forwarder",
-    "version": "4.2.30",
+    "version": "4.2.38",
     "engines": {
         "node": ">=6.12"
     },
@@ -53,18 +53,18 @@
     "homepage": "https://github.com/0xProject/protocol/tree/main/contracts/extensions",
     "devDependencies": {
         "@0x/abi-gen": "^5.6.0",
-        "@0x/contracts-asset-proxy": "^3.7.11",
-        "@0x/contracts-dev-utils": "^1.3.28",
-        "@0x/contracts-erc1155": "^2.1.29",
-        "@0x/contracts-erc20": "^3.3.8",
-        "@0x/contracts-erc721": "^3.1.29",
-        "@0x/contracts-exchange": "^3.2.30",
-        "@0x/contracts-exchange-libs": "^4.3.29",
+        "@0x/contracts-asset-proxy": "^3.7.19",
+        "@0x/contracts-dev-utils": "^1.3.36",
+        "@0x/contracts-erc1155": "^2.1.37",
+        "@0x/contracts-erc20": "^3.3.16",
+        "@0x/contracts-erc721": "^3.1.37",
+        "@0x/contracts-exchange": "^3.2.38",
+        "@0x/contracts-exchange-libs": "^4.3.37",
         "@0x/contracts-gen": "^2.0.38",
-        "@0x/contracts-test-utils": "^5.4.0",
-        "@0x/contracts-utils": "^4.7.8",
+        "@0x/contracts-test-utils": "^5.4.8",
+        "@0x/contracts-utils": "^4.7.16",
         "@0x/dev-utils": "^4.2.7",
-        "@0x/order-utils": "^10.4.21",
+        "@0x/order-utils": "^10.4.28",
         "@0x/sol-compiler": "^4.7.3",
         "@0x/ts-doc-gen": "^0.0.28",
         "@0x/tslint-config": "^4.1.4",

contracts/exchange-libs/CHANGELOG.json

@@ -1,4 +1,76 @@
 [
+    {
+        "timestamp": 1629079369,
+        "version": "4.3.37",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1628665757,
+        "version": "4.3.36",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1628225642,
+        "version": "4.3.35",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1624356181,
+        "version": "4.3.34",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1623382456,
+        "version": "4.3.33",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1622609597,
+        "version": "4.3.32",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1621944788,
+        "version": "4.3.31",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1621600614,
+        "version": "4.3.30",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
     {
         "timestamp": 1620214333,
         "version": "4.3.29",

contracts/exchange-libs/CHANGELOG.md

@@ -5,6 +5,38 @@ Edit the package's CHANGELOG.json file only.
 
 CHANGELOG
 
+## v4.3.37 - _August 16, 2021_
+
+    * Dependencies updated
+
+## v4.3.36 - _August 11, 2021_
+
+    * Dependencies updated
+
+## v4.3.35 - _August 6, 2021_
+
+    * Dependencies updated
+
+## v4.3.34 - _June 22, 2021_
+
+    * Dependencies updated
+
+## v4.3.33 - _June 11, 2021_
+
+    * Dependencies updated
+
+## v4.3.32 - _June 2, 2021_
+
+    * Dependencies updated
+
+## v4.3.31 - _May 25, 2021_
+
+    * Dependencies updated
+
+## v4.3.30 - _May 21, 2021_
+
+    * Dependencies updated
+
 ## v4.3.29 - _May 5, 2021_
 
     * Dependencies updated

contracts/exchange-libs/package.json

@@ -1,6 +1,6 @@
 {
     "name": "@0x/contracts-exchange-libs",
-    "version": "4.3.29",
+    "version": "4.3.37",
     "engines": {
         "node": ">=6.12"
     },
@@ -81,9 +81,9 @@
     },
     "dependencies": {
         "@0x/base-contract": "^6.4.0",
-        "@0x/contracts-test-utils": "^5.4.0",
-        "@0x/contracts-utils": "^4.7.8",
-        "@0x/order-utils": "^10.4.21",
+        "@0x/contracts-test-utils": "^5.4.8",
+        "@0x/contracts-utils": "^4.7.16",
+        "@0x/order-utils": "^10.4.28",
         "@0x/types": "^3.3.3",
         "@0x/typescript-typings": "^5.2.0",
         "@0x/utils": "^6.4.3",

contracts/exchange/CHANGELOG.json

@@ -1,4 +1,76 @@
 [
+    {
+        "timestamp": 1629079369,
+        "version": "3.2.38",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1628665757,
+        "version": "3.2.37",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1628225642,
+        "version": "3.2.36",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1624356181,
+        "version": "3.2.35",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1623382456,
+        "version": "3.2.34",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1622609597,
+        "version": "3.2.33",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1621944788,
+        "version": "3.2.32",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1621600614,
+        "version": "3.2.31",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
     {
         "timestamp": 1620214333,
         "version": "3.2.30",

contracts/exchange/CHANGELOG.md

@@ -5,6 +5,38 @@ Edit the package's CHANGELOG.json file only.
 
 CHANGELOG
 
+## v3.2.38 - _August 16, 2021_
+
+    * Dependencies updated
+
+## v3.2.37 - _August 11, 2021_
+
+    * Dependencies updated
+
+## v3.2.36 - _August 6, 2021_
+
+    * Dependencies updated
+
+## v3.2.35 - _June 22, 2021_
+
+    * Dependencies updated
+
+## v3.2.34 - _June 11, 2021_
+
+    * Dependencies updated
+
+## v3.2.33 - _June 2, 2021_
+
+    * Dependencies updated
+
+## v3.2.32 - _May 25, 2021_
+
+    * Dependencies updated
+
+## v3.2.31 - _May 21, 2021_
+
+    * Dependencies updated
+
 ## v3.2.30 - _May 5, 2021_
 
     * Dependencies updated

contracts/exchange/package.json

@@ -1,6 +1,6 @@
 {
     "name": "@0x/contracts-exchange",
-    "version": "3.2.30",
+    "version": "3.2.38",
     "engines": {
         "node": ">=6.12"
     },
@@ -53,13 +53,13 @@
     "homepage": "https://github.com/0xProject/protocol/tree/main/contracts/protocol",
     "devDependencies": {
         "@0x/abi-gen": "^5.6.0",
-        "@0x/contracts-asset-proxy": "^3.7.11",
-        "@0x/contracts-exchange-libs": "^4.3.29",
+        "@0x/contracts-asset-proxy": "^3.7.19",
+        "@0x/contracts-exchange-libs": "^4.3.37",
         "@0x/contracts-gen": "^2.0.38",
-        "@0x/contracts-multisig": "^4.1.30",
-        "@0x/contracts-staking": "^2.0.37",
-        "@0x/contracts-test-utils": "^5.4.0",
-        "@0x/contracts-utils": "^4.7.8",
+        "@0x/contracts-multisig": "^4.1.38",
+        "@0x/contracts-staking": "^2.0.45",
+        "@0x/contracts-test-utils": "^5.4.8",
+        "@0x/contracts-utils": "^4.7.16",
         "@0x/dev-utils": "^4.2.7",
         "@0x/sol-compiler": "^4.7.3",
         "@0x/ts-doc-gen": "^0.0.28",
@@ -89,11 +89,11 @@
     },
     "dependencies": {
         "@0x/base-contract": "^6.4.0",
-        "@0x/contracts-dev-utils": "^1.3.28",
-        "@0x/contracts-erc1155": "^2.1.29",
-        "@0x/contracts-erc20": "^3.3.8",
-        "@0x/contracts-erc721": "^3.1.29",
-        "@0x/order-utils": "^10.4.21",
+        "@0x/contracts-dev-utils": "^1.3.36",
+        "@0x/contracts-erc1155": "^2.1.37",
+        "@0x/contracts-erc20": "^3.3.16",
+        "@0x/contracts-erc721": "^3.1.37",
+        "@0x/order-utils": "^10.4.28",
         "@0x/utils": "^6.4.3",
         "lodash": "^4.17.11"
     },

contracts/exchange/src/exchange_data_encoder.ts

@@ -13,7 +13,11 @@ export const exchangeDataEncoder = {
                 .getABIEncodedTransactionData();
         } else if (constants.BATCH_FILL_FN_NAMES.indexOf(fnName) !== -1) {
             data = (exchangeInstance as any)
-                [fnName](orders, orders.map(order => order.takerAssetAmount), orders.map(order => order.signature))
+                [fnName](
+                    orders,
+                    orders.map(order => order.takerAssetAmount),
+                    orders.map(order => order.signature),
+                )
                 .getABIEncodedTransactionData();
         } else if (constants.MARKET_FILL_FN_NAMES.indexOf(fnName) !== -1) {
             const fillAsset = /Buy/.test(fnName) ? 'makerAssetAmount' : 'takerAssetAmount';

contracts/exchange/test/reentrancy_tests.ts

@@ -39,7 +39,10 @@ blockchainTests.resets('Reentrancy Tests', env => {
         // Handle tuples.
         if (item.type === 'tuple') {
             const tuple = item as TupleDataItem;
-            return _.zipObject(tuple.components.map(c => c.name), tuple.components.map(createFunctionInputs));
+            return _.zipObject(
+                tuple.components.map(c => c.name),
+                tuple.components.map(createFunctionInputs),
+            );
         }
         // Handle strings.
         if (item.type === 'string') {

contracts/exchange/test/utils/exchange_wrapper.ts

@@ -109,7 +109,11 @@ export class ExchangeWrapper {
         opts: { makerAssetFillAmount: BigNumber; gas?: number; gasPrice?: BigNumber },
     ): Promise<TransactionReceiptWithDecodedLogs> {
         return this.exchangeContract
-            .marketBuyOrdersNoThrow(orders, opts.makerAssetFillAmount, orders.map(signedOrder => signedOrder.signature))
+            .marketBuyOrdersNoThrow(
+                orders,
+                opts.makerAssetFillAmount,
+                orders.map(signedOrder => signedOrder.signature),
+            )
             .awaitTransactionSuccessAsync({ from, gas: opts.gas });
     }
     public async marketSellOrdersFillOrKillAsync(

contracts/extensions/CHANGELOG.json

@@ -1,4 +1,76 @@
 [
+    {
+        "timestamp": 1629079369,
+        "version": "6.2.32",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1628665757,
+        "version": "6.2.31",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1628225642,
+        "version": "6.2.30",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1624356181,
+        "version": "6.2.29",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1623382456,
+        "version": "6.2.28",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1622609597,
+        "version": "6.2.27",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1621944788,
+        "version": "6.2.26",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1621600614,
+        "version": "6.2.25",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
     {
         "timestamp": 1620214333,
         "version": "6.2.24",

contracts/extensions/CHANGELOG.md

@@ -5,6 +5,38 @@ Edit the package's CHANGELOG.json file only.
 
 CHANGELOG
 
+## v6.2.32 - _August 16, 2021_
+
+    * Dependencies updated
+
+## v6.2.31 - _August 11, 2021_
+
+    * Dependencies updated
+
+## v6.2.30 - _August 6, 2021_
+
+    * Dependencies updated
+
+## v6.2.29 - _June 22, 2021_
+
+    * Dependencies updated
+
+## v6.2.28 - _June 11, 2021_
+
+    * Dependencies updated
+
+## v6.2.27 - _June 2, 2021_
+
+    * Dependencies updated
+
+## v6.2.26 - _May 25, 2021_
+
+    * Dependencies updated
+
+## v6.2.25 - _May 21, 2021_
+
+    * Dependencies updated
+
 ## v6.2.24 - _May 5, 2021_
 
     * Dependencies updated

contracts/extensions/package.json

@@ -1,6 +1,6 @@
 {
     "name": "@0x/contracts-extensions",
-    "version": "6.2.24",
+    "version": "6.2.32",
     "engines": {
         "node": ">=6.12"
     },
@@ -53,16 +53,16 @@
     "homepage": "https://github.com/0xProject/protocol/tree/main/contracts/extensions",
     "devDependencies": {
         "@0x/abi-gen": "^5.6.0",
-        "@0x/contracts-asset-proxy": "^3.7.11",
-        "@0x/contracts-dev-utils": "^1.3.28",
-        "@0x/contracts-erc20": "^3.3.8",
-        "@0x/contracts-erc721": "^3.1.29",
-        "@0x/contracts-exchange": "^3.2.30",
-        "@0x/contracts-exchange-libs": "^4.3.29",
+        "@0x/contracts-asset-proxy": "^3.7.19",
+        "@0x/contracts-dev-utils": "^1.3.36",
+        "@0x/contracts-erc20": "^3.3.16",
+        "@0x/contracts-erc721": "^3.1.37",
+        "@0x/contracts-exchange": "^3.2.38",
+        "@0x/contracts-exchange-libs": "^4.3.37",
         "@0x/contracts-gen": "^2.0.38",
-        "@0x/contracts-utils": "^4.7.8",
+        "@0x/contracts-utils": "^4.7.16",
         "@0x/dev-utils": "^4.2.7",
-        "@0x/order-utils": "^10.4.21",
+        "@0x/order-utils": "^10.4.28",
         "@0x/sol-compiler": "^4.7.3",
         "@0x/ts-doc-gen": "^0.0.28",
         "@0x/tslint-config": "^4.1.4",
@@ -91,7 +91,7 @@
     },
     "dependencies": {
         "@0x/base-contract": "^6.4.0",
-        "@0x/contracts-test-utils": "^5.4.0",
+        "@0x/contracts-test-utils": "^5.4.8",
         "@0x/typescript-typings": "^5.2.0",
         "ethereum-types": "^3.5.0"
     },

contracts/integrations/package.json

@@ -1,6 +1,6 @@
 {
     "name": "@0x/contracts-integrations",
-    "version": "2.7.41",
+    "version": "2.7.64",
     "private": true,
     "engines": {
         "node": ">=6.12"
@@ -53,21 +53,21 @@
     "homepage": "https://github.com/0xProject/protocol/tree/main/contracts/extensions",
     "devDependencies": {
         "@0x/abi-gen": "^5.6.0",
-        "@0x/contract-addresses": "^6.1.0",
-        "@0x/contract-wrappers": "^13.16.1",
-        "@0x/contracts-broker": "^1.1.29",
-        "@0x/contracts-coordinator": "^3.1.30",
-        "@0x/contracts-dev-utils": "^1.3.28",
-        "@0x/contracts-exchange-forwarder": "^4.2.30",
-        "@0x/contracts-exchange-libs": "^4.3.29",
-        "@0x/contracts-extensions": "^6.2.24",
+        "@0x/contract-addresses": "^6.6.0",
+        "@0x/contract-wrappers": "^13.17.4",
+        "@0x/contracts-broker": "^1.1.37",
+        "@0x/contracts-coordinator": "^3.1.38",
+        "@0x/contracts-dev-utils": "^1.3.36",
+        "@0x/contracts-exchange-forwarder": "^4.2.38",
+        "@0x/contracts-exchange-libs": "^4.3.37",
+        "@0x/contracts-extensions": "^6.2.32",
         "@0x/contracts-gen": "^2.0.38",
-        "@0x/contracts-utils": "^4.7.8",
+        "@0x/contracts-utils": "^4.7.16",
         "@0x/coordinator-server": "^1.0.5",
         "@0x/dev-utils": "^4.2.7",
-        "@0x/migrations": "^8.0.6",
-        "@0x/order-utils": "^10.4.21",
-        "@0x/protocol-utils": "^1.6.0",
+        "@0x/migrations": "^8.1.1",
+        "@0x/order-utils": "^10.4.28",
+        "@0x/protocol-utils": "^1.8.2",
         "@0x/sol-compiler": "^4.7.3",
         "@0x/tslint-config": "^4.1.4",
         "@0x/web3-wrapper": "^7.5.3",
@@ -93,17 +93,17 @@
         "typescript": "4.2.2"
     },
     "dependencies": {
-        "@0x/asset-swapper": "^6.11.0",
+        "@0x/asset-swapper": "^16.25.0",
         "@0x/base-contract": "^6.4.0",
-        "@0x/contracts-asset-proxy": "^3.7.11",
-        "@0x/contracts-erc1155": "^2.1.29",
-        "@0x/contracts-erc20": "^3.3.8",
-        "@0x/contracts-erc721": "^3.1.29",
-        "@0x/contracts-exchange": "^3.2.30",
-        "@0x/contracts-multisig": "^4.1.30",
-        "@0x/contracts-staking": "^2.0.37",
-        "@0x/contracts-test-utils": "^5.4.0",
-        "@0x/contracts-zero-ex": "^0.23.0",
+        "@0x/contracts-asset-proxy": "^3.7.19",
+        "@0x/contracts-erc1155": "^2.1.37",
+        "@0x/contracts-erc20": "^3.3.16",
+        "@0x/contracts-erc721": "^3.1.37",
+        "@0x/contracts-exchange": "^3.2.38",
+        "@0x/contracts-multisig": "^4.1.38",
+        "@0x/contracts-staking": "^2.0.45",
+        "@0x/contracts-test-utils": "^5.4.8",
+        "@0x/contracts-zero-ex": "^0.28.0",
         "@0x/subproviders": "^6.5.3",
         "@0x/types": "^3.3.3",
         "@0x/typescript-typings": "^5.2.0",

contracts/integrations/test/coordinator/client_test.ts

@@ -534,9 +534,14 @@ blockchainTests.skip('Coordinator Client', env => {
             const signedOrders = [signedOrder, signedOrderWithDifferentFeeRecipient];
             const takerAssetFillAmounts = [takerTokenFillAmount, takerTokenFillAmount, takerTokenFillAmount];
             await coordinatorClient
-                .batchFillOrdersAsync(signedOrders, takerAssetFillAmounts, signedOrders.map(o => o.signature), {
-                    from: takerAddress,
-                })
+                .batchFillOrdersAsync(
+                    signedOrders,
+                    takerAssetFillAmounts,
+                    signedOrders.map(o => o.signature),
+                    {
+                        from: takerAddress,
+                    },
+                )
                 .then(res => {
                     expect(res).to.be.undefined();
                 })
@@ -570,9 +575,14 @@ blockchainTests.skip('Coordinator Client', env => {
             const signedOrders = [signedOrder, signedOrderWithDifferentCoordinatorOperator];
             const takerAssetFillAmounts = [takerTokenFillAmount, takerTokenFillAmount, takerTokenFillAmount];
             await coordinatorClient
-                .batchFillOrdersAsync(signedOrders, takerAssetFillAmounts, signedOrders.map(o => o.signature), {
-                    from: takerAddress,
-                })
+                .batchFillOrdersAsync(
+                    signedOrders,
+                    takerAssetFillAmounts,
+                    signedOrders.map(o => o.signature),
+                    {
+                        from: takerAddress,
+                    },
+                )
                 .then(res => {
                     expect(res).to.be.undefined();
                 })
@@ -600,9 +610,14 @@ blockchainTests.skip('Coordinator Client', env => {
             const signedOrders = [signedOrder, signedOrderWithDifferentCoordinatorOperator];
             const takerAssetFillAmounts = [takerTokenFillAmount, takerTokenFillAmount, takerTokenFillAmount];
             await coordinatorClient
-                .batchFillOrdersAsync(signedOrders, takerAssetFillAmounts, signedOrders.map(o => o.signature), {
-                    from: takerAddress,
-                })
+                .batchFillOrdersAsync(
+                    signedOrders,
+                    takerAssetFillAmounts,
+                    signedOrders.map(o => o.signature),
+                    {
+                        from: takerAddress,
+                    },
+                )
                 .then(res => {
                     expect(res).to.be.undefined();
                 })

contracts/integrations/test/coordinator/coordinator_test.ts

@@ -267,7 +267,11 @@ blockchainTests.resets('Coordinator integration tests', env => {
                 expectedBalances.simulateFills(orders, taker.address, txReceipt, deployment, value);
                 await balanceStore.updateBalancesAsync();
                 balanceStore.assertEquals(expectedBalances);
-                verifyEvents(txReceipt, orders.map(order => expectedFillEvent(order)), ExchangeEvents.Fill);
+                verifyEvents(
+                    txReceipt,
+                    orders.map(order => expectedFillEvent(order)),
+                    ExchangeEvents.Fill,
+                );
             });
             it(`${fnName} should fill the orders if called by approver (eth fee, no refund)`, async () => {
                 await balanceStore.updateBalancesAsync();
@@ -280,7 +284,11 @@ blockchainTests.resets('Coordinator integration tests', env => {
                 expectedBalances.simulateFills(orders, taker.address, txReceipt, deployment, value);
                 await balanceStore.updateBalancesAsync();
                 balanceStore.assertEquals(expectedBalances);
-                verifyEvents(txReceipt, orders.map(order => expectedFillEvent(order)), ExchangeEvents.Fill);
+                verifyEvents(
+                    txReceipt,
+                    orders.map(order => expectedFillEvent(order)),
+                    ExchangeEvents.Fill,
+                );
             });
             it(`${fnName} should fill the orders if called by approver (mixed fees, refund)`, async () => {
                 await balanceStore.updateBalancesAsync();
@@ -293,7 +301,11 @@ blockchainTests.resets('Coordinator integration tests', env => {
                 expectedBalances.simulateFills(orders, taker.address, txReceipt, deployment, value);
                 await balanceStore.updateBalancesAsync();
                 balanceStore.assertEquals(expectedBalances);
-                verifyEvents(txReceipt, orders.map(order => expectedFillEvent(order)), ExchangeEvents.Fill);
+                verifyEvents(
+                    txReceipt,
+                    orders.map(order => expectedFillEvent(order)),
+                    ExchangeEvents.Fill,
+                );
             });
             it(`${fnName} should revert with an invalid approval signature`, async () => {
                 const approvalSignature = hexUtils.concat(
@@ -360,7 +372,11 @@ blockchainTests.resets('Coordinator integration tests', env => {
                 .executeTransaction(transaction, maker.address, transaction.signature, [])
                 .awaitTransactionSuccessAsync({ from: maker.address });
 
-            verifyEvents(txReceipt, orders.map(order => expectedCancelEvent(order)), ExchangeEvents.Cancel);
+            verifyEvents(
+                txReceipt,
+                orders.map(order => expectedCancelEvent(order)),
+                ExchangeEvents.Cancel,
+            );
         });
         it('cancelOrdersUpTo call should be successful without an approval', async () => {
             const data = exchangeDataEncoder.encodeOrdersToExchangeData(ExchangeFunctionName.CancelOrdersUpTo, []);

contracts/integrations/test/dev-utils/lib_asset_data.ts

@@ -186,13 +186,13 @@ blockchainTests.resets('LibAssetData', env => {
         });
 
         it('should decode multiasset data', async () => {
-            expect(await devUtils.decodeMultiAssetData(KNOWN_MULTI_ASSET_ENCODING.assetData).callAsync()).to.deep.equal(
-                [
-                    AssetProxyId.MultiAsset,
-                    KNOWN_MULTI_ASSET_ENCODING.amounts,
-                    KNOWN_MULTI_ASSET_ENCODING.nestedAssetData,
-                ],
-            );
+            expect(
+                await devUtils.decodeMultiAssetData(KNOWN_MULTI_ASSET_ENCODING.assetData).callAsync(),
+            ).to.deep.equal([
+                AssetProxyId.MultiAsset,
+                KNOWN_MULTI_ASSET_ENCODING.amounts,
+                KNOWN_MULTI_ASSET_ENCODING.nestedAssetData,
+            ]);
         });
 
         it('should encode StaticCall data', async () => {

contracts/integrations/test/exchange/batch_match_orders_test.ts

@@ -278,15 +278,21 @@ blockchainTests.resets('matchOrders integration tests', env => {
                 ExchangeRevertErrors.BatchMatchOrdersErrorCodes.InvalidLengthRightSignatures,
             );
             let tx = deployment.exchange
-                .batchMatchOrders(leftOrders, rightOrders, leftOrders.map(order => order.signature), [
-                    rightOrders[0].signature,
-                ])
+                .batchMatchOrders(
+                    leftOrders,
+                    rightOrders,
+                    leftOrders.map(order => order.signature),
+                    [rightOrders[0].signature],
+                )
                 .awaitTransactionSuccessAsync({ from: matcher.address });
             await expect(tx).to.revertWith(expectedError);
             tx = deployment.exchange
-                .batchMatchOrdersWithMaximalFill(leftOrders, rightOrders, leftOrders.map(order => order.signature), [
-                    rightOrders[0].signature,
-                ])
+                .batchMatchOrdersWithMaximalFill(
+                    leftOrders,
+                    rightOrders,
+                    leftOrders.map(order => order.signature),
+                    [rightOrders[0].signature],
+                )
                 .awaitTransactionSuccessAsync({ from: matcher.address });
             return expect(tx).to.revertWith(expectedError);
         });
@@ -475,7 +481,10 @@ blockchainTests.resets('matchOrders integration tests', env => {
                 ],
                 leftOrdersTakerAssetFilledAmounts: [constants.ZERO_AMOUNT, constants.ZERO_AMOUNT],
                 rightOrdersTakerAssetFilledAmounts: [constants.ZERO_AMOUNT],
-                matchIndices: [[0, 0], [1, 0]],
+                matchIndices: [
+                    [0, 0],
+                    [1, 0],
+                ],
                 shouldMaximallyFill: false,
             });
         });
@@ -524,7 +533,10 @@ blockchainTests.resets('matchOrders integration tests', env => {
                 ],
                 leftOrdersTakerAssetFilledAmounts: [constants.ZERO_AMOUNT],
                 rightOrdersTakerAssetFilledAmounts: [constants.ZERO_AMOUNT, constants.ZERO_AMOUNT],
-                matchIndices: [[0, 0], [0, 1]],
+                matchIndices: [
+                    [0, 0],
+                    [0, 1],
+                ],
                 shouldMaximallyFill: false,
             });
         });
@@ -626,7 +638,11 @@ blockchainTests.resets('matchOrders integration tests', env => {
                 ],
                 leftOrdersTakerAssetFilledAmounts: [constants.ZERO_AMOUNT, constants.ZERO_AMOUNT],
                 rightOrdersTakerAssetFilledAmounts: [constants.ZERO_AMOUNT, constants.ZERO_AMOUNT],
-                matchIndices: [[0, 0], [0, 1], [1, 1]],
+                matchIndices: [
+                    [0, 0],
+                    [0, 1],
+                    [1, 1],
+                ],
                 shouldMaximallyFill: false,
             });
         });
@@ -801,7 +817,11 @@ blockchainTests.resets('matchOrders integration tests', env => {
                 ],
                 leftOrdersTakerAssetFilledAmounts: [constants.ZERO_AMOUNT, constants.ZERO_AMOUNT],
                 rightOrdersTakerAssetFilledAmounts: [constants.ZERO_AMOUNT, constants.ZERO_AMOUNT],
-                matchIndices: [[0, 0], [1, 0], [1, 1]],
+                matchIndices: [
+                    [0, 0],
+                    [1, 0],
+                    [1, 1],
+                ],
                 shouldMaximallyFill: true,
             });
         });

contracts/integrations/test/forwarder/forwarder_mainnet_test.ts

@@ -106,7 +106,12 @@ blockchainTests.fork.resets('Forwarder mainnet tests', env => {
                 orders[1].takerAssetAmount.dividedToIntegerBy(2),
             );
             const [wethSpentAmount, makerAssetAcquiredAmount] = await forwarder
-                .marketSellOrdersWithEth(orders, orders.map(o => o.signature), [], [])
+                .marketSellOrdersWithEth(
+                    orders,
+                    orders.map(o => o.signature),
+                    [],
+                    [],
+                )
                 .callAsync({
                     from: takerAddress,
                     value: ethSellAmount,
@@ -161,7 +166,13 @@ blockchainTests.fork.resets('Forwarder mainnet tests', env => {
                 orders[1].makerAssetAmount.dividedToIntegerBy(2),
             );
             const [wethSpentAmount, makerAssetAcquiredAmount] = await forwarder
-                .marketBuyOrdersWithEth(orders, makerAssetBuyAmount, orders.map(o => o.signature), [], [])
+                .marketBuyOrdersWithEth(
+                    orders,
+                    makerAssetBuyAmount,
+                    orders.map(o => o.signature),
+                    [],
+                    [],
+                )
                 .callAsync({
                     from: takerAddress,
                     value: ethSellAmount,

contracts/integrations/test/framework/actors/maker.ts

@@ -190,9 +190,14 @@ export function MakerMixin<TBase extends Constructor>(Base: TBase): TBase & Cons
                 rightTakerAssetData,
                 makerFeeAssetData,
                 takerFeeAssetData,
-            ] = [leftMakerToken, leftTakerToken, rightMakerToken, rightTakerToken, makerFeeToken, takerFeeToken].map(
-                token => encodeERC20AssetData(token.address),
-            );
+            ] = [
+                leftMakerToken,
+                leftTakerToken,
+                rightMakerToken,
+                rightTakerToken,
+                makerFeeToken,
+                takerFeeToken,
+            ].map(token => encodeERC20AssetData(token.address));
 
             // Construct and sign the left order
             const leftOrder = await this.signOrderAsync({

contracts/integrations/test/framework/actors/utils.ts

@@ -8,7 +8,10 @@ import { Actor, Constructor } from './base';
  * Useful for BalanceStore.
  */
 export function actorAddressesByName(actors: Actor[]): ObjectMap<string> {
-    return _.zipObject(actors.map(actor => actor.name), actors.map(actor => actor.address));
+    return _.zipObject(
+        actors.map(actor => actor.name),
+        actors.map(actor => actor.address),
+    );
 }
 
 /**

contracts/integrations/test/fuzz_tests/exchange_signature_validation_test.ts

@@ -77,19 +77,24 @@ tests('Exchange signature validation fuzz tests', env => {
     before(async () => {
         chainId = await env.web3Wrapper.getChainIdAsync();
         accounts = await env.getAccountAddressesAsync();
-        privateKeys = _.zipObject(accounts, accounts.map((a, i) => constants.TESTRPC_PRIVATE_KEYS[i]));
+        privateKeys = _.zipObject(
+            accounts,
+            accounts.map((a, i) => constants.TESTRPC_PRIVATE_KEYS[i]),
+        );
         deployment = await DeploymentManager.deployAsync(env, {
             numErc20TokensToDeploy: 0,
             numErc721TokensToDeploy: 0,
             numErc1155TokensToDeploy: 0,
         });
         exchange = deployment.exchange;
-        walletContractAddress = (await TestSignatureValidationWalletContract.deployFrom0xArtifactAsync(
-            artifacts.TestSignatureValidationWallet,
-            env.provider,
-            env.txDefaults,
-            {},
-        )).address;
+        walletContractAddress = (
+            await TestSignatureValidationWalletContract.deployFrom0xArtifactAsync(
+                artifacts.TestSignatureValidationWallet,
+                env.provider,
+                env.txDefaults,
+                {},
+            )
+        ).address;
         // This just has to be a contract address that doesn't implement the
         // wallet spec.
         notWalletContractAddress = exchange.address;
@@ -715,7 +720,7 @@ tests('Exchange signature validation fuzz tests', env => {
             invalidTestTransactionMangledSignature(),
         ];
         const simulationEnvironment = new SimulationEnvironment(deployment, new BlockchainBalanceStore({}, {}), []);
-        const simulation = new class extends Simulation {
+        const simulation = new (class extends Simulation {
             // tslint:disable-next-line: prefer-function-over-method
             protected async *_assertionGenerator(): AsyncIterableIterator<AssertionResult | void> {
                 while (true) {
@@ -723,7 +728,7 @@ tests('Exchange signature validation fuzz tests', env => {
                     yield (await action!.next()).value;
                 }
             }
-        }(simulationEnvironment);
+        })(simulationEnvironment);
         simulation.resets = true;
         return simulation.fuzzAsync();
     });

contracts/multisig/CHANGELOG.json

@@ -1,4 +1,76 @@
 [
+    {
+        "timestamp": 1629079369,
+        "version": "4.1.38",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1628665757,
+        "version": "4.1.37",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1628225642,
+        "version": "4.1.36",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1624356181,
+        "version": "4.1.35",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1623382456,
+        "version": "4.1.34",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1622609597,
+        "version": "4.1.33",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1621944788,
+        "version": "4.1.32",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1621600614,
+        "version": "4.1.31",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
     {
         "timestamp": 1620214333,
         "version": "4.1.30",

contracts/multisig/CHANGELOG.md

@@ -5,6 +5,38 @@ Edit the package's CHANGELOG.json file only.
 
 CHANGELOG
 
+## v4.1.38 - _August 16, 2021_
+
+    * Dependencies updated
+
+## v4.1.37 - _August 11, 2021_
+
+    * Dependencies updated
+
+## v4.1.36 - _August 6, 2021_
+
+    * Dependencies updated
+
+## v4.1.35 - _June 22, 2021_
+
+    * Dependencies updated
+
+## v4.1.34 - _June 11, 2021_
+
+    * Dependencies updated
+
+## v4.1.33 - _June 2, 2021_
+
+    * Dependencies updated
+
+## v4.1.32 - _May 25, 2021_
+
+    * Dependencies updated
+
+## v4.1.31 - _May 21, 2021_
+
+    * Dependencies updated
+
 ## v4.1.30 - _May 5, 2021_
 
     * Dependencies updated

contracts/multisig/package.json

@@ -1,6 +1,6 @@
 {
     "name": "@0x/contracts-multisig",
-    "version": "4.1.30",
+    "version": "4.1.38",
     "engines": {
         "node": ">=6.12"
     },
@@ -50,11 +50,11 @@
     "homepage": "https://github.com/0xProject/protocol/tree/main/contracts/multisig",
     "devDependencies": {
         "@0x/abi-gen": "^5.6.0",
-        "@0x/contracts-asset-proxy": "^3.7.11",
-        "@0x/contracts-erc20": "^3.3.8",
+        "@0x/contracts-asset-proxy": "^3.7.19",
+        "@0x/contracts-erc20": "^3.3.16",
         "@0x/contracts-gen": "^2.0.38",
-        "@0x/contracts-test-utils": "^5.4.0",
-        "@0x/contracts-utils": "^4.7.8",
+        "@0x/contracts-test-utils": "^5.4.8",
+        "@0x/contracts-utils": "^4.7.16",
         "@0x/dev-utils": "^4.2.7",
         "@0x/sol-compiler": "^4.7.3",
         "@0x/tslint-config": "^4.1.4",

contracts/staking/CHANGELOG.json

@@ -1,4 +1,76 @@
 [
+    {
+        "timestamp": 1629079369,
+        "version": "2.0.45",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1628665757,
+        "version": "2.0.44",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1628225642,
+        "version": "2.0.43",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1624356181,
+        "version": "2.0.42",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1623382456,
+        "version": "2.0.41",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1622609597,
+        "version": "2.0.40",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1621944788,
+        "version": "2.0.39",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1621600614,
+        "version": "2.0.38",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
     {
         "version": "2.0.37",
         "changes": [

contracts/staking/CHANGELOG.md

@@ -5,6 +5,38 @@ Edit the package's CHANGELOG.json file only.
 
 CHANGELOG
 
+## v2.0.45 - _August 16, 2021_
+
+    * Dependencies updated
+
+## v2.0.44 - _August 11, 2021_
+
+    * Dependencies updated
+
+## v2.0.43 - _August 6, 2021_
+
+    * Dependencies updated
+
+## v2.0.42 - _June 22, 2021_
+
+    * Dependencies updated
+
+## v2.0.41 - _June 11, 2021_
+
+    * Dependencies updated
+
+## v2.0.40 - _June 2, 2021_
+
+    * Dependencies updated
+
+## v2.0.39 - _May 25, 2021_
+
+    * Dependencies updated
+
+## v2.0.38 - _May 21, 2021_
+
+    * Dependencies updated
+
 ## v2.0.37 - _May 5, 2021_
 
     * Patch epoch finalization issue (#221)

contracts/staking/package.json

@@ -1,6 +1,6 @@
 {
     "name": "@0x/contracts-staking",
-    "version": "2.0.37",
+    "version": "2.0.45",
     "engines": {
         "node": ">=6.12"
     },
@@ -54,14 +54,14 @@
     "homepage": "https://github.com/0xProject/protocol/tree/main/contracts/tokens",
     "devDependencies": {
         "@0x/abi-gen": "^5.6.0",
-        "@0x/contracts-asset-proxy": "^3.7.11",
-        "@0x/contracts-dev-utils": "^1.3.28",
-        "@0x/contracts-erc20": "^3.3.8",
-        "@0x/contracts-exchange-libs": "^4.3.29",
+        "@0x/contracts-asset-proxy": "^3.7.19",
+        "@0x/contracts-dev-utils": "^1.3.36",
+        "@0x/contracts-erc20": "^3.3.16",
+        "@0x/contracts-exchange-libs": "^4.3.37",
         "@0x/contracts-gen": "^2.0.38",
-        "@0x/contracts-utils": "^4.7.8",
+        "@0x/contracts-utils": "^4.7.16",
         "@0x/dev-utils": "^4.2.7",
-        "@0x/order-utils": "^10.4.21",
+        "@0x/order-utils": "^10.4.28",
         "@0x/sol-compiler": "^4.7.3",
         "@0x/ts-doc-gen": "^0.0.28",
         "@0x/tslint-config": "^4.1.4",
@@ -88,7 +88,7 @@
     },
     "dependencies": {
         "@0x/base-contract": "^6.4.0",
-        "@0x/contracts-test-utils": "^5.4.0",
+        "@0x/contracts-test-utils": "^5.4.8",
         "@0x/typescript-typings": "^5.2.0",
         "@0x/utils": "^6.4.3",
         "ethereum-types": "^3.5.0",

contracts/staking/test/actors/finalizer_actor.ts

@@ -157,11 +157,11 @@ export class FinalizerActor extends BaseActor {
             const delegators = delegatorsByPoolId[poolId];
             delegatorBalancesByPoolId[poolId] = {};
             for (const delegator of delegators) {
-                delegatorBalancesByPoolId[poolId][
-                    delegator
-                ] = (await this._stakingApiWrapper.stakingContract
-                    .getStakeDelegatedToPoolByOwner(delegator, poolId)
-                    .callAsync()).currentEpochBalance;
+                delegatorBalancesByPoolId[poolId][delegator] = (
+                    await this._stakingApiWrapper.stakingContract
+                        .getStakeDelegatedToPoolByOwner(delegator, poolId)
+                        .callAsync()
+                ).currentEpochBalance;
             }
         }
         return delegatorBalancesByPoolId;
@@ -253,7 +253,10 @@ export class FinalizerActor extends BaseActor {
         const totalFeesCollected = BigNumber.sum(...activePools.map(p => p.feesCollected));
         const totalWeightedStake = BigNumber.sum(...activePools.map(p => p.weightedStake));
         if (totalRewards.eq(0) || totalFeesCollected.eq(0) || totalWeightedStake.eq(0)) {
-            return _.zipObject(poolIds, _.times(poolIds.length, () => new BigNumber(0)));
+            return _.zipObject(
+                poolIds,
+                _.times(poolIds.length, () => new BigNumber(0)),
+            );
         }
         const rewards = await Promise.all(
             activePools.map(async pool =>

contracts/staking/test/migration_test.ts

@@ -102,13 +102,15 @@ blockchainTests('Migration tests', env => {
             });
 
             it('should set the correct initial params', async () => {
-                const stakingProxyContractAddress = (await StakingProxyContract.deployFrom0xArtifactAsync(
-                    artifacts.StakingProxy,
-                    env.provider,
-                    env.txDefaults,
-                    artifacts,
-                    stakingContract.address,
-                )).address;
+                const stakingProxyContractAddress = (
+                    await StakingProxyContract.deployFrom0xArtifactAsync(
+                        artifacts.StakingProxy,
+                        env.provider,
+                        env.txDefaults,
+                        artifacts,
+                        stakingContract.address,
+                    )
+                ).address;
 
                 const stakingProxyContract = new StakingContract(
                     stakingProxyContractAddress,

contracts/test-utils/CHANGELOG.json

@@ -1,4 +1,76 @@
 [
+    {
+        "timestamp": 1629079369,
+        "version": "5.4.8",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1628665757,
+        "version": "5.4.7",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1628225642,
+        "version": "5.4.6",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1624356181,
+        "version": "5.4.5",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1623382456,
+        "version": "5.4.4",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1622609597,
+        "version": "5.4.3",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1621944788,
+        "version": "5.4.2",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1621600614,
+        "version": "5.4.1",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
     {
         "version": "5.4.0",
         "changes": [

contracts/test-utils/CHANGELOG.md

@@ -5,6 +5,38 @@ Edit the package's CHANGELOG.json file only.
 
 CHANGELOG
 
+## v5.4.8 - _August 16, 2021_
+
+    * Dependencies updated
+
+## v5.4.7 - _August 11, 2021_
+
+    * Dependencies updated
+
+## v5.4.6 - _August 6, 2021_
+
+    * Dependencies updated
+
+## v5.4.5 - _June 22, 2021_
+
+    * Dependencies updated
+
+## v5.4.4 - _June 11, 2021_
+
+    * Dependencies updated
+
+## v5.4.3 - _June 2, 2021_
+
+    * Dependencies updated
+
+## v5.4.2 - _May 25, 2021_
+
+    * Dependencies updated
+
+## v5.4.1 - _May 21, 2021_
+
+    * Dependencies updated
+
 ## v5.4.0 - _May 5, 2021_
 
     * Set default ganache gas limit to 100e6 (#197)

contracts/test-utils/package.json

@@ -1,6 +1,6 @@
 {
     "name": "@0x/contracts-test-utils",
-    "version": "5.4.0",
+    "version": "5.4.8",
     "engines": {
         "node": ">=6.12"
     },
@@ -44,10 +44,10 @@
     "dependencies": {
         "@0x/assert": "^3.0.27",
         "@0x/base-contract": "^6.4.0",
-        "@0x/contract-addresses": "^6.1.0",
+        "@0x/contract-addresses": "^6.6.0",
         "@0x/dev-utils": "^4.2.7",
         "@0x/json-schemas": "^6.1.3",
-        "@0x/order-utils": "^10.4.21",
+        "@0x/order-utils": "^10.4.28",
         "@0x/sol-coverage": "^4.0.37",
         "@0x/sol-profiler": "^4.1.27",
         "@0x/sol-trace": "^3.0.37",

contracts/test-utils/src/log_utils.ts

@@ -40,6 +40,6 @@ export function verifyEventsFromLogs<TEventArgs>(
     const _logs = filterLogsToArguments<TEventArgs>(logs, eventName);
     expect(_logs.length, `Number of ${eventName} events emitted`).to.eq(expectedEvents.length);
     _logs.forEach((log, index) => {
-        expect(log, `${eventName} event ${index}`).to.deep.equal(expectedEvents[index]);
+        expect(log, `${eventName} event ${index}`).to.deep.equal({ ...log, ...expectedEvents[index] });
     });
 }

contracts/test-utils/src/test_with_reference.ts

@@ -108,9 +108,7 @@ export async function testWithReferenceFuncAsync(
                     return expect.fail(
                         actualError,
                         expectedError,
-                        `${testCaseString}: expected error message '${actualError.message}' to equal '${
-                            expectedError.message
-                        }'`,
+                        `${testCaseString}: expected error message '${actualError.message}' to equal '${expectedError.message}'`,
                     );
                 }
             }

contracts/treasury/CHANGELOG.json

@@ -1,4 +1,87 @@
 [
+    {
+        "timestamp": 1629079369,
+        "version": "1.3.2",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1628665757,
+        "version": "1.3.1",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "version": "1.3.0",
+        "changes": [
+            {
+                "note": "Added proposal 1 params and test",
+                "pr": 298
+            }
+        ],
+        "timestamp": 1628225642
+    },
+    {
+        "timestamp": 1624356181,
+        "version": "1.2.3",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1623382456,
+        "version": "1.2.2",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1622609597,
+        "version": "1.2.1",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "version": "1.2.0",
+        "changes": [
+            {
+                "note": "Added proposal 0 params and test",
+                "pr": 252
+            }
+        ],
+        "timestamp": 1622154125
+    },
+    {
+        "timestamp": 1621944788,
+        "version": "1.1.8",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1621600614,
+        "version": "1.1.7",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
     {
         "timestamp": 1620214333,
         "version": "1.1.6",

contracts/treasury/CHANGELOG.md

@@ -5,6 +5,42 @@ Edit the package's CHANGELOG.json file only.
 
 CHANGELOG
 
+## v1.3.2 - _August 16, 2021_
+
+    * Dependencies updated
+
+## v1.3.1 - _August 11, 2021_
+
+    * Dependencies updated
+
+## v1.3.0 - _August 6, 2021_
+
+    * Added proposal 1 params and test (#298)
+
+## v1.2.3 - _June 22, 2021_
+
+    * Dependencies updated
+
+## v1.2.2 - _June 11, 2021_
+
+    * Dependencies updated
+
+## v1.2.1 - _June 2, 2021_
+
+    * Dependencies updated
+
+## v1.2.0 - _May 27, 2021_
+
+    * Added proposal 0 params and test (#252)
+
+## v1.1.8 - _May 25, 2021_
+
+    * Dependencies updated
+
+## v1.1.7 - _May 21, 2021_
+
+    * Dependencies updated
+
 ## v1.1.6 - _May 5, 2021_
 
     * Dependencies updated

contracts/treasury/contracts/src/DefaultPoolOperator.sol

@@ -21,13 +21,10 @@ pragma solidity ^0.6.12;
 pragma experimental ABIEncoderV2;
 
 import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
-import "@0x/contracts-erc20/contracts/src/v06/LibERC20TokenV06.sol";
 import "./IStaking.sol";
 
 
 contract DefaultPoolOperator {
-    using LibERC20TokenV06 for IERC20TokenV06;
-
     // Immutables
     IStaking public immutable stakingProxy;
     IERC20TokenV06 public immutable weth;
@@ -57,7 +54,7 @@ contract DefaultPoolOperator {
     function returnStakingRewards()
         external
     {
-        uint256 wethBalance = weth.compatBalanceOf(address(this));
-        weth.compatTransfer(address(stakingProxy), wethBalance);
+        uint256 wethBalance = weth.balanceOf(address(this));
+        weth.transfer(address(stakingProxy), wethBalance);
     }
 }

contracts/treasury/package.json

@@ -1,6 +1,6 @@
 {
     "name": "@0x/contracts-treasury",
-    "version": "1.1.6",
+    "version": "1.3.2",
     "engines": {
         "node": ">=6.12"
     },
@@ -47,12 +47,12 @@
     "homepage": "https://github.com/0xProject/protocol/tree/main/contracts/treasury",
     "devDependencies": {
         "@0x/abi-gen": "^5.6.0",
-        "@0x/contract-addresses": "^6.1.0",
-        "@0x/contracts-asset-proxy": "^3.7.11",
-        "@0x/contracts-erc20": "^3.3.8",
+        "@0x/contract-addresses": "^6.6.0",
+        "@0x/contracts-asset-proxy": "^3.7.19",
+        "@0x/contracts-erc20": "^3.3.16",
         "@0x/contracts-gen": "^2.0.38",
-        "@0x/contracts-staking": "^2.0.37",
-        "@0x/contracts-test-utils": "^5.4.0",
+        "@0x/contracts-staking": "^2.0.45",
+        "@0x/contracts-test-utils": "^5.4.8",
         "@0x/sol-compiler": "^4.7.3",
         "@0x/ts-doc-gen": "^0.0.28",
         "@0x/tslint-config": "^4.1.4",
@@ -73,7 +73,7 @@
     },
     "dependencies": {
         "@0x/base-contract": "^6.4.0",
-        "@0x/protocol-utils": "^1.6.0",
+        "@0x/protocol-utils": "^1.8.2",
         "@0x/subproviders": "^6.5.3",
         "@0x/types": "^3.3.3",
         "@0x/typescript-typings": "^5.2.0",

contracts/treasury/test/proposal_test.ts

@@ -0,0 +1,222 @@
+import { artifacts as erc20Artifacts, ERC20TokenEvents } from '@0x/contracts-erc20';
+import { StakingContract, StakingProxyContract } from '@0x/contracts-staking';
+import { blockchainTests, constants, verifyEventsFromLogs } from '@0x/contracts-test-utils';
+import { BigNumber, hexUtils, logUtils } from '@0x/utils';
+import * as _ from 'lodash';
+
+import { proposals } from '../src/proposals';
+
+import { artifacts } from './artifacts';
+import { ZrxTreasuryContract, ZrxTreasuryEvents } from './wrappers';
+
+const SUBGRAPH_URL = 'https://api.thegraph.com/subgraphs/name/mzhu25/zeroex-staking';
+const STAKING_PROXY_ADDRESS = '0xa26e80e7dea86279c6d778d702cc413e6cffa777';
+const TREASURY_ADDRESS = '0x0bb1810061c2f5b2088054ee184e6c79e1591101';
+const PROPOSER = process.env.PROPOSER || constants.NULL_ADDRESS;
+const VOTER = '0xba4f44e774158408e2dc6c5cb65bc995f0a89180';
+const VOTER_OPERATED_POOLS = ['0x0000000000000000000000000000000000000000000000000000000000000017'];
+blockchainTests.configure({
+    fork: {
+        unlockedAccounts: [PROPOSER, VOTER],
+    },
+});
+
+async function querySubgraphAsync(operatorAddress: string): Promise<string[]> {
+    const query = `
+        {
+            stakingActor(id: "${operatorAddress}") {
+                operatedPools {
+                    id
+                }
+            }
+        }
+    `;
+    const response = await fetch(SUBGRAPH_URL, {
+        method: 'POST',
+        headers: {
+            Accept: 'application/json',
+            'Content-Type': 'application/json',
+        },
+        body: JSON.stringify({
+            query,
+        }),
+    });
+    const {
+        data: { stakingActor },
+    } = await response.json();
+    if (stakingActor) {
+        return stakingActor.operatedPools.map((pool: { id: string }) => hexUtils.leftPad(pool.id));
+    } else {
+        return [];
+    }
+}
+
+blockchainTests.fork.skip('Treasury proposal mainnet fork tests', env => {
+    let staking: StakingContract;
+    let stakingProxy: StakingProxyContract;
+    let treasury: ZrxTreasuryContract;
+    let votingPeriod: BigNumber;
+
+    async function fastForwardToNextEpochAsync(): Promise<void> {
+        const epochEndTime = await staking.getCurrentEpochEarliestEndTimeInSeconds().callAsync();
+        const lastBlockTime = await env.web3Wrapper.getBlockTimestampAsync('latest');
+        const dt = Math.max(0, epochEndTime.minus(lastBlockTime).toNumber());
+        await env.web3Wrapper.increaseTimeAsync(dt);
+        // mine next block
+        await env.web3Wrapper.mineBlockAsync();
+        const lastPoolId = new BigNumber(await staking.lastPoolId().callAsync(), 16);
+        const batchExecuteCalldata = [
+            ...[...new Array(lastPoolId.toNumber())].map((_x, i) =>
+                staking.finalizePool(hexUtils.leftPad(i + 1)).getABIEncodedTransactionData(),
+            ),
+            staking.endEpoch().getABIEncodedTransactionData(),
+            ...[...new Array(lastPoolId.toNumber())].map((_x, i) =>
+                staking.finalizePool(hexUtils.leftPad(i + 1)).getABIEncodedTransactionData(),
+            ),
+            ...[...new Array(lastPoolId.toNumber())].map((_x, i) =>
+                staking.finalizePool(hexUtils.leftPad(i + 1)).getABIEncodedTransactionData(),
+            ),
+        ];
+        await stakingProxy.batchExecute(batchExecuteCalldata).awaitTransactionSuccessAsync();
+    }
+
+    before(async () => {
+        const abis = _.mapValues({ ...artifacts, ...erc20Artifacts }, v => v.compilerOutput.abi);
+        treasury = new ZrxTreasuryContract(TREASURY_ADDRESS, env.provider, env.txDefaults, abis);
+        votingPeriod = await treasury.votingPeriod().callAsync();
+        staking = new StakingContract(STAKING_PROXY_ADDRESS, env.provider, env.txDefaults);
+        stakingProxy = new StakingProxyContract(STAKING_PROXY_ADDRESS, env.provider, env.txDefaults);
+    });
+
+    describe('Proposal 0', () => {
+        it('works', async () => {
+            const proposal = proposals[0];
+            let executionEpoch: BigNumber;
+            if (proposal.executionEpoch) {
+                executionEpoch = proposal.executionEpoch;
+            } else {
+                const currentEpoch = await staking.currentEpoch().callAsync();
+                executionEpoch = currentEpoch.plus(2);
+            }
+            const pools = await querySubgraphAsync(PROPOSER);
+            const proposeTx = treasury.propose(proposal.actions, executionEpoch, proposal.description, pools);
+
+            const calldata = proposeTx.getABIEncodedTransactionData();
+            logUtils.log('ZrxTreasury.propose calldata:');
+            logUtils.log(calldata);
+
+            const proposalId = await proposeTx.callAsync({ from: PROPOSER });
+            const receipt = await proposeTx.awaitTransactionSuccessAsync({ from: PROPOSER });
+            verifyEventsFromLogs(
+                receipt.logs,
+                [
+                    {
+                        ...proposal,
+                        proposalId,
+                        executionEpoch,
+                        proposer: PROPOSER,
+                        operatedPoolIds: pools,
+                    },
+                ],
+                ZrxTreasuryEvents.ProposalCreated,
+            );
+            await fastForwardToNextEpochAsync();
+            await fastForwardToNextEpochAsync();
+            await treasury
+                .castVote(proposalId, true, VOTER_OPERATED_POOLS)
+                .awaitTransactionSuccessAsync({ from: VOTER });
+            await env.web3Wrapper.increaseTimeAsync(votingPeriod.plus(1).toNumber());
+            await env.web3Wrapper.mineBlockAsync();
+            const executeTx = await treasury.execute(proposalId, proposal.actions).awaitTransactionSuccessAsync();
+            verifyEventsFromLogs(
+                executeTx.logs,
+                [
+                    {
+                        proposalId,
+                    },
+                ],
+                ZrxTreasuryEvents.ProposalExecuted,
+            );
+            const recipient = '0xf9347f751a6a1467abc722ec7d80ba2698dd9d6c';
+            verifyEventsFromLogs(
+                executeTx.logs,
+                [
+                    {
+                        _from: TREASURY_ADDRESS,
+                        _to: recipient,
+                        _value: new BigNumber(400_000).times('1e18'),
+                    },
+                ],
+                ERC20TokenEvents.Transfer,
+            );
+        });
+    });
+    describe('Proposal 1', () => {
+        it('works', async () => {
+            const proposal = proposals[1];
+            let executionEpoch: BigNumber;
+            if (proposal.executionEpoch) {
+                executionEpoch = proposal.executionEpoch;
+            } else {
+                const currentEpoch = await staking.currentEpoch().callAsync();
+                executionEpoch = currentEpoch.plus(2);
+            }
+            const pools = await querySubgraphAsync(PROPOSER);
+            const proposeTx = treasury.propose(proposal.actions, executionEpoch, proposal.description, pools);
+
+            const calldata = proposeTx.getABIEncodedTransactionData();
+            logUtils.log('ZrxTreasury.propose calldata:');
+            logUtils.log(calldata);
+
+            const proposalId = await proposeTx.callAsync({ from: PROPOSER });
+            const receipt = await proposeTx.awaitTransactionSuccessAsync({ from: PROPOSER });
+            verifyEventsFromLogs(
+                receipt.logs,
+                [
+                    {
+                        ...proposal,
+                        proposalId,
+                        executionEpoch,
+                        proposer: PROPOSER,
+                        operatedPoolIds: pools,
+                    },
+                ],
+                ZrxTreasuryEvents.ProposalCreated,
+            );
+            await fastForwardToNextEpochAsync();
+            await fastForwardToNextEpochAsync();
+            await treasury
+                .castVote(proposalId, true, VOTER_OPERATED_POOLS)
+                .awaitTransactionSuccessAsync({ from: VOTER });
+            await env.web3Wrapper.increaseTimeAsync(votingPeriod.plus(1).toNumber());
+            await env.web3Wrapper.mineBlockAsync();
+            const executeTx = await treasury.execute(proposalId, proposal.actions).awaitTransactionSuccessAsync();
+            verifyEventsFromLogs(
+                executeTx.logs,
+                [
+                    {
+                        proposalId,
+                    },
+                ],
+                ZrxTreasuryEvents.ProposalExecuted,
+            );
+            const recipient = '0xab66cc8fd10457ebc9d13b9760c835f0a4cbc487';
+            verifyEventsFromLogs(
+                executeTx.logs,
+                [
+                    {
+                        _from: TREASURY_ADDRESS,
+                        _to: recipient,
+                        _value: new BigNumber(330_813).times('1e18'),
+                    },
+                    {
+                        _from: TREASURY_ADDRESS,
+                        _to: recipient,
+                        _value: new BigNumber(420000).times('1e18'),
+                    },
+                ],
+                ERC20TokenEvents.Transfer,
+            );
+        });
+    });
+});

contracts/utils/CHANGELOG.json

@@ -1,4 +1,76 @@
 [
+    {
+        "timestamp": 1629079369,
+        "version": "4.7.16",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1628665757,
+        "version": "4.7.15",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1628225642,
+        "version": "4.7.14",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1624356181,
+        "version": "4.7.13",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1623382456,
+        "version": "4.7.12",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1622609597,
+        "version": "4.7.11",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1621944788,
+        "version": "4.7.10",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1621600614,
+        "version": "4.7.9",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
     {
         "timestamp": 1620214333,
         "version": "4.7.8",

contracts/utils/CHANGELOG.md

@@ -5,6 +5,38 @@ Edit the package's CHANGELOG.json file only.
 
 CHANGELOG
 
+## v4.7.16 - _August 16, 2021_
+
+    * Dependencies updated
+
+## v4.7.15 - _August 11, 2021_
+
+    * Dependencies updated
+
+## v4.7.14 - _August 6, 2021_
+
+    * Dependencies updated
+
+## v4.7.13 - _June 22, 2021_
+
+    * Dependencies updated
+
+## v4.7.12 - _June 11, 2021_
+
+    * Dependencies updated
+
+## v4.7.11 - _June 2, 2021_
+
+    * Dependencies updated
+
+## v4.7.10 - _May 25, 2021_
+
+    * Dependencies updated
+
+## v4.7.9 - _May 21, 2021_
+
+    * Dependencies updated
+
 ## v4.7.8 - _May 5, 2021_
 
     * Dependencies updated

contracts/utils/package.json

@@ -1,6 +1,6 @@
 {
     "name": "@0x/contracts-utils",
-    "version": "4.7.8",
+    "version": "4.7.16",
     "engines": {
         "node": ">=6.12"
     },
@@ -52,9 +52,9 @@
     "devDependencies": {
         "@0x/abi-gen": "^5.6.0",
         "@0x/contracts-gen": "^2.0.38",
-        "@0x/contracts-test-utils": "^5.4.0",
+        "@0x/contracts-test-utils": "^5.4.8",
         "@0x/dev-utils": "^4.2.7",
-        "@0x/order-utils": "^10.4.21",
+        "@0x/order-utils": "^10.4.28",
         "@0x/sol-compiler": "^4.7.3",
         "@0x/tslint-config": "^4.1.4",
         "@0x/types": "^3.3.3",

contracts/utils/test/lib_bytes.ts

@@ -536,7 +536,11 @@ blockchainTests('LibBytes', env => {
             ]));
 
         describe('copies forward within one word and one byte overlap', () =>
-            test([[0, 0, 1, 'one byte'], [10, 0, 11, 'eleven bytes'], [15, 0, 16, 'sixteen bytes']]));
+            test([
+                [0, 0, 1, 'one byte'],
+                [10, 0, 11, 'eleven bytes'],
+                [15, 0, 16, 'sixteen bytes'],
+            ]));
 
         describe('copies backward', () =>
             test([
@@ -603,7 +607,11 @@ blockchainTests('LibBytes', env => {
             ]));
 
         describe('copies forward within one word and one byte overlap', () =>
-            test([[0, 0, 1, 'one byte'], [0, 10, 11, 'eleven bytes'], [0, 15, 16, 'sixteen bytes']]));
+            test([
+                [0, 0, 1, 'one byte'],
+                [0, 10, 11, 'eleven bytes'],
+                [0, 15, 16, 'sixteen bytes'],
+            ]));
     });
 
     describe('slice', () => {

contracts/zero-ex/CHANGELOG.json

@@ -1,4 +1,96 @@
 [
+    {
+        "version": "0.28.0",
+        "changes": [
+            {
+                "note": "Transfer output tokens in TransformERC20Feature",
+                "pr": 279
+            },
+            {
+                "note": "Add support for takerToken=0xeee... in OtcOrdersFeature",
+                "pr": 287
+            },
+            {
+                "note": "Add support for OTC orders in MultiplexFeature",
+                "pr": 287
+            },
+            {
+                "note": "Multiplex v2: Refactor into multiple files, add ETH support, and other miscellanea",
+                "pr": 263
+            }
+        ],
+        "timestamp": 1629079369
+    },
+    {
+        "timestamp": 1628665757,
+        "version": "0.27.1",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "version": "0.27.0",
+        "changes": [
+            {
+                "note": "Add `Clipper` as a custom liquidity source"
+            }
+        ],
+        "timestamp": 1628225642
+    },
+    {
+        "version": "0.26.0",
+        "changes": [
+            {
+                "note": "Add Lido stETH deposit integration",
+                "pr": 260
+            }
+        ],
+        "timestamp": 1624356181
+    },
+    {
+        "timestamp": 1623382456,
+        "version": "0.25.1",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "version": "0.25.0",
+        "changes": [
+            {
+                "note": "Add OtcOrdersFeature",
+                "pr": 244
+            },
+            {
+                "note": "Add UniswapV3 VIP feature",
+                "pr": 237
+            }
+        ],
+        "timestamp": 1622609597
+    },
+    {
+        "timestamp": 1621944788,
+        "version": "0.24.1",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "version": "0.24.0",
+        "changes": [
+            {
+                "note": "Add special selectors to selector collision test",
+                "pr": 243
+            }
+        ],
+        "timestamp": 1621600614
+    },
     {
         "version": "0.23.0",
         "changes": [

contracts/zero-ex/CHANGELOG.md

@@ -5,6 +5,42 @@ Edit the package's CHANGELOG.json file only.
 
 CHANGELOG
 
+## v0.28.0 - _August 16, 2021_
+
+    * Transfer output tokens in TransformERC20Feature (#279)
+    * Add support for takerToken=0xeee... in OtcOrdersFeature (#287)
+    * Add support for OTC orders in MultiplexFeature (#287)
+    * Multiplex v2: Refactor into multiple files, add ETH support, and other miscellanea (#263)
+
+## v0.27.1 - _August 11, 2021_
+
+    * Dependencies updated
+
+## v0.27.0 - _August 6, 2021_
+
+    * Add `Clipper` as a custom liquidity source
+
+## v0.26.0 - _June 22, 2021_
+
+    * Add Lido stETH deposit integration (#260)
+
+## v0.25.1 - _June 11, 2021_
+
+    * Dependencies updated
+
+## v0.25.0 - _June 2, 2021_
+
+    * Add OtcOrdersFeature (#244)
+    * Add UniswapV3 VIP feature (#237)
+
+## v0.24.1 - _May 25, 2021_
+
+    * Dependencies updated
+
+## v0.24.0 - _May 21, 2021_
+
+    * Add special selectors to selector collision test (#243)
+
 ## v0.23.0 - _May 5, 2021_
 
     * Added ETH support to `MixinCurve` (#220)

contracts/zero-ex/contracts/src/IZeroEx.sol

@@ -26,11 +26,13 @@ import "./features/interfaces/ITokenSpenderFeature.sol";
 import "./features/interfaces/ITransformERC20Feature.sol";
 import "./features/interfaces/IMetaTransactionsFeature.sol";
 import "./features/interfaces/IUniswapFeature.sol";
+import "./features/interfaces/IUniswapV3Feature.sol";
 import "./features/interfaces/IPancakeSwapFeature.sol";
 import "./features/interfaces/ILiquidityProviderFeature.sol";
 import "./features/interfaces/INativeOrdersFeature.sol";
 import "./features/interfaces/IBatchFillNativeOrdersFeature.sol";
 import "./features/interfaces/IMultiplexFeature.sol";
+import "./features/interfaces/IOtcOrdersFeature.sol";
 
 
 /// @dev Interface for a fully featured Exchange Proxy.
@@ -40,11 +42,13 @@ interface IZeroEx is
     ITransformERC20Feature,
     IMetaTransactionsFeature,
     IUniswapFeature,
+    IUniswapV3Feature,
     IPancakeSwapFeature,
     ILiquidityProviderFeature,
     INativeOrdersFeature,
     IBatchFillNativeOrdersFeature,
-    IMultiplexFeature
+    IMultiplexFeature,
+    IOtcOrdersFeature
 {
     // solhint-disable state-visibility
 

contracts/zero-ex/contracts/src/features/BatchFillNativeOrdersFeature.sol

@@ -48,7 +48,7 @@ contract BatchFillNativeOrdersFeature is
     /// @dev Name of this feature.
     string public constant override FEATURE_NAME = "BatchFill";
     /// @dev Version of this feature.
-    uint256 public immutable override FEATURE_VERSION = _encodeVersion(1, 0, 0);
+    uint256 public immutable override FEATURE_VERSION = _encodeVersion(1, 1, 0);
 
     constructor(address zeroExAddress)
         public
@@ -170,6 +170,8 @@ contract BatchFillNativeOrdersFeature is
                         orders[i],
                         signatures[i],
                         takerTokenFillAmounts[i],
+                        msg.sender,
+                        false,
                         msg.sender
                     )
                 returns (uint128 takerTokenFilledAmount, uint128 makerTokenFilledAmount)

contracts/zero-ex/contracts/src/features/LiquidityProviderFeature.sol

@@ -108,7 +108,7 @@ contract LiquidityProviderFeature is
 
         if (!LibERC20Transformer.isTokenETH(inputToken)) {
             // Transfer input ERC20 tokens to the provider.
-            _transferERC20Tokens(
+            _transferERC20TokensFrom(
                 inputToken,
                 msg.sender,
                 address(provider),

contracts/zero-ex/contracts/src/features/MetaTransactionsFeature.sol

@@ -78,7 +78,7 @@ contract MetaTransactionsFeature is
     /// @dev Name of this feature.
     string public constant override FEATURE_NAME = "MetaTransactions";
     /// @dev Version of this feature.
-    uint256 public immutable override FEATURE_VERSION = _encodeVersion(1, 1, 1);
+    uint256 public immutable override FEATURE_VERSION = _encodeVersion(1, 2, 0);
     /// @dev EIP712 typehash of the `MetaTransactionData` struct.
     bytes32 public immutable MTX_EIP712_TYPEHASH = keccak256(
         "MetaTransactionData("
@@ -251,7 +251,7 @@ contract MetaTransactionsFeature is
 
         // Pay the fee to the sender.
         if (state.mtx.feeAmount > 0) {
-            _transferERC20Tokens(
+            _transferERC20TokensFrom(
                 state.mtx.feeToken,
                 state.mtx.signer,
                 state.sender,
@@ -415,7 +415,9 @@ contract MetaTransactionsFeature is
                     outputToken: args.outputToken,
                     inputTokenAmount: args.inputTokenAmount,
                     minOutputTokenAmount: args.minOutputTokenAmount,
-                    transformations: args.transformations
+                    transformations: args.transformations,
+                    useSelfBalance: false,
+                    recipient: state.mtx.signer
               })
             ),
             state.mtx.value
@@ -498,7 +500,9 @@ contract MetaTransactionsFeature is
                 order,
                 signature,
                 takerTokenFillAmount,
-                state.mtx.signer // taker is mtx signer
+                state.mtx.signer, // taker is mtx signer
+                false,
+                state.mtx.signer
             ),
             state.mtx.value
         );

contracts/zero-ex/contracts/src/features/MultiplexFeature.sol

@@ -1,803 +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 ^0.6.5;
-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 "../external/ILiquidityProviderSandbox.sol";
-import "../fixins/FixinCommon.sol";
-import "../fixins/FixinEIP712.sol";
-import "../fixins/FixinTokenSpender.sol";
-import "../migrations/LibMigrate.sol";
-import "../transformers/LibERC20Transformer.sol";
-import "../vendor/ILiquidityProvider.sol";
-import "../vendor/IUniswapV2Pair.sol";
-import "./interfaces/IFeature.sol";
-import "./interfaces/IMultiplexFeature.sol";
-import "./interfaces/INativeOrdersFeature.sol";
-import "./interfaces/ITransformERC20Feature.sol";
-import "./libs/LibNativeOrder.sol";
-
-
-/// @dev This feature enables efficient batch and multi-hop trades
-///      using different liquidity sources.
-contract MultiplexFeature is
-    IFeature,
-    IMultiplexFeature,
-    FixinCommon,
-    FixinEIP712,
-    FixinTokenSpender
-{
-    using LibERC20Transformer for IERC20TokenV06;
-    using LibSafeMathV06 for uint128;
-    using LibSafeMathV06 for uint256;
-
-    /// @dev Name of this feature.
-    string public constant override FEATURE_NAME = "MultiplexFeature";
-    /// @dev Version of this feature.
-    uint256 public immutable override FEATURE_VERSION = _encodeVersion(1, 0, 1);
-
-    /// @dev The WETH token contract.
-    IEtherTokenV06 private immutable weth;
-    /// @dev The sandbox contract address.
-    ILiquidityProviderSandbox public immutable sandbox;
-    // address of the UniswapV2Factory contract.
-    address private constant UNISWAP_FACTORY = 0x5C69bEe701ef814a2B6a3EDD4B1652CB9cc5aA6f;
-    // address of the (Sushiswap) UniswapV2Factory contract.
-    address private constant SUSHISWAP_FACTORY = 0xC0AEe478e3658e2610c5F7A4A2E1777cE9e4f2Ac;
-    // Init code hash of the UniswapV2Pair contract.
-    uint256 private constant UNISWAP_PAIR_INIT_CODE_HASH = 0x96e8ac4277198ff8b6f785478aa9a39f403cb768dd02cbee326c3e7da348845f;
-    // Init code hash of the (Sushiswap) UniswapV2Pair contract.
-    uint256 private constant SUSHISWAP_PAIR_INIT_CODE_HASH = 0xe18a34eb0e04b04f7a0ac29a6e80748dca96319b42c54d679cb821dca90c6303;
-
-    constructor(
-        address zeroExAddress,
-        IEtherTokenV06 weth_,
-        ILiquidityProviderSandbox sandbox_
-    )
-        public
-        FixinEIP712(zeroExAddress)
-    {
-        weth = weth_;
-        sandbox = sandbox_;
-    }
-
-    /// @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.batchFill.selector);
-        _registerFeatureFunction(this.multiHopFill.selector);
-        return LibMigrate.MIGRATE_SUCCESS;
-    }
-
-    /// @dev Executes a batch of fills selling `fillData.inputToken`
-    ///      for `fillData.outputToken` in sequence. Refer to the
-    ///      internal variant `_batchFill` for the allowed nested
-    ///      operations.
-    /// @param fillData Encodes the input/output tokens, the sell
-    ///        amount, and the nested operations for this batch fill.
-    /// @param minBuyAmount The minimum amount of `fillData.outputToken`
-    ///        to buy. Reverts if this amount is not met.
-    /// @return outputTokenAmount The amount of the output token bought.
-    function batchFill(
-        BatchFillData memory fillData,
-        uint256 minBuyAmount
-    )
-        public
-        payable
-        override
-        returns (uint256 outputTokenAmount)
-    {
-        // Cache the sender's balance of the output token.
-        outputTokenAmount = fillData.outputToken.getTokenBalanceOf(msg.sender);
-        // Cache the contract's ETH balance prior to this call.
-        uint256 ethBalanceBefore = address(this).balance.safeSub(msg.value);
-
-        // Perform the batch fill.
-        _batchFill(fillData);
-
-        // The `outputTokenAmount` returned by `_batchFill` may not
-        // be fully accurate (e.g. due to some janky token).
-        outputTokenAmount = fillData.outputToken.getTokenBalanceOf(msg.sender)
-            .safeSub(outputTokenAmount);
-        require(
-            outputTokenAmount >= minBuyAmount,
-            "MultiplexFeature::batchFill/UNDERBOUGHT"
-        );
-
-        uint256 ethBalanceAfter = address(this).balance;
-        require(
-            ethBalanceAfter >= ethBalanceBefore,
-            "MultiplexFeature::batchFill/OVERSPENT_ETH"
-        );
-        // Refund ETH
-        if (ethBalanceAfter > ethBalanceBefore) {
-            _transferEth(msg.sender, ethBalanceAfter - ethBalanceBefore);
-        }
-    }
-
-    /// @dev Executes a sequence of fills "hopping" through the
-    ///      path of tokens given by `fillData.tokens`. Refer to the
-    ///      internal variant `_multiHopFill` for the allowed nested
-    ///      operations.
-    /// @param fillData Encodes the path of tokens, the sell amount,
-    ///        and the nested operations for this multi-hop fill.
-    /// @param minBuyAmount The minimum amount of the output token
-    ///        to buy. Reverts if this amount is not met.
-    /// @return outputTokenAmount The amount of the output token bought.
-    function multiHopFill(
-        MultiHopFillData memory fillData,
-        uint256 minBuyAmount
-    )
-        public
-        payable
-        override
-        returns (uint256 outputTokenAmount)
-    {
-        IERC20TokenV06 outputToken = IERC20TokenV06(fillData.tokens[fillData.tokens.length - 1]);
-        // Cache the sender's balance of the output token.
-        outputTokenAmount = outputToken.getTokenBalanceOf(msg.sender);
-        // Cache the contract's ETH balance prior to this call.
-        uint256 ethBalanceBefore = address(this).balance.safeSub(msg.value);
-
-        // Perform the multi-hop fill. Pass in `msg.value` as the maximum
-        // allowable amount of ETH for the wrapped calls to consume.
-        _multiHopFill(fillData, msg.value);
-
-        // The `outputTokenAmount` returned by `_multiHopFill` may not
-        // be fully accurate (e.g. due to some janky token).
-        outputTokenAmount = outputToken.getTokenBalanceOf(msg.sender)
-            .safeSub(outputTokenAmount);
-        require(
-            outputTokenAmount >= minBuyAmount,
-            "MultiplexFeature::multiHopFill/UNDERBOUGHT"
-        );
-
-        uint256 ethBalanceAfter = address(this).balance;
-        require(
-            ethBalanceAfter >= ethBalanceBefore,
-            "MultiplexFeature::multiHopFill/OVERSPENT_ETH"
-        );
-        // Refund ETH
-        if (ethBalanceAfter > ethBalanceBefore) {
-            _transferEth(msg.sender, ethBalanceAfter - ethBalanceBefore);
-        }
-    }
-
-    // Similar to FQT. If `fillData.sellAmount` is set to `type(uint256).max`,
-    // this is effectively a batch fill. Otherwise it can be set to perform a
-    // market sell of some amount. Note that the `outputTokenAmount` returned
-    // by this function could theoretically be inaccurate if `msg.sender` has
-    // set a token allowance on an external contract that gets called during
-    // the execution of this function.
-    function _batchFill(BatchFillData memory fillData)
-        internal
-        returns (uint256 outputTokenAmount, uint256 remainingEth)
-    {
-        // Track the remaining ETH allocated to this call.
-        remainingEth = msg.value;
-        // Track the amount of input token sold.
-        uint256 soldAmount;
-        for (uint256 i = 0; i != fillData.calls.length; i++) {
-            // Check if we've hit our target.
-            if (soldAmount >= fillData.sellAmount) { break; }
-            WrappedBatchCall memory wrappedCall = fillData.calls[i];
-            // Compute the fill amount.
-            uint256 inputTokenAmount = LibSafeMathV06.min256(
-                wrappedCall.sellAmount,
-                fillData.sellAmount.safeSub(soldAmount)
-            );
-            if (wrappedCall.selector == INativeOrdersFeature._fillRfqOrder.selector) {
-                // Decode the RFQ order and signature.
-                (
-                    LibNativeOrder.RfqOrder memory order,
-                    LibSignature.Signature memory signature
-                ) = abi.decode(
-                    wrappedCall.data,
-                    (LibNativeOrder.RfqOrder, LibSignature.Signature)
-                );
-                if (order.expiry <= uint64(block.timestamp)) {
-                    bytes32 orderHash = _getEIP712Hash(
-                        LibNativeOrder.getRfqOrderStructHash(order)
-                    );
-                    emit ExpiredRfqOrder(
-                        orderHash,
-                        order.maker,
-                        order.expiry
-                    );
-                    continue;
-                }
-                require(
-                    order.takerToken == fillData.inputToken &&
-                    order.makerToken == fillData.outputToken,
-                    "MultiplexFeature::_batchFill/RFQ_ORDER_INVALID_TOKENS"
-                );
-                // Try filling the RFQ order. Swallows reverts.
-                try
-                    INativeOrdersFeature(address(this))._fillRfqOrder
-                        (
-                            order,
-                            signature,
-                            inputTokenAmount.safeDowncastToUint128(),
-                            msg.sender
-                        )
-                    returns (uint128 takerTokenFilledAmount, uint128 makerTokenFilledAmount)
-                {
-                    // Increment the sold and bought amounts.
-                    soldAmount = soldAmount.safeAdd(takerTokenFilledAmount);
-                    outputTokenAmount = outputTokenAmount.safeAdd(makerTokenFilledAmount);
-                } catch {}
-            } else if (wrappedCall.selector == this._sellToUniswap.selector) {
-                (address[] memory tokens, bool isSushi) = abi.decode(
-                    wrappedCall.data,
-                    (address[], bool)
-                );
-                require(
-                    tokens.length >= 2 &&
-                    tokens[0] == address(fillData.inputToken) &&
-                    tokens[tokens.length - 1] == address(fillData.outputToken),
-                    "MultiplexFeature::_batchFill/UNISWAP_INVALID_TOKENS"
-                );
-                // Perform the Uniswap/Sushiswap trade.
-                uint256 outputTokenAmount_  = _sellToUniswap(
-                    tokens,
-                    inputTokenAmount,
-                    isSushi,
-                    address(0),
-                    msg.sender
-                );
-                // Increment the sold and bought amounts.
-                soldAmount = soldAmount.safeAdd(inputTokenAmount);
-                outputTokenAmount = outputTokenAmount.safeAdd(outputTokenAmount_);
-            } else if (wrappedCall.selector == this._sellToLiquidityProvider.selector) {
-                (address provider, bytes memory auxiliaryData) = abi.decode(
-                    wrappedCall.data,
-                    (address, bytes)
-                );
-                if (fillData.inputToken.isTokenETH()) {
-                    inputTokenAmount = LibSafeMathV06.min256(
-                        inputTokenAmount,
-                        remainingEth
-                    );
-                    // Transfer the input ETH to the provider.
-                    _transferEth(payable(provider), inputTokenAmount);
-                    // Count that ETH as spent.
-                    remainingEth -= inputTokenAmount;
-                } else {
-                    // Transfer input ERC20 tokens to the provider.
-                    _transferERC20Tokens(
-                        fillData.inputToken,
-                        msg.sender,
-                        provider,
-                        inputTokenAmount
-                    );
-                }
-                // Perform the PLP trade.
-                uint256 outputTokenAmount_ = _sellToLiquidityProvider(
-                    fillData.inputToken,
-                    fillData.outputToken,
-                    inputTokenAmount,
-                    ILiquidityProvider(provider),
-                    msg.sender,
-                    auxiliaryData
-                );
-                // Increment the sold and bought amounts.
-                soldAmount = soldAmount.safeAdd(inputTokenAmount);
-                outputTokenAmount = outputTokenAmount.safeAdd(outputTokenAmount_);
-            } else if (wrappedCall.selector == ITransformERC20Feature._transformERC20.selector) {
-                ITransformERC20Feature.TransformERC20Args memory args;
-                args.taker = msg.sender;
-                args.inputToken = fillData.inputToken;
-                args.outputToken = fillData.outputToken;
-                args.inputTokenAmount = inputTokenAmount;
-                args.minOutputTokenAmount = 0;
-                uint256 ethValue;
-                (args.transformations, ethValue) = abi.decode(
-                    wrappedCall.data,
-                    (ITransformERC20Feature.Transformation[], uint256)
-                );
-                // Do not spend more than the remaining ETH.
-                ethValue = LibSafeMathV06.min256(
-                    ethValue,
-                    remainingEth
-                );
-                if (ethValue > 0) {
-                    require(
-                        args.inputToken.isTokenETH(),
-                        "MultiplexFeature::_batchFill/ETH_TRANSFORM_ONLY"
-                    );
-                }
-                try ITransformERC20Feature(address(this))._transformERC20
-                    {value: ethValue}
-                    (args)
-                    returns (uint256 outputTokenAmount_)
-                {
-                    remainingEth -= ethValue;
-                    soldAmount = soldAmount.safeAdd(inputTokenAmount);
-                    outputTokenAmount = outputTokenAmount.safeAdd(outputTokenAmount_);
-                } catch {}
-            } else if (wrappedCall.selector == this._multiHopFill.selector) {
-                MultiHopFillData memory multiHopFillData;
-                uint256 ethValue;
-                (
-                    multiHopFillData.tokens,
-                    multiHopFillData.calls,
-                    ethValue
-                ) = abi.decode(
-                    wrappedCall.data,
-                    (address[], WrappedMultiHopCall[], uint256)
-                );
-                multiHopFillData.sellAmount = inputTokenAmount;
-                // Do not spend more than the remaining ETH.
-                ethValue = LibSafeMathV06.min256(
-                    ethValue,
-                    remainingEth
-                );
-                // Subtract the ethValue allocated to the nested multi-hop fill.
-                remainingEth -= ethValue;
-                (uint256 outputTokenAmount_, uint256 leftoverEth) =
-                    _multiHopFill(multiHopFillData, ethValue);
-                // Increment the sold and bought amounts.
-                soldAmount = soldAmount.safeAdd(inputTokenAmount);
-                outputTokenAmount = outputTokenAmount.safeAdd(outputTokenAmount_);
-                // Add back any ETH that wasn't used by the nested multi-hop fill.
-                remainingEth += leftoverEth;
-            } else {
-                revert("MultiplexFeature::_batchFill/UNRECOGNIZED_SELECTOR");
-            }
-        }
-    }
-
-    // Internal variant of `multiHopFill`. This function can be nested within
-    // a `_batchFill`.
-    // This function executes a sequence of fills "hopping" through the
-    // path of tokens given by `fillData.tokens`. The nested operations that
-    // can be used as "hops" are:
-    // - WETH.deposit (wraps ETH)
-    // - WETH.withdraw (unwraps WETH)
-    // - _sellToUniswap (executes a Uniswap/Sushiswap swap)
-    // - _sellToLiquidityProvider (executes a PLP swap)
-    // - _transformERC20 (executes arbitrary ERC20 Transformations)
-    // This function optimizes the number of ERC20 transfers performed
-    // by having each hop transfer its output tokens directly to the
-    // target address of the next hop. Note that the `outputTokenAmount` returned
-    // by this function could theoretically be inaccurate if `msg.sender` has
-    // set a token allowance on an external contract that gets called during
-    // the execution of this function.
-    function _multiHopFill(MultiHopFillData memory fillData, uint256 totalEth)
-        public
-        returns (uint256 outputTokenAmount, uint256 remainingEth)
-    {
-        // There should be one call/hop between every two tokens
-        // in the path.
-        // tokens[0]––calls[0]––>tokens[1]––...––calls[n-1]––>tokens[n]
-        require(
-            fillData.tokens.length == fillData.calls.length + 1,
-            "MultiplexFeature::_multiHopFill/MISMATCHED_ARRAY_LENGTHS"
-        );
-        // Track the remaining ETH allocated to this call.
-        remainingEth = totalEth;
-        // This variable is used as the input and output amounts of
-        // each hop. After the final hop, this will contain the output
-        // amount of the multi-hop fill.
-        outputTokenAmount = fillData.sellAmount;
-        // This variable is used to cache the address to target in the
-        // next hop. See `_computeHopRecipient` for details.
-        address nextTarget;
-        for (uint256 i = 0; i != fillData.calls.length; i++) {
-            WrappedMultiHopCall memory wrappedCall = fillData.calls[i];
-            if (wrappedCall.selector == this._sellToUniswap.selector) {
-                // If the next hop supports a "transfer then execute" pattern,
-                // the recipient will not be `msg.sender`. See `_computeHopRecipient`
-                // for details.
-                address recipient = _computeHopRecipient(fillData.calls, i);
-                (address[] memory tokens, bool isSushi) = abi.decode(
-                    wrappedCall.data,
-                    (address[], bool)
-                );
-                // Perform the Uniswap/Sushiswap trade.
-                outputTokenAmount = _sellToUniswap(
-                    tokens,
-                    outputTokenAmount,
-                    isSushi,
-                    nextTarget,
-                    recipient
-                );
-                // If the recipient was not `msg.sender`, it must be the target
-                // contract for the next hop.
-                nextTarget = recipient == msg.sender ? address(0) : recipient;
-            } else if (wrappedCall.selector == this._sellToLiquidityProvider.selector) {
-                // If the next hop supports a "transfer then execute" pattern,
-                // the recipient will not be `msg.sender`. See `_computeHopRecipient`
-                // for details.
-                address recipient = _computeHopRecipient(fillData.calls, i);
-                // If `nextTarget` was not set in the previous hop, then we
-                // need to send in the input ETH/tokens to the liquidity provider
-                // contract before executing the trade.
-                if (nextTarget == address(0)) {
-                    (address provider, bytes memory auxiliaryData) = abi.decode(
-                        wrappedCall.data,
-                        (address, bytes)
-                    );
-                    // Transfer input ETH or ERC20 tokens to the liquidity
-                    // provider contract.
-                    if (IERC20TokenV06(fillData.tokens[i]).isTokenETH()) {
-                        outputTokenAmount = LibSafeMathV06.min256(
-                            outputTokenAmount,
-                            remainingEth
-                        );
-                        _transferEth(payable(provider), outputTokenAmount);
-                        remainingEth -= outputTokenAmount;
-                    } else {
-                        _transferERC20Tokens(
-                            IERC20TokenV06(fillData.tokens[i]),
-                            msg.sender,
-                            provider,
-                            outputTokenAmount
-                        );
-                    }
-                    outputTokenAmount = _sellToLiquidityProvider(
-                        IERC20TokenV06(fillData.tokens[i]),
-                        IERC20TokenV06(fillData.tokens[i + 1]),
-                        outputTokenAmount,
-                        ILiquidityProvider(provider),
-                        recipient,
-                        auxiliaryData
-                    );
-                } else {
-                    (, bytes memory auxiliaryData) = abi.decode(
-                        wrappedCall.data,
-                        (address, bytes)
-                    );
-                    // Tokens and ETH have already been transferred to
-                    // the liquidity provider contract in the previous hop.
-                    outputTokenAmount = _sellToLiquidityProvider(
-                        IERC20TokenV06(fillData.tokens[i]),
-                        IERC20TokenV06(fillData.tokens[i + 1]),
-                        outputTokenAmount,
-                        ILiquidityProvider(nextTarget),
-                        recipient,
-                        auxiliaryData
-                    );
-                }
-                // If the recipient was not `msg.sender`, it must be the target
-                // contract for the next hop.
-                nextTarget = recipient == msg.sender ? address(0) : recipient;
-            } else if (wrappedCall.selector == ITransformERC20Feature._transformERC20.selector) {
-                ITransformERC20Feature.TransformERC20Args memory args;
-                args.inputToken = IERC20TokenV06(fillData.tokens[i]);
-                args.outputToken = IERC20TokenV06(fillData.tokens[i + 1]);
-                args.minOutputTokenAmount = 0;
-                args.taker = payable(_computeHopRecipient(fillData.calls, i));
-                if (nextTarget != address(0)) {
-                    // If `nextTarget` was set in the previous hop, then the input
-                    // token was already sent to the FlashWallet. Setting
-                    // `inputTokenAmount` to 0 indicates that no tokens need to
-                    // be pulled into the FlashWallet before executing the
-                    // transformations.
-                    args.inputTokenAmount = 0;
-                } else if (
-                    args.taker != msg.sender &&
-                    !args.inputToken.isTokenETH()
-                ) {
-                    address flashWallet = address(
-                        ITransformERC20Feature(address(this)).getTransformWallet()
-                    );
-                    // The input token has _not_ already been sent to the
-                    // FlashWallet. We also want PayTakerTransformer to
-                    // send the output token to some address other than
-                    // msg.sender, so we must transfer the input token
-                    // to the FlashWallet here.
-                    _transferERC20Tokens(
-                        args.inputToken,
-                        msg.sender,
-                        flashWallet,
-                        outputTokenAmount
-                    );
-                    args.inputTokenAmount = 0;
-                } else {
-                    // Otherwise, either:
-                    // (1) args.taker == msg.sender, in which case
-                    //     `_transformERC20` will pull the input token
-                    //     into the FlashWallet, or
-                    // (2) args.inputToken == ETH_TOKEN_ADDRESS, in which
-                    //     case ETH is attached to the call and no token
-                    //     transfer occurs.
-                    args.inputTokenAmount = outputTokenAmount;
-                }
-                uint256 ethValue;
-                (args.transformations, ethValue) = abi.decode(
-                    wrappedCall.data,
-                    (ITransformERC20Feature.Transformation[], uint256)
-                );
-                // Do not spend more than the remaining ETH.
-                ethValue = LibSafeMathV06.min256(ethValue, remainingEth);
-                if (ethValue > 0) {
-                    require(
-                        args.inputToken.isTokenETH(),
-                        "MultiplexFeature::_multiHopFill/ETH_TRANSFORM_ONLY"
-                    );
-                }
-                // Call `_transformERC20`.
-                outputTokenAmount = ITransformERC20Feature(address(this))
-                    ._transformERC20{value: ethValue}(args);
-                // Decrement the remaining ETH.
-                remainingEth -= ethValue;
-                // If the recipient was not `msg.sender`, it must be the target
-                // contract for the next hop.
-                nextTarget = args.taker == msg.sender ? address(0) : args.taker;
-            } else if (wrappedCall.selector == IEtherTokenV06.deposit.selector) {
-                require(
-                    i == 0,
-                    "MultiplexFeature::_multiHopFill/DEPOSIT_FIRST_HOP_ONLY"
-                );
-                uint256 ethValue = LibSafeMathV06.min256(outputTokenAmount, remainingEth);
-                // Wrap ETH.
-                weth.deposit{value: ethValue}();
-                nextTarget = _computeHopRecipient(fillData.calls, i);
-                weth.transfer(nextTarget, ethValue);
-                remainingEth -= ethValue;
-            } else if (wrappedCall.selector == IEtherTokenV06.withdraw.selector) {
-                require(
-                    i == fillData.calls.length - 1,
-                    "MultiplexFeature::_multiHopFill/WITHDRAW_LAST_HOP_ONLY"
-                );
-                // Unwrap WETH and send to `msg.sender`.
-                weth.withdraw(outputTokenAmount);
-                _transferEth(msg.sender, outputTokenAmount);
-                nextTarget = address(0);
-            } else {
-                revert("MultiplexFeature::_multiHopFill/UNRECOGNIZED_SELECTOR");
-            }
-        }
-    }
-
-    // Similar to the UniswapFeature, but with a couple of differences:
-    // - Does not perform the transfer in if `pairAddress` is given,
-    //   which indicates that the transfer in was already performed
-    //   in the previous hop of a multi-hop fill.
-    // - Does not include a minBuyAmount check (which is performed in
-    //   either `batchFill` or `multiHopFill`).
-    // - Takes a `recipient` address parameter, so the output of the
-    //   final `swap` call can be sent to an address other than `msg.sender`.
-    function _sellToUniswap(
-        address[] memory tokens,
-        uint256 sellAmount,
-        bool isSushi,
-        address pairAddress,
-        address recipient
-    )
-        public
-        returns (uint256 outputTokenAmount)
-    {
-        require(tokens.length > 1, "MultiplexFeature::_sellToUniswap/InvalidTokensLength");
-
-        if (pairAddress == address(0)) {
-            pairAddress = _computeUniswapPairAddress(tokens[0], tokens[1], isSushi);
-            _transferERC20Tokens(
-                IERC20TokenV06(tokens[0]),
-                msg.sender,
-                pairAddress,
-                sellAmount
-            );
-        }
-
-        for (uint256 i = 0; i < tokens.length - 1; i++) {
-            (address inputToken, address outputToken) = (tokens[i], tokens[i + 1]);
-            outputTokenAmount = _computeUniswapOutputAmount(
-                pairAddress,
-                inputToken,
-                outputToken,
-                sellAmount
-            );
-            (uint256 amount0Out, uint256 amount1Out) = inputToken < outputToken
-                ? (uint256(0), outputTokenAmount)
-                : (outputTokenAmount, uint256(0));
-            address to = i < tokens.length - 2
-                ? _computeUniswapPairAddress(outputToken, tokens[i + 2], isSushi)
-                : recipient;
-            IUniswapV2Pair(pairAddress).swap(
-                amount0Out,
-                amount1Out,
-                to,
-                new bytes(0)
-            );
-            pairAddress = to;
-            sellAmount = outputTokenAmount;
-        }
-    }
-
-    // Same as the LiquidityProviderFeature, but without the transfer in
-    // (which is potentially done in the previous hop of a multi-hop fill)
-    // and without the minBuyAmount check (which is performed at the top, i.e.
-    // in either `batchFill` or `multiHopFill`).
-    function _sellToLiquidityProvider(
-        IERC20TokenV06 inputToken,
-        IERC20TokenV06 outputToken,
-        uint256 inputTokenAmount,
-        ILiquidityProvider provider,
-        address recipient,
-        bytes memory auxiliaryData
-    )
-        public
-        returns (uint256 outputTokenAmount)
-    {
-        uint256 balanceBefore = IERC20TokenV06(outputToken).getTokenBalanceOf(recipient);
-        if (IERC20TokenV06(inputToken).isTokenETH()) {
-            sandbox.executeSellEthForToken(
-                provider,
-                outputToken,
-                recipient,
-                0,
-                auxiliaryData
-            );
-        } else if (IERC20TokenV06(outputToken).isTokenETH()) {
-            sandbox.executeSellTokenForEth(
-                provider,
-                inputToken,
-                recipient,
-                0,
-                auxiliaryData
-            );
-        } else {
-            sandbox.executeSellTokenForToken(
-                provider,
-                inputToken,
-                outputToken,
-                recipient,
-                0,
-                auxiliaryData
-            );
-        }
-        outputTokenAmount = IERC20TokenV06(outputToken).getTokenBalanceOf(recipient)
-            .safeSub(balanceBefore);
-        emit LiquidityProviderSwap(
-            address(inputToken),
-            address(outputToken),
-            inputTokenAmount,
-            outputTokenAmount,
-            address(provider),
-            recipient
-        );
-        return outputTokenAmount;
-    }
-
-    function _transferEth(address payable recipient, uint256 amount)
-        private
-    {
-        (bool success,) = recipient.call{value: amount}("");
-        require(success, "MultiplexFeature::_transferEth/TRANSFER_FALIED");
-    }
-
-    // Some liquidity sources (e.g. Uniswap, Sushiswap, and PLP) can be passed
-    // a `recipient` parameter so the boguht tokens are transferred to the
-    // `recipient` address rather than `msg.sender`.
-    // Some liquidity sources (also Uniswap, Sushiswap, and PLP incidentally)
-    // support a "transfer then execute" pattern, where the token being sold
-    // can be transferred into the contract before calling a swap function to
-    // execute the trade.
-    // If the current hop in a multi-hop fill satisfies the first condition,
-    // and the next hop satisfies the second condition, the tokens bought
-    // in the current hop can be directly sent to the target contract of
-    // the next hop to save a transfer.
-    function _computeHopRecipient(
-        WrappedMultiHopCall[] memory calls,
-        uint256 i
-    )
-        private
-        view
-        returns (address recipient)
-    {
-        recipient = msg.sender;
-        if (i < calls.length - 1) {
-            WrappedMultiHopCall memory nextCall = calls[i + 1];
-            if (nextCall.selector == this._sellToUniswap.selector) {
-                (address[] memory tokens, bool isSushi) = abi.decode(
-                    nextCall.data,
-                    (address[], bool)
-                );
-                recipient = _computeUniswapPairAddress(tokens[0], tokens[1], isSushi);
-            } else if (nextCall.selector == this._sellToLiquidityProvider.selector) {
-                (recipient,) = abi.decode(
-                    nextCall.data,
-                    (address, bytes)
-                );
-            } else if (nextCall.selector == IEtherTokenV06.withdraw.selector) {
-                recipient = address(this);
-            } else if (nextCall.selector == ITransformERC20Feature._transformERC20.selector) {
-                recipient = address(
-                    ITransformERC20Feature(address(this)).getTransformWallet()
-                );
-            }
-        }
-        require(
-            recipient != address(0),
-            "MultiplexFeature::_computeHopRecipient/RECIPIENT_IS_NULL"
-        );
-    }
-
-    // Computes the the amount of output token that would be bought
-    // from Uniswap/Sushiswap given the input amount.
-    function _computeUniswapOutputAmount(
-        address pairAddress,
-        address inputToken,
-        address outputToken,
-        uint256 inputAmount
-    )
-        private
-        view
-        returns (uint256 outputAmount)
-    {
-        require(
-            inputAmount > 0,
-            "MultiplexFeature::_computeUniswapOutputAmount/INSUFFICIENT_INPUT_AMOUNT"
-        );
-        (uint256 reserve0, uint256 reserve1,) = IUniswapV2Pair(pairAddress).getReserves();
-        require(
-            reserve0 > 0 && reserve1 > 0,
-            'MultiplexFeature::_computeUniswapOutputAmount/INSUFFICIENT_LIQUIDITY'
-        );
-        (uint256 inputReserve, uint256 outputReserve) = inputToken < outputToken
-            ? (reserve0, reserve1)
-            : (reserve1, reserve0);
-        uint256 inputAmountWithFee = inputAmount.safeMul(997);
-        uint256 numerator = inputAmountWithFee.safeMul(outputReserve);
-        uint256 denominator = inputReserve.safeMul(1000).safeAdd(inputAmountWithFee);
-        return numerator / denominator;
-    }
-
-    // Computes the Uniswap/Sushiswap pair contract address for the
-    // given tokens.
-    function _computeUniswapPairAddress(
-        address tokenA,
-        address tokenB,
-        bool isSushi
-    )
-        private
-        pure
-        returns (address pairAddress)
-    {
-        (address token0, address token1) = tokenA < tokenB
-            ? (tokenA, tokenB)
-            : (tokenB, tokenA);
-        if (isSushi) {
-            return address(uint256(keccak256(abi.encodePacked(
-                hex'ff',
-                SUSHISWAP_FACTORY,
-                keccak256(abi.encodePacked(token0, token1)),
-                SUSHISWAP_PAIR_INIT_CODE_HASH
-            ))));
-        } else {
-            return address(uint256(keccak256(abi.encodePacked(
-                hex'ff',
-                UNISWAP_FACTORY,
-                keccak256(abi.encodePacked(token0, token1)),
-                UNISWAP_PAIR_INIT_CODE_HASH
-            ))));
-        }
-    }
-}

contracts/zero-ex/contracts/src/features/NativeOrdersFeature.sol

@@ -34,7 +34,7 @@ contract NativeOrdersFeature is
     /// @dev Name of this feature.
     string public constant override FEATURE_NAME = "LimitOrders";
     /// @dev Version of this feature.
-    uint256 public immutable override FEATURE_VERSION = _encodeVersion(1, 2, 0);
+    uint256 public immutable override FEATURE_VERSION = _encodeVersion(1, 3, 0);
 
     constructor(
         address zeroExAddress,

contracts/zero-ex/contracts/src/features/OtcOrdersFeature.sol

@@ -0,0 +1,637 @@
+// 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/IEtherTokenV06.sol";
+import "@0x/contracts-utils/contracts/src/v06/LibSafeMathV06.sol";
+import "@0x/contracts-utils/contracts/src/v06/LibMathV06.sol";
+import "../errors/LibNativeOrdersRichErrors.sol";
+import "../fixins/FixinCommon.sol";
+import "../fixins/FixinEIP712.sol";
+import "../fixins/FixinTokenSpender.sol";
+import "../migrations/LibMigrate.sol";
+import "../storage/LibNativeOrdersStorage.sol";
+import "../storage/LibOtcOrdersStorage.sol";
+import "./interfaces/IFeature.sol";
+import "./interfaces/IOtcOrdersFeature.sol";
+import "./libs/LibNativeOrder.sol";
+import "./libs/LibSignature.sol";
+
+
+/// @dev Feature for interacting with OTC orders.
+contract OtcOrdersFeature is
+    IFeature,
+    IOtcOrdersFeature,
+    FixinCommon,
+    FixinEIP712,
+    FixinTokenSpender
+{
+    using LibSafeMathV06 for uint256;
+    using LibSafeMathV06 for uint128;
+
+    /// @dev Name of this feature.
+    string public constant override FEATURE_NAME = "OtcOrders";
+    /// @dev Version of this feature.
+    uint256 public immutable override FEATURE_VERSION = _encodeVersion(1, 0, 0);
+    /// @dev ETH pseudo-token address.
+    address constant private ETH_TOKEN_ADDRESS = 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE;
+    /// @dev The WETH token contract.
+    IEtherTokenV06 private immutable WETH;
+
+    constructor(address zeroExAddress, IEtherTokenV06 weth)
+        public
+        FixinEIP712(zeroExAddress)
+    {
+        WETH = 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.fillOtcOrder.selector);
+        _registerFeatureFunction(this.fillOtcOrderForEth.selector);
+        _registerFeatureFunction(this.fillOtcOrderWithEth.selector);
+        _registerFeatureFunction(this.fillTakerSignedOtcOrderForEth.selector);
+        _registerFeatureFunction(this.fillTakerSignedOtcOrder.selector);
+        _registerFeatureFunction(this.batchFillTakerSignedOtcOrders.selector);
+        _registerFeatureFunction(this._fillOtcOrder.selector);
+        _registerFeatureFunction(this.getOtcOrderInfo.selector);
+        _registerFeatureFunction(this.getOtcOrderHash.selector);
+        _registerFeatureFunction(this.lastOtcTxOriginNonce.selector);
+        return LibMigrate.MIGRATE_SUCCESS;
+    }
+
+    /// @dev Fill an OTC order for up to `takerTokenFillAmount` taker tokens.
+    /// @param order The OTC order.
+    /// @param makerSignature The order signature from the maker.
+    /// @param takerTokenFillAmount Maximum taker token amount to fill this
+    ///        order with.
+    /// @return takerTokenFilledAmount How much taker token was filled.
+    /// @return makerTokenFilledAmount How much maker token was filled.
+    function fillOtcOrder(
+        LibNativeOrder.OtcOrder memory order,
+        LibSignature.Signature memory makerSignature,
+        uint128 takerTokenFillAmount
+    )
+        public
+        override
+        returns (uint128 takerTokenFilledAmount, uint128 makerTokenFilledAmount)
+    {
+        LibNativeOrder.OtcOrderInfo memory orderInfo = getOtcOrderInfo(order);
+        _validateOtcOrder(
+            order, 
+            orderInfo,
+            makerSignature,
+            msg.sender
+        );
+        (takerTokenFilledAmount, makerTokenFilledAmount) = _settleOtcOrder(
+            order,
+            takerTokenFillAmount,
+            msg.sender,
+            msg.sender
+        );
+
+        emit OtcOrderFilled(
+            orderInfo.orderHash,
+            order.maker,
+            msg.sender,
+            address(order.makerToken),
+            address(order.takerToken),
+            makerTokenFilledAmount,
+            takerTokenFilledAmount
+        );
+    }
+
+    /// @dev Fill an OTC order for up to `takerTokenFillAmount` taker tokens.
+    ///      Unwraps bought WETH into ETH. before sending it to 
+    ///      the taker.
+    /// @param order The OTC order.
+    /// @param makerSignature The order signature from the maker.
+    /// @param takerTokenFillAmount Maximum taker token amount to fill this
+    ///        order with.
+    /// @return takerTokenFilledAmount How much taker token was filled.
+    /// @return makerTokenFilledAmount How much maker token was filled.
+    function fillOtcOrderForEth(
+        LibNativeOrder.OtcOrder memory order,
+        LibSignature.Signature memory makerSignature,
+        uint128 takerTokenFillAmount
+    )
+        public
+        override
+        returns (uint128 takerTokenFilledAmount, uint128 makerTokenFilledAmount)
+    {
+        require(
+            order.makerToken == WETH,
+            "OtcOrdersFeature::fillOtcOrderForEth/MAKER_TOKEN_NOT_WETH"
+        );
+        LibNativeOrder.OtcOrderInfo memory orderInfo = getOtcOrderInfo(order);
+        _validateOtcOrder(
+            order, 
+            orderInfo,
+            makerSignature,
+            msg.sender
+        );
+        (takerTokenFilledAmount, makerTokenFilledAmount) = _settleOtcOrder(
+            order,
+            takerTokenFillAmount, 
+            msg.sender,
+            address(this)
+        );
+        // Unwrap WETH
+        WETH.withdraw(makerTokenFilledAmount);
+        // Transfer ETH to taker
+        _transferEth(msg.sender, makerTokenFilledAmount);
+
+        emit OtcOrderFilled(
+            orderInfo.orderHash,
+            order.maker,
+            msg.sender,
+            address(order.makerToken),
+            address(order.takerToken),
+            makerTokenFilledAmount,
+            takerTokenFilledAmount
+        );
+    }
+
+    /// @dev Fill an OTC order whose taker token is WETH for up
+    ///      to `msg.value`.
+    /// @param order The OTC order.
+    /// @param makerSignature The order signature from the maker.
+    /// @return takerTokenFilledAmount How much taker token was filled.
+    /// @return makerTokenFilledAmount How much maker token was filled.
+    function fillOtcOrderWithEth(
+        LibNativeOrder.OtcOrder memory order,
+        LibSignature.Signature memory makerSignature
+    )
+        public
+        override
+        payable
+        returns (uint128 takerTokenFilledAmount, uint128 makerTokenFilledAmount)
+    {
+        if (order.takerToken == WETH) {
+            // Wrap ETH
+            WETH.deposit{value: msg.value}();
+        } else {
+            require(
+                address(order.takerToken) == ETH_TOKEN_ADDRESS,
+                "OtcOrdersFeature::fillOtcOrderWithEth/INVALID_TAKER_TOKEN"
+            );
+        }
+
+        LibNativeOrder.OtcOrderInfo memory orderInfo = getOtcOrderInfo(order);
+        _validateOtcOrder(
+            order, 
+            orderInfo,
+            makerSignature,
+            msg.sender
+        );
+
+        (takerTokenFilledAmount, makerTokenFilledAmount) =  _settleOtcOrder(
+            order,
+            msg.value.safeDowncastToUint128(),
+            address(this),
+            msg.sender
+        );
+        if (takerTokenFilledAmount < msg.value) {
+            uint256 refundAmount = msg.value - uint256(takerTokenFilledAmount);
+            if (order.takerToken == WETH) {
+                WETH.withdraw(refundAmount);
+            }
+            // Refund unused ETH
+            _transferEth(msg.sender, refundAmount);
+        }
+
+        emit OtcOrderFilled(
+            orderInfo.orderHash,
+            order.maker,
+            msg.sender,
+            address(order.makerToken),
+            address(order.takerToken),
+            makerTokenFilledAmount,
+            takerTokenFilledAmount
+        );
+    }
+
+    /// @dev Fully fill an OTC order. "Meta-transaction" variant,
+    ///      requires order to be signed by both maker and taker.
+    /// @param order The OTC order.
+    /// @param makerSignature The order signature from the maker.
+    /// @param takerSignature The order signature from the taker.
+    function fillTakerSignedOtcOrder(
+        LibNativeOrder.OtcOrder memory order,
+        LibSignature.Signature memory makerSignature,
+        LibSignature.Signature memory takerSignature
+    )
+        public
+        override
+    {
+        LibNativeOrder.OtcOrderInfo memory orderInfo = getOtcOrderInfo(order);
+        address taker = LibSignature.getSignerOfHash(orderInfo.orderHash, takerSignature);
+        
+        _validateOtcOrder(
+            order, 
+            orderInfo,
+            makerSignature,
+            taker
+        );
+        _settleOtcOrder(
+            order,
+            order.takerAmount,
+            taker,
+            taker
+        );
+
+        emit OtcOrderFilled(
+            orderInfo.orderHash,
+            order.maker,
+            taker,
+            address(order.makerToken),
+            address(order.takerToken),
+            order.makerAmount,
+            order.takerAmount
+        );
+    }
+
+    /// @dev Fully fill an OTC order. "Meta-transaction" variant,
+    ///      requires order to be signed by both maker and taker.
+    ///      Unwraps bought WETH into ETH. before sending it to 
+    ///      the taker.
+    /// @param order The OTC order.
+    /// @param makerSignature The order signature from the maker.
+    /// @param takerSignature The order signature from the taker.
+    function fillTakerSignedOtcOrderForEth(
+        LibNativeOrder.OtcOrder memory order,
+        LibSignature.Signature memory makerSignature,
+        LibSignature.Signature memory takerSignature
+    )
+        public
+        override
+    {
+        require(
+            order.makerToken == WETH,
+            "OtcOrdersFeature::fillTakerSignedOtcOrder/MAKER_TOKEN_NOT_WETH"
+        );
+        LibNativeOrder.OtcOrderInfo memory orderInfo = getOtcOrderInfo(order);
+        address taker = LibSignature.getSignerOfHash(orderInfo.orderHash, takerSignature);
+        
+        _validateOtcOrder(
+            order, 
+            orderInfo,
+            makerSignature,
+            taker
+        );
+        _settleOtcOrder(
+            order,
+            order.takerAmount,
+            taker,
+            address(this)
+        );
+        // Unwrap WETH
+        WETH.withdraw(order.makerAmount);
+        // Transfer ETH to taker
+        _transferEth(taker, order.makerAmount);
+
+        emit OtcOrderFilled(
+            orderInfo.orderHash,
+            order.maker,
+            taker,
+            address(order.makerToken),
+            address(order.takerToken),
+            order.makerAmount,
+            order.takerAmount
+        );
+    }
+
+    /// @dev Fills multiple taker-signed OTC orders.
+    /// @param orders Array of OTC orders.
+    /// @param makerSignatures Array of maker signatures for each order.
+    /// @param takerSignatures Array of taker signatures for each order.
+    /// @param unwrapWeth Array of booleans representing whether or not 
+    ///        to unwrap bought WETH into ETH for each order. Should be set 
+    ///        to false if the maker token is not WETH.
+    /// @return successes Array of booleans representing whether or not
+    ///         each order in `orders` was filled successfully.
+    function batchFillTakerSignedOtcOrders(
+        LibNativeOrder.OtcOrder[] memory orders,
+        LibSignature.Signature[] memory makerSignatures,
+        LibSignature.Signature[] memory takerSignatures,
+        bool[] memory unwrapWeth
+    )
+        public
+        override
+        returns (bool[] memory successes)
+    {
+        require(
+            orders.length == makerSignatures.length && 
+            orders.length == takerSignatures.length &&
+            orders.length == unwrapWeth.length,
+            "OtcOrdersFeature::batchFillTakerSignedOtcOrders/MISMATCHED_ARRAY_LENGTHS"
+        );
+        successes = new bool[](orders.length);
+        for (uint256 i = 0; i != orders.length; i++) {
+            bytes4 fnSelector = unwrapWeth[i] 
+                ? this.fillTakerSignedOtcOrderForEth.selector
+                : this.fillTakerSignedOtcOrder.selector;
+            // Swallow reverts
+            (successes[i], ) = _implementation.delegatecall(
+                abi.encodeWithSelector(
+                    fnSelector,
+                    orders[i],
+                    makerSignatures[i],
+                    takerSignatures[i]
+                )
+            );
+        }
+    }
+
+    /// @dev Fill an OTC order for up to `takerTokenFillAmount` taker tokens.
+    ///      Internal variant.
+    /// @param order The OTC order.
+    /// @param makerSignature The order signature from the maker.
+    /// @param takerTokenFillAmount Maximum taker token amount to fill this
+    ///        order with.
+    /// @param taker The address to fill the order in the context of.
+    /// @param useSelfBalance Whether to use the Exchange Proxy's balance
+    ///        of input tokens.
+    /// @param recipient The recipient of the bought maker tokens.
+    /// @return takerTokenFilledAmount How much taker token was filled.
+    /// @return makerTokenFilledAmount How much maker token was filled.
+    function _fillOtcOrder(
+        LibNativeOrder.OtcOrder memory order,
+        LibSignature.Signature memory makerSignature,
+        uint128 takerTokenFillAmount,
+        address taker,
+        bool useSelfBalance,
+        address recipient
+    )
+        public
+        override
+        onlySelf
+        returns (uint128 takerTokenFilledAmount, uint128 makerTokenFilledAmount)
+    {
+        LibNativeOrder.OtcOrderInfo memory orderInfo = getOtcOrderInfo(order);
+        _validateOtcOrder(
+            order, 
+            orderInfo,
+            makerSignature,
+            taker
+        );
+        (takerTokenFilledAmount, makerTokenFilledAmount) = _settleOtcOrder(
+            order,
+            takerTokenFillAmount,
+            useSelfBalance ? address(this) : taker,
+            recipient
+        );
+
+        emit OtcOrderFilled(
+            orderInfo.orderHash,
+            order.maker,
+            taker,
+            address(order.makerToken),
+            address(order.takerToken),
+            makerTokenFilledAmount,
+            takerTokenFilledAmount
+        );
+    }
+
+    /// @dev Validates an OTC order, reverting if the order cannot be 
+    ///      filled by the given taker.
+    /// @param order The OTC order.
+    /// @param orderInfo Info on the order.
+    /// @param makerSignature The order signature from the maker.
+    /// @param taker The order taker.
+    function _validateOtcOrder(
+        LibNativeOrder.OtcOrder memory order,
+        LibNativeOrder.OtcOrderInfo memory orderInfo,
+        LibSignature.Signature memory makerSignature,
+        address taker
+    )
+        private
+        view
+    {
+        // Must be fillable.
+        if (orderInfo.status != LibNativeOrder.OrderStatus.FILLABLE) {
+            LibNativeOrdersRichErrors.OrderNotFillableError(
+                orderInfo.orderHash,
+                uint8(orderInfo.status)
+            ).rrevert();
+        }
+
+        // Must be a valid taker for the order.
+        if (order.taker != address(0) && order.taker != taker) {
+            LibNativeOrdersRichErrors.OrderNotFillableByTakerError(
+                orderInfo.orderHash,
+                taker,
+                order.taker
+            ).rrevert();
+        }
+
+        LibNativeOrdersStorage.Storage storage stor =
+            LibNativeOrdersStorage.getStorage();
+
+        // Must be fillable by the tx.origin.
+        if (
+            order.txOrigin != tx.origin &&
+            !stor.originRegistry[order.txOrigin][tx.origin]
+        ) {
+            LibNativeOrdersRichErrors.OrderNotFillableByOriginError(
+                orderInfo.orderHash,
+                tx.origin,
+                order.txOrigin
+            ).rrevert();
+        }
+
+        // Maker signature must be valid for the order.
+        address makerSigner = LibSignature.getSignerOfHash(orderInfo.orderHash, makerSignature);
+        if (
+            makerSigner != order.maker &&
+            !stor.orderSignerRegistry[order.maker][makerSigner]
+        ) {
+            LibNativeOrdersRichErrors.OrderNotSignedByMakerError(
+                orderInfo.orderHash,
+                makerSigner,
+                order.maker
+            ).rrevert();
+        }
+    }
+
+    /// @dev Settle the trade between an OTC order's maker and taker.
+    /// @param order The OTC order.
+    /// @param takerTokenFillAmount Maximum taker token amount to fill this
+    ///        order with.
+    /// @param payer The address holding the taker tokens.
+    /// @param recipient The recipient of the maker tokens.
+    /// @return takerTokenFilledAmount How much taker token was filled.
+    /// @return makerTokenFilledAmount How much maker token was filled.
+    function _settleOtcOrder(
+        LibNativeOrder.OtcOrder memory order,
+        uint128 takerTokenFillAmount,
+        address payer,
+        address recipient
+    )
+        private
+        returns (uint128 takerTokenFilledAmount, uint128 makerTokenFilledAmount)
+    {
+        {
+            // Unpack nonce fields
+            uint64 nonceBucket = uint64(order.expiryAndNonce >> 128);
+            uint128 nonce = uint128(order.expiryAndNonce);
+            // Update tx origin nonce for the order
+            LibOtcOrdersStorage.getStorage().txOriginNonces
+                [order.txOrigin][nonceBucket] = nonce;
+        }
+
+        if (takerTokenFillAmount == order.takerAmount) {
+            takerTokenFilledAmount = order.takerAmount;
+            makerTokenFilledAmount = order.makerAmount;
+        } else {
+            // Clamp the taker token fill amount to the fillable amount.
+            takerTokenFilledAmount = LibSafeMathV06.min128(
+                takerTokenFillAmount,
+                order.takerAmount
+            );
+            // Compute the maker token amount.
+            // This should never overflow because the values are all clamped to
+            // (2^128-1).
+            makerTokenFilledAmount = uint128(LibMathV06.getPartialAmountFloor(
+                uint256(takerTokenFilledAmount),
+                uint256(order.takerAmount),
+                uint256(order.makerAmount)
+            ));
+        }
+
+        if (payer == address(this)) {
+            if (address(order.takerToken) == ETH_TOKEN_ADDRESS) {
+                // Transfer ETH to the maker.
+                payable(order.maker).transfer(takerTokenFilledAmount);
+            } else {
+                // Transfer this -> maker.
+                _transferERC20Tokens(
+                    order.takerToken,
+                    order.maker,
+                    takerTokenFilledAmount
+                );                
+            }
+        } else {
+            // Transfer taker -> maker
+            _transferERC20TokensFrom(
+                order.takerToken,
+                payer,
+                order.maker,
+                takerTokenFilledAmount
+            );
+        }
+        // Transfer maker -> recipient.
+        _transferERC20TokensFrom(
+            order.makerToken,
+            order.maker,
+            recipient,
+            makerTokenFilledAmount
+        );
+    }
+
+    /// @dev Get the order info for an OTC order.
+    /// @param order The OTC order.
+    /// @return orderInfo Info about the order.
+    function getOtcOrderInfo(LibNativeOrder.OtcOrder memory order)
+        public
+        override
+        view
+        returns (LibNativeOrder.OtcOrderInfo memory orderInfo)
+    {
+        // compute order hash.
+        orderInfo.orderHash = getOtcOrderHash(order);
+
+        LibOtcOrdersStorage.Storage storage stor =
+            LibOtcOrdersStorage.getStorage();
+
+        // Unpack expiry and nonce fields
+        uint64 expiry = uint64(order.expiryAndNonce >> 192);
+        uint64 nonceBucket = uint64(order.expiryAndNonce >> 128);
+        uint128 nonce = uint128(order.expiryAndNonce);
+
+        // check tx origin nonce
+        uint128 lastNonce = stor.txOriginNonces
+            [order.txOrigin]
+            [nonceBucket];
+        if (nonce <= lastNonce) {
+            orderInfo.status = LibNativeOrder.OrderStatus.INVALID;
+            return orderInfo;
+        }
+
+        // Check for expiration.
+        if (expiry <= uint64(block.timestamp)) {
+            orderInfo.status = LibNativeOrder.OrderStatus.EXPIRED;
+            return orderInfo;
+        }
+
+        orderInfo.status = LibNativeOrder.OrderStatus.FILLABLE;
+        return orderInfo;
+    }
+
+    /// @dev Get the canonical hash of an OTC order.
+    /// @param order The OTC order.
+    /// @return orderHash The order hash.
+    function getOtcOrderHash(LibNativeOrder.OtcOrder memory order)
+        public
+        override
+        view
+        returns (bytes32 orderHash)
+    {
+        return _getEIP712Hash(
+            LibNativeOrder.getOtcOrderStructHash(order)
+        );
+    }
+
+    /// @dev Get the last nonce used for a particular
+    ///      tx.origin address and nonce bucket.
+    /// @param txOrigin The address.
+    /// @param nonceBucket The nonce bucket index.
+    /// @return lastNonce The last nonce value used.
+    function lastOtcTxOriginNonce(address txOrigin, uint64 nonceBucket)
+        public
+        override
+        view
+        returns (uint128 lastNonce)
+    {
+        LibOtcOrdersStorage.Storage storage stor =
+            LibOtcOrdersStorage.getStorage();
+        return stor.txOriginNonces
+            [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();
+        }
+    }
+}

contracts/zero-ex/contracts/src/features/TransformERC20Feature.sol

@@ -22,6 +22,7 @@ pragma experimental ABIEncoderV2;
 
 import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
 import "@0x/contracts-erc20/contracts/src/v06/LibERC20TokenV06.sol";
+import "@0x/contracts-utils/contracts/src/v06/LibBytesV06.sol";
 import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
 import "@0x/contracts-utils/contracts/src/v06/LibSafeMathV06.sol";
 import "../errors/LibTransformERC20RichErrors.sol";
@@ -51,16 +52,14 @@ contract TransformERC20Feature is
     struct TransformERC20PrivateState {
         IFlashWallet wallet;
         address transformerDeployer;
-        uint256 takerOutputTokenBalanceBefore;
-        uint256 takerOutputTokenBalanceAfter;
+        uint256 recipientOutputTokenBalanceBefore;
+        uint256 recipientOutputTokenBalanceAfter;
     }
 
     /// @dev Name of this feature.
     string public constant override FEATURE_NAME = "TransformERC20";
     /// @dev Version of this feature.
-    uint256 public immutable override FEATURE_VERSION = _encodeVersion(1, 3, 1);
-
-    constructor() public {}
+    uint256 public immutable override FEATURE_VERSION = _encodeVersion(1, 4, 0);
 
     /// @dev Initialize and register this feature.
     ///      Should be delegatecalled by `Migrate.migrate()`.
@@ -76,7 +75,7 @@ contract TransformERC20Feature is
         _registerFeatureFunction(this.setTransformerDeployer.selector);
         _registerFeatureFunction(this.setQuoteSigner.selector);
         _registerFeatureFunction(this.getQuoteSigner.selector);
-        _registerFeatureFunction(this.transformERC20.selector);
+        _registerFeatureFunction(this.transformERC20Staging.selector);
         _registerFeatureFunction(this._transformERC20.selector);
         if (this.getTransformWallet() == IFlashWallet(address(0))) {
             // Create the transform wallet if it doesn't exist.
@@ -146,6 +145,44 @@ contract TransformERC20Feature is
         LibTransformERC20Storage.getStorage().wallet = wallet;
     }
 
+    /// @dev Wrapper for `transformERC20`. This selector will be temporarily
+    ///      registered to the Exchange Proxy so that we can migrate 0x API
+    ///      with no downtime. Once 0x API has been updated to point to this
+    ///      function, we can safely re-register `transformERC20`, point 
+    ///      0x API back to `transformERC20`, and deregister this function.
+    /// @param inputToken The token being provided by the sender.
+    ///        If `0xeee...`, ETH is implied and should be provided with the call.`
+    /// @param outputToken The token to be acquired by the sender.
+    ///        `0xeee...` implies ETH.
+    /// @param inputTokenAmount The amount of `inputToken` to take from the sender.
+    ///        If set to `uint256(-1)`, the entire spendable balance of the taker
+    ///        will be solt.
+    /// @param minOutputTokenAmount The minimum amount of `outputToken` the sender
+    ///        must receive for the entire transformation to succeed. If set to zero,
+    ///        the minimum output token transfer will not be asserted.
+    /// @param transformations The transformations to execute on the token balance(s)
+    ///        in sequence.
+    /// @return outputTokenAmount The amount of `outputToken` received by the sender.
+    function transformERC20Staging(
+        IERC20TokenV06 inputToken,
+        IERC20TokenV06 outputToken,
+        uint256 inputTokenAmount,
+        uint256 minOutputTokenAmount,
+        Transformation[] memory transformations
+    )
+        public
+        payable
+        returns (uint256 outputTokenAmount)
+    {
+        return transformERC20(
+            inputToken, 
+            outputToken, 
+            inputTokenAmount, 
+            minOutputTokenAmount, 
+            transformations
+        );
+    }
+
     /// @dev Executes a series of transformations to convert an ERC20 `inputToken`
     ///      to an ERC20 `outputToken`.
     /// @param inputToken The token being provided by the sender.
@@ -180,7 +217,9 @@ contract TransformERC20Feature is
                 outputToken: outputToken,
                 inputTokenAmount: inputTokenAmount,
                 minOutputTokenAmount: minOutputTokenAmount,
-                transformations: transformations
+                transformations: transformations,
+                useSelfBalance: false,
+                recipient: msg.sender
             })
         );
     }
@@ -208,7 +247,7 @@ contract TransformERC20Feature is
     {
         // If the input token amount is -1 and we are not selling ETH,
         // transform the taker's entire spendable balance.
-        if (args.inputTokenAmount == uint256(-1)) {
+        if (!args.useSelfBalance && args.inputTokenAmount == uint256(-1)) {
             if (LibERC20Transformer.isTokenETH(args.inputToken)) {
                 // We can't pull more ETH from the taker, so we just set the
                 // input token amount to the value attached to the call.
@@ -225,17 +264,12 @@ contract TransformERC20Feature is
         state.wallet = getTransformWallet();
         state.transformerDeployer = getTransformerDeployer();
 
-        // Remember the initial output token balance of the taker.
-        state.takerOutputTokenBalanceBefore =
-            LibERC20Transformer.getTokenBalanceOf(args.outputToken, args.taker);
+        // Remember the initial output token balance of the recipient.
+        state.recipientOutputTokenBalanceBefore =
+            LibERC20Transformer.getTokenBalanceOf(args.outputToken, args.recipient);
 
         // Pull input tokens from the taker to the wallet and transfer attached ETH.
-        _transferInputTokensAndAttachedEth(
-            args.inputToken,
-            args.taker,
-            address(state.wallet),
-            args.inputTokenAmount
-        );
+        _transferInputTokensAndAttachedEth(args, address(state.wallet));
 
         {
             // Perform transformations.
@@ -244,22 +278,29 @@ contract TransformERC20Feature is
                     state.wallet,
                     args.transformations[i],
                     state.transformerDeployer,
-                    args.taker
+                    args.recipient
                 );
             }
+            // Transfer output tokens from wallet to recipient
+            outputTokenAmount = _executeOutputTokenTransfer(
+                args.outputToken, 
+                state.wallet, 
+                args.recipient
+            );
         }
 
-        // Compute how much output token has been transferred to the taker.
-        state.takerOutputTokenBalanceAfter =
-            LibERC20Transformer.getTokenBalanceOf(args.outputToken, args.taker);
-        if (state.takerOutputTokenBalanceAfter < state.takerOutputTokenBalanceBefore) {
+        // Compute how much output token has been transferred to the recipient.
+        state.recipientOutputTokenBalanceAfter =
+            LibERC20Transformer.getTokenBalanceOf(args.outputToken, args.recipient);
+        if (state.recipientOutputTokenBalanceAfter < state.recipientOutputTokenBalanceBefore) {
             LibTransformERC20RichErrors.NegativeTransformERC20OutputError(
                 address(args.outputToken),
-                state.takerOutputTokenBalanceBefore - state.takerOutputTokenBalanceAfter
+                state.recipientOutputTokenBalanceBefore - state.recipientOutputTokenBalanceAfter
             ).rrevert();
         }
-        outputTokenAmount = state.takerOutputTokenBalanceAfter.safeSub(
-            state.takerOutputTokenBalanceBefore
+        outputTokenAmount = LibSafeMathV06.min256(
+            outputTokenAmount,
+            state.recipientOutputTokenBalanceAfter.safeSub(state.recipientOutputTokenBalanceBefore)
         );
         // Ensure enough output token has been sent to the taker.
         if (outputTokenAmount < args.minOutputTokenAmount) {
@@ -292,38 +333,49 @@ contract TransformERC20Feature is
         return LibTransformERC20Storage.getStorage().wallet;
     }
 
-    /// @dev Transfer input tokens from the taker and any attached ETH to `to`
-    /// @param inputToken The token to pull from the taker.
-    /// @param from The from (taker) address.
+    /// @dev Transfer input tokens and any attached ETH to `to`
+    /// @param args A `TransformERC20Args` struct.
     /// @param to The recipient of tokens and ETH.
-    /// @param amount Amount of `inputToken` tokens to transfer.
     function _transferInputTokensAndAttachedEth(
-        IERC20TokenV06 inputToken,
-        address from,
-        address payable to,
-        uint256 amount
+        TransformERC20Args memory args,
+        address payable to
     )
         private
     {
+        if (
+            LibERC20Transformer.isTokenETH(args.inputToken) &&
+            msg.value < args.inputTokenAmount
+        ) {
+             // Token is ETH, so the caller must attach enough ETH to the call.
+            LibTransformERC20RichErrors.InsufficientEthAttachedError(
+                msg.value,
+                args.inputTokenAmount
+            ).rrevert();
+        }
+
         // Transfer any attached ETH.
         if (msg.value != 0) {
             to.transfer(msg.value);
         }
+
         // Transfer input tokens.
-        if (!LibERC20Transformer.isTokenETH(inputToken) && amount != 0) {
-            // Token is not ETH, so pull ERC20 tokens.
-            _transferERC20Tokens(
-                inputToken,
-                from,
-                to,
-                amount
-            );
-        } else if (msg.value < amount) {
-             // Token is ETH, so the caller must attach enough ETH to the call.
-            LibTransformERC20RichErrors.InsufficientEthAttachedError(
-                msg.value,
-                amount
-            ).rrevert();
+        if (!LibERC20Transformer.isTokenETH(args.inputToken)) {
+            if (args.useSelfBalance) {
+                // Use EP balance input token.
+                _transferERC20Tokens(
+                    args.inputToken,
+                    to,
+                    args.inputTokenAmount
+                );
+            } else {
+                // Pull ERC20 tokens from taker.
+                _transferERC20TokensFrom(
+                    args.inputToken,
+                    args.taker,
+                    to,
+                    args.inputTokenAmount
+                );
+            }
         }
     }
 
@@ -331,12 +383,12 @@ contract TransformERC20Feature is
     /// @param wallet The wallet instance.
     /// @param transformation The transformation.
     /// @param transformerDeployer The address of the transformer deployer.
-    /// @param taker The taker address.
+    /// @param recipient The recipient address.
     function _executeTransformation(
         IFlashWallet wallet,
         Transformation memory transformation,
         address transformerDeployer,
-        address payable taker
+        address payable recipient
     )
         private
     {
@@ -354,7 +406,7 @@ contract TransformERC20Feature is
                 IERC20Transformer.transform.selector,
                 IERC20Transformer.TransformContext({
                     sender: msg.sender,
-                    taker: taker,
+                    recipient: recipient,
                     data: transformation.data
                 })
             )
@@ -370,4 +422,52 @@ contract TransformERC20Feature is
             ).rrevert();
         }
     }
+
+    function _executeOutputTokenTransfer(
+        IERC20TokenV06 outputToken,
+        IFlashWallet wallet,
+        address payable recipient
+    )
+        private
+        returns (uint256 transferAmount)
+    {
+        transferAmount =
+            LibERC20Transformer.getTokenBalanceOf(outputToken, address(wallet));
+        if (LibERC20Transformer.isTokenETH(outputToken)) {
+            wallet.executeCall(
+                recipient,
+                "",
+                transferAmount
+            );
+        } else {
+            bytes memory resultData = wallet.executeCall(
+                payable(address(outputToken)),
+                abi.encodeWithSelector(
+                    IERC20TokenV06.transfer.selector,
+                    recipient,
+                    transferAmount
+                ),
+                0
+            );
+            if (resultData.length == 0) {
+                // If we get back 0 returndata, this may be a non-standard ERC-20 that
+                // does not return a boolean. Check that it at least contains code.
+                uint256 size;
+                assembly { size := extcodesize(outputToken) }
+                require(size > 0, "invalid token address, contains no code");
+            } else if (resultData.length >= 32) {
+                // If we get back at least 32 bytes, we know the target address
+                // contains code, and we assume it is a token that returned a boolean
+                // success value, which must be true.
+                uint256 result = LibBytesV06.readUint256(resultData, 0);
+                if (result != 1) {
+                    LibRichErrorsV06.rrevert(resultData);
+                }
+            } else {
+                // If 0 < returndatasize < 32, the target is a contract, but not a
+                // valid token.
+                LibRichErrorsV06.rrevert(resultData);
+            }
+        }
+    }
 }

contracts/zero-ex/contracts/src/features/UniswapV3Feature.sol

@@ -0,0 +1,447 @@
+// 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 "@0x/contracts-erc20/contracts/src/v06/IEtherTokenV06.sol";
+import "../vendor/IUniswapV3Pool.sol";
+import "../migrations/LibMigrate.sol";
+import "../fixins/FixinCommon.sol";
+import "../fixins/FixinTokenSpender.sol";
+import "./interfaces/IFeature.sol";
+import "./interfaces/IUniswapV3Feature.sol";
+
+
+/// @dev VIP uniswap fill functions.
+contract UniswapV3Feature is
+    IFeature,
+    IUniswapV3Feature,
+    FixinCommon,
+    FixinTokenSpender
+{
+    /// @dev Name of this feature.
+    string public constant override FEATURE_NAME = "UniswapV3Feature";
+    /// @dev Version of this feature.
+    uint256 public immutable override FEATURE_VERSION = _encodeVersion(1, 1, 0);
+    /// @dev WETH contract.
+    IEtherTokenV06 private immutable WETH;
+    /// @dev UniswapV3 Factory contract address prepended with '0xff' and left-aligned.
+    bytes32 private immutable UNI_FF_FACTORY_ADDRESS;
+    /// @dev UniswapV3 pool init code hash.
+    bytes32 private immutable UNI_POOL_INIT_CODE_HASH;
+    /// @dev Minimum size of an encoded swap path:
+    ///      sizeof(address(inputToken) | uint24(fee) | address(outputToken))
+    uint256 private constant SINGLE_HOP_PATH_SIZE = 20 + 3 + 20;
+    /// @dev How many bytes to skip ahead in an encoded path to start at the next hop:
+    ///      sizeof(address(inputToken) | uint24(fee))
+    uint256 private constant PATH_SKIP_HOP_SIZE = 20 + 3;
+    /// @dev The size of the swap callback data.
+    uint256 private constant SWAP_CALLBACK_DATA_SIZE = 128;
+    /// @dev Minimum tick price sqrt ratio.
+    uint160 internal constant MIN_PRICE_SQRT_RATIO = 4295128739;
+    /// @dev Minimum tick price sqrt ratio.
+    uint160 internal constant MAX_PRICE_SQRT_RATIO = 1461446703485210103287273052203988822378723970342;
+    /// @dev Mask of lower 20 bytes.
+    uint256 private constant ADDRESS_MASK = 0x00ffffffffffffffffffffffffffffffffffffffff;
+    /// @dev Mask of lower 3 bytes.
+    uint256 private constant UINT24_MASK = 0xffffff;
+
+    /// @dev Construct this contract.
+    /// @param weth The WETH contract.
+    /// @param uniFactory The UniswapV3 factory contract.
+    /// @param poolInitCodeHash The UniswapV3 pool init code hash.
+    constructor(
+        IEtherTokenV06 weth,
+        address uniFactory,
+        bytes32 poolInitCodeHash
+    ) public {
+        WETH = weth;
+        UNI_FF_FACTORY_ADDRESS = bytes32((uint256(0xff) << 248) | (uint256(uniFactory) << 88));
+        UNI_POOL_INIT_CODE_HASH = poolInitCodeHash;
+    }
+
+    /// @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.sellEthForTokenToUniswapV3.selector);
+        _registerFeatureFunction(this.sellTokenForEthToUniswapV3.selector);
+        _registerFeatureFunction(this.sellTokenForTokenToUniswapV3.selector);
+        _registerFeatureFunction(this._sellHeldTokenForTokenToUniswapV3.selector);
+        _registerFeatureFunction(this.uniswapV3SwapCallback.selector);
+        return LibMigrate.MIGRATE_SUCCESS;
+    }
+
+    /// @dev Sell attached ETH directly against uniswap v3.
+    /// @param encodedPath Uniswap-encoded path, where the first token is WETH.
+    /// @param recipient The recipient of the bought tokens. Can be zero for sender.
+    /// @param minBuyAmount Minimum amount of the last token in the path to buy.
+    /// @return buyAmount Amount of the last token in the path bought.
+    function sellEthForTokenToUniswapV3(
+        bytes memory encodedPath,
+        uint256 minBuyAmount,
+        address recipient
+    )
+        public
+        payable
+        override
+        returns (uint256 buyAmount)
+    {
+        // Wrap ETH.
+        WETH.deposit{ value: msg.value }();
+        return _swap(
+            encodedPath,
+            msg.value,
+            minBuyAmount,
+            address(this), // we are payer because we hold the WETH
+            _normalizeRecipient(recipient)
+        );
+    }
+
+    /// @dev Sell a token for ETH directly against uniswap v3.
+    /// @param encodedPath Uniswap-encoded path, where the last token is WETH.
+    /// @param sellAmount amount of the first token in the path to sell.
+    /// @param minBuyAmount Minimum amount of ETH to buy.
+    /// @param recipient The recipient of the bought tokens. Can be zero for sender.
+    /// @return buyAmount Amount of ETH bought.
+    function sellTokenForEthToUniswapV3(
+        bytes memory encodedPath,
+        uint256 sellAmount,
+        uint256 minBuyAmount,
+        address payable recipient
+    )
+        public
+        override
+        returns (uint256 buyAmount)
+    {
+        buyAmount = _swap(
+            encodedPath,
+            sellAmount,
+            minBuyAmount,
+            msg.sender,
+            address(this) // we are recipient because we need to unwrap WETH
+        );
+        WETH.withdraw(buyAmount);
+        // Transfer ETH to recipient.
+        (bool success, bytes memory revertData) =
+            _normalizeRecipient(recipient).call{ value: buyAmount }("");
+        if (!success) {
+            revertData.rrevert();
+        }
+    }
+
+    /// @dev Sell a token for another token directly against uniswap v3.
+    /// @param encodedPath Uniswap-encoded path.
+    /// @param sellAmount amount of the first token in the path to sell.
+    /// @param minBuyAmount Minimum amount of the last token in the path to buy.
+    /// @param recipient The recipient of the bought tokens. Can be zero for sender.
+    /// @return buyAmount Amount of the last token in the path bought.
+    function sellTokenForTokenToUniswapV3(
+        bytes memory encodedPath,
+        uint256 sellAmount,
+        uint256 minBuyAmount,
+        address recipient
+    )
+        public
+        override
+        returns (uint256 buyAmount)
+    {
+        buyAmount = _swap(
+            encodedPath,
+            sellAmount,
+            minBuyAmount,
+            msg.sender,
+            _normalizeRecipient(recipient)
+        );
+    }
+
+    /// @dev Sell a token for another token directly against uniswap v3.
+    ///      Private variant, uses tokens held by `address(this)`.
+    /// @param encodedPath Uniswap-encoded path.
+    /// @param sellAmount amount of the first token in the path to sell.
+    /// @param minBuyAmount Minimum amount of the last token in the path to buy.
+    /// @param recipient The recipient of the bought tokens. Can be zero for sender.
+    /// @return buyAmount Amount of the last token in the path bought.
+    function _sellHeldTokenForTokenToUniswapV3(
+        bytes memory encodedPath,
+        uint256 sellAmount,
+        uint256 minBuyAmount,
+        address recipient
+    )
+        public
+        override
+        onlySelf
+        returns (uint256 buyAmount)
+    {
+        buyAmount = _swap(
+            encodedPath,
+            sellAmount,
+            minBuyAmount,
+            address(this),
+            _normalizeRecipient(recipient)
+        );
+    }
+
+    /// @dev The UniswapV3 pool swap callback which pays the funds requested
+    ///      by the caller/pool to the pool. Can only be called by a valid
+    ///      UniswapV3 pool.
+    /// @param amount0Delta Token0 amount owed.
+    /// @param amount1Delta Token1 amount owed.
+    /// @param data Arbitrary data forwarded from swap() caller. An ABI-encoded
+    ///        struct of: inputToken, outputToken, fee, payer
+    function uniswapV3SwapCallback(
+        int256 amount0Delta,
+        int256 amount1Delta,
+        bytes calldata data
+    )
+        external
+        override
+    {
+        IERC20TokenV06 token0;
+        IERC20TokenV06 token1;
+        address payer;
+        {
+            uint24 fee;
+            // Decode the data.
+            require(data.length == SWAP_CALLBACK_DATA_SIZE, "UniswapFeature/INVALID_SWAP_CALLBACK_DATA");
+            assembly {
+                let p := add(36, calldataload(68))
+                token0 := calldataload(p)
+                token1 := calldataload(add(p, 32))
+                fee := calldataload(add(p, 64))
+                payer := calldataload(add(p, 96))
+            }
+            (token0, token1) = token0 < token1
+                ? (token0, token1)
+                : (token1, token0);
+            // Only a valid pool contract can call this function.
+            require(
+                msg.sender == address(_toPool(token0, fee, token1)),
+                "UniswapV3Feature/INVALID_SWAP_CALLBACK_CALLER"
+            );
+        }
+        // Pay the amount owed to the pool.
+        if (amount0Delta > 0) {
+            _pay(token0, payer, msg.sender, uint256(amount0Delta));
+        } else if (amount1Delta > 0) {
+            _pay(token1, payer, msg.sender, uint256(amount1Delta));
+        } else {
+            revert("UniswapV3Feature/INVALID_SWAP_AMOUNTS");
+        }
+    }
+
+    // Executes successive swaps along an encoded uniswap path.
+    function _swap(
+        bytes memory encodedPath,
+        uint256 sellAmount,
+        uint256 minBuyAmount,
+        address payer,
+        address recipient
+    )
+        private
+        returns (uint256 buyAmount)
+    {
+        if (sellAmount != 0) {
+            require(sellAmount <= uint256(type(int256).max), "UniswapV3Feature/SELL_AMOUNT_OVERFLOW");
+
+            // Perform a swap for each hop in the path.
+            bytes memory swapCallbackData = new bytes(SWAP_CALLBACK_DATA_SIZE);
+            while (true) {
+                bool isPathMultiHop = _isPathMultiHop(encodedPath);
+                bool zeroForOne;
+                IUniswapV3Pool pool;
+                {
+                    (
+                        IERC20TokenV06 inputToken,
+                        uint24 fee,
+                        IERC20TokenV06 outputToken
+                    ) = _decodeFirstPoolInfoFromPath(encodedPath);
+                    pool = _toPool(inputToken, fee, outputToken);
+                    zeroForOne = inputToken < outputToken;
+                    _updateSwapCallbackData(
+                        swapCallbackData,
+                        inputToken,
+                        outputToken,
+                        fee,
+                        payer
+                    );
+                }
+                (int256 amount0, int256 amount1) = pool.swap(
+                    // Intermediate tokens go to this contract.
+                    isPathMultiHop ? address(this) : recipient,
+                    zeroForOne,
+                    int256(sellAmount),
+                    zeroForOne
+                        ? MIN_PRICE_SQRT_RATIO + 1
+                        : MAX_PRICE_SQRT_RATIO - 1,
+                    swapCallbackData
+                );
+                {
+                    int256 _buyAmount = -(zeroForOne ? amount1 : amount0);
+                    require(_buyAmount >= 0, "UniswapV3Feature/INVALID_BUY_AMOUNT");
+                    buyAmount = uint256(_buyAmount);
+                }
+                if (!isPathMultiHop) {
+                    // Done.
+                    break;
+                }
+                // Continue with next hop.
+                payer = address(this); // Subsequent hops are paid for by us.
+                sellAmount = buyAmount;
+                // Skip to next hop along path.
+                encodedPath = _shiftHopFromPathInPlace(encodedPath);
+            }
+        }
+        require(minBuyAmount <= buyAmount, "UniswapV3Feature/UNDERBOUGHT");
+    }
+
+    // Pay tokens from `payer` to `to`, using `transferFrom()` if
+    // `payer` != this contract.
+    function _pay(
+        IERC20TokenV06 token,
+        address payer,
+        address to,
+        uint256 amount
+    )
+        private
+    {
+        if (payer != address(this)) {
+            _transferERC20TokensFrom(token, payer, to, amount);
+        } else {
+            _transferERC20Tokens(token, to, amount);
+        }
+    }
+
+    // Update `swapCallbackData` in place with new values.
+    function _updateSwapCallbackData(
+        bytes memory swapCallbackData,
+        IERC20TokenV06 inputToken,
+        IERC20TokenV06 outputToken,
+        uint24 fee,
+        address payer
+    )
+        private
+        pure
+    {
+        assembly {
+            let p := add(swapCallbackData, 32)
+            mstore(p, inputToken)
+            mstore(add(p, 32), outputToken)
+            mstore(add(p, 64), and(UINT24_MASK, fee))
+            mstore(add(p, 96), and(ADDRESS_MASK, payer))
+        }
+    }
+
+    // Compute the pool address given two tokens and a fee.
+    function _toPool(
+        IERC20TokenV06 inputToken,
+        uint24 fee,
+        IERC20TokenV06 outputToken
+    )
+        private
+        view
+        returns (IUniswapV3Pool pool)
+    {
+        // address(keccak256(abi.encodePacked(
+        //     hex"ff",
+        //     UNI_FACTORY_ADDRESS,
+        //     keccak256(abi.encode(inputToken, outputToken, fee)),
+        //     UNI_POOL_INIT_CODE_HASH
+        // )))
+        bytes32 ffFactoryAddress = UNI_FF_FACTORY_ADDRESS;
+        bytes32 poolInitCodeHash = UNI_POOL_INIT_CODE_HASH;
+        (IERC20TokenV06 token0, IERC20TokenV06 token1) = inputToken < outputToken
+            ? (inputToken, outputToken)
+            : (outputToken, inputToken);
+        assembly {
+            let s := mload(0x40)
+            let p := s
+            mstore(p, ffFactoryAddress)
+            p := add(p, 21)
+            // Compute the inner hash in-place
+                mstore(p, token0)
+                mstore(add(p, 32), token1)
+                mstore(add(p, 64), and(UINT24_MASK, fee))
+                mstore(p, keccak256(p, 96))
+            p := add(p, 32)
+            mstore(p, poolInitCodeHash)
+            pool := and(ADDRESS_MASK, keccak256(s, 85))
+        }
+    }
+
+    // Return whether or not an encoded uniswap path contains more than one hop.
+    function _isPathMultiHop(bytes memory encodedPath)
+        private
+        pure
+        returns (bool isMultiHop)
+    {
+        return encodedPath.length > SINGLE_HOP_PATH_SIZE;
+    }
+
+
+    // Return the first input token, output token, and fee of an encoded uniswap path.
+    function _decodeFirstPoolInfoFromPath(bytes memory encodedPath)
+        private
+        pure
+        returns (
+            IERC20TokenV06 inputToken,
+            uint24 fee,
+            IERC20TokenV06 outputToken
+        )
+    {
+        require(encodedPath.length >= SINGLE_HOP_PATH_SIZE, "UniswapV3Feature/BAD_PATH_ENCODING");
+        assembly {
+            let p := add(encodedPath, 32)
+            inputToken := shr(96, mload(p))
+            p := add(p, 20)
+            fee := shr(232, mload(p))
+            p := add(p, 3)
+            outputToken := shr(96, mload(p))
+        }
+    }
+
+    // Skip past the first hop of an encoded uniswap path in-place.
+    function _shiftHopFromPathInPlace(bytes memory encodedPath)
+        private
+        pure
+        returns (bytes memory shiftedEncodedPath)
+    {
+        require(encodedPath.length >= PATH_SKIP_HOP_SIZE, "UniswapV3Feature/BAD_PATH_ENCODING");
+        uint256 shiftSize = PATH_SKIP_HOP_SIZE;
+        uint256 newSize = encodedPath.length - shiftSize;
+        assembly {
+            shiftedEncodedPath := add(encodedPath, shiftSize)
+            mstore(shiftedEncodedPath, newSize)
+        }
+    }
+
+    // Convert null address values to msg.sender.
+    function _normalizeRecipient(address recipient)
+        private
+        view
+        returns (address payable normalizedRecipient)
+    {
+        return recipient == address(0) ? msg.sender : payable(recipient);
+    }
+}

contracts/zero-ex/contracts/src/features/interfaces/IMultiplexFeature.sol

@@ -24,9 +24,21 @@ import "@0x/contracts-erc20/contracts/src/v06/IERC20TokenV06.sol";
 
 
 interface IMultiplexFeature {
+    // Identifies the type of subcall.
+    enum MultiplexSubcall {
+        Invalid,
+        RFQ,
+        OTC,
+        UniswapV2,
+        UniswapV3,
+        LiquidityProvider,
+        TransformERC20,
+        BatchSell,
+        MultiHopSell
+    }
 
-    // Parameters for `batchFill`.
-    struct BatchFillData {
+    // Parameters for a batch sell.
+    struct BatchSellParams {
         // The token being sold.
         IERC20TokenV06 inputToken;
         // The token being bought.
@@ -34,84 +46,182 @@ interface IMultiplexFeature {
         // The amount of `inputToken` to sell.
         uint256 sellAmount;
         // The nested calls to perform.
-        WrappedBatchCall[] calls;
+        BatchSellSubcall[] calls;
+        // Whether to use the Exchange Proxy's balance
+        // of input tokens.
+        bool useSelfBalance;
+        // The recipient of the bought output tokens.
+        address recipient;
     }
 
-    // Represents a call nested within a `batchFill`.
-    struct WrappedBatchCall {
-        // The selector of the function to call.
-        bytes4 selector;
-        // Amount of `inputToken` to sell.
+    // Represents a constituent call of a batch sell.
+    struct BatchSellSubcall {
+        // The function to call.
+        MultiplexSubcall id;
+        // Amount of input token to sell. If the highest bit is 1,
+        // this value represents a proportion of the total
+        // `sellAmount` of the batch sell. See `_normalizeSellAmount`
+        // for details.
         uint256 sellAmount;
         // ABI-encoded parameters needed to perform the call.
         bytes data;
     }
 
-    // Parameters for `multiHopFill`.
-    struct MultiHopFillData {
+    // Parameters for a multi-hop sell.
+    struct MultiHopSellParams {
         // The sell path, i.e.
         // tokens = [inputToken, hopToken1, ..., hopTokenN, outputToken]
         address[] tokens;
         // The amount of `tokens[0]` to sell.
         uint256 sellAmount;
         // The nested calls to perform.
-        WrappedMultiHopCall[] calls;
+        MultiHopSellSubcall[] calls;
+        // Whether to use the Exchange Proxy's balance
+        // of input tokens.
+        bool useSelfBalance;
+        // The recipient of the bought output tokens.
+        address recipient;
     }
 
-    // Represents a call nested within a `multiHopFill`.
-    struct WrappedMultiHopCall {
-        // The selector of the function to call.
-        bytes4 selector;
+    // Represents a constituent call of a multi-hop sell.
+    struct MultiHopSellSubcall {
+        // The function to call.
+        MultiplexSubcall id;
         // ABI-encoded parameters needed to perform the call.
         bytes data;
     }
 
-    event LiquidityProviderSwap(
-        address inputToken,
-        address outputToken,
-        uint256 inputTokenAmount,
-        uint256 outputTokenAmount,
-        address provider,
-        address recipient
-    );
+    struct BatchSellState {
+        // Tracks the amount of input token sold.
+        uint256 soldAmount;
+        // Tracks the amount of output token bought.
+        uint256 boughtAmount;
+    }
 
-    event ExpiredRfqOrder(
-        bytes32 orderHash,
-        address maker,
-        uint64 expiry
-    );
+    struct MultiHopSellState {
+        // This variable is used for the input and output amounts of
+        // each hop. After the final hop, this will contain the output
+        // amount of the multi-hop sell.
+        uint256 outputTokenAmount;
+        // For each hop in a multi-hop sell, `from` is the
+        // address that holds the input tokens of the hop,
+        // `to` is the address that receives the output tokens
+        // of the hop.
+        // See `_computeHopTarget` for details.
+        address from;
+        address to;
+        // The index of the current hop in the multi-hop chain.
+        uint256 hopIndex;
+    }
 
-    /// @dev Executes a batch of fills selling `fillData.inputToken`
-    ///      for `fillData.outputToken` in sequence. Refer to the
-    ///      internal variant `_batchFill` for the allowed nested
-    ///      operations.
-    /// @param fillData Encodes the input/output tokens, the sell
-    ///        amount, and the nested operations for this batch fill.
-    /// @param minBuyAmount The minimum amount of `fillData.outputToken`
-    ///        to buy. Reverts if this amount is not met.
-    /// @return outputTokenAmount The amount of the output token bought.
-    function batchFill(
-        BatchFillData calldata fillData,
+    /// @dev Sells attached ETH for `outputToken` using the provided
+    ///      calls.
+    /// @param outputToken The token to buy.
+    /// @param calls The calls to use to sell the attached ETH.
+    /// @param minBuyAmount The minimum amount of `outputToken` that
+    ///        must be bought for this function to not revert.
+    /// @return boughtAmount The amount of `outputToken` bought.
+    function multiplexBatchSellEthForToken(
+        IERC20TokenV06 outputToken,
+        BatchSellSubcall[] calldata calls,
         uint256 minBuyAmount
     )
         external
         payable
-        returns (uint256 outputTokenAmount);
+        returns (uint256 boughtAmount);
 
-    /// @dev Executes a sequence of fills "hopping" through the
-    ///      path of tokens given by `fillData.tokens`. Refer to the
-    ///      internal variant `_multiHopFill` for the allowed nested
-    ///      operations.
-    /// @param fillData Encodes the path of tokens, the sell amount,
-    ///        and the nested operations for this multi-hop fill.
-    /// @param minBuyAmount The minimum amount of the output token
-    ///        to buy. Reverts if this amount is not met.
-    /// @return outputTokenAmount The amount of the output token bought.
-    function multiHopFill(
-        MultiHopFillData calldata fillData,
+    /// @dev Sells `sellAmount` of the given `inputToken` for ETH
+    ///      using the provided calls.
+    /// @param inputToken The token to sell.
+    /// @param calls The calls to use to sell the input tokens.
+    /// @param sellAmount The amount of `inputToken` to sell.
+    /// @param minBuyAmount The minimum amount of ETH that
+    ///        must be bought for this function to not revert.
+    /// @return boughtAmount The amount of ETH bought.
+    function multiplexBatchSellTokenForEth(
+        IERC20TokenV06 inputToken,
+        BatchSellSubcall[] calldata calls,
+        uint256 sellAmount,
+        uint256 minBuyAmount
+    )
+        external
+        returns (uint256 boughtAmount);
+
+    /// @dev Sells `sellAmount` of the given `inputToken` for
+    ///      `outputToken` using the provided calls.
+    /// @param inputToken The token to sell.
+    /// @param outputToken The token to buy.
+    /// @param calls The calls to use to sell the input tokens.
+    /// @param sellAmount The amount of `inputToken` to sell.
+    /// @param minBuyAmount The minimum amount of `outputToken`
+    ///        that must be bought for this function to not revert.
+    /// @return boughtAmount The amount of `outputToken` bought.
+    function multiplexBatchSellTokenForToken(
+        IERC20TokenV06 inputToken,
+        IERC20TokenV06 outputToken,
+        BatchSellSubcall[] calldata calls,
+        uint256 sellAmount,
+        uint256 minBuyAmount
+    )
+        external
+        returns (uint256 boughtAmount);
+
+    /// @dev Sells attached ETH via the given sequence of tokens
+    ///      and calls. `tokens[0]` must be WETH.
+    ///      The last token in `tokens` is the output token that
+    ///      will ultimately be sent to `msg.sender`
+    /// @param tokens The sequence of tokens to use for the sell,
+    ///        i.e. `tokens[i]` will be sold for `tokens[i+1]` via
+    ///        `calls[i]`.
+    /// @param calls The sequence of calls to use for the sell.
+    /// @param minBuyAmount The minimum amount of output tokens that
+    ///        must be bought for this function to not revert.
+    /// @return boughtAmount The amount of output tokens bought.
+    function multiplexMultiHopSellEthForToken(
+        address[] calldata tokens,
+        MultiHopSellSubcall[] calldata calls,
         uint256 minBuyAmount
     )
         external
         payable
-        returns (uint256 outputTokenAmount);
+        returns (uint256 boughtAmount);
+
+    /// @dev Sells `sellAmount` of the input token (`tokens[0]`)
+    ///      for ETH via the given sequence of tokens and calls.
+    ///      The last token in `tokens` must be WETH.
+    /// @param tokens The sequence of tokens to use for the sell,
+    ///        i.e. `tokens[i]` will be sold for `tokens[i+1]` via
+    ///        `calls[i]`.
+    /// @param calls The sequence of calls to use for the sell.
+    /// @param minBuyAmount The minimum amount of ETH that
+    ///        must be bought for this function to not revert.
+    /// @return boughtAmount The amount of ETH bought.
+    function multiplexMultiHopSellTokenForEth(
+        address[] calldata tokens,
+        MultiHopSellSubcall[] calldata calls,
+        uint256 sellAmount,
+        uint256 minBuyAmount
+    )
+        external
+        returns (uint256 boughtAmount);
+
+    /// @dev Sells `sellAmount` of the input token (`tokens[0]`)
+    ///      via the given sequence of tokens and calls.
+    ///      The last token in `tokens` is the output token that
+    ///      will ultimately be sent to `msg.sender`
+    /// @param tokens The sequence of tokens to use for the sell,
+    ///        i.e. `tokens[i]` will be sold for `tokens[i+1]` via
+    ///        `calls[i]`.
+    /// @param calls The sequence of calls to use for the sell.
+    /// @param minBuyAmount The minimum amount of output tokens that
+    ///        must be bought for this function to not revert.
+    /// @return boughtAmount The amount of output tokens bought.
+    function multiplexMultiHopSellTokenForToken(
+        address[] calldata tokens,
+        MultiHopSellSubcall[] calldata calls,
+        uint256 sellAmount,
+        uint256 minBuyAmount
+    )
+        external
+        returns (uint256 boughtAmount);
 }

contracts/zero-ex/contracts/src/features/interfaces/INativeOrdersFeature.sol

@@ -126,13 +126,18 @@ interface INativeOrdersFeature is
     /// @param signature The order signature.
     /// @param takerTokenFillAmount Maximum taker token to fill this order with.
     /// @param taker The order taker.
+    /// @param useSelfBalance Whether to use the ExchangeProxy's transient
+    ///        balance of taker tokens to fill the order.
+    /// @param recipient The recipient of the maker tokens.
     /// @return takerTokenFilledAmount How much maker token was filled.
     /// @return makerTokenFilledAmount How much maker token was filled.
     function _fillRfqOrder(
         LibNativeOrder.RfqOrder calldata order,
         LibSignature.Signature calldata signature,
         uint128 takerTokenFillAmount,
-        address taker
+        address taker,
+        bool useSelfBalance,
+        address recipient
     )
         external
         returns (uint128 takerTokenFilledAmount, uint128 makerTokenFilledAmount);

contracts/zero-ex/contracts/src/features/interfaces/IOtcOrdersFeature.sol

@@ -0,0 +1,184 @@
+// 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 "../libs/LibNativeOrder.sol";
+import "../libs/LibSignature.sol";
+
+
+/// @dev Feature for interacting with OTC orders.
+interface IOtcOrdersFeature {
+
+    /// @dev Emitted whenever an `OtcOrder` is filled.
+    /// @param orderHash The canonical hash of the order.
+    /// @param maker The maker of the order.
+    /// @param taker The taker of the order.
+    /// @param makerTokenFilledAmount How much maker token was filled.
+    /// @param takerTokenFilledAmount How much taker token was filled.
+    event OtcOrderFilled(
+        bytes32 orderHash,
+        address maker,
+        address taker,
+        address makerToken,
+        address takerToken,
+        uint128 makerTokenFilledAmount,
+        uint128 takerTokenFilledAmount
+    );
+
+    /// @dev Fill an OTC order for up to `takerTokenFillAmount` taker tokens.
+    /// @param order The OTC order.
+    /// @param makerSignature The order signature from the maker.
+    /// @param takerTokenFillAmount Maximum taker token amount to fill this
+    ///        order with.
+    /// @return takerTokenFilledAmount How much taker token was filled.
+    /// @return makerTokenFilledAmount How much maker token was filled.
+    function fillOtcOrder(
+        LibNativeOrder.OtcOrder calldata order,
+        LibSignature.Signature calldata makerSignature,
+        uint128 takerTokenFillAmount
+    )
+        external
+        returns (uint128 takerTokenFilledAmount, uint128 makerTokenFilledAmount);
+
+    /// @dev Fill an OTC order for up to `takerTokenFillAmount` taker tokens.
+    ///      Unwraps bought WETH into ETH before sending it to 
+    ///      the taker.
+    /// @param order The OTC order.
+    /// @param makerSignature The order signature from the maker.
+    /// @param takerTokenFillAmount Maximum taker token amount to fill this
+    ///        order with.
+    /// @return takerTokenFilledAmount How much taker token was filled.
+    /// @return makerTokenFilledAmount How much maker token was filled.
+    function fillOtcOrderForEth(
+        LibNativeOrder.OtcOrder calldata order,
+        LibSignature.Signature calldata makerSignature,
+        uint128 takerTokenFillAmount
+    )
+        external
+        returns (uint128 takerTokenFilledAmount, uint128 makerTokenFilledAmount);
+
+    /// @dev Fill an OTC order whose taker token is WETH for up
+    ///      to `msg.value`.
+    /// @param order The OTC order.
+    /// @param makerSignature The order signature from the maker.
+    /// @return takerTokenFilledAmount How much taker token was filled.
+    /// @return makerTokenFilledAmount How much maker token was filled.
+    function fillOtcOrderWithEth(
+        LibNativeOrder.OtcOrder calldata order,
+        LibSignature.Signature calldata makerSignature
+    )
+        external
+        payable
+        returns (uint128 takerTokenFilledAmount, uint128 makerTokenFilledAmount);
+
+    /// @dev Fully fill an OTC order. "Meta-transaction" variant,
+    ///      requires order to be signed by both maker and taker.
+    /// @param order The OTC order.
+    /// @param makerSignature The order signature from the maker.
+    /// @param takerSignature The order signature from the taker.
+    function fillTakerSignedOtcOrder(
+        LibNativeOrder.OtcOrder calldata order,
+        LibSignature.Signature calldata makerSignature,
+        LibSignature.Signature calldata takerSignature
+    )
+        external;
+
+    /// @dev Fully fill an OTC order. "Meta-transaction" variant,
+    ///      requires order to be signed by both maker and taker.
+    ///      Unwraps bought WETH into ETH before sending it to 
+    ///      the taker.
+    /// @param order The OTC order.
+    /// @param makerSignature The order signature from the maker.
+    /// @param takerSignature The order signature from the taker.
+    function fillTakerSignedOtcOrderForEth(
+        LibNativeOrder.OtcOrder calldata order,
+        LibSignature.Signature calldata makerSignature,
+        LibSignature.Signature calldata takerSignature
+    )
+        external;
+
+    /// @dev Fills multiple taker-signed OTC orders.
+    /// @param orders Array of OTC orders.
+    /// @param makerSignatures Array of maker signatures for each order.
+    /// @param takerSignatures Array of taker signatures for each order.
+    /// @param unwrapWeth Array of booleans representing whether or not 
+    ///        to unwrap bought WETH into ETH for each order. Should be set 
+    ///        to false if the maker token is not WETH.
+    /// @return successes Array of booleans representing whether or not
+    ///         each order in `orders` was filled successfully.
+    function batchFillTakerSignedOtcOrders(
+        LibNativeOrder.OtcOrder[] calldata orders,
+        LibSignature.Signature[] calldata makerSignatures,
+        LibSignature.Signature[] calldata takerSignatures,
+        bool[] calldata unwrapWeth
+    )
+        external
+        returns (bool[] memory successes);
+
+    /// @dev Fill an OTC order for up to `takerTokenFillAmount` taker tokens.
+    ///      Internal variant.
+    /// @param order The OTC order.
+    /// @param makerSignature The order signature from the maker.
+    /// @param takerTokenFillAmount Maximum taker token amount to fill this
+    ///        order with.
+    /// @param taker The address to fill the order in the context of.
+    /// @param useSelfBalance Whether to use the Exchange Proxy's balance
+    ///        of input tokens.
+    /// @param recipient The recipient of the bought maker tokens.
+    /// @return takerTokenFilledAmount How much taker token was filled.
+    /// @return makerTokenFilledAmount How much maker token was filled.
+    function _fillOtcOrder(
+        LibNativeOrder.OtcOrder calldata order,
+        LibSignature.Signature calldata makerSignature,
+        uint128 takerTokenFillAmount,
+        address taker,
+        bool useSelfBalance,
+        address recipient
+    )
+        external
+        returns (uint128 takerTokenFilledAmount, uint128 makerTokenFilledAmount);
+
+    /// @dev Get the order info for an OTC order.
+    /// @param order The OTC order.
+    /// @return orderInfo Info about the order.
+    function getOtcOrderInfo(LibNativeOrder.OtcOrder calldata order)
+        external
+        view
+        returns (LibNativeOrder.OtcOrderInfo memory orderInfo);
+
+    /// @dev Get the canonical hash of an OTC order.
+    /// @param order The OTC order.
+    /// @return orderHash The order hash.
+    function getOtcOrderHash(LibNativeOrder.OtcOrder calldata order)
+        external
+        view
+        returns (bytes32 orderHash);
+
+    /// @dev Get the last nonce used for a particular
+    ///      tx.origin address and nonce bucket.
+    /// @param txOrigin The address.
+    /// @param nonceBucket The nonce bucket index.
+    /// @return lastNonce The last nonce value used.
+    function lastOtcTxOriginNonce(address txOrigin, uint64 nonceBucket)
+        external
+        view
+        returns (uint128 lastNonce);
+}

contracts/zero-ex/contracts/src/features/interfaces/ITransformERC20Feature.sol

@@ -59,6 +59,10 @@ interface ITransformERC20Feature {
         // The transformations to execute on the token balance(s)
         // in sequence.
         Transformation[] transformations;
+        // Whether to use the Exchange Proxy's balance of `inputToken`.
+        bool useSelfBalance;
+        // The recipient of the bought `outputToken`.
+        address payable recipient;
     }
 
     /// @dev Raised upon a successful `transformERC20`.

contracts/zero-ex/contracts/src/features/interfaces/IUniswapV3Feature.sol

@@ -0,0 +1,102 @@
+// 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-erc20/contracts/src/v06/IERC20TokenV06.sol";
+
+
+/// @dev VIP uniswap v3 fill functions.
+interface IUniswapV3Feature {
+
+    /// @dev Sell attached ETH directly against uniswap v3.
+    /// @param encodedPath Uniswap-encoded path, where the first token is WETH.
+    /// @param minBuyAmount Minimum amount of the last token in the path to buy.
+    /// @param recipient The recipient of the bought tokens. Can be zero for sender.
+    /// @return buyAmount Amount of the last token in the path bought.
+    function sellEthForTokenToUniswapV3(
+        bytes memory encodedPath,
+        uint256 minBuyAmount,
+        address recipient
+    )
+        external
+        payable
+        returns (uint256 buyAmount);
+
+    /// @dev Sell a token for ETH directly against uniswap v3.
+    /// @param encodedPath Uniswap-encoded path, where the last token is WETH.
+    /// @param sellAmount amount of the first token in the path to sell.
+    /// @param minBuyAmount Minimum amount of ETH to buy.
+    /// @param recipient The recipient of the bought tokens. Can be zero for sender.
+    /// @return buyAmount Amount of ETH bought.
+    function sellTokenForEthToUniswapV3(
+        bytes memory encodedPath,
+        uint256 sellAmount,
+        uint256 minBuyAmount,
+        address payable recipient
+    )
+        external
+        returns (uint256 buyAmount);
+
+    /// @dev Sell a token for another token directly against uniswap v3.
+    /// @param encodedPath Uniswap-encoded path.
+    /// @param sellAmount amount of the first token in the path to sell.
+    /// @param minBuyAmount Minimum amount of the last token in the path to buy.
+    /// @param recipient The recipient of the bought tokens. Can be zero for sender.
+    /// @return buyAmount Amount of the last token in the path bought.
+    function sellTokenForTokenToUniswapV3(
+        bytes memory encodedPath,
+        uint256 sellAmount,
+        uint256 minBuyAmount,
+        address recipient
+    )
+        external
+        returns (uint256 buyAmount);
+
+    /// @dev Sell a token for another token directly against uniswap v3.
+    ///      Private variant, uses tokens held by `address(this)`.
+    /// @param encodedPath Uniswap-encoded path.
+    /// @param sellAmount amount of the first token in the path to sell.
+    /// @param minBuyAmount Minimum amount of the last token in the path to buy.
+    /// @param recipient The recipient of the bought tokens. Can be zero for sender.
+    /// @return buyAmount Amount of the last token in the path bought.
+    function _sellHeldTokenForTokenToUniswapV3(
+        bytes memory encodedPath,
+        uint256 sellAmount,
+        uint256 minBuyAmount,
+        address recipient
+    )
+        external
+        returns (uint256 buyAmount);
+
+    /// @dev The UniswapV3 pool swap callback which pays the funds requested
+    ///      by the caller/pool to the pool. Can only be called by a valid
+    ///      UniswapV3 pool.
+    /// @param amount0Delta Token0 amount owed.
+    /// @param amount1Delta Token1 amount owed.
+    /// @param data Arbitrary data forwarded from swap() caller. An ABI-encoded
+    ///        struct of: inputToken, outputToken, fee, payer
+    function uniswapV3SwapCallback(
+        int256 amount0Delta,
+        int256 amount1Delta,
+        bytes calldata data
+    )
+        external;
+}

contracts/zero-ex/contracts/src/features/libs/LibNativeOrder.sol

@@ -69,6 +69,18 @@ library LibNativeOrder {
         uint256 salt;
     }
 
+    /// @dev An OTC limit order.
+    struct OtcOrder {
+        IERC20TokenV06 makerToken;
+        IERC20TokenV06 takerToken;
+        uint128 makerAmount;
+        uint128 takerAmount;
+        address maker;
+        address taker;
+        address txOrigin;
+        uint256 expiryAndNonce; // [uint64 expiry, uint64 nonceBucket, uint128 nonce]
+    }
+
     /// @dev Info on a limit or RFQ order.
     struct OrderInfo {
         bytes32 orderHash;
@@ -76,6 +88,12 @@ library LibNativeOrder {
         uint128 takerTokenFilledAmount;
     }
 
+    /// @dev Info on an OTC order.
+    struct OtcOrderInfo {
+        bytes32 orderHash;
+        OrderStatus status;
+    }
+
     uint256 private constant UINT_128_MASK = (1 << 128) - 1;
     uint256 private constant UINT_64_MASK = (1 << 64) - 1;
     uint256 private constant ADDRESS_MASK = (1 << 160) - 1;
@@ -118,6 +136,22 @@ library LibNativeOrder {
     uint256 private constant _RFQ_ORDER_TYPEHASH =
         0xe593d3fdfa8b60e5e17a1b2204662ecbe15c23f2084b9ad5bae40359540a7da9;
 
+    // The type hash for OTC orders, which is:
+    // keccak256(abi.encodePacked(
+    //     "OtcOrder(",
+    //       "address makerToken,",
+    //       "address takerToken,",
+    //       "uint128 makerAmount,",
+    //       "uint128 takerAmount,",
+    //       "address maker,",
+    //       "address taker,",
+    //       "address txOrigin,",
+    //       "uint256 expiryAndNonce"
+    //     ")"
+    // ))
+    uint256 private constant _OTC_ORDER_TYPEHASH =
+        0x2f754524de756ae72459efbe1ec88c19a745639821de528ac3fb88f9e65e35c8;
+
     /// @dev Get the struct hash of a limit order.
     /// @param order The limit order.
     /// @return structHash The struct hash of the order.
@@ -222,6 +256,49 @@ library LibNativeOrder {
         }
     }
 
+    /// @dev Get the struct hash of an OTC order.
+    /// @param order The OTC order.
+    /// @return structHash The struct hash of the order.
+    function getOtcOrderStructHash(OtcOrder memory order)
+        internal
+        pure
+        returns (bytes32 structHash)
+    {
+        // The struct hash is:
+        // keccak256(abi.encode(
+        //   TYPE_HASH,
+        //   order.makerToken,
+        //   order.takerToken,
+        //   order.makerAmount,
+        //   order.takerAmount,
+        //   order.maker,
+        //   order.taker,
+        //   order.txOrigin,
+        //   order.expiryAndNonce,
+        // ))
+        assembly {
+            let mem := mload(0x40)
+            mstore(mem, _OTC_ORDER_TYPEHASH)
+            // order.makerToken;
+            mstore(add(mem, 0x20), and(ADDRESS_MASK, mload(order)))
+            // order.takerToken;
+            mstore(add(mem, 0x40), and(ADDRESS_MASK, mload(add(order, 0x20))))
+            // order.makerAmount;
+            mstore(add(mem, 0x60), and(UINT_128_MASK, mload(add(order, 0x40))))
+            // order.takerAmount;
+            mstore(add(mem, 0x80), and(UINT_128_MASK, mload(add(order, 0x60))))
+            // order.maker;
+            mstore(add(mem, 0xA0), and(ADDRESS_MASK, mload(add(order, 0x80))))
+            // order.taker;
+            mstore(add(mem, 0xC0), and(ADDRESS_MASK, mload(add(order, 0xA0))))
+            // order.txOrigin;
+            mstore(add(mem, 0xE0), and(ADDRESS_MASK, mload(add(order, 0xC0))))
+            // order.expiryAndNonce;
+            mstore(add(mem, 0x100), mload(add(order, 0xE0)))
+            structHash := keccak256(mem, 0x120)
+        }
+    }
+
     /// @dev Refund any leftover protocol fees in `msg.value` to `msg.sender`.
     /// @param ethProtocolFeePaid How much ETH was paid in protocol fees.
     function refundExcessProtocolFeeToSender(uint256 ethProtocolFeePaid)

contracts/zero-ex/contracts/src/features/multiplex/MultiplexFeature.sol

@@ -0,0 +1,742 @@
+// 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 "@0x/contracts-erc20/contracts/src/v06/IEtherTokenV06.sol";
+import "@0x/contracts-utils/contracts/src/v06/LibSafeMathV06.sol";
+import "../../external/ILiquidityProviderSandbox.sol";
+import "../../fixins/FixinCommon.sol";
+import "../../fixins/FixinEIP712.sol";
+import "../../migrations/LibMigrate.sol";
+import "../interfaces/IFeature.sol";
+import "../interfaces/IMultiplexFeature.sol";
+import "./MultiplexLiquidityProvider.sol";
+import "./MultiplexOtc.sol";
+import "./MultiplexRfq.sol";
+import "./MultiplexTransformERC20.sol";
+import "./MultiplexUniswapV2.sol";
+import "./MultiplexUniswapV3.sol";
+
+
+/// @dev This feature enables efficient batch and multi-hop trades
+///      using different liquidity sources.
+contract MultiplexFeature is
+    IFeature,
+    IMultiplexFeature,
+    FixinCommon,
+    MultiplexLiquidityProvider,
+    MultiplexOtc,
+    MultiplexRfq,
+    MultiplexTransformERC20,
+    MultiplexUniswapV2,
+    MultiplexUniswapV3
+{
+    /// @dev Name of this feature.
+    string public constant override FEATURE_NAME = "MultiplexFeature";
+    /// @dev Version of this feature.
+    uint256 public immutable override FEATURE_VERSION = _encodeVersion(2, 0, 0);
+    /// @dev The highest bit of a uint256 value.
+    uint256 private constant HIGH_BIT = 2 ** 255;
+    /// @dev Mask of the lower 255 bits of a uint256 value.
+    uint256 private constant LOWER_255_BITS = HIGH_BIT - 1;
+
+    /// @dev The WETH token contract.
+    IEtherTokenV06 private immutable WETH;
+
+    constructor(
+        address zeroExAddress,
+        IEtherTokenV06 weth,
+        ILiquidityProviderSandbox sandbox,
+        address uniswapFactory,
+        address sushiswapFactory,
+        bytes32 uniswapPairInitCodeHash,
+        bytes32 sushiswapPairInitCodeHash
+    )
+        public
+        FixinEIP712(zeroExAddress)
+        MultiplexLiquidityProvider(sandbox)
+        MultiplexUniswapV2(
+            uniswapFactory,
+            sushiswapFactory,
+            uniswapPairInitCodeHash,
+            sushiswapPairInitCodeHash
+        )
+    {
+        WETH = 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.multiplexBatchSellEthForToken.selector);
+        _registerFeatureFunction(this.multiplexBatchSellTokenForEth.selector);
+        _registerFeatureFunction(this.multiplexBatchSellTokenForToken.selector);
+        _registerFeatureFunction(this.multiplexMultiHopSellEthForToken.selector);
+        _registerFeatureFunction(this.multiplexMultiHopSellTokenForEth.selector);
+        _registerFeatureFunction(this.multiplexMultiHopSellTokenForToken.selector);
+        return LibMigrate.MIGRATE_SUCCESS;
+    }
+
+    /// @dev Sells attached ETH for `outputToken` using the provided
+    ///      calls.
+    /// @param outputToken The token to buy.
+    /// @param calls The calls to use to sell the attached ETH.
+    /// @param minBuyAmount The minimum amount of `outputToken` that
+    ///        must be bought for this function to not revert.
+    /// @return boughtAmount The amount of `outputToken` bought.
+    function multiplexBatchSellEthForToken(
+        IERC20TokenV06 outputToken,
+        BatchSellSubcall[] memory calls,
+        uint256 minBuyAmount
+    )
+        public
+        override
+        payable
+        returns (uint256 boughtAmount)
+    {
+        // Wrap ETH.
+        WETH.deposit{value: msg.value}();
+        // WETH is now held by this contract,
+        // so `useSelfBalance` is true.
+        return _multiplexBatchSell(
+            BatchSellParams({
+                inputToken: WETH,
+                outputToken: outputToken,
+                sellAmount: msg.value,
+                calls: calls,
+                useSelfBalance: true,
+                recipient: msg.sender
+            }),
+            minBuyAmount
+        );
+    }
+
+    /// @dev Sells `sellAmount` of the given `inputToken` for ETH
+    ///      using the provided calls.
+    /// @param inputToken The token to sell.
+    /// @param calls The calls to use to sell the input tokens.
+    /// @param sellAmount The amount of `inputToken` to sell.
+    /// @param minBuyAmount The minimum amount of ETH that
+    ///        must be bought for this function to not revert.
+    /// @return boughtAmount The amount of ETH bought.
+    function multiplexBatchSellTokenForEth(
+        IERC20TokenV06 inputToken,
+        BatchSellSubcall[] memory calls,
+        uint256 sellAmount,
+        uint256 minBuyAmount
+    )
+        public
+        override
+        returns (uint256 boughtAmount)
+    {
+        // The outputToken is implicitly WETH. The `recipient`
+        // of the WETH is set to  this contract, since we
+        // must unwrap the WETH and transfer the resulting ETH.
+        boughtAmount = _multiplexBatchSell(
+            BatchSellParams({
+                inputToken: inputToken,
+                outputToken: WETH,
+                sellAmount: sellAmount,
+                calls: calls,
+                useSelfBalance: false,
+                recipient: address(this)
+            }),
+            minBuyAmount
+        );
+        // Unwrap WETH.
+        WETH.withdraw(boughtAmount);
+        // Transfer ETH to `msg.sender`.
+        _transferEth(msg.sender, boughtAmount);
+    }
+
+    /// @dev Sells `sellAmount` of the given `inputToken` for
+    ///      `outputToken` using the provided calls.
+    /// @param inputToken The token to sell.
+    /// @param outputToken The token to buy.
+    /// @param calls The calls to use to sell the input tokens.
+    /// @param sellAmount The amount of `inputToken` to sell.
+    /// @param minBuyAmount The minimum amount of `outputToken`
+    ///        that must be bought for this function to not revert.
+    /// @return boughtAmount The amount of `outputToken` bought.
+    function multiplexBatchSellTokenForToken(
+        IERC20TokenV06 inputToken,
+        IERC20TokenV06 outputToken,
+        BatchSellSubcall[] memory calls,
+        uint256 sellAmount,
+        uint256 minBuyAmount
+    )
+        public
+        override
+        returns (uint256 boughtAmount)
+    {
+        return _multiplexBatchSell(
+            BatchSellParams({
+                inputToken: inputToken,
+                outputToken: outputToken,
+                sellAmount: sellAmount,
+                calls: calls,
+                useSelfBalance: false,
+                recipient: msg.sender
+            }),
+            minBuyAmount
+        );
+    }
+
+    /// @dev Executes a batch sell and checks that at least
+    ///      `minBuyAmount` of `outputToken` was bought.
+    /// @param params Batch sell parameters.
+    /// @param minBuyAmount The minimum amount of `outputToken` that
+    ///        must be bought for this function to not revert.
+    /// @return boughtAmount The amount of `outputToken` bought.
+    function _multiplexBatchSell(
+        BatchSellParams memory params,
+        uint256 minBuyAmount
+    )
+        private
+        returns (uint256 boughtAmount)
+    {
+        // Cache the recipient's initial balance of the output token.
+        uint256 balanceBefore = params.outputToken.balanceOf(params.recipient);
+        // Execute the batch sell.
+        BatchSellState memory state = _executeBatchSell(params);
+        // Compute the change in balance of the output token.
+        uint256 balanceDelta = params.outputToken.balanceOf(params.recipient)
+            .safeSub(balanceBefore);
+        // Use the minimum of the balanceDelta and the returned bought
+        // amount in case of weird tokens and whatnot.
+        boughtAmount = LibSafeMathV06.min256(balanceDelta, state.boughtAmount);
+        // Enforce `minBuyAmount`.
+        require(
+            boughtAmount >= minBuyAmount,
+            "MultiplexFeature::_multiplexBatchSell/UNDERBOUGHT"
+        );
+    }
+
+    /// @dev Sells attached ETH via the given sequence of tokens
+    ///      and calls. `tokens[0]` must be WETH.
+    ///      The last token in `tokens` is the output token that
+    ///      will ultimately be sent to `msg.sender`
+    /// @param tokens The sequence of tokens to use for the sell,
+    ///        i.e. `tokens[i]` will be sold for `tokens[i+1]` via
+    ///        `calls[i]`.
+    /// @param calls The sequence of calls to use for the sell.
+    /// @param minBuyAmount The minimum amount of output tokens that
+    ///        must be bought for this function to not revert.
+    /// @return boughtAmount The amount of output tokens bought.
+    function multiplexMultiHopSellEthForToken(
+        address[] memory tokens,
+        MultiHopSellSubcall[] memory calls,
+        uint256 minBuyAmount
+    )
+        public
+        override
+        payable
+        returns (uint256 boughtAmount)
+    {
+        // First token must be WETH.
+        require(
+            tokens[0] == address(WETH),
+            "MultiplexFeature::multiplexMultiHopSellEthForToken/NOT_WETH"
+        );
+        // Wrap ETH.
+        WETH.deposit{value: msg.value}();
+        // WETH is now held by this contract,
+        // so `useSelfBalance` is true.
+        return _multiplexMultiHopSell(
+            MultiHopSellParams({
+                tokens: tokens,
+                sellAmount: msg.value,
+                calls: calls,
+                useSelfBalance: true,
+                recipient: msg.sender
+            }),
+            minBuyAmount
+        );
+    }
+
+    /// @dev Sells `sellAmount` of the input token (`tokens[0]`)
+    ///      for ETH via the given sequence of tokens and calls.
+    ///      The last token in `tokens` must be WETH.
+    /// @param tokens The sequence of tokens to use for the sell,
+    ///        i.e. `tokens[i]` will be sold for `tokens[i+1]` via
+    ///        `calls[i]`.
+    /// @param calls The sequence of calls to use for the sell.
+    /// @param sellAmount The amount of `inputToken` to sell.
+    /// @param minBuyAmount The minimum amount of ETH that
+    ///        must be bought for this function to not revert.
+    /// @return boughtAmount The amount of ETH bought.
+    function multiplexMultiHopSellTokenForEth(
+        address[] memory tokens,
+        MultiHopSellSubcall[] memory calls,
+        uint256 sellAmount,
+        uint256 minBuyAmount
+    )
+        public
+        override
+        returns (uint256 boughtAmount)
+    {
+        // Last token must be WETH.
+        require(
+            tokens[tokens.length - 1] == address(WETH),
+            "MultiplexFeature::multiplexMultiHopSellTokenForEth/NOT_WETH"
+        );
+        // The `recipient of the WETH is set to  this contract, since
+        // we must unwrap the WETH and transfer the resulting ETH.
+        boughtAmount = _multiplexMultiHopSell(
+            MultiHopSellParams({
+                tokens: tokens,
+                sellAmount: sellAmount,
+                calls: calls,
+                useSelfBalance: false,
+                recipient: address(this)
+            }),
+            minBuyAmount
+        );
+        // Unwrap WETH.
+        WETH.withdraw(boughtAmount);
+        // Transfer ETH to `msg.sender`.
+        _transferEth(msg.sender, boughtAmount);
+    }
+
+    /// @dev Sells `sellAmount` of the input token (`tokens[0]`)
+    ///      via the given sequence of tokens and calls.
+    ///      The last token in `tokens` is the output token that
+    ///      will ultimately be sent to `msg.sender`
+    /// @param tokens The sequence of tokens to use for the sell,
+    ///        i.e. `tokens[i]` will be sold for `tokens[i+1]` via
+    ///        `calls[i]`.
+    /// @param calls The sequence of calls to use for the sell.
+    /// @param sellAmount The amount of `inputToken` to sell.
+    /// @param minBuyAmount The minimum amount of output tokens that
+    ///        must be bought for this function to not revert.
+    /// @return boughtAmount The amount of output tokens bought.
+    function multiplexMultiHopSellTokenForToken(
+        address[] memory tokens,
+        MultiHopSellSubcall[] memory calls,
+        uint256 sellAmount,
+        uint256 minBuyAmount
+    )
+        public
+        override
+        returns (uint256 boughtAmount)
+    {
+        return _multiplexMultiHopSell(
+            MultiHopSellParams({
+                tokens: tokens,
+                sellAmount: sellAmount,
+                calls: calls,
+                useSelfBalance: false,
+                recipient: msg.sender
+            }),
+            minBuyAmount
+        );
+    }
+
+    /// @dev Executes a multi-hop sell and checks that at least
+    ///      `minBuyAmount` of output tokens were bought.
+    /// @param params Multi-hop sell parameters.
+    /// @param minBuyAmount The minimum amount of output tokens that
+    ///        must be bought for this function to not revert.
+    /// @return boughtAmount The amount of output tokens bought.
+    function _multiplexMultiHopSell(
+        MultiHopSellParams memory params,
+        uint256 minBuyAmount
+    )
+        private
+        returns (uint256 boughtAmount)
+    {
+        // There should be one call/hop between every two tokens
+        // in the path.
+        // tokens[0]––calls[0]––>tokens[1]––...––calls[n-1]––>tokens[n]
+        require(
+            params.tokens.length == params.calls.length + 1,
+            "MultiplexFeature::_multiplexMultiHopSell/MISMATCHED_ARRAY_LENGTHS"
+        );
+        // The output token is the last token in the path.
+        IERC20TokenV06 outputToken = IERC20TokenV06(
+            params.tokens[params.tokens.length - 1]
+        );
+        // Cache the recipient's balance of the output token.
+        uint256 balanceBefore = outputToken.balanceOf(params.recipient);
+        // Execute the multi-hop sell.
+        MultiHopSellState memory state = _executeMultiHopSell(params);
+        // Compute the change in balance of the output token.
+        uint256 balanceDelta = outputToken.balanceOf(params.recipient)
+            .safeSub(balanceBefore);
+        // Use the minimum of the balanceDelta and the returned bought
+        // amount in case of weird tokens and whatnot.
+        boughtAmount = LibSafeMathV06.min256(balanceDelta, state.outputTokenAmount);
+        // Enforce `minBuyAmount`.
+        require(
+            boughtAmount >= minBuyAmount,
+            "MultiplexFeature::_multiplexMultiHopSell/UNDERBOUGHT"
+        );
+    }
+
+    /// @dev Iterates through the constituent calls of a batch
+    ///      sell and executes each one, until the full amount
+    //       has been sold.
+    /// @param params Batch sell parameters.
+    /// @return state A struct containing the amounts of `inputToken`
+    ///         sold and `outputToken` bought.
+    function _executeBatchSell(BatchSellParams memory params)
+        private
+        returns (BatchSellState memory state)
+    {
+        // Iterate through the calls and execute each one
+        // until the full amount has been sold.
+        for (uint256 i = 0; i != params.calls.length; i++) {
+            // Check if we've hit our target.
+            if (state.soldAmount >= params.sellAmount) { break; }
+            BatchSellSubcall memory subcall = params.calls[i];
+            // Compute the input token amount.
+            uint256 inputTokenAmount = _normalizeSellAmount(
+                subcall.sellAmount,
+                params.sellAmount,
+                state.soldAmount
+            );
+            if (subcall.id == MultiplexSubcall.RFQ) {
+                _batchSellRfqOrder(
+                    state,
+                    params,
+                    subcall.data,
+                    inputTokenAmount
+                );
+            } else if (subcall.id == MultiplexSubcall.OTC) {
+                _batchSellOtcOrder(
+                    state,
+                    params,
+                    subcall.data,
+                    inputTokenAmount
+                );
+            } else if (subcall.id == MultiplexSubcall.UniswapV2) {
+                _batchSellUniswapV2(
+                    state,
+                    params,
+                    subcall.data,
+                    inputTokenAmount
+                );
+            } else if (subcall.id == MultiplexSubcall.UniswapV3) {
+                _batchSellUniswapV3(
+                    state,
+                    params,
+                    subcall.data,
+                    inputTokenAmount
+                );
+            } else if (subcall.id == MultiplexSubcall.LiquidityProvider) {
+                _batchSellLiquidityProvider(
+                    state,
+                    params,
+                    subcall.data,
+                    inputTokenAmount
+                );
+            } else if (subcall.id == MultiplexSubcall.TransformERC20) {
+                _batchSellTransformERC20(
+                    state,
+                    params,
+                    subcall.data,
+                    inputTokenAmount
+                );
+            } else if (subcall.id == MultiplexSubcall.MultiHopSell) {
+                _nestedMultiHopSell(
+                    state,
+                    params,
+                    subcall.data,
+                    inputTokenAmount
+                );
+            } else {
+                revert("MultiplexFeature::_executeBatchSell/INVALID_SUBCALL");
+            }
+        }
+        require(
+            state.soldAmount == params.sellAmount,
+            "MultiplexFeature::_executeBatchSell/INCORRECT_AMOUNT_SOLD"
+        );
+    }
+
+    // This function executes a sequence of fills "hopping" through the
+    // path of tokens given by `params.tokens`.
+    function _executeMultiHopSell(MultiHopSellParams memory params)
+        private
+        returns (MultiHopSellState memory state)
+    {
+        // This variable is used for the input and output amounts of
+        // each hop. After the final hop, this will contain the output
+        // amount of the multi-hop fill.
+        state.outputTokenAmount = params.sellAmount;
+        // The first call may expect the input tokens to be held by
+        // `msg.sender`, `address(this)`, or some other address.
+        // Compute the expected address and transfer the input tokens
+        // there if necessary.
+        state.from = _computeHopTarget(params, 0);
+        // If the input tokens are currently held by `msg.sender` but
+        // the first hop expects them elsewhere, perform a `transferFrom`.
+        if (!params.useSelfBalance && state.from != msg.sender) {
+            _transferERC20TokensFrom(
+                IERC20TokenV06(params.tokens[0]),
+                msg.sender,
+                state.from,
+                params.sellAmount
+            );
+        }
+        // If the input tokens are currently held by `address(this)` but
+        // the first hop expects them elsewhere, perform a `transfer`.
+        if (params.useSelfBalance && state.from != address(this)) {
+            _transferERC20Tokens(
+                IERC20TokenV06(params.tokens[0]),
+                state.from,
+                params.sellAmount
+            );
+        }
+        // Iterate through the calls and execute each one.
+        for (state.hopIndex = 0; state.hopIndex != params.calls.length; state.hopIndex++) {
+            MultiHopSellSubcall memory subcall = params.calls[state.hopIndex];
+            // Compute the recipient of the tokens that will be
+            // bought by the current hop.
+            state.to = _computeHopTarget(params, state.hopIndex + 1);
+
+            if (subcall.id == MultiplexSubcall.UniswapV2) {
+                _multiHopSellUniswapV2(
+                    state,
+                    params,
+                    subcall.data
+                );
+            } else if (subcall.id == MultiplexSubcall.UniswapV3) {
+                _multiHopSellUniswapV3(state, subcall.data);
+            } else if (subcall.id == MultiplexSubcall.LiquidityProvider) {
+                _multiHopSellLiquidityProvider(
+                    state,
+                    params,
+                    subcall.data
+                );
+            } else if (subcall.id == MultiplexSubcall.BatchSell) {
+                _nestedBatchSell(
+                    state,
+                    params,
+                    subcall.data
+                );
+            } else {
+                revert("MultiplexFeature::_executeMultiHopSell/INVALID_SUBCALL");
+            }
+            // The recipient of the current hop will be the source
+            // of tokens for the next hop.
+            state.from = state.to;
+        }
+    }
+
+    function _nestedMultiHopSell(
+        IMultiplexFeature.BatchSellState memory state,
+        IMultiplexFeature.BatchSellParams memory params,
+        bytes memory data,
+        uint256 sellAmount
+    )
+        private
+    {
+        MultiHopSellParams memory multiHopParams;
+        // Decode the tokens and calls for the nested
+        // multi-hop sell.
+        (
+            multiHopParams.tokens,
+            multiHopParams.calls
+        ) = abi.decode(
+            data,
+            (address[], MultiHopSellSubcall[])
+        );
+        multiHopParams.sellAmount = sellAmount;
+        // If the batch sell is using input tokens held by
+        // `address(this)`, then so should the nested
+        // multi-hop sell.
+        multiHopParams.useSelfBalance = params.useSelfBalance;
+        // Likewise, the recipient of the multi-hop sell is
+        // equal to the recipient of its containing batch sell.
+        multiHopParams.recipient = params.recipient;
+        // Execute the nested multi-hop sell.
+        uint256 outputTokenAmount =
+            _executeMultiHopSell(multiHopParams).outputTokenAmount;
+        // Increment the sold and bought amounts.
+        state.soldAmount = state.soldAmount.safeAdd(sellAmount);
+        state.boughtAmount = state.boughtAmount.safeAdd(outputTokenAmount);
+    }
+
+    function _nestedBatchSell(
+        IMultiplexFeature.MultiHopSellState memory state,
+        IMultiplexFeature.MultiHopSellParams memory params,
+        bytes memory data
+    )
+        private
+    {
+        BatchSellParams memory batchSellParams;
+        // Decode the calls for the nested batch sell.
+        batchSellParams.calls = abi.decode(
+            data,
+            (BatchSellSubcall[])
+        );
+        // The input and output tokens of the batch
+        // sell are the current and next tokens in
+        // `params.tokens`, respectively.
+        batchSellParams.inputToken = IERC20TokenV06(
+            params.tokens[state.hopIndex]
+        );
+        batchSellParams.outputToken = IERC20TokenV06(
+            params.tokens[state.hopIndex + 1]
+        );
+        // The `sellAmount` for the batch sell is the
+        // `outputTokenAmount` from the previous hop.
+        batchSellParams.sellAmount = state.outputTokenAmount;
+        // If the nested batch sell is the first hop
+        // and `useSelfBalance` for the containing multi-
+        // hop sell is false, the nested batch sell should
+        // pull tokens from `msg.sender` (so  `batchSellParams.useSelfBalance`
+        // should be false). Otherwise `batchSellParams.useSelfBalance`
+        // should be true.
+        batchSellParams.useSelfBalance = state.hopIndex > 0 || params.useSelfBalance;
+        // `state.to` has been populated with the address
+        // that should receive the output tokens of the
+        // batch sell.
+        batchSellParams.recipient = state.to;
+        // Execute the nested batch sell.
+        state.outputTokenAmount =
+            _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
+    // tokens prior to executing `calls[0]`. Otherwise, it is the address
+    // that should receive `tokens[i]` upon executing `calls[i-1]`.
+    function _computeHopTarget(
+        MultiHopSellParams memory params,
+        uint256 i
+    )
+        private
+        view
+        returns (address target)
+    {
+        if (i == params.calls.length) {
+            // The last call should send the output tokens to the
+            // multi-hop sell recipient.
+            target = params.recipient;
+        } else {
+            MultiHopSellSubcall memory subcall = params.calls[i];
+            if (subcall.id == MultiplexSubcall.UniswapV2) {
+                // UniswapV2 (and Sushiswap) allow tokens to be
+                // transferred into the pair contract before `swap`
+                // is called, so we compute the pair contract's address.
+                (address[] memory tokens, bool isSushi) = abi.decode(
+                    subcall.data,
+                    (address[], bool)
+                );
+                target = _computeUniswapPairAddress(
+                    tokens[0],
+                    tokens[1],
+                    isSushi
+                );
+            } else if (subcall.id == MultiplexSubcall.LiquidityProvider) {
+                // Similar to UniswapV2, LiquidityProvider contracts
+                // allow tokens to be transferred in before the swap
+                // is executed, so we the target is the address encoded
+                // in the subcall data.
+                (target,) = abi.decode(
+                    subcall.data,
+                    (address, bytes)
+                );
+            } else if (
+                subcall.id == MultiplexSubcall.UniswapV3 ||
+                subcall.id == MultiplexSubcall.BatchSell
+            ) {
+                // UniswapV3 uses a callback to pull in the tokens being
+                // sold to it. The callback implemented in `UniswapV3Feature`
+                // can either:
+                // - call `transferFrom` to move tokens from `msg.sender` to the
+                //   UniswapV3 pool, or
+                // - call `transfer` to move tokens from `address(this)` to the
+                //   UniswapV3 pool.
+                // A nested batch sell is similar, in that it can either:
+                // - use tokens from `msg.sender`, or
+                // - use tokens held by `address(this)`.
+
+                // Suppose UniswapV3/BatchSell is the first call in the multi-hop
+                // path. The input tokens are either held by `msg.sender`,
+                // or in the case of `multiplexMultiHopSellEthForToken` WETH is
+                // held by `address(this)`. The target is set accordingly.
+
+                // If this is _not_ the first call in the multi-hop path, we
+                // are dealing with an "intermediate" token in the multi-hop path,
+                // which `msg.sender` may not have an allowance set for. Thus
+                // target must be set to `address(this)` for `i > 0`.
+                if (i == 0 && !params.useSelfBalance) {
+                    target = msg.sender;
+                } else {
+                    target = address(this);
+                }
+            } else {
+                revert("MultiplexFeature::_computeHopTarget/INVALID_SUBCALL");
+            }
+        }
+        require(
+            target != address(0),
+            "MultiplexFeature::_computeHopTarget/TARGET_IS_NULL"
+        );
+    }
+
+    // If `rawAmount` encodes a proportion of `totalSellAmount`, this function
+    // converts it to an absolute quantity. Caps the normalized amount to
+    // the remaining sell amount (`totalSellAmount - soldAmount`).
+    function _normalizeSellAmount(
+        uint256 rawAmount,
+        uint256 totalSellAmount,
+        uint256 soldAmount
+    )
+        private
+        pure
+        returns (uint256 normalized)
+    {
+        if ((rawAmount & HIGH_BIT) == HIGH_BIT) {
+            // If the high bit of `rawAmount` is set then the lower 255 bits
+            // specify a fraction of `totalSellAmount`.
+            return LibSafeMathV06.min256(
+                totalSellAmount
+                    * LibSafeMathV06.min256(rawAmount & LOWER_255_BITS, 1e18)
+                    / 1e18,
+                totalSellAmount.safeSub(soldAmount)
+            );
+        } else {
+            return LibSafeMathV06.min256(
+                rawAmount,
+                totalSellAmount.safeSub(soldAmount)
+            );
+        }
+    }
+}

contracts/zero-ex/contracts/src/features/multiplex/MultiplexLiquidityProvider.sol

@@ -0,0 +1,202 @@
+// 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 "@0x/contracts-erc20/contracts/src/v06/LibERC20TokenV06.sol";
+import "@0x/contracts-utils/contracts/src/v06/LibSafeMathV06.sol";
+import "../../external/ILiquidityProviderSandbox.sol";
+import "../../fixins/FixinCommon.sol";
+import "../../fixins/FixinTokenSpender.sol";
+import "../../vendor/ILiquidityProvider.sol";
+import "../interfaces/IMultiplexFeature.sol";
+
+
+abstract contract MultiplexLiquidityProvider is
+    FixinCommon,
+    FixinTokenSpender
+{
+    using LibERC20TokenV06 for IERC20TokenV06;
+    using LibSafeMathV06 for uint256;
+
+    // Same event fired by LiquidityProviderFeature
+    event LiquidityProviderSwap(
+        address inputToken,
+        address outputToken,
+        uint256 inputTokenAmount,
+        uint256 outputTokenAmount,
+        address provider,
+        address recipient
+    );
+
+    /// @dev The sandbox contract address.
+    ILiquidityProviderSandbox private immutable SANDBOX;
+
+    constructor(ILiquidityProviderSandbox sandbox)
+        internal
+    {
+        SANDBOX = sandbox;
+    }
+
+    // A payable external function that we can delegatecall to
+    // swallow reverts and roll back the input token transfer.
+    function _batchSellLiquidityProviderExternal(
+        IMultiplexFeature.BatchSellParams calldata params,
+        bytes calldata wrappedCallData,
+        uint256 sellAmount
+    )
+        external
+        payable
+        returns (uint256 boughtAmount)
+    {
+        // Revert if not a delegatecall.
+        require(
+            address(this) != _implementation,
+            "MultiplexLiquidityProvider::_batchSellLiquidityProviderExternal/ONLY_DELEGATECALL"
+        );
+
+        // Decode the provider address and auxiliary data.
+        (address provider, bytes memory auxiliaryData) = abi.decode(
+            wrappedCallData,
+            (address, bytes)
+        );
+
+        if (params.useSelfBalance) {
+            // If `useSelfBalance` is true, use the input tokens
+            // held by `address(this)`.
+            _transferERC20Tokens(
+                params.inputToken,
+                provider,
+                sellAmount
+            );
+        } else {
+            // Otherwise, transfer the input tokens from `msg.sender`.
+            _transferERC20TokensFrom(
+                params.inputToken,
+                msg.sender,
+                provider,
+                sellAmount
+            );
+        }
+        // Cache the recipient's balance of the output token.
+        uint256 balanceBefore = params.outputToken
+            .balanceOf(params.recipient);
+        // Execute the swap.
+        SANDBOX.executeSellTokenForToken(
+            ILiquidityProvider(provider),
+            params.inputToken,
+            params.outputToken,
+            params.recipient,
+            0,
+            auxiliaryData
+        );
+        // Compute amount of output token received by the
+        // recipient.
+        boughtAmount = params.outputToken
+            .balanceOf(params.recipient)
+            .safeSub(balanceBefore);
+
+        emit LiquidityProviderSwap(
+            address(params.inputToken),
+            address(params.outputToken),
+            sellAmount,
+            boughtAmount,
+            provider,
+            params.recipient
+        );
+    }
+
+    function _batchSellLiquidityProvider(
+        IMultiplexFeature.BatchSellState memory state,
+        IMultiplexFeature.BatchSellParams memory params,
+        bytes memory wrappedCallData,
+        uint256 sellAmount
+    )
+        internal
+    {
+        // Swallow reverts
+        (bool success, bytes memory resultData) = _implementation.delegatecall(
+            abi.encodeWithSelector(
+                this._batchSellLiquidityProviderExternal.selector,
+                params,
+                wrappedCallData,
+                sellAmount
+            )
+        );
+        if (success) {
+            // Decode the output token amount on success.
+            uint256 boughtAmount = abi.decode(resultData, (uint256));
+            // Increment the sold and bought amounts.
+            state.soldAmount = state.soldAmount.safeAdd(sellAmount);
+            state.boughtAmount = state.boughtAmount.safeAdd(boughtAmount);
+        }
+    }
+
+    // This function is called after tokens have already been transferred
+    // into the liquidity provider contract (in the previous hop).
+    function _multiHopSellLiquidityProvider(
+        IMultiplexFeature.MultiHopSellState memory state,
+        IMultiplexFeature.MultiHopSellParams memory params,
+        bytes memory wrappedCallData
+    )
+        internal
+    {
+        IERC20TokenV06 inputToken = IERC20TokenV06(params.tokens[state.hopIndex]);
+        IERC20TokenV06 outputToken = IERC20TokenV06(params.tokens[state.hopIndex + 1]);
+        // Decode the provider address and auxiliary data.
+        (address provider, bytes memory auxiliaryData) = abi.decode(
+            wrappedCallData,
+            (address, bytes)
+        );
+        // Cache the recipient's balance of the output token.
+        uint256 balanceBefore = outputToken
+            .balanceOf(state.to);
+        // Execute the swap.
+        SANDBOX.executeSellTokenForToken(
+            ILiquidityProvider(provider),
+            inputToken,
+            outputToken,
+            state.to,
+            0,
+            auxiliaryData
+        );
+        // The previous `ouputTokenAmount` was effectively the
+        // input amount for this call. Cache the value before
+        // overwriting it with the new output token amount so
+        // that both the input and ouput amounts can be in the
+        // `LiquidityProviderSwap` event.
+        uint256 sellAmount = state.outputTokenAmount;
+        // Compute amount of output token received by the
+        // recipient.
+        state.outputTokenAmount = outputToken
+            .balanceOf(state.to)
+            .safeSub(balanceBefore);
+
+        emit LiquidityProviderSwap(
+            address(inputToken),
+            address(outputToken),
+            sellAmount,
+            state.outputTokenAmount,
+            provider,
+            state.to
+        );
+    }
+}

contracts/zero-ex/contracts/src/features/multiplex/MultiplexOtc.sol

@@ -0,0 +1,94 @@
+// 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-utils/contracts/src/v06/LibSafeMathV06.sol";
+import "../../fixins/FixinEIP712.sol";
+import "../interfaces/IMultiplexFeature.sol";
+import "../interfaces/IOtcOrdersFeature.sol";
+import "../libs/LibNativeOrder.sol";
+
+
+abstract contract MultiplexOtc is
+    FixinEIP712
+{
+    using LibSafeMathV06 for uint256;
+
+    event ExpiredOtcOrder(
+        bytes32 orderHash,
+        address maker,
+        uint64 expiry
+    );
+
+    function _batchSellOtcOrder(
+        IMultiplexFeature.BatchSellState memory state,
+        IMultiplexFeature.BatchSellParams memory params,
+        bytes memory wrappedCallData,
+        uint256 sellAmount
+    )
+        internal
+    {
+        // Decode the Otc order and signature.
+        (
+            LibNativeOrder.OtcOrder memory order,
+            LibSignature.Signature memory signature
+        ) = abi.decode(
+            wrappedCallData,
+            (LibNativeOrder.OtcOrder, LibSignature.Signature)
+        );
+        // Validate tokens.
+        require(
+            order.takerToken == params.inputToken &&
+            order.makerToken == params.outputToken,
+            "MultiplexOtc::_batchSellOtcOrder/OTC_ORDER_INVALID_TOKENS"
+        );
+        // Pre-emptively check if the order is expired.
+        uint64 expiry = uint64(order.expiryAndNonce >> 192);
+        if (expiry <= uint64(block.timestamp)) {
+            bytes32 orderHash = _getEIP712Hash(
+                LibNativeOrder.getOtcOrderStructHash(order)
+            );
+            emit ExpiredOtcOrder(
+                orderHash,
+                order.maker,
+                expiry
+            );
+            return;
+        }
+        // Try filling the Otc order. Swallows reverts.
+        try
+            IOtcOrdersFeature(address(this))._fillOtcOrder
+                (
+                    order,
+                    signature,
+                    sellAmount.safeDowncastToUint128(),
+                    msg.sender,
+                    params.useSelfBalance,
+                    params.recipient
+                )
+            returns (uint128 takerTokenFilledAmount, uint128 makerTokenFilledAmount)
+        {
+            // Increment the sold and bought amounts.
+            state.soldAmount = state.soldAmount.safeAdd(takerTokenFilledAmount);
+            state.boughtAmount = state.boughtAmount.safeAdd(makerTokenFilledAmount);
+        } catch {}
+    }
+}

contracts/zero-ex/contracts/src/features/multiplex/MultiplexRfq.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-utils/contracts/src/v06/LibSafeMathV06.sol";
+import "../../fixins/FixinEIP712.sol";
+import "../interfaces/IMultiplexFeature.sol";
+import "../interfaces/INativeOrdersFeature.sol";
+import "../libs/LibNativeOrder.sol";
+
+
+abstract contract MultiplexRfq is
+    FixinEIP712
+{
+    using LibSafeMathV06 for uint256;
+
+    event ExpiredRfqOrder(
+        bytes32 orderHash,
+        address maker,
+        uint64 expiry
+    );
+
+    function _batchSellRfqOrder(
+        IMultiplexFeature.BatchSellState memory state,
+        IMultiplexFeature.BatchSellParams memory params,
+        bytes memory wrappedCallData,
+        uint256 sellAmount
+    )
+        internal
+    {
+        // Decode the RFQ order and signature.
+        (
+            LibNativeOrder.RfqOrder memory order,
+            LibSignature.Signature memory signature
+        ) = abi.decode(
+            wrappedCallData,
+            (LibNativeOrder.RfqOrder, LibSignature.Signature)
+        );
+        // Pre-emptively check if the order is expired.
+        if (order.expiry <= uint64(block.timestamp)) {
+            bytes32 orderHash = _getEIP712Hash(
+                LibNativeOrder.getRfqOrderStructHash(order)
+            );
+            emit ExpiredRfqOrder(
+                orderHash,
+                order.maker,
+                order.expiry
+            );
+            return;
+        }
+        // Validate tokens.
+        require(
+            order.takerToken == params.inputToken &&
+            order.makerToken == params.outputToken,
+            "MultiplexRfq::_batchSellRfqOrder/RFQ_ORDER_INVALID_TOKENS"
+        );
+        // Try filling the RFQ order. Swallows reverts.
+        try
+            INativeOrdersFeature(address(this))._fillRfqOrder
+                (
+                    order,
+                    signature,
+                    sellAmount.safeDowncastToUint128(),
+                    msg.sender,
+                    params.useSelfBalance,
+                    params.recipient
+                )
+            returns (uint128 takerTokenFilledAmount, uint128 makerTokenFilledAmount)
+        {
+            // Increment the sold and bought amounts.
+            state.soldAmount = state.soldAmount.safeAdd(takerTokenFilledAmount);
+            state.boughtAmount = state.boughtAmount.safeAdd(makerTokenFilledAmount);
+        } catch {}
+    }
+}

contracts/zero-ex/contracts/src/features/multiplex/MultiplexTransformERC20.sol

@@ -0,0 +1,64 @@
+// 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-utils/contracts/src/v06/LibSafeMathV06.sol";
+import "../interfaces/IMultiplexFeature.sol";
+import "../interfaces/ITransformERC20Feature.sol";
+
+
+abstract contract MultiplexTransformERC20 {
+
+    using LibSafeMathV06 for uint256;
+
+    function _batchSellTransformERC20(
+        IMultiplexFeature.BatchSellState memory state,
+        IMultiplexFeature.BatchSellParams memory params,
+        bytes memory wrappedCallData,
+        uint256 sellAmount
+    )
+        internal
+    {
+        ITransformERC20Feature.TransformERC20Args memory args;
+        // We want the TransformedERC20 event to have
+        // `msg.sender` as the taker.
+        args.taker = msg.sender;
+        args.inputToken = params.inputToken;
+        args.outputToken = params.outputToken;
+        args.inputTokenAmount = sellAmount;
+        args.minOutputTokenAmount = 0;
+        args.useSelfBalance = params.useSelfBalance;
+        args.recipient = payable(params.recipient);
+        (args.transformations) = abi.decode(
+            wrappedCallData,
+            (ITransformERC20Feature.Transformation[])
+        );
+        // Execute the transformations and swallow reverts.
+        try ITransformERC20Feature(address(this))._transformERC20
+            (args)
+            returns (uint256 outputTokenAmount)
+        {
+            // Increment the sold and bought amounts.
+            state.soldAmount = state.soldAmount.safeAdd(sellAmount);
+            state.boughtAmount = state.boughtAmount.safeAdd(outputTokenAmount);
+        } catch {}
+    }
+}

contracts/zero-ex/contracts/src/features/multiplex/MultiplexUniswapV2.sol

@@ -0,0 +1,290 @@
+// 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 "@0x/contracts-utils/contracts/src/v06/LibSafeMathV06.sol";
+import "../../fixins/FixinCommon.sol";
+import "../../fixins/FixinTokenSpender.sol";
+import "../../vendor/IUniswapV2Pair.sol";
+import "../interfaces/IMultiplexFeature.sol";
+
+
+abstract contract MultiplexUniswapV2 is
+    FixinCommon,
+    FixinTokenSpender
+{
+    using LibSafeMathV06 for uint256;
+
+    // address of the UniswapV2Factory contract.
+    address private immutable UNISWAP_FACTORY;
+    // address of the (Sushiswap) UniswapV2Factory contract.
+    address private immutable SUSHISWAP_FACTORY;
+    // Init code hash of the UniswapV2Pair contract.
+    bytes32 private immutable UNISWAP_PAIR_INIT_CODE_HASH;
+    // Init code hash of the (Sushiswap) UniswapV2Pair contract.
+    bytes32 private immutable SUSHISWAP_PAIR_INIT_CODE_HASH;
+
+    constructor(
+        address uniswapFactory,
+        address sushiswapFactory,
+        bytes32 uniswapPairInitCodeHash,
+        bytes32 sushiswapPairInitCodeHash
+    )
+        internal
+    {
+        UNISWAP_FACTORY = uniswapFactory;
+        SUSHISWAP_FACTORY = sushiswapFactory;
+        UNISWAP_PAIR_INIT_CODE_HASH = uniswapPairInitCodeHash;
+        SUSHISWAP_PAIR_INIT_CODE_HASH = sushiswapPairInitCodeHash;
+    }
+
+    // A payable external function that we can delegatecall to
+    // swallow reverts and roll back the input token transfer.
+    function _batchSellUniswapV2External(
+        IMultiplexFeature.BatchSellParams calldata params,
+        bytes calldata wrappedCallData,
+        uint256 sellAmount
+    )
+        external
+        payable
+        returns (uint256 boughtAmount)
+    {
+        // Revert is not a delegatecall.
+        require(
+            address(this) != _implementation,
+            "MultiplexLiquidityProvider::_batchSellUniswapV2External/ONLY_DELEGATECALL"
+        );
+
+        (address[] memory tokens, bool isSushi) = abi.decode(
+            wrappedCallData,
+            (address[], bool)
+        );
+        // Validate tokens
+        require(
+            tokens.length >= 2 &&
+            tokens[0] == address(params.inputToken) &&
+            tokens[tokens.length - 1] == address(params.outputToken),
+            "MultiplexUniswapV2::_batchSellUniswapV2/INVALID_TOKENS"
+        );
+        // Compute the address of the first Uniswap pair
+        // contract that will execute a swap.
+        address firstPairAddress = _computeUniswapPairAddress(
+            tokens[0],
+            tokens[1],
+            isSushi
+        );
+        // `_sellToUniswapV2` assumes the input tokens have been
+        // transferred into the pair contract before it is called,
+        // so we transfer the tokens in now (either from `msg.sender`
+        // or using the Exchange Proxy's balance).
+        if (params.useSelfBalance) {
+            _transferERC20Tokens(
+                IERC20TokenV06(tokens[0]),
+                firstPairAddress,
+                sellAmount
+            );
+        } else {
+            _transferERC20TokensFrom(
+                IERC20TokenV06(tokens[0]),
+                msg.sender,
+                firstPairAddress,
+                sellAmount
+            );
+        }
+        // Execute the Uniswap/Sushiswap trade.
+        return _sellToUniswapV2(
+            tokens,
+            sellAmount,
+            isSushi,
+            firstPairAddress,
+            params.recipient
+        );
+    }
+
+    function _batchSellUniswapV2(
+        IMultiplexFeature.BatchSellState memory state,
+        IMultiplexFeature.BatchSellParams memory params,
+        bytes memory wrappedCallData,
+        uint256 sellAmount
+    )
+        internal
+    {
+        // Swallow reverts
+        (bool success, bytes memory resultData) = _implementation.delegatecall(
+            abi.encodeWithSelector(
+                this._batchSellUniswapV2External.selector,
+                params,
+                wrappedCallData,
+                sellAmount
+            )
+        );
+        if (success) {
+            // Decode the output token amount on success.
+            uint256 boughtAmount = abi.decode(resultData, (uint256));
+            // Increment the sold and bought amounts.
+            state.soldAmount = state.soldAmount.safeAdd(sellAmount);
+            state.boughtAmount = state.boughtAmount.safeAdd(boughtAmount);
+        }
+    }
+
+    function _multiHopSellUniswapV2(
+        IMultiplexFeature.MultiHopSellState memory state,
+        IMultiplexFeature.MultiHopSellParams memory params,
+        bytes memory wrappedCallData
+    )
+        internal
+    {
+        (address[] memory tokens, bool isSushi) = abi.decode(
+            wrappedCallData,
+            (address[], bool)
+        );
+        // Validate the tokens
+        require(
+            tokens.length >= 2 &&
+            tokens[0] == params.tokens[state.hopIndex] &&
+            tokens[tokens.length - 1] == params.tokens[state.hopIndex + 1],
+            "MultiplexUniswapV2::_multiHopSellUniswapV2/INVALID_TOKENS"
+        );
+        // Execute the Uniswap/Sushiswap trade.
+        state.outputTokenAmount = _sellToUniswapV2(
+            tokens,
+            state.outputTokenAmount,
+            isSushi,
+            state.from,
+            state.to
+        );
+    }
+
+    function _sellToUniswapV2(
+        address[] memory tokens,
+        uint256 sellAmount,
+        bool isSushi,
+        address pairAddress,
+        address recipient
+    )
+        private
+        returns (uint256 outputTokenAmount)
+    {
+        // Iterate through `tokens` perform a swap against the Uniswap
+        // pair contract for each `(tokens[i], tokens[i+1])`.
+        for (uint256 i = 0; i < tokens.length - 1; i++) {
+            (address inputToken, address outputToken) = (tokens[i], tokens[i + 1]);
+            // Compute the output token amount
+            outputTokenAmount = _computeUniswapOutputAmount(
+                pairAddress,
+                inputToken,
+                outputToken,
+                sellAmount
+            );
+            (uint256 amount0Out, uint256 amount1Out) = inputToken < outputToken
+                ? (uint256(0), outputTokenAmount)
+                : (outputTokenAmount, uint256(0));
+            // The Uniswap pair contract will transfer the output tokens to
+            // the next pair contract if there is one, otherwise transfer to
+            // `recipient`.
+            address to = i < tokens.length - 2
+                ? _computeUniswapPairAddress(outputToken, tokens[i + 2], isSushi)
+                : recipient;
+            // Execute the swap.
+            IUniswapV2Pair(pairAddress).swap(
+                amount0Out,
+                amount1Out,
+                to,
+                new bytes(0)
+            );
+            // To avoid recomputing the pair address of the next pair, store
+            // `to` in `pairAddress`.
+            pairAddress = to;
+            // The outputTokenAmount
+            sellAmount = outputTokenAmount;
+        }
+    }
+
+    // Computes the Uniswap/Sushiswap pair contract address for the
+    // given tokens.
+    function _computeUniswapPairAddress(
+        address tokenA,
+        address tokenB,
+        bool isSushi
+    )
+        internal
+        view
+        returns (address pairAddress)
+    {
+        // Tokens are lexicographically sorted in the Uniswap contract.
+        (address token0, address token1) = tokenA < tokenB
+            ? (tokenA, tokenB)
+            : (tokenB, tokenA);
+        if (isSushi) {
+            // Use the Sushiswap factory address and codehash
+            return address(uint256(keccak256(abi.encodePacked(
+                hex'ff',
+                SUSHISWAP_FACTORY,
+                keccak256(abi.encodePacked(token0, token1)),
+                SUSHISWAP_PAIR_INIT_CODE_HASH
+            ))));
+        } else {
+            // Use the Uniswap factory address and codehash
+            return address(uint256(keccak256(abi.encodePacked(
+                hex'ff',
+                UNISWAP_FACTORY,
+                keccak256(abi.encodePacked(token0, token1)),
+                UNISWAP_PAIR_INIT_CODE_HASH
+            ))));
+        }
+    }
+
+    // Computes the the amount of output token that would be bought
+    // from Uniswap/Sushiswap given the input amount.
+    function _computeUniswapOutputAmount(
+        address pairAddress,
+        address inputToken,
+        address outputToken,
+        uint256 inputAmount
+    )
+        private
+        view
+        returns (uint256 outputAmount)
+    {
+        // Input amount should be non-zero.
+        require(
+            inputAmount > 0,
+            "MultiplexUniswapV2::_computeUniswapOutputAmount/INSUFFICIENT_INPUT_AMOUNT"
+        );
+        // Query the reserves of the pair contract.
+        (uint256 reserve0, uint256 reserve1,) = IUniswapV2Pair(pairAddress).getReserves();
+        // Reserves must be non-zero.
+        require(
+            reserve0 > 0 && reserve1 > 0,
+            'MultiplexUniswapV2::_computeUniswapOutputAmount/INSUFFICIENT_LIQUIDITY'
+        );
+        // Tokens are lexicographically sorted in the Uniswap contract.
+        (uint256 inputReserve, uint256 outputReserve) = inputToken < outputToken
+            ? (reserve0, reserve1)
+            : (reserve1, reserve0);
+        // Compute the output amount.
+        uint256 inputAmountWithFee = inputAmount.safeMul(997);
+        uint256 numerator = inputAmountWithFee.safeMul(outputReserve);
+        uint256 denominator = inputReserve.safeMul(1000).safeAdd(inputAmountWithFee);
+        return numerator / denominator;
+    }
+}

contracts/zero-ex/contracts/src/features/multiplex/MultiplexUniswapV3.sol

@@ -0,0 +1,123 @@
+// 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 "@0x/contracts-utils/contracts/src/v06/LibSafeMathV06.sol";
+import "../../fixins/FixinTokenSpender.sol";
+import "../interfaces/IMultiplexFeature.sol";
+import "../interfaces/IUniswapV3Feature.sol";
+
+
+abstract contract MultiplexUniswapV3 is
+    FixinTokenSpender
+{
+    using LibSafeMathV06 for uint256;
+
+    function _batchSellUniswapV3(
+        IMultiplexFeature.BatchSellState memory state,
+        IMultiplexFeature.BatchSellParams memory params,
+        bytes memory wrappedCallData,
+        uint256 sellAmount
+    )
+        internal
+    {
+        bool success;
+        bytes memory resultData;
+        if (params.useSelfBalance) {
+            // If the tokens are held by `address(this)`, we call
+            // the `onlySelf` variant `_sellHeldTokenForTokenToUniswapV3`,
+            // which uses the Exchange Proxy's balance of input token.
+            (success, resultData) = address(this).call(
+                abi.encodeWithSelector(
+                    IUniswapV3Feature._sellHeldTokenForTokenToUniswapV3.selector,
+                    wrappedCallData,
+                    sellAmount,
+                    0,
+                    params.recipient
+                )
+            );
+        } else {
+            // Otherwise, we self-delegatecall the normal variant
+            // `sellTokenForTokenToUniswapV3`, which pulls the input token
+            // from `msg.sender`.
+            (success, resultData) = address(this).delegatecall(
+                abi.encodeWithSelector(
+                    IUniswapV3Feature.sellTokenForTokenToUniswapV3.selector,
+                    wrappedCallData,
+                    sellAmount,
+                    0,
+                    params.recipient
+                )
+            );
+        }
+        if (success) {
+            // Decode the output token amount on success.
+            uint256 outputTokenAmount = abi.decode(resultData, (uint256));
+            // Increment the sold and bought amounts.
+            state.soldAmount = state.soldAmount.safeAdd(sellAmount);
+            state.boughtAmount = state.boughtAmount.safeAdd(outputTokenAmount);
+        }
+    }
+
+    function _multiHopSellUniswapV3(
+        IMultiplexFeature.MultiHopSellState memory state,
+        bytes memory wrappedCallData
+    )
+        internal
+    {
+        bool success;
+        bytes memory resultData;
+        if (state.from == address(this)) {
+            // If the tokens are held by `address(this)`, we call
+            // the `onlySelf` variant `_sellHeldTokenForTokenToUniswapV3`,
+            // which uses the Exchange Proxy's balance of input token.
+            (success, resultData) = address(this).call(
+                abi.encodeWithSelector(
+                    IUniswapV3Feature._sellHeldTokenForTokenToUniswapV3.selector,
+                    wrappedCallData,
+                    state.outputTokenAmount,
+                    0,
+                    state.to
+                )
+            );
+        } else {
+            // Otherwise, we self-delegatecall the normal variant
+            // `sellTokenForTokenToUniswapV3`, which pulls the input token
+            // from `msg.sender`.
+            (success, resultData) = address(this).delegatecall(
+                abi.encodeWithSelector(
+                    IUniswapV3Feature.sellTokenForTokenToUniswapV3.selector,
+                    wrappedCallData,
+                    state.outputTokenAmount,
+                    0,
+                    state.to
+                )
+            );
+        }
+        if (success) {
+            // Decode the output token amount on success.
+            state.outputTokenAmount = abi.decode(resultData, (uint256));
+        } else {
+            revert("MultiplexUniswapV3::_multiHopSellUniswapV3/SWAP_FAILED");
+        }
+    }
+}

contracts/zero-ex/contracts/src/features/native_orders/NativeOrdersSettlement.sol

@@ -52,8 +52,10 @@ abstract contract NativeOrdersSettlement is
         bytes32 orderHash;
         // Maker of the order.
         address maker;
-        // Taker of the order.
-        address taker;
+        // The address holding the taker tokens.
+        address payer;
+        // Recipient of the maker tokens.
+        address recipient;
         // Maker token.
         IERC20TokenV06 makerToken;
         // Taker token.
@@ -82,6 +84,22 @@ abstract contract NativeOrdersSettlement is
         address sender;
     }
 
+    /// @dev Params for `_fillRfqOrderPrivate()`
+    struct FillRfqOrderPrivateParams {
+        LibNativeOrder.RfqOrder order;
+        // The order signature.
+        LibSignature.Signature signature;
+        // Maximum taker token to fill this order with.
+        uint128 takerTokenFillAmount;
+        // The order taker.
+        address taker;
+        // Whether to use the Exchange Proxy's balance
+        // of taker tokens.
+        bool useSelfBalance;
+        // The recipient of the maker tokens.
+        address recipient;
+    }
+
     // @dev Fill results returned by `_fillLimitOrderPrivate()` and
     ///     `_fillRfqOrderPrivate()`.
     struct FillNativeOrderResults {
@@ -154,12 +172,14 @@ abstract contract NativeOrdersSettlement is
         returns (uint128 takerTokenFilledAmount, uint128 makerTokenFilledAmount)
     {
         FillNativeOrderResults memory results =
-            _fillRfqOrderPrivate(
-                order,
-                signature,
-                takerTokenFillAmount,
-                msg.sender
-            );
+            _fillRfqOrderPrivate(FillRfqOrderPrivateParams({
+                order: order,
+                signature: signature,
+                takerTokenFillAmount: takerTokenFillAmount,
+                taker: msg.sender,
+                useSelfBalance: false,
+                recipient: msg.sender
+            }));
         (takerTokenFilledAmount, makerTokenFilledAmount) = (
             results.takerTokenFilledAmount,
             results.makerTokenFilledAmount
@@ -220,12 +240,14 @@ abstract contract NativeOrdersSettlement is
         returns (uint128 makerTokenFilledAmount)
     {
         FillNativeOrderResults memory results =
-            _fillRfqOrderPrivate(
-                order,
-                signature,
-                takerTokenFillAmount,
-                msg.sender
-            );
+            _fillRfqOrderPrivate(FillRfqOrderPrivateParams({
+                order: order,
+                signature: signature,
+                takerTokenFillAmount: takerTokenFillAmount,
+                taker: msg.sender,
+                useSelfBalance: false,
+                recipient: msg.sender
+            }));
         // Must have filled exactly the amount requested.
         if (results.takerTokenFilledAmount < takerTokenFillAmount) {
             LibNativeOrdersRichErrors.FillOrKillFailedError(
@@ -260,33 +282,36 @@ abstract contract NativeOrdersSettlement is
         returns (uint128 takerTokenFilledAmount, uint128 makerTokenFilledAmount)
     {
         FillNativeOrderResults memory results =
-            _fillLimitOrderPrivate(FillLimitOrderPrivateParams({
-                order: order,
-                signature: signature,
-                takerTokenFillAmount: takerTokenFillAmount,
-                taker: taker,
-                sender: sender
-            }));
+            _fillLimitOrderPrivate(FillLimitOrderPrivateParams(
+                order,
+                signature,
+                takerTokenFillAmount,
+                taker,
+                sender
+            ));
         (takerTokenFilledAmount, makerTokenFilledAmount) = (
             results.takerTokenFilledAmount,
             results.makerTokenFilledAmount
         );
     }
 
-    /// @dev Fill an RFQ order. Internal variant. ETH protocol fees can be
-    ///      attached to this call. Any unspent ETH will be refunded to
-    ///      `msg.sender` (not `sender`).
+    /// @dev Fill an RFQ order. Internal variant.
     /// @param order The RFQ order.
     /// @param signature The order signature.
     /// @param takerTokenFillAmount Maximum taker token to fill this order with.
     /// @param taker The order taker.
+    /// @param useSelfBalance Whether to use the ExchangeProxy's transient
+    ///        balance of taker tokens to fill the order.
+    /// @param recipient The recipient of the maker tokens.
     /// @return takerTokenFilledAmount How much maker token was filled.
     /// @return makerTokenFilledAmount How much maker token was filled.
     function _fillRfqOrder(
         LibNativeOrder.RfqOrder memory order,
         LibSignature.Signature memory signature,
         uint128 takerTokenFillAmount,
-        address taker
+        address taker,
+        bool useSelfBalance,
+        address recipient
     )
         public
         virtual
@@ -294,12 +319,14 @@ abstract contract NativeOrdersSettlement is
         returns (uint128 takerTokenFilledAmount, uint128 makerTokenFilledAmount)
     {
         FillNativeOrderResults memory results =
-            _fillRfqOrderPrivate(
+            _fillRfqOrderPrivate(FillRfqOrderPrivateParams(
                 order,
                 signature,
                 takerTokenFillAmount,
-                taker
-            );
+                taker,
+                useSelfBalance,
+                recipient
+            ));
         (takerTokenFilledAmount, makerTokenFilledAmount) = (
             results.takerTokenFilledAmount,
             results.makerTokenFilledAmount
@@ -387,7 +414,8 @@ abstract contract NativeOrdersSettlement is
             SettleOrderInfo({
                 orderHash: orderInfo.orderHash,
                 maker: params.order.maker,
-                taker: params.taker,
+                payer: params.taker,
+                recipient: params.taker,
                 makerToken: IERC20TokenV06(params.order.makerToken),
                 takerToken: IERC20TokenV06(params.order.takerToken),
                 makerAmount: params.order.makerAmount,
@@ -404,7 +432,7 @@ abstract contract NativeOrdersSettlement is
                 params.order.takerAmount,
                 params.order.takerTokenFeeAmount
             ));
-            _transferERC20Tokens(
+            _transferERC20TokensFrom(
                 params.order.takerToken,
                 params.taker,
                 params.order.feeRecipient,
@@ -427,22 +455,14 @@ abstract contract NativeOrdersSettlement is
         );
     }
 
-    /// @dev Fill an RFQ order. Private variant. Does not refund protocol fees.
-    /// @param order The RFQ order.
-    /// @param signature The order signature.
-    /// @param takerTokenFillAmount Maximum taker token to fill this order with.
-    /// @param taker The order taker.
+    /// @dev Fill an RFQ order. Private variant.
+    /// @param params Function params.
     /// @return results Results of the fill.
-    function _fillRfqOrderPrivate(
-        LibNativeOrder.RfqOrder memory order,
-        LibSignature.Signature memory signature,
-        uint128 takerTokenFillAmount,
-        address taker
-    )
+    function _fillRfqOrderPrivate(FillRfqOrderPrivateParams memory params)
         private
         returns (FillNativeOrderResults memory results)
     {
-        LibNativeOrder.OrderInfo memory orderInfo = getRfqOrderInfo(order);
+        LibNativeOrder.OrderInfo memory orderInfo = getRfqOrderInfo(params.order);
 
         // Must be fillable.
         if (orderInfo.status != LibNativeOrder.OrderStatus.FILLABLE) {
@@ -457,32 +477,41 @@ abstract contract NativeOrdersSettlement is
                 LibNativeOrdersStorage.getStorage();
 
             // Must be fillable by the tx.origin.
-            if (order.txOrigin != tx.origin && !stor.originRegistry[order.txOrigin][tx.origin]) {
+            if (
+                params.order.txOrigin != tx.origin &&
+                !stor.originRegistry[params.order.txOrigin][tx.origin]
+            ) {
                 LibNativeOrdersRichErrors.OrderNotFillableByOriginError(
                     orderInfo.orderHash,
                     tx.origin,
-                    order.txOrigin
+                    params.order.txOrigin
                 ).rrevert();
             }
         }
 
         // Must be fillable by the taker.
-        if (order.taker != address(0) && order.taker != taker) {
+        if (params.order.taker != address(0) && params.order.taker != params.taker) {
             LibNativeOrdersRichErrors.OrderNotFillableByTakerError(
                 orderInfo.orderHash,
-                taker,
-                order.taker
+                params.taker,
+                params.order.taker
             ).rrevert();
         }
 
         // Signature must be valid for the order.
         {
-            address signer = LibSignature.getSignerOfHash(orderInfo.orderHash, signature);
-            if (signer != order.maker && !isValidOrderSigner(order.maker, signer)) {
+            address signer = LibSignature.getSignerOfHash(
+                orderInfo.orderHash,
+                params.signature
+            );
+            if (
+                signer != params.order.maker &&
+                !isValidOrderSigner(params.order.maker, signer)
+            ) {
                 LibNativeOrdersRichErrors.OrderNotSignedByMakerError(
                     orderInfo.orderHash,
                     signer,
-                    order.maker
+                    params.order.maker
                 ).rrevert();
             }
         }
@@ -491,26 +520,27 @@ abstract contract NativeOrdersSettlement is
         (results.takerTokenFilledAmount, results.makerTokenFilledAmount) = _settleOrder(
             SettleOrderInfo({
                 orderHash: orderInfo.orderHash,
-                maker: order.maker,
-                taker: taker,
-                makerToken: IERC20TokenV06(order.makerToken),
-                takerToken: IERC20TokenV06(order.takerToken),
-                makerAmount: order.makerAmount,
-                takerAmount: order.takerAmount,
-                takerTokenFillAmount: takerTokenFillAmount,
+                maker: params.order.maker,
+                payer: params.useSelfBalance ? address(this) : params.taker,
+                recipient: params.recipient,
+                makerToken: IERC20TokenV06(params.order.makerToken),
+                takerToken: IERC20TokenV06(params.order.takerToken),
+                makerAmount: params.order.makerAmount,
+                takerAmount: params.order.takerAmount,
+                takerTokenFillAmount: params.takerTokenFillAmount,
                 takerTokenFilledAmount: orderInfo.takerTokenFilledAmount
             })
         );
 
         emit RfqOrderFilled(
             orderInfo.orderHash,
-            order.maker,
-            taker,
-            address(order.makerToken),
-            address(order.takerToken),
+            params.order.maker,
+            params.taker,
+            address(params.order.makerToken),
+            address(params.order.takerToken),
             results.takerTokenFilledAmount,
             results.makerTokenFilledAmount,
-            order.pool
+            params.order.pool
         );
     }
 
@@ -549,19 +579,28 @@ abstract contract NativeOrdersSettlement is
             // function if the order is cancelled.
                 settleInfo.takerTokenFilledAmount.safeAdd128(takerTokenFilledAmount);
 
-        // Transfer taker -> maker.
-        _transferERC20Tokens(
-            settleInfo.takerToken,
-            settleInfo.taker,
-            settleInfo.maker,
-            takerTokenFilledAmount
-        );
+        if (settleInfo.payer == address(this)) {
+            // Transfer this -> maker.
+            _transferERC20Tokens(
+                settleInfo.takerToken,
+                settleInfo.maker,
+                takerTokenFilledAmount
+            );
+        } else {
+            // Transfer taker -> maker.
+            _transferERC20TokensFrom(
+                settleInfo.takerToken,
+                settleInfo.payer,
+                settleInfo.maker,
+                takerTokenFilledAmount
+            );
+        }
 
-        // Transfer maker -> taker.
-        _transferERC20Tokens(
+        // Transfer maker -> recipient.
+        _transferERC20TokensFrom(
             settleInfo.makerToken,
             settleInfo.maker,
-            settleInfo.taker,
+            settleInfo.recipient,
             makerTokenFilledAmount
         );
     }

contracts/zero-ex/contracts/src/fixins/FixinTokenSpender.sol

@@ -35,7 +35,7 @@ abstract contract FixinTokenSpender {
     /// @param owner The owner of the tokens.
     /// @param to The recipient of the tokens.
     /// @param amount The amount of `token` to transfer.
-    function _transferERC20Tokens(
+    function _transferERC20TokensFrom(
         IERC20TokenV06 token,
         address owner,
         address to,
@@ -87,6 +87,60 @@ abstract contract FixinTokenSpender {
         }
     }
 
+    /// @dev Transfers ERC20 tokens from ourselves to `to`.
+    /// @param token The token to spend.
+    /// @param to The recipient of the tokens.
+    /// @param amount The amount of `token` to transfer.
+    function _transferERC20Tokens(
+        IERC20TokenV06 token,
+        address to,
+        uint256 amount
+    )
+        internal
+    {
+        require(address(token) != address(this), "FixinTokenSpender/CANNOT_INVOKE_SELF");
+
+        assembly {
+            let ptr := mload(0x40) // free memory pointer
+
+            // selector for transfer(address,uint256)
+            mstore(ptr, 0xa9059cbb00000000000000000000000000000000000000000000000000000000)
+            mstore(add(ptr, 0x04), and(to, ADDRESS_MASK))
+            mstore(add(ptr, 0x24), amount)
+
+            let success := call(
+                gas(),
+                and(token, ADDRESS_MASK),
+                0,
+                ptr,
+                0x44,
+                ptr,
+                32
+            )
+
+            let rdsize := returndatasize()
+
+            // Check for ERC20 success. ERC20 tokens should return a boolean,
+            // but some don't. We accept 0-length return data as success, or at
+            // least 32 bytes that starts with a 32-byte boolean true.
+            success := and(
+                success,                             // call itself succeeded
+                or(
+                    iszero(rdsize),                  // no return data, or
+                    and(
+                        iszero(lt(rdsize, 32)),      // at least 32 bytes
+                        eq(mload(ptr), 1)            // starts with uint256(1)
+                    )
+                )
+            )
+
+            if iszero(success) {
+                returndatacopy(ptr, 0, rdsize)
+                revert(ptr, rdsize)
+            }
+        }
+    }
+
     /// @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.