Publish

- 0x.js@3.0.0 - @0x/abi-gen@1.0.20 - @0x/abi-gen-wrappers@2.1.0 - @0x/assert@1.0.21 - @0x/asset-buyer@3.0.5 - @0x/base-contract@3.0.11 - @0x/connect@3.0.11 - @0x/contract-addresses@2.1.0 - @0x/contract-artifacts@1.2.0 - @0x/contract-wrappers@4.2.0 - @0x/dev-tools-pages@0.0.11 - @0x/dev-utils@1.0.22 - @0x/fill-scenarios@1.1.0 - @0x/instant@1.0.5 - @0x/json-schemas@2.1.5 - @0x/metacoin@0.0.33 - @0x/migrations@2.3.0 - @0x/monorepo-scripts@1.0.16 - @0x/order-utils@3.1.0 - @0x/order-watcher@2.4.0 - @0x/pipeline@1.0.3 - @0x/react-docs@1.0.23 - @0x/react-shared@1.1.0 - @0x/sol-compiler@2.0.0 - @0x/sol-cov@2.1.17 - @0x/sol-doc@1.0.12 - @0x/sol-resolver@1.2.1 - @0x/sra-spec@1.0.14 - @0x/subproviders@2.1.9 - @0x/testnet-faucets@1.0.61 - @0x/types@1.5.0 - @0x/utils@2.1.1 - @0x/web3-wrapper@3.2.2 - @0x/website@0.0.64 - @0x/contracts-examples@1.0.3 - @0x/contracts-extensions@1.2.0 - @0x/contracts-interfaces@1.0.3 - @0x/contracts-libs@1.0.3 - @0x/contracts-multisig@1.0.3 - @0x/contracts-protocol@2.2.0 - @0x/contracts-test-utils@1.0.3 - @0x/contracts-tokens@1.0.3 - @0x/contracts-utils@1.0.3
Updated CHANGELOGS
2019-01-09 14:44:17 +01:00 · 2019-01-09 14:44:03 +01:00 · 2019-01-09 13:22:20 +01:00 · 2019-01-09 12:46:51 +01:00 · 2019-01-09 12:36:05 +01:00 · 2019-01-09 12:35:35 +01:00
1213 changed files with 51441 additions and 6587 deletions
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -18,6 +18,7 @@ jobs:
                  name: yarn
                  command: yarn --frozen-lockfile install || yarn --frozen-lockfile install
            - run: yarn build:ci:no_website
+            - run: yarn build:ts
            - save_cache:
                  key: repo-{{ .Environment.CIRCLE_SHA1 }}
                  paths:
@@ -40,7 +41,12 @@ jobs:
            - restore_cache:
                  keys:
                      - repo-{{ .Environment.CIRCLE_SHA1 }}
-            - run: yarn wsrun test:circleci contracts
+            - run: yarn wsrun test:circleci @0x/contracts-multisig
+            - run: yarn wsrun test:circleci @0x/contracts-utils
+            - run: yarn wsrun test:circleci @0x/contracts-libs
+            - run: yarn wsrun test:circleci @0x/contracts-tokens
+            - run: yarn wsrun test:circleci @0x/contracts-extensions
+            - run: yarn wsrun test:circleci @0x/contracts-protocol
    test-contracts-geth:
        docker:
            - image: circleci/node:9
@@ -52,7 +58,12 @@ jobs:
                      - repo-{{ .Environment.CIRCLE_SHA1 }}
            # HACK(albrow): we need to sleep 10 seconds to ensure the devnet is
            # initialized
-            - run: sleep 10 && TEST_PROVIDER=geth yarn wsrun test contracts
+            - run: sleep 10 && TEST_PROVIDER=geth yarn wsrun test @0x/contracts-multisig
+            - run: TEST_PROVIDER=geth yarn wsrun test @0x/contracts-utils
+            - run: TEST_PROVIDER=geth yarn wsrun test @0x/contracts-libs
+            - run: TEST_PROVIDER=geth yarn wsrun test @0x/contracts-tokens
+            - run: TEST_PROVIDER=geth yarn wsrun test @0x/contracts-extensions
+            - run: TEST_PROVIDER=geth yarn wsrun test @0x/contracts-protocol
    test-publish:
        resource_class: medium+
        docker:
@@ -73,6 +84,20 @@ jobs:
                  keys:
                      - repo-{{ .Environment.CIRCLE_SHA1 }}
            - run: yarn test:generate_docs:circleci
+    test-pipeline:
+        docker:
+            - image: circleci/node:9
+            - image: postgres:11-alpine
+        working_directory: ~/repo
+        steps:
+            - restore_cache:
+                  keys:
+                      - repo-{{ .Environment.CIRCLE_SHA1 }}
+            - run: ZEROEX_DATA_PIPELINE_TEST_DB_URL='postgresql://postgres@localhost/postgres' yarn wsrun test:circleci @0x/pipeline
+            - save_cache:
+                  key: coverage-pipeline-{{ .Environment.CIRCLE_SHA1 }}
+                  paths:
+                      - ~/repo/packages/pipeline/coverage/lcov.info
    test-rest:
        docker:
            - image: circleci/node:9
@@ -81,6 +106,7 @@ jobs:
            - restore_cache:
                  keys:
                      - repo-{{ .Environment.CIRCLE_SHA1 }}
+            - run: yarn wsrun test:circleci @0x/contracts-test-utils
            - run: yarn wsrun test:circleci @0x/abi-gen
            - run: yarn wsrun test:circleci @0x/assert
            - run: yarn wsrun test:circleci @0x/base-contract
@@ -162,20 +188,37 @@ jobs:
        working_directory: ~/repo
        docker:
            - image: circleci/python
-            - image: 0xorg/ganache-cli
+            - image: 0xorg/ganache-cli:2.2.2
+            - image: 0xorg/launch-kit-ci
              command: |
-                  ganache-cli --gasLimit 10000000 --noVMErrorsOnRPCResponse --db /snapshot --noVMErrorsOnRPCResponse -p 8545 --networkId 50 -m "concert load couple harbor equip island argue ramp clarify fence smart topic"
+                  yarn start:ts -p 3000:3000
        steps:
            - checkout
            - run: sudo chown -R circleci:circleci /usr/local/bin
            - run: sudo chown -R circleci:circleci /usr/local/lib/python3.7/site-packages
            - restore_cache:
                  key: deps9-{{ .Branch }}-{{ .Environment.CIRCLE_SHA1 }}
+            - run:
+                  command: |
+                      cd python-packages/json_schemas
+                      python -m ensurepip
+                      python -m pip install .[dev]
+                      # HACK! installing the package should do the following
+                      # copy for us, but it's not working in CircleCI for some
+                      # reason.  Zendesk support ticket raised (#43979) with
+                      # CircleCI.
+                      mkdir /usr/local/lib/python3.7/site-packages/zero_ex/json_schemas/schemas
+                      cp -R src/zero_ex/json_schemas/schemas/* /usr/local/lib/python3.7/site-packages/zero_ex/json_schemas/schemas
            - run:
                  command: |
                      cd python-packages/order_utils
                      python -m ensurepip
-                      python -m pip install -e .[dev]
+                      python -m pip install .[dev]
+            - run:
+                  command: |
+                      cd python-packages/sra_client
+                      python -m ensurepip
+                      python -m pip install .[dev]
            - save_cache:
                  key: deps9-{{ .Branch }}-{{ .Environment.CIRCLE_SHA1 }}
                  paths:
@@ -185,14 +228,30 @@ jobs:
                      - '.mypy_cache'
                      - '.pytest_cache'
                      - '.tox'
+            - run:
+                  command: |
+                      cd python-packages/json_schemas
+                      coverage run setup.py test
            - run:
                  command: |
                      cd python-packages/order_utils
                      coverage run setup.py test
+            - run:
+                  command: |
+                      cd python-packages/sra_client
+                      coverage run setup.py test
+            - save_cache:
+                  key: coverage-python-json-schemas-{{ .Environment.CIRCLE_SHA1 }}
+                  paths:
+                      - ~/repo/python-packages/json_schemas/.coverage
            - save_cache:
                  key: coverage-python-order-utils-{{ .Environment.CIRCLE_SHA1 }}
                  paths:
                      - ~/repo/python-packages/order_utils/.coverage
+            - save_cache:
+                  key: coverage-python-sra-client-{{ .Environment.CIRCLE_SHA1 }}
+                  paths:
+                      - ~/repo/python-packages/sra_client/.coverage
    test-rest-python:
        working_directory: ~/repo
        docker:
@@ -207,7 +266,7 @@ jobs:
                  command: |
                      cd python-packages/order_utils
                      python -m ensurepip
-                      python -m pip install -e .[dev]
+                      python -m pip install .
            - save_cache:
                  key: deps9-{{ .Branch }}-{{ .Environment.CIRCLE_SHA1 }}
                  paths:
@@ -231,16 +290,25 @@ jobs:
            - run: sudo chown -R circleci:circleci /usr/local/lib/python3.7/site-packages
            - restore_cache:
                  key: deps9-{{ .Branch }}-{{ .Environment.CIRCLE_SHA1 }}
+            - run:
+                  command: |
+                      cd python-packages/json_schemas
+                      python -m ensurepip
+                      python -m pip install .[dev]
            - run:
                  command: |
                      cd python-packages/order_utils
                      python -m ensurepip
-                      python -m pip install -e .[dev]
+                      python -m pip install .[dev]
            - save_cache:
                  key: deps9-{{ .Branch }}-{{ .Environment.CIRCLE_SHA1 }}
                  paths:
                      - '/usr/local/bin'
                      - '/usr/local/lib/python3.7/site-packages'
+            - run:
+                  command: |
+                      cd python-packages/json_schemas
+                      python setup.py lint
            - run:
                  command: |
                      cd python-packages/order_utils
@@ -313,6 +381,9 @@ jobs:
            - restore_cache:
                  keys:
                      - coverage-contracts-{{ .Environment.CIRCLE_SHA1 }}
+            - restore_cache:
+                  keys:
+                      - coverage-python-json-schemas-{{ .Environment.CIRCLE_SHA1 }}
            - restore_cache:
                  keys:
                      - coverage-python-order-utils-{{ .Environment.CIRCLE_SHA1 }}
@@ -331,6 +402,9 @@ workflows:
            - test-contracts-geth:
                  requires:
                      - build
+            - test-pipeline:
+                  requires:
+                      - build
            - test-rest:
                  requires:
                      - build
--- a/.github/autolabeler.yml
+++ b/.github/autolabeler.yml
@@ -0,0 +1,39 @@
+python: ['python-packages']
+contracts: ['contracts']
+sol-doc: ['packages/sol-doc']
+sol-resolver: ['packages/sol-resolver']
+sra-spec: ['packages/sra-spec']
+subproviders: ['packages/subproviders']
+contract-addresses: ['packages/contract-addresses']
+migrations: ['packages/migrations']
+web3-wrapper: ['packages/web3-wrapper']
+sol-compiler: ['packages/sol-compiler']
+types: ['packages/types']
+instant: ['packages/instant']
+abi-gen-templates: ['packages/abi-gen-templates']
+abi-gen: ['packages/abi-gen']
+website: ['packages/website']
+sol-cov: ['packages/sol-cov']
+utils: ['packages/utils']
+tslint-config: ['packages/tslint-config']
+asset-buyer: ['packages/asset-buyer']
+order-watcher: ['packages/order-watcher']
+react-docs: ['packages/react-docs']
+order-utils: ['packages/order-utils']
+react-shared: ['packages/react-shared']
+assert: ['packages/assert']
+base-contract: ['packages/base-contract']
+typescript-typings: ['packages/typescript-typings']
+0x.js: ['packages/0x.js']
+abi-gen-wrappers: ['packages/abi-gen-wrappers']
+metacoin: ['packages/metacoin']
+contract-artifacts: ['packages/contract-artifacts']
+dev-utils: ['packages/dev-utils']
+contract-wrappers: ['packages/contract-wrappers']
+json-schemas: ['packages/json-schemas']
+ethereum-types: ['ethereum-types']
+connect: ['packages/connect']
+fill-scenarios: ['packages/fill-scenarios']
+dev-tools-pages: ['packages/dev-tools-pages']
+testnet-faucets: ['packages/testnet-faucets']
+monorepo-scripts: ['packages/monorepo-scripts']
--- a/.github/stale.yml
+++ b/.github/stale.yml
@@ -0,0 +1,19 @@
+# Number of days of inactivity before an issue becomes stale
+daysUntilStale: 30
+# Number of days of inactivity before a stale issue is closed
+daysUntilClose: 30
+# Issues with these labels will never be considered stale
+exemptLabels:
+    - pinned
+    - security
+# Label to use when marking an issue as stale
+staleLabel: stale
+# Comment to post when marking an issue as stale. Set to `false` to disable
+markComment: >
+    This issue has been automatically marked as stale because it has not had
+    recent activity. It will be closed if no further activity occurs. Thank you
+    for your contributions.
+# Comment to post when closing a stale issue. Set to `false` to disable
+closeComment: >
+    This issue has been automatically closed because no activity occured in 7 days after being marked as stale. If it's still relevant - feel free to reopen. Thank you
+    for your contributions.
--- a/.gitignore
+++ b/.gitignore
@@ -11,6 +11,10 @@ pids
 *.seed
 *.pid.lock

+# SQLite database files
+*.db
+*.sqlite
+
 # Directory for instrumented libs generated by jscoverage/JSCover
 lib-cov

@@ -79,13 +83,27 @@ packages/react-docs/example/public/bundle*
 packages/testnet-faucets/server/

 # generated contract artifacts/
-packages/contracts/generated-artifacts/
+contracts/protocol/generated-artifacts/
+contracts/multisig/generated-artifacts/
+contracts/utils/generated-artifacts/
+contracts/libs/generated-artifacts/
+contracts/interfaces/generated-artifacts/
+contracts/tokens/generated-artifacts/
+contracts/examples/generated-artifacts/
+contracts/extensions/generated-artifacts/
 packages/sol-cov/test/fixtures/artifacts/
 packages/metacoin/artifacts/

 # generated contract wrappers
 packages/abi-gen-wrappers/wrappers
-packages/contracts/generated-wrappers/
+contracts/protocol/generated-wrappers/
+contracts/multisig/generated-wrappers/
+contracts/utils/generated-wrappers/
+contracts/libs/generated-wrappers/
+contracts/interfaces/generated-wrappers/
+contracts/tokens/generated-wrappers/
+contracts/examples/generated-wrappers/
+contracts/extensions/generated-wrappers/
 packages/metacoin/src/contract_wrappers

 # solc-bin in sol-compiler
--- a/.prettierignore
+++ b/.prettierignore
@@ -1,14 +1,32 @@
 lib
 .nyc_output
-/packages/contracts/generated-wrappers
-/packages/contracts/generated-artifacts
+/contracts/protocol/generated-wrappers
+/contracts/protocol/generated-artifacts
+/contracts/multisig/generated-wrappers
+/contracts/multisig/generated-artifacts
+/contracts/utils/generated-wrappers
+/contracts/utils/generated-artifacts
+/contracts/libs/generated-wrappers
+/contracts/libs/generated-artifacts
+/contracts/interfaces/generated-wrappers
+/contracts/interfaces/generated-artifacts
+/contracts/tokens/generated-wrappers
+/contracts/tokens/generated-artifacts
+/contracts/examples/generated-wrappers
+/contracts/examples/generated-artifacts
+/contracts/extensions/generated-wrappers
+/contracts/extensions/generated-artifacts
 /packages/abi-gen-wrappers/src/generated-wrappers
 /packages/contract-artifacts/artifacts
 /python-packages/order_utils/src/zero_ex/contract_artifacts/artifacts
 /packages/json-schemas/schemas
+/python-packages/json_schemas/src/zero_ex/json_schemas/schemas
 /packages/metacoin/src/contract_wrappers
 /packages/metacoin/artifacts
 /packages/sra-spec/public/
 package.json
 scripts/postpublish_utils.js
 packages/sol-cov/test/fixtures/artifacts
+.pytest_cache
+.mypy_cache
+.tox
--- a/4
+++ b/4
@@ -14,7 +14,7 @@ packages/website/  @BMillman19 @fragosti @fabioberger @steveklebanoff
 packages/abi-gen/ @LogvinovLeon
 packages/base-contract/ @LogvinovLeon
 packages/connect/ @fragosti 
-packages/contract_templates/ @LogvinovLeon
+packages/abi-gen-templates/ @LogvinovLeon
 packages/contract-addresses/ @albrow
 packages/contract-artifacts/ @albrow
 packages/dev-utils/ @LogvinovLeon @fabioberger
@@ -32,4 +32,4 @@ packages/web3-wrapper/ @LogvinovLeon @fabioberger
 python-packages/ @feuGeneA

 # Protocol/smart contracts
-packages/contracts/test/ @albrow
+contracts/core/test/ @albrow
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -1,61 +1,105 @@
 ## 0x Contribution Guide

-Thank you for your interest in contributing to 0x protocol! We welcome contributions from anyone on the internet, and are grateful for even the smallest of fixes!
+We welcome contributions from anyone on the internet and are grateful for even the smallest contributions. This document will help get you setup to start contributing back to 0x.

-### How to contribute
+### Getting started

-If you'd like to contribute to 0x protocol, please fork the repo, fix, commit and send a pull request against the `development` branch for the maintainers to review and merge into the main code base. If you wish to submit more complex changes though, please check with a core dev first on [our RocketChat #dev channel](http://chat.0xproject.com) to ensure those changes are in-line with the general philosophy of the project and/or to get some early feedback which can make both your efforts easier as well as our review and merge procedures quick and simple.
+1.  Fork `0xproject/0x-monorepo`
+2.  Clone your fork
+3.  Follow the [installation & build steps](https://github.com/0xProject/0x-monorepo#install-dependencies) in the repo's top-level README.
+4.  Setup the recommended [Development Tooling](#development-tooling).
+5.  Open a PR with the `[WIP]` flag against the `development` branch and describe the change you are intending to undertake in the PR description. (see [our branch naming conventions](#branch-structure))

-We encourage a “PR early” approach so create the PR as early as possible even without the fix/feature ready, so that devs and other contributors know you have picked up the issue. These early PRs should indicate an 'in progress' status by adding the '[WIP]' prefix to the PR title. Please make sure your contributions adhere to our coding guidelines:
+Before removing the `[WIP]` tag and submitting the PR for review, make sure:

-*   Pull requests adding features or refactoring should be opened against the `development` branch
-*   Pull requests fixing bugs in the latest release version should be opened again the `master` branch
-*   Write [good commit messages](https://chris.beams.io/posts/git-commit/)
+*   It passes our linter checks (`yarn lint`)
+*   It is properly formatted with Prettier (`yarn prettier`)
+*   It passes our continuous integration tests (See: [Enabling code coverage checks on your fork](#enabling-code-coverage-checks-on-your-fork) for instructions on getting the `submit-coverage` test to pass on forks)
+*   You've created/updated the corresponding [CHANGELOG](#CHANGELOGs) entries.
+*   Your changes have sufficient test coverage (e.g regression tests have been added for bug fixes)

-### Code quality
+### Branch structure

-Because 0x.js is used by multiple relayers in production and their businesses depend on it, we strive for exceptional code quality. Please follow the existing code standards and conventions. `tslint` and `prettier` (described below) will help you.
+We have two main branches:

-If you're adding functionality, please also add tests and make sure they pass. We have an automatic coverage reporting tool, so we'll see it if they are missing ;)
-If you're adding a new public function/member, make sure you document it with Java doc-style comments. We use typedoc to generate [awesome documentation](https://0xproject.com/docs/0xjs) from the comments within our source code.
+*   `master` represents the most recently released (published on npm) version of the codebase.
+*   `development` represents the current development state of the codebase.

-If the sub-package you are modifying has a `CHANGELOG.md` file, make sure to add an entry in it for the change made to the package. For published packages, only changes that modify the public interface or behavior of the package need a CHANGELOG entry.
+ALL PRs should be opened against `development`.

-#### Enabling code coverage checks on your fork
+Branch names should be prefixed with `fix`, `feature` or `refactor`.

-If you simply fork the repo and then create a PR sourced from it, your PR will fail its test coverage check. This is because the 0x CircleCI configuration sets the `COVERALLS_REPO_TOKEN` environment variable to the token for 0xProject/0x-monorepo, but when running the check against your fork the token needs to match the repo that is your fork, rather than the 0x repo.
+*   e.g `fix/broken-wiki-link`
+*   If the PR only edits a single package, add it's name too
+    *   e.g `fix/website/broken-wiki-link`

-To facilitate this check, after creating your fork, but before creating the branch for your PR, do the following:
+### CHANGELOGs

-1.  Log in to [coveralls.io](https://coveralls.io/), go to Add Repos, and enable your fork. Then go to the settings for that repo, and copy the Repo Token identifier.
-2.  Log in to [CircleCI](https://circleci.com/login), go to Add Projects, click the Set Up Project button corresponding to your fork, and then click Start Building. (Aside from step 3 below, no actual set up is needed, since it will use the `.circleci/config.yml` file in 0x-monorepo, so you can ignore all of the instruction/explanation given on the page with the Start Building button.)
-3.  In CircleCI, configure your project to add an Environment Variable, with name `COVERALLS_REPO_TOKEN`, and for the value paste in the Repo Token you copied in step 1.
+At 0x we use [Semantic Versioning](http://semver.org/) for all our published packages. If a change you make corresponds to a semver bump, you must modify the package's `CHANGELOG.json` file accordingly.

-Now, when you push to your branch, CircleCI will automatically run all of the checks in your own instance, and the coverage check will work since it has the proper Repo Token, and the PR will magically refer to your own checks rather than running them in the 0x CircleCI instance.
+Each CHANGELOG entry that corresponds to a published package will have a `timestamp`. If no entry exists without a `timestamp`, you must first create a new one:

-### Styleguide
+```
+{
+        "version": "1.0.1", <- The updated package version
+        "changes": [
+            {
+                "note": "", <- Describe your change
+                "PR": 100 <- Your PR number
+            }
+        ]
+    },
+```

-We use [TSLint](https://palantir.github.io/tslint/) with [custom configs](https://github.com/0xProject/0x-monorepo/tree/development/packages/tslint-config) to keep our code style consistent.
+If an entry without a `timestamp` already exists, this means other changes have been introduced by other collaborators since the last publish. Add your changes to the list of notes and adjust the version if your PR introduces a greater semver change (i.e current changes required a patch bump, but your changes require a major version bump).

-To lint your code just run: `yarn lint`
+### Development Tooling

-We also use [Prettier](https://prettier.io/) to auto-format our code. Be sure to either add a [text editor integration](https://prettier.io/docs/en/editors.html) or a [pre-commit hook](https://prettier.io/docs/en/precommit.html) to properly format your code changes.
+We strongly recommend you use the [VSCode](https://code.visualstudio.com/) text editor since most of our code is written in Typescript and it offers amazing support for the language.
+
+#### Linter
+
+We use [TSLint](https://palantir.github.io/tslint/) with [custom configs](https://github.com/0xProject/0x-monorepo/tree/development/packages/tslint-config) to keep our code-style consistent.
+
+Use `yarn:lint` to lint the entire monorepo, and `PKG={PACKAGE_NAME} yarn lint` to lint a specific package.
+
+If you want to change a rule, or add a custom rule, please make these changes to our [tslint-config](https://github.com/0xProject/0x-monorepo/tree/development/packages/tslint-config) package. All other packages have it as a dependency.
+
+Integrate it into your text editor:
+
+*   VSCode: [vscode-tslint](https://marketplace.visualstudio.com/items?itemName=eg2.tslint)
+*   Atom: [linter-tslint](https://atom.io/packages/linter-tslint)
+
+#### Auto-formatter
+
+We use [Prettier](https://prettier.io/) to auto-format our code. Be sure to either add a [text editor integration](https://prettier.io/docs/en/editors.html) or a [pre-commit hook](https://prettier.io/docs/en/precommit.html) to properly format your code changes.

 If using the Atom text editor, we recommend you install the following packages:

-*   [atom-typescript](https://atom.io/packages/atom-typescript)
-*   [linter-tslint](https://atom.io/packages/linter-tslint)
-*   [prettier-atom](https://atom.io/packages/prettier-atom)
-*   [language-ethereum](https://atom.io/packages/language-ethereum)
+*   VSCode: [prettier-vscode](https://marketplace.visualstudio.com/items?itemName=esbenp.prettier-vscode)
+*   Atom: [prettier-atom](https://atom.io/packages/prettier-atom)

-Our CI will also run TSLint and Prettier as a part of the test run when you submit your PR. Make sure that the CI tests pass for your contribution.
+## Unenforced coding conventions

-### Branch structure & versioning
+A few of our coding conventions are not yet enforced by the linter/auto-formatter. Be careful to follow these conventions in your PR's.

-We use [semantic versioning](http://semver.org/), but before a package reaches v1.0.0 all breaking changes as well as new features will be minor version bumps.
+1.  Unused anonymous function parameters should be named with an underscore + number (e.g \_1, \_2, etc...)
+1.  There should be a new-line between methods in a class and between test cases.
+1.  If a string literal has the same value in two or more places, it should be a single constant referenced in both places.
+1.  Do not import from a project's `index.ts` (e.g import { Token } from '../src';). Always import from the source file itself.
+1.  Generic error variables should be named `err` instead of `e` or `error`.
+1.  If you _must_ cast a variable to any - try to type it back as fast as possible. (e.g., `const cw = ((zeroEx as any)._contractWrappers as ContractWrappers);`). This ensures subsequent code is type-safe.
+1.  Our enum conventions coincide with the recommended Typescript conventions, using capitalized keys, and all-caps snake-case values. Eg `GetStats = 'GET_STATS'`
+1.  All public, exported methods/functions/classes must have associated Javadoc-style comments.

-We have two main branches: `master` and `development`.
+### Fix `submit-coverage` CI failure

-`master` represents the most recent released (published on npm) version.
+If you simply fork the repo and then create a PR from it, your PR will fail the `submit-coverage` check on CI. This is because the 0x CircleCI configuration sets the `COVERALLS_REPO_TOKEN` environment variable to the token for `0xProject/0x-monorepo`, but when running the check against your fork the token needs to match your repo's name `your-username/0x-monorepo`.

-`development` represents the development state and is a default branch to which you will submit a PR. We use this structure so that we can push hotfixes to the currently released version without needing to publish all the changes made towards the next release. If a hotfix is implemented on `master`, it is back-ported to `development`.
+To facilitate this check, after creating your fork, but before creating the branch for your PR, do the following:
+
+1.  Log in to [coveralls.io](https://coveralls.io/), go to `Add Repos`, and enable your fork. Then go to the settings for that repo, and copy the `Repo Token` identifier.
+2.  Log in to [CircleCI](https://circleci.com/login), go to `Add Projects`, click the `Set Up Project` button corresponding to your fork, and then click `Start Building`. (Aside from step 3 below, no actual set up is needed, since it will use the `.circleci/config.yml` file in 0x-monorepo, so you can ignore all of the instruction/explanation given on the page with the `Start Building` button.)
+3.  In CircleCI, configure your project to add an environment variable, with name `COVERALLS_REPO_TOKEN`, and for the value paste in the `Repo Token` you copied in step 1.
+
+Now, when you push to your branch, CircleCI will automatically run all of the checks in your own instance, and the coverage check will work since it has the proper `Repo Token`, and the PR will magically refer to your own checks rather than running them in the 0x CircleCI instance.
--- a/ISSUE_TEMPLATE.md
+++ b/ISSUE_TEMPLATE.md
@@ -46,10 +46,14 @@

 <!--- Include as many relevant details about the environment you experienced the bug in -->

-|             Package | Version |
-| ------------------: | :------ |
-|             `0x.js` | 0.25.0  |
-| `Exchange Contract` | v1      |
+| Package | Version |
+| ------: | :------ |
+
+
+<!-- For example:
+|             `0x.js` | 2.0.4   |
+| `Exchange Contract` | v2      |
+-->

 | Network |
 | ------- |
--- a/4
+++ b/4
@@ -1,4 +1,4 @@
-Copyright 2017 ZeroEx Inc.
+Copyright 2017 ZeroEx Intl.

 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -10,4 +10,4 @@ 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.
+limitations under the License.
--- a/PULL_REQUEST_TEMPLATE.md
+++ b/PULL_REQUEST_TEMPLATE.md
@@ -21,7 +21,6 @@
 <!--- The following points should be used to indicate the progress of your PR.  Put an `x` in all the boxes that apply right now, and come back over time and check them off as you make progress.  If you're unsure about any of these, don't hesitate to ask. We're here to help! -->

 *   [ ] Prefix PR title with `[WIP]` if necessary.
-*   [ ] Prefix PR title with bracketed package name(s) corresponding to the changed package(s). For example: `[sol-cov] Fixed bug`.
 *   [ ] Add tests to cover changes as needed.
 *   [ ] Update documentation as needed.
 *   [ ] Add new entries to the relevant CHANGELOG.jsons.
--- a/README.md
+++ b/README.md
@@ -1,8 +1,8 @@
-<img src="https://github.com/0xProject/branding/blob/master/0x_Black_CMYK.png" width="200px" >
+<img src="https://github.com/0xProject/branding/blob/master/0x%20Logo/PNG/0x-Logo-Black.png" width="150px" >

 ---

-[0x][website-url] is an open protocol that facilitates trustless, low friction exchange of Ethereum-based assets. A full description of the protocol may be found in our [whitepaper][whitepaper-url].
+[0x][website-url] is an open protocol that facilitates trustless, low friction exchange of Ethereum-based assets. For more information on how it works, check out the [0x protocol specification](https://github.com/0xProject/0x-protocol-specification/blob/master/v2/v2-specification.md).

 This repository is a monorepo including the 0x protocol smart contracts and numerous developer tools. Each public sub-package is independently published to NPM.

@@ -18,63 +18,75 @@ If you're developing on 0x now or are interested in using 0x infrastructure in t
 [![Join the chat at https://gitter.im/0xProject/Lobby](https://badges.gitter.im/0xProject/Lobby.svg)](https://gitter.im/0xProject/Lobby?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 [![License](https://img.shields.io/badge/License-Apache%202.0-blue.svg)](https://opensource.org/licenses/Apache-2.0)

-### Published Packages
+## Packages

-| Package                                                  | Version                                                                                                                 | Description                                                                                                              |
-| -------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------ |
-| [`0x.js`](/packages/0x.js)                               | [![npm](https://img.shields.io/npm/v/0x.js.svg)](https://www.npmjs.com/package/0x.js)                                   | A Javascript library for interacting with the 0x protocol                                                                |
-| [`@0x/abi-gen`](/packages/abi-gen)                       | [![npm](https://img.shields.io/npm/v/@0x/abi-gen.svg)](https://www.npmjs.com/package/@0x/abi-gen)                       | Tool to generate TS wrappers from smart contract ABIs                                                                    |
-| [`@0x/abi-gen-wrappers`](/packages/abi-gen-wrappers)     | [![npm](https://img.shields.io/npm/v/@0x/abi-gen-wrappers.svg)](https://www.npmjs.com/package/@0x/abi-gen-wrappers)     | Low-level 0x smart contract wrappers generated using @0x/abi-gen                                                         |
-| [`@0x/assert`](/packages/assert)                         | [![npm](https://img.shields.io/npm/v/@0x/assert.svg)](https://www.npmjs.com/package/@0x/assert)                         | Type and schema assertions used by our packages                                                                          |
-| [`@0x/asset-buyer`](/packages/asset-buyer)               | [![npm](https://img.shields.io/npm/v/@0x/asset-buyer.svg)](https://www.npmjs.com/package/@0x/asset-buyer)               | Convenience package for discovering and buying assets with Ether                                                         |
-| [`@0x/base-contract`](/packages/base-contract)           | [![npm](https://img.shields.io/npm/v/@0x/base-contract.svg)](https://www.npmjs.com/package/@0x/base-contract)           | BaseContract used by auto-generated `abi-gen` wrapper contracts                                                          |
-| [`@0x/connect`](/packages/connect)                       | [![npm](https://img.shields.io/npm/v/@0x/connect.svg)](https://www.npmjs.com/package/@0x/connect)                       | A Javascript library for interacting with the Standard Relayer API                                                       |
-| [`@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) | Used to get known addresses of deployed 0x contracts                                                                     |
-| [`@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-wrappers`](/packages/contract-wrappers)   | [![npm](https://img.shields.io/npm/v/@0x/contract-wrappers.svg)](https://www.npmjs.com/package/@0x/contract-wrappers)   | Smart TS wrappers for 0x smart contracts                                                                                 |
-| [`@0x/dev-utils`](/packages/dev-utils)                   | [![npm](https://img.shields.io/npm/v/@0x/dev-utils.svg)](https://www.npmjs.com/package/@0x/dev-utils)                   | Dev utils to be shared across 0x projects and packages                                                                   |
-| [`@0x/fill-scenarios`](/packages/fill-scenarios)         | [![npm](https://img.shields.io/npm/v/@0x/fill-scenarios.svg)](https://www.npmjs.com/package/@0x/fill-scenarios)         | 0x order fill scenario generation                                                                                        |
-| [`@0x/json-schemas`](/packages/json-schemas)             | [![npm](https://img.shields.io/npm/v/@0x/json-schemas.svg)](https://www.npmjs.com/package/@0x/json-schemas)             | 0x-related json schemas                                                                                                  |
-| [`@0x/migrations`](/packages/migrations)                 | [![npm](https://img.shields.io/npm/v/@0x/migrations.svg)](https://www.npmjs.com/package/@0x/migrations)                 | 0x smart contract migrations                                                                                             |
-| [`@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/order-watcher`](/packages/order-watcher)           | [![npm](https://img.shields.io/npm/v/@0x/order-watcher.svg)](https://www.npmjs.com/package/@0x/order-watcher)           | An order watcher daemon that watches for order validity                                                                  |
-| [`@0x/react-docs`](/packages/react-docs)                 | [![npm](https://img.shields.io/npm/v/@0x/react-docs.svg)](https://www.npmjs.com/package/@0x/react-docs)                 | React documentation component for rendering TypeDoc & Doxity generated JSON                                              |
-| [`@0x/react-shared`](/packages/react-shared)             | [![npm](https://img.shields.io/npm/v/@0x/react-shared.svg)](https://www.npmjs.com/package/@0x/react-shared)             | 0x shared react components                                                                                               |
-| [`@0x/sol-compiler`](/packages/sol-compiler)             | [![npm](https://img.shields.io/npm/v/@0x/sol-compiler.svg)](https://www.npmjs.com/package/@0x/sol-compiler)             | A thin wrapper around Solc.js that outputs artifacts, resolves imports, only re-compiles when needed, and other niceties |
-| [`@0x/sol-cov`](/packages/sol-cov)                       | [![npm](https://img.shields.io/npm/v/@0x/sol-cov.svg)](https://www.npmjs.com/package/@0x/sol-cov)                       | Solidity test coverage tool                                                                                              |
-| [`@0x/sol-doc`](/packages/sol-doc)                       | [![npm](https://img.shields.io/npm/v/@0x/sol-doc.svg)](https://www.npmjs.com/package/@0x/sol-doc)                       | Solidity documentation generator                                                                                         |
-| [`@0x/sol-resolver`](/packages/sol-resolver)             | [![npm](https://img.shields.io/npm/v/@0x/sol-resolver.svg)](https://www.npmjs.com/package/@0x/sol-resolver)             | Import resolver for smart contracts dependencies                                                                         |
-| [`@0x/sra-spec`](/packages/sra-spec)                     | [![npm](https://img.shields.io/npm/v/@0x/sra-spec.svg)](https://www.npmjs.com/package/@0x/sra-spec)                     | OpenAPI specification for the standard relayer API                                                                       |
-| [`@0x/subproviders`](/packages/subproviders)             | [![npm](https://img.shields.io/npm/v/@0x/subproviders.svg)](https://www.npmjs.com/package/@0x/subproviders)             | Useful web3 subproviders (e.g. LedgerSubprovider)                                                                        |
-| [`@0x/tslint-config`](/packages/tslint-config)           | [![npm](https://img.shields.io/npm/v/@0x/tslint-config.svg)](https://www.npmjs.com/package/@0x/tslint-config)           | Custom 0x development TSLint rules                                                                                       |
-| [`@0x/types`](/packages/types)                           | [![npm](https://img.shields.io/npm/v/@0x/types.svg)](https://www.npmjs.com/package/@0x/types)                           | Shared type declarations                                                                                                 |
-| [`@0x/typescript-typings`](/packages/typescript-typings) | [![npm](https://img.shields.io/npm/v/@0x/typescript-typings.svg)](https://www.npmjs.com/package/@0x/typescript-typings) | Repository of types for external packages                                                                                |
-| [`@0x/utils`](/packages/utils)                           | [![npm](https://img.shields.io/npm/v/@0x/utils.svg)](https://www.npmjs.com/package/@0x/utils)                           | Shared utilities                                                                                                         |
-| [`@0x/web3-wrapper`](/packages/web3-wrapper)             | [![npm](https://img.shields.io/npm/v/@0x/web3-wrapper.svg)](https://www.npmjs.com/package/@0x/web3-wrapper)             | Web3 wrapper                                                                                                             |
+Visit our [developer portal](https://0xproject.com/docs/order-utils) for a comprehensive list of core & community maintained packages. All packages maintained with this monorepo are listed below.

-### Private Packages
+### Python Packages

-| Package                                                  | Description                                                      |
-| -------------------------------------------------------- | ---------------------------------------------------------------- |
-| [`@0x/contracts`](/packages/contracts)                   | 0x solidity smart contracts & tests                              |
-| [`@0x/react-docs-example`](/packages/react-docs-example) | Example documentation site created with `@0x/react-docs`         |
-| [`@0x/testnet-faucets`](/packages/testnet-faucets)       | A faucet micro-service that dispenses test ERC20 tokens or Ether |
-| [`@0x/website`](/packages/website)                       | 0x website & Portal DApp                                         |
+| Package                                            | Version                                                                                                 | Description                                                                                       |
+| -------------------------------------------------- | ------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------- |
+| [`0x-json-schemas`](/python-packages/json_schemas) | [![PyPI](https://img.shields.io/pypi/v/0x-json-schemas.svg)](https://pypi.org/project/0x-json-schemas/) | 0x-related JSON schemas                                                                           |
+| [`0x-order-utils`](/python-packages/order_utils)   | [![PyPI](https://img.shields.io/pypi/v/0x-order-utils.svg)](https://pypi.org/project/0x-order-utils/)   | A set of utilities for generating, parsing, signing and validating 0x orders                      |
+| [`0x-sra-client`](/python-packages/sra_client)     | [![PyPI](https://img.shields.io/pypi/v/0x-sra-client.svg)](https://pypi.org/project/0x-sra-client/)     | A Python client for interacting with servers conforming to the Standard Relayer API specification |
+
+### Typescript/Javascript Packages
+
+#### 0x-specific packages
+
+| Package                                                  | Version                                                                                                                 | Description                                                                                       |
+| -------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------- |
+| [`0x.js`](/packages/0x.js)                               | [![npm](https://img.shields.io/npm/v/0x.js.svg)](https://www.npmjs.com/package/0x.js)                                   | An aggregate package combining many smaller utility packages for interacting with the 0x protocol |
+| [`@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/json-schemas`](/packages/json-schemas)             | [![npm](https://img.shields.io/npm/v/@0x/json-schemas.svg)](https://www.npmjs.com/package/@0x/json-schemas)             | 0x-related JSON schemas                                                                           |
+| [`@0x/order-watcher`](/packages/order-watcher)           | [![npm](https://img.shields.io/npm/v/@0x/order-watcher.svg)](https://www.npmjs.com/package/@0x/order-watcher)           | An order watcher daemon that watches for order validity                                           |
+| [`@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/abi-gen-wrappers`](/packages/abi-gen-wrappers)     | [![npm](https://img.shields.io/npm/v/@0x/abi-gen-wrappers.svg)](https://www.npmjs.com/package/@0x/abi-gen-wrappers)     | Low-level 0x smart contract wrappers generated using `@0x/abi-gen`                                |
+| [`@0x/sra-spec`](/packages/sra-spec)                     | [![npm](https://img.shields.io/npm/v/@0x/sra-spec.svg)](https://www.npmjs.com/package/@0x/sra-spec)                     | OpenAPI specification for the Standard Relayer API                                                |
+| [`@0x/connect`](/packages/connect)                       | [![npm](https://img.shields.io/npm/v/@0x/connect.svg)](https://www.npmjs.com/package/@0x/connect)                       | An HTTP/WS client for interacting with the Standard Relayer API                                   |
+| [`@0x/asset-buyer`](/packages/asset-buyer)               | [![npm](https://img.shields.io/npm/v/@0x/asset-buyer.svg)](https://www.npmjs.com/package/@0x/asset-buyer)               | Convenience package for discovering and buying assets with Ether                                  |
+
+#### Ethereum tooling
+
+| Package                                      | Version                                                                                                     | Description                                                                                                                                                                             |
+| -------------------------------------------- | ----------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| [`@0x/web3-wrapper`](/packages/web3-wrapper) | [![npm](https://img.shields.io/npm/v/@0x/web3-wrapper.svg)](https://www.npmjs.com/package/@0x/web3-wrapper) | An Ethereum JSON RPC client                                                                                                                                                             |
+| [`@0x/sol-compiler`](/packages/sol-compiler) | [![npm](https://img.shields.io/npm/v/@0x/sol-compiler.svg)](https://www.npmjs.com/package/@0x/sol-compiler) | A wrapper around solc-js that adds smart re-compilation, ability to compile an entire project, Solidity version specific compilation, standard input description support and much more. |
+| [`@0x/sol-cov`](/packages/sol-cov)           | [![npm](https://img.shields.io/npm/v/@0x/sol-cov.svg)](https://www.npmjs.com/package/@0x/sol-cov)           | A solidity test coverage tool                                                                                                                                                           |
+| [`@0x/sol-resolver`](/packages/sol-resolver) | [![npm](https://img.shields.io/npm/v/@0x/sol-resolver.svg)](https://www.npmjs.com/package/@0x/sol-resolver) | Import resolver for smart contracts dependencies                                                                                                                                        |
+| [`@0x/subproviders`](/packages/subproviders) | [![npm](https://img.shields.io/npm/v/@0x/subproviders.svg)](https://www.npmjs.com/package/@0x/subproviders) | Web3 provider middlewares (e.g. LedgerSubprovider)                                                                                                                                      |
+| [`@0x/sol-doc`](/packages/sol-doc)           | [![npm](https://img.shields.io/npm/v/@0x/sol-doc.svg)](https://www.npmjs.com/package/@0x/sol-doc)           | Solidity documentation generator                                                                                                                                                        |
+
+#### Utilities
+
+| Package                                                  | Version                                                                                                                 | Description                                                                  |
+| -------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------- |
+| [`@0x/abi-gen`](/packages/abi-gen)                       | [![npm](https://img.shields.io/npm/v/@0x/abi-gen.svg)](https://www.npmjs.com/package/@0x/abi-gen)                       | Tool to generate TS wrappers from smart contract ABIs                        |
+| [`@0x/tslint-config`](/packages/tslint-config)           | [![npm](https://img.shields.io/npm/v/@0x/tslint-config.svg)](https://www.npmjs.com/package/@0x/tslint-config)           | Custom TSLint rules used by the 0x core team                                 |
+| [`@0x/types`](/packages/types)                           | [![npm](https://img.shields.io/npm/v/@0x/types.svg)](https://www.npmjs.com/package/@0x/types)                           | Shared type declarations                                                     |
+| [`@0x/typescript-typings`](/packages/typescript-typings) | [![npm](https://img.shields.io/npm/v/@0x/typescript-typings.svg)](https://www.npmjs.com/package/@0x/typescript-typings) | Repository of types for external packages                                    |
+| [`@0x/utils`](/packages/utils)                           | [![npm](https://img.shields.io/npm/v/@0x/utils.svg)](https://www.npmjs.com/package/@0x/utils)                           | Shared utilities                                                             |
+| [`@0x/react-docs`](/packages/react-docs)                 | [![npm](https://img.shields.io/npm/v/@0x/react-docs.svg)](https://www.npmjs.com/package/@0x/react-docs)                 | React documentation component for rendering TypeDoc & sol-doc generated JSON |
+| [`@0x/react-shared`](/packages/react-shared)             | [![npm](https://img.shields.io/npm/v/@0x/react-shared.svg)](https://www.npmjs.com/package/@0x/react-shared)             | 0x shared react components                                                   |
+| [`@0x/assert`](/packages/assert)                         | [![npm](https://img.shields.io/npm/v/@0x/assert.svg)](https://www.npmjs.com/package/@0x/assert)                         | Type and schema assertions used by our packages                              |
+| [`@0x/base-contract`](/packages/base-contract)           | [![npm](https://img.shields.io/npm/v/@0x/base-contract.svg)](https://www.npmjs.com/package/@0x/base-contract)           | BaseContract used by auto-generated `abi-gen` wrapper contracts              |
+| [`@0x/dev-utils`](/packages/dev-utils)                   | [![npm](https://img.shields.io/npm/v/@0x/dev-utils.svg)](https://www.npmjs.com/package/@0x/dev-utils)                   | Dev utils to be shared across 0x packages                                    |
+| [`@0x/fill-scenarios`](/packages/fill-scenarios)         | [![npm](https://img.shields.io/npm/v/@0x/fill-scenarios.svg)](https://www.npmjs.com/package/@0x/fill-scenarios)         | 0x order fill scenario generator                                             |
+
+#### Private Packages
+
+| Package                                            | Description                                                                      |
+| -------------------------------------------------- | -------------------------------------------------------------------------------- |
+| [`@0x/contracts`](/contracts/core)                 | 0x protocol solidity smart contracts & tests                                     |
+| [`@0x/instant`](/packages/instant)                 | A free and flexible way to offer simple crypto purchasing in any app or website. |
+| [`@0x/testnet-faucets`](/packages/testnet-faucets) | A faucet micro-service that dispenses test ERC20 tokens or Ether                 |
+| [`@0x/website`](/packages/website)                 | 0x website                                                                       |

 ## Usage

-Dedicated documentation pages:
-
-*   [0x.js Library](https://0xproject.com/docs/0xjs)
-*   [0x Connect](https://0xproject.com/docs/connect)
-*   [Smart contracts](https://0xproject.com/docs/contracts)
-*   [Subproviders](https://0xproject.com/docs/subproviders)
-*   [Sol Compiler](https://0xproject.com/docs/sol-compiler)
-*   [Web3-wrapper](https://0xproject.com/docs/web3-wrapper)
-*   [JSON-schemas](https://0xproject.com/docs/json-schemas)
-*   [Sol-cov](https://0xproject.com/docs/sol-cov)
-*   [Standard Relayer API](https://github.com/0xProject/standard-relayer-api/blob/master/README.md)
-
 Node version >= 6.12 is required.

 Most of the packages require additional typings for external dependencies.
--- a/packages/contracts/.solhint.json
+++ b/packages/contracts/.solhint.json
@@ -5,6 +5,7 @@
        "avoid-tx-origin": "warn",
        "bracket-align": false,
        "code-complexity": false,
+        "compiler-fixed": false,
        "const-name-snakecase": "error",
        "expression-indent": "error",
        "function-max-lines": false,
--- a/contracts/TESTING.md
+++ b/contracts/TESTING.md
@@ -0,0 +1,48 @@
+# Contracts testing options
+
+## Revert stack traces
+
+If you want to see helpful stack traces (incl. line number, code snippet) for smart contract reverts, run the tests with:
+
+```
+yarn test:trace
+```
+
+**Note:** This currently slows down the test runs and is therefore not enabled by default.
+
+## Backing Ethereum node
+
+By default, our tests run against an in-process [Ganache](https://github.com/trufflesuite/ganache-core) instance. In order to run the tests against [Geth](https://github.com/ethereum/go-ethereum), first follow the instructions in the README for the devnet package to start the devnet Geth node. Then run:
+
+```bash
+TEST_PROVIDER=geth yarn test
+```
+
+## Code coverage
+
+In order to see the Solidity code coverage output generated by `@0x/sol-cov`, run:
+
+```
+yarn test:coverage
+```
+
+## Gas profiler
+
+In order to profile the gas costs for a specific smart contract call/transaction, you can run the tests in `profiler` mode.
+
+**Note:** Traces emitted by ganache have incorrect gas costs so we recommend using Geth for profiling.
+
+```
+TEST_PROVIDER=geth yarn test:profiler
+```
+
+You'll see a warning that you need to explicitly enable and disable the profiler before and after the block of code you want to profile.
+
+```typescript
+import { profiler } from './utils/profiler';
+profiler.start();
+// Some call to a smart contract
+profiler.stop();
+```
+
+Without explicitly starting and stopping the profiler, the profiler output will be too busy, and therefore unusable.
--- a/contracts/examples/CHANGELOG.json
+++ b/contracts/examples/CHANGELOG.json
@@ -0,0 +1,20 @@
+[
+    {
+        "timestamp": 1547040760,
+        "version": "1.0.3",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1544741676,
+        "version": "1.0.2",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    }
+]
--- a/contracts/examples/CHANGELOG.md
+++ b/contracts/examples/CHANGELOG.md
@@ -0,0 +1,14 @@
+<!--
+changelogUtils.file is auto-generated using the monorepo-scripts package. Don't edit directly.
+Edit the package's CHANGELOG.json file only.
+-->
+
+CHANGELOG
+
+## v1.0.3 - _January 9, 2019_
+
+    * Dependencies updated
+
+## v1.0.2 - _December 13, 2018_
+
+    * Dependencies updated
--- a/contracts/examples/README.md
+++ b/contracts/examples/README.md
@@ -0,0 +1,56 @@
+## Contract examples
+
+Example smart contracts that interact with 0x protocol.
+
+## Usage
+
+Contracts can be found in the [contracts](./contracts) directory.
+This package contains example implementations of contracts that interact with the protocol but are _not_ intended for use in production. Examples include [filter](https://github.com/0xProject/0x-protocol-specification/blob/master/v2/v2-specification.md#filter-contracts) contracts, a [Wallet](https://github.com/0xProject/0x-protocol-specification/blob/master/v2/v2-specification.md#wallet) contract, and a [Validator](https://github.com/0xProject/0x-protocol-specification/blob/master/v2/v2-specification.md#validator) contract, among others.
+
+## Contributing
+
+We strongly recommend that the community help us make improvements and determine the future direction of the protocol. To report bugs within this package, please create an issue in this repository.
+
+For proposals regarding the 0x protocol's smart contract architecture, message format, or additional functionality, go to the [0x Improvement Proposals (ZEIPs)](https://github.com/0xProject/ZEIPs) repository and follow the contribution guidelines provided therein.
+
+Please read our [contribution guidelines](../../CONTRIBUTING.md) before getting started.
+
+### Install Dependencies
+
+If you don't have yarn workspaces enabled (Yarn < v1.0) - enable them:
+
+```bash
+yarn config set workspaces-experimental true
+```
+
+Then install dependencies
+
+```bash
+yarn install
+```
+
+### Build
+
+To build this package and all other monorepo packages that it depends on, run the following from the monorepo root directory:
+
+```bash
+PKG=@0x/contracts-examples yarn build
+```
+
+Or continuously rebuild on change:
+
+```bash
+PKG=@0x/contracts-examples yarn watch
+```
+
+### Clean
+
+```bash
+yarn clean
+```
+
+### Lint
+
+```bash
+yarn lint
+```
--- a/contracts/examples/compiler.json
+++ b/contracts/examples/compiler.json
@@ -0,0 +1,22 @@
+{
+    "artifactsDir": "./generated-artifacts",
+    "contractsDir": "./contracts",
+    "compilerSettings": {
+        "optimizer": {
+            "enabled": true,
+            "runs": 1000000
+        },
+        "outputSelection": {
+            "*": {
+                "*": [
+                    "abi",
+                    "evm.bytecode.object",
+                    "evm.bytecode.sourceMap",
+                    "evm.deployedBytecode.object",
+                    "evm.deployedBytecode.sourceMap"
+                ]
+            }
+        }
+    },
+    "contracts": ["ExchangeWrapper", "Validator", "Wallet", "Whitelist"]
+}
--- a/packages/contracts/contracts/examples/ExchangeWrapper/ExchangeWrapper.sol
+++ b/packages/contracts/contracts/examples/ExchangeWrapper/ExchangeWrapper.sol
@@ -19,8 +19,8 @@
 pragma solidity 0.4.24;
 pragma experimental ABIEncoderV2;

-import "../../protocol/Exchange/interfaces/IExchange.sol";
-import "../../protocol/Exchange/libs/LibOrder.sol";
+import "@0x/contracts-interfaces/contracts/protocol/Exchange/IExchange.sol";
+import "@0x/contracts-libs/contracts/libs/LibOrder.sol";


 contract ExchangeWrapper {
--- a/packages/contracts/contracts/examples/Validator/Validator.sol
+++ b/packages/contracts/contracts/examples/Validator/Validator.sol
@@ -18,7 +18,7 @@

 pragma solidity 0.4.24;

-import "../../protocol/Exchange/interfaces/IValidator.sol";
+import "@0x/contracts-interfaces/contracts/protocol/Exchange/IValidator.sol";


 contract Validator is 
--- a/packages/contracts/contracts/examples/Wallet/Wallet.sol
+++ b/packages/contracts/contracts/examples/Wallet/Wallet.sol
@@ -18,8 +18,8 @@

 pragma solidity 0.4.24;

-import "../../protocol/Exchange/interfaces/IWallet.sol";
-import "../../utils/LibBytes/LibBytes.sol";
+import "@0x/contracts-interfaces/contracts/protocol/Exchange/IWallet.sol";
+import "@0x/contracts-utils/contracts/utils/LibBytes/LibBytes.sol";


 contract Wallet is 
--- a/packages/contracts/contracts/examples/Whitelist/Whitelist.sol
+++ b/packages/contracts/contracts/examples/Whitelist/Whitelist.sol
@@ -19,9 +19,9 @@
 pragma solidity 0.4.24;
 pragma experimental ABIEncoderV2;

-import "../../protocol/Exchange/interfaces/IExchange.sol";
-import "../../protocol/Exchange/libs/LibOrder.sol";
-import "../../utils/Ownable/Ownable.sol";
+import "@0x/contracts-interfaces/contracts/protocol/Exchange/IExchange.sol";
+import "@0x/contracts-libs/contracts/libs/LibOrder.sol";
+import "@0x/contracts-utils/contracts/utils/Ownable/Ownable.sol";


 contract Whitelist is
--- a/contracts/examples/package.json
+++ b/contracts/examples/package.json
@@ -0,0 +1,82 @@
+{
+    "name": "@0x/contracts-examples",
+    "version": "1.0.3",
+    "engines": {
+        "node": ">=6.12"
+    },
+    "description": "Smart contract examples of 0x protocol",
+    "main": "lib/src/index.js",
+    "directories": {
+        "test": "test"
+    },
+    "scripts": {
+        "build": "yarn pre_build && tsc -b",
+        "build:ci": "yarn build",
+        "pre_build": "run-s compile generate_contract_wrappers",
+        "compile": "sol-compiler",
+        "watch": "sol-compiler -w",
+        "clean": "shx rm -rf lib generated-artifacts generated-wrappers",
+        "generate_contract_wrappers": "abi-gen --abis  ${npm_package_config_abis} --template ../../node_modules/@0x/abi-gen-templates/contract.handlebars --partials '../../node_modules/@0x/abi-gen-templates/partials/**/*.handlebars' --output generated-wrappers --backend ethers",
+        "lint": "tslint --format stylish --project . --exclude ./generated-wrappers/**/* --exclude ./generated-artifacts/**/* --exclude **/lib/**/* && yarn lint-contracts",
+        "lint-contracts": "solhint -c ../.solhint.json contracts/**/**/**/**/*.sol"
+    },
+    "config": {
+        "abis": "generated-artifacts/@(ExchangeWrapper|Validator|Wallet|Whitelist).json"
+    },
+    "repository": {
+        "type": "git",
+        "url": "https://github.com/0xProject/0x-monorepo.git"
+    },
+    "license": "Apache-2.0",
+    "bugs": {
+        "url": "https://github.com/0xProject/0x-monorepo/issues"
+    },
+    "homepage": "https://github.com/0xProject/0x-monorepo/contracts/examples/README.md",
+    "devDependencies": {
+        "@0x/abi-gen": "^1.0.20",
+        "@0x/contracts-test-utils": "^1.0.3",
+        "@0x/dev-utils": "^1.0.22",
+        "@0x/sol-compiler": "^2.0.0",
+        "@0x/sol-cov": "^2.1.17",
+        "@0x/subproviders": "^2.1.9",
+        "@0x/tslint-config": "^2.0.0",
+        "@types/bn.js": "^4.11.0",
+        "@types/lodash": "4.14.104",
+        "@types/node": "*",
+        "@types/yargs": "^10.0.0",
+        "chai": "^4.0.1",
+        "chai-as-promised": "^7.1.0",
+        "chai-bignumber": "^2.0.1",
+        "dirty-chai": "^2.0.1",
+        "ethereumjs-abi": "0.6.5",
+        "make-promises-safe": "^1.1.0",
+        "mocha": "^4.1.0",
+        "npm-run-all": "^4.1.2",
+        "shx": "^0.2.2",
+        "solhint": "^1.4.1",
+        "tslint": "5.11.0",
+        "typescript": "3.0.1",
+        "yargs": "^10.0.3"
+    },
+    "dependencies": {
+        "@0x/base-contract": "^3.0.11",
+        "@0x/contracts-interfaces": "^1.0.3",
+        "@0x/contracts-libs": "^1.0.3",
+        "@0x/contracts-multisig": "^1.0.3",
+        "@0x/contracts-tokens": "^1.0.3",
+        "@0x/contracts-utils": "^1.0.3",
+        "@0x/order-utils": "^3.1.0",
+        "@0x/types": "^1.5.0",
+        "@0x/typescript-typings": "^3.0.6",
+        "@0x/utils": "^2.1.1",
+        "@0x/web3-wrapper": "^3.2.2",
+        "@types/js-combinatorics": "^0.5.29",
+        "bn.js": "^4.11.8",
+        "ethereum-types": "^1.1.4",
+        "ethereumjs-util": "^5.1.1",
+        "lodash": "^4.17.5"
+    },
+    "publishConfig": {
+        "access": "public"
+    }
+}
--- a/contracts/examples/src/artifacts/index.ts
+++ b/contracts/examples/src/artifacts/index.ts
@@ -0,0 +1,13 @@
+import { ContractArtifact } from 'ethereum-types';
+
+import * as ExchangeWrapper from '../../generated-artifacts/ExchangeWrapper.json';
+import * as Validator from '../../generated-artifacts/Validator.json';
+import * as Wallet from '../../generated-artifacts/Wallet.json';
+import * as Whitelist from '../../generated-artifacts/Whitelist.json';
+
+export const artifacts = {
+    ExchangeWrapper: ExchangeWrapper as ContractArtifact,
+    Validator: Validator as ContractArtifact,
+    Wallet: Wallet as ContractArtifact,
+    Whitelist: Whitelist as ContractArtifact,
+};
--- a/contracts/examples/src/index.ts
+++ b/contracts/examples/src/index.ts
@@ -0,0 +1,2 @@
+export * from './artifacts';
+export * from './wrappers';
--- a/contracts/examples/src/wrappers/index.ts
+++ b/contracts/examples/src/wrappers/index.ts
@@ -0,0 +1,4 @@
+export * from '../../generated-wrappers/exchange_wrapper';
+export * from '../../generated-wrappers/validator';
+export * from '../../generated-wrappers/wallet';
+export * from '../../generated-wrappers/whitelist';
--- a/contracts/examples/tsconfig.json
+++ b/contracts/examples/tsconfig.json
@@ -0,0 +1,16 @@
+{
+    "extends": "../../tsconfig",
+    "compilerOptions": {
+        "outDir": "lib",
+        "rootDir": ".",
+        "resolveJsonModule": true
+    },
+    "include": ["./src/**/*", "./test/**/*", "./generated-wrappers/**/*"],
+    "files": [
+        "./generated-artifacts/ExchangeWrapper.json",
+        "./generated-artifacts/Validator.json",
+        "./generated-artifacts/Wallet.json",
+        "./generated-artifacts/Whitelist.json"
+    ],
+    "exclude": ["./deploy/solc/solc_bin"]
+}
--- a/contracts/examples/tslint.json
+++ b/contracts/examples/tslint.json
--- a/contracts/extensions/CHANGELOG.json
+++ b/contracts/extensions/CHANGELOG.json
@@ -0,0 +1,38 @@
+[
+    {
+        "version": "1.2.0",
+        "changes": [
+            {
+                "note": "Added Dutch Auction Wrapper",
+                "pr": 1465
+            }
+        ],
+        "timestamp": 1547040760
+    },
+    {
+        "version": "1.1.0",
+        "changes": [
+            {
+                "note": "Added Balance Threshold Filter",
+                "pr": 1383
+            },
+            {
+                "note": "Add OrderMatcher",
+                "pr": 1117
+            },
+            {
+                "note": "Add OrderValidator",
+                "pr": 1464
+            }
+        ]
+    },
+    {
+        "timestamp": 1544741676,
+        "version": "1.0.2",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    }
+]
--- a/contracts/extensions/CHANGELOG.md
+++ b/contracts/extensions/CHANGELOG.md
@@ -0,0 +1,20 @@
+<!--
+changelogUtils.file is auto-generated using the monorepo-scripts package. Don't edit directly.
+Edit the package's CHANGELOG.json file only.
+-->
+
+CHANGELOG
+
+## v1.2.0 - _January 9, 2019_
+
+    * Added Dutch Auction Wrapper (#1465)
+
+## v1.1.0 - _Invalid date_
+
+    * Added Balance Threshold Filter (#1383)
+    * Add OrderMatcher (#1117)
+    * Add OrderValidator (#1464)
+
+## v1.0.2 - _December 13, 2018_
+
+    * Dependencies updated
--- a/contracts/extensions/DEPLOYS.json
+++ b/contracts/extensions/DEPLOYS.json
@@ -0,0 +1,31 @@
+[
+    {
+        "name": "Forwarder",
+        "version": "1.1.0",
+        "changes": [
+            {
+                "note": "Round up when calculating remaining amounts in marketBuy functions",
+                "pr": 1162,
+                "networks": {
+                    "1": "0x5468a1dc173652ee28d249c271fa9933144746b1",
+                    "3": "0x2240dab907db71e64d3e0dba4800c83b5c502d4e",
+                    "42": "0x17992e4ffb22730138e4b62aaa6367fa9d3699a6"
+                }
+            }
+        ]
+    },
+    {
+        "name": "Forwarder",
+        "version": "1.0.0",
+        "changes": [
+            {
+                "note": "protocol v2 deploy",
+                "networks": {
+                    "1": "0x7afc2d5107af94c462a194d2c21b5bdd238709d6",
+                    "3": "0x3983e204b12b3c02fb0638caf2cd406a62e0ead3",
+                    "42": "0xd85e2fa7e7e252b27b01bf0d65c946959d2f45b8"
+                }
+            }
+        ]
+    }
+]
--- a/contracts/extensions/README.md
+++ b/contracts/extensions/README.md
@@ -0,0 +1,69 @@
+## Contract extensions
+
+Smart contracts that implement extensions for the 0x protocol.
+
+## Usage
+
+Contract extensions of the protocol can be found in the [contracts](./contracts) directory. This directory contains contracts that interact with the 2.0.0 contracts and will be used in production, such as the [Forwarder](https://github.com/0xProject/0x-protocol-specification/blob/master/v2/forwarder-specification.md) contract.
+
+## Bug bounty
+
+A bug bounty for the 2.0.0 contracts is ongoing! Instructions can be found [here](https://0xproject.com/wiki#Bug-Bounty).
+
+## Contributing
+
+We strongly recommend that the community help us make improvements and determine the future direction of the protocol. To report bugs within this package, please create an issue in this repository.
+
+For proposals regarding the 0x protocol's smart contract architecture, message format, or additional functionality, go to the [0x Improvement Proposals (ZEIPs)](https://github.com/0xProject/ZEIPs) repository and follow the contribution guidelines provided therein.
+
+Please read our [contribution guidelines](../../CONTRIBUTING.md) before getting started.
+
+### Install Dependencies
+
+If you don't have yarn workspaces enabled (Yarn < v1.0) - enable them:
+
+```bash
+yarn config set workspaces-experimental true
+```
+
+Then install dependencies
+
+```bash
+yarn install
+```
+
+### Build
+
+To build this package and all other monorepo packages that it depends on, run the following from the monorepo root directory:
+
+```bash
+PKG=@0x/contracts-extensions yarn build
+```
+
+Or continuously rebuild on change:
+
+```bash
+PKG=@0x/contracts-extensions yarn watch
+```
+
+### Clean
+
+```bash
+yarn clean
+```
+
+### Lint
+
+```bash
+yarn lint
+```
+
+### Run Tests
+
+```bash
+yarn test
+```
+
+#### Testing options
+
+Contracts testing options like coverage, profiling, revert traces or backing node choosing - are described [here](../TESTING.md).
--- a/contracts/extensions/compiler.json
+++ b/contracts/extensions/compiler.json
@@ -0,0 +1,22 @@
+{
+    "artifactsDir": "./generated-artifacts",
+    "contractsDir": "./contracts",
+    "compilerSettings": {
+        "optimizer": {
+            "enabled": true,
+            "runs": 1000000
+        },
+        "outputSelection": {
+            "*": {
+                "*": [
+                    "abi",
+                    "evm.bytecode.object",
+                    "evm.bytecode.sourceMap",
+                    "evm.deployedBytecode.object",
+                    "evm.deployedBytecode.sourceMap"
+                ]
+            }
+        }
+    },
+    "contracts": ["BalanceThresholdFilter", "DutchAuction", "Forwarder", "OrderMatcher", "OrderValidator"]
+}
--- a/contracts/extensions/contracts/BalanceThresholdFilter/BalanceThresholdFilter.sol
+++ b/contracts/extensions/contracts/BalanceThresholdFilter/BalanceThresholdFilter.sol
@@ -0,0 +1,45 @@
+/*
+
+  Copyright 2018 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity 0.4.24;
+
+import "@0x/contracts-interfaces/contracts/protocol/Exchange/IExchange.sol";
+import "./interfaces/IThresholdAsset.sol";
+import "./MixinBalanceThresholdFilterCore.sol";
+
+
+contract BalanceThresholdFilter is
+    MixinBalanceThresholdFilterCore
+{
+
+    /// @dev Constructs BalanceThresholdFilter.
+    /// @param exchange Address of 0x exchange.
+    /// @param thresholdAsset The asset that must be held by makers/takers.
+    /// @param balanceThreshold The minimum balance of `thresholdAsset` that must be held by makers/takers.
+    constructor(
+        address exchange,
+        address thresholdAsset,
+        uint256 balanceThreshold
+    )
+        public
+    {
+        EXCHANGE = IExchange(exchange);
+        THRESHOLD_ASSET = IThresholdAsset(thresholdAsset);
+        BALANCE_THRESHOLD = balanceThreshold;
+    }
+}
--- a/contracts/extensions/contracts/BalanceThresholdFilter/MixinBalanceThresholdFilterCore.sol
+++ b/contracts/extensions/contracts/BalanceThresholdFilter/MixinBalanceThresholdFilterCore.sol
@@ -0,0 +1,135 @@
+/*
+
+  Copyright 2018 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.4.24;
+
+import "@0x/contracts-libs/contracts/libs/LibExchangeSelectors.sol";
+import "@0x/contracts-libs/contracts/libs/LibOrder.sol";
+import "./mixins/MBalanceThresholdFilterCore.sol";
+import "./MixinExchangeCalldata.sol";
+
+
+contract MixinBalanceThresholdFilterCore is
+    MBalanceThresholdFilterCore,
+    MixinExchangeCalldata,
+    LibOrder,
+    LibExchangeSelectors
+{
+
+    /// @dev Executes an Exchange transaction iff the maker and taker meet 
+    ///      the hold at least `BALANCE_THRESHOLD` of the asset `THRESHOLD_ASSET` OR 
+    ///      the exchange function is a cancellation.
+    ///      Supported Exchange functions:
+    ///          batchFillOrders
+    ///          batchFillOrdersNoThrow
+    ///          batchFillOrKillOrders
+    ///          fillOrder
+    ///          fillOrderNoThrow
+    ///          fillOrKillOrder
+    ///          marketBuyOrders
+    ///          marketBuyOrdersNoThrow
+    ///          marketSellOrders
+    ///          marketSellOrdersNoThrow
+    ///          matchOrders
+    ///          cancelOrder
+    ///          batchCancelOrders
+    ///          cancelOrdersUpTo
+    ///     Trying to call any other exchange function will throw.
+    /// @param salt Arbitrary number to ensure uniqueness of transaction hash.
+    /// @param signerAddress Address of transaction signer.
+    /// @param signedExchangeTransaction AbiV2 encoded calldata.
+    /// @param signature Proof of signer transaction by signer.
+    function executeTransaction(
+        uint256 salt,
+        address signerAddress,
+        bytes signedExchangeTransaction,
+        bytes signature
+    ) 
+        external
+    {
+        // Get accounts whose balances must be validated
+        address[] memory addressesToValidate = getAddressesToValidate(signerAddress);
+
+        // Validate account balances
+        uint256 balanceThreshold = BALANCE_THRESHOLD;
+        IThresholdAsset thresholdAsset = THRESHOLD_ASSET;
+        for (uint256 i = 0; i < addressesToValidate.length; ++i) {
+            uint256 addressBalance = thresholdAsset.balanceOf(addressesToValidate[i]);
+            require(
+                addressBalance >= balanceThreshold,
+                "AT_LEAST_ONE_ADDRESS_DOES_NOT_MEET_BALANCE_THRESHOLD"
+            );
+        }
+        emit ValidatedAddresses(addressesToValidate);
+        
+        // All addresses are valid. Execute exchange function.
+        EXCHANGE.executeTransaction(
+            salt,
+            signerAddress,
+            signedExchangeTransaction,
+            signature
+        );
+    }
+
+    /// @dev Constructs an array of addresses to be validated.
+    ///      Addresses depend on which Exchange function is to be called
+    ///      (defined by `signedExchangeTransaction` above).
+    /// @param signerAddress Address of transaction signer.
+    /// @return addressesToValidate Array of addresses to validate.
+    function getAddressesToValidate(address signerAddress)
+        internal pure
+        returns (address[] memory addressesToValidate)
+    {
+        bytes4 exchangeFunctionSelector = bytes4(exchangeCalldataload(0));
+        // solhint-disable expression-indent
+        if (
+            exchangeFunctionSelector == BATCH_FILL_ORDERS_SELECTOR              ||
+            exchangeFunctionSelector == BATCH_FILL_ORDERS_NO_THROW_SELECTOR     ||
+            exchangeFunctionSelector == BATCH_FILL_OR_KILL_ORDERS_SELECTOR      ||
+            exchangeFunctionSelector == MARKET_BUY_ORDERS_SELECTOR              ||
+            exchangeFunctionSelector == MARKET_BUY_ORDERS_NO_THROW_SELECTOR     ||
+            exchangeFunctionSelector == MARKET_SELL_ORDERS_SELECTOR             ||
+            exchangeFunctionSelector == MARKET_SELL_ORDERS_NO_THROW_SELECTOR
+        ) {
+            addressesToValidate = loadMakerAddressesFromOrderArray(0);
+            addressesToValidate = addressesToValidate.append(signerAddress);
+        } else if (
+            exchangeFunctionSelector == FILL_ORDER_SELECTOR             ||
+            exchangeFunctionSelector == FILL_ORDER_NO_THROW_SELECTOR    ||
+            exchangeFunctionSelector == FILL_OR_KILL_ORDER_SELECTOR
+        ) {
+            address makerAddress = loadMakerAddressFromOrder(0);
+            addressesToValidate = addressesToValidate.append(makerAddress);
+            addressesToValidate = addressesToValidate.append(signerAddress);
+        } else if (exchangeFunctionSelector == MATCH_ORDERS_SELECTOR) {
+            address leftMakerAddress = loadMakerAddressFromOrder(0);
+            addressesToValidate = addressesToValidate.append(leftMakerAddress);
+            address rightMakerAddress = loadMakerAddressFromOrder(1);
+            addressesToValidate = addressesToValidate.append(rightMakerAddress);
+            addressesToValidate = addressesToValidate.append(signerAddress);
+        } else if (
+            exchangeFunctionSelector != CANCEL_ORDER_SELECTOR           &&
+            exchangeFunctionSelector != BATCH_CANCEL_ORDERS_SELECTOR    &&
+            exchangeFunctionSelector != CANCEL_ORDERS_UP_TO_SELECTOR
+        ) {
+            revert("INVALID_OR_BLOCKED_EXCHANGE_SELECTOR");
+        }
+        // solhint-enable expression-indent
+        return addressesToValidate;
+    }
+}
--- a/contracts/extensions/contracts/BalanceThresholdFilter/MixinExchangeCalldata.sol
+++ b/contracts/extensions/contracts/BalanceThresholdFilter/MixinExchangeCalldata.sol
@@ -0,0 +1,103 @@
+    
+    /*
+
+  Copyright 2018 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.4.24;
+
+import "./mixins/MExchangeCalldata.sol";
+import "@0x/contracts-libs/contracts/libs/LibAddressArray.sol";
+
+
+contract MixinExchangeCalldata is 
+    MExchangeCalldata
+{
+
+    using LibAddressArray for address[];
+
+    /// @dev Emulates the `calldataload` opcode on the embedded Exchange calldata,
+    ///      which is accessed through `signedExchangeTransaction`.
+    /// @param offset  Offset into the Exchange calldata.
+    /// @return value  Corresponding 32 byte value stored at `offset`.
+    function exchangeCalldataload(uint256 offset)
+        internal pure
+        returns (bytes32 value)
+    {
+        assembly {
+            // Pointer to exchange transaction
+            // 0x04 for calldata selector
+            // 0x40 to access `signedExchangeTransaction`, which is the third parameter
+            let exchangeTxPtr := calldataload(0x44)
+
+            // Offset into Exchange calldata
+            // We compute this by adding 0x24 to the `exchangeTxPtr` computed above.
+            // 0x04 for calldata selector
+            // 0x20 for length field of `signedExchangeTransaction`
+            let exchangeCalldataOffset := add(exchangeTxPtr, add(0x24, offset))
+            value := calldataload(exchangeCalldataOffset)
+        }
+        return value;
+    }
+
+    /// @dev Convenience function that skips the 4 byte selector when loading
+    ///      from the embedded Exchange calldata.
+    /// @param offset  Offset into the Exchange calldata (minus the 4 byte selector)
+    /// @return value  Corresponding 32 byte value stored at `offset` + 4.
+    function loadExchangeData(uint256 offset)
+        internal pure
+        returns (bytes32 value)
+    {
+        value = exchangeCalldataload(offset + 4);
+        return value;
+    }
+
+    /// @dev Extracts the maker address from an order stored in the Exchange calldata
+    ///      (which is embedded in `signedExchangeTransaction`).
+    /// @param orderParamIndex  Index of the order in the Exchange function's signature.
+    /// @return makerAddress The extracted maker address.
+    function loadMakerAddressFromOrder(uint256 orderParamIndex)
+        internal pure
+        returns (address makerAddress)
+    {
+        uint256 orderOffsetInBytes = orderParamIndex * 32;
+        uint256 orderPtr = uint256(loadExchangeData(orderOffsetInBytes));
+        makerAddress = address(loadExchangeData(orderPtr));
+        return makerAddress;
+    }
+
+    /// @dev Extracts the maker addresses from an array of orders stored in the Exchange calldata
+    ///      (which is embedded in `signedExchangeTransaction`).
+    /// @param orderArrayParamIndex  Index of the order array in the Exchange function's signature
+    /// @return makerAddresses The extracted maker addresses.
+    function loadMakerAddressesFromOrderArray(uint256 orderArrayParamIndex)
+        internal pure
+        returns (address[] makerAddresses)
+    {
+        uint256 orderArrayOffsetInBytes = orderArrayParamIndex * 32;
+        uint256 orderArrayPtr = uint256(loadExchangeData(orderArrayOffsetInBytes));
+        uint256 orderArrayLength = uint256(loadExchangeData(orderArrayPtr));
+        uint256 orderArrayLengthInBytes = orderArrayLength * 32;
+        uint256 orderArrayElementPtr = orderArrayPtr + 32;
+        uint256 orderArrayElementEndPtr = orderArrayElementPtr + orderArrayLengthInBytes;
+        for (uint orderPtrOffset = orderArrayElementPtr; orderPtrOffset < orderArrayElementEndPtr; orderPtrOffset += 32) {
+            uint256 orderPtr = uint256(loadExchangeData(orderPtrOffset));
+            address makerAddress = address(loadExchangeData(orderPtr + orderArrayElementPtr));
+            makerAddresses = makerAddresses.append(makerAddress);
+        }
+        return makerAddresses;
+    }
+}
--- a/contracts/extensions/contracts/BalanceThresholdFilter/interfaces/IBalanceThresholdFilterCore.sol
+++ b/contracts/extensions/contracts/BalanceThresholdFilter/interfaces/IBalanceThresholdFilterCore.sol
@@ -0,0 +1,55 @@
+
+/*
+
+  Copyright 2018 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.4.24;
+
+
+contract IBalanceThresholdFilterCore {
+    
+    /// @dev Executes an Exchange transaction iff the maker and taker meet 
+    ///      the hold at least `BALANCE_THRESHOLD` of the asset `THRESHOLD_ASSET` OR 
+    ///      the exchange function is a cancellation.
+    ///      Supported Exchange functions:
+    ///         - batchFillOrders
+    ///         - batchFillOrdersNoThrow
+    ///         - batchFillOrKillOrders
+    ///         - fillOrder
+    ///         - fillOrderNoThrow
+    ///         - fillOrKillOrder
+    ///         - marketBuyOrders
+    ///         - marketBuyOrdersNoThrow
+    ///         - marketSellOrders
+    ///         - marketSellOrdersNoThrow
+    ///         - matchOrders
+    ///         - cancelOrder
+    ///         - batchCancelOrders
+    ///         - cancelOrdersUpTo
+    ///     Trying to call any other exchange function will throw.
+    /// @param salt Arbitrary number to ensure uniqueness of transaction hash.
+    /// @param signerAddress Address of transaction signer.
+    /// @param signedExchangeTransaction AbiV2 encoded calldata.
+    /// @param signature Proof of signer transaction by signer.
+    function executeTransaction(
+        uint256 salt,
+        address signerAddress,
+        bytes signedExchangeTransaction,
+        bytes signature
+    ) 
+        external;
+}
--- a/contracts/extensions/contracts/BalanceThresholdFilter/interfaces/IThresholdAsset.sol
+++ b/contracts/extensions/contracts/BalanceThresholdFilter/interfaces/IThresholdAsset.sol
@@ -0,0 +1,31 @@
+/*
+
+  Copyright 2018 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.4.24;
+
+
+contract IThresholdAsset {
+
+    /// @param _owner The address from which the balance will be retrieved
+    /// @return Balance of owner
+    function balanceOf(address _owner)
+        external
+        view
+        returns (uint256);
+
+}
--- a/contracts/extensions/contracts/BalanceThresholdFilter/mixins/MBalanceThresholdFilterCore.sol
+++ b/contracts/extensions/contracts/BalanceThresholdFilter/mixins/MBalanceThresholdFilterCore.sol
@@ -0,0 +1,54 @@
+/*
+
+  Copyright 2018 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.4.24;
+
+import "@0x/contracts-interfaces/contracts/protocol/Exchange/IExchange.sol";
+import "../interfaces/IThresholdAsset.sol";
+import "../interfaces/IBalanceThresholdFilterCore.sol";
+
+
+contract MBalanceThresholdFilterCore is
+    IBalanceThresholdFilterCore
+{
+
+    // Points to 0x exchange contract
+    // solhint-disable var-name-mixedcase
+    IExchange internal EXCHANGE;
+
+    // The asset that must be held by makers/takers
+    IThresholdAsset internal THRESHOLD_ASSET;
+
+    // The minimum balance of `THRESHOLD_ASSET` that must be held by makers/takers
+    uint256 internal BALANCE_THRESHOLD;
+    // solhint-enable var-name-mixedcase
+
+    // Addresses that hold at least `BALANCE_THRESHOLD` of `THRESHOLD_ASSET`
+    event ValidatedAddresses (
+        address[] addresses
+    );
+
+    /// @dev Constructs an array of addresses to be validated.
+    ///      Addresses depend on which Exchange function is to be called
+    ///      (defined by `signedExchangeTransaction` above).
+    /// @param signerAddress Address of transaction signer.
+    /// @return addressesToValidate Array of addresses to validate.
+    function getAddressesToValidate(address signerAddress)
+        internal pure
+        returns (address[] memory addressesToValidate);
+}
--- a/contracts/extensions/contracts/BalanceThresholdFilter/mixins/MExchangeCalldata.sol
+++ b/contracts/extensions/contracts/BalanceThresholdFilter/mixins/MExchangeCalldata.sol
@@ -0,0 +1,56 @@
+    
+    /*
+
+  Copyright 2018 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.4.24;
+
+
+contract MExchangeCalldata {
+
+    /// @dev Emulates the `calldataload` opcode on the embedded Exchange calldata,
+    ///      which is accessed through `signedExchangeTransaction`.
+    /// @param offset  Offset into the Exchange calldata.
+    /// @return value  Corresponding 32 byte value stored at `offset`.
+    function exchangeCalldataload(uint256 offset)
+        internal pure
+        returns (bytes32 value);
+
+    /// @dev Convenience function that skips the 4 byte selector when loading
+    ///      from the embedded Exchange calldata.
+    /// @param offset  Offset into the Exchange calldata (minus the 4 byte selector)
+    /// @return value  Corresponding 32 byte value stored at `offset` + 4.
+    function loadExchangeData(uint256 offset)
+        internal pure
+        returns (bytes32 value);
+
+    /// @dev Extracts the maker address from an order stored in the Exchange calldata
+    ///      (which is embedded in `signedExchangeTransaction`).
+    /// @param orderParamIndex  Index of the order in the Exchange function's signature.
+    /// @return makerAddress The extracted maker address.
+    function loadMakerAddressFromOrder(uint256 orderParamIndex)
+        internal pure
+        returns (address makerAddress);
+
+    /// @dev Extracts the maker addresses from an array of orders stored in the Exchange calldata
+    ///      (which is embedded in `signedExchangeTransaction`).
+    /// @param orderArrayParamIndex  Index of the order array in the Exchange function's signature
+    /// @return makerAddresses The extracted maker addresses.
+    function loadMakerAddressesFromOrderArray(uint256 orderArrayParamIndex)
+        internal pure
+        returns (address[] makerAddresses);
+}
--- a/contracts/extensions/contracts/DutchAuction/DutchAuction.sol
+++ b/contracts/extensions/contracts/DutchAuction/DutchAuction.sol
@@ -0,0 +1,205 @@
+/*
+
+  Copyright 2018 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity 0.4.24;
+pragma experimental ABIEncoderV2;
+
+import "@0x/contracts-interfaces/contracts/protocol/Exchange/IExchange.sol";
+import "@0x/contracts-libs/contracts/libs/LibOrder.sol";
+import "@0x/contracts-tokens/contracts/tokens/ERC20Token/IERC20Token.sol";
+import "@0x/contracts-utils/contracts/utils/LibBytes/LibBytes.sol";
+import "@0x/contracts-utils/contracts/utils/SafeMath/SafeMath.sol";
+
+
+contract DutchAuction is
+    SafeMath
+{
+    using LibBytes for bytes;
+
+    // solhint-disable var-name-mixedcase
+    IExchange internal EXCHANGE;
+
+    struct AuctionDetails {
+        uint256 beginTimeSeconds;    // Auction begin unix timestamp: sellOrder.makerAssetData
+        uint256 endTimeSeconds;      // Auction end unix timestamp: sellOrder.expiryTimeSeconds
+        uint256 beginAmount;         // Auction begin amount: sellOrder.makerAssetData
+        uint256 endAmount;           // Auction end amount: sellOrder.takerAssetAmount
+        uint256 currentAmount;       // Calculated amount given block.timestamp
+        uint256 currentTimeSeconds;  // block.timestamp
+    }
+
+    constructor (address _exchange)
+        public
+    {
+        EXCHANGE = IExchange(_exchange);
+    }
+
+    /// @dev Matches the buy and sell orders at an amount given the following: the current block time, the auction
+    ///      start time and the auction begin amount. The sell order is a an order at the lowest amount
+    ///      at the end of the auction. Excess from the match is transferred to the seller.
+    ///      Over time the price moves from beginAmount to endAmount given the current block.timestamp.
+    ///      sellOrder.expiryTimeSeconds is the end time of the auction.
+    ///      sellOrder.takerAssetAmount is the end amount of the auction (lowest possible amount).
+    ///      sellOrder.makerAssetData is the ABI encoded Asset Proxy data with the following data appended
+    ///      buyOrder.makerAssetData is the buyers bid on the auction, must meet the amount for the current block timestamp
+    ///      (uint256 beginTimeSeconds, uint256 beginAmount).
+    ///      This function reverts in the following scenarios:
+    ///         * Auction has not started (auctionDetails.currentTimeSeconds < auctionDetails.beginTimeSeconds)
+    ///         * Auction has expired (auctionDetails.endTimeSeconds < auctionDetails.currentTimeSeconds)
+    ///         * Amount is invalid: Buy order amount is too low (buyOrder.makerAssetAmount < auctionDetails.currentAmount)
+    ///         * Amount is invalid: Invalid begin amount (auctionDetails.beginAmount > auctionDetails.endAmount)
+    ///         * Any failure in the 0x Match Orders
+    /// @param buyOrder The Buyer's order. This order is for the current expected price of the auction.
+    /// @param sellOrder The Seller's order. This order is for the lowest amount (at the end of the auction).
+    /// @param buySignature Proof that order was created by the buyer.
+    /// @param sellSignature Proof that order was created by the seller.
+    /// @return matchedFillResults amounts filled and fees paid by maker and taker of matched orders.
+    function matchOrders(
+        LibOrder.Order memory buyOrder,
+        LibOrder.Order memory sellOrder,
+        bytes memory buySignature,
+        bytes memory sellSignature
+    )
+        public
+        returns (LibFillResults.MatchedFillResults memory matchedFillResults)
+    {
+        AuctionDetails memory auctionDetails = getAuctionDetails(sellOrder);
+        // Ensure the auction has not yet started
+        require(
+            auctionDetails.currentTimeSeconds >= auctionDetails.beginTimeSeconds,
+            "AUCTION_NOT_STARTED"
+        );
+        // Ensure the auction has not expired. This will fail later in 0x but we can save gas by failing early
+        require(
+            sellOrder.expirationTimeSeconds > auctionDetails.currentTimeSeconds,
+            "AUCTION_EXPIRED"
+        );
+        // Validate the buyer amount is greater than the current auction amount
+        require(
+            buyOrder.makerAssetAmount >= auctionDetails.currentAmount,
+            "INVALID_AMOUNT"
+        );
+        // Match orders, maximally filling `buyOrder`
+        matchedFillResults = EXCHANGE.matchOrders(
+            buyOrder,
+            sellOrder,
+            buySignature,
+            sellSignature
+        );
+        // The difference in sellOrder.takerAssetAmount and current amount is given as spread to the matcher
+        // This may include additional spread from the buyOrder.makerAssetAmount and the currentAmount.
+        // e.g currentAmount is 30, sellOrder.takerAssetAmount is 10 and buyOrder.makerAssetamount is 40.
+        // 10 (40-30) is returned to the buyer, 20 (30-10) sent to the seller and 10 has previously
+        // been transferred to the seller during matchOrders
+        uint256 leftMakerAssetSpreadAmount = matchedFillResults.leftMakerAssetSpreadAmount;
+        if (leftMakerAssetSpreadAmount > 0) {
+            // ERC20 Asset data itself is encoded as follows:
+            //
+            // | Area     | Offset | Length  | Contents                            |
+            // |----------|--------|---------|-------------------------------------|
+            // | Header   | 0      | 4       | function selector                   |
+            // | Params   |        | 1 * 32  | function parameters:                |
+            // |          | 4      | 12      |   1. token address padding          |
+            // |          | 16     | 20      |   2. token address                  |
+            bytes memory assetData = sellOrder.takerAssetData;
+            address token = assetData.readAddress(16);
+            // Calculate the excess from the buy order. This can occur if the buyer sends in a higher
+            // amount than the calculated current amount
+            uint256 buyerExcessAmount = safeSub(buyOrder.makerAssetAmount, auctionDetails.currentAmount);
+            uint256 sellerExcessAmount = safeSub(leftMakerAssetSpreadAmount, buyerExcessAmount);
+            // Return the difference between auctionDetails.currentAmount and sellOrder.takerAssetAmount
+            // to the seller
+            if (sellerExcessAmount > 0) {
+                IERC20Token(token).transfer(sellOrder.makerAddress, sellerExcessAmount);
+            }
+            // Return the difference between buyOrder.makerAssetAmount and auctionDetails.currentAmount
+            // to the buyer
+            if (buyerExcessAmount > 0) {
+                IERC20Token(token).transfer(buyOrder.makerAddress, buyerExcessAmount);
+            }
+        }
+        return matchedFillResults;
+    }
+
+    /// @dev Calculates the Auction Details for the given order
+    /// @param order The sell order
+    /// @return AuctionDetails
+    function getAuctionDetails(
+        LibOrder.Order memory order
+    )
+        public
+        returns (AuctionDetails memory auctionDetails)
+    {
+        uint256 makerAssetDataLength = order.makerAssetData.length;
+        // It is unknown the encoded data of makerAssetData, we assume the last 64 bytes
+        // are the Auction Details encoding.
+        // Auction Details is encoded as follows:
+        //
+        // | Area     | Offset | Length  | Contents                            |
+        // |----------|--------|---------|-------------------------------------|
+        // | Params   |        | 2 * 32  | parameters:                         |
+        // |          | -64    | 32      |   1. auction begin unix timestamp   |
+        // |          | -32    | 32      |   2. auction begin begin amount     |
+        // ERC20 asset data length is 4+32, 64 for auction details results in min length 100
+        require(
+            makerAssetDataLength >= 100,
+            "INVALID_ASSET_DATA"
+        );
+        uint256 auctionBeginTimeSeconds = order.makerAssetData.readUint256(makerAssetDataLength - 64);
+        uint256 auctionBeginAmount = order.makerAssetData.readUint256(makerAssetDataLength - 32);
+        // Ensure the auction has a valid begin time
+        require(
+            order.expirationTimeSeconds > auctionBeginTimeSeconds,
+            "INVALID_BEGIN_TIME"
+        );
+        uint256 auctionDurationSeconds = order.expirationTimeSeconds-auctionBeginTimeSeconds;
+        // Ensure the auction goes from high to low
+        uint256 minAmount = order.takerAssetAmount;
+        require(
+            auctionBeginAmount > minAmount,
+            "INVALID_AMOUNT"
+        );
+        uint256 amountDelta = auctionBeginAmount-minAmount;
+        // solhint-disable-next-line not-rely-on-time
+        uint256 timestamp = block.timestamp;
+        auctionDetails.beginTimeSeconds = auctionBeginTimeSeconds;
+        auctionDetails.endTimeSeconds = order.expirationTimeSeconds;
+        auctionDetails.beginAmount = auctionBeginAmount;
+        auctionDetails.endAmount = minAmount;
+        auctionDetails.currentTimeSeconds = timestamp;
+
+        uint256 remainingDurationSeconds = order.expirationTimeSeconds-timestamp;
+        if (timestamp < auctionBeginTimeSeconds) {
+            // If the auction has not yet begun the current amount is the auctionBeginAmount
+            auctionDetails.currentAmount = auctionBeginAmount;
+        } else if (timestamp >= order.expirationTimeSeconds) {
+            // If the auction has ended the current amount is the minAmount.
+            // Auction end time is guaranteed by 0x Exchange due to the order expiration
+            auctionDetails.currentAmount = minAmount;
+        } else {
+            auctionDetails.currentAmount = safeAdd(
+                minAmount,
+                safeDiv(
+                    safeMul(remainingDurationSeconds, amountDelta),
+                    auctionDurationSeconds
+                )
+            );
+        }
+        return auctionDetails;
+    }
+}
--- a/packages/contracts/contracts/extensions/Forwarder/Forwarder.sol
+++ b/packages/contracts/contracts/extensions/Forwarder/Forwarder.sol
--- a/packages/contracts/contracts/extensions/Forwarder/MixinAssets.sol
+++ b/packages/contracts/contracts/extensions/Forwarder/MixinAssets.sol
@@ -16,12 +16,12 @@

 */

-pragma solidity 0.4.24;
+pragma solidity ^0.4.24;

-import "../../utils/LibBytes/LibBytes.sol";
-import "../../utils/Ownable/Ownable.sol";
-import "../../tokens/ERC20Token/IERC20Token.sol";
-import "../../tokens/ERC721Token/IERC721Token.sol";
+import "@0x/contracts-utils/contracts/utils/LibBytes/LibBytes.sol";
+import "@0x/contracts-utils/contracts/utils/Ownable/Ownable.sol";
+import "@0x/contracts-tokens/contracts/tokens/ERC20Token/IERC20Token.sol";
+import "@0x/contracts-tokens/contracts/tokens/ERC721Token/IERC721Token.sol";
 import "./libs/LibConstants.sol";
 import "./mixins/MAssets.sol";

--- a/packages/contracts/contracts/extensions/Forwarder/MixinExchangeWrapper.sol
+++ b/packages/contracts/contracts/extensions/Forwarder/MixinExchangeWrapper.sol
@@ -16,15 +16,15 @@

 */

-pragma solidity 0.4.24;
+pragma solidity ^0.4.24;
 pragma experimental ABIEncoderV2;

 import "./libs/LibConstants.sol";
 import "./mixins/MExchangeWrapper.sol";
-import "../../protocol/Exchange/libs/LibAbiEncoder.sol";
-import "../../protocol/Exchange/libs/LibOrder.sol";
-import "../../protocol/Exchange/libs/LibFillResults.sol";
-import "../../protocol/Exchange/libs/LibMath.sol";
+import "@0x/contracts-libs/contracts/libs/LibAbiEncoder.sol";
+import "@0x/contracts-libs/contracts/libs/LibOrder.sol";
+import "@0x/contracts-libs/contracts/libs/LibFillResults.sol";
+import "@0x/contracts-libs/contracts/libs/LibMath.sol";


 contract MixinExchangeWrapper is
--- a/packages/contracts/contracts/extensions/Forwarder/MixinForwarderCore.sol
+++ b/packages/contracts/contracts/extensions/Forwarder/MixinForwarderCore.sol
@@ -16,7 +16,7 @@

 */

-pragma solidity 0.4.24;
+pragma solidity ^0.4.24;
 pragma experimental ABIEncoderV2;

 import "./libs/LibConstants.sol";
@@ -24,10 +24,10 @@ import "./mixins/MWeth.sol";
 import "./mixins/MAssets.sol";
 import "./mixins/MExchangeWrapper.sol";
 import "./interfaces/IForwarderCore.sol";
-import "../../utils/LibBytes/LibBytes.sol";
-import "../../protocol/Exchange/libs/LibOrder.sol";
-import "../../protocol/Exchange/libs/LibFillResults.sol";
-import "../../protocol/Exchange/libs/LibMath.sol";
+import "@0x/contracts-utils/contracts/utils/LibBytes/LibBytes.sol";
+import "@0x/contracts-libs/contracts/libs/LibOrder.sol";
+import "@0x/contracts-libs/contracts/libs/LibFillResults.sol";
+import "@0x/contracts-libs/contracts/libs/LibMath.sol";


 contract MixinForwarderCore is
--- a/packages/contracts/contracts/extensions/Forwarder/MixinWeth.sol
+++ b/packages/contracts/contracts/extensions/Forwarder/MixinWeth.sol
@@ -16,9 +16,9 @@

 */

-pragma solidity 0.4.24;
+pragma solidity ^0.4.24;

-import "../../protocol/Exchange/libs/LibMath.sol";
+import "@0x/contracts-libs/contracts/libs/LibMath.sol";
 import "./libs/LibConstants.sol";
 import "./mixins/MWeth.sol";

--- a/packages/contracts/contracts/extensions/Forwarder/interfaces/IAssets.sol
+++ b/packages/contracts/contracts/extensions/Forwarder/interfaces/IAssets.sol
@@ -16,7 +16,7 @@

 */

-pragma solidity 0.4.24;
+pragma solidity ^0.4.24;


 contract IAssets {
--- a/packages/contracts/contracts/extensions/Forwarder/interfaces/IForwarder.sol
+++ b/packages/contracts/contracts/extensions/Forwarder/interfaces/IForwarder.sol
@@ -16,7 +16,7 @@

 */

-pragma solidity 0.4.24;
+pragma solidity ^0.4.24;
 pragma experimental ABIEncoderV2;

 import "./IForwarderCore.sol";
--- a/packages/contracts/contracts/extensions/Forwarder/interfaces/IForwarderCore.sol
+++ b/packages/contracts/contracts/extensions/Forwarder/interfaces/IForwarderCore.sol
@@ -16,11 +16,11 @@

 */

-pragma solidity 0.4.24;
+pragma solidity ^0.4.24;
 pragma experimental ABIEncoderV2;

-import "../../../protocol/Exchange/libs/LibOrder.sol";
-import "../../../protocol/Exchange/libs/LibFillResults.sol";
+import "@0x/contracts-libs/contracts/libs/LibOrder.sol";
+import "@0x/contracts-libs/contracts/libs/LibFillResults.sol";


 contract IForwarderCore {
--- a/packages/contracts/contracts/extensions/Forwarder/libs/LibConstants.sol
+++ b/packages/contracts/contracts/extensions/Forwarder/libs/LibConstants.sol
@@ -16,12 +16,12 @@

 */

-pragma solidity 0.4.24;
+pragma solidity ^0.4.24;

-import "../../../utils/LibBytes/LibBytes.sol";
-import "../../../protocol/Exchange/interfaces/IExchange.sol";
-import "../../../tokens/EtherToken/IEtherToken.sol";
-import "../../../tokens/ERC20Token/IERC20Token.sol";
+import "@0x/contracts-utils/contracts/utils/LibBytes/LibBytes.sol";
+import "@0x/contracts-interfaces/contracts/protocol/Exchange/IExchange.sol";
+import "@0x/contracts-tokens/contracts/tokens/EtherToken/IEtherToken.sol";
+import "@0x/contracts-tokens/contracts/tokens/ERC20Token/IERC20Token.sol";


 contract LibConstants {
--- a/packages/contracts/contracts/extensions/Forwarder/libs/LibForwarderErrors.sol
+++ b/packages/contracts/contracts/extensions/Forwarder/libs/LibForwarderErrors.sol
@@ -17,7 +17,7 @@
 */

 // solhint-disable
-pragma solidity 0.4.24;
+pragma solidity ^0.4.24;


 /// This contract is intended to serve as a reference, but is not actually used for efficiency reasons.
--- a/packages/contracts/contracts/extensions/Forwarder/mixins/MAssets.sol
+++ b/packages/contracts/contracts/extensions/Forwarder/mixins/MAssets.sol
@@ -16,7 +16,7 @@

 */

-pragma solidity 0.4.24;
+pragma solidity ^0.4.24;

 import "../interfaces/IAssets.sol";

--- a/packages/contracts/contracts/extensions/Forwarder/mixins/MExchangeWrapper.sol
+++ b/packages/contracts/contracts/extensions/Forwarder/mixins/MExchangeWrapper.sol
@@ -16,11 +16,11 @@

 */

-pragma solidity 0.4.24;
+pragma solidity ^0.4.24;
 pragma experimental ABIEncoderV2;

-import "../../../protocol/Exchange/libs/LibOrder.sol";
-import "../../../protocol/Exchange/libs/LibFillResults.sol";
+import "@0x/contracts-libs/contracts/libs/LibOrder.sol";
+import "@0x/contracts-libs/contracts/libs/LibFillResults.sol";


 contract MExchangeWrapper {
--- a/packages/contracts/contracts/extensions/Forwarder/mixins/MWeth.sol
+++ b/packages/contracts/contracts/extensions/Forwarder/mixins/MWeth.sol
@@ -16,7 +16,7 @@

 */

-pragma solidity 0.4.24;
+pragma solidity ^0.4.24;


 contract MWeth {
--- a/contracts/extensions/contracts/OrderMatcher/MixinAssets.sol
+++ b/contracts/extensions/contracts/OrderMatcher/MixinAssets.sol
@@ -0,0 +1,195 @@
+/*
+
+  Copyright 2018 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.4.24;
+
+import "@0x/contracts-utils/contracts/utils/LibBytes/LibBytes.sol";
+import "@0x/contracts-utils/contracts/utils/Ownable/Ownable.sol";
+import "@0x/contracts-tokens/contracts/tokens/ERC20Token/IERC20Token.sol";
+import "@0x/contracts-tokens/contracts/tokens/ERC721Token/IERC721Token.sol";
+import "./mixins/MAssets.sol";
+import "./libs/LibConstants.sol";
+
+
+contract MixinAssets is
+    MAssets,
+    Ownable,
+    LibConstants
+{
+    using LibBytes for bytes;
+
+    /// @dev Withdraws assets from this contract. The contract requires a ZRX balance in order to 
+    ///      function optimally, and this function allows the ZRX to be withdrawn by owner. It may also be
+    ///      used to withdraw assets that were accidentally sent to this contract.
+    /// @param assetData Byte array encoded for the respective asset proxy.
+    /// @param amount Amount of asset to withdraw.
+    function withdrawAsset(
+        bytes assetData,
+        uint256 amount
+    )
+        external
+        onlyOwner
+    {
+        transferAssetToSender(assetData, amount);
+    }
+
+    /// @dev Approves or disapproves an AssetProxy to spend asset.
+    /// @param assetData Byte array encoded for the respective asset proxy.
+    /// @param amount Amount of asset to approve for respective proxy.
+    function approveAssetProxy(
+        bytes assetData,
+        uint256 amount
+    )
+        external
+        onlyOwner
+    {
+        bytes4 proxyId = assetData.readBytes4(0);
+
+        if (proxyId == ERC20_DATA_ID) {
+            approveERC20Token(assetData, amount);
+        } else if (proxyId == ERC721_DATA_ID) {
+            approveERC721Token(assetData, amount);
+        } else {
+            revert("UNSUPPORTED_ASSET_PROXY");
+        }
+    }
+
+    /// @dev Transfers given amount of asset to sender.
+    /// @param assetData Byte array encoded for the respective asset proxy.
+    /// @param amount Amount of asset to transfer to sender.
+    function transferAssetToSender(
+        bytes memory assetData,
+        uint256 amount
+    )
+        internal
+    {
+        bytes4 proxyId = assetData.readBytes4(0);
+
+        if (proxyId == ERC20_DATA_ID) {
+            transferERC20Token(assetData, amount);
+        } else if (proxyId == ERC721_DATA_ID) {
+            transferERC721Token(assetData, amount);
+        } else {
+            revert("UNSUPPORTED_ASSET_PROXY");
+        }
+    }
+
+    /// @dev Decodes ERC20 assetData and transfers given amount to sender.
+    /// @param assetData Byte array encoded for the respective asset proxy.
+    /// @param amount Amount of asset to transfer to sender.
+    function transferERC20Token(
+        bytes memory assetData,
+        uint256 amount
+    )
+        internal
+    {
+        // 4 byte id + 12 0 bytes before ABI encoded token address.
+        address token = assetData.readAddress(16);
+
+        // Transfer tokens.
+        // We do a raw call so we can check the success separate
+        // from the return data.
+        bool success = token.call(abi.encodeWithSelector(
+            ERC20_TRANSFER_SELECTOR,
+            msg.sender,
+            amount
+        ));
+        require(
+            success,
+            "TRANSFER_FAILED"
+        );
+        
+        // Check return data.
+        // If there is no return data, we assume the token incorrectly
+        // does not return a bool. In this case we expect it to revert
+        // on failure, which was handled above.
+        // If the token does return data, we require that it is a single
+        // value that evaluates to true.
+        assembly {
+            if returndatasize {
+                success := 0
+                if eq(returndatasize, 32) {
+                    // First 64 bytes of memory are reserved scratch space
+                    returndatacopy(0, 0, 32)
+                    success := mload(0)
+                }
+            }
+        }
+        require(
+            success,
+            "TRANSFER_FAILED"
+        );
+    }
+
+    /// @dev Decodes ERC721 assetData and transfers given amount to sender.
+    /// @param assetData Byte array encoded for the respective asset proxy.
+    /// @param amount Amount of asset to transfer to sender.
+    function transferERC721Token(
+        bytes memory assetData,
+        uint256 amount
+    )
+        internal
+    {
+        require(
+            amount == 1,
+            "INVALID_AMOUNT"
+        );
+        // Decode asset data.
+        // 4 byte id + 12 0 bytes before ABI encoded token address.
+        address token = assetData.readAddress(16);
+        // 4 byte id + 32 byte ABI encoded token address before token id.
+        uint256 tokenId = assetData.readUint256(36);
+
+        // Perform transfer.
+        IERC721Token(token).transferFrom(
+            address(this),
+            msg.sender,
+            tokenId
+        );
+    }
+
+    /// @dev Sets approval for ERC20 AssetProxy.
+    /// @param assetData Byte array encoded for the respective asset proxy.
+    /// @param amount Amount of asset to approve for respective proxy.
+    function approveERC20Token(
+        bytes memory assetData,
+        uint256 amount
+    )
+        internal
+    {
+        address token = assetData.readAddress(16);
+        require(
+            IERC20Token(token).approve(ERC20_PROXY_ADDRESS, amount),
+            "APPROVAL_FAILED"
+        );
+    }
+
+    /// @dev Sets approval for ERC721 AssetProxy.
+    /// @param assetData Byte array encoded for the respective asset proxy.
+    /// @param amount Amount of asset to approve for respective proxy.
+    function approveERC721Token(
+        bytes memory assetData,
+        uint256 amount
+    )
+        internal
+    {
+        address token = assetData.readAddress(16);
+        bool approval = amount >= 1;
+        IERC721Token(token).setApprovalForAll(ERC721_PROXY_ADDRESS, approval);
+    }
+}
--- a/contracts/extensions/contracts/OrderMatcher/MixinMatchOrders.sol
+++ b/contracts/extensions/contracts/OrderMatcher/MixinMatchOrders.sol
@@ -0,0 +1,86 @@
+/*
+
+  Copyright 2018 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.4.24;
+pragma experimental ABIEncoderV2;
+
+import "./libs/LibConstants.sol";
+import "@0x/contracts-libs/contracts/libs/LibOrder.sol";
+import "@0x/contracts-libs/contracts/libs/LibFillResults.sol";
+import "@0x/contracts-utils/contracts/utils/Ownable/Ownable.sol";
+
+
+contract MixinMatchOrders is
+    Ownable,
+    LibConstants
+{
+    /// @dev Match two complementary orders that have a profitable spread.
+    ///      Each order is filled at their respective price point. However, the calculations are
+    ///      carried out as though the orders are both being filled at the right order's price point.
+    ///      The profit made by the left order is then used to fill the right order as much as possible.
+    ///      This results in a spread being taken in terms of both assets. The spread is held within this contract.
+    /// @param leftOrder First order to match.
+    /// @param rightOrder Second order to match.
+    /// @param leftSignature Proof that order was created by the left maker.
+    /// @param rightSignature Proof that order was created by the right maker.
+    function matchOrders(
+        LibOrder.Order memory leftOrder,
+        LibOrder.Order memory rightOrder,
+        bytes memory leftSignature,
+        bytes memory rightSignature
+    )
+        public
+        onlyOwner
+    {
+        // Match orders, maximally filling `leftOrder`
+        LibFillResults.MatchedFillResults memory matchedFillResults = EXCHANGE.matchOrders(
+            leftOrder,
+            rightOrder,
+            leftSignature,
+            rightSignature
+        );
+
+        uint256 leftMakerAssetSpreadAmount = matchedFillResults.leftMakerAssetSpreadAmount;
+        uint256 rightOrderTakerAssetAmount = rightOrder.takerAssetAmount;
+
+        // Do not attempt to call `fillOrder` if no spread was taken or `rightOrder` has been completely filled
+        if (leftMakerAssetSpreadAmount == 0 || matchedFillResults.right.takerAssetFilledAmount == rightOrderTakerAssetAmount) {
+            return;
+        }
+
+        // The `assetData` fields of the `rightOrder` could have been null for the `matchOrders` call. We reassign them before calling `fillOrder`.
+        rightOrder.makerAssetData = leftOrder.takerAssetData;
+        rightOrder.takerAssetData = leftOrder.makerAssetData;
+
+        // Query `rightOrder` info to check if it has been completely filled
+        // We need to make this check in case the `rightOrder` was partially filled before the `matchOrders` call
+        LibOrder.OrderInfo memory orderInfo = EXCHANGE.getOrderInfo(rightOrder);
+
+        // Do not attempt to call `fillOrder` if order has been completely filled
+        if (orderInfo.orderTakerAssetFilledAmount == rightOrderTakerAssetAmount) {
+            return;
+        }
+
+        // We do not need to pass in a signature since it was already validated in the `matchOrders` call
+        EXCHANGE.fillOrder(
+            rightOrder,
+            leftMakerAssetSpreadAmount,
+            ""
+        );
+    }
+}
--- a/contracts/extensions/contracts/OrderMatcher/OrderMatcher.sol
+++ b/contracts/extensions/contracts/OrderMatcher/OrderMatcher.sol
@@ -0,0 +1,38 @@
+/*
+
+  Copyright 2018 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity 0.4.24;
+pragma experimental ABIEncoderV2;
+
+import "@0x/contracts-utils/contracts/utils/Ownable/Ownable.sol";
+import "./libs/LibConstants.sol";
+import "./MixinMatchOrders.sol";
+import "./MixinAssets.sol";
+
+
+// solhint-disable no-empty-blocks
+contract OrderMatcher is
+    MixinMatchOrders,
+    MixinAssets
+{
+    constructor (address _exchange)
+        public
+        LibConstants(_exchange)
+        Ownable()
+    {}
+}
--- a/contracts/extensions/contracts/OrderMatcher/interfaces/IAssets.sol
+++ b/contracts/extensions/contracts/OrderMatcher/interfaces/IAssets.sol
@@ -0,0 +1,43 @@
+/*
+
+  Copyright 2018 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.4.24;
+
+
+contract IAssets {
+
+    /// @dev Withdraws assets from this contract. The contract requires a ZRX balance in order to 
+    ///      function optimally, and this function allows the ZRX to be withdrawn by owner. It may also be
+    ///      used to withdraw assets that were accidentally sent to this contract.
+    /// @param assetData Byte array encoded for the respective asset proxy.
+    /// @param amount Amount of asset to withdraw.
+    function withdrawAsset(
+        bytes assetData,
+        uint256 amount
+    )
+        external;
+
+    /// @dev Approves or disapproves an AssetProxy to spend asset.
+    /// @param assetData Byte array encoded for the respective asset proxy.
+    /// @param amount Amount of asset to approve for respective proxy.
+    function approveAssetProxy(
+        bytes assetData,
+        uint256 amount
+    )
+        external;
+}
--- a/contracts/extensions/contracts/OrderMatcher/interfaces/IMatchOrders.sol
+++ b/contracts/extensions/contracts/OrderMatcher/interfaces/IMatchOrders.sol
@@ -0,0 +1,43 @@
+/*
+
+  Copyright 2018 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.4.24;
+pragma experimental ABIEncoderV2;
+
+import "@0x/contracts-libs/contracts/libs/LibOrder.sol";
+
+
+contract IMatchOrders {
+
+    /// @dev Match two complementary orders that have a profitable spread.
+    ///      Each order is filled at their respective price point. However, the calculations are
+    ///      carried out as though the orders are both being filled at the right order's price point.
+    ///      The profit made by the left order is then used to fill the right order as much as possible.
+    ///      This results in a spread being taken in terms of both assets. The spread is held within this contract.
+    /// @param leftOrder First order to match.
+    /// @param rightOrder Second order to match.
+    /// @param leftSignature Proof that order was created by the left maker.
+    /// @param rightSignature Proof that order was created by the right maker.
+    function matchOrders(
+        LibOrder.Order memory leftOrder,
+        LibOrder.Order memory rightOrder,
+        bytes memory leftSignature,
+        bytes memory rightSignature
+    )
+        public;
+}
--- a/contracts/extensions/contracts/OrderMatcher/interfaces/IOrderMatcher.sol
+++ b/contracts/extensions/contracts/OrderMatcher/interfaces/IOrderMatcher.sol
@@ -0,0 +1,31 @@
+/*
+
+  Copyright 2018 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.4.24;
+
+import "@0x/contract-utils/contracts/utils/Ownable/IOwnable.sol";
+import "./IMatchOrders.sol";
+import "./IAssets.sol";
+
+
+// solhint-disable no-empty-blocks
+contract IOrderMatcher is
+    IOwnable,
+    IMatchOrders,
+    IAssets
+{}
--- a/contracts/extensions/contracts/OrderMatcher/libs/LibConstants.sol
+++ b/contracts/extensions/contracts/OrderMatcher/libs/LibConstants.sol
@@ -0,0 +1,56 @@
+/*
+
+  Copyright 2018 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.4.24;
+
+import "@0x/contracts-interfaces/contracts/protocol/Exchange/IExchange.sol";
+
+
+contract LibConstants {
+
+    // bytes4(keccak256("transfer(address,uint256)"))
+    bytes4 constant internal ERC20_TRANSFER_SELECTOR = 0xa9059cbb;
+    // bytes4(keccak256("ERC20Token(address)"))
+    bytes4 constant internal ERC20_DATA_ID = 0xf47261b0;
+    // bytes4(keccak256("ERC721Token(address,uint256)"))
+    bytes4 constant internal ERC721_DATA_ID = 0x02571792;
+ 
+     // solhint-disable var-name-mixedcase
+    IExchange internal EXCHANGE;
+    address internal ERC20_PROXY_ADDRESS;
+    address internal ERC721_PROXY_ADDRESS;
+    // solhint-enable var-name-mixedcase
+
+    constructor (address _exchange)
+        public
+    {
+        EXCHANGE = IExchange(_exchange);
+
+        ERC20_PROXY_ADDRESS = EXCHANGE.getAssetProxy(ERC20_DATA_ID);
+        require(
+            ERC20_PROXY_ADDRESS != address(0),
+            "UNREGISTERED_ASSET_PROXY"
+        );
+
+        ERC721_PROXY_ADDRESS = EXCHANGE.getAssetProxy(ERC721_DATA_ID);
+        require(
+            ERC721_PROXY_ADDRESS != address(0),
+            "UNREGISTERED_ASSET_PROXY"
+        );
+    }
+}
--- a/contracts/extensions/contracts/OrderMatcher/mixins/MAssets.sol
+++ b/contracts/extensions/contracts/OrderMatcher/mixins/MAssets.sol
@@ -0,0 +1,71 @@
+/*
+
+  Copyright 2018 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.4.24;
+
+import "../interfaces/IAssets.sol";
+
+
+contract MAssets is
+    IAssets
+{
+    /// @dev Transfers given amount of asset to sender.
+    /// @param assetData Byte array encoded for the respective asset proxy.
+    /// @param amount Amount of asset to transfer to sender.
+    function transferAssetToSender(
+        bytes memory assetData,
+        uint256 amount
+    )
+        internal;
+
+    /// @dev Decodes ERC20 assetData and transfers given amount to sender.
+    /// @param assetData Byte array encoded for the respective asset proxy.
+    /// @param amount Amount of asset to transfer to sender.
+    function transferERC20Token(
+        bytes memory assetData,
+        uint256 amount
+    )
+        internal;
+
+    /// @dev Decodes ERC721 assetData and transfers given amount to sender.
+    /// @param assetData Byte array encoded for the respective asset proxy.
+    /// @param amount Amount of asset to transfer to sender.
+    function transferERC721Token(
+        bytes memory assetData,
+        uint256 amount
+    )
+        internal;
+
+    /// @dev Sets approval for ERC20 AssetProxy.
+    /// @param assetData Byte array encoded for the respective asset proxy.
+    /// @param amount Amount of asset to approve for respective proxy.
+    function approveERC20Token(
+        bytes memory assetData,
+        uint256 amount
+    )
+        internal;
+
+    /// @dev Sets approval for ERC721 AssetProxy.
+    /// @param assetData Byte array encoded for the respective asset proxy.
+    /// @param amount Amount of asset to approve for respective proxy.
+    function approveERC721Token(
+        bytes memory assetData,
+        uint256 amount
+    )
+        internal;
+}
--- a/packages/contracts/contracts/extensions/OrderValidator/OrderValidator.sol
+++ b/packages/contracts/contracts/extensions/OrderValidator/OrderValidator.sol
@@ -19,11 +19,11 @@
 pragma solidity 0.4.24;
 pragma experimental ABIEncoderV2;

-import "../../protocol/Exchange/interfaces/IExchange.sol";
-import "../../protocol/Exchange/libs/LibOrder.sol";
-import "../../tokens/ERC20Token/IERC20Token.sol";
-import "../../tokens/ERC721Token/IERC721Token.sol";
-import "../../utils/LibBytes/LibBytes.sol";
+import "@0x/contracts-interfaces/contracts/protocol/Exchange/IExchange.sol";
+import "@0x/contracts-libs/contracts/libs/LibOrder.sol";
+import "@0x/contracts-tokens/contracts/tokens/ERC20Token/IERC20Token.sol";
+import "@0x/contracts-tokens/contracts/tokens/ERC721Token/IERC721Token.sol";
+import "@0x/contracts-utils/contracts/utils/LibBytes/LibBytes.sol";


 contract OrderValidator {
@@ -148,7 +148,7 @@ contract OrderValidator {
            balance = target == owner ? 1 : 0;

            // Check if ERC721Proxy is approved to spend tokenId
-            bool isApproved = IERC721Token(token).isApprovedForAll(target, assetProxy) || IERC721Token(token).getApproved(tokenId) == assetProxy;
+            bool isApproved = IERC721Token(token).isApprovedForAll(target, assetProxy);
            
            // Set alowance to 1 if ERC721Proxy is approved to spend tokenId
            allowance = isApproved ? 1 : 0;
--- a/contracts/extensions/package.json
+++ b/contracts/extensions/package.json
@@ -0,0 +1,94 @@
+{
+    "name": "@0x/contracts-extensions",
+    "version": "1.2.0",
+    "engines": {
+        "node": ">=6.12"
+    },
+    "description": "Smart contract extensions of 0x protocol",
+    "main": "lib/src/index.js",
+    "directories": {
+        "test": "test"
+    },
+    "scripts": {
+        "build": "yarn pre_build && tsc -b",
+        "build:ci": "yarn build",
+        "pre_build": "run-s compile generate_contract_wrappers",
+        "test": "yarn run_mocha",
+        "rebuild_and_test": "run-s build test",
+        "test:coverage": "SOLIDITY_COVERAGE=true run-s build run_mocha coverage:report:text coverage:report:lcov",
+        "test:profiler": "SOLIDITY_PROFILER=true run-s build run_mocha profiler:report:html",
+        "test:trace": "SOLIDITY_REVERT_TRACE=true run-s build run_mocha",
+        "run_mocha": "mocha --require source-map-support/register --require make-promises-safe 'lib/test/**/*.js' --timeout 100000 --bail --exit",
+        "compile": "sol-compiler",
+        "watch": "sol-compiler -w",
+        "clean": "shx rm -rf lib generated-artifacts generated-wrappers",
+        "generate_contract_wrappers": "abi-gen --abis  ${npm_package_config_abis} --template ../../node_modules/@0x/abi-gen-templates/contract.handlebars --partials '../../node_modules/@0x/abi-gen-templates/partials/**/*.handlebars' --output generated-wrappers --backend ethers",
+        "lint": "tslint --format stylish --project . --exclude ./generated-wrappers/**/* --exclude ./generated-artifacts/**/* --exclude **/lib/**/* && yarn lint-contracts",
+        "coverage:report:text": "istanbul report text",
+        "coverage:report:html": "istanbul report html && open coverage/index.html",
+        "profiler:report:html": "istanbul report html && open coverage/index.html",
+        "coverage:report:lcov": "istanbul report lcov",
+        "test:circleci": "yarn test",
+        "lint-contracts": "solhint -c ../.solhint.json contracts/**/**/**/**/*.sol"
+    },
+    "config": {
+        "abis": "generated-artifacts/@(BalanceThresholdFilter|DutchAuction|Forwarder|OrderMatcher|OrderValidator).json"
+    },
+    "repository": {
+        "type": "git",
+        "url": "https://github.com/0xProject/0x-monorepo.git"
+    },
+    "license": "Apache-2.0",
+    "bugs": {
+        "url": "https://github.com/0xProject/0x-monorepo/issues"
+    },
+    "homepage": "https://github.com/0xProject/0x-monorepo/contracts/extensions/README.md",
+    "devDependencies": {
+        "@0x/abi-gen": "^1.0.20",
+        "@0x/contract-wrappers": "^4.2.0",
+        "@0x/contracts-test-utils": "^1.0.3",
+        "@0x/dev-utils": "^1.0.22",
+        "@0x/sol-compiler": "^2.0.0",
+        "@0x/sol-cov": "^2.1.17",
+        "@0x/subproviders": "^2.1.9",
+        "@0x/tslint-config": "^2.0.0",
+        "@types/bn.js": "^4.11.0",
+        "@types/lodash": "4.14.104",
+        "@types/node": "*",
+        "@types/yargs": "^10.0.0",
+        "chai": "^4.0.1",
+        "chai-as-promised": "^7.1.0",
+        "chai-bignumber": "^2.0.1",
+        "dirty-chai": "^2.0.1",
+        "ethereumjs-abi": "0.6.5",
+        "make-promises-safe": "^1.1.0",
+        "mocha": "^4.1.0",
+        "npm-run-all": "^4.1.2",
+        "shx": "^0.2.2",
+        "solhint": "^1.4.1",
+        "tslint": "5.11.0",
+        "typescript": "3.0.1",
+        "yargs": "^10.0.3"
+    },
+    "dependencies": {
+        "@0x/base-contract": "^3.0.11",
+        "@0x/contracts-interfaces": "^1.0.3",
+        "@0x/contracts-libs": "^1.0.3",
+        "@0x/contracts-protocol": "^2.2.0",
+        "@0x/contracts-tokens": "^1.0.3",
+        "@0x/contracts-utils": "^1.0.3",
+        "@0x/order-utils": "^3.1.0",
+        "@0x/types": "^1.5.0",
+        "@0x/typescript-typings": "^3.0.6",
+        "@0x/utils": "^2.1.1",
+        "@0x/web3-wrapper": "^3.2.2",
+        "@types/js-combinatorics": "^0.5.29",
+        "bn.js": "^4.11.8",
+        "ethereum-types": "^1.1.4",
+        "ethereumjs-util": "^5.1.1",
+        "lodash": "^4.17.5"
+    },
+    "publishConfig": {
+        "access": "public"
+    }
+}
--- a/contracts/extensions/src/artifacts/index.ts
+++ b/contracts/extensions/src/artifacts/index.ts
@@ -0,0 +1,15 @@
+import { ContractArtifact } from 'ethereum-types';
+
+import * as BalanceThresholdFilter from '../../generated-artifacts/BalanceThresholdFilter.json';
+import * as DutchAuction from '../../generated-artifacts/DutchAuction.json';
+import * as Forwarder from '../../generated-artifacts/Forwarder.json';
+import * as OrderMatcher from '../../generated-artifacts/OrderMatcher.json';
+import * as OrderValidator from '../../generated-artifacts/OrderValidator.json';
+
+export const artifacts = {
+    BalanceThresholdFilter: BalanceThresholdFilter as ContractArtifact,
+    DutchAuction: DutchAuction as ContractArtifact,
+    Forwarder: Forwarder as ContractArtifact,
+    OrderMatcher: OrderMatcher as ContractArtifact,
+    OrderValidator: OrderValidator as ContractArtifact,
+};
--- a/contracts/extensions/src/index.ts
+++ b/contracts/extensions/src/index.ts
@@ -0,0 +1,2 @@
+export * from './artifacts';
+export * from './wrappers';
--- a/contracts/extensions/src/wrappers/index.ts
+++ b/contracts/extensions/src/wrappers/index.ts
@@ -0,0 +1,5 @@
+export * from '../../generated-wrappers/balance_threshold_filter';
+export * from '../../generated-wrappers/dutch_auction';
+export * from '../../generated-wrappers/forwarder';
+export * from '../../generated-wrappers/order_matcher';
+export * from '../../generated-wrappers/order_validator';
--- a/contracts/extensions/test/extensions/balance_threshold_filter.ts
+++ b/contracts/extensions/test/extensions/balance_threshold_filter.ts
--- a/contracts/extensions/test/extensions/dutch_auction.ts
+++ b/contracts/extensions/test/extensions/dutch_auction.ts
@@ -0,0 +1,378 @@
+import { DutchAuctionWrapper } from '@0x/contract-wrappers';
+import {
+    artifacts as protocolArtifacts,
+    ERC20Wrapper,
+    ERC721Wrapper,
+    ExchangeContract,
+    ExchangeWrapper,
+} from '@0x/contracts-protocol';
+import {
+    chaiSetup,
+    constants,
+    ContractName,
+    ERC20BalancesByOwner,
+    expectTransactionFailedAsync,
+    getLatestBlockTimestampAsync,
+    OrderFactory,
+    provider,
+    txDefaults,
+    web3Wrapper,
+} from '@0x/contracts-test-utils';
+import {
+    artifacts as tokensArtifacts,
+    DummyERC20TokenContract,
+    DummyERC721TokenContract,
+    WETH9Contract,
+} from '@0x/contracts-tokens';
+import { BlockchainLifecycle } from '@0x/dev-utils';
+import { assetDataUtils, generatePseudoRandomSalt } from '@0x/order-utils';
+import { RevertReason, SignedOrder } from '@0x/types';
+import { BigNumber } from '@0x/utils';
+import { Web3Wrapper } from '@0x/web3-wrapper';
+import * as chai from 'chai';
+import * as _ from 'lodash';
+
+import { DutchAuctionContract } from '../../generated-wrappers/dutch_auction';
+import { artifacts } from '../../src/artifacts';
+import { DutchAuctionTestWrapper } from '../utils/dutch_auction_test_wrapper';
+
+chaiSetup.configure();
+const expect = chai.expect;
+const blockchainLifecycle = new BlockchainLifecycle(web3Wrapper);
+const DECIMALS_DEFAULT = 18;
+
+describe(ContractName.DutchAuction, () => {
+    let makerAddress: string;
+    let owner: string;
+    let takerAddress: string;
+    let feeRecipientAddress: string;
+    let defaultMakerAssetAddress: string;
+
+    let zrxToken: DummyERC20TokenContract;
+    let erc20TokenA: DummyERC20TokenContract;
+    let erc721Token: DummyERC721TokenContract;
+    let dutchAuctionContract: DutchAuctionContract;
+    let wethContract: WETH9Contract;
+
+    let sellerOrderFactory: OrderFactory;
+    let buyerOrderFactory: OrderFactory;
+    let erc20Wrapper: ERC20Wrapper;
+    let erc20Balances: ERC20BalancesByOwner;
+    let currentBlockTimestamp: number;
+    let auctionBeginTimeSeconds: BigNumber;
+    let auctionEndTimeSeconds: BigNumber;
+    let auctionBeginAmount: BigNumber;
+    let auctionEndAmount: BigNumber;
+    let sellOrder: SignedOrder;
+    let buyOrder: SignedOrder;
+    let erc721MakerAssetIds: BigNumber[];
+    const tenMinutesInSeconds = 10 * 60;
+
+    let dutchAuctionTestWrapper: DutchAuctionTestWrapper;
+    let defaultERC20MakerAssetData: string;
+
+    before(async () => {
+        await blockchainLifecycle.startAsync();
+        const accounts = await web3Wrapper.getAvailableAddressesAsync();
+        const usedAddresses = ([owner, makerAddress, takerAddress, feeRecipientAddress] = accounts);
+
+        erc20Wrapper = new ERC20Wrapper(provider, usedAddresses, owner);
+
+        const numDummyErc20ToDeploy = 2;
+        [erc20TokenA, zrxToken] = await erc20Wrapper.deployDummyTokensAsync(
+            numDummyErc20ToDeploy,
+            constants.DUMMY_TOKEN_DECIMALS,
+        );
+        const erc20Proxy = await erc20Wrapper.deployProxyAsync();
+        await erc20Wrapper.setBalancesAndAllowancesAsync();
+
+        const erc721Wrapper = new ERC721Wrapper(provider, usedAddresses, owner);
+        [erc721Token] = await erc721Wrapper.deployDummyTokensAsync();
+        const erc721Proxy = await erc721Wrapper.deployProxyAsync();
+        await erc721Wrapper.setBalancesAndAllowancesAsync();
+        const erc721Balances = await erc721Wrapper.getBalancesAsync();
+        erc721MakerAssetIds = erc721Balances[makerAddress][erc721Token.address];
+
+        wethContract = await WETH9Contract.deployFrom0xArtifactAsync(tokensArtifacts.WETH9, provider, txDefaults);
+        erc20Wrapper.addDummyTokenContract(wethContract as any);
+
+        const zrxAssetData = assetDataUtils.encodeERC20AssetData(zrxToken.address);
+        const exchangeInstance = await ExchangeContract.deployFrom0xArtifactAsync(
+            protocolArtifacts.Exchange,
+            provider,
+            txDefaults,
+            zrxAssetData,
+        );
+        const exchangeWrapper = new ExchangeWrapper(exchangeInstance, provider);
+        await exchangeWrapper.registerAssetProxyAsync(erc20Proxy.address, owner);
+        await exchangeWrapper.registerAssetProxyAsync(erc721Proxy.address, owner);
+
+        await erc20Proxy.addAuthorizedAddress.sendTransactionAsync(exchangeInstance.address, {
+            from: owner,
+        });
+        await erc721Proxy.addAuthorizedAddress.sendTransactionAsync(exchangeInstance.address, {
+            from: owner,
+        });
+
+        const dutchAuctionInstance = await DutchAuctionContract.deployFrom0xArtifactAsync(
+            artifacts.DutchAuction,
+            provider,
+            txDefaults,
+            exchangeInstance.address,
+        );
+        dutchAuctionContract = new DutchAuctionContract(
+            dutchAuctionInstance.abi,
+            dutchAuctionInstance.address,
+            provider,
+        );
+        dutchAuctionTestWrapper = new DutchAuctionTestWrapper(dutchAuctionInstance, provider);
+
+        defaultMakerAssetAddress = erc20TokenA.address;
+        const defaultTakerAssetAddress = wethContract.address;
+
+        // Set up taker WETH balance and allowance
+        await web3Wrapper.awaitTransactionSuccessAsync(
+            await wethContract.deposit.sendTransactionAsync({
+                from: takerAddress,
+                value: Web3Wrapper.toBaseUnitAmount(new BigNumber(50), DECIMALS_DEFAULT),
+            }),
+        );
+        await web3Wrapper.awaitTransactionSuccessAsync(
+            await wethContract.approve.sendTransactionAsync(
+                erc20Proxy.address,
+                constants.UNLIMITED_ALLOWANCE_IN_BASE_UNITS,
+                { from: takerAddress },
+            ),
+        );
+        web3Wrapper.abiDecoder.addABI(exchangeInstance.abi);
+        web3Wrapper.abiDecoder.addABI(zrxToken.abi);
+        erc20Wrapper.addTokenOwnerAddress(dutchAuctionContract.address);
+
+        currentBlockTimestamp = await getLatestBlockTimestampAsync();
+        // Default auction begins 10 minutes ago
+        auctionBeginTimeSeconds = new BigNumber(currentBlockTimestamp).minus(tenMinutesInSeconds);
+        // Default auction ends 10 from now
+        auctionEndTimeSeconds = new BigNumber(currentBlockTimestamp).plus(tenMinutesInSeconds);
+        auctionBeginAmount = Web3Wrapper.toBaseUnitAmount(new BigNumber(10), DECIMALS_DEFAULT);
+        auctionEndAmount = Web3Wrapper.toBaseUnitAmount(new BigNumber(1), DECIMALS_DEFAULT);
+
+        // Default sell order and buy order are exact mirrors
+        const sellerDefaultOrderParams = {
+            salt: generatePseudoRandomSalt(),
+            exchangeAddress: exchangeInstance.address,
+            makerAddress,
+            feeRecipientAddress,
+            // taker address or sender address should be set to the ducth auction contract
+            takerAddress: dutchAuctionContract.address,
+            makerAssetData: DutchAuctionWrapper.encodeDutchAuctionAssetData(
+                assetDataUtils.encodeERC20AssetData(defaultMakerAssetAddress),
+                auctionBeginTimeSeconds,
+                auctionBeginAmount,
+            ),
+            takerAssetData: assetDataUtils.encodeERC20AssetData(defaultTakerAssetAddress),
+            makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(200), DECIMALS_DEFAULT),
+            takerAssetAmount: auctionEndAmount,
+            expirationTimeSeconds: auctionEndTimeSeconds,
+            makerFee: constants.ZERO_AMOUNT,
+            takerFee: constants.ZERO_AMOUNT,
+        };
+        // Default buy order is for the auction begin price
+        const buyerDefaultOrderParams = {
+            ...sellerDefaultOrderParams,
+            makerAddress: takerAddress,
+            makerAssetData: sellerDefaultOrderParams.takerAssetData,
+            takerAssetData: sellerDefaultOrderParams.makerAssetData,
+            makerAssetAmount: auctionBeginAmount,
+            takerAssetAmount: sellerDefaultOrderParams.makerAssetAmount,
+        };
+        const makerPrivateKey = constants.TESTRPC_PRIVATE_KEYS[accounts.indexOf(makerAddress)];
+        const takerPrivateKey = constants.TESTRPC_PRIVATE_KEYS[accounts.indexOf(takerAddress)];
+        sellerOrderFactory = new OrderFactory(makerPrivateKey, sellerDefaultOrderParams);
+        buyerOrderFactory = new OrderFactory(takerPrivateKey, buyerDefaultOrderParams);
+        defaultERC20MakerAssetData = assetDataUtils.encodeERC20AssetData(defaultMakerAssetAddress);
+    });
+    after(async () => {
+        await blockchainLifecycle.revertAsync();
+    });
+    beforeEach(async () => {
+        await blockchainLifecycle.startAsync();
+        erc20Balances = await erc20Wrapper.getBalancesAsync();
+        sellOrder = await sellerOrderFactory.newSignedOrderAsync();
+        buyOrder = await buyerOrderFactory.newSignedOrderAsync();
+    });
+    afterEach(async () => {
+        await blockchainLifecycle.revertAsync();
+    });
+    describe('matchOrders', () => {
+        it('should be worth the begin price at the begining of the auction', async () => {
+            auctionBeginTimeSeconds = new BigNumber(currentBlockTimestamp + 2);
+            const makerAssetData = DutchAuctionWrapper.encodeDutchAuctionAssetData(
+                defaultERC20MakerAssetData,
+                auctionBeginTimeSeconds,
+                auctionBeginAmount,
+            );
+            sellOrder = await sellerOrderFactory.newSignedOrderAsync({ makerAssetData });
+            const auctionDetails = await dutchAuctionTestWrapper.getAuctionDetailsAsync(sellOrder);
+            expect(auctionDetails.currentTimeSeconds).to.be.bignumber.lte(auctionBeginTimeSeconds);
+            expect(auctionDetails.currentAmount).to.be.bignumber.equal(auctionBeginAmount);
+            expect(auctionDetails.beginAmount).to.be.bignumber.equal(auctionBeginAmount);
+        });
+        it('should be be worth the end price at the end of the auction', async () => {
+            auctionBeginTimeSeconds = new BigNumber(currentBlockTimestamp - tenMinutesInSeconds * 2);
+            auctionEndTimeSeconds = new BigNumber(currentBlockTimestamp - tenMinutesInSeconds);
+            const makerAssetData = DutchAuctionWrapper.encodeDutchAuctionAssetData(
+                defaultERC20MakerAssetData,
+                auctionBeginTimeSeconds,
+                auctionBeginAmount,
+            );
+            sellOrder = await sellerOrderFactory.newSignedOrderAsync({
+                makerAssetData,
+                expirationTimeSeconds: auctionEndTimeSeconds,
+            });
+            const auctionDetails = await dutchAuctionTestWrapper.getAuctionDetailsAsync(sellOrder);
+            expect(auctionDetails.currentTimeSeconds).to.be.bignumber.gte(auctionEndTimeSeconds);
+            expect(auctionDetails.currentAmount).to.be.bignumber.equal(auctionEndAmount);
+            expect(auctionDetails.beginAmount).to.be.bignumber.equal(auctionBeginAmount);
+        });
+        it('should match orders at current amount and send excess to buyer', async () => {
+            const beforeAuctionDetails = await dutchAuctionTestWrapper.getAuctionDetailsAsync(sellOrder);
+            buyOrder = await buyerOrderFactory.newSignedOrderAsync({
+                makerAssetAmount: beforeAuctionDetails.currentAmount.times(2),
+            });
+            await dutchAuctionTestWrapper.matchOrdersAsync(buyOrder, sellOrder, takerAddress);
+            const afterAuctionDetails = await dutchAuctionTestWrapper.getAuctionDetailsAsync(sellOrder);
+            const newBalances = await erc20Wrapper.getBalancesAsync();
+            expect(newBalances[dutchAuctionContract.address][wethContract.address]).to.be.bignumber.equal(
+                constants.ZERO_AMOUNT,
+            );
+            // HACK gte used here due to a bug in ganache where the timestamp can change
+            // between multiple calls to the same block. Which can move the amount in our case
+            // ref: https://github.com/trufflesuite/ganache-core/issues/111
+            expect(newBalances[makerAddress][wethContract.address]).to.be.bignumber.gte(
+                erc20Balances[makerAddress][wethContract.address].plus(afterAuctionDetails.currentAmount),
+            );
+            expect(newBalances[takerAddress][wethContract.address]).to.be.bignumber.gte(
+                erc20Balances[takerAddress][wethContract.address].minus(beforeAuctionDetails.currentAmount),
+            );
+        });
+        it('maker fees on sellOrder are paid to the fee receipient', async () => {
+            sellOrder = await sellerOrderFactory.newSignedOrderAsync({
+                makerFee: new BigNumber(1),
+            });
+            await dutchAuctionTestWrapper.matchOrdersAsync(buyOrder, sellOrder, takerAddress);
+            const afterAuctionDetails = await dutchAuctionTestWrapper.getAuctionDetailsAsync(sellOrder);
+            const newBalances = await erc20Wrapper.getBalancesAsync();
+            expect(newBalances[makerAddress][wethContract.address]).to.be.bignumber.gte(
+                erc20Balances[makerAddress][wethContract.address].plus(afterAuctionDetails.currentAmount),
+            );
+            expect(newBalances[feeRecipientAddress][zrxToken.address]).to.be.bignumber.equal(
+                erc20Balances[feeRecipientAddress][zrxToken.address].plus(sellOrder.makerFee),
+            );
+        });
+        it('maker fees on buyOrder are paid to the fee receipient', async () => {
+            buyOrder = await buyerOrderFactory.newSignedOrderAsync({
+                makerFee: new BigNumber(1),
+            });
+            await dutchAuctionTestWrapper.matchOrdersAsync(buyOrder, sellOrder, takerAddress);
+            const newBalances = await erc20Wrapper.getBalancesAsync();
+            const afterAuctionDetails = await dutchAuctionTestWrapper.getAuctionDetailsAsync(sellOrder);
+            expect(newBalances[makerAddress][wethContract.address]).to.be.bignumber.gte(
+                erc20Balances[makerAddress][wethContract.address].plus(afterAuctionDetails.currentAmount),
+            );
+            expect(newBalances[feeRecipientAddress][zrxToken.address]).to.be.bignumber.equal(
+                erc20Balances[feeRecipientAddress][zrxToken.address].plus(buyOrder.makerFee),
+            );
+        });
+        it('should revert when auction expires', async () => {
+            auctionBeginTimeSeconds = new BigNumber(currentBlockTimestamp - tenMinutesInSeconds * 2);
+            auctionEndTimeSeconds = new BigNumber(currentBlockTimestamp - tenMinutesInSeconds);
+            const makerAssetData = DutchAuctionWrapper.encodeDutchAuctionAssetData(
+                defaultERC20MakerAssetData,
+                auctionBeginTimeSeconds,
+                auctionBeginAmount,
+            );
+            sellOrder = await sellerOrderFactory.newSignedOrderAsync({
+                expirationTimeSeconds: auctionEndTimeSeconds,
+                makerAssetData,
+            });
+            return expectTransactionFailedAsync(
+                dutchAuctionTestWrapper.matchOrdersAsync(buyOrder, sellOrder, takerAddress),
+                RevertReason.AuctionExpired,
+            );
+        });
+        it('cannot be filled for less than the current price', async () => {
+            buyOrder = await buyerOrderFactory.newSignedOrderAsync({
+                makerAssetAmount: sellOrder.takerAssetAmount,
+            });
+            return expectTransactionFailedAsync(
+                dutchAuctionTestWrapper.matchOrdersAsync(buyOrder, sellOrder, takerAddress),
+                RevertReason.AuctionInvalidAmount,
+            );
+        });
+        it('auction begin amount must be higher than final amount ', async () => {
+            sellOrder = await sellerOrderFactory.newSignedOrderAsync({
+                takerAssetAmount: auctionBeginAmount.plus(1),
+            });
+            return expectTransactionFailedAsync(
+                dutchAuctionTestWrapper.matchOrdersAsync(buyOrder, sellOrder, takerAddress),
+                RevertReason.AuctionInvalidAmount,
+            );
+        });
+        it('begin time is less than end time', async () => {
+            auctionBeginTimeSeconds = new BigNumber(auctionEndTimeSeconds).plus(tenMinutesInSeconds);
+            const makerAssetData = DutchAuctionWrapper.encodeDutchAuctionAssetData(
+                defaultERC20MakerAssetData,
+                auctionBeginTimeSeconds,
+                auctionBeginAmount,
+            );
+            sellOrder = await sellerOrderFactory.newSignedOrderAsync({
+                expirationTimeSeconds: auctionEndTimeSeconds,
+                makerAssetData,
+            });
+            return expectTransactionFailedAsync(
+                dutchAuctionTestWrapper.matchOrdersAsync(buyOrder, sellOrder, takerAddress),
+                RevertReason.AuctionInvalidBeginTime,
+            );
+        });
+        it('asset data contains auction parameters', async () => {
+            sellOrder = await sellerOrderFactory.newSignedOrderAsync({
+                makerAssetData: assetDataUtils.encodeERC20AssetData(defaultMakerAssetAddress),
+            });
+            return expectTransactionFailedAsync(
+                dutchAuctionTestWrapper.matchOrdersAsync(buyOrder, sellOrder, takerAddress),
+                RevertReason.InvalidAssetData,
+            );
+        });
+
+        describe('ERC721', () => {
+            it('should match orders when ERC721', async () => {
+                const makerAssetId = erc721MakerAssetIds[0];
+                const erc721MakerAssetData = assetDataUtils.encodeERC721AssetData(erc721Token.address, makerAssetId);
+                const makerAssetData = DutchAuctionWrapper.encodeDutchAuctionAssetData(
+                    erc721MakerAssetData,
+                    auctionBeginTimeSeconds,
+                    auctionBeginAmount,
+                );
+                sellOrder = await sellerOrderFactory.newSignedOrderAsync({
+                    makerAssetAmount: new BigNumber(1),
+                    makerAssetData,
+                });
+                buyOrder = await buyerOrderFactory.newSignedOrderAsync({
+                    takerAssetAmount: new BigNumber(1),
+                    takerAssetData: sellOrder.makerAssetData,
+                });
+                await dutchAuctionTestWrapper.matchOrdersAsync(buyOrder, sellOrder, takerAddress);
+                const afterAuctionDetails = await dutchAuctionTestWrapper.getAuctionDetailsAsync(sellOrder);
+                const newBalances = await erc20Wrapper.getBalancesAsync();
+                // HACK gte used here due to a bug in ganache where the timestamp can change
+                // between multiple calls to the same block. Which can move the amount in our case
+                // ref: https://github.com/trufflesuite/ganache-core/issues/111
+                expect(newBalances[makerAddress][wethContract.address]).to.be.bignumber.gte(
+                    erc20Balances[makerAddress][wethContract.address].plus(afterAuctionDetails.currentAmount),
+                );
+                const newOwner = await erc721Token.ownerOf.callAsync(makerAssetId);
+                expect(newOwner).to.be.bignumber.equal(takerAddress);
+            });
+        });
+    });
+});
--- a/contracts/extensions/test/extensions/forwarder.ts
+++ b/contracts/extensions/test/extensions/forwarder.ts
@@ -1,3 +1,29 @@
+import {
+    artifacts as protocolArtifacts,
+    ERC20Wrapper,
+    ERC721Wrapper,
+    ExchangeContract,
+    ExchangeWrapper,
+} from '@0x/contracts-protocol';
+import {
+    chaiSetup,
+    constants,
+    ContractName,
+    ERC20BalancesByOwner,
+    expectContractCreationFailedAsync,
+    expectTransactionFailedAsync,
+    OrderFactory,
+    provider,
+    sendTransactionResult,
+    txDefaults,
+    web3Wrapper,
+} from '@0x/contracts-test-utils';
+import {
+    artifacts as tokenArtifacts,
+    DummyERC20TokenContract,
+    DummyERC721TokenContract,
+    WETH9Contract,
+} from '@0x/contracts-tokens';
 import { BlockchainLifecycle } from '@0x/dev-utils';
 import { assetDataUtils } from '@0x/order-utils';
 import { RevertReason, SignedOrder } from '@0x/types';
@@ -6,26 +32,10 @@ import { Web3Wrapper } from '@0x/web3-wrapper';
 import * as chai from 'chai';
 import { TransactionReceiptWithDecodedLogs } from 'ethereum-types';

-import { DummyERC20TokenContract } from '../../generated-wrappers/dummy_erc20_token';
-import { DummyERC721TokenContract } from '../../generated-wrappers/dummy_erc721_token';
-import { ExchangeContract } from '../../generated-wrappers/exchange';
 import { ForwarderContract } from '../../generated-wrappers/forwarder';
-import { WETH9Contract } from '../../generated-wrappers/weth9';
 import { artifacts } from '../../src/artifacts';
-import {
-    expectContractCreationFailedAsync,
-    expectTransactionFailedAsync,
-    sendTransactionResult,
-} from '../utils/assertions';
-import { chaiSetup } from '../utils/chai_setup';
-import { constants } from '../utils/constants';
-import { ERC20Wrapper } from '../utils/erc20_wrapper';
-import { ERC721Wrapper } from '../utils/erc721_wrapper';
-import { ExchangeWrapper } from '../utils/exchange_wrapper';
+
 import { ForwarderWrapper } from '../utils/forwarder_wrapper';
-import { OrderFactory } from '../utils/order_factory';
-import { ContractName, ERC20BalancesByOwner } from '../utils/types';
-import { provider, txDefaults, web3Wrapper } from '../utils/web3_wrapper';

 chaiSetup.configure();
 const expect = chai.expect;
@@ -38,7 +48,6 @@ describe(ContractName.Forwarder, () => {
    let owner: string;
    let takerAddress: string;
    let feeRecipientAddress: string;
-    let otherAddress: string;
    let defaultMakerAssetAddress: string;
    let zrxAssetData: string;
    let wethAssetData: string;
@@ -68,7 +77,7 @@ describe(ContractName.Forwarder, () => {
    before(async () => {
        await blockchainLifecycle.startAsync();
        const accounts = await web3Wrapper.getAvailableAddressesAsync();
-        const usedAddresses = ([owner, makerAddress, takerAddress, feeRecipientAddress, otherAddress] = accounts);
+        const usedAddresses = ([owner, makerAddress, takerAddress, feeRecipientAddress] = accounts);

        const txHash = await web3Wrapper.sendTransactionAsync({ from: accounts[0], to: accounts[0], value: 0 });
        const transaction = await web3Wrapper.getTransactionByHashAsync(txHash);
@@ -91,14 +100,14 @@ describe(ContractName.Forwarder, () => {
        const erc721Balances = await erc721Wrapper.getBalancesAsync();
        erc721MakerAssetIds = erc721Balances[makerAddress][erc721Token.address];

-        wethContract = await WETH9Contract.deployFrom0xArtifactAsync(artifacts.WETH9, provider, txDefaults);
+        wethContract = await WETH9Contract.deployFrom0xArtifactAsync(tokenArtifacts.WETH9, provider, txDefaults);
        weth = new DummyERC20TokenContract(wethContract.abi, wethContract.address, provider);
        erc20Wrapper.addDummyTokenContract(weth);

        wethAssetData = assetDataUtils.encodeERC20AssetData(wethContract.address);
        zrxAssetData = assetDataUtils.encodeERC20AssetData(zrxToken.address);
        const exchangeInstance = await ExchangeContract.deployFrom0xArtifactAsync(
-            artifacts.Exchange,
+            protocolArtifacts.Exchange,
            provider,
            txDefaults,
            zrxAssetData,
@@ -169,7 +178,7 @@ describe(ContractName.Forwarder, () => {
    describe('constructor', () => {
        it('should revert if assetProxy is unregistered', async () => {
            const exchangeInstance = await ExchangeContract.deployFrom0xArtifactAsync(
-                artifacts.Exchange,
+                protocolArtifacts.Exchange,
                provider,
                txDefaults,
                zrxAssetData,
--- a/contracts/extensions/test/extensions/order_matcher.ts
+++ b/contracts/extensions/test/extensions/order_matcher.ts
@@ -0,0 +1,818 @@
+import {
+    artifacts as protocolArtifacts,
+    ERC20ProxyContract,
+    ERC20Wrapper,
+    ERC721ProxyContract,
+    ExchangeContract,
+    ExchangeFillEventArgs,
+    ExchangeWrapper,
+} from '@0x/contracts-protocol';
+import {
+    chaiSetup,
+    constants,
+    ERC20BalancesByOwner,
+    expectContractCreationFailedAsync,
+    expectTransactionFailedAsync,
+    LogDecoder,
+    OrderFactory,
+    provider,
+    sendTransactionResult,
+    txDefaults,
+    web3Wrapper,
+} from '@0x/contracts-test-utils';
+import { artifacts as tokenArtifacts, DummyERC20TokenContract, DummyERC721TokenContract } from '@0x/contracts-tokens';
+import { BlockchainLifecycle } from '@0x/dev-utils';
+import { assetDataUtils } from '@0x/order-utils';
+import { RevertReason } from '@0x/types';
+import { BigNumber } from '@0x/utils';
+import { Web3Wrapper } from '@0x/web3-wrapper';
+import * as chai from 'chai';
+import { LogWithDecodedArgs } from 'ethereum-types';
+import * as _ from 'lodash';
+
+import { OrderMatcherContract } from '../../generated-wrappers/order_matcher';
+import { artifacts } from '../../src/artifacts';
+
+const blockchainLifecycle = new BlockchainLifecycle(web3Wrapper);
+chaiSetup.configure();
+const expect = chai.expect;
+// tslint:disable:no-unnecessary-type-assertion
+describe('OrderMatcher', () => {
+    let makerAddressLeft: string;
+    let makerAddressRight: string;
+    let owner: string;
+    let takerAddress: string;
+    let feeRecipientAddressLeft: string;
+    let feeRecipientAddressRight: string;
+
+    let erc20TokenA: DummyERC20TokenContract;
+    let erc20TokenB: DummyERC20TokenContract;
+    let zrxToken: DummyERC20TokenContract;
+    let exchange: ExchangeContract;
+    let erc20Proxy: ERC20ProxyContract;
+    let erc721Proxy: ERC721ProxyContract;
+    let orderMatcher: OrderMatcherContract;
+
+    let erc20BalancesByOwner: ERC20BalancesByOwner;
+    let exchangeWrapper: ExchangeWrapper;
+    let erc20Wrapper: ERC20Wrapper;
+    let orderFactoryLeft: OrderFactory;
+    let orderFactoryRight: OrderFactory;
+
+    let leftMakerAssetData: string;
+    let leftTakerAssetData: string;
+    let defaultERC20MakerAssetAddress: string;
+    let defaultERC20TakerAssetAddress: string;
+
+    before(async () => {
+        await blockchainLifecycle.startAsync();
+    });
+    after(async () => {
+        await blockchainLifecycle.revertAsync();
+    });
+    before(async () => {
+        // Create accounts
+        const accounts = await web3Wrapper.getAvailableAddressesAsync();
+        // Hack(albrow): Both Prettier and TSLint insert a trailing comma below
+        // but that is invalid syntax as of TypeScript version >= 2.8. We don't
+        // have the right fine-grained configuration options in TSLint,
+        // Prettier, or TypeScript, to reconcile this, so we will just have to
+        // wait for them to sort it out. We disable TSLint and Prettier for
+        // this part of the code for now. This occurs several times in this
+        // file. See https://github.com/prettier/prettier/issues/4624.
+        // prettier-ignore
+        const usedAddresses = ([
+            owner,
+            makerAddressLeft,
+            makerAddressRight,
+            takerAddress,
+            feeRecipientAddressLeft,
+            // tslint:disable-next-line:trailing-comma
+            feeRecipientAddressRight
+        ] = _.slice(accounts, 0, 6));
+        // Create wrappers
+        erc20Wrapper = new ERC20Wrapper(provider, usedAddresses, owner);
+        // Deploy ERC20 token & ERC20 proxy
+        const numDummyErc20ToDeploy = 3;
+        [erc20TokenA, erc20TokenB, zrxToken] = await erc20Wrapper.deployDummyTokensAsync(
+            numDummyErc20ToDeploy,
+            constants.DUMMY_TOKEN_DECIMALS,
+        );
+        erc20Proxy = await erc20Wrapper.deployProxyAsync();
+        await erc20Wrapper.setBalancesAndAllowancesAsync();
+        // Deploy ERC721 proxy
+        erc721Proxy = await ERC721ProxyContract.deployFrom0xArtifactAsync(
+            protocolArtifacts.ERC721Proxy,
+            provider,
+            txDefaults,
+        );
+        // Depoy exchange
+        exchange = await ExchangeContract.deployFrom0xArtifactAsync(
+            protocolArtifacts.Exchange,
+            provider,
+            txDefaults,
+            assetDataUtils.encodeERC20AssetData(zrxToken.address),
+        );
+        exchangeWrapper = new ExchangeWrapper(exchange, provider);
+        await exchangeWrapper.registerAssetProxyAsync(erc20Proxy.address, owner);
+        await exchangeWrapper.registerAssetProxyAsync(erc721Proxy.address, owner);
+        // Authorize ERC20 trades by exchange
+        await web3Wrapper.awaitTransactionSuccessAsync(
+            await erc20Proxy.addAuthorizedAddress.sendTransactionAsync(exchange.address, {
+                from: owner,
+            }),
+            constants.AWAIT_TRANSACTION_MINED_MS,
+        );
+        // Deploy OrderMatcher
+        orderMatcher = await OrderMatcherContract.deployFrom0xArtifactAsync(
+            artifacts.OrderMatcher,
+            provider,
+            txDefaults,
+            exchange.address,
+        );
+        // Set default addresses
+        defaultERC20MakerAssetAddress = erc20TokenA.address;
+        defaultERC20TakerAssetAddress = erc20TokenB.address;
+        leftMakerAssetData = assetDataUtils.encodeERC20AssetData(defaultERC20MakerAssetAddress);
+        leftTakerAssetData = assetDataUtils.encodeERC20AssetData(defaultERC20TakerAssetAddress);
+        // Set OrderMatcher balances and allowances
+        await web3Wrapper.awaitTransactionSuccessAsync(
+            await erc20TokenA.setBalance.sendTransactionAsync(orderMatcher.address, constants.INITIAL_ERC20_BALANCE, {
+                from: owner,
+            }),
+            constants.AWAIT_TRANSACTION_MINED_MS,
+        );
+        await web3Wrapper.awaitTransactionSuccessAsync(
+            await erc20TokenB.setBalance.sendTransactionAsync(orderMatcher.address, constants.INITIAL_ERC20_BALANCE, {
+                from: owner,
+            }),
+            constants.AWAIT_TRANSACTION_MINED_MS,
+        );
+        await web3Wrapper.awaitTransactionSuccessAsync(
+            await orderMatcher.approveAssetProxy.sendTransactionAsync(
+                leftMakerAssetData,
+                constants.INITIAL_ERC20_ALLOWANCE,
+            ),
+            constants.AWAIT_TRANSACTION_MINED_MS,
+        );
+        await web3Wrapper.awaitTransactionSuccessAsync(
+            await orderMatcher.approveAssetProxy.sendTransactionAsync(
+                leftTakerAssetData,
+                constants.INITIAL_ERC20_ALLOWANCE,
+            ),
+            constants.AWAIT_TRANSACTION_MINED_MS,
+        );
+        // Create default order parameters
+        const defaultOrderParamsLeft = {
+            ...constants.STATIC_ORDER_PARAMS,
+            makerAddress: makerAddressLeft,
+            exchangeAddress: exchange.address,
+            makerAssetData: leftMakerAssetData,
+            takerAssetData: leftTakerAssetData,
+            feeRecipientAddress: feeRecipientAddressLeft,
+            makerFee: constants.ZERO_AMOUNT,
+            takerFee: constants.ZERO_AMOUNT,
+        };
+        const defaultOrderParamsRight = {
+            ...constants.STATIC_ORDER_PARAMS,
+            makerAddress: makerAddressRight,
+            exchangeAddress: exchange.address,
+            makerAssetData: leftTakerAssetData,
+            takerAssetData: leftMakerAssetData,
+            feeRecipientAddress: feeRecipientAddressRight,
+            makerFee: constants.ZERO_AMOUNT,
+            takerFee: constants.ZERO_AMOUNT,
+        };
+        const privateKeyLeft = constants.TESTRPC_PRIVATE_KEYS[accounts.indexOf(makerAddressLeft)];
+        orderFactoryLeft = new OrderFactory(privateKeyLeft, defaultOrderParamsLeft);
+        const privateKeyRight = constants.TESTRPC_PRIVATE_KEYS[accounts.indexOf(makerAddressRight)];
+        orderFactoryRight = new OrderFactory(privateKeyRight, defaultOrderParamsRight);
+    });
+    beforeEach(async () => {
+        await blockchainLifecycle.startAsync();
+    });
+    afterEach(async () => {
+        await blockchainLifecycle.revertAsync();
+    });
+    describe('constructor', () => {
+        it('should revert if assetProxy is unregistered', async () => {
+            const exchangeInstance = await ExchangeContract.deployFrom0xArtifactAsync(
+                protocolArtifacts.Exchange,
+                provider,
+                txDefaults,
+                constants.NULL_BYTES,
+            );
+            return expectContractCreationFailedAsync(
+                (OrderMatcherContract.deployFrom0xArtifactAsync(
+                    artifacts.OrderMatcher,
+                    provider,
+                    txDefaults,
+                    exchangeInstance.address,
+                ) as any) as sendTransactionResult,
+                RevertReason.UnregisteredAssetProxy,
+            );
+        });
+    });
+    describe('matchOrders', () => {
+        beforeEach(async () => {
+            erc20BalancesByOwner = await erc20Wrapper.getBalancesAsync();
+        });
+        it('should revert if not called by owner', async () => {
+            // Create orders to match
+            const signedOrderLeft = await orderFactoryLeft.newSignedOrderAsync({
+                makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(5), 18),
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(10), 18),
+            });
+            const signedOrderRight = await orderFactoryRight.newSignedOrderAsync({
+                makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(10), 18),
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(2), 18),
+            });
+            const data = exchange.matchOrders.getABIEncodedTransactionData(
+                signedOrderLeft,
+                signedOrderRight,
+                signedOrderLeft.signature,
+                signedOrderRight.signature,
+            );
+            await expectTransactionFailedAsync(
+                web3Wrapper.sendTransactionAsync({
+                    data,
+                    to: orderMatcher.address,
+                    from: takerAddress,
+                    gas: constants.MAX_MATCH_ORDERS_GAS,
+                }),
+                RevertReason.OnlyContractOwner,
+            );
+        });
+        it('should transfer the correct amounts when orders completely fill each other', async () => {
+            // Create orders to match
+            const signedOrderLeft = await orderFactoryLeft.newSignedOrderAsync({
+                makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(5), 18),
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(10), 18),
+            });
+            const signedOrderRight = await orderFactoryRight.newSignedOrderAsync({
+                makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(10), 18),
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(2), 18),
+            });
+            // Match signedOrderLeft with signedOrderRight
+            const expectedTransferAmounts = {
+                // Left Maker
+                amountSoldByLeftMaker: signedOrderLeft.makerAssetAmount,
+                amountBoughtByLeftMaker: signedOrderLeft.takerAssetAmount,
+                // Right Maker
+                amountSoldByRightMaker: signedOrderRight.makerAssetAmount,
+                amountBoughtByRightMaker: signedOrderRight.takerAssetAmount,
+                // Taker
+                leftMakerAssetSpreadAmount: signedOrderLeft.makerAssetAmount.minus(signedOrderRight.takerAssetAmount),
+            };
+            const initialLeftMakerAssetTakerBalance = await erc20TokenA.balanceOf.callAsync(orderMatcher.address);
+            const data = exchange.matchOrders.getABIEncodedTransactionData(
+                signedOrderLeft,
+                signedOrderRight,
+                signedOrderLeft.signature,
+                signedOrderRight.signature,
+            );
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await web3Wrapper.sendTransactionAsync({
+                    data,
+                    to: orderMatcher.address,
+                    from: owner,
+                    gas: constants.MAX_MATCH_ORDERS_GAS,
+                }),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            const newLeftMakerAssetTakerBalance = await erc20TokenA.balanceOf.callAsync(orderMatcher.address);
+            const newErc20Balances = await erc20Wrapper.getBalancesAsync();
+            expect(newErc20Balances[makerAddressLeft][defaultERC20MakerAssetAddress]).to.be.bignumber.equal(
+                erc20BalancesByOwner[makerAddressLeft][defaultERC20MakerAssetAddress].minus(
+                    expectedTransferAmounts.amountSoldByLeftMaker,
+                ),
+            );
+            expect(newErc20Balances[makerAddressRight][defaultERC20TakerAssetAddress]).to.be.bignumber.equal(
+                erc20BalancesByOwner[makerAddressRight][defaultERC20TakerAssetAddress].minus(
+                    expectedTransferAmounts.amountSoldByRightMaker,
+                ),
+            );
+            expect(newErc20Balances[makerAddressLeft][defaultERC20TakerAssetAddress]).to.be.bignumber.equal(
+                erc20BalancesByOwner[makerAddressLeft][defaultERC20TakerAssetAddress].plus(
+                    expectedTransferAmounts.amountBoughtByLeftMaker,
+                ),
+            );
+            expect(newErc20Balances[makerAddressRight][defaultERC20MakerAssetAddress]).to.be.bignumber.equal(
+                erc20BalancesByOwner[makerAddressRight][defaultERC20MakerAssetAddress].plus(
+                    expectedTransferAmounts.amountBoughtByRightMaker,
+                ),
+            );
+            expect(newLeftMakerAssetTakerBalance).to.be.bignumber.equal(
+                initialLeftMakerAssetTakerBalance.plus(expectedTransferAmounts.leftMakerAssetSpreadAmount),
+            );
+        });
+        it('should transfer the correct amounts when orders completely fill each other and taker doesnt take a profit', async () => {
+            // Create orders to match
+            const signedOrderLeft = await orderFactoryLeft.newSignedOrderAsync({
+                makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(5), 18),
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(10), 18),
+            });
+            const signedOrderRight = await orderFactoryRight.newSignedOrderAsync({
+                makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(10), 18),
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(5), 18),
+            });
+            // Match signedOrderLeft with signedOrderRight
+            const expectedTransferAmounts = {
+                // Left Maker
+                amountSoldByLeftMaker: signedOrderLeft.makerAssetAmount,
+                amountBoughtByLeftMaker: signedOrderLeft.takerAssetAmount,
+                // Right Maker
+                amountSoldByRightMaker: signedOrderRight.makerAssetAmount,
+                amountBoughtByRightMaker: signedOrderRight.takerAssetAmount,
+            };
+            const initialLeftMakerAssetTakerBalance = await erc20TokenA.balanceOf.callAsync(orderMatcher.address);
+            const data = exchange.matchOrders.getABIEncodedTransactionData(
+                signedOrderLeft,
+                signedOrderRight,
+                signedOrderLeft.signature,
+                signedOrderRight.signature,
+            );
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await web3Wrapper.sendTransactionAsync({
+                    data,
+                    to: orderMatcher.address,
+                    from: owner,
+                    gas: constants.MAX_MATCH_ORDERS_GAS,
+                }),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            const newLeftMakerAssetTakerBalance = await erc20TokenA.balanceOf.callAsync(orderMatcher.address);
+            const newErc20Balances = await erc20Wrapper.getBalancesAsync();
+            expect(newErc20Balances[makerAddressLeft][defaultERC20MakerAssetAddress]).to.be.bignumber.equal(
+                erc20BalancesByOwner[makerAddressLeft][defaultERC20MakerAssetAddress].minus(
+                    expectedTransferAmounts.amountSoldByLeftMaker,
+                ),
+            );
+            expect(newErc20Balances[makerAddressRight][defaultERC20TakerAssetAddress]).to.be.bignumber.equal(
+                erc20BalancesByOwner[makerAddressRight][defaultERC20TakerAssetAddress].minus(
+                    expectedTransferAmounts.amountSoldByRightMaker,
+                ),
+            );
+            expect(newErc20Balances[makerAddressLeft][defaultERC20TakerAssetAddress]).to.be.bignumber.equal(
+                erc20BalancesByOwner[makerAddressLeft][defaultERC20TakerAssetAddress].plus(
+                    expectedTransferAmounts.amountBoughtByLeftMaker,
+                ),
+            );
+            expect(newErc20Balances[makerAddressRight][defaultERC20MakerAssetAddress]).to.be.bignumber.equal(
+                erc20BalancesByOwner[makerAddressRight][defaultERC20MakerAssetAddress].plus(
+                    expectedTransferAmounts.amountBoughtByRightMaker,
+                ),
+            );
+            expect(newLeftMakerAssetTakerBalance).to.be.bignumber.equal(initialLeftMakerAssetTakerBalance);
+        });
+        it('should transfer the correct amounts when left order is completely filled and right order would be partially filled', async () => {
+            // Create orders to match
+            const signedOrderLeft = await orderFactoryLeft.newSignedOrderAsync({
+                makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(5), 18),
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(10), 18),
+            });
+            const signedOrderRight = await orderFactoryRight.newSignedOrderAsync({
+                makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(20), 18),
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(4), 18),
+            });
+            // Match signedOrderLeft with signedOrderRight
+            const expectedTransferAmounts = {
+                // Left Maker
+                amountSoldByLeftMaker: signedOrderLeft.makerAssetAmount,
+                amountBoughtByLeftMaker: signedOrderLeft.takerAssetAmount,
+                // Right Maker
+                amountSoldByRightMaker: signedOrderRight.makerAssetAmount,
+                amountBoughtByRightMaker: signedOrderRight.takerAssetAmount,
+                // Taker
+                leftMakerAssetSpreadAmount: signedOrderLeft.makerAssetAmount.minus(signedOrderRight.takerAssetAmount),
+                leftTakerAssetSpreadAmount: signedOrderRight.makerAssetAmount.minus(signedOrderLeft.takerAssetAmount),
+            };
+            const initialLeftMakerAssetTakerBalance = await erc20TokenA.balanceOf.callAsync(orderMatcher.address);
+            const initialLeftTakerAssetTakerBalance = await erc20TokenB.balanceOf.callAsync(orderMatcher.address);
+            // Match signedOrderLeft with signedOrderRight
+            const data = exchange.matchOrders.getABIEncodedTransactionData(
+                signedOrderLeft,
+                signedOrderRight,
+                signedOrderLeft.signature,
+                signedOrderRight.signature,
+            );
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await web3Wrapper.sendTransactionAsync({
+                    data,
+                    to: orderMatcher.address,
+                    from: owner,
+                    gas: constants.MAX_MATCH_ORDERS_GAS,
+                }),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            const newLeftMakerAssetTakerBalance = await erc20TokenA.balanceOf.callAsync(orderMatcher.address);
+            const newLeftTakerAssetTakerBalance = await erc20TokenB.balanceOf.callAsync(orderMatcher.address);
+            const newErc20Balances = await erc20Wrapper.getBalancesAsync();
+            expect(newErc20Balances[makerAddressLeft][defaultERC20MakerAssetAddress]).to.be.bignumber.equal(
+                erc20BalancesByOwner[makerAddressLeft][defaultERC20MakerAssetAddress].minus(
+                    expectedTransferAmounts.amountSoldByLeftMaker,
+                ),
+            );
+            expect(newErc20Balances[makerAddressRight][defaultERC20TakerAssetAddress]).to.be.bignumber.equal(
+                erc20BalancesByOwner[makerAddressRight][defaultERC20TakerAssetAddress].minus(
+                    expectedTransferAmounts.amountSoldByRightMaker,
+                ),
+            );
+            expect(newErc20Balances[makerAddressLeft][defaultERC20TakerAssetAddress]).to.be.bignumber.equal(
+                erc20BalancesByOwner[makerAddressLeft][defaultERC20TakerAssetAddress].plus(
+                    expectedTransferAmounts.amountBoughtByLeftMaker,
+                ),
+            );
+            expect(newErc20Balances[makerAddressRight][defaultERC20MakerAssetAddress]).to.be.bignumber.equal(
+                erc20BalancesByOwner[makerAddressRight][defaultERC20MakerAssetAddress].plus(
+                    expectedTransferAmounts.amountBoughtByRightMaker,
+                ),
+            );
+            expect(newLeftMakerAssetTakerBalance).to.be.bignumber.equal(
+                initialLeftMakerAssetTakerBalance.plus(expectedTransferAmounts.leftMakerAssetSpreadAmount),
+            );
+            expect(newLeftTakerAssetTakerBalance).to.be.bignumber.equal(
+                initialLeftTakerAssetTakerBalance.plus(expectedTransferAmounts.leftTakerAssetSpreadAmount),
+            );
+        });
+        it('should not call fillOrder when rightOrder is completely filled after matchOrders call and orders were never partially filled', async () => {
+            // Create orders to match
+            const signedOrderLeft = await orderFactoryLeft.newSignedOrderAsync({
+                makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(5), 18),
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(10), 18),
+            });
+            const signedOrderRight = await orderFactoryRight.newSignedOrderAsync({
+                makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(10), 18),
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(2), 18),
+            });
+            const data = exchange.matchOrders.getABIEncodedTransactionData(
+                signedOrderLeft,
+                signedOrderRight,
+                signedOrderLeft.signature,
+                signedOrderRight.signature,
+            );
+            const logDecoder = new LogDecoder(web3Wrapper, { ...artifacts, ...tokenArtifacts, ...protocolArtifacts });
+            const txReceipt = await logDecoder.getTxWithDecodedLogsAsync(
+                await web3Wrapper.sendTransactionAsync({
+                    data,
+                    to: orderMatcher.address,
+                    from: owner,
+                    gas: constants.MAX_MATCH_ORDERS_GAS,
+                }),
+            );
+            const fillLogs = _.filter(
+                txReceipt.logs,
+                log => (log as LogWithDecodedArgs<ExchangeFillEventArgs>).event === 'Fill',
+            );
+            // Only 2 Fill logs should exist for `matchOrders` call. `fillOrder` should not have been called and should not have emitted a Fill event.
+            expect(fillLogs.length).to.be.equal(2);
+        });
+        it('should not call fillOrder when rightOrder is completely filled after matchOrders call and orders were initially partially filled', async () => {
+            // Create orders to match
+            const signedOrderLeft = await orderFactoryLeft.newSignedOrderAsync({
+                makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(5), 18),
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(10), 18),
+            });
+            const signedOrderRight = await orderFactoryRight.newSignedOrderAsync({
+                makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(10), 18),
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(2), 18),
+            });
+            await exchangeWrapper.fillOrderAsync(signedOrderLeft, takerAddress, {
+                takerAssetFillAmount: signedOrderLeft.takerAssetAmount.dividedToIntegerBy(5),
+            });
+            await exchangeWrapper.fillOrderAsync(signedOrderRight, takerAddress, {
+                takerAssetFillAmount: signedOrderRight.takerAssetAmount.dividedToIntegerBy(5),
+            });
+            const data = exchange.matchOrders.getABIEncodedTransactionData(
+                signedOrderLeft,
+                signedOrderRight,
+                signedOrderLeft.signature,
+                signedOrderRight.signature,
+            );
+            const logDecoder = new LogDecoder(web3Wrapper, { ...artifacts, ...tokenArtifacts, ...protocolArtifacts });
+            const txReceipt = await logDecoder.getTxWithDecodedLogsAsync(
+                await web3Wrapper.sendTransactionAsync({
+                    data,
+                    to: orderMatcher.address,
+                    from: owner,
+                    gas: constants.MAX_MATCH_ORDERS_GAS,
+                }),
+            );
+            const fillLogs = _.filter(
+                txReceipt.logs,
+                log => (log as LogWithDecodedArgs<ExchangeFillEventArgs>).event === 'Fill',
+            );
+            // Only 2 Fill logs should exist for `matchOrders` call. `fillOrder` should not have been called and should not have emitted a Fill event.
+            expect(fillLogs.length).to.be.equal(2);
+        });
+        it('should only take a spread in rightMakerAsset if entire leftMakerAssetSpread amount can be used to fill rightOrder after matchOrders call', async () => {
+            // Create orders to match
+            const signedOrderLeft = await orderFactoryLeft.newSignedOrderAsync({
+                makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(10), 18),
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(0.9), 18),
+            });
+            const signedOrderRight = await orderFactoryRight.newSignedOrderAsync({
+                makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(100), 18),
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(990), 18),
+            });
+            const initialLeftMakerAssetSpreadAmount = Web3Wrapper.toBaseUnitAmount(new BigNumber(1.09), 18);
+            const leftTakerAssetSpreadAmount = initialLeftMakerAssetSpreadAmount
+                .times(signedOrderRight.makerAssetAmount)
+                .dividedToIntegerBy(signedOrderRight.takerAssetAmount);
+            // Match signedOrderLeft with signedOrderRight
+            const expectedTransferAmounts = {
+                // Left Maker
+                amountSoldByLeftMaker: signedOrderLeft.makerAssetAmount,
+                amountBoughtByLeftMaker: signedOrderLeft.takerAssetAmount,
+                // Right Maker
+                amountSoldByRightMaker: signedOrderLeft.takerAssetAmount.plus(leftTakerAssetSpreadAmount),
+                amountBoughtByRightMaker: signedOrderLeft.makerAssetAmount,
+                // Taker
+                leftMakerAssetSpreadAmount: constants.ZERO_AMOUNT,
+                leftTakerAssetSpreadAmount,
+            };
+            const initialLeftMakerAssetTakerBalance = await erc20TokenA.balanceOf.callAsync(orderMatcher.address);
+            const initialLeftTakerAssetTakerBalance = await erc20TokenB.balanceOf.callAsync(orderMatcher.address);
+            // Match signedOrderLeft with signedOrderRight
+            const data = exchange.matchOrders.getABIEncodedTransactionData(
+                signedOrderLeft,
+                signedOrderRight,
+                signedOrderLeft.signature,
+                signedOrderRight.signature,
+            );
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await web3Wrapper.sendTransactionAsync({
+                    data,
+                    to: orderMatcher.address,
+                    from: owner,
+                    gas: constants.MAX_MATCH_ORDERS_GAS,
+                }),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            const newLeftMakerAssetTakerBalance = await erc20TokenA.balanceOf.callAsync(orderMatcher.address);
+            const newLeftTakerAssetTakerBalance = await erc20TokenB.balanceOf.callAsync(orderMatcher.address);
+            const newErc20Balances = await erc20Wrapper.getBalancesAsync();
+            expect(newErc20Balances[makerAddressLeft][defaultERC20MakerAssetAddress]).to.be.bignumber.equal(
+                erc20BalancesByOwner[makerAddressLeft][defaultERC20MakerAssetAddress].minus(
+                    expectedTransferAmounts.amountSoldByLeftMaker,
+                ),
+            );
+            expect(newErc20Balances[makerAddressRight][defaultERC20TakerAssetAddress]).to.be.bignumber.equal(
+                erc20BalancesByOwner[makerAddressRight][defaultERC20TakerAssetAddress].minus(
+                    expectedTransferAmounts.amountSoldByRightMaker,
+                ),
+            );
+            expect(newErc20Balances[makerAddressLeft][defaultERC20TakerAssetAddress]).to.be.bignumber.equal(
+                erc20BalancesByOwner[makerAddressLeft][defaultERC20TakerAssetAddress].plus(
+                    expectedTransferAmounts.amountBoughtByLeftMaker,
+                ),
+            );
+            expect(newErc20Balances[makerAddressRight][defaultERC20MakerAssetAddress]).to.be.bignumber.equal(
+                erc20BalancesByOwner[makerAddressRight][defaultERC20MakerAssetAddress].plus(
+                    expectedTransferAmounts.amountBoughtByRightMaker,
+                ),
+            );
+            expect(newLeftMakerAssetTakerBalance).to.be.bignumber.equal(
+                initialLeftMakerAssetTakerBalance.plus(expectedTransferAmounts.leftMakerAssetSpreadAmount),
+            );
+            expect(newLeftTakerAssetTakerBalance).to.be.bignumber.equal(
+                initialLeftTakerAssetTakerBalance.plus(expectedTransferAmounts.leftTakerAssetSpreadAmount),
+            );
+        });
+        it("should succeed if rightOrder's makerAssetData and takerAssetData are not provided", async () => {
+            // Create orders to match
+            const signedOrderLeft = await orderFactoryLeft.newSignedOrderAsync({
+                makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(5), 18),
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(10), 18),
+            });
+            const signedOrderRight = await orderFactoryRight.newSignedOrderAsync({
+                makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(20), 18),
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(4), 18),
+            });
+            // Match signedOrderLeft with signedOrderRight
+            const expectedTransferAmounts = {
+                // Left Maker
+                amountSoldByLeftMaker: signedOrderLeft.makerAssetAmount,
+                amountBoughtByLeftMaker: signedOrderLeft.takerAssetAmount,
+                // Right Maker
+                amountSoldByRightMaker: signedOrderRight.makerAssetAmount,
+                amountBoughtByRightMaker: signedOrderRight.takerAssetAmount,
+                // Taker
+                leftMakerAssetSpreadAmount: signedOrderLeft.makerAssetAmount.minus(signedOrderRight.takerAssetAmount),
+                leftTakerAssetSpreadAmount: signedOrderRight.makerAssetAmount.minus(signedOrderLeft.takerAssetAmount),
+            };
+            const initialLeftMakerAssetTakerBalance = await erc20TokenA.balanceOf.callAsync(orderMatcher.address);
+            const initialLeftTakerAssetTakerBalance = await erc20TokenB.balanceOf.callAsync(orderMatcher.address);
+            // Match signedOrderLeft with signedOrderRight
+            signedOrderRight.makerAssetData = constants.NULL_BYTES;
+            signedOrderRight.takerAssetData = constants.NULL_BYTES;
+            const data = exchange.matchOrders.getABIEncodedTransactionData(
+                signedOrderLeft,
+                signedOrderRight,
+                signedOrderLeft.signature,
+                signedOrderRight.signature,
+            );
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await web3Wrapper.sendTransactionAsync({
+                    data,
+                    to: orderMatcher.address,
+                    from: owner,
+                    gas: constants.MAX_MATCH_ORDERS_GAS,
+                }),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            const newLeftMakerAssetTakerBalance = await erc20TokenA.balanceOf.callAsync(orderMatcher.address);
+            const newLeftTakerAssetTakerBalance = await erc20TokenB.balanceOf.callAsync(orderMatcher.address);
+            const newErc20Balances = await erc20Wrapper.getBalancesAsync();
+            expect(newErc20Balances[makerAddressLeft][defaultERC20MakerAssetAddress]).to.be.bignumber.equal(
+                erc20BalancesByOwner[makerAddressLeft][defaultERC20MakerAssetAddress].minus(
+                    expectedTransferAmounts.amountSoldByLeftMaker,
+                ),
+            );
+            expect(newErc20Balances[makerAddressRight][defaultERC20TakerAssetAddress]).to.be.bignumber.equal(
+                erc20BalancesByOwner[makerAddressRight][defaultERC20TakerAssetAddress].minus(
+                    expectedTransferAmounts.amountSoldByRightMaker,
+                ),
+            );
+            expect(newErc20Balances[makerAddressLeft][defaultERC20TakerAssetAddress]).to.be.bignumber.equal(
+                erc20BalancesByOwner[makerAddressLeft][defaultERC20TakerAssetAddress].plus(
+                    expectedTransferAmounts.amountBoughtByLeftMaker,
+                ),
+            );
+            expect(newErc20Balances[makerAddressRight][defaultERC20MakerAssetAddress]).to.be.bignumber.equal(
+                erc20BalancesByOwner[makerAddressRight][defaultERC20MakerAssetAddress].plus(
+                    expectedTransferAmounts.amountBoughtByRightMaker,
+                ),
+            );
+            expect(newLeftMakerAssetTakerBalance).to.be.bignumber.equal(
+                initialLeftMakerAssetTakerBalance.plus(expectedTransferAmounts.leftMakerAssetSpreadAmount),
+            );
+            expect(newLeftTakerAssetTakerBalance).to.be.bignumber.equal(
+                initialLeftTakerAssetTakerBalance.plus(expectedTransferAmounts.leftTakerAssetSpreadAmount),
+            );
+        });
+        it('should revert with the correct reason if matchOrders call reverts', async () => {
+            // Create orders to match
+            const signedOrderLeft = await orderFactoryLeft.newSignedOrderAsync({
+                makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(5), 18),
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(10), 18),
+            });
+            const signedOrderRight = await orderFactoryRight.newSignedOrderAsync({
+                makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(10), 18),
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(5), 18),
+            });
+            signedOrderRight.signature = `0xff${signedOrderRight.signature.slice(4)}`;
+            const data = exchange.matchOrders.getABIEncodedTransactionData(
+                signedOrderLeft,
+                signedOrderRight,
+                signedOrderLeft.signature,
+                signedOrderRight.signature,
+            );
+            await expectTransactionFailedAsync(
+                web3Wrapper.sendTransactionAsync({
+                    data,
+                    to: orderMatcher.address,
+                    from: owner,
+                    gas: constants.MAX_MATCH_ORDERS_GAS,
+                }),
+                RevertReason.InvalidOrderSignature,
+            );
+        });
+        it('should revert with the correct reason if fillOrder call reverts', async () => {
+            // Create orders to match
+            const signedOrderLeft = await orderFactoryLeft.newSignedOrderAsync({
+                makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(5), 18),
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(10), 18),
+            });
+            const signedOrderRight = await orderFactoryRight.newSignedOrderAsync({
+                makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(20), 18),
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(4), 18),
+            });
+            // Matcher will not have enough allowance to fill rightOrder
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await orderMatcher.approveAssetProxy.sendTransactionAsync(leftMakerAssetData, constants.ZERO_AMOUNT, {
+                    from: owner,
+                }),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            const data = exchange.matchOrders.getABIEncodedTransactionData(
+                signedOrderLeft,
+                signedOrderRight,
+                signedOrderLeft.signature,
+                signedOrderRight.signature,
+            );
+            await expectTransactionFailedAsync(
+                web3Wrapper.sendTransactionAsync({
+                    data,
+                    to: orderMatcher.address,
+                    from: owner,
+                    gas: constants.MAX_MATCH_ORDERS_GAS,
+                }),
+                RevertReason.TransferFailed,
+            );
+        });
+    });
+    describe('withdrawAsset', () => {
+        it('should allow owner to withdraw ERC20 tokens', async () => {
+            const erc20AWithdrawAmount = await erc20TokenA.balanceOf.callAsync(orderMatcher.address);
+            expect(erc20AWithdrawAmount).to.be.bignumber.gt(constants.ZERO_AMOUNT);
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await orderMatcher.withdrawAsset.sendTransactionAsync(leftMakerAssetData, erc20AWithdrawAmount, {
+                    from: owner,
+                }),
+            );
+            const newBalance = await erc20TokenA.balanceOf.callAsync(orderMatcher.address);
+            expect(newBalance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+        });
+        it('should allow owner to withdraw ERC721 tokens', async () => {
+            const erc721Token = await DummyERC721TokenContract.deployFrom0xArtifactAsync(
+                tokenArtifacts.DummyERC721Token,
+                provider,
+                txDefaults,
+                constants.DUMMY_TOKEN_NAME,
+                constants.DUMMY_TOKEN_SYMBOL,
+            );
+            const tokenId = new BigNumber(1);
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await erc721Token.mint.sendTransactionAsync(orderMatcher.address, tokenId, { from: owner }),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            const assetData = assetDataUtils.encodeERC721AssetData(erc721Token.address, tokenId);
+            const withdrawAmount = new BigNumber(1);
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await orderMatcher.withdrawAsset.sendTransactionAsync(assetData, withdrawAmount, { from: owner }),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            const erc721Owner = await erc721Token.ownerOf.callAsync(tokenId);
+            expect(erc721Owner).to.be.equal(owner);
+        });
+        it('should revert if not called by owner', async () => {
+            const erc20AWithdrawAmount = await erc20TokenA.balanceOf.callAsync(orderMatcher.address);
+            expect(erc20AWithdrawAmount).to.be.bignumber.gt(constants.ZERO_AMOUNT);
+            await expectTransactionFailedAsync(
+                orderMatcher.withdrawAsset.sendTransactionAsync(leftMakerAssetData, erc20AWithdrawAmount, {
+                    from: takerAddress,
+                }),
+                RevertReason.OnlyContractOwner,
+            );
+        });
+    });
+    describe('approveAssetProxy', () => {
+        it('should be able to set an allowance for ERC20 tokens', async () => {
+            const allowance = new BigNumber(55465465426546);
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await orderMatcher.approveAssetProxy.sendTransactionAsync(leftMakerAssetData, allowance, {
+                    from: owner,
+                }),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            const newAllowance = await erc20TokenA.allowance.callAsync(orderMatcher.address, erc20Proxy.address);
+            expect(newAllowance).to.be.bignumber.equal(allowance);
+        });
+        it('should be able to approve an ERC721 token by passing in allowance = 1', async () => {
+            const erc721Token = await DummyERC721TokenContract.deployFrom0xArtifactAsync(
+                tokenArtifacts.DummyERC721Token,
+                provider,
+                txDefaults,
+                constants.DUMMY_TOKEN_NAME,
+                constants.DUMMY_TOKEN_SYMBOL,
+            );
+            const assetData = assetDataUtils.encodeERC721AssetData(erc721Token.address, constants.ZERO_AMOUNT);
+            const allowance = new BigNumber(1);
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await orderMatcher.approveAssetProxy.sendTransactionAsync(assetData, allowance, { from: owner }),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            const isApproved = await erc721Token.isApprovedForAll.callAsync(orderMatcher.address, erc721Proxy.address);
+            expect(isApproved).to.be.equal(true);
+        });
+        it('should be able to approve an ERC721 token by passing in allowance > 1', async () => {
+            const erc721Token = await DummyERC721TokenContract.deployFrom0xArtifactAsync(
+                tokenArtifacts.DummyERC721Token,
+                provider,
+                txDefaults,
+                constants.DUMMY_TOKEN_NAME,
+                constants.DUMMY_TOKEN_SYMBOL,
+            );
+            const assetData = assetDataUtils.encodeERC721AssetData(erc721Token.address, constants.ZERO_AMOUNT);
+            const allowance = new BigNumber(2);
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await orderMatcher.approveAssetProxy.sendTransactionAsync(assetData, allowance, { from: owner }),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            const isApproved = await erc721Token.isApprovedForAll.callAsync(orderMatcher.address, erc721Proxy.address);
+            expect(isApproved).to.be.equal(true);
+        });
+        it('should revert if not called by owner', async () => {
+            const approval = new BigNumber(1);
+            await expectTransactionFailedAsync(
+                orderMatcher.approveAssetProxy.sendTransactionAsync(leftMakerAssetData, approval, {
+                    from: takerAddress,
+                }),
+                RevertReason.OnlyContractOwner,
+            );
+        });
+    });
+});
+// tslint:disable:max-file-line-count
+// tslint:enable:no-unnecessary-type-assertion
--- a/contracts/extensions/test/extensions/order_validator.ts
+++ b/contracts/extensions/test/extensions/order_validator.ts
@@ -1,3 +1,22 @@
+import {
+    artifacts as protocolArtifacts,
+    ERC20ProxyContract,
+    ERC20Wrapper,
+    ERC721ProxyContract,
+    ERC721Wrapper,
+    ExchangeContract,
+    ExchangeWrapper,
+} from '@0x/contracts-protocol';
+import {
+    chaiSetup,
+    constants,
+    OrderFactory,
+    OrderStatus,
+    provider,
+    txDefaults,
+    web3Wrapper,
+} from '@0x/contracts-test-utils';
+import { DummyERC20TokenContract, DummyERC721TokenContract } from '@0x/contracts-tokens';
 import { BlockchainLifecycle } from '@0x/dev-utils';
 import { assetDataUtils, orderHashUtils } from '@0x/order-utils';
 import { SignedOrder } from '@0x/types';
@@ -5,21 +24,8 @@ import { BigNumber } from '@0x/utils';
 import * as chai from 'chai';
 import * as _ from 'lodash';

-import { DummyERC20TokenContract } from '../../generated-wrappers/dummy_erc20_token';
-import { DummyERC721TokenContract } from '../../generated-wrappers/dummy_erc721_token';
-import { ERC20ProxyContract } from '../../generated-wrappers/erc20_proxy';
-import { ERC721ProxyContract } from '../../generated-wrappers/erc721_proxy';
-import { ExchangeContract } from '../../generated-wrappers/exchange';
 import { OrderValidatorContract } from '../../generated-wrappers/order_validator';
-import { artifacts } from '../../src/artifacts';
-import { chaiSetup } from '../utils/chai_setup';
-import { constants } from '../utils/constants';
-import { ERC20Wrapper } from '../utils/erc20_wrapper';
-import { ERC721Wrapper } from '../utils/erc721_wrapper';
-import { ExchangeWrapper } from '../utils/exchange_wrapper';
-import { OrderFactory } from '../utils/order_factory';
-import { OrderStatus } from '../utils/types';
-import { provider, txDefaults, web3Wrapper } from '../utils/web3_wrapper';
+import { artifacts } from '../../src/artifacts/index';

 chaiSetup.configure();
 const expect = chai.expect;
@@ -75,7 +81,7 @@ describe('OrderValidator', () => {

        const zrxAssetData = assetDataUtils.encodeERC20AssetData(zrxToken.address);
        exchange = await ExchangeContract.deployFrom0xArtifactAsync(
-            artifacts.Exchange,
+            protocolArtifacts.Exchange,
            provider,
            txDefaults,
            zrxAssetData,
@@ -198,7 +204,7 @@ describe('OrderValidator', () => {
                );
                expect(newAllowance).to.be.bignumber.equal(ERC721_ALLOWANCE);
            });
-            it('should return an allowance of 1 when ERC721Proxy is approved for specific tokenId', async () => {
+            it('should return an allowance of 0 when ERC721Proxy is approved for specific tokenId', async () => {
                await web3Wrapper.awaitTransactionSuccessAsync(
                    await erc721Token.mint.sendTransactionAsync(makerAddress, tokenId),
                    constants.AWAIT_TRANSACTION_MINED_MS,
@@ -213,7 +219,7 @@ describe('OrderValidator', () => {
                    makerAddress,
                    erc721AssetData,
                );
-                expect(newAllowance).to.be.bignumber.equal(ERC721_ALLOWANCE);
+                expect(newAllowance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
            });
        });
    });
@@ -248,8 +254,9 @@ describe('OrderValidator', () => {
                await erc721Token.mint.sendTransactionAsync(makerAddress, tokenId),
                constants.AWAIT_TRANSACTION_MINED_MS,
            );
+            const isApproved = true;
            await web3Wrapper.awaitTransactionSuccessAsync(
-                await erc721Token.approve.sendTransactionAsync(erc721Proxy.address, tokenId, {
+                await erc721Token.setApprovalForAll.sendTransactionAsync(erc721Proxy.address, isApproved, {
                    from: makerAddress,
                }),
                constants.AWAIT_TRANSACTION_MINED_MS,
@@ -311,8 +318,9 @@ describe('OrderValidator', () => {
                await erc721Token.mint.sendTransactionAsync(takerAddress, tokenId),
                constants.AWAIT_TRANSACTION_MINED_MS,
            );
+            const isApproved = true;
            await web3Wrapper.awaitTransactionSuccessAsync(
-                await erc721Token.approve.sendTransactionAsync(erc721Proxy.address, tokenId, {
+                await erc721Token.setApprovalForAll.sendTransactionAsync(erc721Proxy.address, isApproved, {
                    from: takerAddress,
                }),
                constants.AWAIT_TRANSACTION_MINED_MS,
@@ -465,8 +473,9 @@ describe('OrderValidator', () => {
                await erc721Token.mint.sendTransactionAsync(takerAddress, tokenId),
                constants.AWAIT_TRANSACTION_MINED_MS,
            );
+            const isApproved = true;
            await web3Wrapper.awaitTransactionSuccessAsync(
-                await erc721Token.approve.sendTransactionAsync(erc721Proxy.address, tokenId, {
+                await erc721Token.setApprovalForAll.sendTransactionAsync(erc721Proxy.address, isApproved, {
                    from: takerAddress,
                }),
                constants.AWAIT_TRANSACTION_MINED_MS,
--- a/contracts/extensions/test/global_hooks.ts
+++ b/contracts/extensions/test/global_hooks.ts
@@ -0,0 +1,17 @@
+import { env, EnvVars } from '@0x/dev-utils';
+
+import { coverage, profiler, provider } from '@0x/contracts-test-utils';
+before('start web3 provider', () => {
+    provider.start();
+});
+after('generate coverage report', async () => {
+    if (env.parseBoolean(EnvVars.SolidityCoverage)) {
+        const coverageSubprovider = coverage.getCoverageSubproviderSingleton();
+        await coverageSubprovider.writeCoverageAsync();
+    }
+    if (env.parseBoolean(EnvVars.SolidityProfiler)) {
+        const profilerSubprovider = profiler.getProfilerSubproviderSingleton();
+        await profilerSubprovider.writeProfilerOutputAsync();
+    }
+    provider.stop();
+});
--- a/contracts/extensions/test/utils/balance_threshold_wrapper.ts
+++ b/contracts/extensions/test/utils/balance_threshold_wrapper.ts
@@ -0,0 +1,283 @@
+import { artifacts as protocolArtifacts, ExchangeContract } from '@0x/contracts-protocol';
+import {
+    FillResults,
+    formatters,
+    LogDecoder,
+    OrderInfo,
+    orderUtils,
+    TransactionFactory,
+} from '@0x/contracts-test-utils';
+import { artifacts as tokensArtifacts } from '@0x/contracts-tokens';
+import { SignedOrder } from '@0x/types';
+import { BigNumber } from '@0x/utils';
+import { Web3Wrapper } from '@0x/web3-wrapper';
+import { Provider, TransactionReceiptWithDecodedLogs } from 'ethereum-types';
+import * as _ from 'lodash';
+
+import { BalanceThresholdFilterContract } from '../../generated-wrappers/balance_threshold_filter';
+import { artifacts } from '../../src/artifacts';
+
+export class BalanceThresholdWrapper {
+    private readonly _balanceThresholdFilter: BalanceThresholdFilterContract;
+    private readonly _signerTransactionFactory: TransactionFactory;
+    private readonly _exchange: ExchangeContract;
+    private readonly _web3Wrapper: Web3Wrapper;
+    private readonly _logDecoder: LogDecoder;
+    constructor(
+        balanceThresholdFilter: BalanceThresholdFilterContract,
+        exchangeContract: ExchangeContract,
+        signerTransactionFactory: TransactionFactory,
+        provider: Provider,
+    ) {
+        this._balanceThresholdFilter = balanceThresholdFilter;
+        this._exchange = exchangeContract;
+        this._signerTransactionFactory = signerTransactionFactory;
+        this._web3Wrapper = new Web3Wrapper(provider);
+        this._logDecoder = new LogDecoder(this._web3Wrapper, {
+            ...artifacts,
+            ...tokensArtifacts,
+            ...protocolArtifacts,
+        });
+    }
+    public async fillOrderAsync(
+        signedOrder: SignedOrder,
+        from: string,
+        opts: { takerAssetFillAmount?: BigNumber } = {},
+    ): Promise<TransactionReceiptWithDecodedLogs> {
+        const params = orderUtils.createFill(signedOrder, opts.takerAssetFillAmount);
+        const data = this._exchange.fillOrder.getABIEncodedTransactionData(
+            params.order,
+            params.takerAssetFillAmount,
+            params.signature,
+        );
+        const txReceipt = this._executeTransactionAsync(data, from);
+        return txReceipt;
+    }
+    public async fillOrKillOrderAsync(
+        signedOrder: SignedOrder,
+        from: string,
+        opts: { takerAssetFillAmount?: BigNumber } = {},
+    ): Promise<TransactionReceiptWithDecodedLogs> {
+        const params = orderUtils.createFill(signedOrder, opts.takerAssetFillAmount);
+        const data = this._exchange.fillOrKillOrder.getABIEncodedTransactionData(
+            params.order,
+            params.takerAssetFillAmount,
+            params.signature,
+        );
+        const txReceipt = this._executeTransactionAsync(data, from);
+        return txReceipt;
+    }
+    public async fillOrderNoThrowAsync(
+        signedOrder: SignedOrder,
+        from: string,
+        opts: { takerAssetFillAmount?: BigNumber; gas?: number } = {},
+    ): Promise<TransactionReceiptWithDecodedLogs> {
+        const params = orderUtils.createFill(signedOrder, opts.takerAssetFillAmount);
+        const data = this._exchange.fillOrderNoThrow.getABIEncodedTransactionData(
+            params.order,
+            params.takerAssetFillAmount,
+            params.signature,
+        );
+        const txReceipt = this._executeTransactionAsync(data, from, opts.gas);
+        return txReceipt;
+    }
+    public async batchFillOrdersAsync(
+        orders: SignedOrder[],
+        from: string,
+        opts: { takerAssetFillAmounts?: BigNumber[] } = {},
+    ): Promise<TransactionReceiptWithDecodedLogs> {
+        const params = formatters.createBatchFill(orders, opts.takerAssetFillAmounts);
+        const data = this._exchange.batchFillOrders.getABIEncodedTransactionData(
+            params.orders,
+            params.takerAssetFillAmounts,
+            params.signatures,
+        );
+        const txReceipt = this._executeTransactionAsync(data, from);
+        return txReceipt;
+    }
+    public async batchFillOrKillOrdersAsync(
+        orders: SignedOrder[],
+        from: string,
+        opts: { takerAssetFillAmounts?: BigNumber[] } = {},
+    ): Promise<TransactionReceiptWithDecodedLogs> {
+        const params = formatters.createBatchFill(orders, opts.takerAssetFillAmounts);
+        const data = this._exchange.batchFillOrKillOrders.getABIEncodedTransactionData(
+            params.orders,
+            params.takerAssetFillAmounts,
+            params.signatures,
+        );
+        const txReceipt = this._executeTransactionAsync(data, from);
+        return txReceipt;
+    }
+    public async batchFillOrdersNoThrowAsync(
+        orders: SignedOrder[],
+        from: string,
+        opts: { takerAssetFillAmounts?: BigNumber[]; gas?: number } = {},
+    ): Promise<TransactionReceiptWithDecodedLogs> {
+        const params = formatters.createBatchFill(orders, opts.takerAssetFillAmounts);
+        const data = this._exchange.batchFillOrKillOrders.getABIEncodedTransactionData(
+            params.orders,
+            params.takerAssetFillAmounts,
+            params.signatures,
+        );
+        const txReceipt = this._executeTransactionAsync(data, from, opts.gas);
+        return txReceipt;
+    }
+    public async marketSellOrdersAsync(
+        orders: SignedOrder[],
+        from: string,
+        opts: { takerAssetFillAmount: BigNumber },
+    ): Promise<TransactionReceiptWithDecodedLogs> {
+        const params = formatters.createMarketSellOrders(orders, opts.takerAssetFillAmount);
+        const data = this._exchange.marketSellOrders.getABIEncodedTransactionData(
+            params.orders,
+            params.takerAssetFillAmount,
+            params.signatures,
+        );
+        const txReceipt = this._executeTransactionAsync(data, from);
+        return txReceipt;
+    }
+    public async marketSellOrdersNoThrowAsync(
+        orders: SignedOrder[],
+        from: string,
+        opts: { takerAssetFillAmount: BigNumber; gas?: number },
+    ): Promise<TransactionReceiptWithDecodedLogs> {
+        const params = formatters.createMarketSellOrders(orders, opts.takerAssetFillAmount);
+        const data = this._exchange.marketSellOrdersNoThrow.getABIEncodedTransactionData(
+            params.orders,
+            params.takerAssetFillAmount,
+            params.signatures,
+        );
+        const txReceipt = this._executeTransactionAsync(data, from, opts.gas);
+        return txReceipt;
+    }
+    public async marketBuyOrdersAsync(
+        orders: SignedOrder[],
+        from: string,
+        opts: { makerAssetFillAmount: BigNumber },
+    ): Promise<TransactionReceiptWithDecodedLogs> {
+        const params = formatters.createMarketBuyOrders(orders, opts.makerAssetFillAmount);
+        const data = this._exchange.marketBuyOrders.getABIEncodedTransactionData(
+            params.orders,
+            params.makerAssetFillAmount,
+            params.signatures,
+        );
+        const txReceipt = this._executeTransactionAsync(data, from);
+        return txReceipt;
+    }
+    public async marketBuyOrdersNoThrowAsync(
+        orders: SignedOrder[],
+        from: string,
+        opts: { makerAssetFillAmount: BigNumber; gas?: number },
+    ): Promise<TransactionReceiptWithDecodedLogs> {
+        const params = formatters.createMarketBuyOrders(orders, opts.makerAssetFillAmount);
+        const data = this._exchange.marketBuyOrdersNoThrow.getABIEncodedTransactionData(
+            params.orders,
+            params.makerAssetFillAmount,
+            params.signatures,
+        );
+        const txReceipt = this._executeTransactionAsync(data, from, opts.gas);
+        return txReceipt;
+    }
+    public async cancelOrderAsync(signedOrder: SignedOrder, from: string): Promise<TransactionReceiptWithDecodedLogs> {
+        const params = orderUtils.createCancel(signedOrder);
+        const data = this._exchange.cancelOrder.getABIEncodedTransactionData(params.order);
+        const txReceipt = this._executeTransactionAsync(data, from);
+        return txReceipt;
+    }
+    public async batchCancelOrdersAsync(
+        orders: SignedOrder[],
+        from: string,
+    ): Promise<TransactionReceiptWithDecodedLogs> {
+        const params = formatters.createBatchCancel(orders);
+        const data = this._exchange.batchCancelOrders.getABIEncodedTransactionData(params.orders);
+        const txReceipt = this._executeTransactionAsync(data, from);
+        return txReceipt;
+    }
+    public async cancelOrdersUpToAsync(salt: BigNumber, from: string): Promise<TransactionReceiptWithDecodedLogs> {
+        const data = this._exchange.cancelOrdersUpTo.getABIEncodedTransactionData(salt);
+        const txReceipt = this._executeTransactionAsync(data, from);
+        return txReceipt;
+    }
+    public async getTakerAssetFilledAmountAsync(orderHashHex: string): Promise<BigNumber> {
+        const filledAmount = await this._exchange.filled.callAsync(orderHashHex);
+        return filledAmount;
+    }
+    public async isCancelledAsync(orderHashHex: string): Promise<boolean> {
+        const isCancelled = await this._exchange.cancelled.callAsync(orderHashHex);
+        return isCancelled;
+    }
+    public async getOrderEpochAsync(makerAddress: string, senderAddress: string): Promise<BigNumber> {
+        const orderEpoch = await this._exchange.orderEpoch.callAsync(makerAddress, senderAddress);
+        return orderEpoch;
+    }
+    public async getOrderInfoAsync(signedOrder: SignedOrder): Promise<OrderInfo> {
+        const orderInfo = await this._exchange.getOrderInfo.callAsync(signedOrder);
+        return orderInfo;
+    }
+    public async getOrdersInfoAsync(signedOrders: SignedOrder[]): Promise<OrderInfo[]> {
+        const ordersInfo = (await this._exchange.getOrdersInfo.callAsync(signedOrders)) as OrderInfo[];
+        return ordersInfo;
+    }
+    public async matchOrdersAsync(
+        signedOrderLeft: SignedOrder,
+        signedOrderRight: SignedOrder,
+        from: string,
+    ): Promise<TransactionReceiptWithDecodedLogs> {
+        const params = orderUtils.createMatchOrders(signedOrderLeft, signedOrderRight);
+        const data = await this._exchange.matchOrders.getABIEncodedTransactionData(
+            params.left,
+            params.right,
+            params.leftSignature,
+            params.rightSignature,
+        );
+        const txReceipt = this._executeTransactionAsync(data, from);
+        return txReceipt;
+    }
+    public async getFillOrderResultsAsync(
+        signedOrder: SignedOrder,
+        from: string,
+        opts: { takerAssetFillAmount?: BigNumber } = {},
+    ): Promise<FillResults> {
+        const params = orderUtils.createFill(signedOrder, opts.takerAssetFillAmount);
+        const fillResults = await this._exchange.fillOrder.callAsync(
+            params.order,
+            params.takerAssetFillAmount,
+            params.signature,
+            { from },
+        );
+        return fillResults;
+    }
+    public abiEncodeFillOrder(signedOrder: SignedOrder, opts: { takerAssetFillAmount?: BigNumber } = {}): string {
+        const params = orderUtils.createFill(signedOrder, opts.takerAssetFillAmount);
+        const data = this._exchange.fillOrder.getABIEncodedTransactionData(
+            params.order,
+            params.takerAssetFillAmount,
+            params.signature,
+        );
+        return data;
+    }
+    public getBalanceThresholdAddress(): string {
+        return this._balanceThresholdFilter.address;
+    }
+    public getExchangeAddress(): string {
+        return this._exchange.address;
+    }
+    private async _executeTransactionAsync(
+        abiEncodedExchangeTxData: string,
+        from: string,
+        gas?: number,
+    ): Promise<TransactionReceiptWithDecodedLogs> {
+        const signedExchangeTx = this._signerTransactionFactory.newSignedTransaction(abiEncodedExchangeTxData);
+        const txOpts = _.isUndefined(gas) ? { from } : { from, gas };
+        const txHash = await this._balanceThresholdFilter.executeTransaction.sendTransactionAsync(
+            signedExchangeTx.salt,
+            signedExchangeTx.signerAddress,
+            signedExchangeTx.data,
+            signedExchangeTx.signature,
+            txOpts,
+        );
+        const txReceipt = await this._logDecoder.getTxWithDecodedLogsAsync(txHash);
+        return txReceipt;
+    }
+}
--- a/contracts/extensions/test/utils/dutch_auction_test_wrapper.ts
+++ b/contracts/extensions/test/utils/dutch_auction_test_wrapper.ts
@@ -0,0 +1,62 @@
+import { artifacts as protocolArtifacts } from '@0x/contracts-protocol';
+import { LogDecoder } from '@0x/contracts-test-utils';
+import { artifacts as tokensArtifacts } from '@0x/contracts-tokens';
+import { DutchAuctionDetails, SignedOrder } from '@0x/types';
+import { Web3Wrapper } from '@0x/web3-wrapper';
+import { Provider, TransactionReceiptWithDecodedLogs } from 'ethereum-types';
+import * as _ from 'lodash';
+
+import { DutchAuctionContract } from '../../generated-wrappers/dutch_auction';
+import { artifacts } from '../../src/artifacts';
+
+export class DutchAuctionTestWrapper {
+    private readonly _dutchAuctionContract: DutchAuctionContract;
+    private readonly _web3Wrapper: Web3Wrapper;
+    private readonly _logDecoder: LogDecoder;
+
+    constructor(contractInstance: DutchAuctionContract, provider: Provider) {
+        this._dutchAuctionContract = contractInstance;
+        this._web3Wrapper = new Web3Wrapper(provider);
+        this._logDecoder = new LogDecoder(this._web3Wrapper, {
+            ...artifacts,
+            ...tokensArtifacts,
+            ...protocolArtifacts,
+        });
+    }
+    /**
+     * Matches the buy and sell orders at an amount given the following: the current block time, the auction
+     * start time and the auction begin amount. The sell order is a an order at the lowest amount
+     * at the end of the auction. Excess from the match is transferred to the seller.
+     * Over time the price moves from beginAmount to endAmount given the current block.timestamp.
+     * @param buyOrder The Buyer's order. This order is for the current expected price of the auction.
+     * @param sellOrder The Seller's order. This order is for the lowest amount (at the end of the auction).
+     * @param from Address the transaction is being sent from.
+     * @return Transaction receipt with decoded logs.
+     */
+    public async matchOrdersAsync(
+        buyOrder: SignedOrder,
+        sellOrder: SignedOrder,
+        from: string,
+    ): Promise<TransactionReceiptWithDecodedLogs> {
+        const txHash = await this._dutchAuctionContract.matchOrders.sendTransactionAsync(
+            buyOrder,
+            sellOrder,
+            buyOrder.signature,
+            sellOrder.signature,
+            {
+                from,
+            },
+        );
+        const tx = await this._logDecoder.getTxWithDecodedLogsAsync(txHash);
+        return tx;
+    }
+    /**
+     * Calculates the Auction Details for the given order
+     * @param sellOrder The Seller's order. This order is for the lowest amount (at the end of the auction).
+     * @return The dutch auction details.
+     */
+    public async getAuctionDetailsAsync(sellOrder: SignedOrder): Promise<DutchAuctionDetails> {
+        const auctionDetails = await this._dutchAuctionContract.getAuctionDetails.callAsync(sellOrder);
+        return auctionDetails;
+    }
+}
--- a/contracts/extensions/test/utils/forwarder_wrapper.ts
+++ b/contracts/extensions/test/utils/forwarder_wrapper.ts
@@ -1,3 +1,6 @@
+import { artifacts as protocolArtifacts } from '@0x/contracts-protocol';
+import { constants, formatters, LogDecoder, MarketSellOrders } from '@0x/contracts-test-utils';
+import { artifacts as tokensArtifacts } from '@0x/contracts-tokens';
 import { SignedOrder } from '@0x/types';
 import { BigNumber } from '@0x/utils';
 import { Web3Wrapper } from '@0x/web3-wrapper';
@@ -5,11 +8,7 @@ import { Provider, TransactionReceiptWithDecodedLogs, TxDataPayable } from 'ethe
 import * as _ from 'lodash';

 import { ForwarderContract } from '../../generated-wrappers/forwarder';
-
-import { constants } from './constants';
-import { formatters } from './formatters';
-import { LogDecoder } from './log_decoder';
-import { MarketSellOrders } from './types';
+import { artifacts } from '../../src/artifacts';

 export class ForwarderWrapper {
    private readonly _web3Wrapper: Web3Wrapper;
@@ -61,7 +60,11 @@ export class ForwarderWrapper {
    constructor(contractInstance: ForwarderContract, provider: Provider) {
        this._forwarderContract = contractInstance;
        this._web3Wrapper = new Web3Wrapper(provider);
-        this._logDecoder = new LogDecoder(this._web3Wrapper);
+        this._logDecoder = new LogDecoder(this._web3Wrapper, {
+            ...artifacts,
+            ...tokensArtifacts,
+            ...protocolArtifacts,
+        });
    }
    public async marketSellOrdersWithEthAsync(
        orders: SignedOrder[],
--- a/contracts/extensions/tsconfig.json
+++ b/contracts/extensions/tsconfig.json
@@ -0,0 +1,17 @@
+{
+    "extends": "../../tsconfig",
+    "compilerOptions": {
+        "outDir": "lib",
+        "rootDir": ".",
+        "resolveJsonModule": true
+    },
+    "include": ["./src/**/*", "./test/**/*", "./generated-wrappers/**/*"],
+    "files": [
+        "./generated-artifacts/BalanceThresholdFilter.json",
+        "./generated-artifacts/DutchAuction.json",
+        "./generated-artifacts/Forwarder.json",
+        "./generated-artifacts/OrderMatcher.json",
+        "./generated-artifacts/OrderValidator.json"
+    ],
+    "exclude": ["./deploy/solc/solc_bin"]
+}
--- a/contracts/extensions/tslint.json
+++ b/contracts/extensions/tslint.json
@@ -0,0 +1,6 @@
+{
+    "extends": ["@0x/tslint-config"],
+    "rules": {
+        "custom-no-magic-numbers": false
+    }
+}
--- a/contracts/interfaces/CHANGELOG.json
+++ b/contracts/interfaces/CHANGELOG.json
@@ -0,0 +1,20 @@
+[
+    {
+        "timestamp": 1547040760,
+        "version": "1.0.3",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1544741676,
+        "version": "1.0.2",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    }
+]
--- a/contracts/interfaces/CHANGELOG.md
+++ b/contracts/interfaces/CHANGELOG.md
@@ -0,0 +1,14 @@
+<!--
+changelogUtils.file is auto-generated using the monorepo-scripts package. Don't edit directly.
+Edit the package's CHANGELOG.json file only.
+-->
+
+CHANGELOG
+
+## v1.0.3 - _January 9, 2019_
+
+    * Dependencies updated
+
+## v1.0.2 - _December 13, 2018_
+
+    * Dependencies updated
--- a/contracts/interfaces/README.md
+++ b/contracts/interfaces/README.md
@@ -0,0 +1,72 @@
+## Contract interfaces
+
+Smart contract interfaces of the 0x protocol.
+
+## Usage
+
+Contracts that make up and interact with version 2.0.0 of the protocol can be found in the [contracts](./contracts) directory. The contents of this directory are broken down into the following subdirectories:
+
+*   [protocol](./contracts/protocol)
+    *   This directory contains the contract interfaces that make up version 2.0.0. A full specification can be found [here](https://github.com/0xProject/0x-protocol-specification/blob/master/v2/v2-specification.md).
+
+## Bug bounty
+
+A bug bounty for the 2.0.0 contracts is ongoing! Instructions can be found [here](https://0xproject.com/wiki#Bug-Bounty).
+
+## Contributing
+
+We strongly recommend that the community help us make improvements and determine the future direction of the protocol. To report bugs within this package, please create an issue in this repository.
+
+For proposals regarding the 0x protocol's smart contract architecture, message format, or additional functionality, go to the [0x Improvement Proposals (ZEIPs)](https://github.com/0xProject/ZEIPs) repository and follow the contribution guidelines provided therein.
+
+Please read our [contribution guidelines](../../CONTRIBUTING.md) before getting started.
+
+### Install Dependencies
+
+If you don't have yarn workspaces enabled (Yarn < v1.0) - enable them:
+
+```bash
+yarn config set workspaces-experimental true
+```
+
+Then install dependencies
+
+```bash
+yarn install
+```
+
+### Build
+
+To build this package and all other monorepo packages that it depends on, run the following from the monorepo root directory:
+
+```bash
+PKG=@0x/contracts-interfaces yarn build
+```
+
+Or continuously rebuild on change:
+
+```bash
+PKG=@0x/contracts-interfaces yarn watch
+```
+
+### Clean
+
+```bash
+yarn clean
+```
+
+### Lint
+
+```bash
+yarn lint
+```
+
+### Run Tests
+
+```bash
+yarn test
+```
+
+#### Testing options
+
+Contracts testing options like coverage, profiling, revert traces or backing node choosing - are described [here](../TESTING.md).
--- a/contracts/interfaces/compiler.json
+++ b/contracts/interfaces/compiler.json
@@ -0,0 +1,35 @@
+{
+    "artifactsDir": "./generated-artifacts",
+    "contractsDir": "./contracts",
+    "compilerSettings": {
+        "optimizer": {
+            "enabled": true,
+            "runs": 1000000
+        },
+        "outputSelection": {
+            "*": {
+                "*": [
+                    "abi",
+                    "evm.bytecode.object",
+                    "evm.bytecode.sourceMap",
+                    "evm.deployedBytecode.object",
+                    "evm.deployedBytecode.sourceMap"
+                ]
+            }
+        }
+    },
+    "contracts": [
+        "IAssetData",
+        "IAssetProxy",
+        "IAuthorizable",
+        "IAssetProxyDispatcher",
+        "IExchange",
+        "IExchangeCore",
+        "IMatchOrders",
+        "ISignatureValidator",
+        "ITransactions",
+        "IValidator",
+        "IWallet",
+        "IWrapperFunctions"
+    ]
+}
--- a/packages/contracts/contracts/protocol/AssetProxy/interfaces/IAssetData.sol
+++ b/packages/contracts/contracts/protocol/AssetProxy/interfaces/IAssetData.sol
@@ -17,7 +17,8 @@
 */

 // solhint-disable
-pragma solidity 0.4.24;
+pragma solidity ^0.4.24;
+pragma experimental ABIEncoderV2;


 // @dev Interface of the asset proxy's assetData.
@@ -26,15 +27,18 @@ pragma solidity 0.4.24;
 interface IAssetData {

    function ERC20Token(address tokenContract)
-        external
-        pure;
+        external;
    
    function ERC721Token(
        address tokenContract,
-        uint256 tokenId,
-        bytes receiverData
+        uint256 tokenId
    )
-        external
-        pure;
+        external;
+
+    function MultiAsset(
+        uint256[] amounts,
+        bytes[] nestedAssetData
+    )
+        external;
    
 }
--- a/packages/contracts/contracts/protocol/AssetProxy/interfaces/IAssetProxy.sol
+++ b/packages/contracts/contracts/protocol/AssetProxy/interfaces/IAssetProxy.sol
@@ -16,7 +16,7 @@

 */

-pragma solidity 0.4.24;
+pragma solidity ^0.4.24;

 import "./IAuthorizable.sol";

--- a/packages/contracts/contracts/protocol/AssetProxy/interfaces/IAuthorizable.sol
+++ b/packages/contracts/contracts/protocol/AssetProxy/interfaces/IAuthorizable.sol
@@ -16,9 +16,9 @@

 */

-pragma solidity 0.4.24;
+pragma solidity ^0.4.24;

-import "../../../utils/Ownable/IOwnable.sol";
+import "@0x/contracts-utils/contracts/utils/Ownable/IOwnable.sol";


 contract IAuthorizable is
--- a/packages/contracts/contracts/protocol/Exchange/interfaces/IAssetProxyDispatcher.sol
+++ b/packages/contracts/contracts/protocol/Exchange/interfaces/IAssetProxyDispatcher.sol
@@ -16,7 +16,7 @@

 */

-pragma solidity 0.4.24;
+pragma solidity ^0.4.24;


 contract IAssetProxyDispatcher {
--- a/packages/contracts/contracts/protocol/Exchange/interfaces/IExchange.sol
+++ b/packages/contracts/contracts/protocol/Exchange/interfaces/IExchange.sol
@@ -16,7 +16,7 @@

 */

-pragma solidity 0.4.24;
+pragma solidity ^0.4.24;
 pragma experimental ABIEncoderV2;

 import "./IExchangeCore.sol";
--- a/packages/contracts/contracts/protocol/Exchange/interfaces/IExchangeCore.sol
+++ b/packages/contracts/contracts/protocol/Exchange/interfaces/IExchangeCore.sol
@@ -16,11 +16,11 @@

 */

-pragma solidity 0.4.24;
+pragma solidity ^0.4.24;
 pragma experimental ABIEncoderV2;

-import "../libs/LibOrder.sol";
-import "../libs/LibFillResults.sol";
+import "@0x/contracts-libs/contracts/libs/LibOrder.sol";
+import "@0x/contracts-libs/contracts/libs/LibFillResults.sol";


 contract IExchangeCore {
--- a/packages/contracts/contracts/protocol/Exchange/interfaces/IMatchOrders.sol
+++ b/packages/contracts/contracts/protocol/Exchange/interfaces/IMatchOrders.sol
@@ -15,11 +15,11 @@
  limitations under the License.

 */
-pragma solidity 0.4.24;
+pragma solidity ^0.4.24;
 pragma experimental ABIEncoderV2;

-import "../libs/LibOrder.sol";
-import "../libs/LibFillResults.sol";
+import "@0x/contracts-libs/contracts/libs/LibOrder.sol";
+import "@0x/contracts-libs/contracts/libs/LibFillResults.sol";


 contract IMatchOrders {
--- a/packages/contracts/contracts/protocol/Exchange/interfaces/ISignatureValidator.sol
+++ b/packages/contracts/contracts/protocol/Exchange/interfaces/ISignatureValidator.sol
@@ -16,7 +16,7 @@

 */

-pragma solidity 0.4.24;
+pragma solidity ^0.4.24;


 contract ISignatureValidator {
--- a/packages/contracts/contracts/protocol/Exchange/interfaces/ITransactions.sol
+++ b/packages/contracts/contracts/protocol/Exchange/interfaces/ITransactions.sol
@@ -15,7 +15,7 @@
  limitations under the License.

 */
-pragma solidity 0.4.24;
+pragma solidity ^0.4.24;


 contract ITransactions {
--- a/packages/contracts/contracts/protocol/Exchange/interfaces/IValidator.sol
+++ b/packages/contracts/contracts/protocol/Exchange/interfaces/IValidator.sol
@@ -16,7 +16,7 @@

 */

-pragma solidity 0.4.24;
+pragma solidity ^0.4.24;


 contract IValidator {
--- a/packages/contracts/contracts/protocol/Exchange/interfaces/IWallet.sol
+++ b/packages/contracts/contracts/protocol/Exchange/interfaces/IWallet.sol
@@ -16,7 +16,7 @@

 */

-pragma solidity 0.4.24;
+pragma solidity ^0.4.24;


 contract IWallet {
--- a/packages/contracts/contracts/protocol/Exchange/interfaces/IWrapperFunctions.sol
+++ b/packages/contracts/contracts/protocol/Exchange/interfaces/IWrapperFunctions.sol
@@ -16,11 +16,11 @@

 */

-pragma solidity 0.4.24;
+pragma solidity ^0.4.24;
 pragma experimental ABIEncoderV2;

-import "../libs/LibOrder.sol";
-import "../libs/LibFillResults.sol";
+import "@0x/contracts-libs/contracts/libs/LibOrder.sol";
+import "@0x/contracts-libs/contracts/libs/LibFillResults.sol";


 contract IWrapperFunctions {
--- a/contracts/interfaces/package.json
+++ b/contracts/interfaces/package.json
@@ -0,0 +1,57 @@
+{
+    "name": "@0x/contracts-interfaces",
+    "version": "1.0.3",
+    "engines": {
+        "node": ">=6.12"
+    },
+    "description": "Smart contract interfaces of 0x protocol",
+    "main": "lib/src/index.js",
+    "scripts": {
+        "build": "yarn pre_build && tsc -b",
+        "build:ci": "yarn build",
+        "pre_build": "run-s compile generate_contract_wrappers",
+        "compile": "sol-compiler",
+        "watch": "sol-compiler -w",
+        "clean": "shx rm -rf lib generated-artifacts generated-wrappers",
+        "generate_contract_wrappers": "abi-gen --abis  ${npm_package_config_abis} --template ../../node_modules/@0x/abi-gen-templates/contract.handlebars --partials '../../node_modules/@0x/abi-gen-templates/partials/**/*.handlebars' --output generated-wrappers --backend ethers",
+        "lint": "tslint --format stylish --project . --exclude ./generated-wrappers/**/* --exclude ./generated-artifacts/**/* --exclude **/lib/**/* && yarn lint-contracts",
+        "lint-contracts": "solhint -c ../.solhint.json contracts/**/**/**/**/*.sol"
+    },
+    "config": {
+        "abis": "generated-artifacts/@(IAssetData|IAssetProxy|IAuthorizable|IAssetProxyDispatcher|IExchange|IExchangeCore|IMatchOrders|ISignatureValidator|ITransactions|IValidator|IWallet|IWrapperFunctions).json"
+    },
+    "repository": {
+        "type": "git",
+        "url": "https://github.com/0xProject/0x-monorepo.git"
+    },
+    "license": "Apache-2.0",
+    "bugs": {
+        "url": "https://github.com/0xProject/0x-monorepo/issues"
+    },
+    "homepage": "https://github.com/0xProject/0x-monorepo/contracts/interfaces/README.md",
+    "devDependencies": {
+        "@0x/abi-gen": "^1.0.20",
+        "@0x/sol-compiler": "^2.0.0",
+        "@0x/tslint-config": "^2.0.0",
+        "npm-run-all": "^4.1.2",
+        "shx": "^0.2.2",
+        "solhint": "^1.4.1",
+        "tslint": "5.11.0",
+        "typescript": "3.0.1",
+        "yargs": "^10.0.3"
+    },
+    "dependencies": {
+        "@0x/base-contract": "^3.0.11",
+        "@0x/contracts-libs": "^1.0.3",
+        "@0x/contracts-utils": "^1.0.3",
+        "@0x/types": "^1.5.0",
+        "@0x/typescript-typings": "^3.0.6",
+        "@0x/utils": "^2.1.1",
+        "@0x/web3-wrapper": "^3.2.2",
+        "ethereum-types": "^1.1.4",
+        "lodash": "^4.17.5"
+    },
+    "publishConfig": {
+        "access": "public"
+    }
+}
--- a/contracts/interfaces/src/artifacts/index.ts
+++ b/contracts/interfaces/src/artifacts/index.ts
@@ -0,0 +1,29 @@
+import { ContractArtifact } from 'ethereum-types';
+
+import * as IAssetData from '../../generated-artifacts/IAssetData.json';
+import * as IAssetProxy from '../../generated-artifacts/IAssetProxy.json';
+import * as IAssetProxyDispatcher from '../../generated-artifacts/IAssetProxyDispatcher.json';
+import * as IAuthorizable from '../../generated-artifacts/IAuthorizable.json';
+import * as IExchange from '../../generated-artifacts/IExchange.json';
+import * as IExchangeCore from '../../generated-artifacts/IExchangeCore.json';
+import * as IMatchOrders from '../../generated-artifacts/IMatchOrders.json';
+import * as ISignatureValidator from '../../generated-artifacts/ISignatureValidator.json';
+import * as ITransactions from '../../generated-artifacts/ITransactions.json';
+import * as IValidator from '../../generated-artifacts/IValidator.json';
+import * as IWallet from '../../generated-artifacts/IWallet.json';
+import * as IWrapperFunctions from '../../generated-artifacts/IWrapperFunctions.json';
+
+export const artifacts = {
+    IAssetProxyDispatcher: IAssetProxyDispatcher as ContractArtifact,
+    IAuthorizable: IAuthorizable as ContractArtifact,
+    IExchange: IExchange as ContractArtifact,
+    IExchangeCore: IExchangeCore as ContractArtifact,
+    IMatchOrders: IMatchOrders as ContractArtifact,
+    ISignatureValidator: ISignatureValidator as ContractArtifact,
+    ITransactions: ITransactions as ContractArtifact,
+    IWrapperFunctions: IWrapperFunctions as ContractArtifact,
+    IAssetData: IAssetData as ContractArtifact,
+    IAssetProxy: IAssetProxy as ContractArtifact,
+    IValidator: IValidator as ContractArtifact,
+    IWallet: IWallet as ContractArtifact,
+};
--- a/contracts/interfaces/src/index.ts
+++ b/contracts/interfaces/src/index.ts
@@ -0,0 +1,2 @@
+export * from './artifacts';
+export * from './wrappers';
--- a/contracts/interfaces/src/wrappers/index.ts
+++ b/contracts/interfaces/src/wrappers/index.ts
@@ -0,0 +1,12 @@
+export * from '../../generated-wrappers/i_asset_data';
+export * from '../../generated-wrappers/i_asset_proxy';
+export * from '../../generated-wrappers/i_asset_proxy_dispatcher';
+export * from '../../generated-wrappers/i_exchange';
+export * from '../../generated-wrappers/i_exchange_core';
+export * from '../../generated-wrappers/i_match_orders';
+export * from '../../generated-wrappers/i_signature_validator';
+export * from '../../generated-wrappers/i_transactions';
+export * from '../../generated-wrappers/i_authorizable';
+export * from '../../generated-wrappers/i_wrapper_functions';
+export * from '../../generated-wrappers/i_validator';
+export * from '../../generated-wrappers/i_wallet';
--- a/contracts/interfaces/tsconfig.json
+++ b/contracts/interfaces/tsconfig.json
@@ -0,0 +1,24 @@
+{
+    "extends": "../../tsconfig",
+    "compilerOptions": {
+        "outDir": "lib",
+        "rootDir": ".",
+        "resolveJsonModule": true
+    },
+    "include": ["./src/**/*", "./generated-wrappers/**/*"],
+    "files": [
+        "./generated-artifacts/IAssetData.json",
+        "./generated-artifacts/IAssetProxy.json",
+        "./generated-artifacts/IAuthorizable.json",
+        "./generated-artifacts/IAssetProxyDispatcher.json",
+        "./generated-artifacts/IExchange.json",
+        "./generated-artifacts/IExchangeCore.json",
+        "./generated-artifacts/IMatchOrders.json",
+        "./generated-artifacts/ISignatureValidator.json",
+        "./generated-artifacts/ITransactions.json",
+        "./generated-artifacts/IValidator.json",
+        "./generated-artifacts/IWallet.json",
+        "./generated-artifacts/IWrapperFunctions.json"
+    ],
+    "exclude": ["./deploy/solc/solc_bin"]
+}
--- a/contracts/interfaces/tslint.json
+++ b/contracts/interfaces/tslint.json
@@ -0,0 +1,6 @@
+{
+    "extends": ["@0x/tslint-config"],
+    "rules": {
+        "custom-no-magic-numbers": false
+    }
+}
--- a/contracts/libs/CHANGELOG.json
+++ b/contracts/libs/CHANGELOG.json
@@ -0,0 +1,20 @@
+[
+    {
+        "timestamp": 1547040760,
+        "version": "1.0.3",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1544741676,
+        "version": "1.0.2",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    }
+]
--- a/Show More
+++ b/Show More