contracts

Contracts

Smart contracts that implement the 0x protocol. Addresses of the deployed contracts can be found here.

Usage

Contracts that make up and interact with version 2.0.0 of the protocol can be found in the contracts directory. The contents of this directory are broken down into the following subdirectories:

• protocol
  • This directory contains the contracts that make up version 2.0.0. A full specification can be found here.
• extensions
  • This directory contains contracts that interact with the 2.0.0 contracts and will be used in production, such as the Forwarder contract.
• examples
  • This directory contains example implementations of contracts that interact with the protocol but are not intended for use in production. Examples include filter contracts, a Wallet contract, and a Validator contract, among others.
• tokens
  • This directory contains implementations of different tokens and token standards, including wETH, ZRX, ERC20, and ERC721.
• multisig
  • This directory contains the Gnosis MultiSigWallet and a custom extension that adds a timelock to transactions within the MultiSigWallet.
• utils
  • This directory contains libraries and utils that are shared across all of the other directories.
• test
  • This directory contains mocks and other contracts that are used solely for testing contracts within the other directories.

Bug bounty

A bug bounty for the 2.0.0 contracts is ongoing! Instructions can be found here.

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) repository and follow the contribution guidelines provided therein.

Please read our contribution guidelines before getting started.

Install Dependencies

If you don't have yarn workspaces enabled (Yarn < v1.0) - enable them:

yarn config set workspaces-experimental true

Then install dependencies

yarn install

Build

To build this package and all other monorepo packages that it depends on, run the following from the monorepo root directory:

PKG=contracts yarn build

Or continuously rebuild on change:

PKG=contracts yarn watch

Clean

yarn clean

Lint

yarn lint

Run Tests

yarn test

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 instance. In order to run the tests against Geth, first follow the instructions in the README for the devnet package to start the devnet Geth node. Then run:

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.

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.