centre-tokens

Fiat tokens on the CENTRE network.

Setup

Requirements:

• Node 16.14.0
• Yarn

$ git clone [email protected]:centrehq/centre-tokens.git
$ cd centre-tokens
$ nvm use 16.14.0
$ npm i -g yarn       # Install yarn if you don't already have it
$ yarn install        # Install dependencies

Deployment

The deployment process is detailed on Confluence.

You will need 5 different hot keys (blacklister, deployer, master minter, owner, and proxy admin), and they should be funded (with 0.5-1 ETH) to pay for transactions. You can use ./scripts/create-account.js to create the keys.

Create a copy of the file config.js.example, and name it config.js. Create a copy of config.{env}.js.example for stg and prod by replacing env with the name of the environment e.g. config.stg.js. The config.js file holds values that are common whereas config.{env}.js holds environment specific values. Fill in the empty values. These file must not be checked into the repository. To prevent accidental check-ins, config.js, config.{env}.js and blacklist.txt are in .gitignore.

For mainnet, be sure to have a specified blacklist.txt file with a sanctions list from Compliance. As seen in blacklist.txt.example, addresses are split by new lines. You must blacklist the sanctions list at deployment time using the hot blacklister key (in config.js).

// Ensure that the ENV variable in config.js is set to stg or prod, which will 
// dictate which config.{env}.js file gets read during execution
yarn deployContracts --network {development, testnet, mainnet}
yarn blacklistSeed --network development

// When you deploy the contract for the first time, it will give you address for the FiatToken Proxy
// which you can use as the PROXY_CONTRACT_ADDRESS
// Ensure that PROXY_CONTRACT_ADDRESS and MINT_ALLOWANCE_UNITS
// are properly set in config.js and config.{env}.js respectively
yarn minters --network {development, testnet, mainnet}

// Only needed for mainnet, but feel free to simulate a local run on the dev network.
// This will move all five hot keys to cold.
yarn coldStorage --network {development, testnet, mainnet}

yarn verify --network {see here https://www.npmjs.com/package/truffle-plugin-verify}

Note that you may need to update truffle-config.js to have a verify attribute for the network you're testing. See Confluence for details.

Remember to save the config.js file in 1PW Wallets Org

• include the deployed contract addresses in the config file.

TypeScript type definition files for the contracts

To generate type definitions:

$ yarn compile && yarn typechain

Linting and Formatting

To check code for problems:

$ yarn typecheck      # Type-check TypeScript code
$ yarn lint           # Check JavaScript and TypeScript code
$ yarn lint --fix     # Fix problems where possible
$ yarn solhint        # Check Solidity code
$ yarn slither        # Run Slither

To auto-format code:

$ yarn fmt

Testing

First, make sure Ganache is running.

$ yarn ganache

Run all tests:

$ yarn test

To run tests in a specific file, run:

$ yarn test [path/to/file]

To run tests and generate test coverage, run:

$ yarn coverage

Contracts

The implementation uses 2 separate contracts - a proxy contract (FiatTokenProxy.sol) and an implementation contract (FiatToken.sol). This allows upgrading the contract, as a new implementation contact can be deployed and the Proxy updated to point to it.

FiatToken

The FiatToken offers a number of capabilities, which briefly are described below. There are more detailed design docs in the doc folder.

ERC20 compatible

The FiatToken implements the ERC20 interface.

Pausable

The entire contract can be frozen, in case a serious bug is found or there is a serious key compromise. No transfers can take place while the contract is paused. Access to the pause functionality is controlled by the pauser address.

Upgradable

A new implementation contract can be deployed, and the proxy contract will forward calls to the new contract. Access to the upgrade functionality is guarded by a proxyOwner address. Only the proxyOwner address can change the proxyOwner address.

Blacklist

The contract can blacklist certain addresses which will prevent those addresses from transferring or receiving tokens. Access to the blacklist functionality is controlled by the blacklister address.

Minting/Burning

Tokens can be minted or burned on demand. The contract supports having multiple minters simultaneously. There is a masterMinter address which controls the list of minters and how much each is allowed to mint. The mint allowance is similar to the ERC20 allowance - as each minter mints new tokens their allowance decreases. When it gets too low they will need the allowance increased again by the masterMinter.

Ownable

The contract has an Owner, who can change the owner, pauser, blacklister, or masterMinter addresses. The owner can not change the proxyOwner address.