TrueUSD

This repository contains the TrueUSD ERC20 contract and related contracts.

The Contracts

This is a high-level overview of the contracts. For more specifics, see the relevant .sol files.

modularERC20/...

These contracts are inspired by and roughly equivalent to the corresponding ERC20 token contracts from OpenZeppelin. The main difference is that they keep track of balances and allowances by using separate contracts (BalanceSheet.sol and AllowanceSheet.sol) instead of mappings in their own storage.

Admins/...

TokenController.sol

This contract is the owner of TrueUSD.sol. Consists of an Owner key, Mint Pause Keys, Mint Key, and Mint Ratify Keys. It's also responsible for configuring constants and upgrading the token contract

MultiSigOwner.sol

This contract is the owner of TokenController.sol. It turns every function that only the owner can access into a multisig function that requires 2/3 approvals.

Proxy/...

ProxyStorage.sol

Storage layout of TrueUSD. Makes upgrades safer.

HasOwner.sol

Our own implementation of Claimable Contract.

BurnableTokenWithBounds.sol

This limits the minimum and maximum number of tokens that can be burned (redeemed) at once.

CompliantToken.sol

This ensures that only users who have passed a KYC/AML check can receive newly minted tokens. It also allows for blacklisting of bad actors in accordance with the TrueCoin Terms of Use.

DepositToken.sol

Allow users to register deposit addresses.

GasRefundToken.sol

Enable transfer and mint methods to be sponsored. Reduce gas cost of transfer and mint.

TrueUSD.sol

This is the top-level ERC20 contract tying together all the previously mentioned functionality.

Upgrade Process

There are three main parts to the system of smart contracts. TrueUSD Token, TokenController, and MultisigOwner. Each contract will sit behind a delegate proxy contract. So to upgrade, the admin needs to point the implementation in the delegate proxy to a new instance.

TokenController is the owner of TrueUSD and the also the proxyOwner of TrueUSD proxy Multisig is the owner of TokenController and the also the proxyOwner of TokenController proxy. Multisig is also the proxyOwner of its own proxy.

Testing

Initialize the registry submodule in the root directory:

git submodule init && git submodule update

To run the tests and generate a code coverage report:

npm install
npm test

Contract Structure

├── modularERC20  
│   ├── AllowanceSheet         
│   ├── BalanceSheet        
│   ├── ModularBasicToken        
│   ├── ModularStandardToken        
│   ├── ModularBurnableToken        
│   └── ModularMintableToken                
├── Admin                 
│   ├── TokenController        
│   └── MultisigOwner               
├── Proxy
│   ├── Proxy        
│   ├── UpgradeabilityProxy        
│   └── OwnedUpgradeabilityProxy               
├── utilities
│   ├── FastPauseMints        
│   └── FastPauseTrueUSD               
├── ProxyStorage
├── HasOwner
├── BurnableTokenWithBounds
├── CompliantToken
├── RedeemableToken
├── DepositToken
├── GasRefundToken
├── TrueUSD

Other Information

Description	URL
Etherscan Page	https://etherscan.io/token/0x8dd5fbce2f6a956c3022ba3663759011dd51e73e
Coinmarketcap	https://coinmarketcap.com/currencies/true-usd/
TrueUSD’s Terms of Use	https://www.trusttoken.com/terms-of-use/

Social Links

Pages	URL
Website	https://www.trueusd.com/
Facebook	https://www.facebook.com/TrustToken/
Twitter	https://twitter.com/TrustToken
Telegram	https://t.me/joinchat/HihkMkTja1gIyBRM1J1_vg

Exchanges where TrueUSD is Traded

Exchanges	URL
Binance	https://www.binance.com/
Huobi	https://www.huobi.com/
Okex	https://www.okex.com/
Bittrex	https://bittrex.com
CoinTiger	https://www.cointiger.pro
Upbit	https://upbit.com/
HBUS	https://www.hbus.com/

rstormsf / trueUSD