Shadows

Shadows is a decentralized synthetic asset issuance protocol built on Substrate. The value of these synthetic assets is underpinned by DOWS, and as long as DOWS is locked in a smart contract, synthetic assets can be issued.

Unique debt pool design mechanism. Trading of synthetic assets is essentially a transfer between debts. Smart contracts automatically execute the conversion of a synthetic asset to another synthetic asset without an order book, without counterparties, and without the problems of liquidity and trading slippage.

DApps

• https://reactor.shadows.link

Usage and requirements

For tests (in javascript)

Install the dependencies for the project using npm

$ npm i

To run the tests:

$ npm test

Contracts

• ExchangeRates.sol: A key value store (bytes4 -> uint) of currency exchange rates, all priced in USD. Understands the concept of whether a rate is stale (as in hasn't been updated frequently enough), and only allows a single annointed oracle address to do price updates.
• ExternStateToken.sol: The concept of an ERC20 token which stores its allowances and balances outside of the contract for upgradability.
• FeePool.sol: Understands fee information for Shadows. As users transact, their fees are kept in 0xfeefeefee... and stored in xUSDs. Allows users to claim fees they're entitled to.
• Shadows.sol: Has a list of Synths and understands issuance data for users to be able to mint and burn Synths.
• ShadowsEscrow.sol: During the crowdsale, users were asked to escrow their Havvens to insulate against price shocks on the token. Users are able to unlock their DOWS on a vesting schedule.
• Depot.sol: Allows users to exchange ETH for xUSD and DOWS (has not yet been updated for multicurrency).
• LimitedSetup.sol: Some contracts have actions that should only be able to be performed during a specific limited setup period. After this period elapses, any functions using the onlyDuringSetup modifier should no longer be callable.
• Migrations.sol: Truffle's migrations contract.
• Synth.sol: Synth token contract which remits fees on transfers, and directs the Shadows contract to do exchanges when appropriate.
• SynthAirdropper.sol: Used to optimise gas during our initial airdrop of Synth.
• Owned.sol: Allows us to leverage the concept of a contract owner that is specially priviledged and can perform certain actions.
• Pausable.sol: Implements the concept of a pause button on a contract. Methods that should be paused use a particular modifier.
• Proxy.sol: Our proxy contracts which forward all calls they receive to their target. Events are always emitted at the proxy, not within the target, even if you call the target directly.
• Proxyable.sol: Implemented on a contract so it can be the target of a proxy contract.
• SafeDecimalMath.sol: Safe math + decimal math. Using _dec on an operation makes it operate "on decimals" by either dividing out the extra UNIT after a multiplication, or multiplying it in before a division.
• SelfDestructible.sol: Allows an owner of a contract to set a self destruct timer on it, then once the timer has expired, to kill the contract with selfdestruct.
• State.sol: Implements the concept of an associated contract which can be changed by the owner.
• TokenState.sol: Holds approval and balance information for tokens.