Ez Staker Contracts

Ez-Staker permits hex holders to tokenize their stakes upon staking. Stakes are tokenized as ERC-721 tokens so they can be transfered and used in other contracts/protocols. To unstake one must only own the minted ERC-721 token. Once unstaked the token is burnt.

Docs

These docs are for anyone wanting to integrate their DApp with the Ez-Staker contracts. Ez-Staker is a smart contract building on top of the Hex contract so some Hex utilities are included in this repo / package as well.

1 Installation

npm i ez-staker-contracts

This will install a node package containing abis, addresses and specific javascript utility functions.

2 Contract Specs

2.1 HexTransferable.sol

This is the main contract that does the staking and collects the fee. This contract implements the standard IERC721Enumerable interface as documented here. The address for this contract can be found in utils under the attribute addresses[network].ezStaker

• function stake(uint256 totalAmount, uint256 stakeDays, uint192 expectedFee)

  This function stakes hex tokens for the msg.sender and mints an ERC-721 token for the msg.sender. The token ID is equal to stakesOpened before calling stake().

  In order for this function to complete successfully the following conditions must be met:

  • the msg.sender must have a hex balance equal to or greater than totalAmount
  • the msg.sender must have approved the contract address to spend an amount of hex greater than or equal to totalAmount
  • expectedFee must match the current fee of the contract.

  The expected fee is also passed as a parameter to avoid a race condition where the owner changes the fee before a msg.sender stakes. This would potentially mean taking a different cut then the msg.sender expected upon sending his transaction. The creation of new stakes may be prevented by the owner by setting the fee to a 100%.

  The fee is deducted from the totalAmount. If the fee is 1% for example and the stakeAmount is 800 HEX the contract will only stake 792 HEX. The totalAmount (minus the fee) and the stakeDays are then passed to the Hex contracts stakeStart function.

• function unstake(uint stakeId)

  This function ends the stake and sends the resulting hex to the unstaker.

  In order for this function to complete successfully the following condition must be met:

  • The msg.sender must be the owner of the ERC-721 with a token ID matching stakeId

  The unstake function can be called at anytime by the owner of the token, even to perform an emergency unstake. All the staking rewards are returned to the caller. No fee is deducted upon unstaking.

• function fee() returns (uint192)

  This function returns the current fee. The fee is a UQInt128.64 to convert the fee to a float simply divide the fee by 2^64.

• event FeeSet(uint192 newFee)

  This event is emitted when the fee is changed. When the fee is set newFee will represent the new fee.

2.2 HexMock.sol

This contract is deployed to testnets as it is only for testing purposes. The address for this contract can be found in utils in the attribute addresses[network].hexMock. This mock only provides the basic ERC20 functions as well as the minimum necessary methods to simulate the mainnet Hex contract. Note this contract has 18 decimals instead of the 8 of mainnet Hex.

• function mint()

  mints 100 HEX for the msg.sender. Anyone can call this function an unlimited amount of times.

• function stake(uint256 newStakedHearts, uint256 newStakedDays)

  creates a dummy stake which can instantly be unstaked. The unstake value is 2% / day of the principal (non-compounding). stakeReward = stakeAmount * (1 + 0.2 * stakeDays)