Tapio Project

This project demonstrates a basic Hardhat use case. It comes with a sample contract, a test for that contract, and a script that deploys that contract.

Try running some of the following tasks:

npx hardhat help
npx hardhat test
REPORT_GAS=true npx hardhat test
npx hardhat node
npx hardhat run scripts/deploy.ts

Goerli Testnet Address:

constant: 0x07e70721C1737a9D410bcd038BA7e82e8BC19e2a
rETHRate: 0xf2dD62922B5f0cb2a72dAeda711018d6F56EEb17

tapETH: 0x0C68f684324551b4B6Ff6DFc6314655f8e7d761a
WTapETH: 0x31CcC35cbed56B6e8f01E8207B1302f009ABC27c

stETHSwap: 0x79106c599A6A320DFB0686513631a92fF8343b44
rETHSwap: 0x9719443a2BBb5AB61744C1B3C71C2E3527101a91

application: 0x44A54f1cc211cfCFfE8b83C22f44728F3Fa5004C

wETHAddress: '0xB4FBF271143F4FBf7B91A5ded31805e42b2208d6'
stETHAddress: '0x1643E812aE58766192Cf7D2Cf9567dF2C37e9B7F'
rETHAddress: '0x178e141a0e3b34152f73ff610437a7bf9b83267a'

rETH staking website: https://testnet.rocketpool.net/

Smart Contracts OVERVIEW

The main contracts of Tapio V1.5 are the following:

TapEth : contract of rebase token tapETH

WtapETH: contract of wrapped tapETH

StableAsset: contract of stableswap pool

StableAssetApplication: user contract interface for different stableSwap pools

Contract TapETH

The contract TapETH is upgradable and uses the interface IERC20.

Write Methodes

• proposeGovernance(address _governance)

  This function allows the current governance to set a new governance address.

• acceptGovernance(address _governance)

  This function allows the pending governance to be activated: to update the governance to the pending governance.

• addPool(address _pool)

  This function can be executed only by the governance to whitelist a stableSwap pool.

• removePool(address _pool)

  This function can be executed only by the governance to remove a whitelisted stableSwap pool.

• transferShares(address _recipient, uint256 _sharesAmount)

  This function allows the caller to transfer _sharesAmount shares of tapETH from his address to _recipient.

• transferSharesFrom(address _sender, address _recipient, uint256 _sharesAmount)

This function allows the spender to transfer _sharesAmount shares of tapETH from to _sender to _recipient.

• mintShares(address _account, uint256 _tokenAmount)

This function can be executed by a whitelisted stableSwap pool to mint _tokenAmount of tapETH for _account.

• burnShares(uint256 _tokenAmount)

This function allows the caller to burn _tokenAmount of tapETH.

• burnSharesFrom(address _account, uint256 _tokenAmount)

This function allows the spender to burn _tokenAmount of tapETH from the addresss _account.

View Methodes

• getTotalPooledEther()

  This function returns the total supply of tapETH (uint256).

• getTotalShares()

  This function returns the total shares of tapETH (uint256).

• getSharesByPooledEth(uint256_tapETHAmount)

This function returns the shares of tapETH (uint256) corresponding to _tapETHAmount of tapETH.

• getPooledEthByShares(uint256 _sharesAmount)

  This function returns the amount of tapETH (uint256) corresponding to `sharesAmount' shares of tapETH.

• setTotalSupply(uint256 _amount)

  This function can be only called by a whitelist stableSwap pool contract to increase the total supply of tapETH by _amount.

Contract WTapETH

The contract WTapETH is upgradable and inherits from the contract ERC20Permit.

Write Methodes

• wrap(uint256 _tapETHAmount)

This function allows the user to wrap _ tapETHAmount of tapETH that consisting in transferring _tapETHAmount of tapETH to the smart contract WTapETH and minting the corresponding shares amount in wtapETH.

• unwrap(uint256 _wtapETHAmount)

This function allows the user to unwrap _wtapETHAmount of wtapETH that consisting in burning wtapETHAmount of wtapETH and sending from the smart contract WTapETH to the caller the corresponding amount of tapETH.

View Methodes

• getWtapETHByTapETH(uint256 _tapETHAmount)

This function returns the amount of wtapETH that corresponds to _tapETHAmount of tapETH.

• getTapETHByWtapETH(uint256 _wtapETHAmount)

This function returns the amount of tapETH that corresponds to _wtapETHAmount of wtapETH.

• tapETHPerToken()

This function returns the amount of tapETH that corresponds to 1 wtapETH.

• tokensPerTapETH()

This function returns the amount of wtapETH that corresponds to 1 tapETH.

Contract StableAsset

The contract StableAsset is upgradable and inherits from the contract ReentrancyGuard.

Write Methodes

• mint(uint256[] calldata _amounts, uint256 _minMintAmount)

This function allows the user to provide liquidity in the different tokens of the pool to mint at least _wtapETHAmount of tapETH. The Logic of the function consists of :

1. update token balances
2. calculate the new D value
3. calculate delta D = new D - old D
4. calculate mintAmount = delta D - feeAmount = delta D * ( 1- mintFee)
5. revert if mintAmount < _minMintAmount
6. mint mintAmount of tapETH for the caller
7. increase the total supply of tapETH by feeAmount

• swap(uint256 _i, uint256 _j, uint256 _dx, uint256 _minDy)

This function allows the user to swap _dx amount of token index i to at least _minDy amount of token index j. The Logic of the function consists of:

1. update balance of token index i .
2. calculate the new balance of token index j: new y
3. calculate delta y = new y - old y
4. calculate outputAmount = delta y - feeAmount = delta y * ( 1- swapFee)
5. revert if outputAmount < _minDy
6. send outputAmount of token index j to the caller
7. increase the total supply of tapETH by feeAmount

• redeemProportion(uint256 _amount, uint256[] calldata _minRedeemAmounts)

This function allows the user to redeem _amount of tapETH in order to receive at least _minRedeemAmounts[i] of each token index i. The Logic of the function consists of:

1. calculate redeemAmount = _amount - feeAmount = amount * ( 1 - redeemFee).
2. for each token i :
   • calculate tokenAmount = balances[i] * redeemAmount / D
   • revert if tokenAmount < minRedeemAmounts[i]
   • send tokenAmount of token index i to the caller
3. update D = D - _amount
4. burn _amount of tapETH from the caller
5. increase the totalSupply of tapETH by feeAmount

• redeemSingle(uint256 _amount, uint256 _i, uint256 _minRedeemAmount)

This function allows the user to redeem _amount of tapETH in order to receive at least _minRedeemAmount of token index i. The Logic of the function consists of:

1. calculate redeemAmount = _amount - feeAmount = amount * ( 1 - redeemFee).
2. calculate the new amount of token i (new y ) for D = D - redeemAmount
3. calculate delta y = new y - old y
4. revert if delta y < _minRedeemAmount
5. send delta y of token index i to the caller
6. increase the total supply of tapETH by feeAmount

• redeemMulti(uint256[] calldata _amounts, uint256 _maxRedeemAmount)

This function allows the user to redeem at most _maxRedeemAmount of tapETH to receive _amouns[i] of each token index i. The Logic of the function consists of:

1. update balance of each token index i .
2. calculate the new D
3. calculate delta D = new D - old D
4. calculate redeemAmount = delta D + feeAmount = delta D * ( 1 + redeemFee)
5. revert if redeemAmount > _maxRedeemAmount
6. for each token index i, send _amounts[i] to the caller
7. increase the total supply of tapETH by feeAmount

functions to be executed only by the governance:

• proposeGovernance(address _governance)

  This function allows the current governance to set a new governance address.

• acceptGovernance(address _governance)

  This function allows the pending governance to be activated: to update the governance to the pending governance.

• setMintFee(uint256 _mintFee)

This function allows the governance to update the mintFee.

• setSwapFee(uint256 _swapFee)

This function allows the governance to update the swapFee.

• setRedeemFee(uint256 _redeemFee)

This function allows the governance to update the redeemFee.

• pause()

This function allows the governance to pause the mint, swap and redeem function.

• unpause()

This function allows the governance to unpause the mint, swap and redeem function.

• setAdmin(address _account, bool _allowed)

This function allows the governance to add an admin if _allowed is true or to remove an admin if _allowed is false.

• updateA(uint256 _futureA, uint256 _futureABlock)

This function allows the governance to update the value of A to _futureA from the block _futureABlock.

Write Methodes

• getA()

This function returns the current value of A.

• getMintAmount(uint256[] calldata _amounts)

This function returns (uint256 mintAmount, uint256 fee) where mintAmount is the amount of tapETH to mint for the user, and fee is the mint fee.

• getSwapAmount(uint256 _i, uint256 _j, uint256 _dx)

This function returns (uint256 amount, uint256 fee) where amount is the output amount in token of index j to send to the user, and fee is the swap fee.

• getRedeemProportionAmount( uint256 _amount)

This function returns (uint256[] amounts, uint256 fee) where amounts[i] is the output amount in token of index i to send to the user, and fee is the redeem fee.

• getRedeemSingleAmount(uint256 _amount, uint256 _i)

This function returns (uint256 amount, uint256 fee) where amount is the output amount in token of index i to send to the user, and fee is the redeem fee.

• getRedeemMultiAmount(uint256[] calldata _amounts)

This function returns (uint256 amount, uint256 fee) where amount is the amount of tapETH to redeem and fee is the redeem fee.

Contract StableAssetApplication

The contract StableAssetApplication is upgradable and inherits from the contract ReentrancyGuard.

Write Methodes

• mint(StableAsset _pool, uint256[] calldata _amounts, uint256 _minMintAmount )

This function allows the user to provide liquidity in the different tokens of the pool _pool to mint at least _wtapETHAmount of tapETH.

• swap(StableAsset _pool, uint256 _i, uint256 _j, uint256 _dx, uint256 _minDy)

This function allows the user to swap _dx amount of token index i to at least _minDy amount of token index j using the pool _pool.

• redeemProportion(StableAsset _pool, uint256 _amount, uint256[] calldata _minRedeemAmounts)

This function allows the user to redeem _amount of tapETH from the pool _pool in order to receive at least _minRedeemAmounts[i] of each token index i .

• redeemSingle(StableAsset _pool, uint256 _amount, uint256 _i, uint256 _minRedeemAmount)

This function allows the user to redeem _amount of tapETH from the pool _pool in order to receive at least _minRedeemAmount of token index i.

• swapCrossPool(StableAsset _sourcePool, StableAsset _destPool, address _sourceToken, address _destToken, uint256 _amount, uint256 _minSwapAmount)

This function allows the user to swap _amount amount of token _sourceToken from the pool _sourcePool to at least _minSwapAmount amount of token _destToken from the pool _destPool.