NFTFairTreasury

The treasury contract serves as a central entity for collecting payment and sales revenue generated from vaults. This design is intended such that users would send at most one approve() call for one ERC20 token that can be spent across all vaults on the NFTFair platform.

To ensure the protocol does not drain the user's allowance without explicit approval, the collectPayment() method requires an EIP712 Signature, indicating the amount of specified tokens to be spent by an authorized address.

The structure of the EIP712 Message (similarly based on EIP 2612) is the following:

Permit: [
    { name: 'owner', type: 'address' },
    { name: 'spender', type: 'address' },
    { name: 'token', type: 'address' },
    { name: 'value', type: 'uint256' },
    { name: 'nonce', type: 'uint256' },
    { name: 'deadline', type: 'uint256' },
],

Parameter	Description
owner	The owner of the token. This is most likely the user's address
spender	The authorized spender. This is most likely the vault's address
token	The address of the ERC20 token to be spent
value	The payment amount
nonce	The user's transaction count in the Treasury contract
deadline	Transaction reverts at block.timestamp > deadline

In the future, the protocol may set a fee upon payment collection, using basis points. This value is given a ceiling of 3000. In other words. the protocol can not set a fee higher than 30%.

Last but not least, the protocol has the ability to exempt fees or configure a custom fee percentage for a specified spender. If an address is neither exempt nor assigned with a custom basis point, the Treasury will collect fee using the default BP.

collectPayment()

function collectPayment(
  address _buyer,
  address _token,
  uint256 _amount,
  uint256 _deadline,
  bytes calldata _signature
)

This function is called by the payee directly, to collect payment from the buyer.

Parameter	Type	Description
buyer	address	The owner of the token. This is most likely the user's address
token	address	The address of the ERC20 token to be spent
amount	uint256	The payment amount
deadline	uint256	Transaction reverts at block.timestamp > deadline
signature	bytes	The user signed EIP712 message

setNewBp

function setNewBp(uint256 _newBp)

Sets a new default BP. Requires onlyOwner()

Parameter	Type	Description
New BP	uint256	REVERTS > 3000

setAddressBp

function setAddressBp(address _spender, uint256 _newBp)

Specifies a custom BP for _spender. Requires onlyOwner()

Parameter	Type	Description
Spender	address	This is most likely the vault's address.
New BP	uint256	REVERTS > 3000

toggleAddressExemption

function toggleAddressExemption(address _spender)

Exempts/Unexempts _spender from paying fees. Requires onlyOwner()

Parameter	Type	Description
Spender	address	This is most likely the vault's address.

recoverERC20()

function recoverERC20(
  address _recipient,
  address _token,
  uint256 _amount
)

Withdraws the protocol revenue. Requires onlyOwner().

Parameter	Type	Description
recipient	address	The recipient address
token	address	The address of the ERC20 token
amount	uint256	The amount to withdraw

getFeeMultiplier()

function getFeeMultiplier(address _spender) public view returns (uint256 multiplier)

Returns the BP value for a specified _spender.