fee-distribution.md

Fee Distribution

Contracts and wallets can be excluded from fees through the VaultFactoryUpgradable contract. The owner of the contract can add an address, along with a boolean representation of their exclusion from paying fees, to the setFeeExclusion function. This will emit a FeeExclusion event and update an internal mapping. This can then be queried by other contracts by performing a call along the lines of nftxVaultFactory.excludedFromFees(msg.sender).

Fees are charged and distributed when an NFT is minted, redeemed or swapped in an NFTX vault. If a user is excluded from fees in this manner then no fees will be send to the feeDistributor and no tokens will be transferred via the NFTX Vault contract.

This is used for NFTX zaps to allow for additional transactions to take place before, or instead of, incurring fees.

If fees are not excluded then:

• The amount of fee owed is determined by checking the vault fees that are assigned by it’s creator
• The fee is then transferred to the fee distributor contract attached to the vault
  • This distributor is required during initialisation and its implementation is validated.
  • At this point the fee amount is also sense checked
• The distributor contract then calls the distribute function, along with the corresponding vaultId that is calling it
• Distribution logic will vary depending on the contract that is implemented. The different distribution contracts should have ample documentation and commenting to understand.

Internal Attributes

distributionPaused

bool distributionPaused

Flags if distribution is currently paused

nftxVaultFactory

address nftxVaultFactory

Contract address of the NFTX Vault Factory contract.

lpStaking

address lpStaking

Contract address of the LP Staking contract.

treasury

address treasury

Contract address of the NFTX Treasury contract.

allocTotal

uint256 allocTotal

Total allocation points per vault.

feeReceivers

struct INFTXSimpleFeeDistributor.FeeReceiver[] feeReceivers

Array storage of fee receivers, accessed by index.

inventoryStaking

address inventoryStaking

Contract address of the NFTX Inventory Staking contract.

Events Emitted

UpdateTreasuryAddress

event UpdateTreasuryAddress(address newTreasury)

Emitted when the treasury address is updated.

Name	Type	Description
newTreasury	address	The new address for the treasury contract

UpdateLPStakingAddress

event UpdateLPStakingAddress(address newLPStaking)

Emitted when the LP Staking address is updated.

Name	Type	Description
newLPStaking	address	The new address for the LP Staking contract

UpdateInventoryStakingAddress

event UpdateInventoryStakingAddress(address newInventoryStaking)

Emitted when the Inventory Staking address is updated.

Name	Type	Description
newInventoryStaking	address	The new address for the Inventory Staking contract

UpdateNFTXVaultFactory

event UpdateNFTXVaultFactory(address factory)

Emitted when the NFTX Vault Factory address is updated.

Name	Type	Description
factory	address	The new address for the NFTX Vault Factory contract

PauseDistribution

event PauseDistribution(bool paused)

Emitted when this contract is paused or unpaused.

Name	Type	Description
paused	bool	Boolean value of if distribution has been paused (true) or unpaused (false)

AddFeeReceiver

event AddFeeReceiver(address receiver, uint256 allocPoint)

Emitted when a contract or non-contract receiver is added as a FeeReceiver.

Name	Type	Description
receiver	address	The address of the new fee recipient
allocPoint	uint256	The number of allocation points assigned to the receiver

UpdateFeeReceiverAlloc

event UpdateFeeReceiverAlloc(address receiver, uint256 allocPoint)

Emitted when a receiver's allocation is updated.

Name	Type	Description
receiver	address	The address of the updated fee recipient
allocPoint	uint256	The new number of allocation points assigned to the receiver

UpdateFeeReceiverAddress

event UpdateFeeReceiverAddress(address oldReceiver, address newReceiver)

Emitted when a receiver's address is updated.

Name	Type	Description
oldReceiver	address	The old address of the receiver
newReceiver	address	The new address of the receiver

RemoveFeeReceiver

event RemoveFeeReceiver(address receiver)

Emitted when a receiver's address is removed.

Name	Type	Description
receiver	address	The address of the receiver that was removed

Public Methods

SimpleFeeDistributor__init

function __SimpleFeeDistributor__init__(address _lpStaking, address _treasury) public

Initialiser for the fee distributor, setting relevant staking and treasury addresses.

Allows for upgradable deployment

Name	Type	Description
_lpStaking	address	Address of our LP Staking contract
_treasury	address	Address of our Treasury contract

distribute

function distribute(uint256 vaultId) external virtual

Distributes fees to receivers. All receivers will be iterated over to distribute their relative allocation of the total number of tokens.

The total balance of the token on the contract will be distributed.

Any dust balance remaining on the contract is transferred to the treasury.

_If distribution is paused or we have no receivers added (defined by allocTotal) then the entire token balance will be sent to the treasury.

When our receivers are set up by the contract owner they are assigned an allocPoint value that indicates the relative size of the allocation they will be eligible to receive. This is explained in greater depth on the addReceiver method.

The vault ID will determine the ERC20 token that will be transferred._

Name	Type	Description
vaultId	uint256	The vault ID that is to have its fees distributed

addReceiver

function addReceiver(uint256 _allocPoint, address _receiver, bool _isContract) external virtual

Adds a receiver to the fee distributor. If a contract receiver is added, then they must a call to receiveRewards as outlined in the _sendForReceiver function. The receiver is given an allocPoint value that defines their relative stake of the rewards.

_For the point allocation, if receiver A has 1 allocPoint and receiver B has 3 allocPoint then when rewards are distributed they will each receive a percentage based on the relative value.

For example, in this case receiver B would receive 75% of the rewards and receiver A would receive the remaining 25%._

Name	Type	Description
_allocPoint	uint256	The point allocation applied to the receiver
_receiver	address	The address of the receiver
_isContract	bool	Flag to determine if the receiver is a contract, rather than a wallet address

initializeVaultReceivers

function initializeVaultReceivers(uint256 _vaultId) external

Allows the NFTX Vault Factory contract caller to add a pool vault for LP Staking and, if an inventory staking address is set, then deploys an xToken for the vault.

Name	Type	Description
_vaultId	uint256	The NFTX vault ID

changeReceiverAlloc

function changeReceiverAlloc(uint256 _receiverIdx, uint256 _allocPoint) public virtual

Allows receiver allocation to be updated.

Safe math is not implemented, so calculations must not exceed uint256 boundaries for allocTotal.

Name	Type	Description
_receiverIdx	uint256	The index value of the feeReceiver in our internally stored array
_allocPoint	uint256	The new allocation for the receiver

changeReceiverAddress

function changeReceiverAddress(uint256 _receiverIdx, address _address, bool _isContract) public virtual

Allows receiver address and isContract state to be updated.

Name	Type	Description
_receiverIdx	uint256	The index value of the feeReceiver in our internally stored array
_address	address	The new address for the receiver
_isContract	bool	The new isContract boolean flag for the receiver

removeReceiver

function removeReceiver(uint256 _receiverIdx) external virtual

Removes the receiver from our internal array so that they will no longer be included in our fee distribution.

This removal changes the index order of the feeReceivers array by moving the last element to that of the removed value. External sources will need to reflect this change for future updates before making subsequent calls.

Name	Type	Description
_receiverIdx	uint256	The index value of the feeReceiver in our internally stored array

setTreasuryAddress

function setTreasuryAddress(address _treasury) public

Allows our treasury address to be updated.

Name	Type	Description
_treasury	address	Address of our new Treasury contract

setLPStakingAddress

function setLPStakingAddress(address _lpStaking) public

Allows our LP Staking address to be updated.

Name	Type	Description
_lpStaking	address	Address of our new LP Staking contract

setInventoryStakingAddress

function setInventoryStakingAddress(address _inventoryStaking) public

Allows our Inventory Staking address to be updated.

Name	Type	Description
_inventoryStaking	address	Address of our new Inventory Staking contract

setNFTXVaultFactory

function setNFTXVaultFactory(address _factory) external

Allows our NFTX Vault Factory address to be updated.

Name	Type	Description
_factory	address	Address of our new NFTX Vault Factory contract

pauseFeeDistribution

function pauseFeeDistribution(bool _pause) external

Allows our fee distribution system to be paused or unpaused.

Name	Type	Description
_pause	bool	A boolean representation of if the distribution should be paused

rescueTokens

function rescueTokens(address _address) external

Allows tokens to be rescued from the contract to the sender. This will transfer the entire balance of the matching ERC20 token.

Name	Type	Description
_address	address	The address of the token to be rescued

_addReceiver

function _addReceiver(uint256 _allocPoint, address _receiver, bool _isContract) internal virtual

Adds a FeeReceiver to our internally stored fee receivers array.

The new receiver will always be added to the end of the array.

Name	Type	Description
_allocPoint	uint256	The new allocation for the receiver
_receiver	address	The address of the receiver
_isContract	bool	Flag to determine if the receiver is a contract, rather than a wallet address

_sendForReceiver

function _sendForReceiver(struct INFTXSimpleFeeDistributor.FeeReceiver _receiver, uint256 _vaultId, address _vault, uint256 amountToSend) internal virtual returns (bool)

Sends the specified amount of tokens to a receiver from an NFTX vault.

If the receiver is a contract then they must implement receiveRewards to handle the fee distribution.

Name	Type	Description
_receiver	struct INFTXSimpleFeeDistributor.FeeReceiver	Address of the receiver contract or wallet
_vaultId	uint256	The ID of the NFTX vault, provided to the external contract
_vault	address	The address of the NFTX vault
amountToSend	uint256	The amount of tokens distributed to the receiver

Name	Type	Description
[0]	bool	bool If the tokens were successfully transferred and there are no more tokens left to transfer