Forta Staking

FortaStaking

_This is a generic staking contract for the Forta platform. It allows any account to deposit ERC20 tokens to delegate their "power" by staking on behalf of a particular subject. The subject can be scanner, or any other actor in the Forta ecosystem, who need to lock assets in order to contribute to the system.

Stakers take risks with their funds, as bad action from a subject can lead to slashing of the funds. In the meantime, stakers are elligible for rewards. Rewards distributed to a particular subject's stakers are distributed following to each staker's share in the subject.

Stakers can withdraw their funds, following a withdrawal delay. During the withdrawal delay, funds are no longer counting toward the active stake of a subject, but are still slashable.

The SLASHER_ROLE should be given to a smart contract that will be in charge of handling the slashing proposal process.

Stakers receive ERC1155 shares in exchange for their stake, making the active stake transferable. When a withdrawal is initiated, similarly the ERC1155 tokens representing the (transferable) active shares are burned in exchange for non-transferable ERC1155 tokens representing the inactive shares.

ERC1155 shares representing active stake are transferable, and can be used in an AMM. Their value is however subject to quick devaluation in case of slashing event for the corresponding subject. Thus, trading of such shares should be be done very carefully.

WARNING: To stake from another smart contract (smart contract wallets included), it must be fully ERC1155 compatible, implementing ERC1155Receiver. If not, minting of active and inactive shares will fail. Do not deposit on the constructor if you don't implement ERC1155Receiver. During the construction, the minting will succeed but you will not be able to withdraw or mint new shares from the contract. If this happens, transfer your shares to an EOA or fully ERC1155 compatible contract._

stakedToken

contract IERC20 stakedToken

_activeStake

struct Distributions.Balances _activeStake

_inactiveStake

struct Distributions.Balances _inactiveStake

_lockingDelay

mapping(uint256 => mapping(address => struct Timers.Timestamp)) _lockingDelay

_rewards

struct Distributions.Balances _rewards

_released

mapping(uint256 => struct Distributions.SignedBalances) _released

_deprecated_frozen

mapping(uint256 => bool) _deprecated_frozen

_withdrawalDelay

uint64 _withdrawalDelay

_treasury

address _treasury

subjectGateway

contract IStakeSubjectGateway subjectGateway

slashDelegatorsPercent

uint256 slashDelegatorsPercent

allocator

contract IStakeAllocator allocator

openProposals

mapping(uint256 => uint256) openProposals

_reentrancyStatus

uint256 _reentrancyStatus

MIN_WITHDRAWAL_DELAY

uint256 MIN_WITHDRAWAL_DELAY

MAX_WITHDRAWAL_DELAY

uint256 MAX_WITHDRAWAL_DELAY

MAX_SLASHABLE_PERCENT

uint256 MAX_SLASHABLE_PERCENT

HUNDRED_PERCENT

uint256 HUNDRED_PERCENT

StakeDeposited

event StakeDeposited(uint8 subjectType, uint256 subject, address account, uint256 amount)

WithdrawalInitiated

event WithdrawalInitiated(uint8 subjectType, uint256 subject, address account, uint64 deadline)

WithdrawalExecuted

event WithdrawalExecuted(uint8 subjectType, uint256 subject, address account)

Froze

event Froze(uint8 subjectType, uint256 subject, address by, bool isFrozen)

Slashed

event Slashed(uint8 subjectType, uint256 subject, address by, uint256 value)

SlashedShareSent

event SlashedShareSent(uint8 subjectType, uint256 subject, address by, uint256 value)

DelaySet

event DelaySet(uint256 newWithdrawalDelay)

TreasurySet

event TreasurySet(address newTreasury)

StakeHelpersConfigured

event StakeHelpersConfigured(address subjectGateway, address allocator)

MaxStakeReached

event MaxStakeReached(uint8 subjectType, uint256 subject)

TokensSwept

event TokensSwept(address token, address to, uint256 amount)

SlashDelegatorsPercentSet

event SlashDelegatorsPercentSet(uint256 percent)

WithdrawalNotReady

error WithdrawalNotReady()

SlashingOver90Percent

error SlashingOver90Percent()

WithdrawalSharesNotTransferible

error WithdrawalSharesNotTransferible()

FrozenSubject

error FrozenSubject()

NoActiveShares

error NoActiveShares()

NoInactiveShares

error NoInactiveShares()

StakeInactiveOrSubjectNotFound

error StakeInactiveOrSubjectNotFound()

version

string version

constructor

constructor(address _forwarder) public

initialize

function initialize(address __manager, contract IERC20 __stakedToken, uint64 __withdrawalDelay, address __treasury) public

Initializer method, access point to initialize inheritance tree.

Name	Type	Description
__manager	address	address of AccessManager.
__stakedToken	contract IERC20	ERC20 to be staked (FORT).
__withdrawalDelay	uint64	cooldown period between withdrawal init and withdrawal (in seconds).
__treasury	address	address where the slashed tokens go to.

setReentrancyGuard

function setReentrancyGuard() public

Reinitializer to setup the reentrancy guard (introduced in v0.1.2)

_setStatus

function _setStatus(uint256 newStatus) internal virtual

_getStatus

function _getStatus() internal virtual returns (uint256)

treasury

function treasury() public view returns (address)

Returns treasury address (slashed tokens destination)

activeStakeFor

function activeStakeFor(uint8 subjectType, uint256 subject) public view returns (uint256)

Get stake of a subject (not marked for withdrawal).

Name	Type	Description
subjectType	uint8	type id of Stake Subject. See SubjectTypeValidator.sol
subject	uint256	id identifying subject (external to FortaStaking).

Name	Type	Description
[0]	uint256	amount of stakedToken actively staked on subject+subjectType.

totalActiveStake

function totalActiveStake() public view returns (uint256)

Get total active stake of all subjects (not marked for withdrawal).

Name	Type	Description
[0]	uint256	amount of stakedToken actively staked on all subject+subjectTypes.

inactiveStakeFor

function inactiveStakeFor(uint8 subjectType, uint256 subject) external view returns (uint256)

Get inactive stake of a subject (marked for withdrawal).

Name	Type	Description
subjectType	uint8	type id of Stake Subject. See SubjectTypeValidator.sol
subject	uint256	id identifying subject (external to FortaStaking).

Name	Type	Description
[0]	uint256	amount of stakedToken still staked on subject+subjectType but marked for withdrawal.

totalInactiveStake

function totalInactiveStake() public view returns (uint256)

Get total inactive stake of all subjects (marked for withdrawal).

Name	Type	Description
[0]	uint256	amount of stakedToken still staked on all subject+subjectTypes but marked for withdrawal.

sharesOf

function sharesOf(uint8 subjectType, uint256 subject, address account) public view returns (uint256)

Get (active) shares of an account on a subject, corresponding to a fraction of the subject stake.

This is equivalent to getting the ERC1155 balanceOf for keccak256(abi.encodePacked(subjectType, subject)), shifted 9 bits, with the 9th bit set and uint8(subjectType) masked in

Name	Type	Description
subjectType	uint8	type id of Stake Subject. See SubjectTypeValidator.sol
subject	uint256	id identifying subject (external to FortaStaking).
account	address	holder of the ERC1155 staking shares.

Name	Type	Description
[0]	uint256	amount of ERC1155 shares account is in possession in representing stake on subject+subjectType.

totalShares

function totalShares(uint8 subjectType, uint256 subject) external view returns (uint256)

Get the total (active) shares on a subject.

This is equivalent to getting the ERC1155 totalSupply for keccak256(abi.encodePacked(subjectType, subject)), shifted 9 bits, with the 9th bit set and uint8(subjectType) masked in

Name	Type	Description
subjectType	uint8	type id of Stake Subject. See SubjectTypeValidator.sol
subject	uint256	id identifying subject (external to FortaStaking).

Name	Type	Description
[0]	uint256	total ERC1155 shares representing stake on subject+subjectType.

inactiveSharesOf

function inactiveSharesOf(uint8 subjectType, uint256 subject, address account) external view returns (uint256)

Get inactive shares of an account on a subject, corresponding to a fraction of the subject inactive stake.

This is equivalent to getting the ERC1155 balanceOf for keccak256(abi.encodePacked(subjectType, subject)), shifted 9 bits, with the 9th bit unset and uint8(subjectType) masked in.

Name	Type	Description
subjectType	uint8	type id of Stake Subject. See SubjectTypeValidator.sol
subject	uint256	id identifying subject (external to FortaStaking).
account	address	holder of the ERC1155 staking shares.

Name	Type	Description
[0]	uint256	amount of ERC1155 shares account is in possession in representing inactive stake on subject+subjectType, marked for withdrawal.

totalInactiveShares

function totalInactiveShares(uint8 subjectType, uint256 subject) external view returns (uint256)

Get the total inactive shares on a subject.

This is equivalent to getting the ERC1155 totalSupply for keccak256(abi.encodePacked(subjectType, subject)), shifted 9 bits, with the 9th bit unset and uint8(subjectType) masked in

Name	Type	Description
subjectType	uint8	type id of Stake Subject. See SubjectTypeValidator.sol
subject	uint256	id identifying subject (external to FortaStaking).

Name	Type	Description
[0]	uint256	total ERC1155 shares representing inactive stake on subject+subjectType, marked for withdrawal.

isFrozen

function isFrozen(uint8 subjectType, uint256 subject) public view returns (bool)

Checks if a subject frozen (stake of frozen subject cannot be withdrawn).

Name	Type	Description
subjectType	uint8	type id of Stake Subject. See SubjectTypeValidator.sol
subject	uint256	id identifying subject (external to FortaStaking).

Name	Type	Description
[0]	bool	true if subject is frozen, false otherwise

deposit

function deposit(uint8 subjectType, uint256 subject, uint256 stakeValue) external returns (uint256)

Deposit stakeValue tokens for a given subject, and mint the corresponding active ERC1155 shares. will return tokens staked over maximum for the subject. If stakeValue would drive the stake over the maximum, only stakeValue - excess is transferred, but transaction will not fail. Reverts if max stake for subjectType not set, or subject not found.

NOTE: Subject type is necessary because we can't infer subject ID uniqueness between scanners, agents, etc Emits a ERC1155.TransferSingle event and StakeDeposited (to allow accounting per subject type) Emits MaxStakeReached(subjectType, activeSharesId) WARNING: To stake from another smart contract (smart contract wallets included), it must be fully ERC1155 compatible, implementing ERC1155Receiver. If not, minting of active and inactive shares will fail. Do not deposit on the constructor if you don't implement ERC1155Receiver. During the construction, the minting will succeed but you will not be able to withdraw or mint new shares from the contract. If this happens, transfer your shares to an EOA or fully ERC1155 compatible contract.

Name	Type	Description
subjectType	uint8	type id of Stake Subject. See SubjectTypeValidator.sol
subject	uint256	id identifying subject (external to FortaStaking).
stakeValue	uint256	amount of staked token.

Name	Type	Description
[0]	uint256	amount of ERC1155 active shares minted.

migrate

function migrate(uint8 oldSubjectType, uint256 oldSubject, uint8 newSubjectType, uint256 newSubject, address staker) external

deposits active stake from SCANNER to SCANNER_POOL if not frozen. Inactive stake remains for withdrawal in old subject Burns active stake and shares for old subject.

No slash has been executed, so new SCANNER_POOL share proportions apply.

_getInboundStake

function _getInboundStake(uint8 subjectType, uint256 subject, uint256 stakeValue) private view returns (uint256, bool)

Calculates how much of the incoming stake fits for subject.

Name	Type	Description
subjectType	uint8	valid subect type
subject	uint256	the id of the subject
stakeValue	uint256	stake sent by staker

Name	Type	Description
[0]	uint256	stakeValue - excess
[1]	bool	true if reached max

initiateWithdrawal

function initiateWithdrawal(uint8 subjectType, uint256 subject, uint256 sharesValue) external returns (uint64)

Starts the withdrawal process for an amount of shares. Burns active shares and mints inactive shares (non transferrable). Stake will be available for withdraw() after _withdrawalDelay. If the subject has not been slashed, the shares will correspond 1:1 with stake.

Emits a WithdrawalInitiated event.

Name	Type	Description
subjectType	uint8	type id of Stake Subject. See SubjectTypeValidator.sol
subject	uint256	id identifying subject (external to FortaStaking).
sharesValue	uint256	amount of shares token.

Name	Type	Description
[0]	uint64	amount of time until withdrawal is valid.

withdraw

function withdraw(uint8 subjectType, uint256 subject) external returns (uint256)

Burn sharesValue inactive shares for a given subject, and withdraw the corresponding tokens (if the subject type has not been frozen, and the withdrawal delay time has passed).

shares must have been marked for withdrawal before by initiateWithdrawal(). Emits events WithdrawalExecuted and ERC1155.TransferSingle.

Name	Type	Description
subjectType	uint8	type id of Stake Subject. See SubjectTypeValidator.sol
subject	uint256	id identifying subject (external to FortaStaking).

Name	Type	Description
[0]	uint256	amount of withdrawn staked tokens.

slash

function slash(uint8 subjectType, uint256 subject, uint256 stakeValue, address proposer, uint256 proposerPercent) external returns (uint256)

Slash a fraction of a subject stake, and transfer it to the treasury. Restricted to the SLASHER_ROLE.

This will alter the relationship between shares and stake, reducing shares value for a subject. Emits a Slashed event. Unallocated stake if needed. A slash over a DELEGATED type will propagate to DELEGATORs according to proposerPercent.

Name	Type	Description
subjectType	uint8	type id of Stake Subject. See SubjectTypeValidator.sol
subject	uint256	id identifying subject (external to FortaStaking).
stakeValue	uint256	amount of staked token to be slashed.
proposer	address	address of the slash proposer. Must be nonzero address if proposerPercent > 0
proposerPercent	uint256	percentage of stakeValue sent to the proposer. From 0 to MAX_SLASHABLE_PERCENT

Name	Type	Description
[0]	uint256	stakeValue

_slash

function _slash(uint256 activeSharesId, uint8 subjectType, uint256 subject, uint256 stakeValue) private

burns slashed stake from active and/or inactive stake for subjectType/subject.

Name	Type	Description
activeSharesId	uint256	ERC1155 id of the shares being slashed
subjectType	uint8	type id of Stake Subject. See SubjectTypeValidator.sol
subject	uint256	id identifying subject (external to FortaStaking).
stakeValue	uint256	amount of staked token to be slashed.

freeze

function freeze(uint8 subjectType, uint256 subject, bool frozen) external

Freeze/unfreeze withdrawal of a subject stake. This will be used when something suspicious happens with a subject but there is not a strong case yet for slashing. Restricted to the SLASHER_ROLE.

Emits a Freeze event.

Name	Type	Description
subjectType	uint8	type id of Stake Subject. See SubjectTypeValidator.sol
subject	uint256	id identifying subject (external to FortaStaking).
frozen	bool	true to freeze, false to unfreeze.

_migrateFrozenToOpenProposals

function _migrateFrozenToOpenProposals(uint256 activeSharesId) private

If there is open cases before upgrading to openProposals (frozen == true), we increment as an extra proposal and set to false. There could be more than 1 open, in that case SLASHING_ARBITER_ROLE should be cautious with not unfreezing. This method will be obsolete when all the _deprecated_frozen are false

Name	Type	Description
activeSharesId	uint256	of the subject

sweep

function sweep(contract IERC20 token, address recipient) external returns (uint256)

Sweep all token that might be mistakenly sent to the contract. This covers both unrelated tokens and staked tokens that would be sent through a direct transfer. Restricted to SWEEPER_ROLE. If tokens are the same as staked tokens, only the extra tokens (no stake) will be transferred.

WARNING: thoroughly review the token to sweep.

Name	Type	Description
token	contract IERC20	address of the token to be swept.
recipient	address	destination address of the swept tokens

Name	Type	Description
[0]	uint256	amount of tokens swept. For unrelated tokens is FortaStaking's balance, for stakedToken its the balance over the active stake + inactive stake

relayPermit

function relayPermit(uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s) external

Relay a ERC2612 permit signature to the staked token. This cal be bundled with a {deposit} or a {reward} operation using Multicall.

Name	Type	Description
value	uint256	amount of token allowance for deposit/reward
deadline	uint256	for the meta-tx to be relayed.
v	uint8	part of signature
r	bytes32	part of signature
s	bytes32	part of signature

_beforeTokenTransfer

function _beforeTokenTransfer(address operator, address from, address to, uint256[] ids, uint256[] amounts, bytes data) internal virtual

See {ERC1155-_beforeTokenTransfer}.

stakeToActiveShares

function stakeToActiveShares(uint256 activeSharesId, uint256 amount) public view returns (uint256)

Convert active token stake amount to active shares amount

Name	Type	Description
activeSharesId	uint256	ERC1155 active shares id
amount	uint256	active stake amount

Name	Type	Description
[0]	uint256	ERC1155 active shares amount

stakeToInactiveShares

function stakeToInactiveShares(uint256 inactiveSharesId, uint256 amount) public view returns (uint256)

Convert inactive token stake amount to inactive shares amount

Name	Type	Description
inactiveSharesId	uint256	ERC1155 inactive shares id
amount	uint256	inactive stake amount

Name	Type	Description
[0]	uint256	ERC1155 inactive shares amount

activeSharesToStake

function activeSharesToStake(uint256 activeSharesId, uint256 amount) public view returns (uint256)

Convert active shares amount to active stake amount.

Name	Type	Description
activeSharesId	uint256	ERC1155 active shares id
amount	uint256	ERC1155 active shares amount

Name	Type	Description
[0]	uint256	active stake amount

inactiveSharesToStake

function inactiveSharesToStake(uint256 inactiveSharesId, uint256 amount) public view returns (uint256)

Convert inactive shares amount to inactive stake amount.

Name	Type	Description
inactiveSharesId	uint256	ERC1155 inactive shares id
amount	uint256	ERC1155 inactive shares amount

Name	Type	Description
[0]	uint256	inactive stake amount

setDelay

function setDelay(uint64 newDelay) external

Sets withdrawal delay. Restricted to DEFAULT_ADMIN_ROLE

Name	Type	Description
newDelay	uint64	in seconds.

setTreasury

function setTreasury(address newTreasury) external

Sets destination of slashed tokens. Restricted to DEFAULT_ADMIN_ROLE

Name	Type	Description
newTreasury	address	address.

configureStakeHelpers

function configureStakeHelpers(contract IStakeSubjectGateway _subjectGateway, contract IStakeAllocator _allocator) external

setSlashDelegatorsPercent

function setSlashDelegatorsPercent(uint256 percent) external

setURI

function setURI(string newUri) external

Sets URI of the ERC1155 tokens. Restricted to DEFAULT_ADMIN_ROLE

Name	Type	Description
newUri	string	root of the hosted metadata.

_msgSender

function _msgSender() internal view virtual returns (address sender)

Helper to get either msg msg.sender if not a meta transaction, signer of forwarder metatx if it is.

_msgData

function _msgData() internal view virtual returns (bytes)

Helper to get msg.data if not a meta transaction, forwarder data in metatx if it is.

__gap

uint256[36] __gap