L2 veCRV Delegation

The L2veCRVDelegation contract enables users to delegate their veCRV voting power to different addresses on other networks (Layer 2s or sidechains). This is essential for veCRV-utility activities like veCRV boosting on chains where their original address may not be available or convenient. The contract supports both user-initiated delegation and DAO-administered delegation for special cases (e.g., lost keys or non-reachable addresses). The contract also includes mechanisms to allow or revoke delegation to an address and to prevent frontrunning attacks.

L2veCRVDelegation.vy

The source code for the L2veCRVDelegation.vy contract is available on GitHub. The contract is written in Vyper version 0.4.0.

The VotingEscrow on Ethereum is deployed at 0xde1e6A7E8297076f070E857130E593107A0E0cF5 and contract version is 0.0.1.

Contract ABI

[{"anonymous":false,"inputs":[{"indexed":true,"name":"_chain_id","type":"uint256"},{"indexed":true,"name":"_to","type":"address"}],"name":"AllowDelegation","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"_chain_id","type":"uint256"},{"indexed":true,"name":"_from","type":"address"},{"indexed":false,"name":"_to","type":"address"}],"name":"Delegate","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"previous_owner","type":"address"},{"indexed":true,"name":"new_owner","type":"address"}],"name":"OwnershipTransferred","type":"event"},{"inputs":[{"name":"new_owner","type":"address"}],"name":"transfer_ownership","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"owner","outputs":[{"name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[{"name":"_chain_id","type":"uint256"},{"name":"_from","type":"address"}],"name":"delegated","outputs":[{"name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[{"name":"_chain_id","type":"uint256"},{"name":"_to","type":"address"}],"name":"delegator","outputs":[{"name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[{"name":"_chain_id","type":"uint256"},{"name":"_to","type":"address"}],"name":"delegation_allowed","outputs":[{"name":"","type":"bool"}],"stateMutability":"view","type":"function"},{"inputs":[{"name":"_chain_id","type":"uint256"},{"name":"_to","type":"address"}],"name":"delegate","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"name":"_chain_id","type":"uint256"}],"name":"allow_delegation","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"name":"_chain_id","type":"uint256"},{"name":"_allow","type":"bool"}],"name":"allow_delegation","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"name":"_chain_id","type":"uint256"},{"name":"_from","type":"address"},{"name":"_to","type":"address"}],"name":"delegate_from","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"version","outputs":[{"name":"","type":"string"}],"stateMutability":"view","type":"function"},{"inputs":[{"name":"_owner","type":"address"}],"outputs":[],"stateMutability":"nonpayable","type":"constructor"}]

Delegation¶

The delegation system in L2veCRVDelegation is designed to be flexible and secure. Users can delegate their veCRV voting power to another address on a specific chain, revoke delegation, or allow others to delegate to them. The contract also provides DAO-level controls for exceptional cases, ensuring that delegation can be managed even if a user is unable to interact directly. The following functions describe the available delegation mechanisms and their intended use cases.

`delegate`¶

L2veCRVDelegation.delegate(_chain_id: uint256, _to: address)

Function to delegate veCRV to another address on a specific chain. Only addresses that have explicitly allowed delegation (via allow_delegation) can be delegated to. To revoke delegation, delegate to your own address.

Emits: Delegate event.

Input	Type	Description
`_chain_id`	`uint256`	Chain ID where to set the delegation
`_to`	`address`	Address to delegate to

Source code

L2veCRVDelegation.vy

event Delegate:
    _chain_id: indexed(uint256)
    _from: indexed(address)
    _to: address

# [chain id][address from][address to]
delegation_from: HashMap[uint256, HashMap[address, address]]
delegation_to: HashMap[uint256, HashMap[address, address]]

@external
def delegate(_chain_id: uint256, _to: address):
    """
    @notice Delegate veCRV balance to another address
    @dev To revoke delegation set delegation to yourself
    @param _chain_id Chain ID where to set
    @param _to Address to delegate to
    """
    assert self.delegation_to[_chain_id][_to] == self, "Not allowed"
    self._delegate(_chain_id, msg.sender, _to)

def _delegate(_chain_id: uint256, _from: address, _to: address):
    # Clean previous delegation
    prev_to: address = self.delegation_from[_chain_id][_from]
    if prev_to not in [empty(address), self]:
        self.delegation_to[_chain_id][prev_to] = empty(address)

    self.delegation_from[_chain_id][_from] = _to
    self.delegation_to[_chain_id][_to] = _from
    log Delegate(_chain_id, _from, _to)

Example

This example delegates their veCRV balance to 0x71F718D3e4d1449D1502A6A7595eb84eBcCB1683 on chain 146

>>> L2veCRVDelegation.delegate(146, '0x71F718D3e4d1449D1502A6A7595eb84eBcCB1683')

`delegate_from`¶

L2veCRVDelegation.delegate_from(_chain_id: uint256, _from: address, _to: address)

DAO-only function to set delegation for addresses that cannot interact directly (e.g., lost keys or non-reachable addresses). Only callable by the contract owner.

Emits: Delegate event.

Input	Type	Description
`_chain_id`	`uint256`	Chain ID where to set the delegation
`_from`	`address`	Address that delegates
`_to`	`address`	Address balance being delegated to

Source code

L2veCRVDelegation.vy

from snekmate.auth import ownable

event Delegate:
    _chain_id: indexed(uint256)
    _from: indexed(address)
    _to: address

# [chain id][address from][address to]
delegation_from: HashMap[uint256, HashMap[address, address]]
delegation_to: HashMap[uint256, HashMap[address, address]]

@external
def delegate_from(_chain_id: uint256, _from: address, _to: address):
    """
    @notice DAO-owned method to set delegation for non-reachable addresses
    @param _chain_id Chain ID where to set
    @param _from Address that delegates
    @param _to Address balance being delegated to
    """
    ownable._check_owner()

    self._delegate(_chain_id, _from, _to)

def _delegate(_chain_id: uint256, _from: address, _to: address):
    # Clean previous delegation
    prev_to: address = self.delegation_from[_chain_id][_from]
    if prev_to not in [empty(address), self]:
        self.delegation_to[_chain_id][prev_to] = empty(address)

    self.delegation_from[_chain_id][_from] = _to
    self.delegation_to[_chain_id][_to] = _from
    log Delegate(_chain_id, _from, _to)

Example

In this example, the DAO delegates the veCRV balance from 0x5802ad5D5B1c63b3FC7DE97B55e6db19e5d36462 to 0x71F718D3e4d1449D1502A6A7595eb84eBcCB1683 on chain 146.

# DAO sets delegation for a non-reachable address
>>> L2veCRVDelegation.delegate_from(146, '0x5802ad5D5B1c63b3FC7DE97B55e6db19e5d36462', '0x71F718D3e4d1449D1502A6A7595eb84eBcCB1683')

`allow_delegation`¶

L2veCRVDelegation.allow_delegation(_chain_id: uint256, _allow: bool = True)

Allows or revokes permission for others to delegate veCRV to your address on a specific chain. This must be called before anyone can delegate to you, and is required to prevent frontrunning attacks.

Emits: AllowDelegation or Delegate event.

Input	Type	Description
`_chain_id`	`uint256`	Chain ID
`_allow`	`bool`	`true` to allow delegation, `false` to remove; defaults to `true`

Source code

L2veCRVDelegation.vy

event AllowDelegation:
    _chain_id: indexed(uint256)
    _to: indexed(address)

event Delegate:
    _chain_id: indexed(uint256)
    _from: indexed(address)
    _to: address

# [chain id][address from][address to]
delegation_from: HashMap[uint256, HashMap[address, address]]
delegation_to: HashMap[uint256, HashMap[address, address]]

@external
def allow_delegation(_chain_id: uint256, _allow: bool = True):
    """
    @notice Allow delegation to your address
    @dev Needed to deal with frontrun
    @param _chain_id Chaind ID to allow for
    @param _allow True(default) if allow, and False to remove delegation
    """
    # Clean current delegation
    _from: address = self.delegation_to[_chain_id][msg.sender]
    if _from not in [empty(address), self]:
        self.delegation_from[_chain_id][_from] = empty(address)
        log Delegate(_chain_id, _from, empty(address))

    if _allow:
        self.delegation_to[_chain_id][msg.sender] = self
        log AllowDelegation(_chain_id, msg.sender)
    else:
        self.delegation_to[_chain_id][msg.sender] = empty(address)

Example

This example shows how to allow and revoke delegation.

>>> L2veCRVDelegation.allow_delegation(146, True)       # Allow delegation to your address on chain 146

>>> L2veCRVDelegation.allow_delegation(146, False)      # Revoke delegation

`delegation_allowed`¶

L2veCRVDelegation.delegation_allowed(_chain_id: uint256, _to: address) -> bool

Getter method to check whether delegation to a given address is currently allowed on a specific chain.

Returns: true if delegation is allowed, false otherwise.

Input	Type	Description
`_chain_id`	`uint256`	Chain ID
`_to`	`address`	Address to check for

Source code

L2veCRVDelegation.vy

delegation_to: HashMap[uint256, HashMap[address, address]]

@external
@view
def delegation_allowed(_chain_id: uint256, _to: address) -> bool:
    """
    @notice Check whether delegation to this address is allowed
    @param _chain_id Chain ID to check for
    @param _to Address to check for
    @return True if allowed to delegate
    """
    return self.delegation_to[_chain_id][_to] == self

Example

This example checks if delegation for 0x71F718D3e4d1449D1502A6A7595eb84eBcCB1683 is allowed on chain 146.

>>> L2veCRVDelegation.delegation_allowed(146, '0x71F718D3e4d1449D1502A6A7595eb84eBcCB1683')
True

`delegated`¶

L2veCRVDelegation.delegated(_chain_id: uint256, _from: address) -> address

Returns the address to which a given user's veCRV balance is delegated on a specific chain. If no delegation is set, returns the original address.

Input	Type	Description
`_chain_id`	`uint256`	Chain ID
`_from`	`address`	Delegator

Source code

L2veCRVDelegation.vy

delegation_from: HashMap[uint256, HashMap[address, address]]

@external
@view
def delegated(_chain_id: uint256, _from: address) -> address:
    """
    @notice Get contract balance being delegated to
    @param _chain_id Chain ID to check for
    @param _from Address of delegator
    @return Destination address of delegation
    """
    addr: address = self.delegation_from[_chain_id][_from]
    if addr == empty(address):
        addr = _from
    return addr

Example

In this example, address 0x5802ad5D5B1c63b3FC7DE97B55e6db19e5d36462 delegated his veCRV balance on chain 146 to 0x71F718D3e4d1449D1502A6A7595eb84eBcCB1683.

>>> L2veCRVDelegation.delegated(146, '0x5802ad5D5B1c63b3FC7DE97B55e6db19e5d36462')
'0x71F718D3e4d1449D1502A6A7595eb84eBcCB1683'

`delegator`¶

L2veCRVDelegation.delegator(_chain_id: uint256, _to: address) -> address

Getter for the address that delegated their veCRV balance to a given address on a specific chain. If no delegator is set, returns the _to address itself.

Returns: delegator (address).

Input	Type	Description
`_chain_id`	`uint256`	Chain ID where to set the delegation
`_to`	`address`	Delegatee

Source code

L2veCRVDelegation.vy

delegation_to: HashMap[uint256, HashMap[address, address]]

@external
@view
def delegator(_chain_id: uint256, _to: address) -> address:
    """
    @notice Get contract delegating balance to `_to`
    @param _chain_id Chain ID to check for
    @param _to Address of delegated to
    @return Address of delegator
    """
    addr: address = self.delegation_to[_chain_id][_to]
    if addr in [empty(address), self]:
        return _to
    return addr

Example

This example returns the address which delegated their veCRV balance on chain 146 to 0x71F718D3e4d1449D1502A6A7595eb84eBcCB1683, essentially the delegator.

>>> L2veCRVDelegation.delegator(146, '0x71F718D3e4d1449D1502A6A7595eb84eBcCB1683')
'0x5802ad5D5B1c63b3FC7DE97B55e6db19e5d36462'

Contract Ownership¶

Contract ownership is handled via the snekmate ownable module. The owner of the contract is the DAO, and ownership can be transferred using the transfer_ownership() function.

L2 veCRV Delegation

Delegation¶

delegate¶

delegate_from¶

allow_delegation¶

delegation_allowed¶

delegated¶

delegator¶

Contract Ownership¶

`delegate`¶

`delegate_from`¶

`allow_delegation`¶

`delegation_allowed`¶

`delegated`¶

`delegator`¶