Plain and Meta-Pool Implementation with Custom Admin Controls

This implementation enables **arbitrary assignment of an admin and admin_fee**for a specific pool. The Factory.admin() is, and will always remain, one of the pool’s owners—ensuring full control via the DAO.

Contract Implementations

The source code for the implementation can be found on GitHub in the admin-implementation branch. This implementation is initially used by CrossCurve on Sonic.

The implementations were added to the StableSwapFactory on Sonic via Vote ID #1010 and are deployed at index = 710420.

>>> Factory.metapool_implementations(710420)
'0x8663426e8713922D81e44d73295759e74Afc230F'

>>> Factory.pool_implementations(710420)
'0xA7c2DD4356168153792EF05D27922064b3c71A26'

The implementation introduces the ability to designate an additional admin with the following permissions:

• The admin has the authority to set the contract’s admin fee, which can range from 0% to 100%. Previously, this fee was hardcoded at 50%.
• Once an admin is set, their address replaces the fee_receiver and starts receiving all pool admin fees. If no admin is set, the fee_receiver remains the default recipient.

At contract initialization, the admin is set to ZERO_ADDRESS. This means assigning a new admin requires a DAO vote via the set_admin function. The admin_fee defaults to 50% but can be updated later.

---

admin

CurveStableSwap.admin() -> address: view

Getter for the admin of the contract. At contract initialization, the address of the admin is always set to ZERO_ADDRESS.

Returns: admin of the contract (address).

<>Source code▼

@external
def __init__(
    ...
):

    ...
    self.admin = empty(address)
    ...

admin: public(address)

▶Example▼

This example returns the current admin of the contract.

>>> CurveStableSwap.admin()
'0x0000000000000000000000000000000000000000'

set_admin

CurveStableSwap.set_admin(_new_admin: address)

Guarded Method

This function is only callable by the admin of the Factory.

Function to set the admin of the contract. Setting the admin will revert if its not called by the admin of the Factory.

Emits: SetAdmin event.

Input	Type	Description
_new_admin	address	New admin address.

<>Source code▼

interface Factory:
    def fee_receiver() -> address: view

event SetAdmin:
    admin: address

admin: public(address)

@external
def set_admin(_new_admin: address):
    assert msg.sender == factory.admin()  # dev: only owner

    self.admin = _new_admin
    log SetAdmin(_new_admin)

@view
@internal
def _check_admins():
    assert msg.sender == factory.admin() or msg.sender == self.admin  # dev: only admin

▶Example▼

This example sets the admin of the contract.

>>> CurveStableSwap.admin()
'0x0000000000000000000000000000000000000000'

>>> CurveStableSwap.set_admin('0x7a16ff8270133f063aab6c9977183d9e72835428')

>>> CurveStableSwap.admin()
'0x7a16ff8270133f063aab6c9977183d9e72835428'

---

admin_fee

CurveStableSwap.admin_fee() -> uint256: view

Getter for the admin fee of the pool. At contract initialization, the admin fee is set to 50%.

Returns: admin fee (uint256).

<>Source code▼

@external
def __init__(
    ...
):

    ...
    self.admin_fee = 5000000000
    ...

admin_fee: public(uint256)

▶Example▼

This example returns the current admin fee of the contract.

>>> CurveStableSwap.admin()
'0x0000000000000000000000000000000000000000'

set_new_admin_fee

CurveStableSwap.set_new_admin_fee(_new_admin_fee: uint256):

Guarded Method

This function is only callable by the admin of the Pool or the Factory.

Function to set the admin fee of the pool.

Emits: SetAdmin event.

Input	Type	Description
_new_admin_fee	uint256	New admin fee value.

<>Source code▼

interface Factory:
    def fee_receiver() -> address: view

event ApplyNewAdminFee:
    admin_fee: uint256

admin_fee: public(uint256)

FEE_DENOMINATOR: constant(uint256) = 10 **10

@external
def set_new_admin_fee(_new_admin_fee: uint256):
    self._check_admins()
    # FEE_DENOMINATOR = 1 = 100%
    assert _new_admin_fee <= FEE_DENOMINATOR  # dev: more than 100%

    self.admin_fee = _new_admin_fee
    log ApplyNewAdminFee(_new_admin_fee)

@view
@internal
def _check_admins():
    assert msg.sender == factory.admin() or msg.sender == self.admin  # dev: only admin

▶Example▼

This example sets the admin of the contract.

>>> StableSwapNG.admin_fee()
5000000000

>>> StableSwapNG.set_new_admin_fee(0)

>>> StableSwapNG.admin_fee()
0