Treasury

The treasury is a fee accumulator with a configurable rate. It implements OpenZeppelin Ownable for access control. For standard Ownable behavior (transfer_ownership, renounce_ownership), refer to the OZ documentation.

Constructor

__constructor(owner: Address, rate: i128)

Sets the OZ Ownable owner and the initial fee rate. The rate must be in [0, SCALAR_7/2] (0% to 50%).

Fee Rate

get_rate() -> i128 is permissionless. It returns the current fee rate in SCALAR_7 precision, defaulting to 0 if unset.

set_rate(rate: i128) is owner-only (#[only_owner]). The rate is bounded to [0, SCALAR_7/2] (0% to 50%). Setting a rate outside this range panics with TreasuryError::InvalidRate (900).

The trading contract calls get_rate() on every trade to compute the treasury's share. The protocol fee is defined as protocol_fee = base_fee + impact_fee + borrowing_fee (excludes funding, which is peer-to-peer). The treasury receives:

$$\text{treasury\_fee} = \lfloor \text{protocol\_fee} \times \frac{\text{rate}}{\text{SCALAR\_7}} \rfloor$$

Fee Collection

The treasury is a passive receiver. The trading contract pushes fees to the treasury address via standard token transfers. The treasury contract does not pull fees or track per-token accounting.

Withdrawal

withdraw(token: Address, to: Address, amount: i128) is owner-only. It can withdraw any SEP-41 token held by the treasury. There is no per-token accounting or whitelist.

Storage

The treasury uses only instance storage (30-day TTL):

Key	Type	Description
"Rate"	i128	Protocol fee rate (SCALAR_7)
OZ Ownable	Address	Owner address (managed internally)

Immutability in Trading

The treasury address is set in the trading contract's constructor and stored in instance storage with no setter. Once deployed, the trading contract always sends protocol fees to the same treasury. Changing the treasury requires redeploying the trading contract.