BuyBack Contract Overview

Buyback.sol is a smart contract designed to automate the repurchase of FACTR tokens from the open market using USDC. These repurchased tokens are locked and later distributed to designated vaults or custom addresses.

Contract Versions

This contract has an audited version, with future iterations potentially expanding its flexibility, efficiency, and support for multi-chain integrations.

Buyback Smart Contract Documentation

Overview

The Buyback contract enables automated and custom buybacks of FACTR tokens using USDC, leveraging Uniswap V3 swaps and a cooldown mechanism to ensure stability and prevent market manipulation. After a 1-year lock-up period, the repurchased FACTR is distributed to vaults or user-defined addresses.

Dependencies

• IERC20: Interface for interacting with ERC20 tokens.
• ISwapRouter: Uniswap V3 router interface for token swaps.
• OracleLibrary: Uniswap V3 price oracle for TWAP (time-weighted average price).
• IUniswapV3Factory, IUniswapV3Pool: Uniswap V3 pool discovery and interaction.

Constants

• ONE_THOUSAND: Minimum USDC required for a buyback (1,000 USDC).
• TEN_THOUSAND: Basis points constant (10,000).
• BUY_FREQUENCY: Cooldown duration between buybacks.
• POOL_1_FEE, POOL_2_FEE: Fee tiers for USDC-WETH and WETH-FACTR pools.
• THREE_HUNDRED: Swap deadline time buffer (in seconds).

Roles

This contract doesn’t implement a granular role-based system but does include privileged functions callable only by the designated RECOVERER address.

Buyback

Two buyback mechanisms exist:

Normal Buyback

Executes a FACTR buyback using available USDC. Ensures optimal pricing via TWAP checks, and records swap details in a structured array (buybacks).

• coolDownElapsed modifier: Prevents execution if a cooldown period has not passed.
• _sandwichProtectionCheck: Checks if current prices deviate by more than 1% from TWAP.
• calculateOptimalAmount: Calculates max amount to swap that meets price criteria.

Custom Buyback

Allows any user to initiate a buyback by transferring at least 1,000 USDC and specifying a distribution of the resulting FACTR.

• Distribution must sum to 10000 bps.
• Tokens are locked for 1 year before being claimable.

Withdrawals

FACTR tokens are distributed after a 1-year lock via the buybackWithdraw or customBuybackWithdraw functions.

Vaults (Normal Buybacks)

FACTR is distributed equally among four vault addresses.

Custom Addresses (Custom Buybacks)

FACTR is split according to the predefined bps (basis points) distribution array.

Functions

Core Functions

• buyback: Executes a standard buyback using contract-held USDC.
• customBuyback: Executes a user-funded buyback and stores custom distribution logic.
• buybackWithdraw: Unlocks FACTR from a normal buyback after 1 year.
• customBuybackWithdraw: Unlocks FACTR from a custom buyback after 1 year.
• fetchActiveLocks: Returns an array of normal buybacks pending withdrawal.
• fetchActiveCustomLocks: Returns an array of custom buybacks pending withdrawal.

Internal Logic

• _sandwichProtectionCheck: Reverts if price deviation exceeds 1%.
• _executeSwap: Handles Uniswap V3 swap execution with slippage protections.
• calculateOptimalAmount: Determines optimal swap amount using TWAP.
• getOptimalTwapAmountThreshold: Calculates TWAP-based minimum output for a given input.

Admin Utility

• recoverERC20: Allows recovery of tokens (excluding FACTR and USDC) stuck in the contract.

Events

• BuybackCall: Emitted after a normal buyback.
• CustomBuybackCall: Emitted after a custom buyback.
• Withdraw: Emitted when FACTR is distributed from a normal buyback.
• CustomWithdraw: Emitted when FACTR is distributed from a custom buyback.
• ERC20Recovered: Emitted on recovery of any ERC20 tokens.

Security Considerations

• Audit: Contract was audited by Zokyo Security and passed with a 95/100 score. No critical issues were found. Minor findings were acknowledged or resolved.
• TWAP checks: Ensures price stability against MEV or price manipulation attacks.
• 1-Year Lock: Prevents immediate token release post-buyback, enhancing tokenomics design.
• Fallback Protection: Ensures that even if users delay custom withdraws, tokens remain locked safely.

Note: All buyback data is stored on-chain and accessible via public getters or events. Future UI integrations (e.g., Engage dashboard) are expected to display this information transparently.