AaveLendingModule.sol

Lending functions are standardized for STEX AMM using a Lending Module, upgradable under timelock in the Withdrawal Module. This allows new lending markets with custom integration logic to be added without redeploying STEX AMM.

The AAVE Lending Module Facilitate deposits and withdrawals with Aave v3 protocol for yield generation on supported assets. Owner of this contract is set as the Withdrawal Module.

Core Market Interactions

1. deposit()

Purpose: Deposit Native Token (token1) into Aave v3 pool

// deposit _amount of token1 reserves into the aave lending pool
function deposit(uint256 _amount) external onlyOwner

Checks:

• Can only be called by owner, which is set as the Withdrawal Module

• Reentrancy safety handled by Aave

Flow:

• Transfer asset from sender (Withdrawal Module) to Lending Module contract

• Approve Aave pool to spend assets

• Call Aave's supply() to mint aToken

• aTokens are held in the AaveLendingModule

2. Withdraw()

Purpose: Redeem assets from Aave v3Parameters

// withdraw _amount of token1 reserves into the aave lending pool and send to _recipient
function withdraw(uint256 _amount, address _recipient) external onlyOwner

Parameters:

• _amount: aTokens to redeem

• _recipient: Asset receiver address

  • In the case where withdraw is initiated by owner, recipient is the pool

  • In the case where withdraw is initiated by STEXAMM for an LP withdraw: recipient can be the user directly, or DepositWrapper when unwrapping is needed

  • In the case where withdraw is initiated as a result of a change to the Lending Module, recipient is the Withdrawal Module

Checks:

• Only callable by Owner (Withdraw Module)

• Recipient cannot be zero address (enforced by Aave)

• Sufficient aToken balance

Flow:

• Calls Aave's withdraw()

• Transfers underlying asset directly to recipient

• Burns corresponding aTokens

Helper Functions

1. assetBalance()

Purpose: Check current aToken holdings

// returns the lending modules balance of aTokens
function assetBalance() external view returns (uint256)

Returns:

• aToken balance of contract

  • Represents total deposited token1 + yield earned

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