# Pool Implementation

#### 🔹 Constructor

* **constructor(IPoolAddressesProvider provider)**\
  Initializes the pool with the address provider that manages system-wide addresses.

***

#### 🔹 Core State-Changing Functions

* **supply(asset, amount, onBehalfOf, referralCode)**\
  Deposit an asset into the protocol to earn yield. `onBehalfOf` allows crediting another user.
* **supplyWithPermit(asset, amount, onBehalfOf, referralCode, deadline, v, r, s)**\
  Same as `supply`, but uses EIP-2612 permit signatures to approve in a gas-efficient way.
* **withdraw(asset, amount, to)** → `uint256`\
  Withdraw supplied assets from the protocol and send them to `to`.
* **borrow(asset, amount, interestRateMode, referralCode, onBehalfOf)**\
  Borrow funds from the pool, choosing **stable** or **variable** interest rate.
* **repay(asset, amount, interestRateMode, onBehalfOf)** → `uint256`\
  Repay borrowed funds.
* **repayWithATokens(asset, amount, interestRateMode)** → `uint256`\
  Repay debt using `aTokens` instead of underlying asset.
* **repayWithPermit(asset, amount, interestRateMode, onBehalfOf, deadline, v, r, s)** → `uint256`\
  Repay using ERC-20 permit authorization.
* **swapBorrowRateMode(asset, interestRateMode)**\
  Switch between **stable** and **variable** borrowing modes.
* **rebalanceStableBorrowRate(asset, user)**\
  Adjust a user’s stable borrow rate to the current optimal one.
* **setUserUseReserveAsCollateral(asset, useAsCollateral)**\
  Enable or disable an asset as collateral.
* **liquidationCall(collateralAsset, debtAsset, user, debtToCover, receiveAToken)**\
  Liquidate a user’s debt if their health factor is too low. Liquidator repays debt and receives collateral.

***

#### 🔹 Flash Loans

* **flashLoan(receiver, assets\[], amounts\[], interestRateModes\[], onBehalfOf, params, referralCode)**\
  Multi-asset flash loan.
* **flashLoanSimple(receiver, asset, amount, params, referralCode)**\
  Simpler single-asset flash loan.

***

#### 🔹 Treasury / Protocol Functions

* **mintUnbacked(asset, amount, onBehalfOf, referralCode)**\
  Mint `aTokens` without providing liquidity (used in bridges).
* **backUnbacked(asset, amount, fee)** → `uint256`\
  Provide the underlying liquidity to back unbacked `aTokens`.
* **mintToTreasury(assets\[])**\
  Mint reserves accrued to the protocol treasury.
* **rescueTokens(token, to, amount)**\
  Recover ERC-20 tokens mistakenly sent to the pool.

***

#### 🔹 Configuration / Admin Functions

* **initReserve(asset, aToken, stableDebtToken, variableDebtToken, interestRateStrategy)**\
  Initialize a new reserve (asset market).
* **dropReserve(asset)**\
  Remove a reserve from the pool.
* **setConfiguration(asset, config)**\
  Update reserve risk parameters.
* **setReserveInterestRateStrategyAddress(asset, strategy)**\
  Change the interest rate strategy for a reserve.
* **configureEModeCategory(id, category)**\
  Create/update an eMode category (optimized LTVs for correlated assets).
* **setUserEMode(categoryId)**\
  Set a user’s efficiency mode.
* **updateBridgeProtocolFee(protocolFee)**\
  Adjust fee for bridge usage.
* **updateFlashloanPremiums(totalPremium, premiumToProtocol)**\
  Adjust flash loan fee parameters.
* **resetIsolationModeTotalDebt(asset)**\
  Reset debt tracking for isolation-mode assets.
* **finalizeTransfer(asset, from, to, amount, balanceFromBefore, balanceToBefore)**\
  Internal bookkeeping when `aTokens` are transferred.

***

#### 🔹 View / Read Functions

* **ADDRESSES\_PROVIDER() → address**\
  Returns the address provider.
* **BRIDGE\_PROTOCOL\_FEE() → uint256**\
  Fee applied to bridge mints.
* **FLASHLOAN\_PREMIUM\_TOTAL() → uint128**\
  Total flash loan fee (bps).
* **FLASHLOAN\_PREMIUM\_TO\_PROTOCOL() → uint128**\
  Portion of fee directed to protocol treasury.
* **MAX\_NUMBER\_RESERVES() → uint16**\
  Maximum number of reserves allowed.
* **MAX\_STABLE\_RATE\_BORROW\_SIZE\_PERCENT() → uint256**\
  Limit on stable-rate borrowing as % of liquidity.
* **POOL\_REVISION() → uint256**\
  Contract revision number.
* **getConfiguration(asset)**\
  Returns the encoded reserve configuration.
* **getReserveData(asset)**\
  Returns detailed reserve state (indexes, rates, addresses, treasury accruals, etc.).
* **getReserveNormalizedIncome(asset) → uint256**\
  Normalized liquidity index.
* **getReserveNormalizedVariableDebt(asset) → uint256**\
  Normalized variable debt index.
* **getReservesList() → address\[]**\
  Returns the list of all active reserves.
* **getReserveAddressById(id) → address**\
  Get reserve address by internal ID.
* **getEModeCategoryData(id)**\
  Returns parameters of an eMode category (LTV, liquidation thresholds, etc.).
* **getUserAccountData(user)**\
  Returns total collateral, total debt, available borrows, liquidation threshold, LTV, and health factor.
* **getUserConfiguration(user)**\
  Returns bitmaps of user’s asset usage (collateral/borrow).
* **getUserEMode(user) → uint256**\
  Returns the efficiency mode category a user is in.

***

#### 🔹 Events

* **Supply, Withdraw, Borrow, Repay, LiquidationCall, FlashLoan, MintUnbacked, BackUnbacked, ReserveDataUpdated, ReserveUsedAsCollateralEnabled/Disabled, UserEModeSet**\
  All these track on-chain state changes for transparency and analytics.

```
[
  {
    "type": "constructor",
    "inputs": [
      { "name": "provider", "internalType": "contract IPoolAddressesProvider", "type": "address" }
    ],
    "stateMutability": "nonpayable"
  },
  {
    "type": "event",
    "name": "BackUnbacked",
    "inputs": [
      { "indexed": true, "name": "reserve", "internalType": "address", "type": "address" },
      { "indexed": true, "name": "backer", "internalType": "address", "type": "address" },
      { "indexed": false, "name": "amount", "internalType": "uint256", "type": "uint256" },
      { "indexed": false, "name": "fee", "internalType": "uint256", "type": "uint256" }
    ],
    "anonymous": false
  },
  {
    "type": "event",
    "name": "Borrow",
    "inputs": [
      { "indexed": true, "name": "reserve", "internalType": "address", "type": "address" },
      { "indexed": false, "name": "user", "internalType": "address", "type": "address" },
      { "indexed": true, "name": "onBehalfOf", "internalType": "address", "type": "address" },
      { "indexed": false, "name": "amount", "internalType": "uint256", "type": "uint256" },
      { "indexed": false, "name": "interestRateMode", "internalType": "enum DataTypes.InterestRateMode", "type": "uint8" },
      { "indexed": false, "name": "borrowRate", "internalType": "uint256", "type": "uint256" },
      { "indexed": true, "name": "referralCode", "internalType": "uint16", "type": "uint16" }
    ],
    "anonymous": false
  },
  {
    "type": "event",
    "name": "FlashLoan",
    "inputs": [
      { "indexed": true, "name": "target", "internalType": "address", "type": "address" },
      { "indexed": false, "name": "initiator", "internalType": "address", "type": "address" },
      { "indexed": true, "name": "asset", "internalType": "address", "type": "address" },
      { "indexed": false, "name": "amount", "internalType": "uint256", "type": "uint256" },
      { "indexed": false, "name": "interestRateMode", "internalType": "enum DataTypes.InterestRateMode", "type": "uint8" },
      { "indexed": false, "name": "premium", "internalType": "uint256", "type": "uint256" },
      { "indexed": true, "name": "referralCode", "internalType": "uint16", "type": "uint16" }
    ],
    "anonymous": false
  },
  {
    "type": "event",
    "name": "IsolationModeTotalDebtUpdated",
    "inputs": [
      { "indexed": true, "name": "asset", "internalType": "address", "type": "address" },
      { "indexed": false, "name": "totalDebt", "internalType": "uint256", "type": "uint256" }
    ],
    "anonymous": false
  },
  {
    "type": "event",
    "name": "LiquidationCall",
    "inputs": [
      { "indexed": true, "name": "collateralAsset", "internalType": "address", "type": "address" },
      { "indexed": true, "name": "debtAsset", "internalType": "address", "type": "address" },
      { "indexed": true, "name": "user", "internalType": "address", "type": "address" },
      { "indexed": false, "name": "debtToCover", "internalType": "uint256", "type": "uint256" },
      { "indexed": false, "name": "liquidatedCollateralAmount", "internalType": "uint256", "type": "uint256" },
      { "indexed": false, "name": "liquidator", "internalType": "address", "type": "address" },
      { "indexed": false, "name": "receiveAToken", "internalType": "bool", "type": "bool" }
    ],
    "anonymous": false
  },
  {
    "type": "event",
    "name": "MintUnbacked",
    "inputs": [
      { "indexed": true, "name": "reserve", "internalType": "address", "type": "address" },
      { "indexed": false, "name": "user", "internalType": "address", "type": "address" },
      { "indexed": true, "name": "onBehalfOf", "internalType": "address", "type": "address" },
      { "indexed": false, "name": "amount", "internalType": "uint256", "type": "uint256" },
      { "indexed": true, "name": "referralCode", "internalType": "uint16", "type": "uint16" }
    ],
    "anonymous": false
  },
  {
    "type": "event",
    "name": "MintedToTreasury",
    "inputs": [
      { "indexed": true, "name": "reserve", "internalType": "address", "type": "address" },
      { "indexed": false, "name": "amountMinted", "internalType": "uint256", "type": "uint256" }
    ],
    "anonymous": false
  },
  {
    "type": "event",
    "name": "RebalanceStableBorrowRate",
    "inputs": [
      { "indexed": true, "name": "reserve", "internalType": "address", "type": "address" },
      { "indexed": true, "name": "user", "internalType": "address", "type": "address" }
    ],
    "anonymous": false
  },
  {
    "type": "event",
    "name": "Repay",
    "inputs": [
      { "indexed": true, "name": "reserve", "internalType": "address", "type": "address" },
      { "indexed": true, "name": "user", "internalType": "address", "type": "address" },
      { "indexed": true, "name": "repayer", "internalType": "address", "type": "address" },
      { "indexed": false, "name": "amount", "internalType": "uint256", "type": "uint256" },
      { "indexed": false, "name": "useATokens", "internalType": "bool", "type": "bool" }
    ],
    "anonymous": false
  },
  {
    "type": "event",
    "name": "ReserveDataUpdated",
    "inputs": [
      { "indexed": true, "name": "reserve", "internalType": "address", "type": "address" },
      { "indexed": false, "name": "liquidityRate", "internalType": "uint256", "type": "uint256" },
      { "indexed": false, "name": "stableBorrowRate", "internalType": "uint256", "type": "uint256" },
      { "indexed": false, "name": "variableBorrowRate", "internalType": "uint256", "type": "uint256" },
      { "indexed": false, "name": "liquidityIndex", "internalType": "uint256", "type": "uint256" },
      { "indexed": false, "name": "variableBorrowIndex", "internalType": "uint256", "type": "uint256" }
    ],
    "anonymous": false
  },
  {
    "type": "event",
    "name": "ReserveUsedAsCollateralDisabled",
    "inputs": [
      { "indexed": true, "name": "reserve", "internalType": "address", "type": "address" },
      { "indexed": true, "name": "user", "internalType": "address", "type": "address" }
    ],
    "anonymous": false
  },
  {
    "type": "event",
    "name": "ReserveUsedAsCollateralEnabled",
    "inputs": [
      { "indexed": true, "name": "reserve", "internalType": "address", "type": "address" },
      { "indexed": true, "name": "user", "internalType": "address", "type": "address" }
    ],
    "anonymous": false
  },
  {
    "type": "event",
    "name": "Supply",
    "inputs": [
      { "indexed": true, "name": "reserve", "internalType": "address", "type": "address" },
      { "indexed": false, "name": "user", "internalType": "address", "type": "address" },
      { "indexed": true, "name": "onBehalfOf", "internalType": "address", "type": "address" },
      { "indexed": false, "name": "amount", "internalType": "uint256", "type": "uint256" },
      { "indexed": true, "name": "referralCode", "internalType": "uint16", "type": "uint16" }
    ],
    "anonymous": false
  },
  {
    "type": "event",
    "name": "SwapBorrowRateMode",
    "inputs": [
      { "indexed": true, "name": "reserve", "internalType": "address", "type": "address" },
      { "indexed": true, "name": "user", "internalType": "address", "type": "address" },
      { "indexed": false, "name": "interestRateMode", "internalType": "enum DataTypes.InterestRateMode", "type": "uint8" }
    ],
    "anonymous": false
  },
  {
    "type": "event",
    "name": "UserEModeSet",
    "inputs": [
      { "indexed": true, "name": "user", "internalType": "address", "type": "address" },
      { "indexed": false, "name": "categoryId", "internalType": "uint8", "type": "uint8" }
    ],
    "anonymous": false
  },
  {
    "type": "event",
    "name": "Withdraw",
    "inputs": [
      { "indexed": true, "name": "reserve", "internalType": "address", "type": "address" },
      { "indexed": true, "name": "user", "internalType": "address", "type": "address" },
      { "indexed": true, "name": "to", "internalType": "address", "type": "address" },
      { "indexed": false, "name": "amount", "internalType": "uint256", "type": "uint256" }
    ],
    "anonymous": false
  }
]

```


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