Silo

ISilo

Silo is the main component of the protocol. It implements lending logic, manages and isolates risk, acts as a vault for assets, and performs liquidations. Each Silo is composed of the unique asset for which it was created (ie. UNI) and bridge assets (ie. ETH and SiloDollar). There may be multiple bridge assets at any given time.

Main Silo contact that inherits from Base contract. It implements all user/UI facing methods.

Methods

ASSET_DECIMAL_POINTS

function ASSET_DECIMAL_POINTS() external view returns (uint256)

Returns

Name	Type	Description
_0	uint256	undefined

VERSION

function VERSION() external view returns (uint256)

It tells us which SiloRepository.siloFactory(version) created this Silo

Returns

Name	Type	Description
_0	uint256	undefined

accrueInterest

function accrueInterest(address _asset) external nonpayable

Function to update interests for _asset token since the last saved state

Parameters

Name	Type	Description
_asset	address	The address of the token to be updated

allSiloAssets

function allSiloAssets(uint256) external view returns (address)

Parameters

Name	Type	Description
_0	uint256	undefined

Returns

Name	Type	Description
_0	address	undefined

assetInterestData

function assetInterestData(address) external view returns (uint256 harvestedProtocolFees, uint256 protocolFees, uint64 interestRateTimestamp, enum IBaseSilo.AssetStatus status)

Parameters

Name	Type	Description
_0	address	undefined

Returns

Name	Type	Description
harvestedProtocolFees	uint256	undefined
protocolFees	uint256	undefined
interestRateTimestamp	uint64	undefined
status	enum IBaseSilo.AssetStatus	undefined

assetStorage

function assetStorage(address _asset) external view returns (struct IBaseSilo.AssetStorage)

Get asset storage data

Parameters

Name	Type	Description
_asset	address	asset address

Returns

Name	Type	Description
_0	IBaseSilo.AssetStorage	AssetStorage struct

borrow

function borrow(address _asset, uint256 _amount) external nonpayable

Borrow _amount of _asset tokens from the Silo to msg.sender

Parameters

Name	Type	Description
_asset	address	The address of the token to borrow
_amount	uint256	The amount of the token to borrow

borrowFor

function borrowFor(address _asset, address _borrower, address _receiver, uint256 _amount) external nonpayable

Router function to borrow _amount of _asset tokens from the Silo for the _receiver

Parameters

Name	Type	Description
_asset	address	The address of the token to borrow
_borrower	address	The address of the debt tokens receiver
_receiver	address	The address of the asset receiver
_amount	uint256	The amount of the token to borrow

borrowPossible

function borrowPossible(address _asset, address _borrower) external view returns (bool)

Check if borrowing an asset for given account is possible

Borrowing an asset that has been already deposited (and vice versa) is disallowed

Parameters

Name	Type	Description
_asset	address	asset we want to deposit
_borrower	address	borrower address

Returns

Name	Type	Description
_0	bool	true if asset can be borrowed by borrower

deposit

function deposit(address _asset, uint256 _amount, bool _collateralOnly) external nonpayable

Deposit _amount of _asset tokens from msg.sender to the Silo

Parameters

Name	Type	Description
_asset	address	The address of the token to deposit
_amount	uint256	The amount of the token to deposit
_collateralOnly	bool	True if depositing collateral only

depositFor

function depositFor(address _asset, address _depositor, uint256 _amount, bool _collateralOnly) external nonpayable

Router function to deposit _amount of _asset tokens to the Silo for the _depositor

Parameters

Name	Type	Description
_asset	address	The address of the token to deposit
_depositor	address	The address of the recipient of collateral tokens
_amount	uint256	The amount of the token to deposit
_collateralOnly	bool	True if depositing collateral only

depositPossible

function depositPossible(address _asset, address _depositor) external view returns (bool)

Check if depositing an asset for given account is possible

Depositing an asset that has been already borrowed (and vice versa) is disallowed

Parameters

Name	Type	Description
_asset	address	asset we want to deposit
_depositor	address	depositor address

Returns

Name	Type	Description
_0	bool	true if asset can be deposited by depositor

flashLiquidate

function flashLiquidate(address[] _users, bytes _flashReceiverData) external nonpayable returns (address[] assets, uint256[][] receivedCollaterals, uint256[][] shareAmountsToRepay)

this methods does not requires to have tokens in order to liquidate user

during liquidation process, msg.sender will be notified once all collateral will be send to him msg.sender needs to be IFlashLiquidationReceiver

Parameters

Name	Type	Description
_users	address[]	array of users to liquidate
_flashReceiverData	bytes	this data will be forward to msg.sender on notification

Returns

Name	Type	Description
assets	address[]	array of all processed assets (collateral + debt, including removed)
receivedCollaterals	uint256[][]	seizedCollaterals[userId][assetId] => amount amounts of collaterals send to _flashReceiver
shareAmountsToRepay	uint256[][]	shareAmountsToRepaid[userId][assetId] => amount required amounts of debt to be repaid

getAssets

function getAssets() external view returns (address[] assets)

Returns all initialized (synced) assets of Silo including current and removed bridge assets

Returns

Name	Type	Description
assets	address[]	array of initialized assets of Silo

getAssetsWithState

function getAssetsWithState() external view returns (address[] assets, struct IBaseSilo.AssetStorage[] assetsStorage)

Returns all initialized (synced) assets of Silo including current and removed bridge assets with corresponding state

Returns

Name	Type	Description
assets	address[]	array of initialized assets of Silo
assetsStorage	IBaseSilo.AssetStorage[]	array of assets state corresponding to assets array

harvestProtocolFees

function harvestProtocolFees(address[] _assets) external nonpayable

harvest protocol fees from an array of assets

Parameters

Name	Type	Description
_assets	address[]	array of assets we want to harvest fees from

initAssetsTokens

function initAssetsTokens() external nonpayable

this is exposed only for test purposes, but it is safe to leave it like that

interestData

function interestData(address _asset) external view returns (struct IBaseSilo.AssetInterestData)

Get asset interest data

Parameters

Name	Type	Description
_asset	address	asset address

Returns

Name	Type	Description
_0	IBaseSilo.AssetInterestData	AssetInterestData struct

isSolvent

function isSolvent(address _user) external view returns (bool)

Calculates solvency of an account

Parameters

Name	Type	Description
_user	address	wallet address for which solvency is calculated

Returns

Name	Type	Description
_0	bool	true if solvent, false otherwise

repay

function repay(address _asset, uint256 _amount) external nonpayable

Repay _amount of _asset tokens from msg.sender to the Silo

Parameters

Name	Type	Description
_asset	address	The address of the token to repay
_amount	uint256	amount of asset to repay, includes interests

repayFor

function repayFor(address _asset, address _borrower, uint256 _amount) external nonpayable

Allows to repay in behalf of borrower to execute liquidation

Parameters

Name	Type	Description
_asset	address	The address of the token to repay
_borrower	address	The address of the user to have debt tokens burned
_amount	uint256	amount of asset to repay, includes interests

siloAsset

function siloAsset() external view returns (address)

Returns

Name	Type	Description
_0	address	undefined

siloRepository

function siloRepository() external view returns (contract ISiloRepository)

Get Silo Repository contract address

Returns

Name	Type	Description
_0	contract ISiloRepository	undefined

state

function state(address) external view returns (contract IShareToken collateralToken, contract IShareToken collateralOnlyToken, contract IShareToken debtToken, uint256 totalDeposits, uint256 collateralOnlyDeposits, uint256 totalBorrowAmount)

Parameters

Name	Type	Description
_0	address	undefined

Returns

Name	Type	Description
collateralToken	contract IShareToken	undefined
collateralOnlyToken	contract IShareToken	undefined
debtToken	contract IShareToken	undefined
totalDeposits	uint256	undefined
collateralOnlyDeposits	uint256	undefined
totalBorrowAmount	uint256	undefined

syncBridgeAssets

function syncBridgeAssets() external nonpayable

Synchronize current bridge assets with Silo

This function needs to be called on Silo deployment to setup all assets for Silo. It needs to be called every time a bridged asset is added or removed. When bridge asset is removed, depositing and borrowing should be disabled during asset sync.

utilizationData

function utilizationData(address _asset) external view returns (struct IBaseSilo.UtilizationData data)

helper method for InterestRateModel calculations

Parameters

Name	Type	Description
_asset	address	undefined

Returns

Name	Type	Description
data	IBaseSilo.UtilizationData	undefined

withdraw

function withdraw(address _asset, uint256 _amount, bool _collateralOnly) external nonpayable

Withdraw _amount of _asset tokens from the Silo to msg.sender

Parameters

Name	Type	Description
_asset	address	The address of the token to withdraw
_amount	uint256	The amount of the token to withdraw
_collateralOnly	bool	True if withdrawing collateral only deposit

withdrawFor

function withdrawFor(address _asset, address _depositor, address _receiver, uint256 _amount, bool _collateralOnly) external nonpayable

Router function to withdraw _amount of _asset tokens from the Silo for the _depositor

Parameters

Name	Type	Description
_asset	address	The address of the token to withdraw
_depositor	address	The address of the collateral tokens source account
_receiver	address	The address of the asset receiver
_amount	uint256	The amount of the token to withdraw
_collateralOnly	bool	True if withdrawing collateral only deposit

Events

Borrow

event Borrow(address indexed asset, address indexed user, uint256 amount)

Emitted on asset borrow

Parameters

Name	Type	Description
asset indexed	address	undefined
user indexed	address	undefined
amount	uint256	undefined

Deposit

event Deposit(address indexed asset, address indexed depositor, uint256 amount, bool collateralOnly)

Emitted when deposit is made

Parameters

Name	Type	Description
asset indexed	address	undefined
depositor indexed	address	undefined
amount	uint256	undefined
collateralOnly	bool	undefined

Liquidate

event Liquidate(address indexed asset, address indexed user, uint256 shareAmountRepaid, uint256 seizedCollateral)

Emitted on user liquidation

Parameters

Name	Type	Description
asset indexed	address	undefined
user indexed	address	undefined
shareAmountRepaid	uint256	undefined
seizedCollateral	uint256	undefined

Repay

event Repay(address indexed asset, address indexed user, uint256 amount)

Emitted on asset repay

Parameters

Name	Type	Description
asset indexed	address	undefined
user indexed	address	undefined
amount	uint256	undefined

Withdraw

event Withdraw(address indexed asset, address indexed depositor, address indexed receiver, uint256 amount, bool collateralOnly)

Emitted when withdraw is made

Parameters

Name	Type	Description
asset indexed	address	undefined
depositor indexed	address	undefined
receiver indexed	address	undefined
amount	uint256	undefined
collateralOnly	bool	undefined

Errors

IncorrectDataLength

error IncorrectDataLength()