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Rates Guide
- How to query historical data?
- Coming soon
- Coming soon
The variable borrow rate is determined is determined programatically based on the interest rate strategy for a reserve. The InterestRateStrategy for each reserve can be queried from the AaveProtocolDataProvider or UiPoolDataProvider view contracts.
Whenever an action occurs on a reserve (supply, borrow, repay, withdraw, liquidation, etc.), updateInterestRates is called. Most reserves implement the DefaultInterestRateStrategy which updates variable borrow rates based on the variable rate slope parameters determined by Aave Governance and borrow utilitization of the reserve.
An exception to this is the Aave GHO facilitator which uses a custom implementation of the interest rate strategy, more details.
The stable borrow rate (for new borrows) is determined programatically based on the interest rate strategy for a reserve. The InterestRateStrategy for each reserve can be queried from the AaveProtocolDataProvider or UiPoolDataProvider view contracts.
Whenever an action occurs on a reserve (supply, borrow, repay, withdraw, liquidation, etc.), updateInterestRates is called. All stable borrow reserves implement the DefaultInterestRateStrategy which updates stable borrow rates based on the stable rate slope parameters determined by Aave Governance and borrow utilitization of the reserve.
The rate for each active stable borrower is stored in a mapping and can be queried from the getUserStableBorrowRate function.
In certain conditions, the stable borrow rate for a borrower can be rebalanced, see the FAQ for specific requirements in Aave V2 and V3.
The supply rate is determined is determined programatically based on the interest rate strategy for a reserve. The InterestRateStrategy for each reserve can be queried from the AaveProtocolDataProvider or UiPoolDataProvider view contracts.
Whenever an action occurs on a reserve (supply, borrow, repay, withdraw, liquidation, etc.), updateInterestRates is called. The supply rate is updated based on the weighted average of all variable and stable borrow rates minus the reserve factor, which is the percentage of borrow interest to the DAO treasury collector, determined by Aave Goveran
Variable borrow balances increase over time, based on a checkpointing variable called
variableBorrowIndex:VariableDebtToken.balanceOf(user) = VariableDebtToken.scaledBalanceOf(user) * Pool.getReserveData(underlyingTokenAddress).variableBorrowIndex
where
VariableDebtToken.scaledBalanceOf(user) = initialBorrowAmount / variableBorrowIndexAtTimeOfBorrow
variableBorrowIndex is shared across all variable borrowers and is updated on all reserve state updates (supply, borrow, withdraw, repay, liquidate, etc.) based on the current variable borrow rate and time since last update. The
variableBorrowIndex can be queried from the Pool.getReserveData(underlyingTokenAddress), AaveProtocolDataProvider.getReserveData(underlyingTokenAddress), or UiPoolDataProvider.getReservesData() functions.In Aave V3, all VariableDebtTokens contain a function
getPreviousIndex which can be used to calculate accrued interest:initialBorrowedAmount = VariableDebtToken.scaledBalanceOf(user) * VariableDebtToken.getPreviousIndex(user)
accruedInterest = VariableDebtToken.balanceOf(user) - initialBorrowedAmount
StableDebtToken.balanceOf(user) = StableDebtToken.principalBalanceOf(user) * accuredInterest
where
StableDebtToken.principalBalanceOf(user) is the initial borrow amount and accruedInterest is calculated here based on the rate and last update timestamp of an individual address.The rate and lastUpdateTimestamp for each active stable borrower are stored in mappings and can be queried from the getUserStableBorrowRate and getUserLastUpdated functions respectively.
The checkpointing for supply balances occurs through the
liquidityIndex variable:AToken.balanceOf(user) = AToken.scaledBalanceOf(user) * Pool.getReserveData(underlyingTokenAddress).liquidityIndex
where
AToken.scaledBalanceOf(user) = initialSupplyAmount / liquidityIndexAtTimeOfSupply
liquidityIndex is a variable shared across all suppliers and is updated on all reserve state updates (supply, borrow, withdraw, repay, liquidate, etc.) based on the current supply rate and time since last update. The
liquidityIndex can be queried from the Pool.getReserveData(underlyingTokenAddress), AaveProtocolDataProvider.getReserveData(underlyingTokenAddress), or UiPoolDataProvider.getReservesData() functions.In Aave V3, all ATokens contain a function
getPreviousIndex which can be used to calculate accrued interest:initialSuppliedAmount = AToken.scaledBalanceOf(user) * AToken.getPreviousIndex(user)
accruedInterest = AToken.balanceOf(user) - initialSuppliedAmount
The Aave Utilities SDK is an extension of ethers v5, which simplifies the process of querying Aave Protocol data through a blockhain RPC:
Live rates can queried from the Pool, AaveProtocolDataProvider, or UiPoolDataProvider smart contracts.
Rates queried from contracts are in RAY units (10^27) and are not compounded, see formatting rates to convert to compounded percentage form.
The protocol subgraphs are indexed GraphQL endpoints which can be used to query current reserve states.
Subgraph rates come directly from smart contracts: RAY units (10^27) and are not compounded, see formatting rates to convert to compounded percentage form.
Reserve Query
{
reserves {
name
underlyingAsset
liquidityRate
stableBorrowRate
variableBorrowRate
}
}
User Data Query (for stable borrow data)
{
userReserves(where: {user: "insert_lowercase_address_here"}){
reserve{
symbol
}
stableBorrowRate
stableBorrowLastUpdateTimestamp
}
}
Coming soon
Coming soon
All rates and indeces queried on-chain or from subgraphs are expressed in RAY units i.e. 10^27.
Supply and borrow rates queried on-chain or from subgraphs are not compounded. On the smart contract, borrow rates are compounded per second using a binomial approximation. Within each update action, supply rates are applied linearly, however, on an inter-action basis they experience the same compounding effect as the borrow rates, more details.
The Aave Utilities SDK formatting functions (used on the app.aave.com interface) computes the compounded supply and borrow rates using the formula shown below.
Incentive emissions are always non-compounded, they are applied to the scaled supply or borrow balance.
To convert the APR (non-compounded) to APY compounded per second, the formula is:
where the APY and APR are in decimal form (i.e. 2.5% = 0.025)
Last modified 1mo ago