@lending:apy

Current APY of a lending-market reserve as a decimal fraction (2.04% is 0.0204), compounded the way the protocol accrues. Pass supply for the deposit rate or borrow for the variable borrow rate.

⚗️ Experimental — available at next.evmcrispr.com.

Returns: number

Syntax

@lending:apy(token side adapter?)

Arguments

Name	Type	Description
token	address	Reserve token to inspect (use @token(SYM))
side	string	supply for the deposit rate, borrow for the borrow rate
[adapter]	lending-adapter	Lending protocol: AaveV3, Spark or CompoundV3 (default: the best available on the chain)

Examples

# Print the WXDAI deposit APY (0.02 means 2%)
print "WXDAI supply APY:" @lending:apy(0xe91D153E0b41518A2Ce8Dd3D7944Fa863463a97d supply)

# Print the variable borrow APY
print "WXDAI borrow APY:" @lending:apy(0xe91D153E0b41518A2Ce8Dd3D7944Fa863463a97d borrow)

On-chain face (@apy!)

The market, the protocol and the reserve listing are composition-time facts: which adapter answers comes from its address book, the sim-mode filter and a getReserveData check, none of which the chain can decide mid-batch. What defers is the rate itself.

The compounding is the same computation as the plain face, expressed in operands: one unit plus the per-period rate, raised to the number of periods in fixed point, minus the unit. Aave quotes an annualized ray rate, so it divides down to per-second first; Comet quotes per second already, in wad, and reaches its rate through a live utilization read. The result carries the protocol's own scale, so >= 0.05 compares against 5e25 on a ray market rather than rounding to nothing.

Being readable off-chain does not imply being expressible on-chain, so an adapter declares the two capabilities separately. Where a rate has no composition the adapter omits the slot and the face names the protocol that cannot do it, instead of quietly meaning something else.

See Also