Lending Pool: Overview

AgamaLendingPool is the core contract of the system. It manages deposits, withdrawals, borrowing, repayment, and liquidation, while delegating collateral-specific logic to per-tranche adapters.

Purpose

• Hold the main USDr liquidity and mint agYLD receipts (ERC-4626).
• Abstract collateral through adapters so pool logic is asset-agnostic.
• Accrue interest using an index-based model (two-slope kink, Aave/Compound style).
• Enforce risk parameters per market (LTV, liquidation threshold, oracle staleness) and at the pool level (borrow cap, supply cap).
• Coordinate single-step atomic liquidations with the Stability Pool.

What is agYLD?

agYLD is the receipt you get when you deposit USDr into the Lending Pool. It's a standard ERC-4626 yield-bearing token: your balance stays fixed, but its redeem value in USDr grows over time as borrowers pay interest.

Example: you deposit 1,000 USDr → you receive a stack of agYLD worth 1,000 USDr. One year later, at 8% lender APY, the same agYLD is worth 1,080 USDr when you withdraw. No claim, no rebase.

agYLD has 24 decimals (18 underlying + 6 ERC-4626 offset). It is transferable and composable across Rayls DeFi. Yield is delivered through a rising redeem rate (liquidityIndex), not through rebasing balances.

Parameters

Two categories, both governance-controlled through the 48-hour timelock:

• Pool-wide parameters: supplyCap, borrowCap, MIN_BORROW_AMOUNT, withdrawalsPaused, IRM curve.
• Fee parameters: vaultOpeningFee (default 0), originationFeeBps (default 0), reserveFactorBps (default 1000 = 10%).

There is no on-chain liquidation grace period — V1 liquidations are atomic. There is also no deposit fee on the lender side; lenders mint agYLD 1:1 to the underlying USDr at the current share price.

Per-adapter risk parameters (MAX_LTV, LIQUIDATION_THRESHOLD, LIQUIDATION_BONUS, ORACLE_STALENESS_MAX) live on the adapter itself — one set per market.

Per-market risk parameters

Each tranche ships with its own risk profile. Senior and Junior markets are calibrated differently because they sit at different points of the credit waterfall:

ORACLE_STALENESS_MAX is per-adapter and governance-tunable. The deploy script ships with 24 hours as the constructor default; the current live deployment on Rayls testnet has been governance-bumped to 7 days across all six adapters to give the oracle pipeline more slack during demos. Any read or write that depends on the oracle reverts with OracleStale() if the oracle hasn't been updated within the window.

Per-market debt isolation

The DebtToken tracks borrower debt scoped to (user, adapter). Two consequences worth highlighting:

• A borrower's debt on jCONDO is completely independent of their debt on sRESOLV. Health factors, liquidations, and repayment schedules are evaluated per market.
• The aggregate DebtToken.totalSupply() (no args) drives the pool-wide utilisation that the IRM uses to set the borrow APR. So markets share a single rate even though they have isolated debt.

DebtToken.balanceOf(user, adapter) → debt on this market
DebtToken.balanceOf(user)          → debt across all markets the user touches
DebtToken.totalSupply(adapter)     → outstanding debt on this market
DebtToken.totalSupply()            → outstanding debt protocol-wide

Collateral adapters

Adapters are pluggable contracts that expose a uniform interface (IAssetAdapter) to the Lending Pool. A new adapter is whitelisted by governance via registerAdapter(address). The Lending Pool never holds RWA tokens directly; the adapter is the custodian.

The protocol currently ships with 6 active adapters, all instances of AmFiAdapter parameterised for Senior or Junior of three issuer pools (Resolvi, Digcap, Sector Condo). Additional adapters — different issuers, different risk profiles, even different asset classes — can be added without redeploying the Lending Pool.

Core mechanics

Five sub-flows:

1. Deposit & agYLD minting

User deposits USDr; agYLD is minted at the current share price (1:1 only on the very first deposit). No deposit fee in V1. The agYLD then appreciates as borrowers pay interest, through the rising liquidityIndex.

2. Vault position & collateral

Borrowers must call openVaultPosition() once (paying vaultOpeningFee, currently 0). They then use depositAsset(adapter, data) / withdrawAsset(adapter, data) to manage their collateral on a specific market. Collateral lives at the adapter, not at the pool.

3. Borrowing

borrow(adapter, data, amount) mints DebtToken scoped to (user, adapter), indexed against the reserve's usageIndex, and transfers USDr to the borrower. Health-factor validation runs against that one market's collateral and that one market's debt.

4. Repayment

repay(adapter, data, amount) burns scoped DebtToken and pulls USDr back from the user. Residual dust below MIN_BORROW_AMOUNT is rejected. Repaying on one market doesn't affect the borrower's debt on any other market.

5. Liquidation

Single atomic liquidate(adapter, user, data) call when HF < 1 on a given market. No on-chain grace period: the seizure happens in one transaction, scoped to the (user, adapter) pair. Gated by LIQUIDATION_PROXY_ROLE — held by the LiquidationProxy and by the Stability Pool — and the proxy itself is manager-gated in V1. See Stability Pool → Liquidations for the end-to-end flow.

Liquidity buffer

Idle USDr sits inside the agYLD contract and is not currently routed to an external yield vault. The utilisation-driven IRM already compensates lenders during low utilisation; an idle-yield layer can be added without changing the pool's external surface.

Interactions

Continue to Functions for the complete reference.