Adapter system

Four operational interfaces plus one presentation interface define every point where the core engine reaches outside itself.

IAssetAdapter

Handles collateral custody.

Reference implementations: ERC20Adapter, ERC721Adapter, ERC1155Adapter, issuer-specific adapters for permissioned RWA tokens.


interface IAssetAdapter {
    function escrow(address from, uint256 amountOrId) external;
    function release(address to, uint256 amountOrId) external;
    function isTransferable(address from, address to, uint256 amountOrId)
        external view returns (bool);
}

IOracleAdapter

Handles pricing.

Reference implementations: UniswapV3TWAPAdapter, ChainlinkAdapter, ChainlinkEquityFeedAdapter, NAVOracleAdapter, ManualOracleAdapter.


interface IOracleAdapter {
    /// isTrusted covers staleness, L2 sequencer liveness, AND session-awareness
    /// (e.g. equity feeds outside trading windows).
    function getPrice()
        external view returns (uint256 price, bool isTrusted, uint256 updatedAt);
 
    function getHistoricalPrice(uint256 secondsAgo)
        external view returns (uint256);
}

The engine does not need to know why a price is untrusted — only whether to act on it. Untrusted prices feed the circuit breaker.

IComplianceAdapter

Handles eligibility. Optional — markets with no compliance requirement set complianceAdapter == address(0) and skip checks.

Reference implementations: ERC3643ComplianceAdapter, IssuerAllowlistAdapter, JurisdictionGeofenceAdapter.


interface IComplianceAdapter {
    function isEligible(address participant) external view returns (bool);
}

Checked at loan origination and, for transferable positions, at every position transfer.

ILiquidationAdapter

Handles default resolution.

Reference implementations: DEXSwapLiquidationAdapter, NFTAuctionLiquidationAdapter, IssuerRedemptionLiquidationAdapter.


interface ILiquidationAdapter {
    /// recoveredForLP  — value taken to satisfy debt + penalty
    /// returnedToHolder — surplus returned to the position holder
    function liquidate(uint256 loanId, uint256 debtOwed)
        external returns (uint256 recoveredForLP, uint256 returnedToHolder);
 
    function isAsynchronous() external view returns (bool);
 
    /// Only meaningful when isAsynchronous() == true
    function cureWindowSeconds() external view returns (uint256);
}

Gradual liquidation is an interface contract

Gradual liquidation is not a separate adapter. Every ILiquidationAdapter must return both recovered and returned amounts. That forces surplus accounting:

Collateral type	How surplus is returned
Divisible ERC20	Real tokens back to holder
Indivisible NFT	Cash side-payment (ETH/stable) from available liquidity
Issuer redemption	Whatever settlement yields after debt is satisfied

IPositionAdapter

Handles how a loan is represented and who may act on it.


interface IPositionAdapter {
    function mint(address to, uint256 loanId) external;
    function ownerOf(uint256 loanId) external view returns (address);
    function burn(uint256 loanId) external; // repay or liquidation
}

Tiers: Standard (no token), Soulbound ERC721, Transferable ERC721. Details: Position adapters.