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LP-0054Finallendingcreditundercollateralizedreputationdefi

LP-054: Credit Lending

Abstract

Lux Credit Lending extends the isolated lending market framework (LP-044) with reputation-based credit scoring. Borrowers with established on-chain history (Karma score, LP-056) can access reduced collateral requirements -- down to 50% LTV compared to the standard 80-86%. Credit tiers are non-transferable and decay with inactivity. The protocol maintains a first-loss insurance tranche funded by the interest rate premium on credit loans.

Specification

Credit Tiers

| Tier | Min Karma | Max LTV | Rate Premium | Description |
|---|---|---|---|---|
| Standard | 0 | 86% | 0% | Same as LP-044 |
| Bronze | 100 | 80% | +50 bps | Light history |
| Silver | 500 | 65% | +100 bps | Established borrower |
| Gold | 2000 | 50% | +200 bps | Proven track record |

Higher LTV means lower collateral required (Gold tier borrowers post 50% collateral for 100% loan value).

Karma Integration

The borrower's Karma score (LP-056) determines their tier:


function getCreditTier(address borrower) public view returns (uint8) {
    uint256 karma = IKarma(karmaContract).scoreOf(borrower);
    if (karma >= 2000) return TIER_GOLD;
    if (karma >= 500)  return TIER_SILVER;
    if (karma >= 100)  return TIER_BRONZE;
    return TIER_STANDARD;
}

First-Loss Tranche

The rate premium on credit loans funds a first-loss insurance pool:

Liquidation

Credit loans have the same liquidation mechanics as LP-044, but with tighter monitoring:

Credit Default

If a credit loan becomes insolvent (bad debt):

1. Insurance reserve absorbs the loss (up to reserve balance)

2. Borrower's Karma score is reduced by 50%

3. Borrower is downgraded to Standard tier for 90 days

4. Default event is recorded on-chain (permanent)

Borrower Requirements

To access credit tiers above Standard:

Security Considerations

1. Karma gaming: artificial activity to inflate Karma is mitigated by the decay function and activity quality weighting in LP-056.

2. Insurance underfunding: if defaults exceed the insurance reserve, standard lenders bear the loss. The 5% target is calibrated to historical DeFi default rates.

3. Tier manipulation: tier is checked at borrow time. A borrower whose Karma drops cannot open new credit loans but existing loans remain at their original terms.

Reference

| Resource | Location |
|---|---|
| Credit lending contracts | github.com/luxfi/standard/contracts/lending/credit/ |
| Credit manager | CreditManager.sol |
| Karma integration | LP-056 |
| Base lending | LP-044 |

Copyright

Copyright (C) 2024-2026, Lux Partners Limited. All rights reserved.

Licensed under the MIT License.