NFTlend.xyz

The end of searching for liquidity.

Design statement

How might we improve liquidity for NFT owners, so that they have immediate access to funds without having to first find a lender, agree to a deal, or sell below market?

Overview

NFTlend is building the first automated market maker for instant, permissionless NFT-backed loans.

• Borrowers escrow NFTs to instantly access over-collateralized, fixed-term loans priced at the project floor.

• Lenders deposit assets into the lending pool to receive yield generated from borrower interest payments.

• Liquidators repay any loan defaults (those expired or undercollateralized) to purchase the underlying NFT at a discount.

Live dApp

Deployed on Ropsten and IPFS: ropsten.nftlend.xyz.

Note that test DAI, USDC or WETH is required to interact with the protocol.

Contact me on Twitter @niftrr with your Ethereum address and I will send you some.

Video demo

Protocol system design

System diagram

Summary

• Lending Pool is the main contract of the protocol exposing all user interaction endpoints; deposit, withdraw, borrow, repay and liquidate.

• Collateral Manager contract handles the escrow of NFTs and loan creation.

• nTokens are interest-bearing derivative tokens that are minted and burned upon the deposit and withdraw of asset tokens to / from the Lending Pool at a 1:1 ratio.

• debtTokens are non-transferable derivative tokens that are minted and burned upon the borrow and repay of loans to the Lending Pool a 1:1 ratio with the asset token repayment amount. It is the ratio of debtTokens to nTokens, updated at every user interaction, that is used to calculate the interest generated by the protocol.

• NFT Pricing Oracles are used to update NFT project floor prices, to price new loans and signal if the underlying loan collateral price falls below threshold for liquidation.

• Token Pricing Oracles are used to calculate exchange rates from the NFT Pricing Oracles, priced in ETH, to other loaned assets; DAI and USDC.

• Libraries contain reusable code, refactored from the protocol to save gas.

• Configurator is the admin contract used to set / update protocol variables.

Design pattern decisions

Link to detail on design pattern decisions.

Security measures

Link to detail on avoiding common attacks.

User interface

Landing page

Dashboard

Borrow

Lend

Liquidate

Asset

Directory structure

.
├── assets                                      # README assets
├── docs                                        # Documentation 
│   ├── avoiding_common_attacks.md              # Security measures 
│   ├── deployed_address.txt                    # Deployed smart contract addresses
│   └── design_pattern_decisions.md             # Design patterns 
├── interface                                   # Front-end interface
│   ├── components                              # React components 
│   ├── hooks                                   # React hooks 
│   ├── App.jsx                                 # React app
│   ├── AppContext.jsx                          # React app state management
│   ├── LICENCE                          
│   ├── README.md                        
│   └── ...   
├── v1-core                                     # Protocol 
│   ├── contracts                               # Smart contracts
│   │   ├── interfaces                          # Interfaces
│   │   │   ├── ICollateralManager.sol          # CollateralManager interface
│   │   │   ├── IDebtToken.sol                  # DebtToken interface
│   │   │   ├── ILendingPool.sol                # LendingPool interface
│   │   │   └── INToken.sol                     # NToken interface
│   │   ├── libraries                           # Libraries
│   │   │   ├── DataTypes.sol                   # DataTypes library
│   │   │   └── ReserveLogic.sol                # ReserveLogic library
│   │   ├── mocks                               # Mocks
│   │   │   ├── AssetToken.sol                  # ERC20 contract
│   │   │   └── NFT.sol                         # ERC721 contract
│   │   ├── CollateralManager.sol               # CollateralManager contract
│   │   ├── Configurator.sol                    # Configurator contract
│   │   ├── DebtToken.sol                       # DebtToken contract
│   │   ├── LendingPool.sol                     # LendingPool contract
│   │   ├── LendingPoolEvents.sol               # LendingPoolEvents contract
│   │   ├── LendingPoolStorage.sol              # LendingPoolStorage contract
│   │   ├── NToken.sol                          # NToken contract
│   │   └── TokenPriceOracle.sol                # TokenPriceOracle contract (WIP)
│   ├── scripts                                 # Scripts 
│   │   └── deploy.js                           # Deployment script
│   ├── test                                    # Unit tests
│   ├── LICENCE  
│   ├── README.md      
│   └── ...  
└── ...

Local development

Protocol

Follow the instructions in v1-core/README.md.

Interface

Follow the instruction in interface/README.md.

Next steps

• Connect with Opensea Chainlink external adapter for NFT floor prices. (Note: external adapter development already complete and being supported by node operators).
• Connect to Chainlink data feeds for price-feed integration.
• Add logic to generage interest payment accrual to lenders.
• Update liquidate function to trigger a timed auction with a feature to allow the original owner to purchase back their deposited price at the cost of the outstanding debt plus a fee; to provide better protection and compensation for NFT owners during liquidation events.
• Add flash loan functionality.
• Audit smart contracts.
• Update the Interface in terms of UX, with full test coverage.

Licensing

The primary license for both the NFTlend V1 Core and Interface is the Business Source License 1.1 (BUSL-1.1), see:

• ./v1-core/LICENSE,
• ./interface/LICENSE.

Public Ethereum Address

niftrr.eth