Ermitage
Index

Obs. 03

Underground Society

Buy now, pay later for NFTs

Engagement
Protocol & backend engineering
Period
2022 — 2023
Domain
Web3 · Lending
Scope
On-chain programs · Backend · Loan servicing

A buy-now-pay-later protocol for NFTs, shipped and verified on Solana mainnet. A buyer puts down part of the price, the protocol finances the balance from its own lending pools and holds the asset as collateral until it is paid off. Ermitage wrote the on-chain programs, the backend that signs and services every loan, and the automation that handles repayment and liquidation.

Architecture

On-chain programs · Backend · Loan servicing

StorefrontServicingOn-chainMarketplaceMy vaultSigning APIPricingLiquidationVault programLending poolsAuction house

01

Problem

Buying an NFT meant paying the full price up front, which priced most buyers out of the collections they wanted. Financing one is harder than it sounds. Capital has to come from somewhere. The asset has to be held such that neither side can remove it. And if the collateral loses value, the position has to unwind autonomously.

02

Approach

The buyer puts down a fraction of the price. The protocol draws the balance from its own liquidity pools, buys the asset on whichever marketplace holds it, and freezes it as collateral. From there the buyer repays in instalments and redeems the asset, or the position liquidates once the collateral's valuation breaches its threshold. Every transition is enforced by the on-chain programs, so the terms outlive the operator.

03

Servicing

A loan that exists on-chain still has to be serviced, and that is where most of the engineering went. The backend signs every transaction, prices collateral across several marketplaces, and runs the scheduled work that keeps positions solvent: repayment checks, fee distribution back to the pools, liquidation at threshold, and disposal of recovered collateral into the market. Servicing is what determines whether a lending product survives a drawdown.