Swaylend is a decentralized lending protocol deployed on Fuel, designed with modularity, safety, and capital efficiency in mind. It offers isolated markets for each asset pair, allowing precise risk control, and supports customizable parameters such as interest rate curves, collateral factors, and liquidation thresholds. Unlike traditional pooled lending systems, Swaylend enables tailor-made market configs per asset, enabling sharper control over risk and volatility. Built entirely with Fuel’s UTXO-based architecture, the protocol takes advantage of parallel execution and native account abstraction, resulting in gas-efficient and scalable lending mechanics. Swaylend is one of the first major lending protocols on Fuel — paving the way for the ecosystem’s DeFi stack.
Client:
Fuel ecosystem grant
Our Role:
Core developer, Smart contract engineer
Year:
2024
Service Provided:
Smart contract development, Lending architecture
We started from scratch with lending logic tailored to Fuel’s unique design. Each market in Swaylend is isolated — this allows deploying multiple lending pairs independently, reducing systemic risk and enabling parameter flexibility per asset.
I designed and implemented core modules: deposit/borrow logic, collateral handling, interest rate math, and liquidation mechanics. The system uses Fuel’s native scripting and storage models, requiring a rethink of classic Solidity-based lending patterns.
Beyond contracts, I worked on protocol-level simulations to test market sensitivity and capital flow dynamics. The result was a production-ready MVP, optimized for Fuel’s low-level constraints and parallel execution environment.
This project was a deep dive into designing lending mechanics under UTXO-model constraints — and it laid the foundation for future integrations across the Fuel ecosystem.
