AlgaeOS

AlgaeOS is a lightweight marketplace for real-world algae biomass. Buyers pay in PYUSD on Base Sepolia; sellers get instant, transparent receipts and can verify every purchase on Blockscout. The MVP ships with a simple catalog, a clean checkout, and two modes: “Simulation” (no gas, with Lit-based signing to prove order intent) and “Real” (on-chain purchase using PYUSD). To build trust, we surface public transaction links and a basic sales feed. With Pyth, we demonstrate price-aware UX (pull oracle updates) and a daily, provably-fair “green cashback” raffle using Pyth Entropy. The goal: show how stablecoin rails (PYUSD) + transparent infra (Blockscout) + reliable data (Pyth) can make small producers competitive, starting with algae biomass. The codebase is beginner-friendly, fully documented, and deployable in minutes.

Smart contracts in Solidity with Hardhat v3 on Base Sepolia implement a product catalog, PYUSD payments using ERC-20 approve and transferFrom, Pyth Pull Oracle via Hermes payloads with getUpdateFee and updatePriceFeeds, and Pyth Entropy for a daily cashback raffle. The repository includes unit tests with chai and a seed script that preloads inventory.

Frontend in Vite and React (JavaScript) integrates Rabby Wallet for Base Sepolia and ethers for contract calls. A Simulation path signs orders with Lit Protocol PKP and session signatures so judges can test flows without spending gas.

Blockscout provides public transparency. Each on-chain purchase links to the Base Sepolia explorer. A Recent purchases panel can optionally use the Blockscout App SDK for richer history and status.

Pyth powers price-aware UX. The client fetches price update payloads from Hermes, forwards them on-chain to update feeds, and reads fresh prices. Entropy supplies verifiable randomness for the raffle.

Payments use PYUSD from the official Paxos faucet for test tokens. Funds settle to a treasury address controlled by the seller.

Developer experience: Windows and pnpm, .env based configuration, readable contracts, minimal React components, and Vercel for hosting the frontend. Partner tech provides clear benefits: stable and user friendly payments with PYUSD, transparent verification with Blockscout, and trustworthy data and randomness with Pyth and Entropy.