Inspiration

Inspiration from project food waste and another waste control in Indonesia, but in this project, we truly integrate Web3 into a food waste minimization system to eliminate greenwashing and ensure verifiable impact reporting.

What it does

If food waste can be minimized, we can have profit with management productive food waste and high result from this fluctuation. ReFood Protocol acts as a decentralized verification layer that converts restaurant food waste reduction data into a cryptographically auditable public record and a dynamic on-chain reputation using a triple-verification pipeline (IPFS evidence anchoring, independent waste hauler dual attestation, and robust z-score anomaly screening via MAD)[.

How we built it

Frontend & Backend: Built using Next.js, Node.js, Express, and MongoDB Atlas to handle venue dashboards and off-chain data processing.
Decentralized Storage Scale photographs are pinned to IPFS via Pinata to generate immutable Content Identifiers (CIDs).
Smart Contracts: Developed in Solidity (ReFoodProtocol.sol and ReFoodSoulboundBadge.sol) and deployed on public testnets (Polygon Amoy / Arbitrum Sepolia) using cryptographic payload hashing keccak256.

Challenges we ran into

Ensuring non-deterministic JSON object ordering during payload hashing, which we resolved by implementing strict canonical serialization. We also managed robust statistical anomaly screening using Median Absolute Deviation MAD to protect against extreme outliers and data manipulation.

Accomplishments that we're proud of

Successfully implementing a fully functional MVP framework combining Web2 operational reporting with Web3 cryptographic anchoring and dynamic non-transferable Soulbound Tokens (SBTs) that update automatically upon verification.

What we learned

We gained deep practical insights into combining traditional database validation with smart contract dual-attestation logic, ensuring decentralized transparency without relying on complex, speculative tokenomics.

What's next for ReFood

Expanding the protocol's reach from commercial HoReCa (Hotel, Restaurant, Café) sectors down to residential communities through decentralized local waste banks (Bank Sampah) acting as validation nodes.