UniCarbon

🌱 UniCarbon is a ReFi platform on Kadena EVM that tokenizes carbon credits as ERC20 tokens and issues NFT certificates for offsets. Companies can buy, trade, and retire credits on-chain, creating a transparent, auditable, and verifiable system for carbon compliance and sustainability reporting, bridging blockchain technology with climate action.

UniCarbon is powered by Kadena EVM, where we wrote Solidity smart contracts to tokenize carbon credits as ERC20 tokens and issue offset certificates as ERC721 NFTs. The CarbonCredit contract represents government-issued credits, while CarbonOffsetManager handles sales, offsets, and certificate minting.

We used Create2 deterministic deployment on Kadena testnet to ensure predictable contract addresses. Contract interactions such as buying credits, offsetting, and minting NFTs are managed with ethers.js.

For the backend, we built a Hono.js API that connects companies and admins to the blockchain. This service integrates with Supabase + Prisma ORM to persist company profiles, transactions, and NFT metadata in a relational database for off-chain querying.

Events emitted from smart contracts (like CreditsPurchased and CreditsOffset) are parsed by the backend to verify on-chain actions and sync with the database. This hybrid approach ensures regulatory-grade auditability while keeping the system decentralized.

Frontend dashboards (planned) will let companies register, buy credits, track balances, and view NFT certificates that prove compliance. The combination of blockchain transparency with database-driven insights makes UniCarbon both developer-friendly and regulator-ready