Open House Archive
Welcome to the Open House Archive - your central repository for accessing all previous Open House buildathons and projects.

Instead of turning the blockchain into a fully opaque privacy layer (which undermines the transparency that made blockchains valuable in the first place), we built StealthPay—an opt-in privacy primitive for users who don’t want their on-chain activity easily trackable, while still preserving the public verifiability of transactions. StealthPay is built on ERC-5564 (Stealth Addresses) and ERC-6538 (Stealth Meta-Address Registry), using the stealth “announcer” flow to enable users to send and receive funds on-chain via one-time stealth addresses rather than their public wallet address. For this hackathon, we shipped an MVP focused on core stealth transfers. Post-hackathon, we plan to expand with features like P2P flows, ENS-based routing (we hit an ENS resolver issue on Arbitrum during implementation, which we also want to support as a first-class feature), a message/inbox experience, and other privacy-forward UX improvements.
A self-custodial payment platform that lets anyone accept crypto and fiat payments through a shareable QR code, powered by an autonomous AI agent wallet on Arbitrum.
TrainChain is a decentralized ticketing platform that transforms train travel through blockchain technology. By minting tickets as NFTs on Arbitrum, TrainChain eliminates counterfeiting, enables secur
Privacy DeFi powered by FHE. Swap, transfer, earn yield with fully encrypted balances. Prove compliance cross-chain without revealing amounts. Your trades are invisible, your credit travels
A Decentralized blockchain based zero loss lottery system.
Arbitrum-native execution layer and superapp: swap (Uniswap V3), ERC-4626 vaults, strategy NFTs, DAO automation, non-custodial agents, and an optional private RPC with MEV protection. Fully permission
Subscription infrastructure built on Arbitrum that enables autonomous recurring payments in USDC.
Execute complex cross-chain transactions with natural language. Powered by AI and optimized routing all in Arbitrum + Orbit
Tokenise, invest, borrow, and earn yield on real-world assets - verified once, executed on Arbitrum, and usable across any chain with a single source of truth.
Tilt Protocol is the definitive AI-driven management layer for tokenized real-world assets, empowering anyone to deploy or allocate to institutional-grade trading strategies natively on the Robinhood L2.
Arbitrum's Fixed Income infrastructure for tradable yield tokens, powered by automated rolling vaults and risk-free lotteries.
TrainChain is a decentralized ticketing platform that transforms train travel through blockchain technology. By minting tickets as NFTs on Arbitrum, TrainChain eliminates counterfeiting, enables secur
Most Hackathon Won
Most Project Built
Manobendra Mandal
Vivek Sahu
simp1e
Manjeet Sharma
Rick
DHRUV PANCHOLI