Open House Archive
Welcome to the Open House Archive - your central repository for accessing all previous Open House buildathons and projects.
Welcome to the Open House Archive - your central repository for accessing all previous Open House buildathons and projects.
Most Hackathon Won
Most Project Built
Manobendra Mandal
Vivek Sahu
simp1e
Akan
Skia Variants
Hafiidh Luqmanul Hakim
Palpitada is live on Arbitrum since Dec/25 with a dual-engine prediction market — LMSR for cold-start liquidity + on-chain CLOB for liquid markets. Nobody else combines both. Add gasless EIP-712 transactions, native USDC settlement, $1 minimum bets, and a mobile-first PWA, and you get prediction markets that actually work on a phone — for everyone, everywhere. We're an Arbitrum Foundation grant recipient ($49k, Nethermind audit in progress). Beta in production, organic users, real volume. The hard tech is shipped: smart contracts, subgraph, EIP-712 gasless transactions, embedded wallets with social login, USDC settlement, PIX rails in Brazil — all built solo, all live on Arbitrum mainnet. Buildathon = scale what's already shipped.
Bivium turns your wallet into its own lending venue. You set the rate, you pick the collateral, and people borrow from you not from an anonymous pool. Built on EIP-7702, every wallet is a resting limit order. When risk shows up, it stays with the lender who signed it.
Delta-neutral vault capturing perp funding spreads on Nado and Extended. Exchange points distributed weekly to depositors. ~31% APY on USDC. https://atoma.fi/
Bastion is live security coordination infrastructure for Arbitrum and Robinhood Chain escrow-backed bug bounties with onchain-verifiable payouts, so researchers know the money exists before they hunt and projects can prove every payout. USDC held in escrow, reports hashed onchain, a six-stage disclosure lifecycle with 90-day windows, and a Launch Readiness Program that gives pre-mainnet projects a verifiable security history before they ship. New chains launch with zero security infrastructure; Bastion is built to be there from day one. Live at bastion.report.
Atrium is a 3-tranche principal-first primitive for on-chain RWA and yield-bearing stablecoins, targeting institutional LPs.
KwesPay is building the payment rails for the programmable economy, starting with Africa. Built with Arbitrum and designed for multichain commerce, KwesPay enables merchants to accept stablecoins and volatile crypto assets through seamless embedded checkout infrastructure with fast settlement, onchain verification, and borderless payments built for modern commerce. We’re turning crypto from speculation into real world payment infrastructure.
The coordination layer for Europe's official BAYC chapter. BAYC holders across Europe can't find, trust or help each other. We fix that: wallet-verified profiles, city map, noticeboard and AI-powered matching. Soulbound badges reward real contribution. Scales to any membership organisation globally.
An AI multiplayer game builder and creator economy.
Demo Blockchain + Cryptographie + Contrat Intelligent + Résilience éternelle + FastAPI backend pour Hackathons, développée en Python pour l’API et la cryptographie, Solidity pour les smart contracts,
ExecutionHub is a non-custodial DeFi hub that lets users connect their own wallet, create automated limit orders, swap tokens, and bridge assets across compatible networks. The goal is to keep DeFi user-controlled while improving execution clarity, route review, automation and cross-chain UX. For this Buildathon, I want to expand and refine ExecutionHub on Arbitrum, focusing on safer on-chain operations without custody.
Z0tz is a gasless confidential stablecoin wallet designed to make privacy the default user experience in Web3. Built with Fhenix CoFHE, ERC-4337 account abstraction, P-256 passkeys, stealth addresses, and a custom paymaster, Z0tz lets users hold, send, bridge, and use stablecoins without seed phrases, without ETH for gas, and without exposing their wallet identity or balances on-chain. Instead of treating privacy as an optional feature, Z0tz makes it architectural: encrypted balances, pseudonymous accounting, stealth-routed payments, and confidential DeFi flows are built directly into the wallet. Through Tezcatli vaults, users can access shielded Aave V3 yield, while the upcoming dApps tab extends the same privacy model to WalletConnect-enabled protocols such as Aave, Uniswap, and other permissionless applications. Z0tz is not just a private wallet. It is a privacy wallet layer for stablecoins, DeFi, and future Fhenix dApps. Fhenix encrypts computation. Z0tz encrypts the user. 🦇
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