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
Aaditya Rawat
Skia Variants
Akan
A home for on-chain AI agents. Check what works before you pay.
PFWA is a permissionless prediction market built on Robinhood Chain, where anyone can create and trade markets around onchain assets.
Faster RNG on Robinhood Chain first, then Arbitrum: live verifiable commit-reveal randomness for games, AI agents, DeFi and real-time apps.
Explainable launch intelligence for Robinhood Chain.
Meme-World Assets (MWA) Protocol — RWA-backed token launchpad on Robinhood Chain . Creators lock tokenized stocks as collateral, issue MEME tokens with an optional 3/5/10% buyback premium, and automatically redeem collateral after the lock expires. Live on testnet with 3 deployed contracts. https://mafsc.github.io/mwa/
# Sakartvelo Exchange **A working demonstration that privatization can have a real primary market — built, deployed, and verified on Arbitrum One.** ## The problem Every large-scale privatization has failed the same way, twice. Sell state assets for cash, and only people who already have capital can buy in. Give them away as free vouchers instead — the historical "fairer" alternative — and ownership still ends up right back with whoever had capital, just a few months later, because the vouchers were tradable from day one and got sold cheap under financial pressure. Crypto has quietly reproduced the same failure at industry scale: most tokens are tradable the instant they're minted, with no real primary-market phase standing between issuance and speculation. That's not a side effect of bad token design — it's a structural gap. Traditional finance solves this with a real separation between primary allocation and secondary trading. Crypto, and historical privatization alike, usually don't have one. ## What we built A three-phase mechanism — **monetization, privatization, capitalization** — that reconstructs that missing separation, live on-chain: - **Monetization**: citizens receive an equal, one-time allocation of a currency that cannot be resold or gifted — only spent bidding on real assets. - **Privatization**: that currency competes in a proportional, multi-round auction. Unfilled bids carry forward automatically; settlement cost is mathematically bounded regardless of how large a company's total share count is. - **Capitalization**: the currency's transfer restriction lifts — permanently, for everyone — only once real, on-chain progress (a company crossing 51% sold) proves privatization is genuinely underway. Not a calendar date. Not an announcement. A verifiable fact. ## What's actually live, right now Ten companies. Real auctions. Real governance — shareholders elect term-limited governors with rotating operating keys, not standing control. A real treasury layer with sealed-bid asset sales and shareholder-voted vendor payments. All five contracts verified on Arbiscan, Sourcify, and Blockscout — anyone can read the exact logic running this, not just take our word for it. ## Why it's worth building on Arbitrum Because the interesting part of this project isn't the idea — plenty of people have written about crypto's missing primary market. The interesting part is what happens when you actually try to build it: we found and fixed a real unbounded-gas vulnerability in our own settlement logic before it could lock anyone's funds, documented it publicly, and formalized the fix as a provable bound. That's the difference between a whitepaper and a working system — and Arbitrum's low, predictable gas costs are what made iterating on that fix fast enough to actually catch it. ## What's honest about where this stands This is a fictional simulation, not a real financial product — every contract says so explicitly. We have no proof-of-personhood, no formal game-theoretic proof of the auction's incentive properties, and no professional security audit yet. We say this plainly because a project that hides its limitations is less trustworthy than one that names them — and because closing exactly these gaps is what we're building toward next.
Use staked L1 tokens as collateral to borrow USDC.
JUJING is an independent market intelligence and verification layer for tokenized stocks. Starting with Robinhood Stock Tokens on Robinhood Chain, it connects exact token identity, issuer-defined rights, onchain controls and source evidence with reference pricing, liquidity, freshness and execution context. This helps wallets, trading venues and protocols understand which instrument they are supporting and retain a reproducible verification record.
Stranded rescues tokens stuck on Arbitrum chains with zero ETH. Users sign a permit in the browser — no gas, no ETH, no bridge — the relayer pays the chain, swaps a slice for gas, and delivers the rest. One signature, tokens liquid again.
Your health and wellness Ecosystem A decentralized platform for publishing, discussion, research, collaboration, and fund allocation in health and wellness. Share what you know, build reputation, and use conviction voting to support valuable contributions and earn AROGYA.
Kipio is a decentralized vault for permanent, private ownership of personal content, built to give people lasting control over their digital memories.
Private stablecoin and tokenized-asset payments with a chosen auditor. The sender hides a payment from everyone except the reader they pick — an accountant or a regulator — who can read it but never spend or freeze it. Groth16 proofs, Rust end to end. Live on Solana and Arc mainnet; verifier and both pools deployed on Stylus on Arbitrum Sepolia and Robinhood Chain.