3 langkah, kamu punya aset. Urunan bareng teman beli bagian rumah kos, terima sewanya, dan unit dapat dijual ke investor terverifikasi (can be sold to verified investors).
Built for the Ethereum Jakarta Hackathon 2026 (theme: Real-World Assets) on Robinhood Chain Testnet, an Ethereum L2.
| Author | Muhamad Septian Pamungkas (solo builder) |
| Live app | https://ursset.vercel.app |
| Demo video | https://youtu.be/lO4ZWxfpNtI |
| Pitch video | https://youtu.be/jGRaYYAL9Hg |
| Chain | Robinhood Chain Testnet (chain ID 46630) |
| Explorer | https://explorer.testnet.chain.robinhood.com |
This is a hackathon demo on a test network. Property data is illustrative, "Rupiah" is a test token (tIDR), and nothing here is an investment offer or promises any return.
- Property needs large capital, so most young Indonesians are locked out.
- On fractional platforms, money is often locked up and investors must trust the operator's rent reports.
- Crypto-based products ask normal people to understand wallets, gas and seed phrases.
A fractional rental-property app whose UX hides the blockchain but keeps every important fact verifiable onchain.
- Masuk. Sign in with email or Google. A wallet is created silently (Privy embedded wallet), no seed phrase, no gas.
- Isi saldo. Top up Rupiah (QRIS is simulated; the balance is test Rupiah). A light identity check marks the wallet as verified.
- Urunan. Pick an amount, tap once. You now own units of a rental property.
On top of that:
- Urunan Room. Create a room with a target, share one link, and friends join with their own amounts. Everyone receives units in their own wallet; nobody holds anyone else's money.
- Public rent history. Every rent deposit and its pro rata split is an onchain event anyone can check ("Lihat bukti di blockchain" in Indonesian, "View proof on blockchain" in English, on every transaction). Rent deposits and their split can be checked; whether the rooms are really rented still depends on the operator/SPV and on audits, which is a risk we acknowledge.
- Resale. Units can be sold to other verified investors at a price you set; liquidity is not guaranteed.
- List any property in one transaction. The operator form (
/operator) takes a name, city, rooms, value, description and photos, thenPropertyFactorydeploys that property's token, sale, rent distributor and marketplace and wires them together. Photos go to Vercel Blob (or paste image links). - Two languages. The whole UI switches between Indonesian and English from the header (ID | EN).
- Allow-list enforcement in code. (Not a claim of regulatory compliance.) Units can only move between wallets verified in the
KYCRegistry. A transfer to an unverified wallet is rejected by the smart contract, not by the app.
Ownership, rent payouts and resale between investors happen on a public ledger the operator does not control, so investors can verify for themselves without trusting a database, while KYC rules are enforced directly by the contract. The chain proves what was deposited and how it was split, not that the rooms were really rented.
Investor (Next.js app, Privy login) Operator (server, Next.js API routes)
buy / sell / claim / create room gas drip, KYC flag, mint tIDR, deposit rent
\ /
v v
+--------------------------------------------------------+
| Robinhood Chain Testnet (46630) |
| |
| PrimarySale RentDistributor Marketplace |
| \ | / |
| +---------> PropertyToken <--+----> KYCRegistry |
| (units) (checked on |
| MockIDR (tIDR) every transfer) |
+--------------------------------------------------------+
"7 contracts" means 7 contract types: each listed property creates 4 contracts (PropertyToken, PrimarySale, RentDistributor, Marketplace) through the factory, next to the 3 shared ones.
| Contract | Role |
|---|---|
PropertyFactory |
Lists a property in one transaction: deploys and wires PropertyToken, RentDistributor, PrimarySale and Marketplace, verifies the sale contract and mints the unit inventory, then hands ownership to the operator. Only the operator can call it. |
KYCRegistry |
Allow-list of verified wallets. Only an address and a boolean are stored, never personal data. |
MockIDR |
Test Rupiah (tIDR, zero decimals). Simulates a balance topped up through a licensed payment provider. |
PropertyToken |
ERC-20 units of one property (300,000 units). _update requires both sides to be verified. Stores the legal-document hash. |
RentDistributor |
Splits rent deposits pro rata with an accumulator, so cost does not grow with the number of holders. Unsold inventory earns no rent. |
PrimarySale |
Fixed-price primary sale (Rp10,000 per unit) and Urunan Rooms (target, progress, contributors). |
Marketplace |
Non-custodial fixed-price resale. Units stay in the seller's wallet and keep earning rent until filled. |
The shared contracts (KYCRegistry, MockIDR, PropertyFactory) are written to packages/nextjs/lib/generated/ursset.ts after each deploy. Each listed property's own contract addresses come from PropertyFactory.properties(id). Current deployment:
| Contract | Address (Robinhood Chain Testnet, 46630) |
|---|---|
| KYCRegistry | 0x5146ffc33d970cea588d96ec6b66d7fed74ebc49 |
| MockIDR (tIDR) | 0x286db2aef28ddb1928d16075f972edb477851934 |
| PropertyFactory | 0x17130f4e84634f6f6c1bcd0bb3c606b4325b676a |
| Kos Melati Depok: PropertyToken | 0x19C7F8102e9bD4393feEF19e4d372BE378B42e2e |
| Kos Melati Depok: PrimarySale | 0xD349471fd85CDab73592690Ea6323a076add801e |
| Kos Melati Depok: RentDistributor | 0x7797583A83f46DA9A5d57985bd6B4a516a1cF26A |
| Kos Melati Depok: Marketplace | 0xEef387528409F62f96D55d1ac65ea7C5a4F69602 |
| Kos Dago Asri Bandung: PropertyToken | 0x0f46a9ca04EC32A1fFc644C1B396Bfe0CFb5b41A |
| Kos Dago Asri Bandung: PrimarySale | 0xb8916A0cB79012c7C92Cc8130B084D3B9bCA35d1 |
| Kos Dago Asri Bandung: RentDistributor | 0x90a0B0782056C0C6f2Bd4b29aC884f468DDa992C |
| Kos Dago Asri Bandung: Marketplace | 0x8f092eD60713F081CC0CA883e0dE6bEA3e42B5D6 |
Requirements: Node 20+, Yarn, Foundry.
yarn install
cd packages/foundry && forge test # 45 tests
# Frontend
cp packages/nextjs/.env.example packages/nextjs/.env.local # then fill in the values
yarn start # http://localhost:3000Deploy contracts to Robinhood Chain Testnet (needs testnet ETH from the faucet):
cd packages/foundry
cp .env.example .env # add DEPLOYER_PRIVATE_KEY (testnet-only wallet)
export METADATA_BASE=https://YOUR-APP.vercel.app # where /properties/*.json for the two seed properties is hosted
forge script script/Deploy.s.sol --rpc-url robinhood --private-key "$DEPLOYER_PRIVATE_KEY" --broadcast --ffi
node scripts-js/exportUrsset.mjs 46630 # writes ABIs and addresses for the frontendSmoke test the deployed contracts with two throwaway investors (onboarding, Urunan Room, rent, resale, KYC rejection):
cd packages/nextjs && node scripts/e2e.mjsOptional photo upload needs a Vercel Blob store: in the Vercel dashboard open Storage, create a Blob store and connect it to the project (this sets BLOB_READ_WRITE_TOKEN). Without it the operator form still works with pasted image links.
The domain of Robinhood Chain's RPC is blocked by some Indonesian ISPs. If calls fail with a TLS error, switch your DNS to 1.1.1.1, or set NEXT_PUBLIC_RPC_URL to this app's own /api/rpc proxy.
packages/foundry/test/URSSET.t.sol covers:
- Factory: wiring, independent properties, operator-only listing, rent deposits after creation, role checks.
- KYC: unverified buyers and receivers are rejected, revoked wallets cannot send.
- Sale: payment and delivery, sold-out limit, Urunan Room progress and per-person ownership.
- Rent: pro rata split, unsold inventory earns nothing, late buyers get no past rent, rent follows units after a transfer, only the operator can deposit.
- Marketplace: sale, unverified buyer rejected, seller keeps earning rent while listed, only the seller can cancel.
Everything in packages/foundry/contracts, packages/foundry/test, packages/foundry/script/Deploy.s.sol, packages/foundry/scripts-js/exportUrsset.mjs, and packages/nextjs (pages, components, API routes, hooks) was written during the hackathon.
Third-party code and services, with attribution:
- Scaffold-ETH 2 (project scaffold, Foundry setup and
generateTsAbistooling). Its example UI was removed. - OpenZeppelin Contracts 5.x (ERC-20, Ownable, SafeERC20).
- Foundry and forge-std.
- Privy (email and Google login, embedded wallets, server-side token verification).
- Next.js, React, wagmi, viem, TanStack Query, Tailwind CSS, qrcode.react.
- Testnet only. Rupiah is simulated with a test token; the QRIS top-up is a simulation. The identity check is a demo flag and no personal data is collected.
- Test token shortcut.
MockIDRskips the approve step for the sale, marketplace and distributor so a purchase is one transaction. A production setup would use a licensed payment provider and normal approvals or permits. - Operator is trusted. One server key verifies wallets, mints test Rupiah and deposits rent. In production, KYC comes from a licensed provider and rent from the SPV's bank account via a licensed payment service provider.
- Legal structure. In production the property is held by an SPV (PT); investors hold economic rights represented by the token, not the land certificate. The hash of legal documents is stored in the token. Tokenized property rights are likely regulated by OJK in Indonesia; the plan is the OJK Regulatory Sandbox route, as earlier property tokenization players took, with Rupiah in and out through a licensed payment provider.
- Contracts were redeployed. An earlier deployment was replaced after a mistyped demo rent deposit; the history is in
docs/DEPLOYMENTS.md. - Rent, tax and law (not settled). Rent is likely subject to income tax and/or VAT; the legal standing of rent rights held in an SPV needs a clear legal structure; crypto-asset oversight in Indonesia has moved to OJK, so the rules may change. We have no legal or tax advice yet.
- Next: pilot with one real boarding house, sandbox application, licensed payment partner, secondary-market fees, multiple properties.
Listing fee from the property owner: about 3% of funds raised is an unvalidated assumption and is not implemented in the contracts. Illustration only: Rp500 million raised would mean Rp15 million per listing, paid once. Owners need capital for renovation or new rooms without bank collateral. Investors pay no platform fee. Recurring revenue (secondary-market fees, rent management) is a later phase.
This is a review by an AI agent, not a third-party audit and not a human audit firm. The agent reviewed all 7 contract types (access control, reentrancy and ordering, rent rounding, KYC revocation, marketplace staleness) and found no way for a non-operator user to steal funds or units, take rent twice, or move units to an unverified wallet. Property-based tests pin the invariants: rent owed plus claimed never exceeds deposited, balances sum to supply, units only sit in verified wallets or the sale contract, and a stranger can never receive units. 45 Foundry tests pass.
Honest limits of this testnet demo (details and proposed fixes in docs/SECURITY.md):
- A single operator key is a single point of failure: it can verify or un-verify wallets, mint test Rupiah, and, through the test-token shortcut in
MockIDR, move test tIDR without approval. This exists only becauseMockIDRis a test token. - Un-verifying a holder freezes their units; rent they already earned stays claimable. A production design needs a recovery policy.
- Rent is split with a snapshot at deposit time, so a wallet can buy units right before a deposit and sell right after. We acknowledge this and have no contract-level mitigation (the operator can only reduce it by depositing privately), and rounding can dust fractions of a rupiah.
- KYC is a boolean flag set by the operator; no real identity check happens in the demo.
MIT, see LICENCE.