# RAIN Risk Markets

**A permissionless risk-markets protocol on Arbitrum One.** Anyone can sell risk by
depositing into an ERC-4626 vault (earning the house spread), and anyone can buy risk
by taking positions on listed two-outcome markets — settled trustlessly by Chainlink
VRF v2.5. The core design invariant is **value conservation**: every position's
worst-case payout is fully reserved against vault TVL at placement time, so the vault
can never owe more than it holds.

## Live

- 🌐 Site: https://rainsandbox.xyz
- 🚀 dApp (DEMO play-money + LIVE USDC): https://rainsandbox.xyz/app/
- 🎡 Roulette (demo): https://rainsandbox.xyz/app/roulette.html
- 📊 Protocol simulator: https://rainsandbox.xyz/riskmarkets/
- 📄 Whitepaper: [WHITEPAPER-v0.9.md](WHITEPAPER-v0.9.md)

## Contracts — Arbitrum One (42161)

### LIVE stack (USDC)

| Contract | Address |
|---|---|
| MarketRegistry | `0x076149f4293549b78C909315B3465805922fDf70` |
| RiskVault (ERC-4626, asset = USDC) | `0x9eDCB60620Ad062C4EbA71d5B457eA08fc1EadE8` |
| FeeSplitter | `0x0dd5cE18cFdc7345f0caA212B94747c052EfA947` |
| VRFAdapter | `0x2afFca69f8aa481afDCE3c15669225246dC2008B` |
| RiskEngine | `0x16700BA3141Dd73ea0139B1e6663B6b40268d99d` |

### DEMO stack (RUSD play money)

| Contract | Address |
|---|---|
| RUSD (RISK Dollar, 6 dec) | `0x260c7019E760763988843Bc5b873d749b5937469` |
| MarketRegistry (demo) | `0xADf3B1270961231ff925C8885843c597502A3d44` |
| RiskVault (demo, asset = RUSD) | `0xEcF918c851d9259DDaEc48d51D8363CBaDe3A18F` |
| FeeSplitter (demo) | `0x46F8478aeDbE189ffa85CE06BFF767c57b7d403c` |
| VRFAdapter (demo) | `0x17fb4Fc8778aF721D28846F64A391F7D7374d47f` |
| RiskEngine (demo) | `0x4fd901d0f18d738142F86A82AC1895D4B0C6EBa5` |

## Architecture

```
                 deposit / withdraw (ERC-4626)
   LPs  ────────────────────────────────────────►  RiskVault
                                                     ▲    │ reserve / release
                                                     │    ▼
   Traders ──placePosition──►  RiskEngine  ◄──────  MarketRegistry
                                  │  ▲                (markets: prob, payoutX,
                    requestWords  │  │ fulfill         EV ≤ 98.75% floor)
                                  ▼  │
                              VRFAdapter ◄────────► Chainlink VRF v2.5
                                  │
                        fees ─────▼
                              FeeSplitter (protocol / brand split)
```

- **RiskVault** — ERC-4626 vault; LPs sell risk; TVL cap, high-water mark,
  recovery gate, 48h withdrawal delay.
- **MarketRegistry** — permissionless listing of two-outcome markets with a
  spread floor (EV ≤ 98.75%).
- **RiskEngine** — places positions, reserves worst-case payouts against the
  vault (value-conservation invariant), settles on VRF callback, timeout voids.
- **VRFAdapter** — Chainlink VRF v2.5 consumer.
- **FeeSplitter** — splits spread revenue.

## Build & Test

Requires [Foundry](https://book.getfoundry.sh/).

```bash
cd protocol
forge install OpenZeppelin/openzeppelin-contracts
forge install smartcontractkit/chainlink-brownie-contracts
forge install foundry-rs/forge-std
forge build
forge test -vv        # unit + fuzz tests, incl. value-conservation invariant
```

Note: `lib/` is not included in this release — install dependencies with
`forge install` as above (remappings are in `foundry.toml`).

## Directory Layout

```
protocol/    Foundry project — src/ (6 contracts), script/ (deploy), test/
app/         Static dApp (ethers v6, no build step) — index.html, app.js,
             roulette.html, roulette.js, abis.js, style.css
simulator/   Single-file protocol simulator (as deployed at /riskmarkets/)
WHITEPAPER-v0.9.md
DEPLOYMENT.md   Mainnet deployment log (scrubbed)
```

## Contributing

See [CONTRIBUTING.md](CONTRIBUTING.md).

## License

MIT — see [LICENSE](LICENSE).