# Sats Faucet

A Lightning faucet for the Nostr ecosystem. Nostr users can claim a small, randomized sats payout on a cooldown schedule. The app uses **NIP-98** for authenticated requests, **LNbits** for Lightning payouts, and enforces anti-abuse rules (account age, activity score, per-pubkey and per-IP cooldowns).

## Features

- **Nostr auth** — Connect via NIP-07 (browser extension) or external signer; all claim requests are signed with NIP-98.
- **Entropy payouts** — Weighted random payout buckets (e.g. 10, 25, 50, 100 sats); quote is locked so users can’t re-roll by refreshing.
- **Anti-abuse** — Account age (e.g. 14 days), activity score, per-pubkey cooldown (e.g. 7 days), per-IP cooldown and limits, daily budget cap.
- **Transparency** — Public stats: pool balance, total paid, claim counts, recent payouts (anonymized).
- **Deposits** — Lightning address and LNURLp QR for community funding.
- **Operational controls** — `FAUCET_ENABLED`, `EMERGENCY_STOP`, minimum wallet balance guard.

## Tech stack

| Layer    | Stack |
|----------|--------|
| Frontend | React, TypeScript, Vite, Framer Motion |
| Backend  | Node.js, Express, TypeScript |
| Database | SQLite (default) or PostgreSQL |
| Payments | LNbits (Lightning) |
| Auth     | NIP-98 (Nostr HTTP Auth) |

## Prerequisites

- **Node.js** 18+
- **LNbits** instance with a wallet and admin key
- **Nostr** signer (e.g. browser extension with NIP-07) for testing claims

## Quick start

### 1. Clone and install

```bash
git clone https://git.azzamo.net/Michilis/SatsFaucet.git
cd SatsFaucet
npm install
cd backend && npm install
cd ../frontend && npm install
```

### 2. Backend configuration

```bash
cd backend
cp .env.example .env
# Edit .env: set HMAC_IP_SECRET, JWT_SECRET, LNbits keys, deposit address, etc.
```

Required at minimum:

- `HMAC_IP_SECRET` — min 32 chars (for IP hashing)
- `JWT_SECRET` — min 32 chars
- `LNBITS_BASE_URL`, `LNBITS_ADMIN_KEY`, `LNBITS_WALLET_ID`
- `DEPOSIT_LIGHTNING_ADDRESS`, `DEPOSIT_LNURLP` (for the deposit section)

See `backend/.env.example` for all options (payout weights, cooldowns, eligibility thresholds, Nostr relays).

### 3. Database

**SQLite (default):** ensure `backend/data` exists; migrations create the DB.

```bash
cd backend
npm run migrate
```

**PostgreSQL:** set `DATABASE_URL` in `.env` and run:

```bash
cd backend
npm run migrate
```

### 4. Frontend configuration

```bash
cd frontend
cp .env.example .env
# For local dev, VITE_API_URL=http://localhost:3001 is usually correct
```

### 5. Run in development

**Terminal 1 — backend:**

```bash
npm run dev:backend
# or: cd backend && npm run dev
```

**Terminal 2 — frontend:**

```bash
npm run dev:frontend
# or: cd frontend && npm run dev
```

Open the frontend URL (e.g. `http://localhost:5173`), connect Nostr, enter a Lightning address, and use “Check” then “Confirm” to claim.

## Production build

```bash
npm run build
# Builds backend (TypeScript → dist/) and frontend (Vite → frontend/dist/)
```

Run the backend (serves API; optionally serve frontend from same host or use a static host):

```bash
npm start
# or: cd backend && npm start
```

Set `TRUST_PROXY=true` when behind a reverse proxy (nginx, Caddy, etc.) so client IPs are read from `X-Forwarded-For`.

## Project structure

```
├── backend/           # Express API
│   ├── src/
│   │   ├── db/        # SQLite/Pg, migrations, schema
│   │   ├── middleware/ # NIP-98, auth, IP, rate limit
│   │   ├── routes/    # claim, auth, public, user
│   │   └── services/  # eligibility, LNbits, Nostr, quote
│   ├── .env.example
│   └── package.json
├── frontend/          # React SPA
│   ├── src/
│   │   ├── components/
│   │   ├── contexts/
│   │   ├── hooks/
│   │   ├── pages/
│   │   └── styles/
│   ├── .env.example
│   └── package.json
├── context/           # Design/overview docs
├── package.json       # Root scripts
└── README.md
```

## API overview

| Method | Endpoint          | Auth   | Description        |
|--------|-------------------|--------|--------------------|
| GET    | `/health`         | —      | Health check       |
| GET    | `/config`         | —      | Public config      |
| GET    | `/stats`          | —      | Balance, counts    |
| GET    | `/deposit`        | —      | Deposit address/QR |
| POST   | `/claim/quote`    | NIP-98 | Get payout quote   |
| POST   | `/claim/confirm`  | NIP-98 | Confirm and pay    |

Claim flow: frontend calls `POST /claim/quote` with Lightning address; if eligible, backend returns `quote_id` and `payout_sats`. Frontend then calls `POST /claim/confirm` with `quote_id` to execute the payout. Quotes are short-lived to prevent re-rolling.

## Environment variables (summary)

- **Security:** `HMAC_IP_SECRET`, `JWT_SECRET`, `NIP98_MAX_SKEW_SECONDS`, `NONCE_TTL_SECONDS`, `TRUST_PROXY`, `ALLOWED_ORIGINS`
- **Faucet:** `FAUCET_ENABLED`, `EMERGENCY_STOP`, payout weights and bucket sats, `DAILY_BUDGET_SATS`, `MIN_WALLET_BALANCE_SATS`
- **Eligibility:** `MIN_ACCOUNT_AGE_DAYS`, `MIN_ACTIVITY_SCORE`, `MIN_NOTES_COUNT`, `MIN_FOLLOWING_COUNT`, etc.
- **Cooldowns:** `COOLDOWN_DAYS`, `IP_COOLDOWN_DAYS`, `MAX_CLAIMS_PER_IP_PER_PERIOD`
- **Nostr:** `NOSTR_RELAYS`, `RELAY_TIMEOUT_MS`, `METADATA_CACHE_HOURS`
- **LNbits:** `LNBITS_BASE_URL`, `LNBITS_ADMIN_KEY`, `LNBITS_WALLET_ID`, `DEPOSIT_LIGHTNING_ADDRESS`, `DEPOSIT_LNURLP`

See `backend/.env.example` for full list and defaults.

## Security notes

- LNbits keys and secrets stay on the backend; the frontend never sees them.
- IPs are stored only as HMAC hashes (using `HMAC_IP_SECRET`).
- NIP-98 enforces method, URL, timestamp, and nonce; nonces are checked for replay.
- Use HTTPS and a reverse proxy in production; set `TRUST_PROXY` and restrict `ALLOWED_ORIGINS`.

## License

MIT (or as specified in the repository).