Trade on real-world events with free play money. No risk, pure strategy.
PaperMarket is a paper-trading prediction market platform built on live data from Polymarket. Every account starts with $1,000 in play money to trade on politics, crypto, sports, tech, and more. Markets sync every 10 minutes — probabilities are always real.
| Live Markets | Synced from Polymarket every 10 minutes across all categories |
| Paper Trading | $1,000 free starting balance, no real money involved |
| Price Impact | Each trade shifts the market probability in real time |
| Portfolio | Track open positions, P&L, and full trade history |
| Leaderboard | Global ranking by portfolio value |
| Auth | Email/password and Google OAuth sign-in |
| Admin Panel | Resolve markets, adjust balances, sync market data |
| Layer | Technology |
|---|---|
| Frontend | React 18, TypeScript, Tailwind CSS, Vite |
| Backend | Node.js, Express, Prisma ORM |
| Database | PostgreSQL |
| Auth | JWT + Google OAuth 2.0 |
| Data | Polymarket Gamma API |
| Hosting | Vercel (web), Railway (API + database) |
Prerequisites: Docker Desktop, Node.js 18+
1. Clone the repo
git clone https://github.com/natedemoss/papermarket.git
cd papermarket2. Configure environment
cp .env.example .envFill in JWT_SECRET, GOOGLE_CLIENT_ID, GOOGLE_CLIENT_SECRET, and ADMIN_PASSWORD.
3. Start services
docker-compose build
docker-compose up -d4. Initialize the database
docker exec papermarket-api npx prisma db push \
--schema /app/apps/api/prisma/schema.prisma --accept-data-loss
docker exec papermarket-api node prisma/seed.js5. Open http://localhost:3000
| Variable | Description |
|---|---|
DATABASE_URL |
PostgreSQL connection string |
JWT_SECRET |
Secret used to sign JWT tokens |
GOOGLE_CLIENT_ID |
Google OAuth app client ID |
GOOGLE_CLIENT_SECRET |
Google OAuth app client secret |
GOOGLE_CALLBACK_URL |
Absolute URL for the OAuth callback route |
FRONTEND_URL |
Frontend origin (used for CORS and redirects) |
ADMIN_EMAIL |
Email address for the admin account |
ADMIN_PASSWORD |
Password for the admin account |
POLYMARKET_SYNC_ENABLED |
Set to true to enable automatic market sync |
When you buy YES at 34¢ you receive shares priced at that probability. If the market resolves YES, your payout is calculated from your average entry price — not the price at resolution. Early bettors are rewarded for conviction.