Polymarket Auto-Trader

Fully autonomous prediction market trading agent for Polymarket. Evaluates markets using LLM probability estimation, sizes positions with Kelly criterion, and executes trades via the Polymarket CLOB API from a non-US VPS.

Prerequisites

Non-US VPS — Polymarket blocks US IPs. Use DigitalOcean Amsterdam, Hetzner EU, etc.
Polygon wallet with USDC.e (bridged USDC, NOT native USDC)
MATIC for gas (~0.1 MATIC sufficient for hundreds of trades)
Anthropic API key (uses Haiku at ~$0.001/evaluation)

Setup

1. VPS Environment

SSH into your non-US VPS and run:

python3 {baseDir}/scripts/setup_vps.sh

Or manually:

apt update && apt install -y python3 python3-venv
python3 -m venv /opt/trader
/opt/trader/bin/pip install py-clob-client python-dotenv web3 requests

2. Configuration

Create /opt/trader/app/.env:

PRIVATE_KEY=<your-polygon-wallet-private-key>
LLM_API_KEY=<your-anthropic-api-key>

3. Blockchain Approvals

Before trading, approve USDC.e and CTF tokens for Polymarket contracts. Run:

python3 {baseDir}/scripts/approve_contracts.py

Required approvals (6 total):

USDC.e → CTF Exchange, Neg Risk Exchange, Neg Risk Adapter
CTF → CTF Exchange, Neg Risk Exchange, Neg Risk Adapter

4. Deploy Trading Script

cp {baseDir}/scripts/run_trade.py /opt/trader/app/
cp {baseDir}/scripts/pnl_tracker.py /opt/trader/app/

5. Cron Automation

crontab -e
# Add: */10 * * * * cd /opt/trader/app && /opt/trader/bin/python3 run_trade.py >> cron.log 2>&1

How It Works

Market Scan — Fetches active markets from Gamma API, filters by liquidity and time horizon
LLM Evaluation — Asks Claude Haiku to estimate true probability for each market
Edge Detection — Compares LLM fair value vs market price (min 5% edge threshold)
Kelly Sizing — Half-Kelly criterion with 25% max position size cap
Order Execution — Places limit orders via CLOB API with GTC (good-till-cancelled)
Dedup — Tracks all trades in trades.jsonl, skips already-traded markets
Budget Control — Tracks LLM inference costs separately from trading capital

Trading Parameters

Configurable in run_trade.py:

EDGE_THRESHOLD — Minimum edge to trade (default: 0.05 = 5%)
MIN_SHARES — Minimum order size (Polymarket requires ≥5 shares)
Bankroll allocation: 80% usable, 25% max per trade, 30% cap per single position
Market horizon: Prioritizes markets ending within 30 days

Monitoring

Check P&L anytime:

python3 /opt/trader/app/pnl_tracker.py

Check recent activity:

tail -50 /opt/trader/app/cron.log

Key Technical Details

Wallet type: EOA (signature_type=0), NOT proxy wallet
Token: USDC.e (0x2791Bca1f2de4661ED88A30C99A7a9449Aa84174), not native USDC
Neg-risk markets (elections, sports leagues) require USDC.e approval for Neg Risk Adapter (0xd91E80cF2E7be2e162c6513ceD06f1dD0dA35296)
US geoblock — All API calls must originate from non-US IP. VPN insufficient; use actual non-US VPS.

Cost

LLM inference: ~$0.001 per market evaluation (Haiku)
Typical cycle (40 evals): ~$0.04
Gas: negligible on Polygon (~$0.001 per trade)

⚠️ Security Considerations

Use a DEDICATED wallet with minimal funds. Never use your main wallet's private key. Create a fresh wallet and fund it only with what you're willing to risk.
PRIVATE_KEY is stored on disk in .env. Harden your VPS: strict file permissions (chmod 600 .env), no shared access, firewall, SSH keys only.
MAX_UINT approvals are standard in DeFi but grant broad spending rights. The approved contracts are official Polymarket contracts. Review addresses in references/contract-addresses.md before running.
Test with tiny amounts first ($5-10) before scaling up.
Monitor actively — check cron.log and run pnl_tracker.py regularly.
LLM_API_KEY billing — each cycle costs ~$0.04 (Haiku). Set billing alerts on your Anthropic account.
This is autonomous trading software. Bugs or market conditions can cause losses. Use at your own risk.

References

See references/polymarket-api.md for full CLOB API documentation
See references/contract-addresses.md for all Polygon contract addresses