Forecasting applications, quantitative research, and real-time trading strategies increasingly rely on prediction market data streams. The largest prediction market ecosystem—powered by PolyGram and the Polymarket CLOB infrastructure—offers comprehensive APIs that enable developers to integrate live market signals into their own applications.
Available APIs
Polymarket Gamma API (Market Data)
Market metadata, current pricing, and historical snapshots are accessible through the Gamma REST API:
- Base URL: https://gamma-api.polymarket.com
- Endpoints: /events, /markets, /positions, /activity
- Authentication: Not required to retrieve public market information
- Rate limits: Approximately 100 requests per minute when using unauthenticated access
Polymarket CLOB API (Order Book & Trading)
Real-time order book snapshots and order placement capabilities are delivered via the CLOB API:
- Base URL: https://clob.polymarket.com
- Endpoints: /book, /trades, /orders, /prices/history
- WebSocket: wss://ws-subscriptions-clob.polymarket.com enables live streaming of market events
- Authentication: Order placement requires ECDSA-signed cryptographic verification
PolyGram API
PolyGram offers its own dedicated API layer for authenticated trading workflows:
- Comprehensive reference materials available at PolyGram API Docs
- REST-based operations for order execution, account holdings, and market discovery
- API key-based authentication enables headless and programmatic workflows
Common Developer Use Cases
- Algorithmic trading: Systematic position sizing and rebalancing triggered by external data sources
- Research dashboards: Time-series probability analysis for geopolitical, election, and macroeconomic events
- Market aggregators: Cross-platform price discovery and arbitrage identification across prediction venues
- Embedded widgets: Integrate live odds displays into editorial platforms, financial news sites, or information portals
- Alert systems: Automated notifications when market conditions breach specified parameters
Getting Started: Fetch Market Data
Here is a straightforward Python snippet to retrieve active market events:
import requests
response = requests.get(
"https://gamma-api.polymarket.com/events",
params={"limit": 10, "active": "true", "order": "volume24hr"}
)
events = response.json()
for event in events:
print(event["title"], event["volume"])FAQ
- Is the Polymarket API free to use?
- Market data endpoints (Gamma API) carry no cost and operate under rate-limit constraints. Trading operations via the CLOB API require a wallet holding USDC and signed transactions but do not incur API-specific charges.
- Can I paper trade with the API before risking real USDC?
- Polymarket does not provide a testnet or staging environment. Developers should explore Manifold Markets' API for simulated trading, then migrate to Polymarket/PolyGram for production crypto settlement workflows.
- Are there Python or JavaScript SDKs available?
- Community contributors have published unofficial libraries for both Python and JavaScript. GitHub repositories named "polymarket-py" and "polymarket-js" represent the most actively maintained third-party implementations.