Data from prediction markets has become increasingly important for financial analysis, algorithmic trading strategies, and applications requiring real-time probability assessments. PolyGram and the Polymarket CLOB infrastructure both offer robust APIs that developers can leverage to build applications atop the world's most active prediction market platform.
Available APIs
Polymarket Gamma API (Market Data)
The Gamma REST API delivers event information, current pricing, and time-series market data:
- Base URL: https://gamma-api.polymarket.com
- Endpoints: /events, /markets, /positions, /activity
- Authentication: Not required to access public market information
- Rate limits: Approximately 100 calls per minute without authentication credentials
Polymarket CLOB API (Order Book & Trading)
The CLOB API grants access to live order book snapshots and facilitates order placement:
- Base URL: https://clob.polymarket.com
- Endpoints: /book, /trades, /orders, /prices/history
- WebSocket: wss://ws-subscriptions-clob.polymarket.com for live streaming data
- Authentication: ECDSA digital signatures required when submitting orders
PolyGram API
PolyGram offers its own API layer for authenticated trading functionality:
- Full technical reference available at PolyGram API Docs
- REST methods for order execution, account holdings, and market discovery
- API key-based authentication for automated trading workflows
Common Developer Use Cases
- Algorithmic trading: Systematic position adjustments triggered by quantitative signals or external data feeds
- Research dashboards: Long-term probability monitoring for political, sports, or macroeconomic outcomes
- Market aggregators: Side-by-side price comparison across multiple prediction platforms
- Embedded widgets: Display current prediction odds directly within news articles or content platforms
- Alert systems: Trigger notifications whenever market conditions cross specified boundaries
Getting Started: Fetch Market Data
Here is a straightforward Python snippet to retrieve active events in real time:
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 access via the Gamma API carries no cost, though request frequency is throttled. Order placement through the CLOB API requires a wallet with USDC funds and cryptographic signing; there are no usage charges beyond transaction costs.
- Can I paper trade with the API before risking real USDC?
- Polymarket does not offer a test or staging environment. Developers seeking risk-free practice should explore the Manifold Markets API first, then migrate to Polymarket/PolyGram CLOB once ready for production trading.
- Are there Python or JavaScript SDKs available?
- Community contributors have built third-party Python and JavaScript packages for Polymarket integration. Check GitHub repositories such as "polymarket-py" and "polymarket-js" to find actively maintained libraries.