Developers working on financial modelling, algorithmic systems, and real-time forecasting applications increasingly rely on prediction market data. PolyGram and the underlying Polymarket CLOB infrastructure provide robust APIs that grant access to the world's most active prediction market ecosystem.
Available APIs
Polymarket Gamma API (Market Data)
The Gamma REST API delivers event information, current pricing, and time-series data:
- Base URL: https://gamma-api.polymarket.com
- Endpoints: /events, /markets, /positions, /activity
- Authentication: Not required for publicly available 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 the ability to submit orders:
- Base URL: https://clob.polymarket.com
- Endpoints: /book, /trades, /orders, /prices/history
- WebSocket: wss://ws-subscriptions-clob.polymarket.com for streaming data
- Authentication: Order placement requires ECDSA-signed message authentication
PolyGram API
PolyGram offers its proprietary API layer for authenticated trading and account management:
- Full reference material available at PolyGram API Docs
- REST endpoints supporting 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 external data sources
- Research dashboards: Tracking implied probabilities over time for political or macroeconomic events
- Market aggregators: Cross-platform price comparison and arbitrage detection
- Embedded widgets: Integration of live odds displays into third-party websites and publications
- Alert systems: Automated notifications when market movements exceed specified thresholds
Getting Started: Fetch Market Data
Here's a straightforward Python script to retrieve current 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 access through the Gamma API carries no cost and operates within published rate limits. Trading via the CLOB API requires wallet funding and cryptographic signing but incurs no separate API charges.
- Can I paper trade with the API before risking real USDC?
- Polymarket lacks a testnet or sandbox mode. Developers seeking risk-free practice should explore Manifold Markets API first, then migrate to live Polymarket or PolyGram trading once ready.
- Are there Python or JavaScript SDKs available?
- Community contributors have published unofficial libraries for both languages. Check GitHub repositories named "polymarket-py" and "polymarket-js" to find actively maintained implementations.