Questions · Polymarket
Is there a Polymarket API? Yes — here's the practical guide
Short answer: yes, Polymarket exposes public APIs and you don't need an API key to read them. Longer answer: the data is spread across three services, and stitching it into usable rows is where the work is.
The raw endpoints
- Gamma API — market metadata: questions, slugs, categories, volumes, outcome prices as strings-inside-JSON.
- CLOB API — order books, bid/ask, spreads and price history per outcome token (you address markets by token ID, not by name).
- Data API — the public trade tape: individual trades with wallets, sides, sizes and timestamps.
All public, all free, all real — and all shaped for Polymarket's own frontend rather than your analysis. To answer "what are the odds on X and how did they move", you join Gamma metadata to CLOB token IDs, handle pagination and string-encoded arrays, and merge price series to market rows.
The one-call version
The Polymarket Odds Snapshot actor does that stitching and returns flat rows — question, prices per outcome, bid/ask, spread, volume, liquidity, end date, optional price history — selected by category, volume floor or slug list, at $0.001 per market (a 100-market snapshot ≈ $0.12). For the tape, the Whale Trades Tracker returns large trades with wallet aggregation; for trader records, the Wallet P&L Analyzer reconstructs any wallet's realized P&L.
Questions
Frequently asked
Do I need an API key for Polymarket data?
No — Polymarket's read endpoints are public. The actors need only an Apify account; no Polymarket account, wallet or blockchain setup.
Can I get Polymarket price history?
Yes — the CLOB exposes recent per-token price series, and the Odds Snapshot actor's history mode attaches that series to each market row ($0.005 per market with history).
Is Polymarket data legal to use?
The trade tape and market data are public by design — prices and trades on a public exchange. The actors read only these public endpoints.
Polymarket Odds Snapshot
A 100-market snapshot costs about $0.12; a 25-market watchlist with full price history about $0.17.