Polymarket Markets Scraper

Get clean, structured data about Polymarket prediction markets: questions, live outcome prices, trading volume, liquidity, spreads, end dates and category tags. The actor reads Polymarket's public Gamma API — no login, no cookies, no proxies needed.

Who is this for?

• Researchers studying forecasting accuracy and market-implied probabilities
• Traders screening for high-volume or mispriced markets
• Journalists tracking what odds markets assign to elections, geopolitics, sports and crypto events
• Data teams feeding dashboards or alerting pipelines with market probabilities

Features

• Free-text search across markets (same search Polymarket's site uses)
• Filter by category tag (politics, crypto, sports, ...), active/closed status and minimum volume
• Sort by volume, liquidity, end date or creation date
• Parsed outcome prices (probabilities) instead of Polymarket's raw JSON-string encoding
• Automatic pagination, retries with exponential backoff, and partial results if the API hiccups mid-run

Input

{
    "searchQuery": "bitcoin",
    "active": true,
    "closed": false,
    "tagSlug": "crypto",
    "minVolume": 10000,
    "sortBy": "volume",
    "maxItems": 100
}

Field	Type	Default	Notes
searchQuery	string	–	Free-text search. When set, tagSlug is ignored.
active	boolean	true	Only currently tradeable markets.
closed	boolean	false	Include resolved markets (set active: false too for purely historical data).
tagSlug	string	–	Category slug from polymarket.com URLs, e.g. politics.
minVolume	integer	0	Skip markets under this all-time USD volume.
sortBy	enum	volume	volume, liquidity, endDate (soonest first) or newest.
maxItems	integer	100	Hard cap 5000.

Output

One dataset item per market:

{
    "id": "512263",
    "question": "US x Iran permanent peace deal by May 31, 2026?",
    "slug": "us-x-iran-permanent-peace-deal-by-may-31-2026",
    "url": "https://polymarket.com/event/us-x-iran-permanent-peace-deal-by-may-31-2026",
    "outcomes": [
        { "outcome": "Yes", "price": 0.045 },
        { "outcome": "No", "price": 0.955 }
    ],
    "volumeUsd": 82819486.16,
    "liquidityUsd": 947777.08,
    "endDate": "2026-05-31T12:00:00Z",
    "active": true,
    "closed": false,
    "tags": ["politics", "geopolitics"],
    "spread": 0.01,
    "dailyVolume": 152340.55,
    "bestBid": 0.04,
    "bestAsk": 0.05,
    "eventTitle": "US x Iran permanent peace deal by May 31, 2026?",
    "eventSlug": "us-x-iran-permanent-peace-deal-by-may-31-2026",
    "timestamp": "2026-07-24T12:00:00.000Z"
}

outcomes[].price is the current market price of that outcome share in USD, which doubles as the market-implied probability (0–1).

Pricing

The actor charges per market returned (result-item event), so a run of 100 markets costs 100 events. You only pay for data you actually receive.

Honest limitations

• Prices are snapshots, not a stream. Run the actor on a schedule if you need time series.
• Data comes from the Gamma API, which can lag the trading engine by a few seconds.
• tags are only available when the market's parent event exposes them; some markets have an empty tag list.
• Free-text search returns what Polymarket's own search ranks as relevant (roughly the top ~50 events), not an exhaustive keyword scan of every market.
• The Gamma API is public but unversioned; Polymarket may change fields without notice. The actor validates every item and skips malformed ones rather than failing the run.

Usage tips

• Historical/resolved markets: { "active": false, "closed": true, "sortBy": "volume" }
• Markets resolving soon: { "sortBy": "endDate", "minVolume": 50000 }
• Everything Polymarket says about an election: { "searchQuery": "presidential election" }