Prediction Market Odds Scraper (Polymarket + Kalshi)

Prediction Market Odds Scraper (Polymarket + Kalshi) pulls structured data from Polymarket Gamma API and Kalshi Trade API and returns it as a clean dataset you can export as JSON, CSV or Excel. It queries the Polymarket Gamma API and the Kalshi public trade API and merges them into one row per market with yes/no prices, volume and close date, plus a joined cross-venue spread where the same question is listed on both.

No API key, no login. Click Start and it works with the prefilled input.

What does Prediction Market Odds Scraper (Polymarket + Kalshi) do?

It queries Polymarket Gamma API and Kalshi Trade API and returns one row per record, with only the fields that matter. Runs on the Apify platform, so you get an API endpoint, scheduling, monitoring and integrations (Zapier, Make, Google Sheets, webhooks) without maintaining any infrastructure.

Why use it?

• Polymarket Gamma API and Kalshi Trade API data without the plumbing: no proxy setup, no pagination code, no scraping maintenance.
• Schedule it to monitor changes daily or weekly and trigger alerts on new records.
• Feed it straight into a spreadsheet, database, or an AI agent via the Apify API or MCP server.
• Runs in seconds and returns a typed dataset that is ready for analysis.

How to use it

1. Click Try for free / Start.
2. Leave the default input to see a sample run, or type your own values (see Input below).
3. Press Start and wait a few seconds.
4. Open the Output tab and download as JSON, CSV, Excel or HTML.

Input

Field	Type	Default	Description
query	string	""	Free-text filter on the market question. Leave blank for the highest-volume markets across both venues.
source	string	"both"	Which venues to query. Both venues are merged into one dataset. One of: 'both', 'polymarket', 'kalshi'.
minVolume	integer	0	Drop markets whose traded volume is below this. 0 keeps everything.
maxResults	integer	25	Maximum number of merged market rows to return.

Example input:

{
  "query": "",
  "source": "both",
  "minVolume": 0,
  "maxResults": 5
}

Output

One item per record. Sample:

{
  "venue": "Polymarket",
  "market_id": "0xa467b1...",
  "question": "Xi Jinping out before 2027?",
  "url": "https://polymarket.com/market/xi-jinping-out-before-2027",
  "api_url": "https://api.elections.kalshi.com/trade-api/v2/markets/KXCS2GAME-26OCT021200MEIBHE-MEI",
  "yes_bid": 0.28
}

You can download the dataset in various formats such as JSON, HTML, CSV, or Excel.

Data fields

Field	Type	Meaning
venue	string	Venue
market_id	string	Market ID
question	string	Question
url	string	Market Page
api_url	string	API Record
yes_bid	number	Yes Bid
yes_ask	number	Yes Ask
yes_price	number	Yes Price
no_price	number	No Price
spread	number	Spread
volume	number	Volume (USD)
liquidity	number	Liquidity (USD)
open_interest	number	Open Interest
close_date	string	Close Date
status	string	Status
match_key	string	Join Key
cross_venue_spread	number	Cross-Venue Spread
retrieved_at	string	Retrieved At

How much does it cost to run?

This Actor uses pay-per-event pricing: you pay per result item pushed to the dataset, and nothing for an empty run. Each run is a few seconds of compute, so typical costs are fractions of a cent per run, and the Apify free tier covers plenty of testing.

Tips and advanced options

• Raise maxResults for a bigger pull; the Actor pages through the source for you.
• Schedule it (e.g. every morning) and combine with a webhook to get only the new records.
• Add the Actor to an AI agent through the Apify MCP server for natural-language queries.

FAQ, disclaimers and support

• Is this legal? It uses publicly available data from Polymarket Gamma API and Kalshi Trade API. You are responsible for how you use the data and for complying with the source's terms.
• It returned nothing? Leave the keyword blank to get the highest-volume markets from both venues, or try a topic such as "election", "fed" or "bitcoin". Results always include both venues when available.
• Something broken? Open an issue on the Actor's Issues tab. Data sources change and get fixed quickly.
• Need a custom variant (extra fields, a different source, a scheduled report)? Get in touch through the Issues tab.