Prediction markets

sportsdataverse.odds wraps the public market-data APIs of two prediction markets, Polymarket and Kalshi, beside The Odds API's sportsbook lines. Both are read-only and keyless: the wrappers read events, markets, prices and order books. Trading and account endpoints need signed keys and are not wrapped.

Polymarket

Polymarket serves metadata and prices from two hosts, and the function names say which:

Function	Host	Returns
`polymarket_gamma_events(limit=, closed=, tag_slug=, offset=)`	gamma (metadata)	events: groups of related markets
`polymarket_gamma_markets(limit=, closed=, order=, ascending=, offset=)`	gamma	markets, orderable by volume or liquidity
`polymarket_gamma_market(...)`	gamma	one market
`polymarket_gamma_tags(...)`	gamma	the tags (such as `sports`) that group events
`polymarket_clob_markets(...)`	clob (order book)	markets as the order book lists them
`polymarket_clob_book(...)`	clob	one outcome token's order book
`polymarket_clob_price(token_id, side)`	clob	the best price on one side of one token's book
`polymarket_clob_midpoint(...)`	clob	one token's midpoint price

The query parameters are passed as strings, as the API takes them.

from sportsdataverse.odds import polymarket_gamma_events, polymarket_gamma_markets

sports_events = polymarket_gamma_events(closed="false", limit="5", tag_slug="sports")
busiest = polymarket_gamma_markets(closed="false", limit="5", order="volume24hr", ascending="false")
print(sports_events.height, busiest.height)

Kalshi

Kalshi organizes markets as series (a market family, such as every NFL game), events (one game) and markets (one contract on that event).

Function	Returns
`kalshi_series_list(category=)`	every series in a category, such as `Sports`
`kalshi_series(...)`	one series
`kalshi_events(limit=, status=, series_ticker=, cursor=)`	events, filterable by series and status; cursor-paged
`kalshi_event(...)`	one event
`kalshi_markets(limit=, event_ticker=, cursor=)`	markets, filterable by event; cursor-paged
`kalshi_market(...)`	one market
`kalshi_orderbook(ticker, depth=)`	a market's order book, at fixed-point dollar levels
`kalshi_trades(...)`	executed trades
`kalshi_exchange_status()`	whether the exchange is open

from sportsdataverse.odds import kalshi_events, kalshi_series_list

sports_series = kalshi_series_list(category="Sports")
nfl_games = kalshi_events(limit="5", series_ticker="KXNFLGAME", status="open")
print(sports_series.height, nfl_games.height)

Conventions

Wrappers return a polars DataFrame by default; return_parsed=False gives the raw JSON and return_as_pandas=True gives pandas. parse_polymarket and parse_kalshi parse a raw payload you already have.
Errors follow the package vocabulary: a 404 raises NoDataError, a failed fetch AssetFetchError, a 400 / 422 ValueError.
A market price is what a contract trades at, and the prices of the two sides need not sum to 1 (the bid-ask spread), so they are not de-vigged probabilities. To compare them with sportsbook lines or a model, the market helpers in sportsdataverse.wexp (prob_from_american, devig_multiplicative) put both on one scale.

The Odds page lists every function with its parameters and Returns table.

Polymarket​

Kalshi​

Conventions​

Polymarket

Kalshi

Conventions