Kalshi Sports API (2026): Markets, Odds and Live Data

How are Kalshi sports markets organized?

Kalshi uses the same three levels for sports as for everything else:

Each bet type gets its own series, so one NFL game appears in KXNFLGAME, KXNFLSPREAD, KXNFLTOTAL and dozens of quarter, half and player series, all sharing the game's suffix. An NFL winner event holds two markets, one per team, while a Premier League game in KXEPLGAME holds three: one per team plus a tie.

The rules sit on each market. For the Colts and Commanders, "If the game ends in a tie, the market will resolve to $0.50 for each team", and a game not started within 48 hours of its scheduled time resolves to a fair price. The series names "the Governing League" as its settlement source. Note the shard too: NFL games trade on exchange index 0, while NBA and MLB game series sit on shard 3, which matters when you fund an account for trading.

How do you find a league's games through the API?

Start with the sport. GET /search/filters_by_sport returns 20 sport groups, from basketball and soccer to darts and chess, each with its competitions and scopes. Soccer alone listed 78 competitions on 3 October 2026. Events echo those labels in product_metadata: the Colts game carries "competition": "Pro Football" and "competition_scope": "Game".

Then go to the series. GET /series?category=Sports&tags=Football returned 584 football series, so most integrations hardcode the handful they need, such as KXNFLGAME, KXNBAGAME, KXMLBGAME, KXNHLGAME or KXEPLGAME. With a series ticker, one call returns every open game, its markets and its milestone. This runs on Node 18 or newer with no key:

const BASE = 'https://external-api.kalshi.com/trade-api/v2';

const url = `${BASE}/events?series_ticker=KXNFLGAME&status=open&with_nested_markets=true&with_milestones=true&limit=200`;
const { events, milestones } = await (await fetch(url)).json();

const american = (p) => (p >= 0.5 ? `-${Math.round((100 * p) / (1 - p))}` : `+${Math.round((100 * (1 - p)) / p)}`);

for (const event of events) {
  const milestone = milestones.find((m) => m.primary_event_tickers.includes(event.event_ticker));
  console.log(event.title, '| starts', milestone?.start_date, '| milestone', milestone?.id);
  for (const m of event.markets) {
    const ask = Number(m.yes_ask_dollars);
    if (!(ask > 0 && ask < 1)) continue;
    console.log(`  ${m.yes_sub_title}: ask ${ask.toFixed(2)} | ${(ask * 100).toFixed(0)}% | decimal ${(1 / ask).toFixed(2)} | American ${american(ask)}`);
  }
}

Milestones can also be searched directly. GET /milestones filters by type, such as football_game, and by competition, which matched the league name in our checks: competition=NFL returned NFL games, while the documented example value, Pro Football, returned none.

How do Kalshi prices convert to odds?

A Kalshi contract pays $1 if its outcome happens, so its price is an implied probability. Buying at a 35-cent ask means paying 35 cents for a $1 payout if that team wins:

Adding the asks across an event shows the margin built into the book. In the 30 open NFL games we pulled on 3 October 2026, the two teams' asks summed to between $1.00 and $1.04, with a median of $1.01. Premier League games, with three outcomes, had a median of $1.02. Those figures are before Kalshi's trading fees, which Kalshi fees explained breaks down, so a true cost comparison with a sportsbook has to add them. The wider comparison is in the best prediction market for sports betting.

How do you get live scores from the Kalshi API?

Through milestones. A milestone links a real-world occurrence to its events, and Kalshi's docs say the same milestone ID "is also the key used by the live data API". The milestone for the Colts game listed 5 primary events (winner, spread, total, team total and tie) and 70 related events in all, plus team IDs and the season and week in its details.

const BASE = 'https://external-api.kalshi.com/trade-api/v2';
const eventTicker = 'KXUEFANLGAME-26OCT02FRAITA';

const { milestones } = await (await fetch(`${BASE}/milestones?limit=1&related_event_ticker=${eventTicker}`)).json();
const milestone = milestones[0];
console.log(milestone.title, '|', milestone.type, '|', milestone.start_date);

const { live_data: live } = await (await fetch(`${BASE}/live_data/milestone/${milestone.id}`)).json();
const d = live.details;
console.log(d.status, d.time ?? d.clock, `${d.home_same_game_score ?? d.home_points}-${d.away_same_game_score ?? d.away_points}`, d.last_play?.description);

Play-by-play comes from game_stats, which Kalshi supports for pro and college football, pro and college basketball, the WNBA, soccer, pro hockey and pro baseball. It returned events such as shots and free kicks for the live soccer match, and an empty object for the NFL game before kickoff. For Pro Football, Pro Basketball and College Men's Basketball, include_player_stats=true adds player-level statistics where Kalshi has player mappings. For streaming prices rather than polling them, see the Kalshi WebSocket API guide, and for the rest of the Trade API, the Kalshi API guide.

How do you compare Kalshi sports prices with other venues?

The same game often trades on several venues, and the useful question is which one offers the best price for the exact bet you want. The Predictefy API has a sports screen for this, live since 29 September 2026. It lines up each game by bet type, period, line and selection, with one cell per venue. Each cell shows the venue's ask, plus its price after known fees. A venue without that exact line gets an empty cell rather than its nearest line, so a spread of -2.5 is never compared with -3.

Prices move quickly around kickoff and every trade carries risk, so treat any cross-venue gap as a prompt to check the live book before you act.

Frequently Asked Questions