Prediction markets / Mappings
Consensus odds next to prediction-market prices.
HalfPoint's /mappings gives each fixture's ids at trading venues, with the instruments you trade or stream each outcome by, for example Kalshi market tickers and Polymarket CLOB token ids. Our consensus on /odds, a de-vigged, market-implied probability per outcome, carries the same fixture id. Join the two to compare a venue's price with our consensus, outcome by outcome.
01 / Mappings
Where each game trades.
Each venue entry has its event id and, under markets, the instrument of each outcome. Which keys a fixture has varies and grows over time, so ignore keys you don't know. A mapping says where a game trades, not what the consensus is built from.
curl -H "X-Api-Key: $KEY" "https://fixtures.halfpoint.tech/mappings?league=nfl&date=2026-10-29"{
"league": {"id": "nfl", "name": "NFL", "sport": "Football"},
"fixtures": [
{
"id": "nfl-261029-car-gb",
"mappings": {
"ESPN": {"id": "401873023"},
"polymarket": {
"id": "1158894",
"slug": "nfl-car-gb-2026-10-30",
"markets": {"moneyline": {"away": "44088474…", "home": "14454103…"}}
},
...
}
}
]
}02 / Consensus
Join on the fixture id.
/odds lists the games starting within the next 24 hours and those being played, each outcome's probability summing to 1. Its id is the fixture id of /mappings, so the answers join on it.
curl -H "X-Api-Key: $KEY" "https://odds.halfpoint.tech/odds?league=nfl"| Market | Leagues | Outcomes |
|---|---|---|
moneyline | MLB, NBA, NFL, college football, NHL | away, home: the game winner incl. overtime or extra innings |
moneyline_3way | Premier League, Bundesliga, LaLiga, Champions League | away, home, draw: each the Yes side of the venue's market |
Mappings follow reschedules until a game starts; then they stay. Venues list games days to weeks ahead, so a fixture gets its venues as they appear.
03 / Plan
Mappings on every plan.
Consensus (USD 49 a month, 7-day trial) includes mappings, fixtures, live scores, grades and the consensus over REST. Realtime streams the consensus; Risk adds the bet-stop and the consensus range.
04 / Docs
Read the documentation.
Questions
Which API gives consensus odds for Kalshi and Polymarket sports markets?
HalfPoint. /mappings gives each fixture's event and instrument ids at trading venues, for example Kalshi market tickers and Polymarket CLOB token ids, and /odds gives a de-vigged, market-implied consensus probability per outcome under the same fixture id. Join the two to compare a venue's price with our consensus. A mapping says where a game trades, not what the consensus is built from.
What is the best sports odds API for prediction markets?
That depends on what you need. HalfPoint delivers one de-vigged, market-implied consensus probability per outcome, each fixture's prediction-market instrument ids in /mappings, and on the Risk plan a bet-stop and a consensus range around the price. If you need each sportsbook's lines or props, an odds API that relays bookmaker odds fits better.
Which ids does /mappings return for a prediction market?
Per venue, the event id and, under markets, the instrument of each outcome: for Polymarket the Gamma event id, the event slug and CLOB token ids; for Kalshi the event ticker and market tickers. Which keys a fixture has varies and grows over time, so ignore keys you don't know.
Which markets are mapped?
The winner market: moneyline (away, home) for MLB, NBA, NFL, college football and NHL, and moneyline_3way (away, home, draw, each the Yes side of the venue's market) for the Premier League, the Bundesliga, LaLiga and the Champions League.
When does a fixture get its mappings?
Venues list games days to weeks ahead, so a fixture gets its venues as they appear. Mappings follow reschedules until a game starts; then they stay.
Which plan includes /mappings?
Every plan. Consensus (USD 49 a month) includes mappings, fixtures, live scores, grades and the consensus over REST. Realtime streams the consensus; Risk adds the bet-stop and the consensus range.
Consensus and Risk for the sharp side of the market.