Prediction market API vs sports odds API
Answer: a prediction-market API (for example Kalshi or Polymarket, which publish their own developer docs) gives you the price of a yes/no contract, usually between 0 and 1 (or 0 and 100 cents), set by traders on that venue. A sports odds API gives you a bookmaker's price, such as Pinnacle's decimal odds and margin. PinnFeed is a sports odds API for Pinnacle only; it does not carry prediction-market data. Many builders use both: Pinnacle's no-vig probability as a reference, the contract price as the thing they compare.
Side by side#
| Prediction-market API | Sports odds API (PinnFeed) | |
|---|---|---|
| Price unit | Contract price ≈ probability | Decimal / American odds |
| Who sets it | Traders on the venue | The bookmaker (Pinnacle) |
| Margin | Fees and spread per venue | margin field per market |
| Fair probability | The mid price is close to it | fairProb field (no-vig) |
| Data | That venue's markets | Pinnacle, 13 sports, prematch + live |
Compare a contract with Pinnacle fair probability#
Illustrative numbers, not live data:
# Pinnacle fairProb for the home win from GET /v1/odds (no-vig)
pinnacle_fair_prob = 0.463
# Ask price of a "home team wins" contract on a prediction market, in dollars
contract_ask = 0.44
edge = pinnacle_fair_prob - contract_ask
print(f"difference vs Pinnacle fair: {edge:+.3f}") # +0.023 = 2.3 points
Fees, settlement rules and the exact event wording differ by venue, so a positive difference is a hypothesis to check, not a sure thing. Background: implied probability, no-vig fair odds.
Getting the Pinnacle side#
export PINNFEED_KEY="ps_live_..."
curl -sS -H "x-api-key: $PINNFEED_KEY" "https://pinnfeed.io/v1/odds?sport=basketball&market=moneyline&main=true&limit=20"
Free (30-second delay) to prototype; real-time REST on Hobby (€29/mo); push on Builder (€99/mo). Paid plans: 3-day trial; a card is required and it is charged after day 3 unless you cancel.
Educational content for adults (18+). Prediction markets and betting are regulated differently by country; check what applies to you. Nothing here promises a profit.
Questions people ask#
Does PinnFeed have Kalshi or Polymarket data?#
No. Use each venue's own API for contract prices.
Why use Pinnacle as the reference?#
Pinnacle is widely used as a sharp reference price. Its fairProb gives you a margin-free probability to line up against a contract price.
Can I match events automatically?#
Only by your own mapping (teams, start time). See event ID mapping.