Odds API for Arbitrage Betting

An arbitrage betting API that returns every Australian book's price per market through byBookmaker, so you can scan every bookmaker and alt line for arbs and middles.

An arbitrage betting API is a data feed that returns every bookmaker's price for the same market in one response, so your software can scan for outcomes whose combined implied probability falls below 100%. That sub-100% gap is the locked-in margin. SockOdds is built for it: 21 Australian books, the Betfair Exchange and the prediction markets priced side by side under a single byBookmaker object, including the alternate lines where most arbs and middles hide.

Why use SockOdds for arbitrage

• One call returns every book's price. The byBookmaker object stacks 21 Australian sportsbooks, the exchange and the prediction markets against the same market, so a single request hands you the full price ladder.
• Sharp anchors ship in the feed. Pinnacle and the Betfair Exchange sit next to Sportsbet, TAB and Ladbrokes; the sharp prices anchor fair value, the softer books are where the gap opens.
• Alt lines are first-class. Most real arbs, and nearly every middle, live on alternate lines. Ask with includeAltLines=true and they come through the same structure.
• A fair line is already computed. Each market ships fairOdds (no-vig) and bookOdds (with vig) on Base and above, so you can rank true edge and discard stale prices.
• Deeplinks and status are bundled. links.bookmakers and links.betslip get the user to the bet; available and info.stale stop you acting on a dead price.

How an arbitrage finder works with our data

With arbitrage the maths is the easy part. The hard part is having every book's price for the same market, at the same instant, in one place. Pull the event once and the comparison is already assembled.

Pull every book in one call

Request an event with odds and each market arrives collated: inside its byBookmaker map every book's entry carries odds, decimal, the line in spread or overUnder, and an available flag.

Compute total implied probability under 100%

For each outcome take the best available decimal across books. Sum the inverses; a normal market sums above 1.0 because of the vig, and an arbitrage exists only when the best cross-book prices push it below. Your margin is (1 / sum) − 1, and stakes split proportional to (1 / decimal) / sum. Over at 2.05 at one book and under at 2.00 at another imply 48.78% + 50.00% = 98.78%: a 1.23% margin.

Where alt lines create middles, and why speed matters

A middle is the upside case: book A posts Home −5.5, book B posts Away +6.5, and a 6-point win cashes both. Those gaps only show when you see alternate lines across books at once. The catch is decay: prices refresh every ~2 minutes, so verify on the book (the event carries the link) before staking.

Example request

curl "https://api.sockodds.com/v2/events/?leagueID=AFL&oddsAvailable=true&includeAltLines=false" \
  -H "x-api-key: YOUR_API_KEY"

The same market comes back priced by every book under byBookmaker, with bookOdds already computed (trimmed):

{
  "eventID": "afl_2026-09-03_fremantle_vs_hawthorn",
  "leagueID": "AFL",
  "odds": {
    "points-all-game-eo-odd": {
      "oddID": "points-all-game-eo-odd",
      "opposingOddID": "points-all-game-eo-even",
      "marketName": "Odd/Even Total Points",
      "statID": "points",
      "statEntityID": "all",
      "periodID": "game",
      "betTypeID": "eo",
      "sideID": "odd",
      "fairOdds": null,
      "bookOdds": "-116",
      "byBookmaker": {
        "unibet": {
          "odds": "-115",
          "decimal": 1.87,
          "available": true
        },
        "tabtouch": {
          "odds": "-118",
          "decimal": 1.85,
          "available": true
        }
      }
    }
  }
}

Pair the side above with the best price on its opposingOddID, sum the implied probabilities, and you have your scan. For the full stake-sizing and middle-detection logic see the arbitrage calculator example.

SockOdds vs scraping books yourself

Frequently asked questions

Related use cases

• Odds API for Positive EV Betting: Positive EV betting API with no-vig fairOdds and every AU book's price side by side, so you can surface +EV bets without building your own devig pipeline..
• Odds Comparison & Line Shopping API: Compare bookmaker odds with one API call.
• Sports Odds API for Betting Apps: The sports betting app API with odds from every major Australian bookmaker, event status, results, and click-to-bet deeplinks in a single feed..
• Odds API for Prediction Market Arbitrage: Compare Kalshi and Polymarket prices against Australian sportsbook odds in one schema.
• Pricing: plans priced on request rate and scope, including a free Lite tier with no card.