Odds API by market / MLB

MLB Run Line API

Live spreads odds across every book that posts it, in one REST call — and, unlike any other odds API, every one of those outcomes settled against the official result once play ends.

No credit card. 1,000 requests / day on the free tier.

What MLB run line is

Baseball's handicap, and it is almost always exactly ±1.5 runs — books move the PRICE rather than the number. Alternate run lines arrive in the same response.

How we settle it. Settled against the final run margin. The half-run means it cannot push.

16
books quoting it on the next event
11/12
of the next MLB events carry it right now
6,582
outcomes settled in the last 4 days

Every number on this page is measured against the live API, never copied from a spec sheet. Last measured 16 August 2026.

Books posting MLB run line

Measured live, not listed from a spec. Coverage moves — a book that has not put its board up yet will not appear until it does, which is exactly what this list is for.

BetMGMBetRiversBovadaDraftKingsFanDuelKalshiMatchbookNovig1xBetPinnaclePolymarketProphetXReBetSmarketsTABUnibet

Line shopping across all of them is one request — every book arrives in the same bookmakers array, not one call per book. Add ?bookmakers= to narrow it, or use /best-line for the best price per line already ranked.

Recently settled MLB run line outcomes

These are real rows out of the API, not an illustration. Each one was a price on a board before the event and carries the actual figure it was graded against afterwards. No other odds API returns that last column — they stop at the price.

6,582 run line outcomes settled in the last 4 days across 16 books. The 12 most recent:

BetActualResult
Kansas City Royals -2.5-3.0won
Los Angeles Angels 2.5-3.0lost
Kansas City Royals -2.5-3.0won
Los Angeles Angels 2.5-3.0lost
Kansas City Royals -3.0-3.0push
Angels 3.5-3.0won
Los Angeles Angels 3.0-3.0push
Chicago Cubs 7.5-7.0won
St. Louis Cardinals -7.5-7.0lost
Royals -3.5-3.0lost
Kansas City Royals -1.5-3.0won
Los Angeles Angels 1.5-3.0lost

Hit rate, last 4 days

50% of 6406 settled run line legs hit (3202 yes, 3204no). Counted on the YES side only — books that price this two-way contribute their Over leg, not both. That is the base rate across the whole priced field, not a per-player figure.

Read off 6,406 YES legs out of 6,582 settled outcomes on this market. The rest are the Under side from books that price it two-way, which answers a different question.

Per-player hit rates and L5 / L10 / L20 splits live on /trends.

Live response

Captured from the real endpoint on Boston Red Sox @ Pittsburgh Pirates, trimmed to one book and three outcomes so the shape stays readable. The full response carries every book and every line, alternates included, in the same call.

{
  "id": "138811",
  "sport_key": "baseball_mlb",
  "home_team": "Pittsburgh Pirates",
  "away_team": "Boston Red Sox",
  "commence_time": "2026-08-16T17:35:00Z",
  "live": true,
  "last_update": "2026-08-16T22:44:42.595376Z",
  "bookmakers": [
    {
      "key": "betmgm",
      "title": "BetMGM",
      "last_update": "2026-08-16T22:44:05.431020Z",
      "link": null,
      "book_event_id": null,
      "markets": [
        {
          "key": "spreads",
          "last_update": "2026-08-16T22:44:05.431020Z",
          "period": null,
          "suspended_at": null,
          "outcomes": [
            {
              "name": "Boston Red Sox",
              "description": "",
              "price": 500,
              "point": 4.5,
              "book_updated_at": null,
              "book_version": null,
              "payout_multiplier": null,
              "dfs_odds_type": null,
              "last_change_at": "2026-08-16T22:43:35.275750Z",
              "line_gap": null,
              "book_outcome_id": null
            },
            {
              "name": "Pittsburgh Pirates",
              "description": "",
              "price": -800,
              "point": -4.5,
              "book_updated_at": null,
              "book_version": null,
              "payout_multiplier": null,
              "dfs_odds_type": null,
              "last_change_at": "2026-08-16T22:43:35.275750Z",
              "line_gap": null,
              "book_outcome_id": null
            }
          ]
        }
      ]
    }
  ]
}

The response shape is the-odds-api compatible — events, bookmakers, markets, outcomes — so migrating is usually a base URL change.

Try it

1. List MLB events to get an event id:

curl "https://api.prop-line.com/v1/sports/baseball_mlb/events?apiKey=YOUR_API_KEY"

2. Pull run line for one game across every book — this exact URL works right now:

curl "https://api.prop-line.com/v1/sports/baseball_mlb/events/138811/odds?apiKey=YOUR_API_KEY&markets=spreads"

3. After the game, get the graded outcomes with the actual stat:

curl "https://api.prop-line.com/v1/sports/baseball_mlb/events/138811/results?apiKey=YOUR_API_KEY"

Steps 1 and 2 run on the free tier. Step 3 — prop resolution — starts on Hobby at $9/mo. See pricing.

Get your free MLB odds API key

1,000 requests / day. No credit card. The same key covers every sport and every market — not just this one.

Free tier includes 1,000 requests/day. Upgrade anytime.