Data timing and rights
The questions people ask before they build on FastballAPI: what the timestamps mean, how fresh each dataset is, and what the terms let you do with the data.
Timing
Measured on our own data. The data changelog shows when each dataset last refreshed.
- What does captured_at mean?
- The time of the archived snapshot the line was read from. Since October 2026 every book's game lines are captured every hour for games in the next four days, and props at 15:00 and 20:00 UTC on game day and once more in the last 75 minutes. Rows with source "final" are one pre-game line per book from a daily capture, and their captured_at is when we read them, not when the price was set.
- What are opening and closing lines?
- Lines and prices are pre-game only: anything captured at or after the start is dropped, so no in-play price is served. Opening is the first capture we hold for a game and book, which isn't always the book's very first posting; closing is the last capture before the start. From July 2020 most games have both, the opening about a day before first pitch and the closing a few minutes before. 2015 to 2019 carry one final line per book. For a delayed game the close can be captured after the scheduled first pitch but before the sportsbooks' own start time.
- Are player props pre-game?
- A row is served only if it was captured before the sportsbooks' listed start, capped at 45 minutes after the scheduled first pitch. In 2025 most games have one capture, about 4 minutes before the scheduled first pitch; about 5% of rows were captured after it, mostly for delayed games. Every row carries scheduled_start and minutes_before_scheduled_start: filter on minutes_before_scheduled_start > 0 for a strictly before-schedule cut.
- When do box scores, plate appearances and pitches update?
- Once a day at 10:00 UTC. A game is refetched for about a day and a half after it ends, then left as is. Win probability on plate appearances starts in 2019.
- What do injury statuses mean?
- The injury list as captured once a day: injured-list designations (7-, 10-, 15- and 60-day), Day-To-Day, Out and others as listed. Daily snapshots are kept from October 9 2026. A player who isn't listed isn't on that day's list. Probable pitchers aren't provided.
- Are run values and ratings as-of?
- Ratings (Elo) are recomputed every day and stored before and after each game. run_value uses a run-expectancy table rebuilt daily for the current season, so current-season values move as the season goes on; past seasons are fixed.
- Do you keep revision history?
- No. We keep the current version of each record. When a source corrects a score, stat or play, the record is overwritten, and we don't keep the earlier version, a change log per record, or a revision id. The data changelog shows when each dataset last refreshed.
- Is there a free way to tell whether a response changed?
- Not per record. Calls are charged as normal, an empty answer is refunded, and the same call repeated within two minutes is charged once.
What you can do with the data
A plain summary of the terms, which control if the two ever differ.
- Can I store the data and build on it?
- Yes. While your account is open you can store what you pull for as long as you like, derive values from it, and use it for research, backtesting and training your own models. The same terms apply on the free plan and every paid plan.
- Can I use it in a commercial product?
- Yes. You can build commercial apps, websites and tools on FastballAPI data, show your users statistics, forecasts and other values you derive from it, and show individual data points, including individual odds, in your own app or dashboard. You can sell what you generate yourself, such as probabilities or model outputs.
- What isn't allowed?
- Passing the data on as a dataset, feed, file or API of its own, or building a service that competes with FastballAPI using it. Redistributing odds, lines or prices as a raw or bulk feed or export. Presenting the data as official league data, or suggesting a league, team or player endorses you.
- What happens after I cancel?
- Data you stored while your account was open can still be used for your own internal purposes, such as research and backtesting. It doesn't cover a product that keeps serving users on the data, so keep an account open for as long as a product runs on it.
- Do you grant league rights?
- No. FastballAPI is an independent data provider, not an official league partner, so league rights, marks and the league's own reports aren't ours to grant. If your use needs the league's permission, that's between you and the league.
- Do I need to credit you or anyone else?
- Only for data from Retrosheet, which carries its own notice: "The information used here was obtained free of charge from and is copyrighted by Retrosheet. Interested parties may contact Retrosheet at www.retrosheet.org." Nothing else needs attribution.
- Where does the data come from?
- FastballAPI combines public sources and archives with its own models, and we don't publish a source list per dataset. Values we compute ourselves, such as ratings, expected goals or points and win probability, say so in each endpoint's docs.
Something not covered? Email support@fastballapi.com.