Data sourcing
Every external source we ingest is declared in a registry with its real license, terms, attribution, and a legal verdict. Ingestion code checks that registry before it fetches a single row, so a source whose terms forbid commercial or automated use cannot be wired into the product. We prefer openly-licensed aggregators over scraping, we attribute what requires it, and we publish what we refuse to touch — and why.
Open-licensed or licensed feeds, used within their terms. Attribution is rendered wherever the data appears.
bulk-open-data
CC-BY-4.0 explicitly permits commercial use with attribution.
Data via nflverse (nflverse-data), licensed CC BY 4.0.
licensed-api
Commercial use in user-facing analytics is permitted; never re-expose odds as our own feed/API.
public-api
Public, keyless, read-only API; no written commercial grant published — low legal risk, attribute trending data and confirm before making load-bearing.
Player movement data via the Sleeper API.
public-api
US-government public-domain weather data — free for commercial use, no key. The clean weather source for game environments.
bulk-open-data
Complete MLB play-by-play/box history; explicitly permits commercial products with the mandated 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.
bulk-open-data
Season-level MLB stats/bios/teams; CC-BY-SA permits commercial use with attribution + share-alike.
Baseball data from the Sean Lahman Database, licensed CC BY-SA 3.0.
bulk-open-data
Global soccer fixtures/results as CC0 public domain — the cleanest legal source; no attribution required.
bulk-open-data
Free NHL shot-level + xG/win-probability CSVs back to 2008; credit MoneyPuck.
NHL advanced stats via MoneyPuck.com.
bulk-open-data
Ball-by-ball cricket across all formats; ODC-BY permits commercial use with attribution.
Cricket data via Cricsheet, licensed ODC-BY.
bulk-open-data
Free historical soccer results + closing odds (high CLV value); no formal license posted, so credit and confirm before heavy commercial reliance.
Soccer results & odds via football-data.co.uk.
Technically reachable, legally off-limits for a commercial product — or requiring spend we have not committed. We name them so the boundary is auditable, not implied.
licensed-api
Licensed DFS salary/slate feed covering DraftKings/FanDuel/Yahoo — the legal route to DK salaries. Requires a paid subscription; get a written rep that they are authorized to redistribute DK DFS salaries.
licensed-api
Licensed DFS salary/projection feed (DK/FD). A legal alternative to SportsDataIO; requires a paid plan and an authorized-redistribution rep.
scrape
DK ToU bars automated collection, commercial use, and redistribution; uncopyrightable salary facts do not cure the contract breach (hiQ v. LinkedIn), and DK enforces via cease-and-desist. Use a licensed DFS feed instead.
public-api
Clean CC-BY data, but commercial use requires a paid subscription we do not yet hold — founder-gated spend.
Weather data by Open-Meteo.com (CC BY 4.0).
public-api
ESPN ToU restricts to personal, non-commercial use and prohibits high-volume automated access.
scrape
ToS forbids automated scraping and building tools from scraped data. Use nflverse's pfr_advstats release instead.
bulk-open-data
No license granted on their outputs. Go to the nflverse source they build on instead.
scrape
ToS bars scrapers/bots; data is third-party-licensed and cannot be redistributed (custom data starts at $5,000). Use nflverse pfr_advstats / open archives instead.
scrape
No open API; ToS grants no commercial/redistribution rights. Use Statcast/Retrosheet/Lahman for open MLB data.
licensed-api
Proprietary grades behind a commercial license; no scraping. Licensable only by agreement.
bulk-open-data
Free for non-commercial/research only; the User Agreement does not grant commercial use. Off-limits for a paid product.
public-api
CC-BY-NC is non-commercial only (and the API is deprecated). Not usable in a commercial product.
scrape
No official API or commercial-use license; scraping is a ToS grey area we refuse. Use openfootball / football-data.co.uk for soccer.
Sourcing doctrine