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 review — ESPN
Two different ESPN feeds, two different answers, stated plainly. The undocumented hidden JSON API is refused for ingestion — its terms restrict use to personal, non-commercial access. The public logged-off scores API (site.api.espn.com) is currently used as a score fallback in the live product for derived analytics, with the attribution “Scores data via ESPN” rendered wherever it appears. Its commercial display rights are UNVERIFIED — pending legal review. Until that review closes, ESPN data is treated as internal signal, not a licensed display feed, and is never presented as our own pricing.
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.
public-api
PROBED 2026-08-21: api.clubelo.com timed out from the founder network; clubelo.com/About is an SPA without live terms prose. Wayback 2023-01-17 About permitted reuse of calculations/rankings with citation. That archive is not a live commercial grant and is not a prohibition. Verdict stays use-with-caution (ingestible, attributed) so the existing CSV client is not killed on silence. Flip to paid-required if Lars declines; flip to cleared-with-attribution only after written confirmation.
Club Elo ratings via ClubElo / Lars Schiefler (clubelo.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.
licensed-api
Official odds vendor (DK/FD/MGM/Pinnacle + Kalshi/Polymarket, same schema). Client already exists as Odds-API failover. Free tier is self-serve; commercial display should match their plan. HOW: RUNDOWN_API_KEY. Not a scrape.
licensed-api
Third-party vendor that captures Kalshi from its own infra (not GSE calling Kalshi's Trade API). ToS §4 bans reselling/redistributing PredExon as a service; GSE analytics/picks is not a PredExon resale. Founder holds a dashboard key (Google SSO 2026-08-21). Default OFF via PREDEXON_INGEST so we do not burn quota. Do not commit the key. Native Kalshi API stays paid-required under Dev Agreement v1.1 §3.
bulk-open-data
docs.novig.com documents anonymized daily trades.csv + markets.csv on a public CDN with no authentication. Verified live 2026-08-22 (index.json lists dates through 2026-08-20). Historical tape for research/CLV — not a live line. No posted commercial-use clause, so credit and keep off the live pick path until counsel confirms.
Exchange tape via Novig public reporting CSVs (data.novig.com).
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
Developer Agreement v1.1 §3 limits API use to facilitating a member's own trading on the Exchange; §3.1 bans collecting/caching/aggregating/storing API data except for that purpose and bans sharing with third parties without prior written authorization. GSE independentFairValue is commercial derived analytics, not own-account trading. Written grant required before ingest.
bulk-open-data
moneypuck.com/data.htm: free for non-commercial purposes and journalist ad-hoc use; other purposes require inquiry. GSE is paid SaaS. Founder must obtain written permission or keep the NHL route dark.
NHL advanced stats via MoneyPuck.com.
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.
licensed-api
Vendor that publishes Kalshi implied vs US-book consensus. Live API commercial rights are a paid plan. Daily HF snapshot is CC-BY-4.0 with attribution. Do not burn the public demo Bearer from their README. HOW: buy a key, then flip this verdict to licensed.
Kalshi vs book consensus via SportsBookISH (sportsbookish.com).
bulk-open-data
621M rows of minute-by-minute player-prop odds including Bet365, DraftKings, FanDuel. Card says research/educational. Redistributing Bet365/DK/FD quotes into a paid SaaS is the same ToS class we already refuse to scrape. HOW for live props: Odds API event-odds / TheRundown / SharpAPI paid — not this tape.
licensed-api
GitHub sportsbook-json-php is an API for THEIR sportsbook's logged-in players (account, bets, casino), not a public multi-book odds dump. Market-data functions require a sales subscription. GSE is not an Entertastic operator. HOW: TheRundown / Odds API.
bulk-open-data
RooseveltHonaker/kalshi-trades-data (and TrevorJS/kalshi-trades, thomaswmitch/kalshi-prediction-markets-*) are third-party archives of Kalshi market-data API responses. The dataset card itself says users must comply with the Kalshi Developer Agreement. Dev Agreement v1.1 §3 bans collecting/caching/aggregating/storing API data except for own-account trading and bans sharing with third parties. Kalshi Data Terms (kalshi-public-docs S3 PDF) further restrict Kalshi Data to personal non-commercial use and bar ML training / redistributed archives without written consent. HOW: PredExon (vendor, key held) not the HF dump.
bulk-open-data
Academic Reddit comment dumps, not sportsbook odds or official DK/FD feeds. They do not legalize DraftKings/FanDuel HTML or hidden-API scrape. GSE already has a gated Reddit narrative path; do not treat ConvoKit as a line source.
licensed-api
Official paid odds vendor (Pinnacle as sharp reference, POWER de-vig, EV/CLV endpoints). Legal alternative to unofficial Pinnacle wrappers. GSE must hold a key AND upgrade this verdict to licensed after the founder buys a plan; do not scrape the books SharpAPI already licenses. First-party powerDevig/shinDevig stay in prediction-engine so we are not product-dependent on their EV SKU.
licensed-api
CFTC-regulated DCM. Market Data API is a read-only display/analytics SKU for partners — not the Trading API (orders/wallet). No self-serve key; apply as a display partner. Until written access, GSE does not call ProphetX. Do not scrape prophetx.co HTML.
licensed-api
Live Novig books require the authenticated API at api.novig.us (OAuth). Not a public unauthenticated odds feed. Founder-gated until we hold credentials and a commercial-use grant. Public daily CSVs are a separate source (novig-public-csv).
scrape
Pinnacle's public API closed 2025-07-23. Fair Use: commercial use without written grant = suspension. Unofficial GitHub wrappers (rozzac90/pinnacle, sth2258/pinnaclewrapper, ThiagoBoca12/Pinnacle-API, wataruoguchi/PHP-PinnacleSports-API, marcoblume/pinnacle.API) are not a license. HOW: Odds API bookmakers=pinnacle®ions=eu (already coded, LINE_ARCHIVE_EU_PINNACLE default OFF) AND/OR apply api@pinnacle.com for handicapping + written commercial grant AND/OR SharpAPI paid key.
Sourcing doctrine
