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.
public-api
FOUNDER DECISION 2026-10-17: galaxy-espn-inline is the preferred free odds source for live spreads and totals. GSE reads ESPN public scoreboard inline odds (DraftKings/Circa/FanDuel/Kalshi facts via the scoreboard) with de-vig. Narrow carve-out remains: scoreboard odds/score facts only, low volume, no articles/media/bulk, no login, no evasion. Attribution required. Preferred over paid Odds API when the free path returns priced markets. Revisit immediately on any block, rate-limit signal, or C&D.
Odds facts via ESPN public scoreboard.
scrape
Founder override 2026-09-18: public page-embedded grade data only, with per-ingestion citation (time/date/URL). No API scraping; API licensable only by agreement.
Grades via Pro Football Focus public player pages.
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).
public-api
Public sabermetric leaderboards with CSV export (the endpoints pybaseball documents). Facts are not copyrightable (Feist); use as model inputs only, never re-expose the feed. Same facts-as-inputs pattern as other public sports data.
Statcast data via Baseball Savant (baseballsavant.mlb.com).
public-api
Unofficial public endpoint; facts (scores, schedules, box-score minutes) are not copyrightable (Feist). No key, no login, no evasion; derived analytics allowed, commercial DISPLAY of the feed is not — derived signals with attribution only. Narrow facts-as-inputs posture mirrors the app registry's espn-public-api row.
Scores data via ESPN
public-api
Action Network publishes public betting percentages (over/under splits) on props pages. These are facts-as-inputs (public aggregate behavior) and not copyrightable odds themselves. Attribution required; never re-expose as our own consensus feed. Verify specific endpoint terms before commercial use.
Public betting data via Action Network
public-api
VERIFIED 2026-09-18: openly served unauthenticated (HTTP 200, 322,566 bytes, 9 categories, 751 columns). FTN ToS bans automated access without prior written consent — seek permission before production ingestion; default OFF.
Charting taxonomy via FTN Fantasy Stats iQ.
public-api
VERIFIED 2026-09-18: openly served unauthenticated (HTTP 200, 14,375 bytes, 2026 regular-season cards). Same FTN ToS anti-automation clause — seek permission before production ingestion; default OFF.
Leaderboard data via FTN Fantasy Stats iQ.
scrape
VERIFIED 2026-09-18: HTTP 200, 32 team rows (play clock used, neutral rate, plays/game). Restrictive ToS — numeric facts only, no prose copying; default OFF.
Team pace stats via Sharp Football Analysis.
scrape
VERIFIED 2026-09-18: HTTP 200 (motion rate, play-action rate, air yards/att, shotgun rate). Restrictive ToS — numeric facts only; default OFF.
Offensive tendencies via Sharp Football Analysis.
scrape
VERIFIED 2026-09-18: HTTP 200 (11/12/13/21/22 personnel rates, 32 rows). Restrictive ToS — numeric facts only; default OFF.
Personnel groupings via Sharp Football Analysis.
scrape
VERIFIED 2026-09-18: HTTP 200 (man/zone/middle-closed/middle-open rates). Restrictive ToS — numeric facts only; default OFF.
Coverage schemes via Sharp Football Analysis.
scrape
VERIFIED 2026-09-18: HTTP 200 (pressure rate allowed, time to throw, yards before contact). Restrictive ToS — numeric facts only; default OFF.
Offensive line stats via Sharp Football Analysis.
scrape
VERIFIED 2026-09-18: HTTP 200 (pressure rate, no-blitz pressure rate, stuff rate). Restrictive ToS — numeric facts only; default OFF.
Defensive line stats via Sharp Football Analysis.
scrape
VERIFIED 2026-09-18: HTTP 200 (EPA/play, yards/play, points/drive, explosive play rate). Restrictive ToS — numeric facts only; default OFF.
Offensive efficiency via Sharp Football Analysis.
public-api
VERIFIED 2026-09-18: HTTP 200, TotalCount 4138 ticks/event (cash/ticket/pick %). Pregame ToS requires express written permission for automated access — seek it before production; default OFF.
Betting consensus data via Pregame.com.
public-api
VERIFIED 2026-09-18: HTTP 200, TotalCount 793 (per-book spread/total/ML ticks). Same ToS written-permission requirement; default OFF.
Odds history via Pregame.com.
public-api
VERIFIED 2026-09-18: HTTP 200 (pick types, consensus types, rotations). Same ToS written-permission requirement; default OFF.
Consensus metadata via Pregame.com.
public-api
VERIFIED 2026-09-18: HTTP 200, 10 sportsbooks with ids/names. Same ToS written-permission requirement; default OFF.
Sportsbook directory via Pregame.com.
public-api
VERIFIED 2026-09-18: HTTP 200, 8,412,344 bytes, 227 live events (eventId discovery for current games). Same ToS written-permission requirement; default OFF.
Event data via Pregame.com.
scrape
VERIFIED 2026-09-18: HTTP 200, 336 season data rows. No explicit anti-scrape clause found; redistribution restricted — facts-as-inputs only, never re-expose as a feed. Default OFF until commercial reuse is confirmed.
Historical odds via Covers.
scrape
VERIFIED 2026-09-18: HTTP 200, 2,960,182 bytes (ML/spread/total across books + consensus). Same redistribution restriction — facts-as-inputs only. Default OFF until commercial reuse is confirmed.
Live odds via Covers.
scrape
VERIFIED 2026-09-18: HTTP 200, server-rendered, no login (handle/bets% records + system definitions). Terms page 404s — attribute and keep to facts; default OFF pending terms clarity.
Betting splits analysis via VSiN (splits data via DraftKings Sportsbook).
scrape
VERIFIED 2026-09-18: HTTP 200, server-rendered (ML/spread/total with % handle + % bets per side). DK Network ToS limits to personal non-commercial use — non-commercial lane only; default OFF.
Betting splits via DraftKings Network.
scrape
VERIFIED 2026-09-18: HTTP 200, 6,608,907 bytes, 8,661 live NFL contests (sample: 'NFL $3M Fantasy Football Millionaire [$1M to 1st]' id 195648008, dg 153428, po 3000000). Website endpoint, NOT a documented public API — may change/gate without notice. Default OFF.
DFS contest data via DraftKings website endpoints.
scrape
VERIFIED 2026-09-18: HTTP 200, 363,988 bytes, 670 players for dg 153428 (sample: Bijan Robinson RB ATL vs CAR, salary 8200, ppg 31.3). draftGroupId is ephemeral per pull — resolve it from getcontests first. Default OFF.
DFS player pool data via DraftKings website endpoints.
bulk-open-data
VERIFIED 2026-09-18: HTTP 200, 14,164 rows, seasons 1966–2025 (11,671 rows with spreads). No license posted on the source repo — terms unclear; default OFF.
Historical scores and lines via SpreadSpoke.
scrape
VERIFIED 2026-09-18: HTTP 200, 2,609,656 bytes, 500 players in <script id="ktc-players"> JSON (1QB/SF/TEP values, ranks, tiers, trends). Public page, robots allow.
Dynasty values via KeepTradeCut.
scrape
VERIFIED 2026-09-18: HTTP 200, var ecrData (560 players x 179 experts). Public free page; the paid API is a separate SKU we do not touch.
Expert consensus rankings via FantasyPros.
public-api
VERIFIED 2026-09-18: HTTP 200s (7 live NFL slates). Undocumented internal endpoints — may change/gate without notice; default OFF.
Slate data via Underdog Fantasy.
public-api
VERIFIED 2026-09-18: HTTP 200, 1,690 appearances (points/adp/salary/position_rank). player_id only — names must join from another source. Default OFF.
Projections via Underdog Fantasy.
scrape
VERIFIED 2026-09-18: HTTP 200, 9 tables (overall/positional/superflex/flex/K/DEF; stamped 2026-09-09). Public free page, robots allow.
Rankings via 4for4.
bulk-open-data
VERIFIED 2026-09-18: HTTP 200, values-players.csv (442 players: ecr/value 1QB+2QB). Open repo with LICENSE; attribution appreciated per repo norms.
Dynasty values via DynastyProcess (CC/open data).
public-api
VERIFIED 2026-09-18: HTTP 200 (week 2, season 2026). Reconciled with standing 'sleeper' entry: free for non-commercial use; no written commercial grant. Default OFF.
NFL state via the Sleeper API.
public-api
VERIFIED 2026-09-18: HTTP 200, 14,656,940 bytes, 12,228 players with full cross-platform ID map (espn/yahoo/rotowire/gsis/sportradar/opta/fantasy_data/kalshi/oddsjam/swish). Same non-commercial terms; default OFF.
Player data via the Sleeper API.
public-api
VERIFIED 2026-09-18: HTTP 200 (top add: 515,538 adds/24h). Same non-commercial terms; default OFF.
Waiver sentiment via the Sleeper API.
scrape
VERIFIED 2026-09-18: HTTP 200, 321,517 bytes (rank, rating, proj W/L, playoff/SB %). Public free pages; scrape politely.
Power ratings via TeamRankings.
scrape
VERIFIED 2026-09-18: HTTP 200, 315,324 bytes (team win-trends table). Public free pages; scrape politely.
Win trends via TeamRankings.
public-api
VERIFIED 2026-09-18: HTTP 200, valid RSS 2.0 (5 items with title/pubDate/link). Standard RSS fair-use: attribute + link back, never republish full text.
News headlines via RotoWire.
bulk-open-data
VERIFIED 2026-09-18: 1,993 rows, seasons 2023–2026, 18 columns (total/off/def/ST DVOA + DAVE). Extracted from public articles; attribution required.
DVOA data via FTN Fantasy / Football Outsiders.
bulk-open-data
VERIFIED 2026-09-18: 112 rows (1977–1980 season finals, pre-1981). Attribution required.
Historical DVOA via FTN Fantasy.
bulk-open-data
VERIFIED 2026-09-18: 1,673 rows from 57 web.archive.org snapshots (weekly + season-final 1981–2022). Attribution required.
DVOA data via Football Outsiders (archived).
public-api
VERIFIED 2026-09-18: HTTP 200, 599,785 bytes, 145 paths (machine-readable map of the FTN Charting data API). Spec is public; runtime auth per endpoint UNVERIFIED — treat data endpoints as gated until proven otherwise; default OFF.
API map via FTN Charting public docs.
scrape
VERIFIED 2026-09-18: HTTP 200 (after one 302), 176,257 bytes, full 1983 season-final table (TOTAL/NON-ADJ DVOA, W-L, OFF/DEF/ST + ranks). Attribution required.
1983 DVOA via Football Outsiders (archived).
public-api
Official OpenLigaDB page states no registration, API key, or quota and licenses the data under ODbL 1.0. Commercial use is permitted with attribution; ODbL share-alike applies to derived databases — keep derived tables attributed and share-alike compliant.
Data via OpenLigaDB (ODbL 1.0).
public-api
TheSportsDB documents free and premium API versions and labels itself a free/open crowd-sourced database. Free tier is suitable for schedule/team/player metadata with attribution; do not treat artwork assets as freely redistributable without checking terms.
Sports metadata via TheSportsDB.
public-api
OpenF1 describes itself as an open-source API for live and historical F1 session data (lap times, sectors, speed traps, telemetry). No commercial redistribution grant is asserted on the cited page — use as model inputs with attribution; confirm license before any re-exposure.
F1 session data via OpenF1.
public-api
Teams must report injuries, illnesses, medical conditions or rest with participation status and reason; deadlines are specified. This is a direct availability signal. Public page, not an API license — extract facts as model inputs only; never re-expose the report feed. Check NBA terms before systematic extraction.
Injury/availability status via NBA official injury report.
public-api
Official NFL injury report with injury, practice status and game status by player and team — a direct availability signal. Publicly viewable but not a scraping/redistribution license; extract facts as model inputs only, never re-expose the feed. Prefer licensed injury feeds (e.g. SportsDataIO) for production display.
Injury/availability status via NFL official injury report.
public-api
MLB injury-report pages organize reports by league/team and link to official transaction pages (injured-list placements, activations, roster moves). Public editorial content, not an API license — facts as model inputs only; never re-expose the feed. Check MLB terms before systematic extraction.
Injury/transaction status via MLB official reports.
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. General/bulk ESPN JSON stays forbidden; the ONE narrow carve-out is 'galaxy-espn-inline' (scoreboard inline odds facts, low volume, facts-only posture) — see that entry.
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.
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.
licensed-api
Broad multi-sport schedules, rosters, play-by-play and historical feeds (80+ sports, 500+ leagues). Production access requires a Sportradar account/contract or key; no free or open license on the developer portal. Founder-gated until a contract and redistribution rights are in hand.
licensed-api
Official low-latency live/historical data, play-by-play, and player/ball tracking (speed, acceleration, location, derived metrics) for NFL, NCAA and other leagues. Commercial terms must be confirmed with Genius Sports; not free/open.
licensed-api
REST API covering live game statistics, player/team situational statistics, historical data, editorial content and common IDs; Opta adds event data and betting/fantasy feeds. Access key required; contact Stats Perform. Not free/open.
licensed-api
Multi-sport API products (football, AFL, baseball, basketball, F1, hockey, NBA, NFL/NCAA, rugby, etc.) with basic and advanced data. No open license; access limits and commercial rights must be checked in the selected plan. Founder-gated.
licensed-api
Machine-readable football fixtures, results, tables, teams, squads, lineups and scorers. Documentation notes paid tiers and token auth; the free tier does not grant blanket commercial redistribution. Use the free tier only for non-commercial exploration until a plan is held.
licensed-api
Live scores, fixtures, match events, statistics, lineups, xG and predicted lineups across 2,200+ leagues. Free tier exists for exploration; production limits and redistribution rights require a paid plan. Founder-gated until a plan and redistribution terms are confirmed.
licensed-api
Sleep, recovery, HRV, resting HR, strain and workout resources. Member-data developer API requiring OAuth/member authorization. Health data is sensitive: requires athlete consent, minimization, access controls, and a separate sensitive-data plane. Founder-gated until consent + legal basis exist.
licensed-api
Daily sleep, sleep stages/timing, readiness, heart rate and breathing. Account/token-based access; no blanket public-data or redistribution license. Health data requires privacy controls, athlete consent, and a separate sensitive-data plane. Founder-gated.
Sourcing doctrine