Product architecture

Plan the assistant, then wire the world

Homefield is one brain for two jobs: Season desks grounded in your connected league rules, and DraftKings-classic DFS you export and submit yourself. Live host sync is Sleeper + CBS today — not Yahoo or ESPN. Multi-sport Season desks include honest demos; Homefield DFS prioritizes NFL + UFC.

Jobs to be done

Thursday night: set the season-long lineup before a questionably-active starter ruins the week. Sunday morning — or tip-off, or first pitch — turn a GPP take into unique lineups that still look like that take.

The assistant fails if it hallucinates news, silently double-starts a player, or optimizes DFS as if cash and tournaments were the same contest.

One brain, two objectives

Season-long: maximize expected scoring among players you actually roster, with a penalty for injury and weather. Waivers are replacement-level math against your worst bench seat — under your host rules.

DFS: maximize contest-aware utility under DraftKings-classic salary and slots. GPP utility is ceiling × leverage. Cash utility is floor. Homefield exports CSV; you submit.

System layers

1. Data plane

▸ Identity: player, team, game, slate
▸ Environment: Vegas (when live), weather, injury tags
▸ Market: salary via CSV · Own% only when labeled (demo/CSV) — no ADP feed or ownership sims
▸ Projections: floor / median / ceiling with asOf freshness

2. Decision engines

▸ Season ranker (start/sit, compare, FAAB)
▸ Analyst questions hit that compare engine
▸ Pass / game / team stacks (DK classic)
▸ DFS greedy, uniqueness, exposure — not FantasyLabs portfolios

3. AI layer

▸ Tool-calling only, no free stats
▸ Contest-aware copy on DFS; league-true on Season
▸ Explicit uncertainty (Q tags)
▸ Dead session: show reconnect, don't loop

4. Product surfaces

▸ Weekly desk + Sleeper/CBS sync (/season)
▸ Start/sit compare + trade fairness
▸ Draft · Keeper/Dynasty · Best Ball
▸ DFS studio (/dfs) — DK-classic first
▸ War Room · Rivalry · Multi-league HQ

Data you should not scrape

Official DFS salaries and contest entry belong to the operator. Plan for CSV upload or a licensed feed — Homefield exports; humans submit.

League rosters: Sleeper (public username) and CBS (bookmark token) are live today. Yahoo and ESPN sync are not supported — do not claim them until adapters ship.

News needs a timestamped source. If the feed is late, the UI must say the injury file is stale rather than sounding confident.

What this optimizer already encodes

Sport-native DraftKings construction, injury haircuts, cash vs GPP utility, optional stacks, NFL bring-backs, min unique players, max exposure, and a swap search that will not rerun a locked player. FanDuel classic only where real slot maps exist — never a fake DK layout.

It is intentionally a fast heuristic, not a full MIP, and not an ownership-field or multi-entry portfolio simulator.

Build sequence

Shipped — desks + sync

Season desks across American sports (live Sleeper/CBS for NFL/NBA/MLB/NHL; honest demos elsewhere). Draft / Keeper / Best Ball league-true polish. Multi-league HQ. War Room slate + You vs Homefield rivalry. DraftKings-classic DFS (NFL + UFC priority; NBA/NHL/MLB classic demos; MLS/PGA/NASCAR calendar demos — not multi-sport parity) with late-swap honesty and DK-first platform roles — FanDuel only with real maps; pick’em helpers are not Homefield DFS.

Shipped — live inputs + Ask

Sleeper weekly stats, injury tags, trending adds, and NFL kickoff windows (ESPN scoreboard with schedule-only fallback labeled). Connected leagues rescore to host categories. Tool-gated Ask via /api/analyst/ask with citations/asOf. Free Hugging Face cascade with optional OpenAI fallback.

Next — still honest gaps

Yahoo / ESPN adapters only behind a real SyncRequest (not fake UI). Live tip-off / puck-drop feeds for NBA/NHL/MLB DFS (desks stay classic-demo until then). Weekly accuracy email rolling out to Pro cohorts (Resend domain live). Opt-in public hit-rate aggregates only after privacy call.

Never — anti-goals

No password scraping, no auto-enter contests, no inventing FLEX/injuries/news, no public “#1” / “most accurate” claim without your lock ledger, no ownership-field simulations marketed as live.

What we do not claim

▸Yahoo / ESPN sync “supported”
▸FanDuel / PrizePicks / Underdog as Homefield DFS parity
▸Multi-sport DFS parity / every DFS sport live
▸Ownership % sims / multi-entry FantasyLabs boards
▸Native store listing (PWA only for now)
▸"Every sport live-synced" (demo desks stay labeled)

Risks to keep on the whiteboard

LLM hallucinated injuries will lose leagues. Tool-gating is not optional.

Site ToS usually forbids bots that enter contests. Export CSV; humans submit.

Projection vendors disagree. Ensemble + show the range, do not pick a cult source.

This is analysis software, not gambling advice. Keep that line in the product copy.