Dynasty League Hub

A premium Next.js hub for Sleeper fantasy football leagues with enhanced features. Works with any Sleeper league — enter a league ID or Sleeper username on the landing page, or configure a default league for your own deployment.

Features

• Dashboard: Current standings, this week's matchups, power rankings, weekly awards (top score, biggest blowout, closest call), luck index (all-play expected wins vs actual record), and recent activity
• Matchup Center: Week-by-week matchup browser with detailed lineup comparisons and all-time head-to-head records
• Draft Center: Draft board visualization, draft value analysis comparing pick value at draft time vs current value, manager rankings by draft performance, best/worst picks tracking across all seasons
• Trade Center: Trade analyzer with real-time valuations (2 and 3-team trades), trade report cards with curve grades (A+ to F) and win/loss records, historical trade browser across all seasons with value analysis at time of trade
• League History: Championship tracker, all-time records, head-to-head rivalry grid, and season-by-season archive
• Settings: League configuration display including roster positions, scoring settings, waiver rules, and trade settings
• Multi-league: All pages live under /league/<leagueId>; visitors can look up their own leagues by Sleeper username at /start

Setup

1. Install dependencies:

npm install

2. (Optional) Configure a default league in .env.local — see .env.example:

NEXT_PUBLIC_LEAGUE_ID=your_league_id_here

Without a default league, the landing page asks for a league ID or Sleeper username. Find your League ID in the Sleeper app under League Settings.

3. Run the development server:

npm run dev

4. Open http://localhost:3000 in your browser.

Environment Variables

Variable	Required	Purpose
NEXT_PUBLIC_LEAGUE_ID	No	Default league for this deployment; / redirects to it
HISTORICAL_VALUES_CSV_URL	No	Override the CSV export URL for historical player/pick values (defaults to the shared community Google Sheet)

Testing

npm test

Unit tests (vitest) cover the trade analysis engine, historical value lookups, season stats (luck index, weekly awards), and shared utilities.

Deployment to Vercel

1. Push your code to a GitHub repository
2. Import the project in Vercel
3. (Optional) Add NEXT_PUBLIC_LEAGUE_ID in Vercel's project settings
4. Deploy

Tech Stack

• Framework: Next.js 14 (App Router)
• Styling: Tailwind CSS
• API: Sleeper API (no authentication required), FantasyCalc + DynastyProcess for player values
• Testing: Vitest

Project Structure

src/
├── app/
│   ├── layout.tsx              # Root layout with navigation
│   ├── page.tsx                # Landing: redirects to default/last league or shows picker
│   ├── start/                  # League picker (league ID or username lookup)
│   └── league/[leagueId]/
│       ├── page.tsx            # Dashboard
│       ├── matchups/           # Matchup center
│       ├── draft/              # Draft center with value analysis
│       ├── trades/             # Trade center with report cards
│       ├── history/            # League history + H2H rivalry grid
│       └── settings/           # League settings display
├── components/                 # UI components (server + client)
└── lib/
    ├── sleeper.ts              # Sleeper API client (parallelized fetch helpers)
    ├── types.ts                # TypeScript types
    ├── utils.ts                # Shared helpers (team names, name normalization, CSV)
    ├── rankings.ts             # FantasyCalc / DynastyProcess player values
    ├── tradeAnalysis.ts        # Trade analysis and curve grading
    ├── seasonStats.ts          # Luck index and weekly awards
    └── historicalValues.ts     # Historical player/pick value data