A sophisticated full-stack chess application with an intelligent AI companion named Chester.

Play Now: chesterchess.com

All scores verified via Lighthouse (incognito), SSL Labs, and production header inspection.

• Play Chess: Full chess rules with castling, en passant, and promotion
• AI Opponent: Intelligent minimax engine with adaptive difficulty
• Chester AI: Your witty chess companion who comments on moves and offers advice
• Real-time Streaming: Character-by-character AI responses
• Mobile Ready: Responsive design with PWA support
• Subscription Tiers: Free, Pro, and Premium plans

• Frontend: Next.js 16, React 19, TypeScript, Tailwind CSS
• Backend: Next.js API Routes, Server-Sent Events
• Database: Supabase (PostgreSQL with Row Level Security)
• Auth: Supabase Auth (Email/Password + Google OAuth)
• Payments: Stripe (Subscriptions + Customer Portal)
• AI: OpenAI Responses API (GPT-5 series) for Chester's commentary
• Chess: chess.js + react-chessboard
• Testing: Vitest + React Testing Library
• Linting: Biome (lint + format)
• CI/CD: GitHub Actions
• Monitoring: Sentry (Error tracking + Session replay)
• Rate Limiting: Upstash Redis

• Node.js 18+
• Bun (package manager + runtime)
• Supabase account
• Stripe account
• OpenAI API key

# Clone the repo
git clone https://github.com/Nxtvanhalen/ai-chess.git
cd ai-chess

# Install dependencies
bun install

# Set up environment variables
cp .env.example .env.local
# Edit .env.local with your credentials

# Run development server
bun run dev

# Supabase
NEXT_PUBLIC_SUPABASE_URL=
NEXT_PUBLIC_SUPABASE_ANON_KEY=
SUPABASE_SERVICE_ROLE_KEY=

# OpenAI
OPENAI_API_KEY=

# Stripe
STRIPE_SECRET_KEY=
STRIPE_WEBHOOK_SECRET=
NEXT_PUBLIC_STRIPE_PUBLISHABLE_KEY=

# Upstash Redis
UPSTASH_REDIS_REST_URL=
UPSTASH_REDIS_REST_TOKEN=

# Sentry (optional)
NEXT_PUBLIC_SENTRY_DSN=
SENTRY_ORG=
SENTRY_PROJECT=
SENTRY_AUTH_TOKEN=

bun run dev          # Development server
bun run build        # Production build
bun run start        # Start production server
bun run lint         # Biome check
bun run lint:fix     # Biome check + autofix
bun run format       # Biome formatter
bun test             # Run tests
bun run test:watch   # Watch mode
bun run test:coverage # Coverage report

src/
├── app/                    # Next.js App Router
│   ├── api/               # API Routes
│   │   ├── chess/         # Game endpoints
│   │   ├── chat/          # Chester AI endpoints
│   │   ├── stripe/        # Payment endpoints
│   │   └── subscription/  # Usage tracking
│   ├── login/             # Auth pages
│   ├── pricing/           # Subscription plans
│   └── page.tsx           # Main game page
├── components/
│   ├── auth/              # LoginGate
│   ├── chess/             # ChessBoard, ThemeSelector
│   ├── chat/              # ChatInterface
│   ├── layout/            # GameLayout
│   └── subscription/      # UsageDisplay, UpgradeModal
├── lib/
│   ├── chess/             # Engine, themes
│   ├── openai/            # AI client, prompts
│   ├── supabase/          # DB client, subscriptions
│   ├── middleware/        # Rate limiting
│   └── redis/             # Upstash client
└── __tests__/             # Vitest tests

• Authentication: Supabase Auth with secure sessions
• Authorization: Row Level Security on all database tables
• Rate Limiting: Redis-backed sliding window algorithm
• Input Validation: Zod schemas on all API endpoints
• Headers: CSP, HSTS, X-Frame-Options, etc.
• Payments: Stripe webhook signature verification

GitHub Actions pipeline runs on every push and PR to main:

• Lint — Biome static analysis
• Build — Next.js production build
• Test — Vitest suite (40 tests across 6 suites)

bun test               # Run all tests
bun run test:watch     # Watch mode
bun run test:coverage  # Coverage report

40 tests across 6 suites:

• API route validation (chat, streaming)
• LoginGate component
• UpgradeModal component
• Rate limiting middleware
• Subscription utilities
• UUID generation

1. Connect GitHub repo
2. Set environment variables
3. Deploy

1. Import from GitHub
2. Set environment variables
3. Auto-deploys on push

• Configure Stripe webhook endpoint
• Set up daily cron job for reset_daily_usage()
• Verify Sentry is receiving events

1. Fork the repo
2. Create a feature branch
3. Make your changes
4. Run tests: bun test
5. Submit a PR

AGPL-3.0 — See LICENSE for details.

Chris Bergstrom - GitHub

Built with ❤️ and a lot of chess games against Chester.