CaffeCode
每天一杯咖啡配一道題，把刷題變成習慣，輕鬆備好技術面試。
Website · Telegram Bot · LINE Bot · Getting Started · Contributing
A daily LeetCode problem delivery platform with AI-generated C++ explanations in Traditional Chinese. Browse curated problem lists on the web, connect Telegram / LINE / Email, and receive a personalized problem every day at your preferred time.
- 45 curated lists — Blind 75, NeetCode 150, NeetCode All, Grind 75, company lists (FAANG, Google, Meta, Amazon, Apple, Bloomberg, Microsoft), topic & algorithm lists
- 810+ problems with AI-generated content — explanation, C++ solution, complexity analysis, pseudocode, alternative approaches, follow-up questions
- Automated metadata sync —
sync_leetcode.pyfetches all ~3100 free LeetCode problems via GraphQL API + contest ratings - Zero runtime LLM calls — all content pre-generated offline via Claude Sonnet
- 3 notification channels — Telegram, LINE, Email; connect any combination
- 2 delivery modes — follow a list sequentially, or filter by difficulty rating + topic
- Per-user push hour — configurable delivery time in your local timezone
- Feedback & calibration — rate difficulty & content quality; system suggests optimal difficulty range
- Solve tracking — mark problems as solved from web or Telegram inline button
- Coffee Garden —
/gardengamification page: each LeetCode topic maps to a coffee variety with uncapped leveling system (Lv. 0–4 stages, then +1 per 5 solves). Auto-awarded badges for milestones, streaks, skill mastery, and variety - Streak tracking — timezone-aware daily solve streak on dashboard
- Admin monitoring — health dashboard, worker run history, per-channel test/reset
- SEO-optimized — structured data (JSON-LD), dynamic OG images, canonical URLs, web manifest, and dynamic sitemap
┌──────────────────────────┐
│ Supabase (PostgreSQL) │
│ Auth · RLS · RPC │
│ pg_cron · pg_net │
└───────────┬──────────────┘
│
hourly HTTP POST
(Bearer CRON_SECRET)
│
┌───────────┴──────────────┐
│ Next.js 16 (Vercel) │
│ │
│ Public pages (SEO) │
│ OAuth (GitHub/Google) │
│ Dashboard/Settings │
│ Admin monitoring │
│ /api/cron/push │ ← pg_cron target
│ /api/{telegram,line}/webhook
└───────────┬──────────────┘
│
┌──────────┴──────────┐
│ packages/shared │
│ │
│ Push pipeline │
│ Channel senders │
│ Problem selection │
│ Notification fmt │
└─────────────────────┘
One Next.js deployment on Vercel hosts both the site and the hourly cron endpoint. packages/shared provides the push pipeline, channel senders, problem selection, and formatters.
| Layer | Technology |
|---|---|
| Frontend | Next.js 16 (App Router), React 19, TypeScript, Tailwind CSS v4 |
| Auth | Supabase Auth (GitHub + Google OAuth) |
| Database | Supabase PostgreSQL — RLS, RPC functions, service_role access |
| Cron | Supabase pg_cron + pg_net → /api/cron/push (hourly) |
| Notifications | Telegram Bot API, LINE Messaging API, Resend (React Email) |
| Shared | @caffecode/shared — push pipeline, channel senders, problem selection, formatters |
| Monorepo | pnpm workspaces + Turborepo |
| Observability | Sentry (errors), PostHog (analytics), Pino (structured logging) |
| Security | CSP headers, Zod validation, webhook HMAC verification, timingSafeEqual auth |
| Testing | Vitest (757 TS) + Playwright E2E (57) + pytest (54 Python) |
| CI/CD | GitHub Actions, Vercel |
apps/
web/ Next.js 16 — public pages, auth, dashboard, settings, admin, cron route
packages/
shared/ Push pipeline, channel senders, problem selection, formatters
supabase/
config.toml Supabase CLI configuration
migrations/ Versioned SQL migrations (applied via Supabase CLI or MCP)
docs/
supabase-schema.sql Full schema reference
staging-setup.md Staging environment guide
content-spec.md Content generation specification
scripts/
sync_leetcode.py Fetch LeetCode metadata into data/problems/ (GraphQL + ratings)
build_database.py Data importer for lists and problems (skips metadata-only)
generate_topic_lists.py Assign orphan problems to topic-based curated lists
ipv4-only.cjs Forces IPv4 for local dev on WSL2
- Node.js 22+ (CI and Vercel use Node 24 LTS;
.nvmrcis pinned to 24) - pnpm 10+ (repo uses
packageManager: "pnpm@10.33.0"; enable viacorepack enable) - A Supabase project
git clone https://github.com/bolin8017/caffecode.git
cd caffecode
pnpm installCopy and fill in the env file:
cp apps/web/.env.example apps/web/.env.localSee apps/web/.env.example for required variables. SUPABASE_SERVICE_ROLE_KEY must be the service_role key — anon is denied by RLS.
- Create a Supabase project.
- Run
docs/supabase-schema.sqlin the SQL editor to create all tables, indexes, RLS policies, and RPC functions. - Apply migrations from
supabase/migrations/if needed. - Sync LeetCode problem metadata and import content:
# Fetch all problem metadata (titles, difficulty, ratings, topics)
python3 scripts/sync_leetcode.py # full sync (~3100 free problems)
python3 scripts/sync_leetcode.py --dry-run # preview without writing
python3 scripts/sync_leetcode.py --ids 1,42,200 # sync specific problems only
# Import problems WITH content into Supabase (metadata-only files are skipped)
python3 scripts/build_database.py --list blind75 # single list
python3 scripts/build_database.py --list all # all listspnpm build # shared → web (Turborepo manages order)
pnpm dev # start web dev server on localhost:3000WSL2 note: Dev scripts preload
scripts/ipv4-only.cjsto force IPv4 DNS resolution. WSL2 lacks IPv6, and Node.js fetch tries IPv6 first (Happy Eyeballs), causing external API calls to fail. Production is unaffected.
# All TypeScript tests via Turborepo
pnpm test
# Individually
cd packages/shared && pnpm exec vitest run # 186 tests
cd apps/web && pnpm exec vitest run # 571 tests
# E2E tests (requires dev server running)
cd apps/web && pnpm exec playwright test # 57 tests
# Python tests (sync script)
cd scripts && python3 -m pytest tests/ -v # 54 tests| Target | Platform | Method | Config |
|---|---|---|---|
| Web | Vercel | git push origin main |
GitHub integration |
| Cron trigger | Supabase pg_cron | pg_net HTTP POST hourly to /api/cron/push |
Vault secret + CRON_SECRET |
Set environment variables from each .env.example in the respective platform dashboard.
Contributions are welcome! Please read the Contributing Guide before submitting a pull request.