CertBench

Adaptive exam prep for CompTIA certifications — live at certbench.dev.

CertBench builds a personalised daily study plan from your actual performance: a confidence-penalised readiness score, adaptive practice exams, SM-2 spaced repetition, hands-on PBQ simulations, and AI-generated study sets from your own notes.

Certifications: Security+ SY0-701 · Network+ N10-009 · A+ Core 1 220-1101 · A+ Core 2 220-1102

Stack

• Next.js 16 (App Router, React 19) on Vercel
• Supabase — Postgres (RLS everywhere) + Auth (password & Google OAuth)
• Tailwind CSS v4 with a shadcn-style token system (light + dark)
• Zod v4 — end-to-end typed API contracts shared client/server
• Anthropic API — AI question generation with a two-pass quality review
• Stripe — Pro subscriptions (checkout, portal, webhook sync)

See docs/ARCHITECTURE.md for the layering rules and docs/DATABASE.md for the schema contract.

Local development

npm install
cp .env.example .env.local   # fill in the values (see below)
npm run dev                  # http://localhost:3000

Required in .env.local for a working app:

Variable	Purpose
NEXT_PUBLIC_SUPABASE_URL / NEXT_PUBLIC_SUPABASE_ANON_KEY	Supabase project (RLS-scoped access)
SUPABASE_SERVICE_ROLE_KEY	Admin client (webhook, rate limiter, account deletion)
ANTHROPIC_API_KEY	AI question generation (503s cleanly if absent)
STRIPE_SECRET_KEY / STRIPE_WEBHOOK_SECRET / STRIPE_PRO_PRICE_ID	Billing (use TEST keys locally)

src/env.ts is the authority: public vars are validated at boot, secrets at point of use — a missing Stripe key never breaks non-Stripe features.

Note: the Supabase free tier pauses the project after inactivity, which drops its DNS records. If the DB is unreachable, resume it from the Supabase dashboard.

Commands

npm run dev            # dev server
npm run build          # production build
npm test               # vitest (core behavioural locks + contract tests)
npm run lint           # eslint (includes architecture-boundary rules)
npm run typecheck      # tsc --noEmit
npm run db:types       # regenerate src/types/database.gen.ts (needs SUPABASE_ACCESS_TOKEN)
npm run db:types:check # CI drift check against the live schema

Deployment

Pushes to main deploy to production via Vercel. Preview deployments run against the same production database (RLS confines writes to the acting user) — use dedicated +test accounts on previews and TEST-mode Stripe keys in the Preview environment. New migrations in supabase/migrations/ must be additive and are applied manually via the Supabase SQL editor.