NoHell

NoHell is a learning companion for long YouTube coding tutorials. It turns passive watching into guided study with AI-generated checkpoints, in-session notes, revision cards, and recap prompts.

The current app is built with Next.js, React 19, Clerk, Supabase, Groq, and Razorpay.

What It Does

• Paste a YouTube tutorial URL and define a learning goal.
• Generate 3 to 5 checkpoints based on the transcript or, if captions are unavailable, from the tutorial title and goal.
• Save sessions, notes, usage, and onboarding data in Supabase.
• Personalize checkpoint generation with onboarding answers like level, tech focus, and note style.
• Enforce a free-tier limit of 5 sessions and unlock unlimited sessions with the Pro plan.
• Upgrade users through Razorpay payment verification or webhook handling.

Stack

• next@15
• react@19
• @clerk/nextjs for authentication
• @supabase/supabase-js for persistence
• groq-sdk for AI generation
• razorpay for payments
• tailwindcss@4

Local Setup

1. Install dependencies

npm install

2. Create environment variables

Create .env.local in the project root and add:

# Clerk
NEXT_PUBLIC_CLERK_PUBLISHABLE_KEY=
CLERK_SECRET_KEY=

# Supabase
NEXT_PUBLIC_SUPABASE_URL=
NEXT_PUBLIC_SUPABASE_ANON_KEY=
SUPABASE_SERVICE_ROLE_KEY=

# Groq
GROQ_API_KEY=

# Razorpay
RAZORPAY_KEY_ID=
RAZORPAY_KEY_SECRET=
NEXT_PUBLIC_RAZORPAY_KEY_ID=
RAZORPAY_WEBHOOK_SECRET=

# Optional external transcript provider
YOUTUBE_TRANSCRIPT_PROVIDER_URL=
YOUTUBE_TRANSCRIPT_PROVIDER_TOKEN=

# Optional Razorpay overrides
RAZORPAY_ORDER_CURRENCY=USD
RAZORPAY_ORDER_AMOUNT_MINOR=900

Notes:

• SUPABASE_SERVICE_ROLE_KEY is the recommended server-side configuration. Without it, some server helpers fall back to the public client.
• GROQ_API_KEY is optional. If it is missing, NoHell falls back to a simpler checkpoint generator.
• NEXT_PUBLIC_RAZORPAY_KEY_ID is optional and falls back to RAZORPAY_KEY_ID.
• YOUTUBE_TRANSCRIPT_PROVIDER_URL is optional. If set, NoHell will try that provider before the built-in Node transcript fetcher.
• YOUTUBE_TRANSCRIPT_PROVIDER_TOKEN is optional bearer auth for that provider.
• The default Pro price is $9/month.

3. Bootstrap Supabase

Run the SQL in supabase-schema.sql in the Supabase SQL Editor.

That creates:

• users
• sessions
• notes
• bookmarks

The schema currently enables permissive RLS policies for development. Tighten those before production.

4. Start the app

npm run dev

Open http://localhost:3000.

Production Transcript Fallback

If transcript loading works locally but fails after deployment, that is usually an IP reputation problem, not just a library problem. This repo includes tools/youtube_transcript_proxy.py, a small Python HTTP bridge around youtube-transcript-api.

Install it on a separate machine or service:

pip install youtube-transcript-api
python tools/youtube_transcript_proxy.py

Then point the Next.js app at it:

YOUTUBE_TRANSCRIPT_PROVIDER_URL=https://your-transcript-host/transcript
YOUTUBE_TRANSCRIPT_PROVIDER_TOKEN=your-shared-secret

Optional proxy settings for the Python service:

WEBSHARE_PROXY_USERNAME=
WEBSHARE_PROXY_PASSWORD=
WEBSHARE_FILTER_IP_LOCATIONS=us,in

# or generic proxies
YT_HTTP_PROXY_URL=
YT_HTTPS_PROXY_URL=

Optional transcript service settings:

YT_TRANSCRIPT_LANGUAGES=en
YT_TRANSCRIPT_PRESERVE_FORMATTING=false
YOUTUBE_TRANSCRIPT_PROXY_PORT=8787

Scripts

npm run dev
npm run dev:clean
npm run build
npm run start
npm run lint

Product Flow

1. A user lands on the homepage and pastes a YouTube URL.
2. Signed-out users are redirected into Clerk auth.
3. Signed-in users enter a learning goal and start a session.
4. The server fetches transcript data, generates checkpoints, creates a session, and increments usage.
5. New users complete onboarding before hitting pricing.
6. Free users can start up to 5 sessions. Pro users have no session cap.

Important Routes

• / landing page and session start flow
• /onboarding learning profile capture
• /pricing upgrade screen
• /session/[sessionId] active learning session
• /session/[sessionId]/recap post-session recap

API Surface

• /api/session/start creates a session and generates checkpoints
• /api/session/end finishes a session and can generate recap content
• /api/notes/generate creates AI notes during a session
• /api/revision/card generates revision cards
• /api/user/onboarding reads and saves onboarding answers
• /api/user/usage returns free/pro usage state
• /api/payment/create-order creates a Razorpay order
• /api/payment/verify verifies a Razorpay payment client-side
• /api/payment/webhook handles Razorpay webhooks server-side

Current Limits And Assumptions

• Transcript fetching depends on public YouTube captions and may be unavailable for some videos or hosting environments.
• Middleware is currently configured with an empty protected-route matcher, so route protection is opt-in.
• Supabase policies are development-friendly and should be hardened for production.

Repo Structure

src/app/                  App Router pages and API routes
src/components/           UI components
src/lib/                  transcript, pricing, Supabase, and billing helpers
src/types/                shared types
public/                   static assets
supabase-schema.sql       database bootstrap