ExamVantage | AI-Powered Exam Generator | React & Node.js Web App

ExamVantage — AI-Powered Exam Generator | React & Node.js Web App

ExamVantage is a production-ready, enterprise-grade multi-tenant SaaS platform built to automate exam generation, question bank extraction, HMAC anti-cheat verification, and multi-format document exporting. The platform comprises a centralized Node.js (Express TypeScript) REST API featuring Nodemailer SMTP email authentication, Groq AI section batching, cryptographic HMAC-SHA256 signing, and a high-performance React 18 single-page application built with TypeScript, Redux Toolkit, AES-256 CryptoJS token storage, and TailwindCSS aesthetics.

⭐ Key Highlights & Commercial USPs

• ⚡ Instant AI Paper Generation: Auto-extract chapter-wise questions and assemble complete exam papers in under 10 seconds.
• HMAC SHA-256 Anti-Cheat Stamps & QR Verification: Embedded tamper-evident 16-character cryptographic stamps and footered 2D QR codes pointing to public certificate validation portal (/verify-paper).
• Multi-Tenant School Workspaces: Dedicated organization slug routing (/tenant-slug), isolated workspace datasets, and Role-Based Access Control (Super Admin, Tenant Admin).
• 4 Dynamic School Header Branding Layouts: Live header preview customizer supporting Centered Emblem, Left Logo Right Address, Split Grid, and Bordered Box styles.
• PDF & Editable Word (.docx) Exporters: High-resolution Puppeteer Headless Chromium PDF compiler with full KaTeX + mhchem rendering engine and editable Microsoft Word compiler (docx) with inline formula baseline auto-repair.
• ✉️ Nodemailer SMTP Account Verification: 6-digit OTP email account verification and password reset recovery featuring branded HTML email templates and console fallback.
• ️ AES-256 Client Token Storage Vault: Client-side access and refresh token encryption using crypto-js via SecureStorage.
• Stripe Billing & Plan Tier Gating: Tier gating middleware (Free vs Pro vs Enterprise) and Stripe subscription webhooks.
• Generated PDF Paper Sample Preview:
  

Demo Credentials & Links (Try & Test)

• Live Web Demo URL: Launch Live Demo App
• SUPER Admin Credentials: Email: superadmin@codevantage.io | Password: password123
• TENANT Admin Credentials: Email: admin@oxford.edu.pk | Password: password123

⚠️ External Services & Upfront Cost Disclosures

IMPORTANT NOTICE TO BUYERS: ExamVantage integrates with external third-party cloud services for payment processing, media hosting, database storage, and AI inference. You must register your own accounts with these services. While free tiers are available for development, production usage carries ongoing transaction and subscription costs as detailed below:

• Stripe Payment Gateway (Paid Service): Stripe charges pay-as-you-go per-transaction processing fees. The standard fee is typically 2.9% + $0.30 per successful charge (rates vary by country and payment method). There are no setup fees or monthly minimums for standard accounts.
• ☁️ Cloudinary Media Storage (Free Tier with Paid Caps): Cloudinary is used for uploading and hosting exam school logos and question images. It includes a free tier (25 credits, approx. 25GB storage/bandwidth). High-volume usage will require moving to a paid plan (starting at $19/month).
• MongoDB Atlas Database (Free Sandbox with Paid Tiers): MongoDB Atlas hosts your SaaS cloud database. It includes a permanent free M0 sandbox cluster (512MB storage), suitable for testing. Production multi-school deployments with large databases will require moving to a paid cluster (starting at ~$9 to $57/month depending on compute resources).
• ⚡ Groq Cloud AI (Free Developer Quotas): Groq provides free developer tier quotas for high-speed AI inference (openai/gpt-oss-120b & Mixtral models). High-volume commercial workloads may require paid token usage.
• ✉️ Nodemailer SMTP Email Service: Supports free Gmail 2-Step App Passwords, SendGrid, Mailgun, and AWS SES. Includes a local development console simulator for testing without SMTP credentials.

AI Features & API Usage Disclosure

This application leverages Artificial Intelligence to power core question generation and multi-lingual translation features. An API key from Groq Cloud is required to utilize these AI functionalities.

• AI Service Provider & Models: Groq Cloud (openai/gpt-oss-120b).
• Groq AI Question Generator: Automatically generates structured multiple-choice (MCQ), short-answer, and long essay questions complete with MathJax LaTeX equations, chemical formulas, and Cloudinary diagram links.
• AI Paper Translator & Section Batching Engine: Translates entire multi-section exam papers into 6+ languages (English, Urdu, Arabic, Spanish, French, German) with right-to-left (RTL) formatting. Features a modular section-by-section batching service in ai.service.ts that permanently eliminates Groq output token truncation errors (400 json_validate_failed).
• Bloom’s Taxonomy Cognitive Balancer: Distributes questions intelligently across cognitive levels (Remembering, Understanding, Applying, Analyzing, Evaluating, Creating).

Security Note: All AI requests route securely through the Node.js backend proxy. API keys are strictly managed via the backend .env file or hot-swapped dynamically via the SuperAdmin console. They are never exposed to client devices.

Included Modules & Codebase Architecture

1. Frontend Application (React 18 / Vite / TypeScript / TailwindCSS)

• Auth Modules: Pixel-perfect screens for Login, Register, 6-digit Email OTP Notice Verification, Forgot Password, and Password Reset.
• Dashboard & Workspace Switcher: Overview showing recent exam papers, active subject count, generation quotas, and tenant switcher.
• Subjects & Chapters Syllabus Manager: Structured taxonomy builder for grade levels, subjects, chapters, and topics.
• Question Bank Generator: Interactive question manager supporting manual entry, Groq AI extraction, MathJax previewing, and difficulty weights.
• Exam Blueprint Designer: Section weightage builder, Bloom’s Taxonomy sliders, total marks allocator, and duration setting.
• Header Customizer Console: Live preview workspace to design school crests, invigilator signature lines, and select from 4 layout engines (Centered Emblem, Left Logo Right Address, Split Grid, Bordered Box).
• Paper Assembly & Scrambler Studio: Instant auto-assembly of 4 scrambled paper sets (Sets A-D) with matching answer keys.
• Document Exporter & PDF Previewer: In-browser PDF renderer with embedded QR code footers and Word (.docx) download button.
• Public Verification Certificate Portal (/verify-paper): Public validation page displaying official HMAC hash certificates.
• Super Admin Control Center: Global dashboard displaying MRR metrics, Tenants Directory, User Directory & Block Controls, Plans Manager, and System Settings.

2. Centralized Backend (Node.js / Express / TypeScript REST API)

• Auth Controller & Email Service: Handles registration, password hashing (Bcrypt), JWT generation, refresh tokens, and Nodemailer SMTP email delivery.
• AI Controller & Batching Engine: Connects to Groq API to execute AI prompts and section-by-section translation batching.
• Paper Controller & Scrambler: Generates papers, scrambles question order, and handles PDF/DOCX compilation.
• Verification Utility (verification.ts): Computes HMAC SHA-256 paper hashes and base64 QR Code data URLs.
• PDF Generator & Headless Chromium Service (pdfGenerator.ts, puppeteerPdfService.ts, pdfTemplateGenerator.ts): Compiles high-resolution vector A4 PDF documents using Puppeteer with KaTeX math & mhchem chemical reaction rendering.
• DOCX Generator & Formula Renderer (docxGenerator.ts, docxMathService.ts): Compiles editable Microsoft Word files via docx with automated OpenXML <w:position> inline formula baseline alignment.
• LaTeX Compiler Utility (latexCompiler.ts, katexCompiler.ts): Pre-processes Chemistry symbols, reaction arrows, KaTeX macros, and LaTeX math equations for export engines.
• Plan Gating Middleware (planGating.ts): Enforces tier plan limits (Free vs Pro vs Enterprise).
• Stripe Controller: Manages Stripe Checkout sessions, recurring plans, and webhook signature verification.

What You Get (Download Package Contents)

• Full Backend Source Code: Complete Node.js / Express / TypeScript REST API codebase.
• Full Frontend Source Code: Complete React 18 / Vite / TypeScript / TailwindCSS web app codebase.
• Comprehensive Buyer Documentation: Interactive web HTML documentation (docs/index.html) with non-technical guides, setup, customization, and troubleshooting guides.
• Database & Environment Configurations: Database seed scripts and .env.example template files for instant zero-config setup.
• Free Lifetime Updates: Access to all future feature releases and maintenance patches.

⚙️ Technical Specifications & Compatibility

• Software Version: v1.1.0 (PDF Engine & Math/Chemistry Upgrade)
• Node.js Engine: v18.0.0 (LTS) or higher (v20+ recommended)
• Database: MongoDB v6.0+ (Local) or MongoDB Atlas Cloud Cluster
• Frontend Stack: React 18, Vite, TypeScript, Redux Toolkit, TailwindCSS
• Backend Stack: Express.js, TypeScript, Mongoose ODM, Nodemailer
• Supported Browsers: Chrome, Firefox, Safari, Edge, Opera

Support & Contact

If you have any questions, require setup assistance, or need custom modifications, feel free to reach out:

• Email: shakeelsoftwaredev@gmail.com
• WhatsApp: +92 313 6900591