Lectgen AI

Built with

AI-Powered Presentation Generation Platform

Transform your ideas into professional presentations using text, voice, or template images.

Features • Architecture • Tech Stack • Getting Started • API Documentation

Overview

Lectgen AI is an intelligent presentation generation platform that leverages advanced AI models to automatically create professional slide decks. Users interact through an intuitive ChatGPT-style interface with support for multimodal inputs including text descriptions, voice recordings, and template images.

Key Features

🤖 AI-Powered Generation - Utilizes Google Gemini via LangChain for intelligent content creation
🎙️ Voice Input - Convert speech to presentations with Whisper speech-to-text
🎨 Template Analysis - Upload reference slides to match your desired style
💬 Conversational Interface - ChatGPT-like experience for iterative design
👥 Multi-tier System - FREE and VIP plans with different capabilities
📊 Admin Dashboard - Comprehensive analytics and user management

Problem Statement

Time-consuming - Educators and students spend hours creating presentations
Design challenges - Not everyone has design expertise or access to quality templates
Inefficient workflows - Need rapid conversion from ideas (text/voice) to finished slides

Architecture

System Overview

┌─────────────────┐      ┌──────────────────────────────────────┐      ┌──────────────┐
│    Frontend     │─────▶│            Backend                   │─────▶│   Database   │
│  React + TS     │◀─────│          Node.js + TS                │◀─────│  PostgreSQL  │
└─────────────────┘      │                                      │      └──────────────┘
                         │  ┌────────────────────────────────┐  │
                         │  │  LangChain → Gemini AI         │  │
                         │  │  Generate Content Structure    │  │
                         │  └────────────────────────────────┘  │
                         │              ↓                       │
                         │  ┌────────────────────────────────┐  │
                         │  │  Backend LaTeX Builder         │  │
                         │  │  Content → LaTeX Code          │  │
                         │  └────────────────────────────────┘  │
                         │              ↓                       │
                         │  ┌────────────────────────────────┐  │
                         │  │  LaTeX Compiler                │  │
                         │  │  LaTeX → PDF                   │  │
                         │  └────────────────────────────────┘  │
                         └──────────────────────────────────────┘
                               │
                               ├─▶ MinIO (Storage)
                               └─▶ Whisper (STT)

Core Components

Frontend Architecture

frontend/src/
├── pages/
│   ├── Auth/         # Authentication pages
│   ├── Dashboard/    # Main chat interface
│   ├── Settings/     # User preferences
│   ├── Payment/      # Subscription management
│   └── Admin/        # Admin panel
├── components/       # Reusable UI components
├── hooks/           # Custom React hooks
└── services/        # API integration layer

Main Interface Features:

Chat Area - Conversation history with slide previews and download options
Input Panel - Three modes: Text, Audio, and Template upload
Sidebar - Conversation history, user profile, and usage statistics
Settings - Account management and subscription controls

Backend Architecture

backend/src/modules/
├── auth/          # JWT-based authentication
├── user/          # User profile management
├── conversation/  # Chat session handling
├── chat/          # Message processing
├── ai/            # LangChain + Gemini integration (content generation)
├── latex/         # LaTeX builder (convert content → LaTeX syntax)
├── speech/        # Whisper STT service
├── template/      # Image style analysis
├── file/          # MinIO file operations
└── admin/         # Analytics and monitoring

Data Flow

Text to Slides:

User Input → Chat API → LangChain + Gemini (Generate Content) →
Backend LaTeX Builder (Content → LaTeX) → LaTeX Compiler → PDF → Storage

Voice to Slides:

Audio Upload → Whisper STT → Text → Chat API → LangChain + Gemini (Generate Content) →
Backend LaTeX Builder → LaTeX Compiler → PDF

Template-based:

Image Upload → Vision Analysis → Style Prompt → LangChain + Gemini (Generate Content) →
Backend LaTeX Builder (Apply Style) → LaTeX Compiler → PDF

Tech Stack

Frontend

Framework: React 18 + TypeScript
Styling: Tailwind CSS + Ant Design
State Management: React Context / Redux
Build Tool: Vite / Webpack

Backend

Runtime: Node.js 20+
Framework: Express.js + TypeScript
ORM: Sequelize
Authentication: JWT (HTTP-only cookies)

Database & Storage

Primary DB: PostgreSQL
File Storage: MinIO (S3-compatible)
Session Store: Redis (optional)

AI & ML Services

AI Framework: LangChain
LLM Model: Google Gemini API (gemini-1.5-flash, gemini-2.0-flash-exp)
- Role: Generate structured content (titles, sections, bullet points)
Speech-to-Text: OpenAI Whisper
LaTeX Builder: Backend service to convert content structure → LaTeX syntax
LaTeX Compilation: Backend LaTeX Compiler (TexLive/MiKTeX)
PDF Generation: Complete pipeline: Content → LaTeX → PDF

DevOps

Containerization: Docker + Docker Compose
CI/CD: GitHub Actions
Monitoring: (To be configured)

Database Schema

Core Tables

Users

id, email, name, avatarUrl, passwordHash
role (FREE/VIP/ADMIN), slidesGenerated, maxSlidesPerMonth
subscriptionExpiresAt, createdAt, updatedAt

Conversations

id, userId, title, createdAt, updatedAt

Messages

id, conversationId, role (USER/ASSISTANT), messageType (TEXT/AUDIO/IMAGE)
contentText, audioUrl, imageUrl, transcript, styleAnalysis (JSONB)
pdfUrl, slideCount, createdAt

Sessions

id, userId, refreshToken, expiresAt

UsageLogs

id, userId, actionType, status, metadata (JSONB), createdAt

Getting Started

Prerequisites

Node.js 20+ and npm
Docker & Docker Compose
PostgreSQL 14+
MinIO server (or S3-compatible storage)

Environment Setup

Clone the repository

git clone git@github.com:The-GenLab/Lectgen-AI.git
cd Lectgen-AI

Configure environment variables

cp .env.example .env
# Edit .env with your API keys and configuration

Install dependencies

# Root dependencies
npm install

# Backend dependencies
cd backend && npm install

# Frontend dependencies
cd ../frontend && npm install

Start development environment

# Using Docker Compose
docker-compose -f docker-compose.dev.yml up

# Or manually
npm run dev

Access the application

Frontend: http://localhost:3000
Backend API: http://localhost:8000
MinIO Console: http://localhost:9001

Project Structure

Lectgen-AI/
├── backend/              # Node.js backend service
├── frontend/             # React frontend application
├── scripts/              # Utility scripts
├── AI_doc/              # AI service documentation
├── docker-compose.dev.yml
├── Dockerfile.backend.dev
└── README.md

API Documentation

Authentication Endpoints

POST /api/auth/register - User registration
POST /api/auth/login - User login
POST /api/auth/refresh - Refresh access token
POST /api/auth/logout - User logout

Chat Endpoints

POST /api/chat/message - Send text message
POST /api/chat/audio - Upload audio for transcription
POST /api/chat/template - Upload template image
GET /api/chat/conversations - List user conversations
GET /api/chat/conversations/:id - Get conversation details

User Endpoints

GET /api/user/profile - Get user profile
PUT /api/user/profile - Update profile
POST /api/user/upgrade - Upgrade to VIP

Admin Endpoints

GET /api/admin/stats - System statistics
GET /api/admin/users - User management
GET /api/admin/logs - Usage logs

Feature Tiers

FREE Plan

✅ 5 presentations per month
✅ Text input only
✅ Basic templates
✅ Standard processing speed

VIP Plan

✅ Unlimited presentations
✅ Text + Audio + Template inputs
✅ Premium templates with icons & charts
✅ Priority queue processing
✅ Advanced AI model (Gemini 2.0)

Storage Structure (MinIO)

buckets/
├── audio-recordings/    # User audio uploads
├── template-images/     # Reference slide images
├── avatars/            # User profile pictures
└── latex-files/        # Generated LaTeX documents

Contributing

This is a private project developed by The GenLab team. For internal contributors:

Create a feature branch from develop
Make your changes following the coding standards
Submit a pull request with detailed description
Ensure all tests pass before requesting review

License

Team

Developed by The GenLab team

Project Duration: 2 months
Team Size: 5 developers

Support

For issues and questions, please contact the development team or create an issue in the repository.

Built with ❤️ by The GenLab

Name		Name	Last commit message	Last commit date
Latest commit History 135 Commits
backend		backend
docs/img		docs/img
frontend		frontend
scripts		scripts
.dockerignore		.dockerignore
.env.example		.env.example
.gitignore		.gitignore
Dockerfile.backend.dev		Dockerfile.backend.dev
Dockerfile.frontend.dev		Dockerfile.frontend.dev
README.md		README.md
docker-compose.dev.yml		docker-compose.dev.yml
package-lock.json		package-lock.json
package.json		package.json

Uh oh!

Folders and files

Latest commit

History

Repository files navigation