# Fractal Chat **Fractal Chat** is an AI-powered reader application that enables users to interact with their documents (PDFs, EPUBs) using advanced RAG (Retrieval-Augmented Generation) techniques. It features a modern, responsive UI, secure authentication, group collaboration, and subscription billing. ## Features - **🤖 AI Chat**: Intelligent chat interface powered by OpenAI and Vercel AI SDK. - **📚 Document Intelligence**: - Support for PDF and EPUB formats. - Automatic text extraction, chunking, and embedding generation. - Semantic search to retrieve relevant context for answers. - **📝 Annotations & Collaboration**: - Highlight and annotate documents. - Share documents and collaborate in groups. - Granular permission system (Owner, Viewer). - **🔐 Authentication**: Secure user authentication via Better Auth (Google OAuth, Email/Password). - **💳 Billing**: Integrated Stripe subscription management (Free vs Pro plans). - **👥 Groups**: Create groups to manage shared resources and team access. ## Tech Stack - **Framework**: [React Router v7](https://reactrouter.com/) (formerly Remix) - **Build Tool**: [Vite](https://vitejs.dev/) - **Styling**: [Tailwind CSS](https://tailwindcss.com/) - **Database**: [PostgreSQL](https://www.postgresql.org/) - **ORM**: [Drizzle ORM](https://orm.drizzle.team/) - **AI/LLM**: [Vercel AI SDK](https://sdk.vercel.ai/), OpenAI - **Storage**: [Supabase Storage](https://supabase.com/storage) - **Auth**: [Better Auth](https://better-auth.com/) - **Payments**: [Stripe](https://stripe.com/) ## Prerequisites - **Node.js**: v20+ recommended - **Bun**: (Optional) Used for faster package management and script execution. - **Docker**: (Optional) For running a local PostgreSQL instance. ## Environment Variables Create a `.env` file in the root directory with the following variables: ```env # Database DATABASE_URL="postgresql://user:password@localhost:5432/fractal_chat" # Authentication (Better Auth) BETTER_AUTH_SECRET="your_generated_secret" BETTER_AUTH_URL="http://localhost:5173" # or your production URL # OAuth Providers GOOGLE_CLIENT_ID="your_google_client_id" GOOGLE_CLIENT_SECRET="your_google_client_secret" # AI OPENAI_API_KEY="sk-..." # Storage (Supabase) SUPABASE_URL="https://your-project.supabase.co" SUPABASE_SERVICE_ROLE_KEY="your_service_role_key" SUPABASE_BUCKET="documents" # Default bucket for document storage # Payments (Stripe) STRIPE_SECRET_KEY="sk_test_..." STRIPE_PRICE_ID="price_..." # ID for the Pro subscription plan STRIPE_WEBHOOK_SECRET="whsec_..."