VT is a privacy-focused AI chat application delivering cutting-edge AI capabilities through a sophisticated dual-tier subscription system. Built with modern web technologies and a privacy-first architecture, VT offers advanced AI reasoning, document processing, web search integration, and comprehensive multi-AI provider support.

• Premium AI Models (Free with BYOK): Claude 4 Sonnet/Opus, GPT-4.1, O3/O3 Mini/O4 Mini, O1 Mini/Preview, Gemini 2.5 Pro, DeepSeek R1, Grok 3 - all available to logged-in users with their own API keys
• 9 Free AI Models: Gemini 2.0/2.5 Flash series + OpenRouter models (DeepSeek V3, Qwen3 14B)
• Multi-AI Provider Support: OpenAI, Anthropic, Google, Fireworks, Together AI, and xAI integration
• Intelligent Tool Router (Free): AI-powered semantic routing automatically activates the right tools based on your queries using OpenAI embeddings and pattern matching
• Document Processing (Free): Upload and analyze PDF, DOC, DOCX, TXT, MD files (up to 10MB) - available to all logged-in users
• Structured Output Extraction (Free): AI-powered JSON data extraction from documents - available to all logged-in users
• Chart Visualization (Free): Create interactive bar charts, line graphs, pie charts, and scatter plots - always available and discoverable through smart UI
• Thinking Mode (Free): Complete AI SDK reasoning tokens support with transparent thinking process - available to all logged-in users
• Mathematical Calculator (Free): Advanced functions including trigonometry, logarithms, and arithmetic - always available and discoverable through smart UI
• Web Search Integration (Free): Real-time web search capabilities for current information - always available and discoverable through smart UI

• Local-First Storage: All chat data stored in browser's IndexedDB via Dexie.js
• Zero Server Storage: Conversations never leave the user's device
• Multi-User Isolation: Complete data separation on shared devices
• Security: Secure authentication with Better Auth
• Privacy-Focused Security: Bot detection and secure authentication with Better Auth

• Free tier (logged-in users): ALL premium AI models (Claude 4, GPT-4.1, O3, etc.) + all advanced features - intelligent tool routing, chart visualization, dark mode, thinking mode, structured output, document parsing, reasoning chain, Gemini caching, web search, multi-modal chat, and unlimited BYOK usage
• VT+ ($5.99/month): Everything free + 3 exclusive research features: PRO_SEARCH (Enhanced Web Search), DEEP_RESEARCH (Deep Research capabilities), and RAG (Personal AI Assistant with Memory)
• Seamless Management: Creem.io integration with customer portal

• Shadcn UI Design System: Consistent, accessible interface
• Smart Tool Discovery: All tools always visible and clickable with intelligent gated access dialogs
• Seamless Feature Access: Tools remain enabled for discoverability while proper access controls show contextual dialogs
• Dark Mode: Premium theming experience for all logged-in users
• Responsive Design: Optimized for desktop and mobile
• 87% Performance Improvement: Faster compilation and load times

VT utilizes a Turborepo-managed monorepo structure:

vtchat/
├── apps/
│   └── web/              # Next.js 14 web application (App Router)
├── packages/
│   ├── actions/          # Server actions (e.g., feedback)
│   ├── ai/               # AI models, providers, tools, semantic router, workflow logic
│   ├── common/           # Shared React components, hooks, context, store
│   ├── orchestrator/     # Workflow engine and task management
│   ├── shared/           # Shared types, constants, configs, utils, logger
│   ├── tailwind-config/  # Shared Tailwind CSS configuration
│   ├── typescript-config/# Shared TypeScript configurations
│   └── ui/               # Base UI components (from Shadcn UI)
├── docs/                 # Documentation and guides
├── memory-bank/          # Project context and evolution tracking
└── scripts/              # Utility scripts (e.g., data sync)

• Framework: Next.js 14 (App Router) with TypeScript
• Styling: Tailwind CSS + Shadcn UI design system
• State Management: Zustand + React Query
• Animations: Framer Motion
• Icons: Lucide React

• Database: Neon PostgreSQL with Drizzle ORM
• Authentication: Better Auth (modern session management)
• Application Security: Bot detection for authentication and secure OAuth integration
• Payment Processing: Creem.io integration
• Local Storage: IndexedDB via Dexie.js
• Deployment: Fly.io (production-ready)

• Runtime: Bun (package manager + JavaScript runtime)
• Monorepo: Turborepo with optimized caching
• Testing: Vitest with Testing Library
• Code Quality: Biome (formatting & linting) + oxlint (comprehensive linting)
• Type Checking: TypeScript with strict configuration
• Performance Monitoring: React Scan for development performance optimization

• AI Providers: OpenAI, Anthropic, Google, Fireworks, Together AI, xAI
• AI SDK: Vercel AI SDK with reasoning tokens support
• Semantic Tool Router: OpenAI embeddings + pattern matching for intelligent tool activation
• Document Processing: Multi-format file analysis
• Chart Generation: Bar charts, line graphs, pie charts, scatter plots
• Web Search: Real-time grounding capabilities

• Bun (JavaScript runtime and package manager) - v1.1.19 or higher
• Node.js (for some Turborepo operations, though Bun is primary)
• Git for version control

1. Clone the repository:

   git clone https://github.com/vinhnx/vtchat.git
   cd vtchat

2. Install dependencies:

   bun install

3. Set up environment variables:

   cp apps/web/.env.example apps/web/.env.local

   Configure the following required variables in apps/web/.env.local:

   Essential Services:

   • DATABASE_URL - Neon PostgreSQL connection string
   • BETTER_AUTH_SECRET - Authentication secret key
   • BETTER_AUTH_URL - Authentication URL (process.env.NEXT_PUBLIC_BASE_URL for development)

   AI Provider Keys (choose one or more):

   • OPENAI_API_KEY - OpenAI API access
   • ANTHROPIC_API_KEY - Anthropic Claude API access
   • GOOGLE_API_KEY - Google Gemini API access

   Payment & Subscription:

   • CREEM_WEBHOOK_SECRET - Creem.io webhook validation
   • CREEM_API_KEY - Creem.io API access
   • CREEM_PRODUCT_ID - VT Plus subscription product ID

   Security:

   • NEXT_PUBLIC_BASE_URL - Application base URL

4. Set up the database:

   cd apps/web
   bun run generate  # Generate database schema

5. Start the development server:

   bun dev

6. Open the application: Navigate to process.env.NEXT_PUBLIC_BASE_URL in your browser.

# Development
bun dev                 # Start development server with Turbopack
bun build              # Build for production
bun start              # Start production server
bun test               # Run tests
bun test:coverage      # Run tests with coverage

# Code Quality
bun lint               # Lint with oxlint
bun run biome:format   # Format code with Biome
bun run biome:check    # Check code formatting with Biome

# Database
cd apps/web
bun run generate       # Generate Drizzle schema

The application requires several environment variables for full functionality. Refer to apps/web/.env.example for the complete list. Key configurations include:

• Database: Neon PostgreSQL for user data and subscriptions
• Authentication: Better Auth for secure session management
• AI Providers: Support for multiple AI APIs
• Payment: Creem.io for subscription management
• Security: Bot detection and secure authentication

VT is production-ready and deployed on Fly.io:

• URL: https://vtchat.io.vn
• Infrastructure: Fly.io with 2-region setup (Singapore primary, Virginia secondary)
• Performance: 87% faster compilation, optimized bundle size
• Security: Privacy-focused security with bot detection
• Monitoring: Comprehensive error tracking and performance monitoring

• Memory: 1GB RAM per instance
• CPU: 1 shared CPU
• Regions: Asia-Pacific (primary), USA East (secondary)
• Health Checks: HTTP and TCP monitoring
• Auto-scaling: Suspend/resume based on traffic

• Production Deployment Checklist: Comprehensive pre-deployment verification
• Production Monitoring Setup: Error tracking, performance monitoring, and alerting
• Final Release Notes: Complete feature summary and achievements
• Final Project Report: Comprehensive technical and business analysis

• AGENT.md: Development guidelines and conventions
• Security Guide: Security implementation and privacy features
• Subscription System: Plan management, caching, and Creem.io integration
• Customer Portal: User subscription management interface

The /memory-bank directory contains contextual documents tracking project evolution, feature implementations, and development insights for continuous improvement.

VT implements comprehensive security measures:

• Privacy-First: All conversations stored locally in IndexedDB
• Authentication: Better Auth with secure session management
• Application Security: Bot detection and secure authentication
• Rate Limiting: Prevents abuse with intelligent rate limiting
• Data Protection: No server-side storage of sensitive chat data
• Secure Communication: HTTPS enforced, secure headers implemented

VT includes comprehensive testing:

# Run all tests
bun test

# Run tests with UI
bun test:ui

# Run tests with coverage
bun test:coverage

# Run specific test suites
bun test app/tests/rate-limit-simple.test.ts

Testing framework: Vitest with Testing Library for React components.

We welcome contributions! Please follow these guidelines:

1. Fork the repository and create a feature branch
2. Follow the coding standards defined in AGENT.md
3. Write tests for new features
4. Update documentation as needed
5. Submit a pull request with a clear description

• Use TypeScript with strict configuration
• Follow the existing code style and patterns
• Ensure all tests pass before submitting
• Update AGENT.md with any significant changes

This project is licensed under the MIT License. See the LICENSE file for details.

• Zero TypeScript Errors: Complete type safety across the codebase
• 87% Performance Improvement: Optimized compilation and runtime
• Smart UX Design: All tools discoverable through always-enabled buttons with intelligent gated dialogs
• Production-Ready: Deployed and running in production environment
• Security Hardened: Comprehensive protection against common threats
• Privacy-First: Commited to user data protection

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