NexBook AI | Voice Booking React Native App

NexBook AI — Voice Booking React Native App

NexBook AI is a production-ready, commercial-grade appointment booking ecosystem designed for modern salons, luxury spas, wellness centers, barbershops, and aesthetic clinics. The complete platform unites an autonomous conversational AI Voice Booking Agent (@ai-agent), a high-performance React Native Customer Mobile App (built on the latest Expo SDK), an interactive Super Admin Web Portal & Real-Time POS Register (React 19 / Vite / Tailwind CSS v4), and a centralized Node.js Express TypeScript REST API with live Socket.io bi-directional synchronization, Stripe PaymentSheet integration, and automated push notifications.

⭐ Key Highlights & Commercial USPs

• ️ Autonomous Conversational Voice AI Concierge: Multi-turn spoken booking agent powered by Groq Cloud (openai/gpt-oss-120b) and LangGraph. Automatically extracts services, specialists, dates, and times from natural voice speech and prepares bookings in under 15 seconds.
• Interactive Real-Time POS Register & Walk-In Billing: Dedicated Point of Sale terminal for front-desk staff to handle walk-ins, apply custom percentage or fixed discounts, select specialists, take split cash/card payments, and generate 80mm thermal receipts.
• Stripe Payment Gateway & Native Mobile PaymentSheet: Full support for online prepayments, 25% booking deposits, Apple Pay, Google Pay, card elements, and cryptographic signature-verified Stripe webhook listeners.
• Multi-Channel Push & In-App Notifications: Real-time Expo push notifications sent directly to customer devices on booking confirmation, status changes, and payment completions, accompanied by live Socket.io admin sound alerts and HTML email receipts.
• Staff Roster, Shift & Vacation Leave Management: Configure specialist working hours, buffer times between treatments, and manage staff leave requests with automatic live calendar blocker enforcement.
• Universal React Native Mobile Experience: Built with the latest Expo SDK and NativeWind / Tailwind CSS v5, featuring animated bottom sheets, haptic feedback, service search filters, and digital QR appointment check-in passes.
• ️ Pre-LLM Security Guardrail Shield: Built-in input shield that blocks prompt injections, jailbreaks, gibberish, and off-domain chatter before reaching LLMs — saving 100% token costs on non-booking interactions.
• Executive Revenue Analytics & Financial Reporting: Live financial metrics including Gross Revenue, Completed Bookings, Specialist Performance Metrics, and downloadable CSV invoice reports.
• Zero-Code Dynamic Rebranding: Salon administrators can dynamically upload custom business logos and favicons stored on Cloudinary CDN directly via the Admin Dashboard without rebuilding or redeploying code.

Live Demo & Test Credentials (Try & Test)

• Live Admin & POS Web Demo: Launch Live Admin Web Dashboard
• Customer Mobile App (Android APK): Download User App APK (Google Drive)
• Super Administrator: Email: sa1506758@gmail.com | Password: 123456
• Customer Client Demo: Email: shakeelsoftwaredev@gmail.com | Password: 123456

⚠️ External Services & Upfront Cost Disclosures

IMPORTANT NOTICE TO BUYERS: NexBook AI 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 generous free tiers are available for setup and testing, commercial 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 transaction (rates vary by region 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 hosting service catalog images, staff profile avatars, and salon branding logos. It includes a free tier (25 monthly credits, approx. 25GB storage/bandwidth). High-volume media uploads will require a paid plan (starting at $19/month).
• MongoDB Atlas Database (Free Sandbox with Paid Tiers): MongoDB Atlas hosts your cloud database. It includes a permanent free M0 sandbox cluster (512MB storage), ideal for testing. Production deployments with large client records will require a paid cluster (starting at ~$9 to $57/month).
• ⚡ Groq Cloud AI (Free Developer Tier Available): Groq provides free developer quotas for ultra-fast LLM inference (openai/gpt-oss-120b). Commercial high-concurrency voice traffic may require paid API token usage.
• Firebase & Firebase Cloud Messaging (FCM) (Free Spark Plan): Firebase Cloud Messaging (FCM) and Expo Push Notifications provide 100% free unlimited push notification delivery under the standard Firebase Spark tier with zero ongoing message fees. Advanced optional Google Cloud / Firebase Blaze usage (e.g. high-volume Phone SMS verification) is billed pay-as-you-go.
• Expo Push Notification Service (Free): Push notifications are delivered via Expo Server SDK with no per-message fees.
• ✉️ Nodemailer SMTP Email Service: Supports free Gmail App Passwords, SendGrid, Mailgun, and AWS SES. Includes a local development console simulator for testing without SMTP credentials.

Autonomous AI Agent Stack & Architecture (@ai-agent)

NexBook AI features an enterprise-grade, stateful conversational booking agent engineered using LangChain, LangGraph, and Groq Cloud for lightning-fast sub-second voice interactions:

• ⚡ Inference Engine & Speech-to-Text: Powered by Groq Cloud (openai/gpt-oss-120b) and Groq Whisper audio transcription (/api/v1/ai/voice/transcribe) for near-instantaneous spoken dialogue.
• Compiled LangGraph 6-Node Workflow: Operates as a stateful cyclic state machine coordinating 6 specialized execution nodes:
  • classifyIntent: Natural Language Understanding (NLU) extracting requested services, specialists, dates, 24h normalized times, and add-on treatments with automatic language detection.
  • queryDatabase: Real-time MongoDB catalog search and dynamic slot availability calculation accounting for specialist working shifts, buffer times, and approved vacations.
  • executeBooking: Atomic, double-booking collision-free reservation creation with tax and add-on price computation.
  • cancelBooking: Secure cancellation tool enforcing authenticated customer scoping and booking reference verification.
  • rescheduleBooking: Conflict-checked appointment shifting within transactional MongoDB sessions.
  • generateResponse: Empathetic response generation with speech properties (rate, pitch, language), suggested quick-action chips, and pronunciation safety filters.
• Stateful Multi-Turn Session Memory: In-memory session store with TTL auto-expiry and MongoDB write-through persistence that remembers draft parameters (services, dates, times, specialists, extras) across multi-turn voice conversations.
• ️ Pronunciation-Safe Speech Synthesis: Automatically removes hyphens before price amounts to ensure client text-to-speech engines never vocalize ”$185” as “minus 185 dollars”.

️ Enterprise Protected Guardrail & Input Shield (GuardrailService)

To ensure bulletproof operational security and protect buyers against runaway API token bills, NexBook AI includes a comprehensive Pre-LLM Input Guardrail Shield that inspects every spoken transcript before it reaches the AI inference engine:

• Prompt Injection & Jailbreak Interceptor: Blocks malicious prompt injection attacks, system prompt extraction attempts, DAN modes, roleplay overrides, and raw instruction delimiter injections (e.g., <|im_start|>, [INST]).
• Out-of-Domain Topic Deflection: Automatically intercepts and deflects unrelated queries (programming requests, essay writing, calculus, cryptocurrency trading, politics) with polite fallback guidance — saving 100% token costs on non-booking interactions.
• ⚡ Zero-Token Fast-Path Greetings: Common conversational greetings (“hi”, “hello”, “who are you”, “help”) are served instantly in sub-5ms from pre-compiled response templates without burning any LLM tokens.
• Spam, Mashing & Gibberish Filtering: Real-time heuristic filters detect repetitive character sequences, keyboard mashing, vowel-less spam, and oversized inputs before execution.
• Horizontal Access Control & Data Isolation: AI tools strictly enforce customer: userId scoping across all lookups to guarantee users can only view, reschedule, or cancel their own bookings.

Security Architecture: All AI calls route securely through the centralized Node.js backend proxy. API credentials remain strictly confidential on the server in backend/.env and are never exposed to mobile or web clients.

Included Modules & Codebase Architecture

1. Customer Mobile App (React Native / latest Expo SDK / TypeScript / NativeWind Tailwind)

• Voice AI Concierge Screen: Real-time voice recording, animated speech waveforms, conversation transcripts, and instant booking summary cards.
• Explore & Category Filters: Browse treatments by category (Hair Styling, Facial & Skincare, Massage & Body, Nails, Beard & Shave), search by keyword, and view popular services.
• Service Detail & Add-on Selector: Rich service previews, duration badges, price breakdown, and multi-select add-on checkboxes with dynamic total calculation.
• Specialist Selection & Time Slot Picker: View staff specialties, review ratings, select available dates, and browse dynamic morning/afternoon time pills.
• Native Stripe PaymentSheet: In-app checkout supporting full payment or 25% deposit via credit/debit cards, Apple Pay, and Google Pay.
• My Bookings & Digital QR Pass: Tabbed views for Upcoming, Completed, and Cancelled appointments with scannable QR verification passes.
• Push & In-App Notification Center: Real-time alerts on booking confirmation, specialist assignment, and payment status.
• Profile & Account Settings: Edit personal details, manage saved payment methods, toggle notifications, and switch themes.

2. Admin Web Portal & POS (React 19 / Vite / TypeScript / Tailwind CSS v4)

• Executive Dashboard: Real-time overview of daily revenue, appointment counts, active specialists, and live Socket.io booking feeds.
• Appointments Management (Table & Kanban): Filter appointments by date and status, update booking states (Confirmed, In Progress, Completed, Cancelled), and view customer notes.
• Point of Sale (POS) Terminal: Rapid walk-in checkout with client search/creation, custom discounts, cash/card tender, and 80mm thermal receipt printing.
• Service & Category Manager: Create, edit, and categorize services with custom pricing, durations, buffer times, and optional add-on extras.
• Staff & Schedule Management: Manage specialist profiles, working hours, shift assignments, and review/approve vacation leave requests.
• Customer Directory & History: Complete client CRM with total spend, booking history, contact details, and direct account management.
• Financial Analytics & Reports: Revenue breakdown charts, payment logs, refund processing, and one-click CSV export.
• Business Profile & Customization: Configure salon working hours, contact info, social links, and upload brand logos dynamically to Cloudinary CDN.

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

• Stateful LangGraph AI Voice Engine: 6-node compiled workflow with entity extraction, live slot query tools, and atomic booking actions.
• Authentication & RBAC: Bcrypt password hashing (12 salt rounds), strict JWT access & refresh token rotation, and role-based guards (Admin, Staff, Customer).
• Stripe Payment Engine: PaymentIntent creation, Hosted Checkout sessions, refund processing, and signature-verified webhook handlers.
• Real-Time Socket.io Gateway: Bi-directional event broadcasting for instant appointment updates, payment alerts, and audio notifications.
• Expo Push Notification Dispatcher: Automated push notification delivery via Expo Server SDK with rich payload metadata.
• Nodemailer SMTP Transporter: Responsive branded HTML email templates for booking confirmations, staff alerts, and payment receipts.
• Mongoose ODM Database Models: Robust schemas for Users, Services, Categories, Staff, Bookings, Payments, Notifications, and VoiceSessions.

What You Get (Download Package Contents)

• Complete Customer Mobile App Source Code (userapp/): Full React Native / Expo project ready for iOS & Android EAS builds.
• Complete Admin Web Portal & POS Source Code (frontend/): Full React 19 / Vite / Tailwind CSS v4 codebase.
• ⚙️ Complete Centralized Backend REST API (backend/): Full Node.js / Express / TypeScript backend with LangGraph AI engine.
• Comprehensive Interactive Documentation (documentation/index.html): Searchable HTML guide including non-technical tutorials, step-by-step EAS APK build commands, full REST API reference, and troubleshooting guides.
• Database Seeders & Environment Templates: Ready-to-use seed scripts with realistic demo services, specialists, and appointments.
• Free Lifetime Updates: Access to all future feature releases, framework updates, and compatibility patches.

⚙️ Technical Specifications & Compatibility

• Software Version: v1.0.0 (Initial Commercial Release)
• Mobile Stack: React Native, latest Expo SDK, Expo Router, NativeWind Tailwind CSS v5
• Web Admin Stack: React 19, Vite, TypeScript, Tailwind CSS v4, Lucide Icons
• Backend Stack: Node.js (v18.0.0+ / v20+ recommended), Express.js, TypeScript, Mongoose ODM
• AI Inference: LangChain LangGraph, Groq Cloud (openai/gpt-oss-120b)
• Database: MongoDB v6.0+ (Local) or MongoDB Atlas Cloud Cluster
• Supported Mobile Platforms: iOS 13+ (iPhone / iPad), Android 8.0+ (Oreo to Android 15+)
• Supported Desktop Browsers: Google Chrome, Mozilla Firefox, Apple Safari, Microsoft Edge, Opera

Support & Contact

If you have any questions, require setup guidance, or need custom development services, feel free to reach out:

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