NyxAI

NyxAI - An integrated chat platform with multiple AI models, where users can switch between models, create new chats, organize conversations, and compare responses.

Overview

NyxAI is a complete SaaS application built as a monorepo. The web app is built with Next.js (App Router) and talks to a dedicated Hono API backend. Authentication is handled with Google OAuth and JWT, with a BFF layer (Next.js Route Handlers) that stores the JWT in an httpOnly cookie and proxies authenticated requests to the API.

This repo contains 3 apps:

• backend/: Hono API + Drizzle ORM
• web/: Next.js app + BFF (web/app/api/*)
• native/: Expo app

Key Features

• Multiple AI Models: Access to GPT-5, Gemini 2.5, Claude 4 Sonnet, and DeepSeek V3
• Integrated Web Search: Ability to search for up-to-date information on the web during conversations
• Authentication: Google OAuth + JWT (httpOnly cookie) via Next.js BFF route handlers
• Subscription System: Stripe integration for Pro plans with custom limits
• Usage Control: Detailed monitoring of daily, weekly, and monthly usage
• Real-Time Chat: Streaming interface with markdown and syntax highlighting support
• Responsive Design: Interface optimized for desktop and mobile
• Dark/Light Theme: Full theme support with next-themes
• Sharing: Public conversation sharing system
• History: Complete navigation through conversation history

Technical Architecture

Main Stack

• Frontend: Next.js 16 with App Router, React 19, TypeScript
• Styling: Tailwind CSS 4 with Radix UI components
• BFF Layer: Next.js Route Handlers (web/app/api/*) proxying to the API
• Backend: Hono.js + Drizzle ORM (PostgreSQL)
• Database: PostgreSQL with Drizzle ORM
• Auth: Google OAuth (openid-client) + JWT
• Payments: Stripe for subscriptions and billing
• AI: AISDK + OpenRouter for unified model access
• Deploy: Optimized for Vercel (web) + any Bun host (API)

Project Structure

nyxai/
├── backend/                      # Hono.js API (Drizzle ORM)
│   ├── api/                      # Entry point
│   ├── src/
│   │   ├── db/                   # Drizzle schema
│   │   ├── routes/               # Hono routes
│   │   ├── services/             # Domain services
│   │   └── repositories/         # Drizzle repositories
├── web/                          # Next.js 16 app
│   ├── app/                      # App Router
│   │   └── api/                  # BFF Route Handlers (proxy to backend)
│   ├── components/               # UI
│   ├── data/                     # Client-side services (fetch to BFF)
│   └── server/                   # Server helpers/services used by app
└── native/                       # Mobile app

Setup and Installation

Prerequisites

• Bun (recommended)
• Node.js LTS (required by some Expo commands)
• PostgreSQL (for backend)
• Configured accounts: OpenRouter, Stripe, Google OAuth

Quickstart (local)

1. Backend env
   • Copy backend/.env.example to backend/.env
   • Fill required variables (see below)
2. Web env
   • Create web/.env.local (see below)
3. Install deps
   • backend/: bun install
   • web/: bun install
   • native/ (optional): bun install
4. Database (backend/)
   • bun run db:generate
   • bun run db:migrate:prod
5. Run
   • Terminal 1 (backend/): bun run dev
   • Terminal 2 (web/): bun run dev
   • Optional (native/): bun run start

Environment Variables

This repo has two runtime apps (web + backend). Each one has its own environment file.

Backend (backend/.env)

Copy from backend/.env.example and fill:

# Server
NODE_ENV=development
PORT=3001
API_URL=http://localhost:3001
WEB_URL=http://localhost:3000

# Database
DATABASE_URL="postgresql://..."

# Auth
JWT_SECRET="your-secret-key"
GOOGLE_CLIENT_ID="your-google-client-id"
GOOGLE_CLIENT_SECRET="your-google-client-secret"

# AI
OPENROUTER_API_KEY="your-openrouter-key"

# Payments
STRIPE_SECRET_KEY="sk_..."
STRIPE_PUBLISHABLE_KEY="pk_..."
STRIPE_WEBHOOK_SECRET="whsec_..."
STRIPE_PRICE_PRO_MONTHLY="price_..."
STRIPE_PRICE_PRO_YEARLY="price_..."

Stripe webhook endpoint (configure in Stripe Dashboard):

POST {API_URL}/api/webhooks/stripe

Web (web/.env.local)

NEXT_PUBLIC_API_URL=http://localhost:3001
NEXT_PUBLIC_STRIPE_PUBLISHABLE_KEY="pk_..."

Notes:

• NEXT_PUBLIC_API_URL is used by the BFF helpers to call the backend.
• NEXT_PUBLIC_STRIPE_PUBLISHABLE_KEY is required for the upgrade checkout.

Installation

# Install deps (each app has its own package.json)

cd backend && bun install
cd ../web && bun install
cd ../native && bun install

Database

Run migrations from backend/:

cd backend
bun run db:migrate

Running locally

In one terminal:

cd backend
bun run dev

In another terminal:

cd web
bun run dev

Optional (mobile):

cd native
bun run start

Access:

• Web: http://localhost:3000
• API: http://localhost:3001

Package managers and runtimes

Current state

• Backend runtime: Bun
• Backend package manager: Bun (bun.lockb)
• Web package manager: Bun (bun.lockb)
• Native package manager: Bun (bun.lockb)

Expo + EAS

• Expo and EAS support Bun as a package manager.
• EAS selects Bun when bun.lockb exists in native/.
• Keep Node.js LTS installed locally for some Expo commands.

If you want to pin a Bun version on EAS, configure it in native/eas.json.

References:

• https://expo.dev/changelog/2023-09-25-eas-bun-support
• https://docs.expo.dev/guides/using-bun/

Available Scripts

# web/
bun run dev
bun run build
bun run start

# backend/
bun run dev
bun run build
bun run start
bun run db:generate
bun run db:migrate:prod

# native/
bun run start
bun run android
bun run ios

Each app has its own scripts under backend/, web/, and native/.

Troubleshooting

Windows: node_modules delete fails (Access denied)

If you get file lock errors removing node_modules (common with Next.js native binaries), stop any running dev servers, close any processes that might hold locks, then retry deletion.

Expo + Bun prerequisites

Expo docs note that Node.js LTS is still required for some Bun-driven Expo commands because they use npm pack to download templates.

Bun: blocked postinstall scripts

If Bun blocks a postinstall script during bun install, list untrusted packages and allow them if appropriate:

bun pm untrusted

Stripe webhooks (local)

The backend expects Stripe webhooks at:

POST {API_URL}/api/webhooks/stripe

For local development, forward events to your machine using the Stripe CLI and set STRIPE_WEBHOOK_SECRET accordingly.

Data Model

Main Entities

• User: Users with authentication and profiles
• Chat: Conversations with titles and metadata
• Message: Individual messages with JSON content
• Subscription: Stripe subscriptions with Pro plans
• UserUsage: Usage limit control by period

Usage Limits (Pro Plan)

• Daily: 50 prompts
• Weekly: 250 prompts
• Monthly: 1000 prompts

Deployment

Vercel (Recommended)

1. Connect the repository to Vercel
2. Configure environment variables
3. Deployment will be automatic with each push

Other Platforms

The application is compatible with any platform that supports Next.js:

• Railway
• Render
• AWS Amplify
• Netlify (with adaptations)

Security

• Authentication: JWT stored in httpOnly cookie by Next.js BFF callback
• Authorization: API validates JWT on protected routes
• Rate Limiting: Subscription-based usage control
• Validation: Zod for data validation
• CORS: Allowlist origin configuration in the API

Performance

• Server Components: Optimized server-side rendering
• Streaming: Real-time AI responses
• Caching: Intelligent route and data caching
• Code Splitting: On-demand loading
• Image Optimization: Automatic image optimization

License

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

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