AI Chatbot

A web-based AI chatbot powered by Google Gemini 2.5 Flash, built with Node.js and Express. Supports multiple conversations, chat history, and a clean browser UI.

Features

• Real-time AI responses via Google Gemini
• Multiple conversations with persistent history
• Auto-generated chat titles from the first message
• Rename and delete conversations
• Guest sessions (no login required)
• Rate-limit retry handling
• Markdown rendering in responses

Project Structure

chatbot/
├── server.js          # Express server & API routes
├── package.json
├── .env               # API keys (not committed)
├── public/
│   ├── index.html
│   ├── chat.html      # Main chat UI
│   ├── css/
│   │   └── style.css
│   └── js/
│       ├── auth.js
│       └── chat.js
└── data/
    ├── users.json     # User data
    └── chats/         # Per-user conversation files

Getting Started

1. Install dependencies

npm install

2. Configure environment variables

Create a .env file in the project root:

GEMINI_API_KEY=your_gemini_api_key_here
SESSION_SECRET=your_session_secret_here
PORT=3000

Get a free Gemini API key at https://aistudio.google.com/app/apikey.

3. Start the server

npm start

Open http://localhost:3000 in your browser.

API Endpoints

Method	Endpoint	Description
GET	/api/auth/me	Get current session user
GET	/api/chat/history	List all conversations
POST	/api/chat/new	Create a new conversation
GET	/api/chat/:id	Get a conversation with messages
POST	/api/chat/send	Send a message and get AI response
PUT	/api/chat/:id/rename	Rename a conversation
DELETE	/api/chat/:id	Delete a conversation

Dependencies

• express — Web framework
• @google/generative-ai — Gemini API client
• express-session — Session management
• uuid — Unique ID generation
• dotenv — Environment variable loading
• bcryptjs — Password hashing
• marked — Markdown rendering