LLM Chatbot SaaS

A full-stack, web-based SaaS chatbot platform where users can chat with multiple open-source LLM models (Llama 7B, Qwen2 7B, 14B, 32B) powered by Ollama.

Features

• Multi-Model Support: Chat with Llama 2 (7B, 14B, 32B) and Qwen2 (7B), configurable via Ollama.
• Authentication:
  • Traditional Username & Password (JWT-based).
  • Passwordless Passkeys (WebAuthn) for highly secure, frictionless logins using device biometrics (Face ID, Touch ID, Windows Hello).
• Usage Tracking & Tiers:
  • Tracks monthly token usage per model group.
  • Supports Free and Paid subscription tiers with rate-limiting.
• Conversation History: Threaded chat management with a sidebar to navigate past conversations.
• Modern UI: Responsive, vanilla HTML/CSS/JS frontend with real-time token tracking.

Architecture

• Backend: Python 3, FastAPI, SQLAlchemy
• Frontend: Vanilla JavaScript, HTML5, CSS3
• Database: SQLite
• AI Engine: Ollama API

Setup Instructions

Prerequisites

1. Python 3.10+ installed.
2. Ollama installed and running on your machine (ollama serve).

1. Model Preparation

Pull the required models into your local Ollama instance:

ollama pull llama2:7b
ollama pull qwen2:7b
ollama pull llama2:14b
ollama pull llama2:32b

2. Backend Setup

Navigate to the backend directory and install dependencies:

cd chatbot-backend
python3 -m pip install -r requirements.txt
python3 -m pip install webauthn # For Passkeys

(Note: It is highly recommended to use a virtual environment python3 -m venv venv)

3. Running the Server

Start the FastAPI application:

cd chatbot-backend
uvicorn main:app --reload

The application will start on http://127.0.0.1:8000.

4. Accessing the App

Open your browser and navigate to http://localhost:8000. You will be greeted by the login screen where you can sign up using a password or a Passkey.

Project Structure

• chatbot-backend/main.py: Application entry point.
• chatbot-backend/routes/: FastAPI routers for /auth, /chat, /usage, and /webauthn.
• chatbot-backend/frontend/: Static HTML, CSS, and JS files served by FastAPI.
• chatbot-backend/database.py: SQLite SQLAlchemy models and connection setup.

Next Steps / Roadmap

• Stripe Integration for Paid Tiers (Spec defined).
• Password Reset Flow.
• Email Service Integration for notifications.