🧠 Local ChatGPT-Style App with Ollama (Gemma 2B)

A full-stack ChatGPT-style app that runs locally using open-source LLMs via Ollama, built with Next.js, Node.js, Prisma, and PostgreSQL.

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🚀 Features

• ✅ ChatGPT-style UI with streaming response
• ✅ Chat history stored in PostgreSQL
• ✅ "New Chat", auto-title, and session view
• ✅ Ollama integration with gemma:2b model
• ✅ Interrupt generation with "Stop" button
• ✅ Clean, minimal UI with Tailwind CSS
• ✅ Local-only setup (no external APIs)

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🧱 Tech Stack

Layer	Technology
Frontend	Next.js + React + Tailwind CSS
Backend	Node.js + Express
LLM	Ollama with gemma:2b
Database	PostgreSQL (via Prisma)
ORM	Prisma ORM
Styling	Tailwind CSS

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📁 Project Structure

project/
├── app/                 # Next.js App Router
├── backend/             # Node.js + Express backend
├── components/          # React components
├── prisma/              # Prisma schema & migrations
├── .env                 # Environment config
├── package.json         # Scripts & dependencies

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⚙️ Setup Instructions

1. Clone the Repo

git clone <your-repo-url>
cd project

2. Install Dependencies

npm install

3. Setup PostgreSQL

Make sure PostgreSQL is installed and running on your system.

Create a new database:

CREATE DATABASE localchat;

Update your .env:

DATABASE_URL="postgresql://postgres:<your_password>@localhost:5432/localchat"

4. Run Prisma Migrations

npx prisma generate
npx prisma migrate dev --name init

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🧠 Run Ollama (Gemma 2B)

Make sure Ollama is installed. Then run:

ollama run gemma:2b

If not installed, get it here: https://ollama.com/download

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▶️ Start the App

npm run dev

• Frontend: http://localhost:3000
• Backend API: http://localhost:3001
• Database: PostgreSQL (view via pgAdmin)

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🧪 Development Tips

• Chats and messages are stored persistently in PostgreSQL
• You don’t need to rerun prisma migrate unless the schema changes
• PostgreSQL runs as a service: only start manually if it doesn’t auto-start
• Use pgAdmin to view or query tables (Chat, Message)

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🐛 Known Issues

• Ollama startup may be slow the first time
• Stream interruption ("Stop" button) works only mid-generation

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📸 Screenshots

Chat UI, Sidebar, and History stored in PostgreSQL via Prisma.

Screen.Recording.2025-07-30.003433.mp4

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📦 Credits

• Gemma Model by Google
• Ollama
• Next.js
• Prisma

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📄 License

MIT License