GPT-5 Nano Chat UI (Flask)

Simple local website with a chat interface connected to OpenAI gpt-5-nano.

1) Install dependencies

python3 -m venv .venv
source .venv/bin/activate
pip install -r requirements.txt

2) Configure environment

cp .env.example .env

Then set your key in .env:

OPENAI_API_KEY=your_real_key_here
PORT=3000

3) Run

python app.py

Open http://localhost:3000.

Notes

• API key stays server-side (app.py) and is never exposed in browser code.
• Frontend is plain HTML/CSS/JS in templates/ and static/.
• Press Enter to send, Shift+Enter for a new line.