If you post car content on Instagram, you know the pain of writing fresh captions every time. I built an AI-powered caption generator that helps you auto-generate captions, hashtags, and even TikTok sound ideas — just from a car photo.

In this article, I’ll show you how I built it using:

• 🧠 OpenAI GPT-4 Vision
• 🖼️ Image analysis
• 🌐 Streamlit app interface
• 🛠️ My personal caption history as training context

🔧 What We'll Build

🚀 Tech Stack

• Streamlit – for the UI
• OpenAI GPT-4 Vision – to understand car photos
• Python (with openai, streamlit, dotenv)

📁 Project Structure

car-caption-generator-ai/
├── app.py                     # Streamlit app logic
├── utils/
│   ├── vision.py              # GPT-4 Vision logic
│   ├── captions.py            # Captions and hashtags generator
│   └── prompts.py             # Stores the prompt template
├── requirements.txt           # Dependencies
└── README.md

Setup Instructions

1 .Clone the repo:

git clone https://github.com/Navashub/caption_generator_ai.git
cd car-caption-generator-ai

2.Create and activate a virtual environment:

python -m venv myvenv
source myvenv/bin/activate  # Windows: myvenv\Scripts\activate

3.Install dependencies:

pip install -r requirements.txt

4.Add your OpenAI API key in a .env file

OPENAI_API_KEY=""

5.Run the app:

streamlit run app.py

🧠 How It Works

1.The app uses GPT-4 Vision to describe your uploaded car image.
2.That description is passed into a prompt template (along with your past captions).
3.The model returns:
- An Instagram caption
- Hashtags
- TikTok sound vibes

Here’s a sample output for an Audi RS5:

"Brutal beauty in carbon black. The RS5 doesn’t speak — it growls. Welcome to the autobahn attitude. 💨🔥
#RS5Power #FavouriteFourRings #AudiLife"