Nano Banana 2 — Prompt Library & Image Generator

The only repo that combines a Nano Banana 2 prompting guide, Gemini Flash prompt auto-generation, and a Claude Code skill in one end-to-end pipeline.

Write plain-English ideas → Gemini writes expert Nano Banana 2 prompts → Hypereal generates 4K images. No prompt engineering knowledge required.

How It Works

1. Write plain-English image ideas in concepts.txt (one per line)
2. Run /hypereal-images in Claude Code
3. Gemini Flash reads your ideas and writes optimized Nano Banana 2 prompts
4. Hypereal API generates the images at 4K resolution
5. Images download automatically to your output/ folder

What Makes This Different

Most repos have either an API wrapper or a prompt collection. This combines:

• A curated Nano Banana 2 prompting knowledge base (knowledge/nano_banana_prompting.md)
• Automatic prompt generation via Gemini Flash from plain-English concepts
• A Claude Code skill (/hypereal-images) that orchestrates the whole pipeline

What You Need

1. A Hypereal account (affiliate link*)
Sign up at https://hypereal.tech?ref=2mWwuWId -- pay-as-you-go credit system, no subscription required. Buy credits as needed: 8 credits per 4K image, 4 credits per 2K image.

* Affiliate link -- if you sign up through this link, we may earn a small commission at no extra cost to you.

2. A Gemini API key
Go to https://aistudio.google.com, click Get API key. Costs $0.002 per prompt ($0.02 for 10 images). You pay Google directly -- no subscription needed.

3. Claude Code
Download from https://claude.ai/claude-code. Run claude in your terminal to open it.

4. Python 3.10 or newer
Check: python --version. Install from https://python.org if needed.

Setup -- Step by Step

Step 1 -- Get the Package

Option A -- Download ZIP:
Download from the releases page and unzip:

• Windows: C:\Users\YourName\Documents\nano-banana-prompts\
• Mac/Linux: ~/Documents/nano-banana-prompts/

Option B -- Clone from GitHub (recommended):

git clone https://github.com/YOUR_USERNAME/nano-banana-prompts
cd nano-banana-prompts

Step 2 -- Install Python Packages

pip install google-genai aiohttp python-dotenv

If pip is not found, try pip3 or python -m pip install google-genai aiohttp python-dotenv.

Step 3 -- Get Your Hypereal API Key (affiliate link*)

1. Sign up or log in at https://hypereal.tech?ref=2mWwuWId
2. Go to Account Settings -> API Keys
3. Copy your key (looks like: ck_abc123...)
4. Buy credits as needed -- no subscription required

* Affiliate link -- we may earn a small commission at no extra cost to you.

Step 4 -- Get Your Gemini API Key

1. Go to https://aistudio.google.com
2. Click Get API key -> Create API key
3. Copy the key (looks like: AIzaSy...)
4. Make sure billing is enabled -- costs ~$0.002 per prompt

Step 5 -- Configure Your API Keys

Copy the example env file and add your keys:

cp .env.example .env

Open .env in any text editor and paste your keys:

HYPEREAL_API_KEY=ck_your_hypereal_key_here
GEMINI_API_KEY=AIzaSy_your_gemini_key_here

Save the file. Never share it or commit it -- it is in .gitignore.

Step 6 -- Install the Skill into Claude Code

Option A -- Copy manually:

Windows (PowerShell):

New-Item -ItemType Directory -Force "$env:USERPROFILE\.claude\skills\hypereal-images"
Copy-Item SKILL.md "$env:USERPROFILE\.claude\skills\hypereal-images\SKILL.md"

Mac / Linux:

mkdir -p ~/.claude/skills/hypereal-images
cp SKILL.md ~/.claude/skills/hypereal-images/SKILL.md

Option B -- Symlink from cloned repo (GitHub users):

Mac / Linux -- git pull will auto-update your skill:

mkdir -p ~/.claude/skills/hypereal-images
ln -s "$(pwd)/SKILL.md" ~/.claude/skills/hypereal-images/SKILL.md

Step 7 -- Add Your Image Ideas to concepts.txt

Open concepts.txt and write your ideas -- one per line:

A woman working at a laptop in a modern cafe, warm morning light
Mountain summit at golden hour with dramatic storm clouds
Abstract geometric neon pattern on deep black background

Lines starting with # are comments and are ignored.

Step 8 -- Open Claude Code and Generate

Navigate to the folder and launch Claude Code:

cd ~/Documents/nano-banana-prompts
claude

Then type:

/hypereal-images

Claude will check your keys, show your concepts, ask for aspect ratio/style/resolution, write the prompts via Gemini, and generate all images. About 3-5 minutes for 5 images at 4K.

Cost Breakdown

Example: 10 images at 4K = 80 Hypereal credits + ~$0.02 in Gemini costs.

Advanced Usage

python generate_prompts.py --force                  # Rewrite all prompts
python generate_prompts.py --style photorealistic   # Force photorealistic track
python generate_prompts.py --aspect-ratio 9:16      # Vertical/wallpaper format
python generate_images.py --dry-run                 # Preview without spending credits
python generate_images.py --resolution 2K           # Half the credits
python generate_images.py --format png              # PNG instead of JPEG

Troubleshooting

"GEMINI_API_KEY not set" -- Run cp .env.example .env then add your Gemini key
"HYPEREAL_API_KEY not set" -- Add your Hypereal key to .env
"Invalid API key" -- Copy the key fresh from your Hypereal dashboard
"Out of credits" -- Top up at https://hypereal.tech?ref=2mWwuWId
"/hypereal-images not found" -- Repeat Step 6, copy SKILL.md to the skills folder

File Reference

nano-banana-prompts/
├── generate_prompts.py         Calls Gemini Flash to write prompts from concepts.txt
├── generate_images.py          Calls Hypereal API and downloads images
├── concepts.txt                Your image ideas -- edit this file
├── knowledge/
│   └── nano_banana_prompting.md    Nano Banana 2 prompt engineering guide
├── .env.example                API key template -- copy to .env and fill in your keys
├── .gitignore                  Keeps your .env and output/ out of git
├── SKILL.md                    Claude Code skill -- copy to ~/.claude/skills/
├── Getting Started Guide.pdf   Step-by-step setup guide with all links
├── README.md                   This file
├── prompts.json                Created automatically when you generate prompts
└── output/                     Generated images saved here (created automatically)

Affiliate Disclosure

The Hypereal links in this repo (https://hypereal.tech?ref=2mWwuWId) are affiliate links. If you sign up through them, we may earn a small commission at no extra cost to you. We only recommend products we genuinely use. The Gemini link is not an affiliate link -- we receive no commission from it.

Powered by

• Hypereal AI (https://hypereal.tech?ref=2mWwuWId) -- Nano Banana 2 T2I model, pay-as-you-go credits (affiliate link)
• Gemini Flash (https://aistudio.google.com) -- Prompt engineering (~$0.002/prompt)
• Claude Code (https://claude.ai/claude-code) -- Orchestration and workflow