nano-banana

name

nano-banana

description

Generate images from text prompts or edit existing images using Google Gemini's Nano Banana Pro model. Use this skill whenever the user wants to create an image, generate a picture, make a visual, create artwork, design graphics, edit a photo, modify an image, update a picture, or add/remove/change elements in an image. Also trigger when the user says 'nano banana', 'generate an image', 'create a picture', 'make me an image', 'edit this image', 'modify this photo', mentions wanting a logo, icon, illustration, diagram rendered as an image, or references image generation or manipulation in any way - even casually like 'can you make a picture of...' or 'what would X look like'.

Nano Banana - Image Generation & Editing

Generate images from text or edit existing images using Google Gemini's Nano Banana models via REST API. No SDKs or pip installs required - just Python 3.6+ and a GEMINI_API_KEY in the environment.

Workflow

1. Clarify intent

Figure out whether the user wants to:

• Generate a new image from a text description
• Edit an existing image (they'll reference a file path or describe an image in the project)

2. Ask about quality

Before generating, confirm their preferences. Present these options conversationally - not as a form:

Setting	Options	Default
Aspect ratio	1:1 (square), 16:9 (landscape), 9:16 (portrait), 4:3, 3:4, 21:9 (ultrawide)	1:1
Image size	512 (draft/fast), 1K (standard), 2K (high quality), 4K (maximum detail)	2K
Model	Lite (default, great quality), Pro (maximum quality), or Flash (faster, lighter)	Lite

If the context makes the right choice obvious (e.g. a phone wallpaper is clearly 9:16), just confirm rather than asking. Skip the question entirely for quick/casual requests and use sensible defaults.

3. Generate

Run the helper script. It lives in scripts/gemini-image.py relative to this skill's directory.

Text-to-image:

python3 <this-skill-dir>/scripts/gemini-image.py \
  --prompt "detailed description of the image" \
  --output "descriptive-filename.png" \
  --aspect "1:1" \
  --size "2K"

Edit an existing image:

python3 <this-skill-dir>/scripts/gemini-image.py \
  --prompt "what to change about the image" \
  --input "path/to/source.png" \
  --output "edited-version.png" \
  --aspect "1:1" \
  --size "2K"

Output files go in the user's current working directory (or wherever they specify).

4. Show the result

After the script runs, read the output image file and show it to the user. If they want changes, run another edit pass using the generated image as --input.

Models

Model	Flag	Best for
Nano Banana Lite	--model gemini-3-lite-image-preview (default)	Great quality, balanced speed and detail
Nano Banana Pro	--model gemini-3-pro-image-preview	Maximum quality, complex scenes, text in images
Nano Banana Flash	--model gemini-3.1-flash-image-preview	Speed, high-volume, quick iterations

Prompt tips

• Be specific: mention style, lighting, composition, colors, mood
• For edits, describe what should change and what should stay the same
• The model handles text rendering well - include exact text you want in the image
• Reference art styles, time periods, or visual aesthetics for more control
• For iterative refinement, use the previous output as --input with a refinement prompt

Requirements

• NANO_BANANA_API_KEY environment variable
• Python 3.6+ (stdlib only, no dependencies)