nanobanana

name	nanobanana
description	Use when the user asks to generate or edit images with Nano Banana, Gemini image models, `gemini-3.1-flash-image-preview`, `gemini-3-pro-image-preview`, or says things like “用 Gemini 出图”, “用 Nano Banana 生成图片”, “改图”, “多张变体”, “海报/插画/图标”. Prefer the bundled CLI at `scripts/nanobanana.py` instead of ad-hoc requests.
license	MIT
metadata	{"version":"1.0.1"}

Nano Banana Skill

Use this skill for Gemini image generation and lightweight image editing through Nano Banana models.

When to use

• The user explicitly mentions nanobanana, Nano Banana, Gemini image generation, or a Gemini image model name
• The user wants to generate one or more images from a prompt
• The user wants to generate images based on one or more reference images
• The user wants to edit an existing image with a text instruction

Workflow

1. Decide whether this is generate or edit.
2. Check that one of these environment variables is set: NANOBANANA_API_KEY, GEMINI_API_KEY, GOOGLE_API_KEY.
3. Run the bundled script:
   • Generate: python3 scripts/nanobanana.py generate --prompt "..." --out output/nanobanana/result.png
   • Generate with references: python3 scripts/nanobanana.py generate --prompt "..." --reference ref1.png --reference ref2.jpg
   • Edit: python3 scripts/nanobanana.py edit --input path/to/input.png --prompt "..." --out output/nanobanana/result.png
4. If the user asks for multiple variants, add --count N.
5. If the user provides one or more reference images, pass them with repeated --reference.
6. If the user asks for Pro quality, add --model gemini-3-pro-image-preview.
7. If the user wants the result to pop open automatically, add --preview.
8. Return the output path and, when helpful, show the generated image in the response.

Defaults

• Default model: gemini-3.1-flash-image-preview
• Default output format: png
• Default output directory when --out is omitted: output/nanobanana/
• edit accepts repeated --input so multiple source images can be combined in one request

Proxy notes

• If the machine relies on a local proxy, keep HTTP_PROXY and HTTPS_PROXY in the environment before running the script.
• If needed, set NANOBANANA_PROXY_URL explicitly.
• If neither proxy variable is set, the script will try a few common local proxy ports as a fallback.

Rules

• Prefer the bundled script over handwritten curl requests.
• Do not ask the user to paste API keys into chat.
• For edits, preserve the original image unless the user explicitly asks to overwrite it.
• If generation fails, surface the exact API error message and suggest switching model or checking key/project status.

Examples

python3 scripts/nanobanana.py generate \
  --prompt "a minimalist travel poster of Hangzhou West Lake at sunrise" \
  --out output/nanobanana/west-lake.png

python3 scripts/nanobanana.py generate \
  --prompt "three flat vector app icons for a note-taking app" \
  --count 3 \
  --model gemini-3-pro-image-preview \
  --out output/nanobanana/notes.png

python3 scripts/nanobanana.py generate \
  --prompt "create a mascot sticker based on the banana reference, with a playful black outline" \
  --reference assets/banana.png \
  --preview

python3 scripts/nanobanana.py edit \
  --input assets/photo.png \
  --prompt "replace the background with a clean warm beige studio backdrop" \
  --out output/nanobanana/photo-edit.png

python3 scripts/nanobanana.py edit \
  --input assets/product-front.png \
  --input assets/product-side.png \
  --prompt "combine these into one clean e-commerce hero image on a white background" \
  --preview