| name | nano-banana |
| description | Generate or edit images with OpenRouter using the google/gemini-3.1-flash-image-preview model. Use when the user asks for image generation, wants a new visual from a text prompt, or wants modifications to an existing screenshot or image and expects an image file back. |
| allowed-tools | Bash(node agent/skills/nano-banana/generate-image.js:*) |
Nano Banana Image Generation
Use this skill when the user wants an image back, either from a fresh prompt or from editing an existing image.
Model
- Provider: OpenRouter
- Model:
google/gemini-3.1-flash-image-preview
- Friendly name: Nano Banana
Supported workflows
- Text-to-image: user provides a prompt, you generate an image.
- Image edit: user provides an image or screenshot plus instructions, you generate a modified image.
Before you run
- Make sure the prompt is explicit enough to produce the desired image.
- If editing an image, first save or locate the input image path in the workspace.
- The script writes generated files to
.context/generated-images/ by default.
Usage
Generate a new image
node agent/skills/nano-banana/generate-image.js \
--prompt "A clean product hero shot of a matte black coffee grinder on a soft beige background, studio lighting" \
--output .context/generated-images/coffee-grinder.png
Edit an existing image
node agent/skills/nano-banana/generate-image.js \
--prompt "Keep the layout the same, but change the CTA button to green, replace the headline with 'Ship faster', and make the page look more premium" \
--input-image path/to/screenshot.png \
--output .context/generated-images/edited-screenshot.png
Response handling
- The script prints JSON with an
output field containing the saved image path.
- After running it, tell the user the output file path.
- If the model returns no image, inspect the JSON warning and summarize the failure clearly.
Notes
- Prefer PNG outputs unless the user asks for another format.
- Preserve existing composition when the user asks for modifications to a screenshot.
- If the user’s request is ambiguous, clarify what should change and what must remain untouched.
