| name | nano-banana-pro |
| description | Generate and edit images using Google's Nano Banana Pro (Gemini 3 Pro Image) API. Use when the user asks to generate, create, edit, modify, change, alter, or update images. Also use when user references an existing image file and asks to modify it in any way (e.g., "modify this image", "change the background", "replace X with Y"). Supports both text-to-image generation and image-to-image editing with configurable resolution (1K default, 2K, or 4K for high resolution). DO NOT read the image file first - use this skill directly with the --input-image parameter. |
Nano Banana Pro Image Generation & Editing
Generate new images or edit existing ones using Google's Nano Banana Pro API (Gemini 3 Pro Image).
Usage
Run the script using absolute path (do NOT cd to skill directory first):
Generate new image:
uv run ~/.claude/skills/nano-banana-pro/scripts/generate_image.py --prompt "your image description" --filename "output-name.png" [--resolution 1K|2K|4K] [--api-key KEY]
Edit existing image:
uv run ~/.claude/skills/nano-banana-pro/scripts/generate_image.py --prompt "editing instructions" --filename "output-name.png" --input-image "path/to/input.png" [--resolution 1K|2K|4K] [--api-key KEY]
Important: Always run from the user's current working directory so images are saved where the user is working, not in the skill directory.
Resolution Options
The Gemini 3 Pro Image API supports three resolutions (uppercase K required):
- 1K (default) - ~1024px resolution
- 2K - ~2048px resolution
- 4K - ~4096px resolution
Map user requests to API parameters:
- No mention of resolution →
1K
- "low resolution", "1080", "1080p", "1K" →
1K
- "2K", "2048", "normal", "medium resolution" →
2K
- "high resolution", "high-res", "hi-res", "4K", "ultra" →
4K
API Key
The script checks for API key in this order:
--api-key argument (use if user provided key in chat)GEMINI_API_KEY environment variable
If neither is available, the script exits with an error message.
Filename Generation
Generate filenames with the pattern: yyyy-mm-dd-hh-mm-ss-name.png
Format: {timestamp}-{descriptive-name}.png
- Timestamp: Current date/time in format
yyyy-mm-dd-hh-mm-ss (24-hour format)
- Name: Descriptive lowercase text with hyphens
- Keep the descriptive part concise (1-5 words typically)
- Use context from user's prompt or conversation
- If unclear, use random identifier (e.g.,
x9k2, a7b3)
Examples:
- Prompt "A serene Japanese garden" →
2025-11-23-14-23-05-japanese-garden.png
- Prompt "sunset over mountains" →
2025-11-23-15-30-12-sunset-mountains.png
- Prompt "create an image of a robot" →
2025-11-23-16-45-33-robot.png
- Unclear context →
2025-11-23-17-12-48-x9k2.png
Image Editing
When the user wants to modify an existing image:
- Check if they provide an image path or reference an image in the current directory
- Use
--input-image parameter with the path to the image
- The prompt should contain editing instructions (e.g., "make the sky more dramatic", "remove the person", "change to cartoon style")
- Common editing tasks: add/remove elements, change style, adjust colors, blur background, etc.
Prompt Handling
For generation: Pass user's image description as-is to --prompt. Only rework if clearly insufficient.
For editing: Pass editing instructions in --prompt (e.g., "add a rainbow in the sky", "make it look like a watercolor painting")
Preserve user's creative intent in both cases.
Output
- Saves PNG to current directory (or specified path if filename includes directory)
- Script outputs the full path to the generated image
- Do not read the image back - just inform the user of the saved path
Examples
Generate new image:
uv run ~/.claude/skills/nano-banana-pro/scripts/generate_image.py --prompt "A serene Japanese garden with cherry blossoms" --filename "2025-11-23-14-23-05-japanese-garden.png" --resolution 4K
Edit existing image:
uv run ~/.claude/skills/nano-banana-pro/scripts/generate_image.py --prompt "make the sky more dramatic with storm clouds" --filename "2025-11-23-14-25-30-dramatic-sky.png" --input-image "original-photo.jpg" --resolution 2K
