image-generation

name	image-generation
description	Generate or edit images with Nano Banana 2 (Gemini 3.1 Flash Image). Use for any image create/modify requests. Supports text-to-image + image-to-image; 1K/2K/4K resolutions.

Image Generation (Nano Banana 2)

Generate new images or edit existing ones using Google's Gemini 3.1 Flash Image API.

Usage

Run the bundled script via shell. Images are saved to $WORKSPACE/tmp/.

Generate new image:

uv run {{skill_dir}}/scripts/generate_image.py --prompt 'your image description' --filename 'tmp/yyyy-mm-dd-hh-mm-ss-name.png'

Edit existing image:

uv run {{skill_dir}}/scripts/generate_image.py --prompt 'editing instructions' --filename 'tmp/yyyy-mm-dd-hh-mm-ss-name.png' --input-image 'path/to/input.png'

Resolution option: Append --resolution 1K|2K|4K (default: 1K).

Filename Convention

yyyy-mm-dd-hh-mm-ss-descriptive-name.png

• Timestamp in 24-hour format
• Descriptive lowercase text with hyphens (1-5 words)
• Derive from the user's prompt or conversation context
• If unclear, use a random identifier (e.g. x9k2)

Prompt Handling

For generation: Pass the OPERATOR'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 the OPERATOR's creative intent in both cases.

Prompt Templates (for vague requests)

• Generation: "Create an image of: . Style: . Composition: <camera/shot>. Lighting: <lighting>. Background: <background>. Color palette: <palette>. Avoid: <list>."
• Editing (preserve everything else): "Change ONLY: . Keep identical: subject, composition/crop, pose, lighting, color palette, background, text, and overall style. Do not add new objects."

Common Failures

• Error: No API key provided. -> set GEMINI_API_KEY in .env
• Error loading input image: -> wrong path or unreadable file
• 403 / quota errors -> wrong key, no access, or quota exceeded

Output

• Saves PNG to the specified path (always under $WORKSPACE/tmp/)
• Script outputs the full path to the generated image
• Do not read the image back — just inform the OPERATOR of the saved path