nano-banana

name	nano-banana
description	REQUIRED for all image generation requests. Generate and edit images using Nano Banana (Gemini CLI). Handles blog featured images, YouTube thumbnails, icons, diagrams, patterns, illustrations, photos, visual assets, graphics, artwork, pictures. Also routes specialty creative recipes (anime-to-life, character-reference-sheet, figure-to-life, imax-portrait, j-cover, j-idol, j-poses, photo-restoration, real-mecha). Use this skill whenever the user asks to create, generate, make, draw, design, or edit any image or visual content.
allowed-tools	Bash(gemini:*)
version	1.0.0
category	utility

Nano Banana Image Generation

Generate professional images via the Gemini CLI's nanobanana extension. This skill is both the generic image-generation surface AND the router for specialty creative recipes.

When to Use This Skill

ALWAYS use this skill when the user:

• Asks for any image, graphic, illustration, or visual
• Wants a thumbnail, featured image, or banner
• Requests icons, diagrams, or patterns
• Asks to edit, modify, or restore a photo
• Uses words like: generate, create, make, draw, design, visualize
• Names one of the specialty recipes below (e.g. "make this an IMAX portrait", "j-idol gravure", "real mecha")

Do NOT attempt to generate images through any other method.

Specialty Recipes (load on demand)

When the user's request matches one of these recipes — by name or by intent — call get_skill_file(name="nano-banana", path="references/<recipe>.md") on gobby-skills and follow that file's instructions, then generate via the commands below.

Recipe	Use when the user asks for…
anime-to-life	Turning anime/art/3D characters into photorealistic cosplayer photos
character-reference-sheet	A 3-column character sheet (portrait + front + back) in a matching style
figure-to-life	Converting a figure/statue/toy photo into a photorealistic human cosplayer
imax-portrait	Recomposing a portrait into 1.43:1 IMAX 70mm framing with bokeh and grain
j-cover	Turning a character image into a Japanese magazine cover with bilingual typography
j-idol	Photorealistic J-Idol gravure portrait (2:3 knee-up, dreamy bokeh, rim light)
j-poses	A pose library to mix into other prompts (silhouette/line/mood reference)
photo-restoration	Restoring blurry/vintage photos to clean 8k while preserving identity
real-mecha	Converting 2D mecha art into a photorealistic hard-surface render

If the request doesn't match a specialty recipe, skip this section and use the generic commands below.

If get_skill_file returns {"success": false, ...}, surface the error to the user and fall back to generic generation.

Before First Use

1. Verify extension is installed:

   gemini extensions list | grep nanobanana
   

2. If missing, install it:

   gemini extensions install https://github.com/gemini-cli-extensions/nanobanana
   

3. Verify API key is set:

   [ -n "$GEMINI_API_KEY" ] && echo "API key configured" || echo "Missing GEMINI_API_KEY"
   

Command Selection

User Request	Command
"make me a blog header"	/generate
"create an app icon"	/icon
"draw a flowchart of..."	/diagram
"fix this old photo"	/restore
"remove the background"	/edit
"create a repeating texture"	/pattern
"make a comic strip"	/story

Available Commands

Note: Always use the --yolo flag to automatically approve all tool actions.

Command	Use Case
gemini --yolo "/generate 'prompt'"	Text-to-image generation
gemini --yolo "/edit file.png 'instruction'"	Modify existing image
gemini --yolo "/restore old_photo.jpg 'fix scratches'"	Repair damaged photos
gemini --yolo "/icon 'description'"	App icons, favicons, UI elements
gemini --yolo "/diagram 'description'"	Flowcharts, architecture diagrams
gemini --yolo "/pattern 'description'"	Seamless textures and patterns
gemini --yolo "/story 'description'"	Sequential/narrative images
gemini --yolo "/nanobanana prompt"	Natural language interface

Common Options

• --yolo - Required. Auto-approve all tool actions (no confirmation prompts)
• --count=N - Generate N variations (1-8)
• --preview - Auto-open generated images
• --styles="style1,style2" - Apply artistic styles
• --format=grid|separate - Output arrangement

Common Sizes

Use Case	Dimensions	Notes
YouTube thumbnail	1280x720	--aspect=16:9
Blog featured image	1200x630	Social preview friendly
Square social	1080x1080	Instagram, LinkedIn
Twitter/X header	1500x500	Wide banner
Vertical story	1080x1920	--aspect=9:16

Model Selection

Default: gemini-2.5-flash-image (~$0.04/image)

For higher quality (4K, better reasoning):

export NANOBANANA_MODEL=gemini-3-pro-image-preview

Blog Featured Image Examples

# Modern illustration style
gemini --yolo "/generate 'modern flat illustration of developer coding at laptop, purple and blue gradient background, minimalist style, no text' --preview"

# Professional photography style
gemini --yolo "/generate 'professional editorial photo of coffee cup next to laptop on wooden desk, morning sunlight, shallow depth of field, no text' --count=3"

# Tech/abstract
gemini --yolo "/generate 'abstract visualization of neural network connections, dark background with glowing blue nodes, futuristic style' --preview"

Icon Generation

gemini --yolo "/icon 'minimalist app logo for productivity tool' --sizes='64,128,256,512' --type='app-icon' --corners='rounded'"

Diagram Generation

gemini --yolo "/diagram 'user authentication flow with OAuth' --type='flowchart' --style='modern'"

Output Location

All generated images are saved to ./nanobanana-output/ in the current directory.

Presenting Results

After generation completes:

1. List contents of ./nanobanana-output/ to find generated files
2. Present the most recent image(s) to the user
3. Offer to regenerate with variations if needed

Refinements and Iterations

When the user asks for changes:

• "Try again" / "Give me options": Regenerate with --count=3
• "Make it more [adjective]": Adjust prompt and regenerate
• "Edit this one": Use gemini --yolo "/edit nanobanana-output/filename.png 'adjustment'"
• "Different style": Add --styles="requested_style" to the command

Prompt Tips

1. Be specific: Include style, mood, colors, composition details
2. Add "no text": If you don't want text rendered in the image
3. Reference styles: "editorial photography", "flat illustration", "3D render", "watercolor"
4. Specify aspect ratio context: "wide banner", "square thumbnail", "vertical story"

Troubleshooting

Problem	Solution
GEMINI_API_KEY not set	export GEMINI_API_KEY="your-key"
Extension not found	Run install command from setup section
Quota exceeded	Wait for reset or switch to flash model
Image generation failed	Check prompt for policy violations, simplify request
Output directory missing	Will be created automatically on first run
Specialty recipe not found	Verify the recipe name against the table above; fall back to generic generation if needed