Nano Banana Image Generation

When to Use This Skill

• 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

Before First Use

1. Verify extension is installed:
   bash

   gemini extensions list | grep nanobanana

2. If missing, install it:
   bash

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

3. Verify API key is set:
   bash

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

Command Selection

/generate

/icon

/diagram

/restore

/edit

/pattern

/story

Available Commands

--yolo

gemini --yolo "/generate 'prompt'"

gemini --yolo "/edit file.png 'instruction'"

gemini --yolo "/restore old_photo.jpg 'fix scratches'"

gemini --yolo "/icon 'description'"

gemini --yolo "/diagram 'description'"

gemini --yolo "/pattern 'description'"

gemini --yolo "/story 'description'"

gemini --yolo "/nanobanana prompt"

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

--aspect=16:9

--aspect=9:16

Model Selection

gemini-2.5-flash-image

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

./nanobanana-output/

Presenting Results

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

• "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

GEMINI_API_KEY

export GEMINI_API_KEY="your-key"