/nano-banana - Generate AI Images

You are helping the user generate an image using the nano-banana CLI, powered by Google's Gemini image generation models.

Tool Location

The CLI tool is at: ${CLAUDE_PLUGIN_ROOT}/tools/cli.ts

Run with: bun run "${CLAUDE_PLUGIN_ROOT}/tools/cli.ts" [PROMPT] [OPTIONS]

Prerequisites Check

Before first use, verify dependencies are installed:

cd "${CLAUDE_PLUGIN_ROOT}/tools" && [ -d "node_modules" ] && echo "READY" || echo "NEEDS_INSTALL"

If NEEDS_INSTALL, run:

cd "${CLAUDE_PLUGIN_ROOT}/tools" && bun install

Interactive Flow

1. Check What's Provided

Parse the command arguments:

• $ARGUMENTS.prompt - Image prompt
• $ARGUMENTS.size - Size (512, 1K, 2K, 4K)
• $ARGUMENTS.model - Model (flash, pro)
• $ARGUMENTS.aspect-ratio - Aspect ratio
• $ARGUMENTS.output - Output filename
• $ARGUMENTS.transparent - Transparent background
• $ARGUMENTS.ref - Reference image path
• $ARGUMENTS.no-search - Disable search grounding

2. Gather Missing Required Information

If prompt is missing, ask the user:

What image would you like to generate? Describe the subject, style, and composition.

3. Optional Enhancements

If size/model/aspect were not provided, ask with sensible defaults:

Size (if not provided, default to 1K):

• 512 (~$0.045 Flash) - Quick concepts
• 1K (~$0.067 Flash) - Standard quality (Recommended)
• 2K (~$0.101 Flash) - High quality
• 4K (~$0.151 Flash) - Ultra high quality

Model (if not provided, default to flash):

• flash - Fast, cheap (Recommended for most uses)
• pro - Highest quality, 2x cost

Aspect Ratio (only ask if relevant to the prompt):

• 1:1 - Square (default)
• 16:9 - Widescreen/landscape
• 9:16 - Portrait/mobile
• 4:3 - Standard photo

4. Output Path

If output is not provided, generate a descriptive default based on the prompt:

[descriptive-slug]-[timestamp]

Use -d flag to place in ~/Downloads or the user's preferred directory.

5. Build and Run Command

Construct the full command:

bun run "${CLAUDE_PLUGIN_ROOT}/tools/cli.ts" "USER_PROMPT" \
  [-s SIZE] \
  [-m MODEL] \
  [-a ASPECT_RATIO] \
  [-o OUTPUT_NAME] \
  [-d OUTPUT_DIR] \
  [-r REFERENCE_IMAGE] \
  [-t] \
  [--no-search]

6. Report Results

After completion, report:

• Output file path and size
• Estimated cost
• Search grounding sources (if any were used)
• Suggest next steps (edit with reference, try different size, etc.)

Example Flows

Full Arguments Provided

/nano-banana "A sunset over mountains" --size 2K --aspect-ratio 16:9 --output sunset

-> Build command and run immediately

Prompt Only

/nano-banana "A minimalist logo for a tech startup"

-> Use defaults (1K, flash, 1:1), generate with descriptive filename

Interactive (No Arguments)

/nano-banana

-> Ask for prompt, use sensible defaults, generate

Transparent Asset

/nano-banana "pixel art robot character" --transparent --output robot

-> Run with -t flag, report transparent PNG output

Reference Image

/nano-banana "make this image brighter and more vibrant" --ref ./screenshot.png

-> Run with -r flag for image editing

Models Reference

Alias	Model	Cost/1K	Best For
flash, nb2	Gemini 3.1 Flash	~$0.067	Speed, volume, iteration (web + image search grounding)
pro, nb-pro	Gemini 3 Pro	~$0.134	Final quality, complex (web search grounding only)

Important Notes

• Always quote the prompt string in the bash command
• For transparent mode, user needs FFmpeg + ImageMagick installed
• Reference images must exist at the specified path - verify before running
• Cost tracking is automatic - user can check with --costs flag
• Flash model uses Google Search grounding (web + image search) by default for real-world accuracy
• Use --no-search to disable grounding for abstract/creative prompts