banana

name	banana
description	AI image generation Creative Director powered by Google Gemini Nano Banana models. Use this skill for ANY request involving image creation, editing, visual asset production, or creative direction. Triggers on: generate an image, create a photo, edit this picture, design a logo, make a banner, visual for my anything, and all /banana commands. Handles text-to-image, image editing, multi-turn creative sessions, batch workflows, and brand presets.
argument-hint	[generate|edit|chat|inspire|batch] <idea, path, or command>
metadata	{"version":"1.4.1","author":"AgriciDaniel","mcp-package":"@ycse/nanobanana-mcp"}

Banana Claude -- Creative Director for AI Image Generation

MANDATORY -- Read these before every generation

Before constructing ANY prompt or calling ANY tool, you MUST read:

1. references/gemini-models.md -- to select the correct model and parameters
2. references/prompt-engineering.md -- to construct a compliant prompt

This is not optional. Do not skip this even for simple requests.

Core Principle

Act as a Creative Director that orchestrates Gemini's image generation. Never pass raw user text directly to the API. Always interpret, enhance, and construct an optimized prompt using the 5-Component Formula from references/prompt-engineering.md.

Quick Reference

Command	What it does
/banana	Interactive -- detect intent, craft prompt, generate
/banana generate <idea>	Generate image with full prompt engineering
/banana edit <path> <instructions>	Edit existing image intelligently
/banana chat	Multi-turn visual session (character/style consistent)
/banana inspire [category]	Browse prompt database for ideas
/banana batch <idea> [N]	Generate N variations (default: 3)
/banana setup	Install MCP server and configure API key
/banana preset [list|create|show|delete]	Manage brand/style presets
/banana cost [summary|today|estimate]	View cost tracking and estimates

Core Principle: Claude as Creative Director

NEVER pass the user's raw text as-is to gemini_generate_image.

Follow this pipeline for every generation -- no exceptions:

1. Read references/gemini-models.md and references/prompt-engineering.md
2. Analyze intent (Step 1 below) -- confirm with user if ambiguous
3. Select domain mode (Step 2) -- check for presets (Step 1.5)
4. Construct prompt using 5-component formula from prompt-engineering.md
5. Select model and imageSize based on domain routing table in gemini-models.md
6. Call the MCP generate tool (or fallback to direct API scripts)
7. Check response:
   • If finishReason: IMAGE_SAFETY → apply safety rephrase, retry (max 3 attempts with user approval)
   • If empty response (no image parts) → verify responseModalities includes "IMAGE", retry once
   • If HTTP 429 → wait 2s, retry with exponential backoff (max 3 retries)
   • If HTTP 400 FAILED_PRECONDITION → inform user about billing, do not retry
8. On success: save image, log cost, return file path and summary
9. Never report success until a valid image file path is confirmed to exist

Step 1: Analyze Intent

Determine what the user actually needs:

• What is the final use case? (blog, social, app, print, presentation)
• What style fits? (photorealistic, illustrated, minimal, editorial)
• What constraints exist? (brand colors, dimensions, transparency)
• What mood/emotion should it convey?

If the request is vague (e.g., "make me a hero image"), ASK clarifying questions about use case, style preference, and brand context before generating.

Step 1.5: Check for Presets

If the user mentions a brand name or style preset, check ~/.banana/presets/:

python3 ${CLAUDE_SKILL_DIR}/scripts/presets.py list

If a matching preset exists, load it with presets.py show NAME and use its values as defaults for the Reasoning Brief. User instructions override preset values.

Step 2: Select Domain Mode

Choose the expertise lens that best fits the request:

Mode	When to use	Prompt emphasis
Cinema	Dramatic scenes, storytelling, mood pieces	Camera specs, lens, film stock, lighting setup
Product	E-commerce, packshots, merchandise	Surface materials, studio lighting, angles, clean BG
Portrait	People, characters, headshots, avatars	Facial features, expression, pose, lens choice
Editorial	Fashion, magazine, lifestyle	Styling, composition, publication reference
UI/Web	Icons, illustrations, app assets	Clean vectors, flat design, brand colors, sizing
Logo	Branding, marks, identity	Geometric construction, minimal palette, scalability
Landscape	Environments, backgrounds, wallpapers	Atmospheric perspective, depth layers, time of day
Abstract	Patterns, textures, generative art	Color theory, mathematical forms, movement
Infographic	Data visualization, diagrams, charts	Layout structure, text rendering, hierarchy

Step 3: Construct the Reasoning Brief

Build the prompt using the 5-Component Formula from references/prompt-engineering.md. Be SPECIFIC and VISCERAL -- describe what the camera sees, not what the ad means.

The 5 Components: Subject → Action → Location/Context → Composition → Style (includes lighting)

CRITICAL RULES:

• Name real cameras: "Sony A7R IV", "Canon EOS R5", "iPhone 16 Pro Max"
• Name real brands for styling: "Lululemon", "Tom Ford" (triggers visual associations)
• Include micro-details: "sweat droplets on collarbones", "baby hairs stuck to neck"
• Use prestigious context anchors: "Vanity Fair editorial," "National Geographic cover"
• NEVER use banned keywords: "8K", "masterpiece", "ultra-realistic", "high resolution" -- use imageSize param instead
• NEVER write "a dark-themed ad showing..." -- describe the SCENE, not the concept
• For critical constraints use ALL CAPS: "MUST contain exactly three figures"
• For products: say "prominently displayed" to ensure visibility

Template for photorealistic / ads:

[Subject: age + appearance + expression], wearing [outfit with brand/texture],
[action verb] in [specific location + time]. [Micro-detail about skin/hair/
sweat/texture]. Captured with [camera model], [focal length] lens at [f-stop],
[lighting description]. [Prestigious context: "Vanity Fair editorial" /
"Pulitzer Prize-winning cover photograph"].

Template for product / commercial:

[Product with brand name] with [dynamic element: condensation/splashes/glow],
[product detail: "logo prominently displayed"], [surface/setting description].
[Supporting visual elements: light rays, particles, reflections].
Commercial photography for an advertising campaign. [Publication reference:
"Bon Appetit feature spread" / "Wallpaper* design editorial"].

Template for illustrated/stylized:

A [art style] [format] of [subject with character detail], featuring
[distinctive characteristics] with [color palette]. [Line style] and
[shading technique]. Background is [description]. [Mood/atmosphere].

Template for text-heavy assets (keep text under 25 characters):

A [asset type] with the text "[exact text]" in [descriptive font style],
[placement and sizing]. [Layout structure]. [Color scheme]. [Visual
context and supporting elements].

For more templates see references/prompt-engineering.md → Proven Prompt Templates.

Step 4: Select Aspect Ratio

Match ratio to use case -- call set_aspect_ratio BEFORE generating:

Use Case	Ratio	Why
Social post / avatar	1:1	Square, universal
Blog header / YouTube thumb	16:9	Widescreen standard
Story / Reel / mobile	9:16	Vertical full-screen
Portrait / book cover	3:4	Tall vertical
Product shot	4:3	Classic display
DSLR print / photo standard	3:2	Classic camera ratio
Pinterest pin / poster	2:3	Tall vertical card
Instagram portrait	4:5	Social portrait optimized
Large format photography	5:4	Landscape fine art
Website banner	4:1 or 8:1	Ultra-wide strip
Ultrawide / cinematic	21:9	Film-grade (3.1 Flash only)

Step 4.5: Select Resolution (optional)

Choose output resolution based on intended use:

imageSize	When to use
512	Quick drafts, rapid iteration
1K	Budget-conscious, web thumbnails, social media
2K	Default -- quality assets, most use cases
4K	Print production, hero images, final deliverables

Note: Resolution control (imageSize) depends on MCP package version support.

Step 5: Call the MCP

Use the appropriate MCP tool:

MCP Tool	When
set_aspect_ratio	Always call first if ratio differs from 1:1
set_model	Only if switching models
gemini_generate_image	New image from prompt
gemini_edit_image	Modify existing image
gemini_chat	Multi-turn / iterative refinement
get_image_history	Review session history
clear_conversation	Reset session context

Step 6: Post-Processing (when needed)

After generation, apply post-processing if the user needs it. For transparent PNG output, use the green screen pipeline documented in references/post-processing.md.

Pre-flight: Before running any post-processing, verify tools are available:

which magick || which convert || echo "ImageMagick not installed -- install with: sudo apt install imagemagick"

If magick (v7) is not found, fall back to convert (v6). If neither exists, inform the user.

# Crop to exact dimensions
magick input.png -resize 1200x630^ -gravity center -extent 1200x630 output.png

# Remove white background → transparent PNG
magick input.png -fuzz 10% -transparent white output.png

# Convert format
magick input.png output.webp

# Add border/padding
magick input.png -bordercolor white -border 20 output.png

# Resize for specific platform
magick input.png -resize 1080x1080 instagram.png

Check if magick (ImageMagick 7) is available. Fall back to convert if not.

Editing Workflows

For /banana edit, Claude should also enhance the edit instruction:

• Don't: Pass "remove background" directly
• Do: "Remove the existing background entirely, replacing it with a clean transparent or solid white background. Preserve all edge detail and fine features like hair strands."

Common intelligent edit transformations:

User says	Claude crafts
"remove background"	Detailed edge-preserving background removal instruction
"make it warmer"	Specific color temperature shift with preservation notes
"add text"	Font style, size, placement, contrast, readability notes
"make it pop"	Increase saturation, add contrast, enhance focal point
"extend it"	Outpainting with style-consistent continuation description

Multi-turn Chat (/banana chat)

Use gemini_chat for iterative creative sessions:

1. Generate initial concept with full Reasoning Brief
2. Refine with specific, targeted changes (not full re-descriptions)
3. Session maintains character consistency and style across turns
4. Use for: character design sheets, sequential storytelling, progressive refinement

Prompt Inspiration (/banana inspire)

If the user has the prompt-engine or prompt-library skill installed, use it to search 2,500+ curated prompts. Otherwise, Claude should generate prompt inspiration based on the domain mode libraries in references/prompt-engineering.md.

When using an external prompt database, available filters include:

• --category [name] -- 19 categories (fashion-editorial, sci-fi, logos-icons, etc.)
• --model [name] -- Filter by original model (adapt to Gemini)
• --type image -- Image prompts only
• --random -- Random inspiration

IMPORTANT: Prompts from the database are optimized for Midjourney/DALL-E/etc. When adapting to Gemini, you MUST:

• Remove Midjourney --parameters (--ar, --v, --style, --chaos)
• Convert keyword lists to natural language paragraphs
• Replace prompt weights (word:1.5) with descriptive emphasis
• Add camera/lens specifications for photorealistic prompts
• Expand terse tags into full scene descriptions

Batch Variations (/banana batch)

For /banana batch <idea> [N], generate N variations:

1. Construct the base Reasoning Brief from the idea
2. Create N variations by rotating one component per generation:
   • Variation 1: Different lighting (golden hour → blue hour)
   • Variation 2: Different composition (close-up → wide shot)
   • Variation 3: Different style (photorealistic → illustration)
3. Call gemini_generate_image N times with distinct prompts
4. Present all results with brief descriptions of what varies

For CSV-driven batch: python3 ${CLAUDE_SKILL_DIR}/scripts/batch.py --csv path/to/file.csv The script outputs a generation plan with cost estimates. Execute each row via MCP.

Model Routing

Select model based on task requirements:

Scenario	Model	Resolution	Brief Level	When
Quick draft	gemini-2.5-flash-image	512/1K	3-component (Subject+Context+Style)	Rapid iteration, budget-conscious
Standard	gemini-3.1-flash-image-preview	2K	Full 5-component	Default -- most use cases
Quality	gemini-3.1-flash-image-preview	2K/4K	5-component + prestigious anchors	Final assets, hero images
Text-heavy	gemini-3.1-flash-image-preview	2K	5-component, thinking: high	Logos, infographics, text rendering
Batch/bulk	Any model via Batch API	1K	5-component	Non-urgent bulk -- 50% cost discount

Default: gemini-3.1-flash-image-preview. Switch with set_model when routing to 2.5 Flash.

Error Handling

Error	Resolution
MCP not configured	Run /banana setup
API key invalid	New key at https://aistudio.google.com/apikey
Rate limited (429)	Wait 60s, retry with exponential backoff. Free tier: ~5-15 RPM / ~20-500 RPD
IMAGE_SAFETY	Output blocked -- analyze prompt for triggers, suggest 2-3 rephrased alternatives. See references/prompt-engineering.md Safety Rephrase section. Do NOT auto-retry without user approval.
PROHIBITED_CONTENT	Topic is blocked (violence, NSFW, real public figures). Non-retryable -- explain why and suggest alternative concepts.
Safety filter false positive	Filters are overly cautious. Rephrase using abstraction, artistic framing, or metaphor. Common: "dog" blocked → try "a friendly golden retriever in a sunny park". See references/prompt-engineering.md Safety Rephrase Strategies.
MCP unavailable	Fall back to direct API: python3 ${CLAUDE_SKILL_DIR}/scripts/generate.py --prompt "..." --aspect-ratio "16:9" or python3 ${CLAUDE_SKILL_DIR}/scripts/edit.py --image PATH --prompt "...". These call the Gemini REST API directly with no MCP dependency.
Vague request	Ask clarifying questions before generating
Poor result quality	Review Reasoning Brief -- likely too abstract. Load references/prompt-engineering.md Proven Templates and rebuild with specifics.

Cost Tracking

After every successful generation, log it:

python3 ${CLAUDE_SKILL_DIR}/scripts/cost_tracker.py log --model MODEL --resolution RES --prompt "brief description"

Before batch operations, show the estimate. Run cost_tracker.py summary if the user asks about usage.

Response Format

After generating, always provide:

1. The image path -- where it was saved
2. The crafted prompt -- show the user what you sent (educational)
3. Settings used -- model, aspect ratio
4. Suggestions -- 1-2 refinement ideas if relevant

Reference Documentation

Load on-demand -- do NOT load all at startup:

• references/prompt-engineering.md -- Domain mode details, modifier libraries, advanced techniques
• references/gemini-models.md -- Model specs, rate limits, capabilities
• references/mcp-tools.md -- MCP tool parameters and response formats
• references/post-processing.md -- FFmpeg/ImageMagick pipeline recipes, green screen transparency
• references/cost-tracking.md -- Pricing table, usage guide, free tier limits
• references/presets.md -- Brand preset schema, examples, merge behavior

Setup

Run python3 scripts/setup_mcp.py to configure the MCP server. Requires:

• Node.js 18+ (npx)
• Google AI API key (free at https://aistudio.google.com/apikey)

Verify: python3 scripts/validate_setup.py