# Nano Banana Prompting Skill

> Transform natural language image requests into optimized structured prompts for Gemini image generation. Automatically detects style and builds the perfect prompt — cinematic, illustration, anime, 3D, watercolor, product, and more.

- **Type:** Skill
- **Install:** `agentstack add skill-minilozio-nano-banana-prompting-skill-nano-banana-prompting-skill`
- **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior
- **Seller:** [minilozio](https://agentstack.voostack.com/s/minilozio)
- **Installs:** 0
- **Category:** [Content & Media](https://agentstack.voostack.com/c/content-and-media)
- **Latest version:** 0.1.0
- **License:** MIT
- **Upstream author:** [minilozio](https://github.com/minilozio)
- **Source:** https://github.com/minilozio/nano-banana-prompting-skill

## Install

```sh
agentstack add skill-minilozio-nano-banana-prompting-skill-nano-banana-prompting-skill
```

Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent.

## About

# Gemini Image Prompting

This skill transforms simple, natural image requests into **optimized structured prompts** that produce dramatically better results from Gemini 3 Pro Image.

Instead of sending a plain text prompt (which produces generic, "AI slop" results), this skill builds a **structured JSON prompt** with the right technical details for the detected style — camera specs for photography, art techniques for illustration, render settings for 3D, and more.

## How to Use

When the user asks you to generate or edit an image:

1. **Read the user's request** — understand what they want (subject, mood, style)
2. **Detect the style** — use the Style Detection rules below
3. **Build the structured JSON prompt** — follow the template for that style
4. **Call the generator:**

```bash
uv run {nano-banana-pro-dir}/scripts/generate_image.py \
  --prompt '' \
  --filename ".png" \
  --resolution 2K
```

Replace `{nano-banana-pro-dir}` with the path to the nano-banana-pro skill (typically bundled with OpenClaw).

**For image editing** (user provides a reference image):
```bash
uv run {nano-banana-pro-dir}/scripts/generate_image.py \
  --prompt '' \
  --filename ".png" \
  -i "/path/to/reference.png" \
  --resolution 2K
```

### Security Note
The `--filename` argument should always be a simple file path constructed by the agent (e.g., `gecko-running.png`). Never pass unsanitized user input directly as the filename. The agent should derive a safe, descriptive filename from the context.

### Output Location
Save images to the user's Desktop or the path they specify:
- Default: `~/Desktop/.png`
- Use descriptive filenames: `gecko-coding-night.png`, not `output.png`

---

## Style Detection

Detect the style from the user's request. Look for keywords, context, and intent:

| Style | Trigger Keywords / Context |
|-------|---------------------------|
| **Cinematic / Photorealistic** | "photo", "realistic", "cinematic", "portrait", "street", "landscape", real-world scenes, people, animals in real settings |
| **Product / Studio** | "product shot", "studio", "mockup", "packaging", "e-commerce", objects on clean backgrounds |
| **Street / Documentary** | "candid", "street", "reportage", "documentary", "raw", urban scenes |
| **Illustration / Digital Art** | "illustration", "digital art", "concept art", "fantasy art", "draw", "artwork" |
| **Anime / Manga** | "anime", "manga", "cel shaded", "studio ghibli", Japanese animation style |
| **3D / Pixar** | "3D", "Pixar", "render", "CGI", "clay", "isometric", cartoon characters |
| **Watercolor / Traditional** | "watercolor", "oil painting", "sketch", "pencil", "pastel", "charcoal", traditional media |
| **Minimalist / Graphic** | "logo", "icon", "flat", "minimal", "vector", "graphic design", "poster" |
| **Surreal / Abstract** | "surreal", "abstract", "dreamlike", "psychedelic", "impossible", "Dalí" |

**If no style is obvious**, default to **Cinematic / Photorealistic** — it's the most versatile and produces the best baseline quality.

**If the user specifies a style explicitly**, always respect that over auto-detection.

---

## Structured Prompt Templates

### 🎬 Cinematic / Photorealistic

```json
{
  "instruction": "",
  "subject": {
    "description": "",
    "clothing": "",
    "expression": "",
    "pose": "",
    "details": ""
  },
  "scene": {
    "setting": "",
    "key_elements": "",
    "background": "",
    "foreground": "",
    "time_of_day": ""
  },
  "photography": {
    "camera": "",
    "lens": "",
    "shot_type": "",
    "depth_of_field": "",
    "lighting": "",
    "film_stock": "",
    "texture": ""
  },
  "mood": "",
  "color_palette": "",
  "aspect_ratio": "",
  "quality": "8K, photorealistic, cinematic, RAW photo",
  "negative": "no text, no watermark, no deformed faces, no extra limbs, no blurry"
}
```

**Camera selection guide:**
- Portraits → Hasselblad X2D or Canon R5 + 85mm
- Street/documentary → Leica M11 + 35mm
- Landscapes/cinematic → Sony A7IV + 24mm or ARRI Alexa 65
- Night/low light → Sony A7IV + 50mm f/1.2 + CineStill 800T
- Fashion → Hasselblad X2D + 80mm

### 📸 Product / Studio

```json
{
  "instruction": "",
  "subject": {
    "product": "",
    "material": "",
    "color": "",
    "details": ""
  },
  "scene": {
    "backdrop": "",
    "surface": "",
    "props": ""
  },
  "photography": {
    "camera": "Hasselblad X2D",
    "lens": "90mm f/3.2 macro",
    "shot_type": "",
    "lighting": "",
    "reflections": "",
    "depth_of_field": "shallow, product sharp, background soft"
  },
  "mood": "",
  "color_palette": "",
  "aspect_ratio": "1:1",
  "quality": "8K, commercial photography, sharp detail, color-accurate",
  "negative": "no text, no watermark, no dust, no scratches"
}
```

### 🖌️ Illustration / Digital Art

```json
{
  "instruction": "",
  "subject": {
    "character": "",
    "expression": "",
    "pose": "",
    "details": ""
  },
  "scene": {
    "setting": "",
    "key_elements": "",
    "atmosphere": ""
  },
  "art_style": {
    "medium": "",
    "technique": "",
    "reference_artists": "",
    "color_approach": ""
  },
  "composition": {
    "framing": "",
    "perspective": "",
    "focal_point": ""
  },
  "mood": "",
  "color_palette": "",
  "aspect_ratio": "",
  "quality": "highly detailed illustration, trending on ArtStation, masterpiece",
  "negative": "no text, no watermark, no photo-realistic, no AI artifacts"
}
```

### 🌸 Anime / Manga

```json
{
  "instruction": "",
  "subject": {
    "character": "",
    "hair": "",
    "eyes": "",
    "outfit": "",
    "pose": ""
  },
  "scene": {
    "setting": "",
    "atmosphere": "",
    "background_style": ""
  },
  "art_style": {
    "studio_reference": "",
    "line_weight": "",
    "shading": "",
    "era": ""
  },
  "composition": {
    "framing": "",
    "effects": ""
  },
  "mood": "",
  "color_palette": "",
  "aspect_ratio": "16:9",
  "quality": "anime key visual, high detail, studio quality, clean lines",
  "negative": "no western cartoon style, no 3D, no photorealistic, no deformed hands"
}
```

### 🧸 3D / Pixar / CGI

```json
{
  "instruction": "",
  "subject": {
    "character": "",
    "material": "",
    "proportions": "",
    "expression": "",
    "pose": ""
  },
  "scene": {
    "environment": "",
    "props": "",
    "scale": ""
  },
  "render": {
    "engine": "",
    "style": "",
    "materials": "",
    "lighting": "",
    "effects": ""
  },
  "mood": "",
  "color_palette": "",
  "aspect_ratio": "16:9",
  "quality": "3D render, Pixar quality, high detail, raytraced, 8K",
  "negative": "no 2D, no flat, no sketch, no watermark, no text"
}
```

### 🎨 Watercolor / Traditional Art

```json
{
  "instruction": "",
  "subject": {
    "description": "",
    "details": ""
  },
  "scene": {
    "setting": "",
    "elements": ""
  },
  "traditional_art": {
    "medium": "",
    "paper": "",
    "technique": "",
    "brush": "",
    "finish": ""
  },
  "composition": {
    "framing": "",
    "white_space": ""
  },
  "mood": "",
  "color_palette": "",
  "aspect_ratio": "3:2",
  "quality": "fine art quality, museum worthy, masterful brushwork, visible texture",
  "negative": "no digital look, no photorealistic, no text, no watermark, no AI artifacts"
}
```

### ✏️ Minimalist / Graphic Design

```json
{
  "instruction": "",
  "subject": {
    "element": "",
    "style": ""
  },
  "design": {
    "approach": "",
    "grid": "",
    "shapes": "",
    "contrast": ""
  },
  "color_palette": "",
  "background": "",
  "aspect_ratio": "1:1",
  "quality": "clean vector quality, crisp edges, professional graphic design",
  "negative": "no photorealistic, no complex textures, no gradients unless specified, no text unless requested"
}
```

### 🌀 Surreal / Abstract

```json
{
  "instruction": "",
  "subject": {
    "central_element": "",
    "transformation": "",
    "symbolism": ""
  },
  "scene": {
    "reality_level": "",
    "environment": "",
    "scale_distortion": ""
  },
  "art_style": {
    "reference": "",
    "medium": "",
    "technique": ""
  },
  "mood": "",
  "color_palette": "",
  "aspect_ratio": "16:9",
  "quality": "highly detailed, surrealist masterpiece, museum quality",
  "negative": "no text, no watermark, no generic, no stock photo feel"
}
```

---

## Prompting Rules (ALL styles)

### Always Do:
1. **Be specific** — "mint-green gecko" not "a gecko", "warm golden hour" not "nice light"
2. **Include negative prompt** — always specify what to avoid
3. **Pick an aspect ratio** — match the content (landscape 16:9, portrait 9:16, square 1:1)
4. **Add sensory details** — textures, temperatures, sounds implied visually
5. **One focal point** — every image needs a clear subject
6. **Match quality keywords to style** — "8K photorealistic" for photos, "trending on ArtStation" for illustrations
7. **Color palette matters** — specify colors or a grading reference, don't leave it to chance

### Never Do:
1. ❌ Don't include text/words in the image (Gemini renders text poorly)
2. ❌ Don't over-specify (pick 1 camera, 1 lens, not 3 options)
3. ❌ Don't mix conflicting styles ("photorealistic anime" — pick one)
4. ❌ Don't use generic prompts ("a beautiful sunset" — add specifics)
5. ❌ Don't forget the negative prompt
6. ❌ Don't request NSFW content

### Resolution Guide:
- **1K** — Quick drafts, thumbnails, iteration
- **2K** — Social media, general use (best quality/cost ratio)
- **4K** — Print, hero images, final deliverables

---

## Examples

### User says: "make me a gecko eating pizza on a skateboard"

**Detected style:** 3D / Pixar (fun character scene)

```json
{
  "instruction": "A cute mint-green gecko character riding a skateboard while eating a large slice of pepperoni pizza",
  "subject": {
    "character": "small mint-green gecko with big expressive pale pink eyes and a wide happy grin",
    "material": "smooth glossy skin with subtle subsurface scattering",
    "proportions": "stylized chibi, slightly oversized head",
    "expression": "pure joy, eyes half-closed savoring the pizza",
    "pose": "standing on a moving skateboard, one hand holding pizza slice, cheese stretching"
  },
  "scene": {
    "environment": "sunny Venice Beach boardwalk, palm trees, blue sky",
    "props": "worn wooden skateboard with flame decals, pizza box on a nearby bench",
    "scale": "life-size character in real-world setting"
  },
  "render": {
    "engine": "Pixar RenderMan",
    "style": "Pixar",
    "materials": "subsurface scattering on gecko skin, glossy cheese, matte concrete",
    "lighting": "warm golden hour sunlight with soft shadows",
    "effects": "subtle motion blur on skateboard wheels, depth of field"
  },
  "mood": "carefree summer vibes, playful and fun",
  "color_palette": "warm yellows, mint green, sky blue, pizza orange",
  "aspect_ratio": "16:9",
  "quality": "3D render, Pixar quality, high detail, raytraced, 8K",
  "negative": "no 2D, no flat, no text, no watermark, no dark mood"
}
```

### User says: "a samurai in the rain, dramatic"

**Detected style:** Cinematic / Photorealistic

```json
{
  "instruction": "A lone samurai standing in heavy rain at night, katana drawn, cinematic and dramatic",
  "subject": {
    "description": "weathered samurai warrior, middle-aged, battle-scarred",
    "clothing": "dark indigo hakama and kimono, worn leather chest armor, straw sandals",
    "expression": "intense focus, eyes locked forward, jaw set",
    "pose": "standing in chudan-no-kamae stance, katana held at center",
    "details": "rain droplets on blade edge catching light, wet hair tied in topknot"
  },
  "scene": {
    "setting": "abandoned temple courtyard with stone lanterns",
    "key_elements": "heavy rainfall, puddles reflecting lantern light",
    "background": "dark silhouette of temple roof, mist rolling between pillars",
    "foreground": "rain splashing on stone ground, shallow puddles",
    "time_of_day": "deep night, moonless"
  },
  "photography": {
    "camera": "ARRI Alexa 65",
    "lens": "50mm f/1.2",
    "shot_type": "medium shot, slightly low angle",
    "depth_of_field": "shallow, rain drops in foreground out of focus",
    "lighting": "single warm lantern as key light from left, cool rain backlit by distant light, rim light on shoulders",
    "film_stock": "CineStill 800T",
    "texture": "subtle film grain"
  },
  "mood": "tense calm before the storm, honor and solitude",
  "color_palette": "deep indigo, warm amber lantern glow, cool steel grey",
  "aspect_ratio": "16:9",
  "quality": "8K, photorealistic, cinematic, RAW photo",
  "negative": "no text, no watermark, no deformed faces, no blurry, no anime style"
}
```

### User says: "paint me some sunflowers, like watercolor"

**Detected style:** Watercolor / Traditional

```json
{
  "instruction": "A loose, expressive watercolor painting of sunflowers in a ceramic vase",
  "subject": {
    "description": "five sunflowers in various stages of bloom, some drooping slightly",
    "details": "petals ranging from bright yellow to burnt sienna, dark brown seed heads with visible texture"
  },
  "scene": {
    "setting": "simple tabletop, implied window light",
    "elements": "rustic blue ceramic vase, a few fallen petals on the surface, soft shadow"
  },
  "traditional_art": {
    "medium": "watercolor",
    "paper": "cold press watercolor paper, visible tooth texture",
    "technique": "wet-on-wet for soft petal edges, dry brush for seed head texture, controlled wash for background",
    "brush": "large round for washes, small round for details",
    "finish": "loose and expressive, some areas left unfinished showing white paper"
  },
  "composition": {
    "framing": "slightly off-center, flowers extending above frame edge",
    "white_space": "generous margins, breathing room around the vase"
  },
  "mood": "warm, nostalgic, peaceful afternoon light",
  "color_palette": "cadmium yellow, burnt sienna, cerulean blue, sap green — limited palette",
  "aspect_ratio": "3:2",
  "quality": "fine art quality, museum worthy, masterful brushwork, visible paper texture",
  "negative": "no digital look, no photorealistic, no text, no watermark, no harsh edges"
}
```

---

## Editing / Reference Images

When the user provides a reference image to edit or use as inspiration:

1. **Include the image** with `-i` flag
2. **Describe what to change** in the instruction field
3. **Keep the JSON structure** — same style detection and template applies
4. **Be explicit** about what to preserve vs change

```bash
uv run {nano-banana-pro-dir}/scripts/generate_image.py \
  --prompt '' \
  --filename "edited-output.png" \
  -i "/path/to/original.png" \
  --resolution 2K
```

For character consistency across multiple images, always include the same reference image(s) and describe the character identically in the subject field.

---

## Quick Reference: Style → Key Fields

| Style | Must-Have Fields | Key Differentiator |
|-------|-----------------|-------------------|
| Cinematic | photography.camera, lens, film_stock | Real camera specs sell the realism |
| Product | photography.lighting, surface, reflections | Clean, commercial precision |
| Illustration | art_style.medium, technique, reference_artists | Artist references anchor the style |
| Anime | art_style.studio_reference, line_weight, shading | Studio name = instant style match |
| 3D/Pixar | render.engine, style, materials | Render engine + material physics |
| Watercolor | traditional_art.medium, paper, technique | Paper texture + brush technique |
| Minimalist | design.approach, shapes, contrast | Less is more, precision matters |
| Surreal | art_style.reference, reality_level, transformation | Named surrealist = instant vibe |

## Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [minilozio](https://github.com/minilozio)
- **Source:** [minilozio/nano-banana-prompting-skill](https://github.com/minilozio/nano-banana-prompting-skill)
- **License:** MIT

Install and usage instructions live in the source repository linked above.

## Pricing

- **Free** — Free

## Security capabilities

Automated source analysis of v0.1.0 — what this tool can access:

- **Network access:** no
- **Filesystem access:** no
- **Shell / process execution:** no
- **Environment & secrets:** no
- **Dynamic code execution:** no

*"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.*


## Versions

- **0.1.0** — security scan: passed — Imported from the upstream source.

## Links

- Listing page: https://agentstack.voostack.com/l/skill-minilozio-nano-banana-prompting-skill-nano-banana-prompting-skill
- Seller: https://agentstack.voostack.com/s/minilozio
- Browse the marketplace: https://agentstack.voostack.com/browse

---
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