# Generate Image > This skill should be used when the user asks to "generate an image", "create a banner", "make artwork", "create an illustration", "generate a logo", "make a graphic", "design a header", "AI art", "img2img", "social share image", "OG image", "open graph image", "Twitter card", "hero image", "cover photo", "profile picture", "social media graphic", or needs AI image generation. Handles prompt rewriting and Gemini 3 Pro image generation API calls. - Skill: `b-open-io/generate-image` (Agent Skill, multi-file: 4 files) - Install (CLI): `npx skillmds@latest add b-open-io/generate-image` - Raw SKILL.md: https://api.skillmd.com/api/skills/b-open-io/generate-image/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Design & Media - Author: b-open-io (https://skillmd.com/u/b-open-io) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/b-open-io/generate-image --- # Generate Image Generate images using Nano Banana Pro (`gemini-3-pro-image`). ## When to Use Use this skill when the user asks to: - Generate an image from a text prompt - Create artwork, illustrations, or graphics - Generate variations of an existing image (img2img) - Create scenes with multiple reference images (character + location + other characters) ## Style Selection **If the user hasn't specified a style**, present a multi-choice question before proceeding: > **How would you like to handle the art style?** > > 1. **Pick a style** - Browse 167 styles visually and choose one > 2. **Let me choose** - I'll suggest a style based on your prompt > 3. **What are styles?** - Learn how the style system works > 4. **No style** - Generate without a specific art style Use the `AskUserQuestion` tool to present this choice. **If the user picks "Pick a style"**, launch the style picker (pick mode is the default): ```bash STYLE_JSON=$(bun run --cwd ${CLAUDE_PLUGIN_ROOT} ${CLAUDE_PLUGIN_ROOT}/skills/browsing-styles/scripts/preview_server.ts) ``` The picker opens a browser. The user clicks a style, views the detail modal, clicks "Select This Style". `STYLE_JSON` receives the selection as JSON and the server exits. Parse the `id` field and pass it via `--style ` to the generate command. **If the user picks "Let me choose"**, select the most fitting style based on their prompt and explain why. Use the style suggestions in the "Suggest Styles to Users" section below. **If the user picks "What are styles?"**, explain: there are 167 curated art styles across 10 categories (traditional, digital, illustration, photography, design, retro, technique, decorative, creative, cultural). Each style includes prompt hints and a visual reference tile that gets sent to Gemini for better adherence. Then re-ask the style question. **If the user already specified a style** (e.g. "generate in watercolor style"), skip this step entirely and use `--style` directly. ## Gather Design Direction First **Ask clarifying questions before rewriting prompts** to understand the user's intent: 1. **Purpose**: What is the image for? (banner, logo, social media, product shot, art piece) 2. **Color palette**: Any brand colors? Dark/light theme? Specific mood? 3. **Composition constraints**: Aspect ratio needs? Text overlay space? Full-bleed vs bordered? 4. **Key elements**: What must be included? What should be avoided? Simple requests like "make a cat image" can proceed with sensible defaults. Complex requests like "create a banner for my app" require clarification to avoid iteration waste. ## Prompt Rewriting (Critical) **Before generating any image, always rewrite the user's prompt** using the guide in `references/prompt-guide.md`. The core principle: **"Describe the scene, don't just list keywords."** ### Rewriting Checklist Transform simple prompts by adding: 1. **Subject details**: Specific appearance, clothing, expression, materials 2. **Environment/Setting**: Location, time of day, weather, indoor/outdoor 3. **Lighting**: Natural/artificial, direction, quality, color temperature 4. **Composition**: Camera angle, distance, framing, focal length 5. **Style/Aesthetic**: Photorealistic, illustration style, art movement 6. **Mood/Atmosphere**: Emotional tone, color palette mood 7. **Technical specs**: Aspect ratio, level of detail, textures ### Example Transformation **User says**: "banner for my app" **Rewritten prompt**: "A modern, full-bleed banner for a technology application. Dark gradient background transitioning from deep navy to black. Abstract geometric network visualization with glowing nodes connected by thin lines. Clean sans-serif typography positioned left of center. Professional, tech-forward aesthetic with no visible borders or edges - the design extends seamlessly to all edges. 16:9 aspect ratio." **User says**: "a cat" **Rewritten prompt**: "A fluffy orange tabby cat lounging on a sun-drenched windowsill, soft afternoon light creating a warm glow on its fur. The cat is in a relaxed pose with half-closed eyes, conveying contentment. Shot from a low angle with shallow depth of field, the background showing a blurred garden view. Photorealistic, warm color palette." ## Recommended Workflow **Draft → Iterate → Final** approach saves time and API costs: 1. **Draft Phase (1K)**: Generate quickly at default resolution to test prompts 2. **Iteration Phase**: Refine prompts incrementally, creating new files each attempt 3. **Final Phase (4K)**: Only produce high-res output after prompt is validated **Do not read the image back** - the script outputs only the file path. This allows efficient iteration without Claude loading large image data. ## Usage ```bash bun run --cwd ${CLAUDE_PLUGIN_ROOT} ${CLAUDE_PLUGIN_ROOT}/skills/generate-image/scripts/generate.ts "prompt" [options] ``` ### Options - `--input ` - Reference image (can specify multiple times, up to 14 images) - `--style ` - Apply style from the style library (see browsing-styles skill) - `--size <1K|2K|4K>` - Image size (default: 1K for fast drafts) - `--aspect ` - Aspect ratio: 1:1, 16:9, 9:16, 4:3, 3:4 - `--negative ` - Negative prompt (what to avoid) - `--count ` - Number of images (1-4, default: 1) - `--guidance ` - Guidance scale - `--seed ` - Random seed for reproducibility - `--output ` - Output path - `--transparent` - Transparent/alpha background (OpenAI `background=transparent`; also Gemini) - `--provider ` - `gemini`, `openai`, or `xai`. Omit to **auto-pick** the best available provider for the request (see Models). - `--model ` - OpenAI Image 2.5 variant: `flare` / `gpt-image-2.5-flare` (default) or `sunburst` / `gpt-image-2.5-sunburst`. Sets provider to openai. Legacy provider aliases `gemini|openai|xai|grok` still work but are deprecated — use `--provider`. ### Examples ```bash # Simple generation bun run --cwd ${CLAUDE_PLUGIN_ROOT} ${CLAUDE_PLUGIN_ROOT}/skills/generate-image/scripts/generate.ts "cyberpunk cityscape at night" # With art style (100+ available, use short names or full IDs) bun run --cwd ${CLAUDE_PLUGIN_ROOT} ${CLAUDE_PLUGIN_ROOT}/skills/generate-image/scripts/generate.ts "mountain landscape" --style impressionism bun run --cwd ${CLAUDE_PLUGIN_ROOT} ${CLAUDE_PLUGIN_ROOT}/skills/generate-image/scripts/generate.ts "portrait" --style ukiy bun run --cwd ${CLAUDE_PLUGIN_ROOT} ${CLAUDE_PLUGIN_ROOT}/skills/generate-image/scripts/generate.ts "city street" --style noir # High-res with specific aspect ratio bun run --cwd ${CLAUDE_PLUGIN_ROOT} ${CLAUDE_PLUGIN_ROOT}/skills/generate-image/scripts/generate.ts "mountain landscape" --size 4K --aspect 16:9 # With negative prompt bun run --cwd ${CLAUDE_PLUGIN_ROOT} ${CLAUDE_PLUGIN_ROOT}/skills/generate-image/scripts/generate.ts "portrait of a cat" --negative "low quality, blurry" # Combine style with other options bun run --cwd ${CLAUDE_PLUGIN_ROOT} ${CLAUDE_PLUGIN_ROOT}/skills/generate-image/scripts/generate.ts "cat sleeping" --style wtrc --size 4K --aspect 1:1 # Generate multiple variations bun run --cwd ${CLAUDE_PLUGIN_ROOT} ${CLAUDE_PLUGIN_ROOT}/skills/generate-image/scripts/generate.ts "abstract art" --count 4 # Single reference image (img2img) bun run --cwd ${CLAUDE_PLUGIN_ROOT} ${CLAUDE_PLUGIN_ROOT}/skills/generate-image/scripts/generate.ts "make it look like a watercolor painting" --input photo.jpg # Multiple reference images (character consistency, scene composition) bun run --cwd ${CLAUDE_PLUGIN_ROOT} ${CLAUDE_PLUGIN_ROOT}/skills/generate-image/scripts/generate.ts "King on throne in dramatic lighting" \ --input character.png \ --input throne-room.png \ --aspect 16:9 --size 2K # Multiple characters in a scene bun run --cwd ${CLAUDE_PLUGIN_ROOT} ${CLAUDE_PLUGIN_ROOT}/skills/generate-image/scripts/generate.ts "Two warriors facing each other in combat" \ --input warrior1.png \ --input warrior2.png \ --input battlefield.png \ --aspect 16:9 ``` ## Multiple Reference Images Gemini supports up to 14 reference images per request: - **6 objects** - Locations, items, environments - **5 humans** - Character consistency across generations - Use detailed prompts describing how reference images should be combined - Reference images help maintain consistency across scene generations ## Common Formats | Format | Aspect Ratio | Recommended Size | Crop Target | |--------|-------------|-----------------|-------------| | OG / Social Share | 16:9 | 2K | 1200x630 via sips | | Twitter Card | 16:9 | 2K | 1200x628 via sips | | Hero Banner | 16:9 | 4K | Full width | | Profile Picture | 1:1 | 1K | 512x512 or 1024x1024 | | Story / Reel | 9:16 | 2K | 1080x1920 | | Team Lineup | 21:9 | 2K | Full width | ### Social Share Image Workflow **All 4 steps are required. Do not skip optimization.** 1. **Generate** at 16:9 with center-weighted prompt at `--size 2K` (retina-ready): ```bash bun run --cwd ${CLAUDE_PLUGIN_ROOT} ${CLAUDE_PLUGIN_ROOT}/skills/generate-image/scripts/generate.ts "CENTER all important elements, no content near edges. [your prompt]" --aspect 16:9 --size 2K --output social-share.png ``` 2. **Crop** to exact platform dimensions: ```bash sips -z 630 1200 -c 630 1200 social-share.png --out social-share-og.png # OG sips -z 628 1200 -c 628 1200 social-share.png --out social-share-tw.png # Twitter ``` 3. **Optimize** - convert to JPEG at 85% quality (social images never need transparency): ```bash sips -s format jpeg -s formatOptions 85 social-share-og.png --out social-share-og.jpg ``` 4. **Verify** dimensions and file size: ```bash sips -g pixelWidth -g pixelHeight social-share-og.jpg ls -la social-share-og.jpg # Target: <500KB ``` **Why optimize?** Gemini outputs PNG (~1-2MB). JPEG at 85% reduces to ~200-400KB with no visible quality loss. Social platforms re-compress uploads, so starting with a well-optimized JPEG prevents double-compression artifacts. ## Available Styles 100+ styles across 9 categories: traditional art, digital, illustration, photography, design/UI, retro, techniques, decorative, and creative/material-based. When a style has a tile reference image (`assets/tiles/.png`), it is automatically sent as a visual reference to Gemini alongside the prompt hints — this produces much better style adherence. ### Suggest Styles to Users When generating images, proactively suggest relevant styles: - For landscapes: `impr`, `roma`, `wtrl`, `cine` - For portraits: `barq`, `prer`, `anim`, `fnoi` - For UI/web: `brut`, `nbrt`, `glas`, `flat` - For retro/vintage: `y2k`, `frug`, `psyc`, `koda` - For whimsical/fun: `ghbl`, `kawa`, `chld`, `brit` - For dramatic: `cybr`, `nnoi`, `surr`, `expr` - For creative: `sand`, `undr`, `orig`, `clay`, `lego` Browse all: `bun run --cwd ${CLAUDE_PLUGIN_ROOT} ${CLAUDE_PLUGIN_ROOT}/skills/browsing-styles/scripts/list_styles.ts --table` Search: `bun run --cwd ${CLAUDE_PLUGIN_ROOT} ${CLAUDE_PLUGIN_ROOT}/skills/browsing-styles/scripts/list_styles.ts --search "watercolor"` ## Models & Providers Three providers, selected with `--provider` or **auto-picked** when omitted. | Provider | Model | Key | Strengths | Can't do | |----------|-------|-----|-----------|----------| | `gemini` (default fallback) | `gemini-3-pro-image` (Nano Banana Pro) | `GEMINI_API_KEY` | Style tiles, up to 14 reference images, dedicated negative prompts, **transparency**, 1K/2K/4K | — | | `openai` | **`gpt-image-2.5-flare`** (Flare, default) / **`gpt-image-2.5-sunburst`** (Sunburst, `--model sunburst`) | `OPENAI_API_KEY` | Best **in-image text**, lighting/textures, complex instructions, detailed layouts, **transparent backgrounds**, custom sizes, **image-to-image** (`--input`, up to 16, via the edits endpoint) | No style tiles, no dedicated negative param | | `xai` | `grok-imagine-image-quality` | `XAI_API_KEY` | Fast, spicier; good when Gemini's filter blocks a benign prompt | Text-to-image only — no img2img/tiles/negative | ### Auto-pick (default when `--provider` is omitted) The script chooses the **best provider whose key is present and that supports what the request needs**. Ranking is `openai > gemini > xai`. `--input` (img2img / reference images) is supported by **both openai and gemini** — openai routes it through the Image 2.5 edits endpoint, gemini through Nano Banana Pro (which also supports style tiles + up to 14 refs). So img2img auto-picks openai when its key is present; pass `--provider gemini` for Gemini's style-tile / multi-ref compositing. `--transparent` is supported by **openai and gemini** (OpenAI passes `background=transparent`). Capability gating still forces **Gemini** when the request uses `--style` (style tiles) or `--negative` (a dedicated negative parameter) — only Gemini supports those. Pin a default with `/gemskills:setup` or `GEMSKILLS_IMAGE_PROVIDER`. When openai is chosen with a `--style`, the style **tile image** is dropped (the textual hints are still applied) and `--negative` is folded into the prompt as an `Avoid: …` clause. xAI additionally drops reference images (text-to-image only). ### Prompt templates (tune per provider) Each provider parses prompts differently. **After the provider is resolved, read the matching guide and rewrite the prompt to it:** - `providers/prompts/image.gemini.md` - `providers/prompts/image.openai.md` - `providers/prompts/image.xai.md` ```bash # Force a provider / Image 2.5 variant bun run --cwd ${CLAUDE_PLUGIN_ROOT} ${CLAUDE_PLUGIN_ROOT}/skills/generate-image/scripts/generate.ts "neon city street, rain" --provider openai --size 4K bun run --cwd ${CLAUDE_PLUGIN_ROOT} ${CLAUDE_PLUGIN_ROOT}/skills/generate-image/scripts/generate.ts "app icon, rounded square" --model sunburst --transparent bun run --cwd ${CLAUDE_PLUGIN_ROOT} ${CLAUDE_PLUGIN_ROOT}/skills/generate-image/scripts/generate.ts "watercolor fox" --provider xai ``` > Models verified live: September 2026 (`gpt-image-2.5-flare`, `gpt-image-2.5-sunburst`, `grok-imagine-image-quality`, `gemini-3-pro-image`). If a newer generation exists, STOP and suggest a PR to `b-open-io/gemskills`. ## Reference Files For detailed prompting strategies and techniques: - **`references/prompt-guide.md`** - Comprehensive Gemini prompting guide with 7 strategies, example transformations, and best practices from Google's official documentation - **ask-gemini skill's `references/gemini-api.md`** - Current Gemini models, SDK info, and dynamic documentation via llms.txt