Skill: wegoagain-dev/nano-banana-pro-fork (version 1.0.5)

--- name: nano-banana-pro description: Use Nano Banana 2 (Gemini 3.1 Flash Image), the newest image model focused on faster iteration, lower cost, and strong quality. Published 2026-02-26 as the latest Flash-image generation family update. Supports image generation/edit, image-to-image, and 1K/2K/4K. --- # Nano Banana 2 (Gemini 3.1 Flash Image) - Faster, lower-cost image generation & editing Generate new images or edit existing ones using Nano Banana 2 (`gemini-3.1-flash-image-preview`), Google’s newer image family that targets faster iterative generation and stronger price/performance balance while staying in the same image-editing workflow. ## Why Nano Banana 2 (Gemini 3.1 Flash Image) - **Newer release path:** Gemini 3.1 Flash Image is documented as the 26 Feb 2026 Flash-image family release (vs. Nano Banana Pro’s 20 Nov 2025 release date for image preview). - **Faster iteration:** Google docs position Gemini 3.1 Flash Image as optimized for image understanding/generation with a balance of price and performance. - **Cost focus:** It is marketed for lower-cost, faster iterative image generation workflows compared with older Pro-first quality-first defaults. - **Strong baseline quality:** It remains suitable for professional generation/editing and supports multi-image editing/multi-turn workflows in the same API flow. Use this as the default for drafts and quick turns; use higher-cost variants when you need a specific quality edge on a non-time-critical final pass. ## Usage Run the script using absolute path (do NOT cd to skill directory first): **Generate new image:** ```bash uv run ~/.codex/skills/nano-banana-pro/scripts/generate_image.py --prompt "your image description" --filename "output-name.png" [--resolution 1K|2K|4K] [--api-key KEY] ``` **Edit existing image:** ```bash uv run ~/.codex/skills/nano-banana-pro/scripts/generate_image.py --prompt "editing instructions" --filename "output-name.png" --input-image "path/to/input.png" [--resolution 1K|2K|4K] [--api-key KEY] ``` **Important:** Always run from the user's current working directory so images are saved where the user is working, not in the skill directory. ## Default Workflow (draft → iterate → final) Goal: fast iteration without burning time on 4K until the prompt is correct. - Draft (1K): quick feedback loop - `uv run ~/.codex/skills/nano-banana-pro/scripts/generate_image.py --prompt "<draft prompt>" --filename "yyyy-mm-dd-hh-mm-ss-draft.png" --resolution 1K` - Iterate: adjust prompt in small diffs; keep filename new per run - If editing: keep the same `--input-image` for every iteration until you’re happy. - Final (4K): only when prompt is locked - `uv run ~/.codex/skills/nano-banana-pro/scripts/generate_image.py --prompt "<final prompt>" --filename "yyyy-mm-dd-hh-mm-ss-final.png" --resolution 4K` ## Resolution Options The Nano Banana 2 / Gemini 3.1 Flash Image API supports three resolutions (uppercase K required): - **1K** (default) - ~1024px resolution - **2K** - ~2048px resolution - **4K** - ~4096px resolution Map user requests to API parameters: - No mention of resolution → `1K` - "low resolution", "1080", "1080p", "1K" → `1K` - "2K", "2048", "normal", "medium resolution" → `2K` - "high resolution", "high-res", "hi-res", "4K", "ultra" → `4K` ## API Key The script checks for API key in this order: 1. `--api-key` argument (use if user provided key in chat) 2. `GEMINI_API_KEY` environment variable If neither is available, the script exits with an error message. ## Preflight + Common Failures (fast fixes) - Preflight: - `command -v uv` (must exist) - `test -n \"$GEMINI_API_KEY\"` (or pass `--api-key`) - If editing: `test -f \"path/to/input.png\"` - Common failures: - `Error: No API key provided.` → set `GEMINI_API_KEY` or pass `--api-key` - `Error loading input image:` → wrong path / unreadable file; verify `--input-image` points to a real image - “quota/permission/403” style API errors → wrong key, no access, or quota exceeded; try a different key/account ## Filename Generation Generate filenames with the pattern: `yyyy-mm-dd-hh-mm-ss-name.png` **Format:** `{timestamp}-{descriptive-name}.png` - Timestamp: Current date/time in format `yyyy-mm-dd-hh-mm-ss` (24-hour format) - Name: Descriptive lowercase text with hyphens - Keep the descriptive part concise (1-5 words typically) - Use context from user's prompt or conversation - If unclear, use random identifier (e.g., `x9k2`, `a7b3`) Examples: - Prompt "A serene Japanese garden" → `2025-11-23-14-23-05-japanese-garden.png` - Prompt "sunset over mountains" → `2025-11-23-15-30-12-sunset-mountains.png` - Prompt "create an image of a robot" → `2025-11-23-16-45-33-robot.png` - Unclear context → `2025-11-23-17-12-48-x9k2.png` ## Image Editing When the user wants to modify an existing image: 1. Check if they provide an image path or reference an image in the current directory 2. Use `--input-image` parameter with the path to the image 3. The prompt should contain editing instructions (e.g., "make the sky more dramatic", "remove the person", "change to cartoon style") 4. Common editing tasks: add/remove elements, change style, adjust colors, blur background, etc. ## Prompt Handling **For generation:** Pass user's image description as-is to `--prompt`. Only rework if clearly insufficient. **For editing:** Pass editing instructions in `--prompt` (e.g., "add a rainbow in the sky", "make it look like a watercolor painting") Preserve user's creative intent in both cases. ## Prompt Templates (high hit-rate) Use templates when the user is vague or when edits must be precise. - Generation template: - “Create an image of: <subject>. Style: <style>. Composition: <camera/shot>. Lighting: <lighting>. Background: <background>. Color palette: <palette>. Avoid: <list>.” - Editing template (preserve everything else): - “Change ONLY: <single change>. Keep identical: subject, composition/crop, pose, lighting, color palette, background, text, and overall style. Do not add new objects. If text exists, keep it unchanged.” ## Output - Saves PNG to current directory (or specified path if filename includes directory) - Script outputs the full path to the generated image - **Do not read the image back** - just inform the user of the saved path ## Examples **Generate new image:** ```bash uv run ~/.codex/skills/nano-banana-pro/scripts/generate_image.py --prompt "A serene Japanese garden with cherry blossoms" --filename "2025-11-23-14-23-05-japanese-garden.png" --resolution 4K ``` **Edit existing image:** ```bash uv run ~/.codex/skills/nano-banana-pro/scripts/generate_image.py --prompt "make the sky more dramatic with storm clouds" --filename "2025-11-23-14-25-30-dramatic-sky.png" --input-image "original-photo.jpg" --resolution 2K ```


Security scan verdicts — ClawScan: clean | static analysis: clean | VirusTotal: clean | SkillSpector: clean (LOW)