gemini-nanobanana

name	gemini-nanobanana
description	Use this skill when users ask to generate, edit, or compose images with Nano Banana (Gemini image models), including text-to-image, image editing, multi-image composition, grounding, and output sizing/saving controls.

Do this first

• Use a Node.js wrapper (@google/genai) as the primary flow (multi-turn edits, grounding, advanced generationConfig).
• Use scripts/gemini-nanobanana-cli.js for quick single-turn generation/editing runs.
• Do not teach raw curl; keep guidance in JS CLI/wrapper form.

Enforce these defaults

• API key source: NANOBANANA_GEMINI_API_KEY with fallback GEMINI_API_KEY.
• Default model: gemini-3.1-flash-image-preview (allow env override via NANOBANANA_MODEL).
• Reference images: support up to 14 total.
• Thinking strength: configurable (minimal|low|medium|high), default High.
• Aspect ratio: default Auto.
• Resolution: default 1K.
• Output mode: default Images only.
• Google Search grounding tool: default Disabled; enable with --google-search when needed.
• Output directory: default nanobanana-output/, unless the prompt explicitly asks for another location.
• 512px rule: send imageConfig.imageSize as string "512" in API calls (never numeric 512).

Read references intentionally

• Start in references\image-generation-api.md for operational payload rules, model behavior, sizing, thinking, grounding, and limits.
• Use references\sources.md to verify source provenance and jump to upstream docs.
• For canonical API behavior, read:
  • Gemini image-generation docs
  • Aspect ratios and image size
  • Thinking process
  • Grounding with Google Search
  • Grounding with Google Image Search

Output formatting rules

• After successful generation, always report results in this format:
  1. A short completion message (e.g. ✅ 圖片已產出)
  2. The relative path to each generated file, formatted as a markdown image embed: ![description](relative/path/to/image.jpg)
  3. File metadata: format (JPEG/PNG), dimensions, file size
• Example final answer:

  ✅ 圖片已產出
  
  ![一杯抹茶拿鐵](workspaces/issue-2/nanobanana-output/matcha-latte-01.jpg)
  
  - 格式：JPEG · 1408×768 · 757 KB
  

• This ensures downstream systems (GitHub Issue comments, Telegram relay) can display or link to the image.

Execution pattern

• Default to Node.js wrapper flows for regular usage, especially when payload control is needed.
• Quick path (agent runs from workspaces/issue-N/; resolve the repo root first):
  • REPO_ROOT=$(git rev-parse --show-toplevel 2>/dev/null || echo "../..") then node "$REPO_ROOT/.agents/skills/gemini-nanobanana/scripts/gemini-nanobanana-cli.js" --prompt "..."
  • Add references via repeated -i/--image (up to 14).
  • Enable grounding via --google-search when prompt needs fresh web context.
• The API key (GEMINI_API_KEY / NANOBANANA_GEMINI_API_KEY) is injected by the workflow environment; do not hardcode it. The CLI reads it automatically from the environment.