Gemini Nanobanana

Documents

gemini-nanobanana

Gemini Nanobanana is an Agent Skill for documents published in the duotify/GitHubClawToolkit repository on GitHub: a SKILL.md instruction file an AI agent can load to do this task.

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.

View on GitHub ↗

QUICK START

How to use this skill

Bring this guide into your coding agent with a prompt tailored to the tool you use.

Open your project in Codex.
Copy and paste the prompt below.
Review files and risks before approving any action.

Prompt to paste

Inspect the Agent Skill at https://github.com/duotify/GitHubClawToolkit/blob/HEAD/templates/copilot-gemini-api/.agents/skills/gemini-nanobanana/SKILL.md and all supporting files. Report provenance, permissions, scripts, dependencies, and security risks. Propose an exact installation into .agents/skills/gemini-nanobanana, but wait for my approval before writing files or running scripts.

Copying this prompt does not install or run the skill. Review third-party files before use.

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:

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.