Generate Images with Nano Banana Pro

Copy Install a global Claude Code skill called "nano-banana". Do all of the following: 1. Create the directory: ~/.claude/skills/nano-banana/scripts/ 2. Write the file ~/.claude/skills/nano-banana/SKILL.md with EXACTLY the content between the SKILL_START and SKILL_END markers (do not include the markers): ===SKILL_START=== --- name: nano-banana description: Generate an image from a text description using Google's Nano Banana Pro (Gemini 3 Pro Image) via the Gemini API. Use whenever the user asks to generate, create, make, or draw an image, picture, logo, illustration, or artwork from a text prompt. Requires a GEMINI_API_KEY with billing enabled (Nano Banana Pro is a paid model). --- # Nano Banana Pro Image Generator Generates a single image from a text prompt using the Gemini API model `gemini-3-pro-image-preview` (Google's "Nano Banana Pro") and saves it to a PNG file. ## When to use Trigger this skill when the user asks to generate, create, make, or draw an image, picture, logo, illustration, or artwork from a text description. ## Requirements - `GEMINI_API_KEY` in the environment. Create one at https://aistudio.google.com/apikey - Nano Banana Pro is a PAID model (no free API tier as of 2026), so billing must be enabled on the key's Google project. Roughly $0.13 per image. - Python packages: `google-genai`, `Pillow` ## How to run Run the bundled script with a prompt and, optionally, an output path and aspect ratio: python3 ~/.claude/skills/nano-banana/scripts/generate.py "<prompt>" [output.png] [aspect_ratio] Examples: python3 ~/.claude/skills/nano-banana/scripts/generate.py "a cozy coffee shop on a rainy evening, watercolor" coffee.png 16:9 python3 ~/.claude/skills/nano-banana/scripts/generate.py "a minimalist flat-vector logo of a fox" fox.png 1:1 ## Tips - Write the prompt as a full sentence describing the subject, style, lighting, and mood. Narrative prompts beat keyword lists. - Default aspect ratio is 1:1. Pass 16:9, 9:16, 4:3, etc. as the third argument. - Output is saved as a PNG at 2K resolution. ## Free alternative To test without billing, edit scripts/generate.py and change MODEL to gemini-2.5-flash-image (standard Nano Banana), which has a free daily quota. Quality is lower than Pro. ===SKILL_END=== 3. Write the file ~/.claude/skills/nano-banana/scripts/generate.py with EXACTLY the content between the PY_START and PY_END markers (do not include the markers): ===PY_START=== import os import sys from io import BytesIO MODEL = "gemini-3-pro-image-preview" # Nano Banana Pro. Change to gemini-2.5-flash-image for the free tier. def main(): args = sys.argv[1:] if not args: print('Usage: generate.py "<prompt>" [output.png] [aspect_ratio]') sys.exit(1) prompt = args[0] out = args[1] if len(args) > 1 else "image.png" aspect = args[2] if len(args) > 2 else "1:1" key = os.getenv("GEMINI_API_KEY") if not key: print("GEMINI_API_KEY is not set. Create one at https://aistudio.google.com/apikey") sys.exit(1) try: from google import genai from google.genai import types from PIL import Image except ImportError: print("Missing dependencies. Run: python3 -m pip install google-genai Pillow") sys.exit(1) client = genai.Client(api_key=key) try: resp = client.models.generate_content( model=MODEL, contents=[prompt], config=types.GenerateContentConfig( response_modalities=["TEXT", "IMAGE"], image_config=types.ImageConfig(aspect_ratio=aspect, image_size="2K"), ), ) except Exception as e: print("Image generation failed:", e) print("If this is a billing or quota error, Nano Banana Pro needs billing enabled.") sys.exit(1) for part in resp.candidates[0].content.parts: if getattr(part, "inline_data", None) and part.inline_data.data: Image.open(BytesIO(part.inline_data.data)).save(out) print("Saved image to", out) return print("No image was returned.") sys.exit(1) main() ===PY_END=== 4. Install the Python dependencies by running: python3 -m pip install google-genai Pillow 5. Verify both files exist, then print "nano-banana installed". If GEMINI_API_KEY is not set in my environment, remind me to set it.

Copy Use the nano-banana skill to generate an image of a cozy coffee shop on a rainy evening, warm light in the windows, watercolor style. Save it as coffee.png at 16:9.