nano-banana

Nano Banana Skill

Python scripting with Gemini image generation using uv. Write small, focused scripts using heredocs for quick tasks—no files needed for one-off operations.

Choosing Your Approach

Quick image generation: Use heredoc with inline Python for one-off image requests.

Complex workflows: When multiple steps are needed (generate -> refine -> save), break into separate scripts and iterate.

Scripting tasks: For non-image Python tasks, use the same heredoc pattern with uv run.

Writing Scripts

Execute Python inline using heredocs with inline script metadata for dependencies:

uv run - << 'EOF'
# /// script
# dependencies = ["google-genai", "pillow"]
# ///
from google import genai
from google.genai import types

client = genai.Client()

response = client.models.generate_content(
    model="gemini-3-pro-image-preview",
    contents=["A cute banana character with sunglasses"],
    config=types.GenerateContentConfig(
        response_modalities=['IMAGE']
    )
)

for part in response.parts:
    if part.inline_data is not None:
        image = part.as_image()
        image.save("tmp/generated.png")
        print("Image saved to tmp/generated.png")
EOF

The # /// script block declares dependencies inline using TOML syntax. This makes scripts self-contained and reproducible.

Why these dependencies:

• google-genai - Gemini API client
• pillow - Required for .as_image() method (converts base64 to PIL Image) and saving images

Only write to files when:

• The script needs to be reused multiple times
• The script is complex and requires iteration
• The user explicitly asks for a saved script

Basic Template

uv run - << 'EOF'
# /// script
# dependencies = ["google-genai", "pillow"]
# ///
from google import genai
from google.genai import types

client = genai.Client()

# Generate image
response = client.models.generate_content(
    model="gemini-3-pro-image-preview",
    contents=["YOUR PROMPT HERE"],
    config=types.GenerateContentConfig(
        response_modalities=['IMAGE']
    )
)

# Save result
for part in response.parts:
    if part.text is not None:
        print(part.text)
    elif part.inline_data is not None:
        image = part.as_image()
        image.save("tmp/output.png")
        print("Saved: tmp/output.png")
EOF