Nano Banana Use

Use this skill to generate, edit, and compose images using Gemini's Nano Banana models (

gemini-2.5-flash-image

and

gemini-3-pro-image-preview

).

This skill uses portable Python scripts managed by

uv

.

Prerequisites

Ensure you have one of the following authentication methods configured in your environment:

API Key

:

GOOGLE_API_KEY

or

GEMINI_API_KEY

Vertex AI

:

GOOGLE_CLOUD_PROJECT

GOOGLE_CLOUD_LOCATION

GOOGLE_GENAI_USE_VERTEXAI=1

Usage

Generate an Image

Step 1: Confirm Parameters

Before running the script, confirm the following parameters with the user or state the defaults you will use:

Prompt

The image description.

Model

Default is

gemini-3-pro-image-preview

.

Aspect Ratio

Default is

1:1

.

Safety Filter

Default is

BLOCK_MEDIUM_AND_ABOVE

.

Step 2: Run the Script

Run the python script using

uv

:

uv run skills/nano-banana-use/scripts/generate_image.py

"A futuristic banana city"

--output

city.png

Edit an Image

Modify an existing image based on a text prompt.

uv run skills/nano-banana-use/scripts/edit_image.py original.png

"Make the sky purple"

--output

edited.png

Compose Images

Generate a new image based on multiple input images and a prompt.

uv run skills/nano-banana-use/scripts/compose_image.py

--image

style.png

--image

subject.jpg

"A painting of the subject in the style of the first image"

--output

composition.png

Options

prompt

The text description of the image.

--model

The model to use. Defaults to

gemini-3-pro-image-preview

.

--output

The filename for the saved image. Defaults to

generated_image.png

.

--aspect-ratio

The aspect ratio of the generated image. Defaults to

1:1

. Supported:

1:1

,

16:9

,

4:3

,

3:4

,

9:16

.

--safety-filter-level

Safety filter threshold. Defaults to BLOCK_MEDIUM_AND_ABOVE .