Skillshub nano-banana-2

Generate and edit images using Google's Nano Banana 2 (Gemini 3.1 Flash Image Preview) API. This skill should be used when the user asks to create or modify images, especially when they need fast iteration, explicit aspect-ratio control, or resolution control from 512px to 4K.

install

source · Clone the upstream repo

git clone https://github.com/ComeOnOliver/skillshub

Claude Code · Install into ~/.claude/skills/

T=$(mktemp -d) && git clone --depth=1 https://github.com/ComeOnOliver/skillshub "$T" && mkdir -p ~/.claude/skills && cp -r "$T/skills/intellectronica/agent-skills/nano-banana-2" ~/.claude/skills/comeonoliver-skillshub-nano-banana-2-e3f809 && rm -rf "$T"

manifest: skills/intellectronica/agent-skills/nano-banana-2/SKILL.md

source content

Nano Banana 2 Image Generation & Editing

Generate new images or edit existing images with Nano Banana 2 (

gemini-3.1-flash-image-preview

Usage

Run the script using absolute or workspace-relative path (do NOT cd into the skill directory first):

Generate new image:

uv run ./.agents/skills/nano-banana-2/scripts/generate_image.py --prompt "your image description" --filename "output-name.png" [--resolution 512px|1K|2K|4K] [--aspect-ratio RATIO] [--api-key KEY]

Edit image(s) with references:

uv run ./.agents/skills/nano-banana-2/scripts/generate_image.py --prompt "editing instructions" --filename "output-name.png" --input-image "path/to/input1.png" [--input-image "path/to/input2.png" ...] [--resolution 512px|1K|2K|4K] [--aspect-ratio RATIO] [--api-key KEY]

Always run from the user's current working directory so outputs are saved in the active project context.

Model

Use model code:

```
gemini-3.1-flash-image-preview
```
(Nano Banana 2)

Do not use

gemini-3-pro-image-preview

in this skill.

Resolution Options

Nano Banana 2 supports:

```
512px
```
(fastest, low-latency iteration)
```
1K
```
(default)
```
2K
```
```
4K
```

Map common user language:

"quick draft", "thumbnail", "tiny", "512", "0.5K" →
```
512px
```
no resolution mention →
```
1K
```
"2K", "medium", "normal" →
```
2K
```
"4K", "high-res", "ultra", "print quality" →
```
4K
```

Use uppercase

for

1K

2K

4K

Aspect Ratios

Supported aspect ratios:

1:1

1:4

1:8

2:3

3:2

3:4

4:1

4:3

4:5

5:4

8:1

9:16

16:9

21:9

Map common requests:

square post / icon →
```
1:1
```
phone wallpaper / vertical reel →
```
9:16
```
widescreen / slide / hero image →
```
16:9
```
cinematic wide →
```
21:9
```
portrait print →
```
2:3
```
or
```
3:4
```
panorama banner →
```
4:1
```
or
```
8:1
```

If unspecified, let the model default behavior apply.

Reference Images (New in Gemini 3 Image workflows)

Provide up to 14 reference images when needed by repeating

--input-image

preserve character consistency
preserve object fidelity
combine multiple visual references into one output

Use one image for simple edits; use multiple images for composition or consistency-sensitive tasks.

API Key

Resolve API key in this order:

```
--api-key
```
argument
```
GEMINI_API_KEY
```
environment variable

If no key is available, stop and report a clear error.

Filename Generation

Generate filenames as:

yyyy-mm-dd-hh-mm-ss-name.png

Examples:

```
2026-02-26-17-31-04-japanese-garden.png
```
```
2026-02-26-17-31-59-social-banner.png
```

Prompt Handling

For generation, pass the user's request as-is unless critically underspecified. For editing, include explicit transformation instructions in the prompt and preserve the original intent.

Output

Save PNG to the current directory (or to a provided path in
```
--filename
```
)
Return the full saved path(s)
Do not read the output image back unless explicitly requested

Examples

Create a 4K widescreen image:

uv run ./.agents/skills/nano-banana-2/scripts/generate_image.py --prompt "Futuristic city skyline at blue hour with neon reflections" --filename "2026-02-26-17-45-00-futuristic-skyline.png" --resolution 4K --aspect-ratio 16:9

Edit with multiple references:

uv run ./.agents/skills/nano-banana-2/scripts/generate_image.py --prompt "Create a polished campaign image that keeps the exact logo details and character identity" --filename "2026-02-26-17-50-10-campaign-image.png" --input-image "logo.png" --input-image "character.png" --resolution 2K --aspect-ratio 4:5