nano-banana-pro

Nano Banana Pro (Gemini Image Generation)

Use the bundled script to generate or edit images with selectable models.

Available Models

Model ID	Alias	Description
`gemini-3.1-flash-image-preview`	`flash`	Nano Banana 2 — fast, good quality (default)
`gemini-3-pro-image-preview`	`pro`	Nano Banana Pro — high quality, supports 2K/4K, up to 14 input images

Default model: gemini-3.1-flash-image-preview (alias flash)

Usage

Generate

uv run {baseDir}/scripts/generate_image.py --prompt "your image description" --filename "output.png"

Generate with model selection

uv run {baseDir}/scripts/generate_image.py --prompt "your image description" --filename "output.png" --model flash
uv run {baseDir}/scripts/generate_image.py --prompt "your image description" --filename "output.png" --model pro

Generate with resolution, aspect ratio, and proxy

uv run {baseDir}/scripts/generate_image.py --prompt "a landscape" --filename "output.png" --model pro --resolution 2K --aspect-ratio 16:9
uv run {baseDir}/scripts/generate_image.py --prompt "a landscape" --filename "output.png" --proxy http://127.0.0.1:7890

Edit (single image)

uv run {baseDir}/scripts/generate_image.py --prompt "edit instructions" --filename "output.png" -i "/path/in.png" --model pro --resolution 2K

Multi-image composition (up to 14 images, pro model)

uv run {baseDir}/scripts/generate_image.py --prompt "combine these into one scene" --filename "output.png" --model pro -i img1.png -i img2.png -i img3.png

API key

GEMINI_API_KEY env var
Or set skills."nano-banana-pro".apiKey / skills."nano-banana-pro".env.GEMINI_API_KEY in ~/.openclaw/openclaw.json

Proxy

HTTPS_PROXY env var (in .env or system environment)
Or pass --proxy http://127.0.0.1:7890 on the command line

Notes

Resolutions: 1K (default), 2K, 4K (only pro model supports 4K).
Aspect ratios: 1:1 (default), 16:9, 9:16, 4:3, 3:4.
Use timestamps in filenames: yyyy-mm-dd-hh-mm-ss-name.png.
The script prints a MEDIA: line for OpenClaw to auto-attach on supported chat providers.
Do not read the image back; report the saved path only.