---
id: nexu-io/nexu/nano-banana
version: "314f5764"
license: MIT
install: manual
updated: 2026-04-26
---

# nano-banana — Nano Banana creates images from text descriptions using three selectable models—pick the standard version for speed, pro for top quality, or legacy for compatibility. The skill also edits existing images and combines multiple images into compositions, with automatic compression for large inputs.

Publisher: nexu-io · Stars: 3230 · Updated: 2026-04-26

Install (manual): `git clone https://github.com/nexu-io/nexu`

## SKILL.md

# Nano Banana — Image Generation

Image generation script supporting three models. Requires `sharp` for input image compression (auto-installed on first run).

## Models

| Flag | Notes |
|------|-------|
| `--model nano-banana` | **Default.** Fast, good quality. |
| `--model nano-banana-pro` | Highest quality, slower. |
| `--model nano-banana-2` | Legacy model. |

## Generate an image

```bash
node {baseDir}/scripts/generate-image.js --prompt "a cat sitting on mars" --filename "cat-on-mars.png"
```

## Edit a single image

```bash
node {baseDir}/scripts/generate-image.js \
  --prompt "make the sky purple" \
  --filename "edited.png" \
  -i "/path/to/input.png" \
  --model nano-banana-pro
```

## Multi-image composition (up to 14 images)

```bash
node {baseDir}/scripts/generate-image.js \
  --prompt "combine these into a collage" \
  --filename "collage.png" \
  -i img1.png -i img2.png -i img3.png
```

## Options

| Flag | Short | Default | Description |
|------|-------|---------|-------------|
| `--prompt` | `-p` | required | Image description or editing instruction |
| `--filename` | `-f` | required | Output filename |
| `--input-image` | `-i` | — | Input image(s), repeatable, max 14 |
| `--model` | — | `nano-banana` | `nano-banana`, `nano-banana-pro`, or `nano-banana-2` |
| `--resolution` | `-r` | `1K` | `1K`, `2K`, or `4K` |
| `--aspect-ratio` | — | — | e.g. `1:1`, `16:9`, `4:3`, `3:4`, `9:16` |

## API key

The API key is pre-configured on this machine. No flags or environment variables needed.

## Input image handling

All input images are sent as inline base64. Images over 500 KB are automatically compressed to JPEG and resized to fit under the limit. This keeps requests fast and avoids File API auth issues with the enterprise endpoint.

## Output

Relative filenames are saved to `$OPENCLAW_STATE_DIR/media/outbound/{slugid}/nano-banana/{filename}`. Absolute paths are used as-is. Absolute paths are used as-is. Use timestamps in filenames to avoid overwrites: `cat-on-mars-20260304-165000.png`.

## Sending images to the user

The script prints a `MEDIA: <absolute-path>` line on stdout. **You MUST include this exact MEDIA: line in your reply text** so the image is delivered as an attachment in Discord/Slack/chat.

Example reply:
```
Here's your image!
MEDIA: /Users/alche/.openclaw/media/outbound/my-bot/nano-banana/cat-on-mars.png
```

Rules:
- Copy the `MEDIA:` line from the script output into your reply verbatim — this is how images get sent
- Do NOT read the generated image back with the read tool
- Do NOT try to base64 encode or manually attach the image
- The `MEDIA:` line must be on its own line in your response


[View on SkillFed](https://skillfed.io/nexu-io/nexu/nano-banana) · [View on GitHub](https://github.com/nexu-io/nexu)