name	nano-banana-image
description	Use when asked to generate images, create sprites, make visual assets, or produce artwork.
compatibility	Requires nano-banana binary in PATH and GEMINI_API_KEY.

nano-banana-image

AI image generation CLI powered by Gemini image models.

Prerequisites

nano-banana binary in PATH
GEMINI_API_KEY environment variable

If not set up, see references/installation.md.

Quick Reference

# Basic generation
nano-banana "a cat in a spacesuit"

# High-res widescreen
nano-banana "cinematic landscape" -s 2K -a 16:9

# Transparent asset (no external tools needed)
nano-banana "robot mascot" -t -o mascot

# Style transfer from reference image
nano-banana "apply this style to a forest" -r style.png -o forest

# Pro model for highest quality
nano-banana "detailed portrait" -m pro -s 2K

Options

Option	Default	Description
`-o, --output`	`nano-gen-{ts}`	Output filename (no extension)
`-s, --size`	`1K`	Image size: `512`, `1K`, `2K`, `4K`
`-a, --aspect`	model default	Aspect ratio: `1:1`, `16:9`, `9:16`, `4:3`, `3:4`, etc.
`-m, --model`	`flash`	Model: `flash`, `pro`
`-d, --dir`	current directory	Output directory
`-r, --ref`	-	Reference image (repeatable)
`-t, --transparent`	-	Generate with transparent background
`--json`	-	JSON output to stdout
`--plain`	-	Plain output (filenames only)

Models

Alias	Model	Use case
`flash`	Gemini 3.1 Flash	Default. Fast, cheap
`pro`	Gemini 3 Pro	Highest quality

Transparent Mode

-t generates on a green screen, then removes the background using built-in colorkey + despill + trim. Pure Go, no ffmpeg or ImageMagick needed.

Cost Tracking

nano-banana --costs
nano-banana --costs --json

Detailed Installation

See references/installation.md.

name	nano-banana-image
description	Use when asked to generate images, create sprites, make visual assets, or produce artwork.
compatibility	Requires nano-banana binary in PATH and GEMINI_API_KEY.